WorldWideScience

Sample records for low-to-moderate temperature geothermal

  1. Low to moderate temperature nanolaminate heater

    Science.gov (United States)

    Eckels, J Del [Livermore, CA; Nunes, Peter J [Danville, CA; Simpson, Randall L [Livermore, CA; Hau-Riege, Stefan [Fremont, CA; Walton, Chris [Oakland, CA; Carter, J Chance [Livermore, CA; Reynolds, John G [San Ramon, CA

    2011-01-11

    A low to moderate temperature heat source comprising a high temperature energy source modified to output low to moderate temperatures wherein the high temperature energy source modified to output low to moderate temperatures is positioned between two thin pieces to form a close contact sheath. In one embodiment the high temperature energy source modified to output low to moderate temperatures is a nanolaminate multilayer foil of reactive materials that produces a heating level of less than 200.degree. C.

  2. EVALUATION OF ROTARY KILN INCINERATOR OPERATION AT LOW TO MODERATE TEMPERATURE CONDITIONS VOLUME 1. TECHNICAL RESULTS

    Science.gov (United States)

    A test program was performed at the Environmental Protection Agency Incineration Research Facility to study the effectiveness of incineration at low-to-moderate temperatures in decontaminating soils containing organic compounds with different volatilities (boiling points). The da...

  3. Methanol induces low temperature resilient methanogens and improves methane generation from domestic wastewater at low to moderate temperatures.

    Science.gov (United States)

    Saha, Shaswati; Badhe, Neha; De Vrieze, Jo; Biswas, Rima; Nandy, Tapas

    2015-01-01

    Low temperature (methanol is a preferred substrate by methanogens in cold habitats. The study hypothesizes that methanol can induce the growth of low-temperature resilient, methanol utilizing, hydrogenotrophs in UASB reactor. The hypothesis was tested in field conditions to evaluate the impact of seasonal temperature variations on methane yield in the presence and absence of methanol. Results show that 0.04% (v/v) methanol increased methane up to 15 times and its effect was more pronounced at lower temperatures. The qPCR analysis showed the presence of Methanobacteriales along with Methanosetaceae in large numbers. This indicates methanol induced the growth of both the hydrogenotrophic and acetoclastic groups through direct and indirect routes, respectively. This study thus demonstrated that methanol can impart resistance in methanogenic biomass to low temperature and can improve performance of UASB reactor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Comparative experimental and modeling study of the low- to moderate-temperature oxidation chemistry of 2,5-dimethylfuran, 2-methylfuran, and furan

    KAUST Repository

    Tran, Luc-Sy; Wang, Zhandong; Carstensen, Hans-Heinrich; Hemken, Christian; Battin-Leclerc, Fré dé rique; Kohse-Hö inghaus, Katharina

    2017-01-01

    The reaction chemistry of furanic fuels, proposed as next-generation bio-derived fuels, has been a target of recent studies. However, quantitative intermediate species profiles at low- to moderate-temperature (LMT) conditions remain scarce. The present paper reports the first systematic full speciation dataset in the temperature range 730–1170 K for three furanic fuels, 2,5-dimethylfuran (DMF), 2-methylfuran (MF), and furan, measured for different equivalence ratios under near-identical LMT conditions in a flow reactor at 1 bar. More than 35 species including reactants, intermediate species, and products were analyzed using electron ionization (EI) molecular-beam mass spectrometry (MBMS). These experimental results provided motivation to extend a previous single joint mechanism for the three furanic fuels, developed for the high-temperature regime in low-pressure premixed flames, to include the LMT oxidation chemistry. A decisive difference of the present mechanism versus all previously reported models is a more complete description of fuel radical reactions for LMT oxidation, obtained from theoretical calculations of thermodynamic properties and rate constants. The experimentally observed differences in fuel conversion behavior and species distribution between the three fuels have been compared to model predictions using the newly extended mechanism. The dependence of fuel conversion on equivalence ratio decreases significantly from DMF to furan, a behavior consistent with the different number of lateral methyl groups in the fuel structure. All three furanic fuels, especially DMF, produce several highly toxic oxygenated species including acrolein, methyl vinyl ketone, furfural, and phenol. These toxic species were found to be products of the primary reactions of these fuels, and these undesirable trends could be explained satisfactorily by the present model, pointing to some caution with regard to the potential emission spectra under LMT conditions.

  5. Comparative experimental and modeling study of the low- to moderate-temperature oxidation chemistry of 2,5-dimethylfuran, 2-methylfuran, and furan

    KAUST Repository

    Tran, Luc-Sy

    2017-04-21

    The reaction chemistry of furanic fuels, proposed as next-generation bio-derived fuels, has been a target of recent studies. However, quantitative intermediate species profiles at low- to moderate-temperature (LMT) conditions remain scarce. The present paper reports the first systematic full speciation dataset in the temperature range 730–1170 K for three furanic fuels, 2,5-dimethylfuran (DMF), 2-methylfuran (MF), and furan, measured for different equivalence ratios under near-identical LMT conditions in a flow reactor at 1 bar. More than 35 species including reactants, intermediate species, and products were analyzed using electron ionization (EI) molecular-beam mass spectrometry (MBMS). These experimental results provided motivation to extend a previous single joint mechanism for the three furanic fuels, developed for the high-temperature regime in low-pressure premixed flames, to include the LMT oxidation chemistry. A decisive difference of the present mechanism versus all previously reported models is a more complete description of fuel radical reactions for LMT oxidation, obtained from theoretical calculations of thermodynamic properties and rate constants. The experimentally observed differences in fuel conversion behavior and species distribution between the three fuels have been compared to model predictions using the newly extended mechanism. The dependence of fuel conversion on equivalence ratio decreases significantly from DMF to furan, a behavior consistent with the different number of lateral methyl groups in the fuel structure. All three furanic fuels, especially DMF, produce several highly toxic oxygenated species including acrolein, methyl vinyl ketone, furfural, and phenol. These toxic species were found to be products of the primary reactions of these fuels, and these undesirable trends could be explained satisfactorily by the present model, pointing to some caution with regard to the potential emission spectra under LMT conditions.

  6. A hybrid geothermal energy conversion technology: Auxiliary heating of geothermally preheated water or CO2 - a potential solution for low-temperature resources

    Science.gov (United States)

    Saar, Martin; Garapati, Nagasree; Adams, Benjamin; Randolph, Jimmy; Kuehn, Thomas

    2016-04-01

    Safe, sustainable, and economic development of deep geothermal resources, particularly in less favourable regions, often requires employment of unconventional geothermal energy extraction and utilization methods. Often "unconventional geothermal methods" is synonymously and solely used as meaning enhanced geothermal systems, where the permeability of hot, dry rock with naturally low permeability at greater depths (4-6 km), is enhanced. Here we present an alternative unconventional geothermal energy utilization approach that uses low-temperature regions that are shallower, thereby drastically reducing drilling costs. While not a pure geothermal energy system, this hybrid approach may enable utilization of geothermal energy in many regions worldwide that can otherwise not be used for geothermal electricity generation, thereby increasing the global geothermal resource base. Moreover, in some realizations of this hybrid approach that generate carbon dioxide (CO2), the technology may be combined with carbon dioxide capture and storage (CCS) and CO2-based geothermal energy utilization, resulting in a high-efficiency (hybrid) geothermal power plant with a negative carbon footprint. Typically, low- to moderate-temperature geothermal resources are more effectively used for direct heat energy applications. However, due to high thermal losses during transport, direct use requires that the heat resource is located near the user. Alternatively, we show here that if such a low-temperature geothermal resource is combined with an additional or secondary energy resource, the power production is increased compared to the sum from two separate (geothermal and secondary fuel) power plants (DiPippo et al. 1978) and the thermal losses are minimized because the thermal energy is utilized where it is produced. Since Adams et al. (2015) found that using CO2 as a subsurface working fluid produces more net power than brine at low- to moderate-temperature geothermal resource conditions, we

  7. 2014 Low-Temperature and Coproduced Geothermal Resources Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Tim Reinhardt, Program Manager

    2014-09-01

    As a growing sector of geothermal energy development, the Low-Temperature Program supports innovative technologies that enable electricity production and cascaded uses from geothermal resources below 300° Fahrenheit.

  8. High Temperature Perforating System for Geothermal Applications

    Energy Technology Data Exchange (ETDEWEB)

    Smart, Moises E. [Schlumberger Technology Corporation, Sugar Land, TX (United States)

    2017-02-28

    The objective of this project is to develop a perforating system consisting of all the explosive components and hardware, capable of reliable performance in high temperatures geothermal wells (>200 ºC). In this light we will focused on engineering development of these components, characterization of the explosive raw powder and developing the internal infrastructure to increase the production of the explosive from laboratory scale to industrial scale.

  9. Low-temperature geothermal resources of Washington

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, J.E. [Washington State Dept. of Natural Resources, Olympia, WA (United States). Div. of Geology and Earth Resources; Bloomquist, R.G. [Washington State Energy Office, Olympia, WA (United States)

    1994-06-01

    This report presents information on the location, physical characteristics, and water chemistry of low-temperature geothermal resources in Washington. The database includes 941 thermal (>20C or 68F) wells, 34 thermal springs, lakes, and fumaroles, and 238 chemical analyses. Most thermal springs occur in the Cascade Range, and many are associated with stratovolcanoes. In contrast, 97 percent of thermal wells are located in the Columbia Basin of southeastern Washington. Some 83.5 percent are located in Adams, Benton, Franklin, Grant, Walla Walla, and Yakima Counties. Yakima County, with 259 thermal wells, has the most. Thermal wells do not seem to owe their origin to local sources of heat, such as cooling magma in the Earth`s upper crust, but to moderate to deep circulation of ground water in extensive aquifers of the Columbia River Basalt Group and interflow sedimentary deposits, under the influence of a moderately elevated (41C/km) average geothermal gradient.

  10. High-temperature geothermal cableheads

    Science.gov (United States)

    Coquat, J. A.; Eifert, R. W.

    1981-11-01

    Two high temperature, corrosion resistant logging cable heads which use metal seals and a stable fluid to achieve proper electrical terminations and cable sonde interfacings are described. A tensile bar provides a calibrated yield point, and a cone assembly anchors the cable armor to the head. Electrical problems of the sort generally ascribable to the cable sonde interface were absent during demonstration hostile environment loggings in which these cable heads were used.

  11. Relation between 1m depth temperature and average geothermal gradient at 75cm depth in geothermal fields

    OpenAIRE

    江原, 幸雄

    2009-01-01

    Shallow ground temperatures such as 1m depth temperature have been measured to delineate thermal anomalies of geothermal fields and also to estimate heat discharge rates from geothermal fields. As a result, a close linear relation between 1m depth temperature and average geothermal gradient at 75cm depth has been recognized in many geothermal fields and was used to estimate conductive heat discharge rates. However, such a linear relation may show that the shallow thermal regime in geothermal ...

  12. Subsurface temperatures and geothermal gradients on the North Slope, Alaska

    Science.gov (United States)

    Collett, Timothy S.; Bird, Kenneth J.; Magoon, Leslie B.

    1989-01-01

    Geothermal gradients as interpreted from a series of high-resolution stabilized well-bore-temperature surveys from 46 North Slope, Alaska, wells vary laterally and vertically throughout the near-surface sediment (0-2,000 m). The data from these surveys have been used in conjunction with depths of ice-bearing permafrost, as interpreted from 102 well logs, to project geothermal gradients within and below the ice-bearing permafrost sequence. The geothermal gradients calculated from the projected temperature profiles are similar to the geothermal gradients measured in the temperature surveys. Measured and projected geothermal gradients in the ice-bearing permafrost sequence range from 1.5??C/100m in the Prudhoe Bay area to 5.1??C/100m in the National Petroleum Reserve in Alaska (NPRA).

  13. Analysis of Low-Temperature Utilization of Geothermal Resources

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Brian

    2015-06-30

    Full realization of the potential of what might be considered “low-grade” geothermal resources will require that we examine many more uses for the heat than traditional electricity generation. To demonstrate that geothermal energy truly has the potential to be a national energy source we will be designing, assessing, and evaluating innovative uses for geothermal-produced water such as hybrid biomass-geothermal cogeneration of electricity and district heating and efficiency improvements to the use of cellulosic biomass in addition to utilization of geothermal in district heating for community redevelopment projects. The objectives of this project were: 1) to perform a techno-economic analysis of the integration and utilization potential of low-temperature geothermal sources. Innovative uses of low-enthalpy geothermal water were designed and examined for their ability to offset fossil fuels and decrease CO2 emissions. 2) To perform process optimizations and economic analyses of processes that can utilize low-temperature geothermal fluids. These processes included electricity generation using biomass and district heating systems. 3) To scale up and generalize the results of three case study locations to develop a regionalized model of the utilization of low-temperature geothermal resources. A national-level, GIS-based, low-temperature geothermal resource supply model was developed and used to develop a series of national supply curves. We performed an in-depth analysis of the low-temperature geothermal resources that dominate the eastern half of the United States. The final products of this study include 17 publications, an updated version of the cost estimation software GEOPHIRES, and direct-use supply curves for low-temperature utilization of geothermal resources. The supply curves for direct use geothermal include utilization from known hydrothermal, undiscovered hydrothermal, and near-hydrothermal EGS resources and presented these results at the Stanford

  14. Equivalent Circulation Density Analysis of Geothermal Well by Coupling Temperature

    Directory of Open Access Journals (Sweden)

    Xiuhua Zheng

    2017-02-01

    Full Text Available The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties of drilling fluids with temperature are neglected. This paper researched the wellbore pressure coupling by calculating the temperature distribution with the existing model, fitting the rule of density of the drilling fluid with the temperature and establishing mathematical models to simulate the wellbore pressures, which are expressed as the variation of Equivalent Circulating Density (ECD under different conditions. With this method, the temperature and ECDs in the wellbore of the first medium-deep geothermal well, ZK212 Yangyi Geothermal Field in Tibet, were determined, and the sensitivity analysis was simulated by assumed parameters, i.e., the circulating time, flow rate, geothermal gradient, diameters of the wellbore, rheological models and regimes. The results indicated that the geothermal gradient and flow rate were the most influential parameters on the temperature and ECD distribution, and additives added in the drilling fluid should be added carefully as they change the properties of the drilling fluid and induce the redistribution of temperature. To ensure the safe drilling and velocity of pipes tripping into the hole, the depth and diameter of the wellbore are considered to control the surge pressure.

  15. Geothermal gradients in Iraqi Kurdistan deduced from bottom hole temperatures

    OpenAIRE

    Abdula, Rzger A.

    2016-01-01

    Bottom hole temperature (BHT) data from 12 oil wells in Iraqi Kurdistan were used to obtain the thermal trend of Iraqi Kurdistan. Due to differences in thermal conductivity of rocks and groundwater movement, variations in geothermal gradients were observed. The highest geothermal gradient (29.2 °C/km) was found for well Taq Taq-8 in the Low Folded Zone (central part of the area). The lowest geothermal gradients (14.9 °C/km) were observed for well Bekhme-1 in the High Folded Zone (northern and...

  16. Application of subsurface temperature measurements in geothermal prospecting in Iceland

    Science.gov (United States)

    Flóvenz, Ólafur G.

    1985-12-01

    In geothermal areas in Iceland aquifers are in most cases found to occur in highly permeable near-vertical fractures in the low permeability basaltic crust. Therefore heat transfer in the rocks surrounding the aquifers is mainly conductive. Temperature profiles in shallow non-flowing boreholes are used to construct a two dimensional model of the temperature distribution in the vicinity of near vertical aquifers. This is done by finite element solution of the equation of heat transfer which requires knowledge of the regional temperature gradient outside the area of geothermal activity and some constraints on the temperature within the aquifers. The model is helpful in estimating dip and location of near-vertical water bearing fractures and thus in siting production wells. An example of successful use to the method and of soil temperature measurements from a geothermal field in North-Iceland is demonstrated.

  17. Turkey's High Temperature Geothermal Energy Resources and Electricity Production Potential

    Science.gov (United States)

    Bilgin, Ö.

    2012-04-01

    Turkey is in the first 7 countries in the world in terms of potential and applications. Geothermal energy which is an alternative energy resource has advantages such as low-cost, clean, safe and natural resource. Geothermal energy is defined as hot water and steam which is formed by heat that accumulated in various depths of the Earth's crust; with more than 20oC temperature and which contain more than fused minerals, various salts and gases than normal underground and ground water. It is divided into three groups as low, medium and high temperature. High-temperature fluid is used in electricity generation, low and medium temperature fluids are used in greenhouses, houses, airport runways, animal farms and places such as swimming pools heating. In this study high temperature geothermal fields in Turkey which is suitable for electricity production, properties and electricity production potential was investigated.

  18. Geothermal gradients in Iraqi Kurdistan deduced from bottom hole temperatures

    Directory of Open Access Journals (Sweden)

    Rzger A. Abdula

    2017-09-01

    Full Text Available Bottom hole temperature (BHT data from 12 oil wells in Iraqi Kurdistan were used to obtain the thermal trend of Iraqi Kurdistan. Due to differences in thermal conductivity of rocks and groundwater movement, variations in geothermal gradients were observed. The highest geothermal gradient (29.2 °C/km was found for well Taq Taq-8 in the Low Folded Zone (central part of the area. The lowest geothermal gradients (14.9 °C/km were observed for well Bekhme-1 in the High Folded Zone (northern and northeastern parts of the area. The average regional geothermal gradient for Iraqi Kurdistan is 21 °C/km.

  19. Geothermal low-temperature reservoir assessment program: A new DOE geothermal initiative

    International Nuclear Information System (INIS)

    Wright, P.M.; Lienau, P.J.; Mink, L.L.

    1992-01-01

    In Fiscal Year 1991, Congress appropriated money for the Department of Energy to begin a new program in the evaluation and use of low- and moderate-temperature geothermal resources. The objective of this program is to promote accelerated development of these resources to offset fossil-fuel use and help improve the environment. The program will consist of several components, including: (1) compilation of all available information on resource location and characteristics, with emphasis on resources located within 5 miles of population centers; (2) development and testing of techniques to discover and evaluate low- and moderate-temperature geothermal resources; (3) technical assistance to potential developers of low- and moderate-temperature geothermal resources; and (4) evaluation of the use of geothermal heat pumps in domestic and commercial applications. Program participants will include the Geo-Heat Center at the Oregon Institute of Technology, the University of Utah Research Institute, the Idaho Water Resources Research Institute and agencies of state governments in most of the western states

  20. Can high temperature steam electrolysis function with geothermal heat?

    International Nuclear Information System (INIS)

    Sigurvinsson, J.; Mansilla, C.; Werkoff, F.; Lovera, P.

    2007-01-01

    It is possible to improve the performance of electrolysis processes by operating at a high temperature. This leads to a reduction in electricity consumption but requires a part of the energy necessary for the dissociation of water to be in the form of thermal energy. Iceland produces low cost electricity and very low cost geothermal heat. However, the temperature of geothermal heat is considerably lower than the temperature required at the electrolyser's inlet, making heat exchangers necessary to recuperate part of the heat contained in the gases at the electrolyser's outlet. A techno-economic optimisation model devoted to a high-temperature electrolysis (HTE) process which includes electrolysers as well as a high temperature heat exchanger network was created. Concerning the heat exchangers, the unit costs used in the model are based on industrial data. For the electrolyser cells, the unit cost scaling law and the physical sub-model we used were formulated using analogies with solid oxide fuel cells. The method was implemented in a software tool, which performs the optimisation using genetic algorithms. The first application of the method is done by taking into account the prices of electricity and geothermal heat in the Icelandic context. It appears that even with a geothermal temperature as low as 230 degrees C, the HTE could compete with alkaline electrolysis. (authors)

  1. California low-temperature geothermal resources update: 1993

    Energy Technology Data Exchange (ETDEWEB)

    Youngs, L.G.

    1994-12-31

    The US Department of Energy -- Geothermal Division (DOE/GD) recently sponsored the Low-Temperature Geothermal Resources and Technology Transfer Program to bring the inventory of the nation`s low- and moderate-temperature geothermal resources up to date and to encourage development of the resources. The Oregon Institute of Technology, Geo-Heat Center (OIT/GHC) and the University of Utah Research Institute (UURI) established subcontracts and coordinated the project with the state resource teams from the western states that participated in the program. The California Department of Conservation, Division of Mines and Geology (DMG) entered into contract numbered 1092--023(R) with the OIT/GHC to provide the California data for the program. This report is submitted in fulfillment of that contract.

  2. Radon and temperature as tracer of geothermal flow system: application to Arxan geothermal system, Northeastern China

    Science.gov (United States)

    Gu, X.; Shao, J.; Cui, Y.

    2017-12-01

    In this work, hydrogeological and hydrochemical investigations were applied to explain geothermal system factors controlling groundwater mineralization in Arxan geothermal system, Northeastern China. Geothermal water samples were collected from different locations (thermal baths and wells). Radon concentrations of water samples representing different water types and depths were controlled using RAD7. In addition to radon concentration, physical parameters such as temperature (T), pH, electrical conductivity (EC) and TDS were measured in situ, while major ions were analyzed in laboratory. Temperature spatial variability in the study area was described using kriging interpolation method. Hydrochemical analysis and thermal parameters suggest two distinct hydrogeological systems. The first type was dominated by a moderate temperature (25 41°C) with a chemical facies Na-HCO3, which characterizes Jurassic deep water. The second water type was characterized by Ca.Na-HCO3 type with a temperature <25 °C and represents the shallow aquifer. Superficial aquifer displays higher radon concentration (37 to 130 Bq/L), while deep groundwater from Jurassic aquifer shows relatively a low radon concentration (6 to 57.4 Bq/L). Seasonal and geographical variations of radon give insight into the processes controlling radon activities in the Arxan groundwater. Radon concentrations along with spatial distribution of water temperature reveal the existence of vertical communication between shallow aquifer and deep Jurassic aquifer through vertical faults and fractures system, the emanation of radon from thermal water and groundwater is controlled by the geological structure of the area. Furthermore, the knowledge and conclusion demonstrates that combined use of radon and temperature as tracers can give insight into the characteristics of geological structure and geothermal flow system.

  3. Hydrochemical Characteristics and Evolution of Geothermal Fluids in the Chabu High-Temperature Geothermal System, Southern Tibet

    Directory of Open Access Journals (Sweden)

    X. Wang

    2018-01-01

    Full Text Available This study defines reasonable reservoir temperatures and cooling processes of subsurface geothermal fluids in the Chabu high-temperature geothermal system. This system lies in the south-central part of the Shenzha-Xietongmen hydrothermal active belt and develops an extensive sinter platform with various and intense hydrothermal manifestations. All the geothermal spring samples collected systematically from the sinter platform are divided into three groups by cluster analysis of major elements. Samples of group 1 and group 3 are distributed in the central part and northern periphery of the sinter platform, respectively, while samples of group 2 are scattered in the transitional zone between groups 1 and 3. The hydrochemical characteristics show that the geothermal waters of the research area have generally mixed with shallow cooler waters in reservoirs. The reasonable reservoir temperatures and the mixing processes of the subsurface geothermal fluids could be speculated by combining the hydrochemical characteristics of geothermal springs, calculated results of the chemical geothermometers, and silica-enthalpy mixing models. Contour maps are applied to measured emerging temperatures, mass flow rates, total dissolved solids of spring samples, and reasonable subsurface temperatures. They indicate that the major cooling processes of the subsurface geothermal fluids gradually transform from adiabatic boiling to conduction from the central part to the peripheral belt. The geothermal reservoir temperatures also show an increasing trend. The point with the highest reservoir temperature (256°C appears in the east-central part of the research area, which might be the main up-flow zone. The cooling processes of the subsurface geothermal fluids in the research area can be shown on an enthalpy-chloride plot. The deep parent fluid for the Chabu geothermal field has a Cl− concentration of 290 mg/L and an enthalpy of 1550 J/g (with a water temperature of

  4. Geothermal Reservoir Temperatures in Southeastern Idaho using Multicomponent Geothermometry

    Energy Technology Data Exchange (ETDEWEB)

    Neupane, Ghanashyam [Idaho National Lab. (INL) and Center for Advanced Energy Studies, Idaho Falls, ID (United States); Mattson, Earl D. [Idaho National Lab. (INL) and Center for Advanced Energy Studies, Idaho Falls, ID (United States); McLing, Travis L. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Center for Advanced Energy Studies; Palmer, Carl D. [Univ. of Idaho, Idaho Falls, ID (United States); Smith, Robert W. [Univ. of Idaho and Center for Advanced Energy Studies, Idaho Falls, ID (United States); Wood, Thomas R. [Univ. of Idaho and Center for Advanced Energy Studies, Idaho Falls, ID (United States); Podgorney, Robert K. [Idaho National Lab. (INL) and Center for Advanced Energy Studies, Idaho Falls, ID (United States)

    2015-03-01

    Southeastern Idaho exhibits numerous warm springs, warm water from shallow wells, and hot water within oil and gas test wells that indicate a potential for geothermal development in the area. Although the area exhibits several thermal expressions, the measured geothermal gradients vary substantially (19 – 61 ºC/km) within this area, potentially suggesting a redistribution of heat in the overlying ground water from deeper geothermal reservoirs. We have estimated reservoir temperatures from measured water compositions using an inverse modeling technique (Reservoir Temperature Estimator, RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. Compositions of a selected group of thermal waters representing southeastern Idaho hot/warm springs and wells were used for the development of temperature estimates. The temperature estimates in the the region varied from moderately warm (59 ºC) to over 175 ºC. Specifically, hot springs near Preston, Idaho resulted in the highest temperature estimates in the region.

  5. Geothermal Reservoir Temperatures in Southeastern Idaho using Multicomponent Geothermometry

    International Nuclear Information System (INIS)

    Neupane, Ghanashyam; Mattson, Earl D.; McLing, Travis L.; Smith, Robert W.; Wood, Thomas R.; Podgorney, Robert K.

    2015-01-01

    Southeastern Idaho exhibits numerous warm springs, warm water from shallow wells, and hot water within oil and gas test wells that indicate a potential for geothermal development in the area. Although the area exhibits several thermal expressions, the measured geothermal gradients vary substantially (19 - 61 °C/km) within this area, potentially suggesting a redistribution of heat in the overlying ground water from deeper geothermal reservoirs. We have estimated reservoir temperatures from measured water compositions using an inverse modeling technique (Reservoir Temperature Estimator, RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. Compositions of a selected group of thermal waters representing southeastern Idaho hot/warm springs and wells were used for the development of temperature estimates. The temperature estimates in the the region varied from moderately warm (59 °C) to over 175 °C. Specifically, hot springs near Preston, Idaho resulted in the highest temperature estimates in the region.

  6. Companion Study Guide to Short Course on Geothermal Corrosion and Mitigation in Low Temperature Geothermal Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, II, P F

    1985-04-24

    The economic utilization of geothermal resources with temperatures less than 220 degrees Fahrenheit for purposes other than electric power generation (direct utilization) requires creation of systems with long plant life and minimum operation and maintenance costs. Development of such systems requires careful corrosion engineering if the most cost effective material selections and design choices are to be made. This study guide presents guidelines for materials selection for low-temperature geothermal systems (120 - 200 degrees Fahrenheit), as well as guidance in materials design of heat pump systems for very-lowtemperature geothermal resources (less than 120 degrees Fahrenheit). This guideline is divided into five sections and an Appendix.

  7. Low to moderate alcohol intake during pregnancy and risk of psychomotor deficits

    DEFF Research Database (Denmark)

    Bay, Bjørn; Støvring, Henrik; Wimberley, Theresa

    2012-01-01

    Background: To examine the effects of low to moderate alcohol consumption during pregnancy on child motor function at age 5. Methods: A prospective follow-up study of 685 women and their children sampled from the Danish National Birth Cohort based on maternal alcohol consumption during pregnancy...... reporting low to moderate levels of average alcohol consumption during pregnancy and children of mothers who abstained. Conclusions: In this study, we found no systematic association between low to moderate maternal alcohol intake during pregnancy and child motor function at age 5....

  8. Transported Low-Temperature Geothermal Energy for Thermal End Uses Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhiyao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gluesenkamp, Kyle R [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mehdizadeh Momen, Ayyoub [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Li, Jan-Mou [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    The use of geothermal energy is an emerging area for improving the nation’s energy resiliency. Conventionally, geothermal energy applications have focused on power generation using high temperature hydrothermal resources or enhanced geothermal systems. However, many low temperature (below 150°C/300°F) geothermal resources are also available but have not been fully utilized. For example, it is estimated that 25 billion barrels of geothermal fluid (mostly water and some dissolved solids) at 176°F to 302°F (80°C to 150°C) is coproduced annually at oil and gas wells in the United States (DOE 2015). The heat contained in coproduced geothermal fluid (also referred as “coproduced water”) is typically wasted because the fluid is reinjected back into the ground without extracting the heat.

  9. Data Acquisition for Low-Temperature Geothermal Well Tests and Long-Term Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P J

    1992-03-01

    Groundwater monitoring is an essential part of the development of a low-temperature geothermal field for production and injection wells. State water resource and environmental departments are requiring both geothermal well testing and long-term monitoring as a part of the permitting process for geothermal developments. This report covers water-level measurement methods, instruments used for well testing, geochemical sampling, examples of data acquisition and regulatory mandates on groundwater monitoring.

  10. Data acquisition for low-temperature geothermal well tests and long-term monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.

    1992-09-01

    Groundwater monitoring is an essential part of the development of a low-temperature geothermal field for production and injection wells. State water resource and environmental departments are requiring both geothermal well testing and long-term monitoring as a part of the permitting process for geothermal developments. This report covers water-level measurement methods, instruments used for well testing, geochemical sampling, examples of data acquisition and regulatory mandates on groundwater monitoring.

  11. An Estimate of Shallow, Low-Temperature Geothermal Resources of the United States

    Energy Technology Data Exchange (ETDEWEB)

    Mullane, Michelle; Gleason, Michael; Reber, Tim; McCabe, Kevin; Mooney, Meghan; Young, Katherine R.

    2017-05-01

    Low-temperature geothermal resources in the United States potentially hold an enormous quantity of thermal energy, useful for direct use in residential, commercial and industrial applications such as space and water heating, greenhouse warming, pool heating, aquaculture, and low-temperature manufacturing processes. Several studies published over the past 40 years have provided assessments of the resource potential for multiple types of low-temperature geothermal systems (e.g. hydrothermal convection, hydrothermal conduction, and enhanced geothermal systems) with varying temperature ranges and depths. This paper provides a summary and additional analysis of these assessments of shallow (= 3 km), low-temperature (30-150 degrees C) geothermal resources in the United States, suitable for use in direct-use applications. This analysis considers six types of geothermal systems, spanning both hydrothermal and enhanced geothermal systems (EGS). We outline the primary data sources and quantitative parameters used to describe resources in each of these categories, and present summary statistics of the total resources available. In sum, we find that low-temperature hydrothermal resources and EGS resources contain approximately 8 million and 800 million TWh of heat-in-place, respectively. In future work, these resource potential estimates will be used for modeling of the technical and market potential for direct-use geothermal applications for the U.S. Department of Energy's Geothermal Vision Study.

  12. An Estimate of Shallow, Low-Temperature Geothermal Resources of the United States: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Mullane, Michelle; Gleason, Michael; McCabe, Kevin; Mooney, Meghan; Reber, Timothy; Young, Katherine R.

    2016-10-01

    Low-temperature geothermal resources in the United States potentially hold an enormous quantity of thermal energy, useful for direct use in residential, commercial and industrial applications such as space and water heating, greenhouse warming, pool heating, aquaculture, and low-temperature manufacturing processes. Several studies published over the past 40 years have provided assessments of the resource potential for multiple types of low-temperature geothermal systems (e.g. hydrothermal convection, hydrothermal conduction, and enhanced geothermal systems) with varying temperature ranges and depths. This paper provides a summary and additional analysis of these assessments of shallow (= 3 km), low-temperature (30-150 degrees C) geothermal resources in the United States, suitable for use in direct-use applications. This analysis considers six types of geothermal systems, spanning both hydrothermal and enhanced geothermal systems (EGS). We outline the primary data sources and quantitative parameters used to describe resources in each of these categories, and present summary statistics of the total resources available. In sum, we find that low-temperature hydrothermal resources and EGS resources contain approximately 8 million and 800 million TWh of heat-in-place, respectively. In future work, these resource potential estimates will be used for modeling of the technical and market potential for direct-use geothermal applications for the U.S. Department of Energy's Geothermal Vision Study.

  13. Off-design performance analysis of Kalina cycle for low temperature geothermal source

    International Nuclear Information System (INIS)

    Li, Hang; Hu, Dongshuai; Wang, Mingkun; Dai, Yiping

    2016-01-01

    Highlights: • The off-design performance analysis of Kalina cycle is conducted. • The off-design models are established. • The genetic algorithm is used in the design phase. • The sliding pressure control strategy is applied. - Abstract: Low temperature geothermal sources with brilliant prospects have attracted more and more people’s attention. Kalina cycle system using ammonia water as working fluid could exploit geothermal energy effectively. In this paper, the quantitative analysis of off-design performance of Kalina cycle for the low temperature geothermal source is conducted. The off-design models including turbine, pump and heat exchangers are established preliminarily. Genetic algorithm is used to maximize the net power output and determine the thermodynamic parameters in the design phase. The sliding pressure control strategy applied widely in existing Rankine cycle power plants is adopted to response to the variations of geothermal source mass flow rate ratio (70–120%), geothermal source temperature (116–128 °C) and heat sink temperature (0–35 °C). In the off-design research scopes, the guidance for pump rotational speed adjustment is listed to provide some reference for off-design operation of geothermal power plants. The required adjustment rate of pump rotational speed is more sensitive to per unit geothermal source temperature than per unit heat sink temperature. Influence of the heat sink variation is greater than that of the geothermal source variation on the ranges of net power output and thermal efficiency.

  14. Estimation of geothermal gradients from single temperature log-field cases

    International Nuclear Information System (INIS)

    Kutasov, I M; Eppelbaum, L V

    2009-01-01

    A geothermal gradient is one of the most frequently used parameters in logging geophysics. However, the drilling process greatly disturbs the temperature of the formations around the wellbore. For this reason, in order to determine with the required accuracy the formation temperatures and geothermal gradients, a certain length of shut-in time is required. It was shown earlier (Kutasov 1968 Freiberger Forshungshefte C 238 55–61, 1987 Geothermics 16 467–72) that at least two transient temperature surveys are needed to determine the geothermal gradient with adequate accuracy. However, in many cases only one temperature log is conducted in a shut-in borehole. For these cases, we propose an approximate method for the estimation of the geothermal gradient. The utilization of this method is demonstrated on four field examples

  15. High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Turnquist, Norman [GE Global Research, Munchen (Germany); Qi, Xuele [GE Global Research, Munchen (Germany); Raminosoa, Tsarafidy [GE Global Research, Munchen (Germany); Salas, Ken [GE Global Research, Munchen (Germany); Samudrala, Omprakash [GE Global Research, Munchen (Germany); Shah, Manoj [GE Global Research, Munchen (Germany); Van Dam, Jeremy [GE Global Research, Munchen (Germany); Yin, Weijun [GE Global Research, Munchen (Germany); Zia, Jalal [GE Global Research, Munchen (Germany)

    2013-12-20

    This report summarizes the progress made during the April 01, 2010 – December 30, 2013 period under Cooperative Agreement DE-EE0002752 for the U.S. Department of Energy entitled “High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems.” The overall objective of this program is to advance the technology for well fluids lifting systems to meet the foreseeable pressure, temperature, and longevity needs of the Enhanced Geothermal Systems (EGS) industry for the coming ten years. In this program, lifting system requirements for EGS wells were established via consultation with industry experts and site visits. A number of artificial lift technologies were evaluated with regard to their applicability to EGS applications; it was determined that a system based on electric submersible pump (ESP) technology was best suited to EGS. Technical barriers were identified and a component-level technology development program was undertaken to address each barrier, with the most challenging being the development of a power-dense, small diameter motor that can operate reliably in a 300°C environment for up to three years. Some of the targeted individual component technologies include permanent magnet motor construction, high-temperature insulation, dielectrics, bearings, seals, thrust washers, and pump impellers/diffusers. Advances were also made in thermal management of electric motors. In addition to the overall system design for a full-scale EGS application, a subscale prototype was designed and fabricated. Like the full-scale design, the subscale prototype features a novel “flow-through-the-bore” permanent magnet electric motor that combines the use of high temperature materials with an internal cooling scheme that limits peak internal temperatures to <330°C. While the full-scale high-volume multi-stage pump is designed to lift up to 80 kg/s of process water, the subscale prototype is based on a production design that can pump 20 kg/s and has been modified

  16. Hydrogeochemistry of high-temperature geothermal systems in China: A review

    International Nuclear Information System (INIS)

    Guo, Qinghai

    2012-01-01

    As an important part of the Mediterranean-Himalayas geothermal belt, southern Tibet and western Yunnan are the regions of China where high-temperature hydrothermal systems are intensively distributed, of which Rehai, Yangbajing and Yangyi have been investigated systematically during the past several decades. Although much work has been undertaken at Rehai, Yangbajing and Yangyi to study the regional geology, hydrogeology, geothermal geology and geophysics, the emphasis of this review is on hydrogeochemical studies carried out in these geothermal fields. Understanding the geochemistry of geothermal fluids and their environmental impact is critical for sustainable exploitation of high-temperature hydrothermal resources in China. For comparison, the hydrogeochemistry of several similar high-temperature hydrothermal systems in other parts of the world are also included in this review. It has been confirmed by studies on Cl − and stable isotope geochemistry that magma degassing makes an important contribution to the geothermal fluids from Rehai, Yangbajing and Yangyi, though meteoric water is still the major source of recharge for these hydrothermal systems. However, the mechanisms of magma heat sources appear to be quite different in the three systems, as recorded by the 3 He/ 4 He ratios of escaping geothermal gases. A mantle-derived magma intrusion to shallow crust is present below Rehai, although the intruding magma has been heavily hybridized by crustal material. By contrast, the heat sources below Yangbajing and Yangyi are inferred to be remelted continental crust. Besides original sources, the geochemistry of characteristic constituents in the geothermal fluids have also been affected by temperature-dependent fluid–rock interactions, boiling and redox condition changes occurring in the upper part of hydrothermal systems, and mixing with cold near-surface waters. The geothermal fluids from Rehai, Yangbajing and Yangyi contain very high concentrations of some

  17. Mapping temperature and radiant geothermal heat flux anomalies in the Yellowstone geothermal system using ASTER thermal infrared data

    Science.gov (United States)

    Vaughan, R. Greg; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.; Jaworowski, Cheryl; Heasler, Henry

    2012-01-01

    The purpose of this work was to use satellite-based thermal infrared (TIR) remote sensing data to measure, map, and monitor geothermal activity within the Yellowstone geothermal area to help meet the missions of both the U.S. Geological Survey Yellowstone Volcano Observatory and the Yellowstone National Park Geology Program. Specifically, the goals were to: 1) address the challenges of remotely characterizing the spatially and temporally dynamic thermal features in Yellowstone by using nighttime TIR data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and 2) estimate the temperature, geothermal radiant emittance, and radiant geothermal heat flux (GHF) for Yellowstone’s thermal areas (both Park wide and for individual thermal areas). ASTER TIR data (90-m pixels) acquired at night during January and February, 2010, were used to estimate surface temperature, radiant emittance, and radiant GHF from all of Yellowstone’s thermal features, produce thermal anomaly maps, and update field-based maps of thermal areas. A background subtraction technique was used to isolate the geothermal component of TIR radiance from thermal radiance due to insolation. A lower limit for the Yellowstone’s total radiant GHF was established at ~2.0 GW, which is ~30-45% of the heat flux estimated through geochemical (Cl-flux) methods. Additionally, about 5 km2 was added to the geodatabase of mapped thermal areas. This work provides a framework for future satellite-based thermal monitoring at Yellowstone as well as exploration of other volcanic / geothermal systems on a global scale.

  18. Fluid geochemistry and geothermometry applications of the Kangding high-temperature geothermal system in eastern Himalayas

    International Nuclear Information System (INIS)

    Guo, Qi; Pang, Zhonghe; Wang, Yingchun; Tian, Jiao

    2017-01-01

    High-temperature geothermal systems hold an enormous capacity for generating geothermal energy. The Kangding area is a typical high-temperature geothermal field in the Himalayan Geothermal Belt. Hydrogeochemical, gas geochemical and isotopic investigations were performed to identify and qualify the main hydrogeochemical processes affecting thermal water composition, including mixing and degassing, and then to estimate a reliable reservoir temperature. Nine water samples and four geothermal gas samples were collected and analysed for chemical and isotopic components. The results demonstrate the alkaline deep geothermal water is the mixtures of approximately 75% snow-melt water and 25% magmatic water. It is enriched in Na, K, F, Li and other trace elements, indicating the granite reservoir nature. The shallow geothermal water is the mixtures of approximately 30% upward flow of deep geothermal water and 70% meteoric cold water. High concentrations of Ca, Mg and HCO_3 indicate the limestone reservoir nature. There is no remarkable oxygen isotope shift in the geothermal water since the rapid circulation is difficult to trigger off strong water-rock interaction. CO_2 is the predominant geothermal gas, accounting for more than 97% of total gases in volume percentage. The concentration of CO_2 degassing ranged from 0.4 mol L"−"1 to 0.8 mol L"−"1 via geothermometrical modelling. As a result, the geothermal water pH increased from 6.0 to 9.0, and approximately 36% of the total SiO_2 re-precipitate. The sources of CO_2 are the metamorphism of limestone and magmatic degassing based on the composition of carbon isotope. The appropriate geothermometers of Na-K and Na-Li yield reservoir temperature of 280 °C. The geothermometrical modelling, developed to eliminate the effects of CO_2 degassing, yields temperature of 250 °C. The silica-enthalpy mixing model yields temperature of 270 °C with no steam separation before mixing. - Highlights: • Water and gas

  19. Geothermal Small Business Workbook [Geothermal Outreach and Project Financing

    Energy Technology Data Exchange (ETDEWEB)

    Elizabeth Battocletti

    2003-05-01

    Small businesses are the cornerstone of the American economy. Over 22 million small businesses account for approximately 99% of employers, employ about half of the private sector workforce, and are responsible for about two-thirds of net new jobs. Many small businesses fared better than the Fortune 500 in 2001. Non-farm proprietors income rose 2.4% in 2001 while corporate profits declined 7.2%. Yet not all is rosy for small businesses, particularly new ones. One-third close within two years of opening. From 1989 to 1992, almost half closed within four years; only 39.5% were still open after six years. Why do some new businesses thrive and some fail? What helps a new business succeed? Industry knowledge, business and financial planning, and good management. Small geothermal businesses are no different. Low- and medium-temperature geothermal resources exist throughout the western United States, the majority not yet tapped. A recent survey of ten western states identified more than 9,000 thermal wells and springs, over 900 low- to moderate-temperature geothermal resource areas, and hundreds of direct-use sites. Many opportunities exist for geothermal entrepreneurs to develop many of these sites into thriving small businesses. The ''Geothermal Small Business Workbook'' (''Workbook'') was written to give geothermal entrepreneurs, small businesses, and developers the tools they need to understand geothermal applications--both direct use and small-scale power generation--and to write a business and financing plan. The Workbook will: Provide background, market, and regulatory data for direct use and small-scale (< 1 megawatt) power generation geothermal projects; Refer you to several sources of useful information including owners of existing geothermal businesses, trade associations, and other organizations; Break down the complicated and sometimes tedious process of writing a business plan into five easy steps; Lead you

  20. Design A Prototype of Temperature Logging Tools for Geothermal Prospecting Areas

    Directory of Open Access Journals (Sweden)

    Supriyanto

    2013-08-01

    Full Text Available The costs of geothermal exploration are very high because technology is still imported from other countries. The local business players in the geothermal sector do not have the ability to compete with global companies. To reduce costs, we need to develop our own equipment with competitive prices. Here in Indonesia, we have started to design a prototype of temperature logging tools for geothermal prospecting areas. This equipment can be used to detect temperature versus depth variations. To measure the thermal gradient, the platinum resistor temperature sensor is moved slowly down along the borehole. The displacement along the borehole is measured by a rotary encoder. This system is controlled by a 16-bit H8/3069F microcontroller. The acquired temperature data is displayed on a PC monitor using a Python Graphical User Interface. The system has been already tested in the Gunung Pancar geothermal prospect area in Bogor.

  1. Evaluating geothermal and hydrogeologic controls on regional groundwater temperature distribution

    Science.gov (United States)

    Burns, Erick R.; Ingebritsen, Steven E.; Manga, Michael; Williams, Colin F.

    2016-01-01

    A one-dimensional (1-D) analytic solution is developed for heat transport through an aquifer system where the vertical temperature profile in the aquifer is nearly uniform. The general anisotropic form of the viscous heat generation term is developed for use in groundwater flow simulations. The 1-D solution is extended to more complex geometries by solving the equation for piece-wise linear or uniform properties and boundary conditions. A moderately complex example, the Eastern Snake River Plain (ESRP), is analyzed to demonstrate the use of the analytic solution for identifying important physical processes. For example, it is shown that viscous heating is variably important and that heat conduction to the land surface is a primary control on the distribution of aquifer and spring temperatures. Use of published values for all aquifer and thermal properties results in a reasonable match between simulated and measured groundwater temperatures over most of the 300 km length of the ESRP, except for geothermal heat flow into the base of the aquifer within 20 km of the Yellowstone hotspot. Previous basal heat flow measurements (∼110 mW/m2) made beneath the ESRP aquifer were collected at distances of >50 km from the Yellowstone Plateau, but a higher basal heat flow of 150 mW/m2 is required to match groundwater temperatures near the Plateau. The ESRP example demonstrates how the new tool can be used during preliminary analysis of a groundwater system, allowing efficient identification of the important physical processes that must be represented during more-complex 2-D and 3-D simulations of combined groundwater and heat flow.

  2. Subsurface temperatures and geothermal gradients on the north slope of Alaska

    Science.gov (United States)

    Collett, T.S.; Bird, K.J.; Magoon, L.B.

    1993-01-01

    On the North Slope of Alaska, geothermal gradient data are available from high-resolution, equilibrated well-bore surveys and from estimates based on well-log identification of the base of ice-bearing permafrost. A total of 46 North Slope wells, considered to be in or near thermal equilibrium, have been surveyed with high-resolution temperatures devices and geothermal gradients can be interpreted directly from these recorded temperature profiles. To augment the limited North Slope temperature data base, a new method of evaluating local geothermal gradients has been developed. In this method, a series of well-log picks for the base of the ice-bearing permafrost from 102 wells have been used, along with regional temperature constants derived from the high-resolution stabilized well-bore temperature surveys, to project geothermal gradients. Geothermal gradients calculated from the high-resolution temperature surveys generally agree with those projected from known ice-bearing permafrost depths over most of the North Slope. Values in the ice-bearing permafrost range from ??? 1.5??C 100 m in the Prudhoe Bay area to ??? 4.5??C 100 m in the east-central portion of the National Petroleum Reserve in Alaska. Geothermal gradients below the ice-bearing permafrost sequence range from ??? 1.6??C 100 m to ??? 5.2??C 100 m. ?? 1993.

  3. Geothermal studies in China

    International Nuclear Information System (INIS)

    Wang Ji-Yang; Chen Mo-Xiang; Wang Ji-An; Deng Xiao; Wang Jun; Shen Hsien-Chieh; Hsiung Liang-Ping; Yan Shu-Zhen; Fan Zhi-Cheng; Liu Xiu-Wen

    1981-01-01

    Geothermal studies have been conducted in China continuosly since the end of the 1950's with renewed activity since 1970. Three areas of research are defined: (1) fundamental theoretical research of geothermics, including subsurface temperatures, terrestrial heat flow and geothermal modeling; (2) exploration for geothermal resources and exploitation of geothermal energy; (3) geothermal studies in mines. (orig./ME)

  4. Modeling research in low-medium temperature geothermal field, Tianjin

    Institute of Scientific and Technical Information of China (English)

    WANG; Kun(王坤); LI; Chunhua(李春华)

    2002-01-01

    The geothermal reservoir in Tianjin can be divided into two parts: the upper one is the porous medium reservoir in the Tertiary system; the lower one includes the basement reservoir in Lower Paleozoic and Middle-Upper Proterozoic. Hot springs are exposed in the northern mountain and confined geothermal water is imbedded in the southern plain. The geothermal reservoir is incised by several fractures. In recent years, TDS of the geothermal water have gone up along with the production rate increasing, along the eastern fracture zone (Cangdong Fracture and West Baitangkou Fracture). This means that the northern fracture system is the main seepage channel of the deep circulation geothermal water, and the reservoir has good connection in a certain area and definite direction. The isotopic research about hydrogen and carbon chronology indicates that the main recharge period of geothermal water is the Holocene Epoch, the pluvial and chilly period of 20 kaBP. The karst conduits in weathered carbonate rocks of the Proterozoic and Lower Paleozoic and the northeast regional fracture system are the main feeding channels of Tianjin geothermal water. Since the Holocene epoch, the geothermal water stayed at a sealed warm period. The tracer test in WR45 doublet system shows that the tracer test is a very effective measure for understanding the reservoir's transport nature and predicting the cooling time and transport velocity during the reinjection. 3-D numerical simulation shows that if the reinjection well keeps a suitable distance from the production well, reinjection will be a highly effective measure to extract more thermal energy from the rock matrix. The cooling of the production well will not be a problem.

  5. State-coupled low-temperature geothermal-resource assessment program, Fiscal Year 1979. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Icerman, L.; Starkey, A.; Trentman, N. (eds.)

    1980-10-01

    The results of low-temperature geothermal energy resource assessment efforts in New Mexico during the period from 1 October 1978 to 30 June 1980 are summarized. The results of the efforts to extend the inventory of geothermal energy resources in New Mexico to low-temperature geothermal reservoirs with the potential for direct heating applications are given. These efforts focused on compiling basic geothermal data and new hydrology and temperature gradient data throughout New Mexico in a format suitable for direct transfer to the US Geological Survey and the National Oceanic and Atmospheric Administration for inclusion in the GEOTHERM data file and for preparation of New Mexico low-temperature geothermal resources maps. The results of geothermal reservoir confirmation studies are presented. (MHR)

  6. Community structure and function of high-temperature chlorophototrophic microbial mats inhabiting diverse geothermal environments

    DEFF Research Database (Denmark)

    Klatt, Christian G.; Inskeep, William P.; Herrgard, Markus

    2013-01-01

    Six phototrophic microbial mat communities from different geothermal springs (YNP) were studied using metagenome sequencing and geochemical analyses. The primary goals of this work were to determine differences in community composition of high-temperature phototrophic mats distributed across...... the Yellowstone geothermal ecosystem, and to identify metabolic attributes of predominant organisms present in these communities that may correlate with environmental attributes important in niche differentiation. Random shotgun metagenome sequences from six phototrophic communities (average 53Mbp/site) were...

  7. Sperry Low Temperature Geothermal Conversion System, Phase 1 and Phase 2. Volume 3: Systems description

    Science.gov (United States)

    Matthews, H. B.

    The major fraction of hydrothermal resources with the prospect of economic usefulness for the generation of electricity are in the 300(0)F to 425(0)F temperature range. Cost effective conversion of the geothermal energy to electricity requires new ideas to improve conversion efficiency, enhance brine flow, reduce plant costs, increase plant availability, and shorten the time between investment and return. The problems addressed are those inherent in the geothermal environment, in the binary fluid cycle, in the difficulty of efficiently converting the energy of a low temperature resource, and in geothermal economics some of these problems are explained. The energy expended by the down hole pump; the difficulty in designing reliable down hole equipment; fouling of heat exchanger surfaces by geothermal fluids; the unavailability of condenser cooling water at most geothermal sites; the large portion of the available energy used by the feed pump in a binary system; the pinch effect, a loss in available energy in transferring heat from water to an organic fluid; flow losses in fluids that carry only a small amount of useful energy to begin with; high heat exchanger costs, the lower the temperature interval of the cycle, the higher the heat exchanger costs in $/kW; the complexity and cost of the many auxiliary elements of proposed geothermal plants; and the unfortunate cash flow vs. investment curve caused by the many years of investment required to bring a field into production before any income is realized.

  8. Low Temperature Geothermal Resource Assessment for Membrane Distillation Desalination in the United States: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Akar, Sertac; Turchi, Craig

    2016-10-01

    Substantial drought and declines in potable groundwater in the United States over the last decade has increased the demand for fresh water. Desalination of saline water such as brackish surface or groundwater, seawater, brines co-produced from oil and gas operations, industrial wastewater, blow-down water from power plant cooling towers, and agriculture drainage water can reduce the volume of water that requires disposal while providing a source of high-quality fresh water for industrial or commercial use. Membrane distillation (MD) is a developing technology that uses low-temperature thermal energy for desalination. Geothermal heat can be an ideal thermal-energy source for MD desalination technology, with a target range of $1/m3 to $2/m3 for desalinated water depending on the cost of heat. Three different cases were analyzed to estimate levelized cost of heat (LCOH) for integration of MD desalination technology with low-grade geothermal heat: (1) residual heat from injection brine at a geothermal power plant, (2) heat from existing underutilized low-temperature wells, and (3) drilling new wells for low-temperature resources. The Central and Western United States have important low-temperature (<90 degrees C) geothermal resource potential with wide geographic distribution, but these resources are highly underutilized because they are inefficient for power production. According to the USGS, there are 1,075 identified low temperature hydrothermal systems, 55 low temperature sedimentary systems and 248 identified medium to high temperature geothermal systems in the United States. The estimated total beneficial heat potential from identified low temperature hydrothermal geothermal systems and residual beneficial heat from medium to high temperature systems is estimated as 36,300 MWth, which could theoretically produce 1.4 to 7 million m3/day of potable water, depending on desalination efficiency.

  9. Low Temperature Geothermal Resource Assessment for Membrane Distillation Desalination in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Akar, Sertac; Turchi, Craig

    2017-05-01

    Substantial drought and declines in potable groundwater in the United States over the last decade has increased the demand for fresh water. Desalination of saline water such as brackish surface or groundwater, seawater, brines co-produced from oil and gas operations, industrial wastewater, blow-down water from power plant cooling towers, and agriculture drainage water can reduce the volume of water that requires disposal while providing a source of high-quality fresh water for industrial or commercial use. Membrane distillation (MD) is a developing technology that uses low-temperature thermal energy for desalination. Geothermal heat can be an ideal thermal-energy source for MD desalination technology, with a target range of $1/m3 to $2/m3 for desalinated water depending on the cost of heat. Three different cases were analyzed to estimate levelized cost of heat (LCOH) for integration of MD desalination technology with low-grade geothermal heat: (1) residual heat from injection brine at a geothermal power plant, (2) heat from existing underutilized low-temperature wells, and (3) drilling new wells for low-temperature resources. The Central and Western United States have important low-temperature (<90 degrees C) geothermal resource potential with wide geographic distribution, but these resources are highly underutilized because they are inefficient for power production. According to the USGS, there are 1,075 identified low temperature hydrothermal systems, 55 low temperature sedimentary systems and 248 identified medium to high temperature geothermal systems in the United States. The estimated total beneficial heat potential from identified low temperature hydrothermal geothermal systems and residual beneficial heat from medium to high temperature systems is estimated as 36,300 MWth, which could theoretically produce 1.4 to 7 million m3/day of potable water, depending on desalination efficiency.

  10. New Mexico low-temperature geothermal resources and economic development programs

    International Nuclear Information System (INIS)

    Whittier, J.; Schoenmackers, R.

    1990-01-01

    This paper reports on New Mexico's low-temperature geothermal resources which have been utilized to promote economic development initiatives within the state. Public funds have been leveraged to foster exploration activities which have led to the establishment of several direct-use projects at various sites within New Mexico. State policies have focused on attracting one business sector, the commercial greenhouse industry, to expand and/or relocate in New Mexico. Geothermal-related promotional activities have begun to show success in achieving economic growth. New Mexico now has almost half of the geothermally-heated greenhouse space in the nation. It is anticipated that the greenhouse sector will continue to grow within the state. Future economic development activities, also relying upon the geothermal resource base, will include vegetable dehydration and aquaculture with a focus on the microalgae sector

  11. Economic impact of using nonmetallic materials in low to intermediate temperature geothermal well construction

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    Four appendices are included. The first covers applications of low-temperature geothermal energy including industrial processes, agricultural and related processes, district heating and cooling, and miscellaneous. The second discusses hydrogeologic factors affecting the design and construction of low-temperature geothermal wells: water quality, withdrawal rate, water depth, water temperature, basic well designs, and hydrogeologic provinces. In the third appendix, properties of metallic and nonmetallic materials are described, including: specific gravity, mechanical strength properties, resistance to physical and biological attack, thermal properties of nonmetallics, fluid flow characteristics, corrosion resistance, scaling resistance, weathering resistance of nonmetallics, and hydrolysis resistance of nonmetallics. Finally, special considerations in the design and construction of low-temperature geothermal wells using nonmetallics materials are covered. These include; drilling methods, joining methods, methods of casing and screen installation, well cementing, and well development. (MHR)

  12. Data assimilation for the investigation of deep temperature and geothermal energy in the Netherlands.

    Science.gov (United States)

    Bonté, Damien; Limberger, Jon; Lipsey, Lindsey; Cloetingh, Sierd; van Wees, Jan-Diederik

    2016-04-01

    Deep geothermal energy systems, mostly for the direct use of heat, have been attracting more and more interest in the past 10 years in Western Europe. In the Netherlands, where the sector took off with the first system in 2005, geothermal energy is seen has a key player for a sustainable future. To support the development of deep geothermal energy system, the scientific community has been working on tools that could be used to highlight area of potential interest for geothermal exploration. In the Netherlands, ThermoGIS is one such tool that has been developed to inform the general public, policy makers, and developers in the energy sector of the possibility of geothermal energy development. One major component incorporated in this tool is the temperature model. For the Netherlands, we created a thermal model at the lithospheric scale that focus on the sedimentary deposits for deep geothermal exploration. This regional thermal modelling concentrates on the variations of geological thermal conductivity and heat production both in the sediments and in the crust. In addition, we carried out special modelling in order to specifically understand convectivity in the basin, focusing on variations at a regional scale. These works, as well as recent improved of geological knowledge in the deeper part of the basin, show interesting evidence for geothermal energy development. At this scale, the aim of this work is to build on these models and, using data assimilation, to discriminate in the actual causes of the observed anomalies. The temperature results obtained for the Netherlands show some thermal patterns that relate to the variation of the thermal conductivity and the geometry of the sediments. There is also strong evidence to indicate that deep convective flows are responsible for thermal anomalies. The combination of conductive and local convective thermal patterns makes the deeper part of the Dutch sedimentary basin of great interest for the development of geothermal

  13. Potential decline in geothermal energy generation due to rising temperatures under climate change scenarios

    Science.gov (United States)

    Angel, E.; Ortega, S.; Gonzalez-Duque, D.; Ruiz-Carrascal, D.

    2016-12-01

    Geothermal energy production depends on the difference between air temperature and the geothermal fluid temperature. The latter remains approximately constant over time, so the power generation varies according to local atmospheric conditions. Projected changes in near-surface air temperatures in the upper levels of the tropical belt are likely to exceed the projected temperature anomalies across many other latitudes, which implies that geothermal plants located in these regions may be affected, reducing their energy output. This study focuses on a hypothetical geothermal power plant, located in the headwaters of the Claro River watershed, a key high-altitude basin in Los Nevados Natural Park, on the El Ruiz-Tolima volcanic massif, in the Colombian Central Andes, a region with a known geothermal potential. Four different Atmospheric General Circulation Models where used to project temperature anomalies for the 2040-2069 prospective period. Their simulation outputs were merged in a differentially-weighted multi-model ensemble, whose weighting factors were defined according to the capability of individual models to reproduce ground truth data from a set of digital data-loggers installed in the basin since 2008 and from weather stations gathering climatic variables since the early 50s. Projected anomalies were computed for each of the Representative Concentration Pathways defined by the IPCC Fifth Assessment Report in the studied region. These climate change projections indicate that air temperatures will likely reach positive anomalies in the range +1.27 ºC to +3.47 ºC, with a mean value of +2.18 ºC. Under these conditions, the annual energy output declines roughly 1% per each degree of increase in near-surface temperature. These results must be taken into account in geothermal project evaluations in the region.

  14. DETERMINING UNDISTURBED GROUND TEMPERATURE AS PART OF SHALLOW GEOTHERMAL RESOURCES ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Tomislav Kurevija

    2010-12-01

    Full Text Available The undisturbed ground temperature is one of the key thermogeological parameters for the assessment and utilization of shallow geothermal resources. Geothermal energy is the type of energy which is stored in the ground where solar radiation has no effect. The depth at which the undisturbed ground temperature occurs, independent of seasonal changes in the surface air temperature, is functionally determined by climate parameters and thermogeological properties. In deeper layers, the increase of ground temperature depends solely on geothermal gradient. Determining accurate values of undisturbed ground temperature and depth of occurrence is crucial for the correct sizing of a borehole heat exchanger as part of the ground-source heat pump system, which is considered the most efficient technology for utilising shallow geothermal resources. The purpose of this paper is to define three specific temperature regions, based on the measured ground temperature data collected from the main meteorological stations in Croatia. The three regions are: Northern Croatia, Adriatic region, and the regions of Lika and Gorski Kotar.

  15. Deep Geothermal Reservoir Temperatures in the Eastern Snake River Plain, Idaho using Multicomponent Geothermometry

    Energy Technology Data Exchange (ETDEWEB)

    Ghanashyam Neupane; Earl D. Mattson; Travis L. McLing; Carl D. Palmer; Robert W. Smith; Thomas R. Wood

    2014-02-01

    The U.S. Geological survey has estimated that there are up to 4,900 MWe of undiscovered geothermal resources and 92,000 MWe of enhanced geothermal potential within the state of Idaho. Of particular interest are the resources of the Eastern Snake River Plain (ESRP) which was formed by volcanic activity associated with the relative movement of the Yellowstone Hot Spot across the state of Idaho. This region is characterized by a high geothermal gradient and thermal springs occurring along the margins of the ESRP. Masking much of the deep thermal potential of the ESRP is a regionally extensive and productive cold-water aquifer. We have undertaken a study to infer the temperature of the geothermal system hidden beneath the cold-water aquifer of the ESRP. Our approach is to estimate reservoir temperatures from measured water compositions using an inverse modeling technique (RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. In the initial stages of this study, we apply the RTEst model to water compositions measured from a limited number of wells and thermal springs to estimate the regionally extensive geothermal system in the ESRP.

  16. The Hengill geothermal area, Iceland: Variation of temperature gradients deduced from the maximum depth of seismogenesis

    Science.gov (United States)

    Foulger, G. R.

    1995-04-01

    Given a uniform lithology and strain rate and a full seismic data set, the maximum depth of earthquakes may be viewed to a first order as an isotherm. These conditions are approached at the Hengill geothermal area S. Iceland, a dominantly basaltic area. The likely strain rate calculated from thermal and tectonic considerations is 10 -15 s -1, and temperature measurements from four drill sites within the area indicate average, near-surface geothermal gradients of up to 150 °C km -1 throughout the upper 2 km. The temperature at which seismic failure ceases for the strain rates likely at the Hengill geothermal area is determined by analogy with oceanic crust, and is about 650 ± 50 °C. The topographies of the top and bottom of the seismogenic layer were mapped using 617 earthquakes located highly accurately by performing a simultaneous inversion for three-dimensional structure and hypocentral parameters. The thickness of the seismogenic layer is roughly constant and about 3 km. A shallow, aseismic, low-velocity volume within the spreading plate boundary that crosses the area occurs above the top of the seismogenic layer and is interpreted as an isolated body of partial melt. The base of the seismogenic layer has a maximum depth of about 6.5 km beneath the spreading axis and deepens to about 7 km beneath a transform zone in the south of the area. Beneath the high-temperature part of the geothermal area, the maximum depth of earthquakes may be as shallow as 4 km. The geothermal gradient below drilling depths in various parts of the area ranges from 84 ± 9 °Ckm -1 within the low-temperature geothermal area of the transform zone to 138 ± 15 °Ckm -1 below the centre of the high-temperature geothermal area. Shallow maximum depths of earthquakes and therefore high average geothermal gradients tend to correlate with the intensity of the geothermal area and not with the location of the currently active spreading axis.

  17. Temperature logging of groundwater in bedrock wells for geothermal gradient characterization in New Hampshire, 2012

    Science.gov (United States)

    Degnan, James; Barker, Gregory; Olson, Neil; Wilder, Leland

    2012-01-01

    The U.S. Geological Survey, in cooperation with the New Hampshire Geological Survey, measured the fluid temperature of groundwater in deep bedrock wells in the State of New Hampshire in order to characterize geothermal gradients in bedrock. All wells selected for the study had low water yields, which correspond to low groundwater flow from fractures. This reduced the potential for flow-induced temperature changes that would mask the natural geothermal gradient in the bedrock. All the wells included in this study were privately owned, and permission to use the wells was obtained from homeowners before logging.

  18. [Geothermal system temperature-depth database and model for data analysis]. 5. quarterly technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Blackwell, D.D.

    1998-04-25

    During this first quarter of the second year of the contract activity has involved several different tasks. The author has continued to work on three tasks most intensively during this quarter: the task of implementing the data base for geothermal system temperature-depth, the maintenance of the WWW site with the heat flow and gradient data base, and finally the development of a modeling capability for analysis of the geothermal system exploration data. The author has completed the task of developing a data base template for geothermal system temperature-depth data that can be used in conjunction with the regional data base that he had already developed and is now implementing it. Progress is described.

  19. Geomagnetic Survey to Explore High-Temperature Geothermal System in Blawan-Ijen, East Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Daud Yunus

    2018-01-01

    Full Text Available Ijen geothermal area is high-temperature geothermal system located in Bondowoso regency, East Java. It is categorized as caldera-hosted geothermal system which is covered by quaternary andesitic volcanic rocks with steep topography at the surrounding. Several surface thermal manifestations are found, such as altered rocks near Mt. Kukusan and a group of Blawan hotsprings in the northern part of the caldera. Geomagnetic survey was conducted at 72 stations which is distributed inside the caldera to delineate the existence of hydrothermal activity. Magnetic anomaly was obtained by reducing total magnetic measured on the field by IGRF and diurnal variation. Reduction to pole (RTP method was applied with geomagnetic inclination of about -32°. In general, the result shows that high magnetic anomaly is distributed at the boundary of study area, while low magnetic anomaly is observed in the centre. The low anomaly indicates demagnetized rock that probably caused by hydrothermal activity. It has a good correlation with surface alteration observed close to Mt. Kukusan as well as high temperature reservoir drilled in the centre of caldera. Accordingly, the low magnetic anomaly also presents the possibility of geothermal reservoir in Ijen geothermal area.

  20. Geomagnetic Survey to Explore High-Temperature Geothermal System in Blawan-Ijen, East Java, Indonesia

    Science.gov (United States)

    Daud, Yunus; Rosid, Syamsu; Fahmi, Fikri; Yunus, Faris Maulana; Muflihendri, Reza

    2018-02-01

    Ijen geothermal area is high-temperature geothermal system located in Bondowoso regency, East Java. It is categorized as caldera-hosted geothermal system which is covered by quaternary andesitic volcanic rocks with steep topography at the surrounding. Several surface thermal manifestations are found, such as altered rocks near Mt. Kukusan and a group of Blawan hotsprings in the northern part of the caldera. Geomagnetic survey was conducted at 72 stations which is distributed inside the caldera to delineate the existence of hydrothermal activity. Magnetic anomaly was obtained by reducing total magnetic measured on the field by IGRF and diurnal variation. Reduction to pole (RTP) method was applied with geomagnetic inclination of about -32°. In general, the result shows that high magnetic anomaly is distributed at the boundary of study area, while low magnetic anomaly is observed in the centre. The low anomaly indicates demagnetized rock that probably caused by hydrothermal activity. It has a good correlation with surface alteration observed close to Mt. Kukusan as well as high temperature reservoir drilled in the centre of caldera. Accordingly, the low magnetic anomaly also presents the possibility of geothermal reservoir in Ijen geothermal area.

  1. Light hydrocarbons as redox and temperature indicators in the geothermal field of El Tatio (northern Chile)

    Energy Technology Data Exchange (ETDEWEB)

    Tassi, F. [University of Florence (Italy). Dept. of Earth Sciences; Martinez, C. [University Catolica del Norte, Antofagasta (Chile). Dept. of Earth Science; Vaselli, O. [University of Florence (Italy). Dept. of Earth Sciences; Institute of Geosciences and Earth Resources, Florence (Italy). National Council of Research; Capaccioni, B. [University of Urbino (Italy). Institute of Volcanology and Geochemistry; Viramonte, J. [National University of Salta (Argentina). Institute GEONORTE and CONICET

    2005-11-15

    El Tatio (northern Chile), one of the largest geothermal fields of South America, is presently undergoing a new program of geothermal exploration, after the failure of the first exploration phase in the early 1970s. The geochemical features of the fluid discharges characterizing this system mainly consist of boiling pools and fumaroles, and represent the result of a complex mixing process involving 3 main components: (i) hydrothermal; (ii) atmospheric; (iii) magmatic. Chemical reactions involving light hydrocarbons equilibrate at higher temperature than those directly measured in the geothermal wells and calculated on the basis of the composition of the inorganic gas species. This suggests that in the deeper parts of the hydrothermal system temperatures higher than 300{sup o}C may be achieved. Such results can have a strong impact for the evaluation of the potential resources of this geothermal system. Moreover, the chemical characteristics of the organic gas fraction allow the assessment of the chemical-physical conditions governing the geochemical processes acting on geothermal fluids at depth. (author)

  2. Prospects of development of highly mineralized high-temperature resources of the Tarumovskoye geothermal field

    Science.gov (United States)

    Alkhasov, A. B.; Alkhasova, D. A.; Ramazanov, A. Sh.; Kasparova, M. A.

    2016-06-01

    The promising nature of integrated processing of high-temperature geothermal brines of the Tarumovskoye geothermal field is shown. Thermal energy of a geothermal brine can be converted to the electric power at a binary geothermal power plant (GPP) based on low-boiling working substance. The thermodynamic Rankine cycles are considered which are implemented in the GPP secondary loop at different evaporation temperatures of the working substance―isobutane. Among them, the most efficient cycle from the standpoint of attaining a maximum power is the supercritical one which is close to the so-called triangular cycle with an evaporation pressure of p e = 5.0 MPa. The used low-temperature brine is supplied from the GPP to a chemical plant, where main chemical components (lithium carbonate, burnt magnesia, calcium carbonate, and sodium chloride) are extracted from it according to the developed technology of comprehensive utilization of geothermal brines of chloride-sodium type. The waste water is delivered to the geotechnological complex and other consumers. For producing valuable inorganic materials, the electric power generated at the GPP is used. Owing to this, the total self-sufficiency of production and independence from external conditions is achieved. The advantages of the proposed geotechnological complex are the full utilization of the heat potential and the extraction of main chemical components of multiparameter geothermal resources. In this case, there is no need for reverse pumping, which eliminates the significant capital costs for building injection wells and a pumping station and the operating costs for their service. A characteristic of the modern state of the field and estimated figures of the integrated processing of high-temperature brines of well no. 6 are given, from which it follows that the proposed technology has a high efficiency. The comprehensive development of the field resources will make it possible to improve the economic structure of the

  3. Use of Low-Temperature Geothermal Energy for Desalination in the Western United States

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Akar, Sertac [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cath, Tzahi [Colorado School of Mines, Golden, CO (United States); Vanneste, Johan [Colorado School of Mines, Golden, CO (United States); Geza, Mengistu [Colorado School of Mines, Golden, CO (United States)

    2015-11-01

    This joint project between the National Renewable Energy Laboratory and the Colorado School of Mines has examined the potential of using low-temperature geothermal resources for desalination. The temperature range in question is not well suited for electricity generation, but can be used for direct heating. Accordingly, the best integration approaches use thermal desalination technologies such as multi-effect distillation (MED) or membrane distillation (MD), rather than electric-driven technologies such as reverse osmosis (RO). The examination of different desalination technologies led to the selection of MD for pairing with geothermal energy. MD operates at near-ambient pressure and temperatures less than 100°C with hydrophobic membranes. The technology is modular like RO, but the equipment costs are lower. The thermal energy demands of MD are higher than MED, but this is offset by an ability to run at lower temperatures and a low capital cost. Consequently, a geothermal-MD system could offer a low capital cost and, if paired with low-cost geothermal energy, a low operating cost. The target product water cost is $1.0 to $1.5 per cubic meter depending on system capacity and the cost of thermal energy.

  4. Better temperature predictions in geothermal modelling by improved quality of input parameters

    DEFF Research Database (Denmark)

    Fuchs, Sven; Bording, Thue Sylvester; Balling, N.

    2015-01-01

    Thermal modelling is used to examine the subsurface temperature field and geothermal conditions at various scales (e.g. sedimentary basins, deep crust) and in the framework of different problem settings (e.g. scientific or industrial use). In such models, knowledge of rock thermal properties...

  5. Demonstration of a Variable Phase Turbine Power System for Low Temperature Geothermal Resources

    Energy Technology Data Exchange (ETDEWEB)

    Hays, Lance G

    2014-07-07

    A variable phase turbine assembly will be designed and manufactured having a turbine, operable with transcritical, two-phase or vapor flow, and a generator – on the same shaft supported by process lubricated bearings. The assembly will be hermetically sealed and the generator cooled by the refrigerant. A compact plate-fin heat exchanger or tube and shell heat exchanger will be used to transfer heat from the geothermal fluid to the refrigerant. The demonstration turbine will be operated separately with two-phase flow and with vapor flow to demonstrate performance and applicability to the entire range of low temperature geothermal resources. The vapor leaving the turbine is condensed in a plate-fin refrigerant condenser. The heat exchanger, variable phase turbine assembly and condenser are all mounted on single skids to enable factory assembly and checkout and minimize installation costs. The system will be demonstrated using low temperature (237F) well flow from an existing large geothermal field. The net power generated, 1 megawatt, will be fed into the existing power system at the demonstration site. The system will demonstrate reliable generation of inexpensive power from low temperature resources. The system will be designed for mass manufacturing and factory assembly and should cost less than $1,200/kWe installed, when manufactured in large quantities. The estimated cost of power for 300F resources is predicted to be less than 5 cents/kWh. This should enable a substantial increase in power generated from low temperature geothermal resources.

  6. Determination of Ground Heat Exchangers Temperature Field in Geothermal Heat Pumps

    Science.gov (United States)

    Zhurmilova, I.; Shtym, A.

    2017-11-01

    For the heating and cooling supply of buildings and constructions geothermal heat pumps using low-potential ground energy are applied by means of ground exchangers. The process of heat transfer in a system of ground exchangers is a phenomenon of complex heat transfer. The paper presents a mathematical modeling of heat exchange processes, the temperature fields are built which are necessary for the determination of the ground array that ensures an adequate supply of low potential energy excluding the freezing of soil around the pipes in the ground heat exchangers and guaranteeing a reliable operation of geothermal heat pumps.

  7. Economic study of low temperature geothermal energy in Lassen and Modoc Counties, California

    Energy Technology Data Exchange (ETDEWEB)

    1977-04-01

    The feasibility of using low cost, low temperature geothermal energy in job-producing industries to increase employment and encourage economic development was investigated. The study, encompassing all of Lassen and Modoc Counties, was to be site-specific, referencing candidate geothermal applications to known hot wells and springs as previously determined, or to new wells with specific characteristics as defined in the Scope of Work. The emphasis was to be placed on economically practical and readily achievable applications from known resources. Although both positive and negative findings were found in specific areas of investigation, it is felt that the overall long term prognosis for geothermal energy stimulus to industry in the area is excellent. The applications studied were; greenhouse heating, kiln drying, onion dehydration, feedlots, and aquaculture.

  8. District space heating potential of low temperature hydrothermal geothermal resources in the southwestern United States. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    McDevitt, P.K.; Rao, C.R.

    1978-10-01

    A computer simulation model (GIRORA-Nonelectric) is developed to study the economics of district space heating using geothermal energy. GIRORA-Nonelectric is a discounted cashflow investment model which evaluates the financial return on investment for space heating. This model consists of two major submodels: the exploration for and development of a geothermal anomaly by a geothermal producer, and the purchase of geothermal fluid by a district heating unit. The primary output of the model is a calculated rate of return on investment earned by the geothermal producer. The results of the sensitivity analysis of the model subject to changes in physical and economic parameters are given in this report. Using the results of the economic analysis and technological screening criteria, all the low temperature geothermal sites in Southwestern United States are examined for economic viability for space heating application. The methodology adopted and the results are given.

  9. Efficacy of low to moderate doses of oxcarbazepine in adult patients with newly diagnosed partial epilepsy.

    Science.gov (United States)

    Zou, Xue-Mei; Chen, Jia-Ni; An, Dong-Mei; Hao, Nan-Ya; Hong, Zhen; Hao, Xiao-Ting; Rao, Ping; Zhou, Dong

    2015-07-01

    The objective of this study was to explore the efficacy of low dose of oxcarbazepine (OXC) in adult patients with newly diagnosed partial epilepsy in an actual clinical setting. The associated factors influencing the poor control of seizures were also evaluated. The epilepsy database (2010-2014) from the Epilepsy Clinic of West China Hospital was retrospectively reviewed. A total of 102 adult patients with newly diagnosed, previously untreated partial epilepsy initially treated with OXC were included, and divided into good response group (64) and poor response group (38) according to whether they were seizure-free for at least 12 months. There were 27 (26.5%) patients becoming seizure-free with OXC 600 mg/day monotherapy. The remaining 75 patients had doses of either increasing OXC to 900 mg/day (n = 59) or the addition of another antiepileptic drug (AED) (n = 16), with another 20 (19.6%) and six (5.9%) patients becoming seizure-free, respectively (P = 0.788). In addition, two (2.0%) and nine (8.8%) patients became seizure-free with OXC > 900 mg/day monotherapy and OXC ≥ 900 mg/day combination therapy, respectively. Multivariate binary logistic regression analysis revealed that the time from onset of epilepsy to treatment initiation is significantly associated with seizure control (P = 0.02). Our results indicated that OXC at low to moderate doses is effective for the treatment of Chinese adult patients with newly diagnosed, previously untreated partial epilepsy, and a longer time interval from the onset of epilepsy to the start of treatment significantly predicts poor seizure control. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  10. Acute Exposure to Low-to-Moderate Carbon Dioxide Levels and Submariner Decision Making.

    Science.gov (United States)

    Rodeheffer, Christopher D; Chabal, Sarah; Clarke, John M; Fothergill, David M

    2018-06-01

    Submarines routinely operate with higher levels of ambient carbon dioxide (CO2) (i.e., 2000 - 5000 ppm) than what is typically considered normal (i.e., 400 - 600 ppm). Although significant cognitive impairments are rarely reported at these elevated CO2 levels, recent studies using the Strategic Management Simulation (SMS) test have found impairments in decision-making performance during acute CO2 exposure at levels as low as 1000 ppm. This is a potential concern for submarine operations, as personnel regularly make mission-critical decisions that affect the safety and efficiency of the vessel and its crew while exposed to similar levels of CO2. The objective of this study was to determine if submariner decision-making performance is impacted by acute exposure to levels of CO2 routinely present in the submarine atmosphere during sea patrols. Using a subject-blinded balanced design, 36 submarine-qualified sailors were randomly assigned to receive 1 of 3 CO2 exposure conditions (600, 2500, or 15,000 ppm). After a 45-min atmospheric acclimation period, participants completed an 80-min computer-administered SMS test as a measure of decision making. There were no significant differences for any of the nine SMS measures of decision making between the CO2 exposure conditions. In contrast to recent research demonstrating cognitive deficits on the SMS test in students and professional-grade office workers, we were unable to replicate this effect in a submariner population-even with acute CO2 exposures more than an order of magnitude greater than those used in previous studies that demonstrated such effects.Rodeheffer CD, Chabal S, Clarke JM, Fothergill DM. Acute exposure to low-to-moderate carbon dioxide levels and submariner decision making. Aerosp Med Hum Perform. 2018; 89(6):520-525.

  11. THE MAXIMUM EFFECT OF DEEP LAKES ON TEMPERATURE PROFILES – DETERMINATION OF THE GEOTHERMAL GRADIENT

    Directory of Open Access Journals (Sweden)

    Eppelbaum L. V.

    2009-07-01

    Full Text Available Understanding the climate change processes on the basis of geothermal observations in boreholes is an important and at the same time high-intricate problem. Many non-climatic effects could cause changes in ground surface temperatures. In this study we investigate the effects of deep lakes on the borehole temperature profilesobserved within or in the vicinity of the lakes. We propose a method based on utilization of Laplace equation with nonuniform boundary conditions. The proposed method makes possible to estimate the maximum effect of deep lakes (here the term "deep lake" means that long term mean annual temperature of bottom sediments can beconsidered as a constant value on the borehole temperature profiles. This method also allows one to estimate an accuracy of the determination of the geothermal gradient.

  12. Advanced Low Temperature Geothermal Power Cycles (The ENTIV Organic Project) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mugerwa, Michael [Technip USA, Inc., Claremont, CA (United States)

    2015-11-18

    Feasibility study of advanced low temperature thermal power cycles for the Entiv Organic Project. Study evaluates amonia-water mixed working fluid energy conversion processes developed and licensed under Kalex in comparison with Kalina cycles. Both cycles are developed using low temperature thermal resource from the Lower Klamath Lake Geothermal Area. An economic feasibility evaluation was conducted for a pilot plant which was deemed unfeasible by the Project Sponsor (Entiv).

  13. Numerical investigation on the implications of spring temperature and discharge rate with respect to the geothermal background in a fault zone

    Science.gov (United States)

    Jiang, Zhenjiao; Xu, Tianfu; Mariethoz, Gregoire

    2018-04-01

    Geothermal springs are some of the most obvious indicators of the existence of high-temperature geothermal resources in the subsurface. However, geothermal springs can also occur in areas of low average subsurface temperatures, which makes it difficult to assess exploitable zones. To address this problem, this study quantitatively analyzes the conditions associated with the formation of geothermal springs in fault zones, and numerically investigates the implications that outflow temperature and discharge rate from geothermal springs have on the geothermal background in the subsurface. It is concluded that the temperature of geothermal springs in fault zones is mainly controlled by the recharge rate from the country rock and the hydraulic conductivity in the fault damage zone. Importantly, the topography of the fault trace on the land surface plays an important role in determining the thermal temperature. In fault zones with a permeability higher than 1 mD and a lateral recharge rate from the country rock higher than 1 m3/day, convection plays a dominant role in the heat transport rather than thermal conduction. The geothermal springs do not necessarily occur in the place having an abnormal geothermal background (with the temperature at certain depth exceeding the temperature inferred by the global average continental geothermal gradient of 30 °C/km). Assuming a constant temperature (90 °C here, to represent a normal geothermal background in the subsurface at a depth of 3,000 m), the conditions required for the occurrence of geothermal springs were quantitatively determined.

  14. Thermodynamic and economic analysis and optimization of power cycles for a medium temperature geothermal resource

    International Nuclear Information System (INIS)

    Coskun, Ahmet; Bolatturk, Ali; Kanoglu, Mehmet

    2014-01-01

    Highlights: • We conduct the thermodynamic and economic analysis of various geothermal power cycles. • The optimization process was performed to minimize the exergy losses. • Kalina cycle is a new technology compared to flash and binary cycles. • It is shown that Kalina cycle presents a viable choice for both thermodynamically and economically. - Abstract: Geothermal power generation technologies are well established and there are numerous power plants operating worldwide. Turkey is rich in geothermal resources while most resources are not exploited for power production. In this study, we consider geothermal resources in Kutahya–Simav region having geothermal water at a temperature suitable for power generation. The study is aimed to yield the method of the most effective use of the geothermal resource and a rational thermodynamic and economic comparison of various cycles for a given resource. The cycles considered include double-flash, binary, combined flash/binary, and Kalina cycle. The selected cycles are optimized for the turbine inlet pressure that would generate maximum power output and energy and exergy efficiencies. The distribution of exergy in plant components and processes are shown using tables. Maximum first law efficiencies vary between 6.9% and 10.6% while the second law efficiencies vary between 38.5% and 59.3% depending on the cycle considered. The maximum power output, the first law, and the second law efficiencies are obtained for Kalina cycle followed by combined cycle and binary cycle. An economic analysis of four cycles considered indicates that the cost of producing a unit amount of electricity is 0.0116 $/kW h for double flash and Kalina cycles, 0.0165 $/kW h for combined cycle and 0.0202 $/kW h for binary cycle. Consequently, the payback period is 5.8 years for double flash and Kalina cycles while it is 8.3 years for combined cycle and 9 years for binary cycle

  15. Geothermal energy

    OpenAIRE

    Manzella A.

    2017-01-01

    Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity) worldwide, usually requires geothermal resources temperatures of over 100 °C. Fo...

  16. Recovery Act: High-Temperature Circuit Boards for use in Geothermal Well Monitoring Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hooker, Matthew [Composite Tehcnology Development, Inc., Lafayette, CO (United States); Fabian, Paul [Composite Tehcnology Development, Inc., Lafayette, CO (United States)

    2013-05-01

    The U.S. Department of Energy is leading the development of alternative energy sources that will ensure the long-term energy independence of our nation. One of the key renewable resources currently being advanced is geothermal energy. To tap into the large potential offered by generating power from the heat of the earth, and for geothermal energy to be more widely used, it will be necessary to drill deeper wells to reach the hot, dry rock located up to 10 km beneath the earth’s surface. In this instance, water will be introduced into the well to create a geothermal reservoir. A geothermal well produced in this manner is referred to as an enhanced geothermal system (EGS). EGS reservoirs are typically at depths of 3 to 10 km, and the temperatures at these depths have become a limiting factor in the application of existing downhole technologies. These high temperatures are especially problematic for electronic systems such as downhole data-logging tools, which are used to map and characterize the fractures and high-permeability regions in underground formations. Information provided by these tools is assessed so that underground formations capable of providing geothermal energy can be identified, and the subsequent drilling operations can be accurately directed to those locations. The mapping of geothermal resources involves the design and fabrication of sensor packages, including the electronic control modules, to quantify downhole conditions (300°C temperature, high pressure, seismic activity, etc.). Because of the extreme depths at which these measurements are performed, it is most desirable to perform the sensor signal processing downhole and then transmit the information to the surface. This approach necessitates the use of high-temperature electronics that can operate in the downhole environment. Downhole signal processing in EGS wells will require the development and demonstration of circuit boards that can withstand the elevated temperatures found at these

  17. Selected data for low-temperature (less than 90{sup 0}C) geothermal systems in the United States: reference data for US Geological Survey Circular 892

    Energy Technology Data Exchange (ETDEWEB)

    Reed, M.J.; Mariner, R.H.; Brook, C.A.; Sorey, M.L.

    1983-12-15

    Supporting data are presented for the 1982 low-temperature geothermal resource assessment of the United States. Data are presented for 2072 geothermal sites which are representative of 1168 low-temperature geothermal systems identified in 26 States. The low-temperature geothermal systems consist of 978 isolated hydrothermal-convection systems, 148 delineated-area hydrothermal-convection systems, and 42 delineated-area conduction-dominated systems. The basic data and estimates of reservoir conditions are presented for each geothermal system, and energy estimates are given for the accessible resource base, resource, and beneficial heat for each isolated system.

  18. Low-temperature geothermal water in Utah: A compilation of data for thermal wells and springs through 1993

    Energy Technology Data Exchange (ETDEWEB)

    Blackett, R.E.

    1994-07-01

    The Geothermal Division of DOE initiated the Low-Temperature Geothermal Resources and Technology Transfer Program, following a special appropriation by Congress in 1991, to encourage wider use of lower-temperature geothermal resources through direct-use, geothermal heat-pump, and binary-cycle power conversion technologies. The Oregon Institute of Technology (OIT), the University of Utah Research Institute (UURI), and the Idaho Water Resources Research Institute organized the federally-funded program and enlisted the help of ten western states to carry out phase one. This first phase involves updating the inventory of thermal wells and springs with the help of the participating state agencies. The state resource teams inventory thermal wells and springs, and compile relevant information on each sources. OIT and UURI cooperatively administer the program. OIT provides overall contract management while UURI provides technical direction to the state teams. Phase one of the program focuses on replacing part of GEOTHERM by building a new database of low- and moderate-temperature geothermal systems for use on personal computers. For Utah, this involved (1) identifying sources of geothermal date, (2) designing a database structure, (3) entering the new date; (4) checking for errors, inconsistencies, and duplicate records; (5) organizing the data into reporting formats; and (6) generating a map (1:750,000 scale) of Utah showing the locations and record identification numbers of thermal wells and springs.

  19. The influence of heat sink temperature on the seasonal efficiency of shallow geothermal heat pumps

    Science.gov (United States)

    Pełka, Grzegorz; Luboń, Wojciech; Sowiżdżał, Anna; Malik, Daniel

    2017-11-01

    Geothermal heat pumps, also known as ground source heat pumps (GSHP), are the most efficient heating and cooling technology utilized nowadays. In the AGH-UST Educational and Research Laboratory of Renewable Energy Sources and Energy Saving in Miękinia, shallow geothermal heat is utilized for heating. In the article, the seasonal efficiency of two geothermal heat pump systems are described during the 2014/2015 heating season, defined as the period between 1st October 2014 and 30th April 2015. The first system has 10.9 kW heating capacity (according to European Standard EN 14511 B0W35) and extracts heat from three vertical geothermal loops at a depth of 80m each. During the heating season, tests warmed up the buffer to 40°C. The second system has a 17.03 kW heating capacity and extracts heat from three vertical geothermal loops at a depth of 100 m each, and the temperature of the buffer was 50°C. During the entire heating season, the water temperatures of the buffers was constant. Seasonal performance factors were calculated, defined as the quotient of heat delivered by a heat pump to the system and the sum of electricity consumed by the compressor, source pump, sink pump and controller of heat pumps. The measurements and calculations give the following results: - The first system was supplied with 13 857 kWh/a of heat and consumed 3 388 kWh/a electricity. The SPF was 4.09 and the average temperature of outlet water from heat pump was 40.8°C, and the average temperature of brine flows into the evaporator was 3.7 °C; - The second system was supplied with 12 545 kWh/a of heat and consumed 3 874 kWh/a electricity. The SPF was 3.24 and the average temperature of outlet water from heat pump was 51.6°C, and the average temperature of brine flows into the evaporator was 5.3°C. To summarize, the data shown above presents the real SPF of the two systems. It will be significant in helping to predict the SPF of objects which will be equipped with ground source heat pumps.

  20. Potential for offshore geothermal developments using deep gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Teodoriu, C.; Falcone, G. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE

    2013-08-01

    application once the gas field has been depleted. The major risks include alternative uses of wells in no flow or rapid depletion situations. Reutilisation of the wells of depleted gas reservoirs will invariably lead to lower geothermal development costs compared with starting a geothermal campaign by drilling new wells. Additionally, the existing infrastructure like platforms, transmission lines, etc. will further reduce the investment costs for such offshore applications. It shows the advantages of low output temperature in terms of specific power output for low to moderate temperature geofluids, after Tester 2006. An increase of 10 to 25% can be achieved when lowering the output temperature. (orig.)

  1. Geothermal energy

    International Nuclear Information System (INIS)

    Kappelmeyer, O.

    1991-01-01

    Geothermal energy is the natural heat of the earth. It represents an inexhaustible source of energy. In many countries, which are mostly located within the geothermal belts of the world, geothermal energy is being used since many decades for electricity generation and direct heating applications comprising municipal, industrial and agricultural heating. Outside the geothermal anomalous volcanic regions, hot ground water from deep rock formations at temperatures above 70 o C is used for process heat and space heating. Low prices for gas and oil hinder the development of geothermal plants in areas outside positive geothermal anomalies; the cost of drilling to reach depths, where temperatures are above 50 o C to 70 o C, is high. The necessary total investment per MW th installed capacity is in the order of 5 Mio- DM/MW th (3 Mio $/MW th ). Experience shows, that an economic break even with oil is reached at an oil price of 30$ per barrel or if an adequate bonus for the clean, environmentally compatible production of geothermal heat is granted. Worldwide the installed electric capacity of geothermal power plants is approximately 6 000 MW e . About 15 000 MW th of thermal capacity is being extracted for process heat and space heat. The importance of the terrestrial heat as an energy resource would be substantially increased, if the heat, stored in the hot crystalline basement could be extracted at economical production costs. Geothermal energy is a competitive energy source in areas with high geothermal gradients (relative low cost for drilling) and would be competitive in areas with normal geothermal gradients, if a fair compensation for environmental implications from fossil and nuclear power production would be granted. (author) 2 figs., 1 tab., 6 refs

  2. High-temperature explosive development for geothermal well stimulation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, E.W.; Mars, J.E.; Wang, C.

    1978-03-31

    A two-component, temperature-resistant liquid explosive called HITEX has been developed which is capable of withstanding 561/sup 0/K (550/sup 0/F) for 24 hours in a geothermal environment. The explosive is intended for the stimulation of nonproducing or marginally producing geothermal (hot dry rock, vapor-dominated or hydrothermal) reservoirs by fracturing the strata in the vicinity of a borehole. The explosive is inherently safe because it is mixed below ground downhole from two nondetonable liquid components. Development and safety tests included differential scanning calorimetry, thermal stability, minerals compatibility, drop-weight sensitivity, adiabatic compression, electrostatic discharge sensitivity, friction sensitivity, detonation arrest capability, cook-off tests, detonability at ambient and elevated pressure, detonation velocity and thin film propagation in a wedge.

  3. GIS to support cost-effective decisions on renewable sources applications for low temperature geothermal energy

    CERN Document Server

    Gemelli, Alberto; Diamantini, Claudia; Longhi, Sauro

    2013-01-01

    Through the results of a developed case study of information system for low temperature geothermal energy, GIS to Support Cost-effective Decisions on Renewable Sources addresses the issue of the use of Geographic Information Systems (GIS) in evaluating cost-effectiveness of renewable resource exploitation regional scale. Focusing on the design of a Decision Support System, a process is presented aimed to transform geographic data into knowledge useful for analysis and decision-making on the economic exploitation of geothermal energy. This detailed description includes a literature review and technical issues related to data collection, data mining, decision analysis for the informative system developed for the case study. A multi-disciplinary approach to GIS design is presented which is also an innovative example of fusion of georeferenced data acquired from multiple sources including remote sensing, networks of sensors and socio-economic censuses. GIS to Support Cost-effective Decisions on Renewable Sources ...

  4. Combination of Well-Logging Temperature and Thermal Remote Sensing for Characterization of Geothermal Resources in Hokkaido, Northern Japan

    Directory of Open Access Journals (Sweden)

    Bingwei Tian

    2015-03-01

    Full Text Available Geothermal resources have become an increasingly important source of renewable energy for electrical power generation worldwide. Combined Three Dimension (3D Subsurface Temperature (SST and Land Surface Temperature (LST measurements are essential for accurate assessment of geothermal resources. In this study, subsurface and surface temperature distributions were combined using a dataset comprised of well logs and Thermal Infrared Remote sensing (TIR images from Hokkaido island, northern Japan. Using 28,476 temperature data points from 433 boreholes sites and a method of Kriging with External Drift or trend (KED, SST distribution model from depths of 100 to 1500 m was produced. Regional LST was estimated from 13 scenes of Landsat 8 images. Resultant SST ranged from around 50 °C to 300 °C at a depth of 1500 m. Most of western and part of the eastern Hokkaido are characterized by high temperature gradients, while low temperatures were found in the central region. Higher temperatures in shallower crust imply the western region and part of the eastern region have high geothermal potential. Moreover, several LST zones considered to have high geothermal potential were identified upon clarification of the underground heat distribution according to 3D SST. LST in these zones showed the anomalies, 3 to 9 °C higher than the surrounding areas. These results demonstrate that our combination of TIR and 3D temperature modeling using well logging and geostatistics is an efficient and promising approach to geothermal resource exploration.

  5. Low-Temperature Projects of the Department of Energy's Geothermal Technologies Program: Evaluation and Lessons Learned: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Tom; Snyder, Neil; Gosnold, Will

    2016-12-01

    This paper discusses opportunities and challenges related to the technical and economic feasibility of developing power generation from geothermal resources at temperatures of 150 degrees C and lower. Insights from projects funded by the U.S. Department of Energy (DOE), Geothermal Technologies Office inform these discussions and provide the basis for some lessons learned to help guide decisions by DOE and the industry in further developing this resource. The technical basis for low-temperature geothermal energy is well established and the systems can be economic today in certain situations. However, these applications are far from a 'plug and play' product; successful development today requires a good knowledge of geothermal system design and operation.

  6. A renewable energy scenario for Aalborg Municipality based on low-temperature geothermal heat, wind power and biomass

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg; Mathiesen, Brian Vad; Möller, Bernd

    2010-01-01

    Aalborg Municipality, Denmark, wishes to investigate the possibilities of becoming independent of fossil fuels. This article describes a scenario for supplying Aalborg Municipality’s energy needs through a combination of low-temperature geothermal heat, wind power and biomass. Of particular focus...... in the scenario is how low-temperature geothermal heat may be utilised in district heating (DH) systems. The analyses show that it is possible to cover Aalborg Municipality’s energy needs through the use of locally available sources in combination with significant electricity savings, heat savings, reductions...... in industrial fuel use and savings and fuel-substitutions in the transport sector. With biomass resources being finite, the two marginal energy resources in Aalborg are geothermal heat and wind power. If geothermal heat is utilised more, wind power may be limited and vice versa. The system still relies...

  7. Low-Temperature Projects of the Department of Energy's Geothermal Technologies Program: Evaluation and Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Tom; Snyder, Neil; Gosnold, Will

    2016-10-23

    This paper discusses opportunities and challenges related to the technical and economic feasibility of developing power generation from geothermal resources at temperatures of 150 degrees C and lower. Insights from projects funded by the U.S. Department of Energy (DOE), Geothermal Technologies Office inform these discussions and provide the basis for some lessons learned to help guide decisions by DOE and the industry in further developing this resource. The technical basis for low-temperature geothermal energy is well established and the systems can be economic today in certain situations. However, these applications are far from a 'plug and play' product; successful development today requires a good knowledge of geothermal system design and operation.

  8. THE MAXIMUM EFFECT OF DEEP LAKES ON TEMPERATURE PROFILES – DETERMINATION OF THE GEOTHERMAL GRADIENT

    OpenAIRE

    Eppelbaum L. V.; Kutasov I. M.; Balobaev V. T.

    2009-01-01

    Understanding the climate change processes on the basis of geothermal observations in boreholes is an important and at the same time high-intricate problem. Many non-climatic effects could cause changes in ground surface temperatures. In this study we investigate the effects of deep lakes on the borehole temperature profilesobserved within or in the vicinity of the lakes. We propose a method based on utilization of Laplace equation with nonuniform boundary conditions. The proposed method make...

  9. An innovative ORC power plant layout for heat and power generation from medium- to low-temperature geothermal resources

    International Nuclear Information System (INIS)

    Fiaschi, Daniele; Lifshitz, Adi; Manfrida, Giampaolo; Tempesti, Duccio

    2014-01-01

    Highlights: • Explotation of medium temperature geothermal resource with ORC–CHP is investigated. • A new CHP configuration to provide higher temperature to thermal user is proposed. • Several organic fluids and wide range of heat demand are studied. • The system produces higher power (almost 55%) in comparison to typical layouts. • Optimal working fluids vary with the characteristics of the heat demand. - Abstract: Medium temperature (up to 170 °C), water dominated geothermal resources are the most widespread in the world. The binary geothermal-ORC power plants are the most suitable energy conversion systems for this kind of resource. Specifically, combined heat and power (CHP) systems have the potential to improve the efficiency in exploiting the geothermal resources by cascading the geothermal fluid heat carrier to successively lower temperature users, thus increasing first and second law efficiency of the entire power plant. However, geothermal CHPs usually extract heat from the geofluid either in parallel or in series to the ORC, and usually provide only low temperature heat, which is seldom suitable for industrial use. In this paper, a new CHP configuration, called Cross Parallel CHP, has been proposed and analyzed. It aims to provide higher temperature heat suitable for industrial use, allowing the exploitation of geothermal resources even in areas where district heating is not needed. The proposed CHP allows the reduction of the irreversibilities in the heat exchangers and the loss to the environment related to the re-injection of geofluid, thus producing higher electric power output while satisfying, at the same time, the heat demand of the thermal utility for a wide range of temperatures and mass flow rates (80–140 °C; 3–13 kg/s). Several organic fluids are investigated and the related optimizing working conditions are found by a built in procedure making use of genetic algorithms. The results show that the optimal working fluids and

  10. Optimization of Brayton cycles for low-to-moderate grade thermal energy sources

    International Nuclear Information System (INIS)

    Rovira, Antonio; Muñoz-Antón, Javier; Montes, María José; Martínez-Val, José María

    2013-01-01

    Future electricity generation will involve low or moderate temperature technologies. In such a scenario, optimisation of thermodynamic cycles will be a key task. This work presents a systematic analysis to find the operating regime where Brayton cycles reach the highest efficiency, using real substances and given heat source and sink temperatures. Several configurations using fluids close to its critical point at the compressor inlet are considered. Irreversibility sources are carefully analysed, as well as the type of working fluid. The analysis is performed by means of a theoretical approach to obtain some trends, which are afterwards validated with real gases. Results show that the efficiency and the specific work improve if the compressor inlet is close to the critical point. Furthermore, these cycles are less sensitive to pressure drops and politropic efficiencies than those working with ideal gases. The above features are more evident when the ratio of heat source and heat sink temperatures is low. The selection of the gas becomes a fundamental issue in this quest. Critical temperature should be close to ambient temperature, low critical pressure is advisable and the R/c p factor measured at the ideal gas condition should be low to further enhance the efficiency. - Highlights: • Performance analysis of Brayton cycles with the compressor inlet close to the critical point. • Cycles are not very sensitive to pressure drops and isentropic efficiencies of the compressor. • Gas selection becomes important, regarding the critical pressure and temperature as well as the kind of fluid. • R/c p factor measured at the ideal gas condition should be as low as possible

  11. The effects of low to moderate prenatal alcohol exposure in early pregnancy on IQ in 5-year-old children

    DEFF Research Database (Denmark)

    Eriksen, H-L Falgreen; Mortensen, Erik Lykke; Kilburn, Tina R.

    2012-01-01

    Please cite this paper as: Falgreen Eriksen H, Mortensen E, Kilburn T, Underbjerg M, Bertrand J, Støvring H, Wimberley T, Grove J, Kesmodel U. The effects of low to moderate prenatal alcohol exposure in early pregnancy on IQ in 5-year-old children. BJOG 2012;119:1191-1200. Objective To examine...... the effects of low to moderate maternal alcohol consumption during early pregnancy on children's intelligence (IQ) at age 5 years. Design Prospective follow-up study. Setting Neuropsychological testing in four Danish cities 2003-2008. Population A cohort of 1628 women and their children sampled from...... the Danish National Birth Cohort. Methods Participants were sampled based on maternal alcohol consumption during pregnancy. At 5 years of age, children were tested with the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R). Parental education, maternal IQ, maternal smoking in pregnancy...

  12. Analysis of heterogeneous characteristics in a geothermal area with low permeability and high temperature

    Directory of Open Access Journals (Sweden)

    Alfonso Aragón-Aguilar

    2017-09-01

    Full Text Available An analytical methodology for reservoir characterization was applied in the central and southwestern zones of Los Humeros geothermal field (LHGF. This study involves analysis of temperature, pressure, enthalpy and permeability in wells and their distribution along the area. The wells located in the central western side of the geothermal field are productive, whereas those located at the central-eastern side are non-productive. Through temperature profiles, determined at steady state in the analyzed wells, it was observed that at bottom conditions (approximately 2300 m depth, temperatures vary between 280 and 360 °C. The temperatures are higher at the eastern side of central zone of LHGF. A review of transient pressure tests, laboratory measurements of core samples, and correlation of circulation losses during drilling suggest that permeability of the formation is low. The enthalpy behavior in productive wells shows a tendency of increase in the steam fraction. It was found that productivity behavior has inverse relation with permeability of rock formation. Further, it is observed that an imbalance exists between exploitation and recharge. It is concluded from the results that the wells located at central-eastern area have low permeability and high temperature, which indicates possibility of heat storage.

  13. Geothermic analysis of high temperature hydrothermal activities area in Western plateau of Sichuan province, China

    Science.gov (United States)

    Zhang, J.

    2016-12-01

    There is a high temperature hydrothermal activity area in the western plateau of Sichuan. More than 200 hot springs points have been found in the region, including 11 hot spring water temperature above local boiling point. Most of these distribute along Jinshajjiang fracture, Dege-Xiangcheng fracture, Ganzi-Litang fracture as well as Xianshuihe fracture, and form three high-temperature hydrothermal activity strips in the NW-SE direction. Using gravity, magnetic, seismic and helium isotope data, this paper analyzed the crust-mantle heat flow structure, crustal heat source distribution and water heating system. The results show that the geothermal activity mainly controlled by the "hot" crust. The ratio of crustal heat flow and surface heat flow is higher than 60%. In the high temperature hydrothermal activities area, there is lower S wave velocity zone with VsGeothermal water mainly reserve in the Triassic strata of the containing water good carbonate rocks, and in the intrusive granite which is along the fault zone. The thermal energy of Surface heat thermal activities mainly comes from the high-temperature hot source which is located in the middle and lower crust. Being in the deep crustal fracture, the groundwater infiltrated to the deep crust and absorbed heat, then, quickly got back to the surface and formed high hot springs.

  14. Humboldt's spa: microbial diversity is controlled by temperature in geothermal environments.

    Science.gov (United States)

    Sharp, Christine E; Brady, Allyson L; Sharp, Glen H; Grasby, Stephen E; Stott, Matthew B; Dunfield, Peter F

    2014-06-01

    Over 200 years ago Alexander von Humboldt (1808) observed that plant and animal diversity peaks at tropical latitudes and decreases toward the poles, a trend he attributed to more favorable temperatures in the tropics. Studies to date suggest that this temperature-diversity gradient is weak or nonexistent for Bacteria and Archaea. To test the impacts of temperature as well as pH on bacterial and archaeal diversity, we performed pyrotag sequencing of 16S rRNA genes retrieved from 165 soil, sediment and biomat samples of 36 geothermal areas in Canada and New Zealand, covering a temperature range of 7.5-99 °C and a pH range of 1.8-9.0. This represents the widest ranges of temperature and pH yet examined in a single microbial diversity study. Species richness and diversity indices were strongly correlated to temperature, with R(2) values up to 0.62 for neutral-alkaline springs. The distributions were unimodal, with peak diversity at 24 °C and decreasing diversity at higher and lower temperature extremes. There was also a significant pH effect on diversity; however, in contrast to previous studies of soil microbial diversity, pH explained less of the variability (13-20%) than temperature in the geothermal samples. No correlation was observed between diversity values and latitude from the equator, and we therefore infer a direct temperature effect in our data set. These results demonstrate that temperature exerts a strong control on microbial diversity when considered over most of the temperature range within which life is possible.

  15. High-Temperature Self-Healing and Re-Adhering Geothermal Well Cement Composites

    Science.gov (United States)

    Pyatina, T.; Sugama, T.; Boodhan, Y.; Nazarov, L.

    2017-12-01

    Self-healing cementitious materials are particularly attractive for the cases where damaged areas are difficult to locate and reach. High-temperature geothermal wells with aggressive environments impose most difficult conditions on cements that must ensure durable zonal isolation under repeated thermal, chemical and mechanical stresses. The present work evaluates matrix and carbon steel (CS) - cement interface self-healing and re-adhering properties of various inorganic cementitious composites under steam, alkali carbonate or brine environments at 270-300oC applicable to geothermal wells. The composite materials included blends based on Ordinary Portland Cement (OPC) and natural zeolites and alkali or phosphate activated composites of Calcium Aluminate Cement (CAC) with fly ash, class F. Class G cement blend with crystalline silica was used as a baseline. Compressive-strength and bond-strength recoveries were examined to evaluate self-healing and re-adhering properties of the composites after repeated crush tests followed by 5-day healing periods in these environments. The optical and scanning electron microscopes, X-ray diffraction, Fourier Transform infrared, Raman spectroscopy and EDX measurements were used to identify phases participating in the strengths recoveries and cracks filling processes. Amorphous silica-rich- and small-size crystalline phases played an important role in the healing of the tested composites in all environments. Possible ways to enhance self-healing properties of cementitious composites under conditions of geothermal wells were identified.

  16. Utilization of low temperature geothermal water in traditional and advanced agricultural applications

    International Nuclear Information System (INIS)

    Rossi, L.; Pacciaroni, F.

    1992-01-01

    The locations of large amounts of low temperature geothermal sources (30 to 80 degrees C) have been identified in Italy and in many European countries; one of the most interesting utilization of these sources is greenhouse heating. Surplus investment in comparison with conventional heating systems is justified only by the application of low cost technologies for well completion, heating distribution and waste heat treatment. In the last few years, many efforts have been made in the development of these technologies and selection of more profitable crops. Since 1984, ENEA (Italian Agency for Energy, New Technologies and the Environment) has carried out experimental work in two geothermal stations located in Canino (VT) and in Gorgo di Latisana (UD). In these plants, a number of greenhouses enveloped with plastic film are provided with different heating systems; the combination of soil and forced air heating is preferred. Plastic pipes, buried in the soil, are used as soil heating for horticulture and fruit production. For plot plant cultivation, soil heating is obtained by plastic pipes half-buried in a concrete floor. Asparagus cultivation is carried out with buried pipes. No additional heating with conventional fuel is provided in any greenhouse. During these years, ENEA has developed heating and water distribution technologies: current industrial components are generally utilized. Moreover, ENEA has recently completed an advanced automatic control system able to control geothermal greenhouses, manage water distribution, save energy and optimize environmental conditions

  17. Economic study of low temperature geothermal energy in Lassen and Modoc counties, California

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-04-01

    The purpose of this study was to investigate the feasibility of using low cost, low temperature geothermal energy in job-producing industries to increase employment and encourage economic development. The study, encompassing all of Lassen and modoc Counties, was to be site-specific, referencing candidate geothermal applications to known hot wells and springs as previously determined, or to new wells with specific characteristics as defined in the Scope of Work. The emphasis was to be placed on economically practical and readily achievable applications from known resources, thus complimenting the recently completed ERDA-Susanville Study where a designated community was used as a ''laboratory'' in which land-use planning, institutional aspects, geological assessments, technical modeling and socioeconomic impacts were all examined in overview. During the course of the study, monthly progress reports were prepared and reviewed with the Commission so that emphasis on particular features of study could be changed as necessary to reflect updated findings and to redirect efforts into additional areas of potential promise as they became apparent. In this manner, a degree of flexibility was maintained which allowed a more comprehensive study than would have been otherwise possible. Although the report generates both positive and negative findings in specific areas of investigation, it is felt that the overall long term prognosis for geothermal energy stimulus to industry in the area is excellent.

  18. Utilization of low temperature geothermal water in traditional and advanced agricultural applications

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, L.; Pacciaroni, F.

    1992-12-31

    The locations of large amounts of low temperature geothermal sources (30 to 80 degrees C) have been identified in Italy and in many European countries; one of the most interesting utilization of these sources is greenhouse heating. Surplus investment in comparison with conventional heating systems is justified only by the application of low cost technologies for well completion, heating distribution and waste heat treatment. In the last few years, many efforts have been made in the development of these technologies and selection of more profitable crops. Since 1984, ENEA (Italian Agency for Energy, New Technologies and the Environment) has carried out experimental work in two geothermal stations located in Canino (VT) and in Gorgo di Latisana (UD). In these plants, a number of greenhouses enveloped with plastic film are provided with different heating systems; the combination of soil and forced air heating is preferred. Plastic pipes, buried in the soil, are used as soil heating for horticulture and fruit production. For plot plant cultivation, soil heating is obtained by plastic pipes half-buried in a concrete floor. Asparagus cultivation is carried out with buried pipes. No additional heating with conventional fuel is provided in any greenhouse. During these years, ENEA has developed heating and water distribution technologies: current industrial components are generally utilized. Moreover, ENEA has recently completed an advanced automatic control system able to control geothermal greenhouses, manage water distribution, save energy and optimize environmental conditions.

  19. Geothermal regime of Tarim basin, NW China: insights from borehole temperature logging

    Science.gov (United States)

    Liu, S.; Lei, X.

    2013-12-01

    Geothermal regime of sedimentary basin is vital for understanding basin (de)formation process, hydrocarbon generation status and assessing the resource potential. Located at the Precambrian craton block, the Tarim basin is the largest intermountain basin in China, which is also the ongoing target of oil and gas exploration. Previous knowledge of thermal regime of this basin is from limited oil exploration borehole testing temperature, the inherent deficiency of data of this type makes accurate understanding of its thermal regime impossible. Here we reported our latest steady temperature logging results in this basin and analyze its thermal regime as well. In this study, 10 temperature loggings are conducted in the northern Tarim basin where the major oil and gas fields are discovered. All the boreholes for temperature logging are non-production wells and are shut in at least more than 2~3 years, ensuring the temperature equilibrium after drilling. The derived geothermal gradient varies from 20.2 to 26.1 degree/km, with a mean of 22.0 degree/km. However, some previous reported gradients in this area are obviously lower than our results; for example, the previous gradient of THN2 well is 13.2 degree/km but 23.2 degree/km in this study, and not enough equilibrium time in previous logging accounts for this discrepancy. More important, it is found that high gradients usually occur in the gas field and the gradients of the gas fields are larger than those in other oil fields, indicating higher thermal regime in gas field. The cause of this phenomenon is unclear, and the upward migration of hot fluid along fault conduit is speculated as the possible mechanism for this high geothermal anomaly in the oil and gas fields. Combined with measured thermal conductivity data, 10 new heat flow values are also achieved, and the heat flow of the Tarim basin is between 38mW/m2 and 52mW/m2, with a mean of 43 mW/m2. This relatively low heat flow is coincident with that of typical

  20. Performance analysis of low temperature heat source of organic Rankine cycle for geothermal application

    Science.gov (United States)

    Pintoro, A.; Ambarita, H.; Nur, T. B.; Napitupulu, F. H.

    2018-02-01

    Indonesia has a high potential energy resources from geothermal activities. Base on the report of Asian Development Bank and World Bank, the estimated of Indonesian hydrothermal geothermal resource considered to be the largest among the world. If it’s can be utilized to produce the electric power, it’s can contribute to increasing the electrification rates in Indonesia. In this study, an experimental studied of electric power generation, utilizing the Organic Rankine Cycle (ORC) system to convert the low level heat of hydrothermal as an energy source. The temperature of hydrothermal was modelled as hot water from water boiler which has a temperature range from 60 °C - 100 °C to heat up the organic working fluid of ORC system. The system can generated 1,337.7 watts of electricity when operated using R134A with hot water inlet temperature of 100 °C. Changing system working fluid to R245fa, the net power obtained increase to 1,908.9 watts with the same heat source condition. This study showed that the ORC system can be implemented to utilize low temperature heat source of hydrothermal in Indonesia.

  1. Optimization of the exploitation system of a low enthalpy geothermal aquifer with zones of different transmissivities and temperatures

    International Nuclear Information System (INIS)

    Tselepidou, K.; Katsifarakis, K.L.

    2010-01-01

    Market penetration of renewable energy sources, such as geothermal energy, could be promoted even by small cost reductions, achieved through improved development design. This paper deals with optimization of the exploitation system of a low enthalpy geothermal aquifer, by means of the method of genetic algorithms, which has been successfully used in similar problems of groundwater resources management. With respect to water flow, the aquifer consists of two zones of different transmissivities, while from the thermal point of view it may bear any number of zones with different temperatures. The optimization process comprises the annual pumping cost of the required flow and the amortization cost of the pipe network, which carries the hot water from the wells to a central water tank, situated at the border of the geothermal field. Results show that application of the proposed methodology allows better planning of low enthalpy geothermal heating systems, which may be crucial in cases of marginal financial viability. (author)

  2. Rapid high temperature field test method for evaluation of geothermal calcite scale inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, R.G.

    1982-08-01

    A test method is described which allows the rapid field testing of calcite scale inhibitors in high- temperature geothermal brines. Five commercial formulations, chosen on the basis of laboratory screening tests, were tested in brines with low total dissolved solids at ca 500 F. Four were found to be effective; of these, 2 were found to be capable of removing recently deposited scale. One chemical was tested in the full-flow brine line for 6 wks. It was shown to stop a severe surface scaling problem at the well's control valve, thus proving the viability of the rapid test method. (12 refs.)

  3. Selection of working fluids for a novel low-temperature geothermally-powered ORC based cogeneration system

    International Nuclear Information System (INIS)

    Guo, T.; Wang, H.X.; Zhang, S.J.

    2011-01-01

    Highlights: → Performances of a novel cogeneration system using low-temperature geothermal sources under disturbance conditions were investigated. → It aimed at identifying appropriate fluids yielding high PPR and QQR values. → Fluids group presenting higher normal boiling point values showed averagely 7.7% higher PPR with a larger variation than QQR values under disturbance conditions. → Smaller T P value, higher η t value, higher geothermal source parameters and lower heating supply parameters led to higher PPR values but lower QQR values. -- Abstract: A novel cogeneration system driven by low-temperature geothermal sources was investigated in this study. This system consists of a low-temperature geothermally-powered organic Rankine cycle (ORC) subsystem, an intermediate heat exchanger and a commercial R134a-based heat pump subsystem. The main purpose is to identify appropriate fluids which may yield high PPR (the ratio of power produced by the power generation subsystem to power consumed by the heat pump subsystem) value and QQR (the ratio of heat supplied to the user to heat produced by the geothermal source) value. Performances of the novel cogeneration system under disturbance conditions have also been studied. Results indicate that fluids group presenting higher normal boiling point values shows averagely 7.7% higher PPR values and R236ea and R245ca outstand among the group. ΔT P (pinch temperature difference in heat exchangers) and η t (turbine efficiency) values play more important roles on the variation of PPR values. QQR values change slightly with various ΔT P , η t and η rp (refrigerant pump efficiency) values while the variation range is larger under various geothermal source and heating supply parameters. Smaller ΔT P value, higher η t value, higher geothermal source parameters and lower heating supply parameters lead to higher PPR values but lower QQR values.

  4. STATIC{sub T}EMP: a useful computer code for calculating static formation temperatures in geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Santoyo, E. [Universidad Nacional Autonoma de Mexico, Centro de Investigacion en Energia, Temixco (Mexico); Garcia, A.; Santoyo, S. [Unidad Geotermia, Inst. de Investigaciones Electricas, Temixco (Mexico); Espinosa, G. [Universidad Autonoma Metropolitana, Co. Vicentina (Mexico); Hernandez, I. [ITESM, Centro de Sistemas de Manufactura, Monterrey (Mexico)

    2000-07-01

    The development and application of the computer code STATIC{sub T}EMP, a useful tool for calculating static formation temperatures from actual bottomhole temperature data logged in geothermal wells is described. STATIC{sub T}EMP is based on five analytical methods which are the most frequently used in the geothermal industry. Conductive and convective heat flow models (radial, spherical/radial and cylindrical/radial) were selected. The computer code is a useful tool that can be reliably used in situ to determine static formation temperatures before or during the completion stages of geothermal wells (drilling and cementing). Shut-in time and bottomhole temperature measurements logged during well completion activities are required as input data. Output results can include up to seven computations of the static formation temperature by each wellbore temperature data set analysed. STATIC{sub T}EMP was written in Fortran-77 Microsoft language for MS-DOS environment using structured programming techniques. It runs on most IBM compatible personal computers. The source code and its computational architecture as well as the input and output files are described in detail. Validation and application examples on the use of this computer code with wellbore temperature data (obtained from specialised literature) and with actual bottomhole temperature data (taken from completion operations of some geothermal wells) are also presented. (Author)

  5. Design and optimization of organic rankine cycle for low temperature geothermal power plant

    Science.gov (United States)

    Barse, Kirtipal A.

    Rising oil prices and environmental concerns have increased attention to renewable energy. Geothermal energy is a very attractive source of renewable energy. Although low temperature resources (90°C to 150°C) are the most common and most abundant source of geothermal energy, they were not considered economical and technologically feasible for commercial power generation. Organic Rankine Cycle (ORC) technology makes it feasible to use low temperature resources to generate power by using low boiling temperature organic liquids. The first hypothesis for this research is that using ORC is technologically and economically feasible to generate electricity from low temperature geothermal resources. The second hypothesis for this research is redesigning the ORC system for the given resource condition will improve efficiency along with improving economics. ORC model was developed using process simulator and validated with the data obtained from Chena Hot Springs, Alaska. A correlation was observed between the critical temperature of the working fluid and the efficiency for the cycle. Exergy analysis of the cycle revealed that the highest exergy destruction occurs in evaporator followed by condenser, turbine and working fluid pump for the base case scenarios. Performance of ORC was studied using twelve working fluids in base, Internal Heat Exchanger and turbine bleeding constrained and non-constrained configurations. R601a, R245ca, R600 showed highest first and second law efficiency in the non-constrained IHX configuration. The highest net power was observed for R245ca, R601a and R601 working fluids in the non-constrained base configuration. Combined heat exchanger area and size parameter of the turbine showed an increasing trend as the critical temperature of the working fluid decreased. The lowest levelized cost of electricity was observed for R245ca followed by R601a, R236ea in non-constrained base configuration. The next best candidates in terms of LCOE were R601a, R

  6. Scale Resistant Heat Exchanger for Low Temperature Geothermal Binary Cycle Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hays, Lance G. [Energent Corporation, Santa Ana, CA (United States)

    2014-11-18

    Phase 1 of the investigation of improvements to low temperature geothermal power systems was completed. The improvements considered were reduction of scaling in heat exchangers and a hermetic turbine generator (eliminating seals, seal system, gearbox, and lube oil system). A scaling test system with several experiments was designed and operated at Coso geothermal resource with brine having a high scaling potential. Several methods were investigated at the brine temperature of 235 ºF. One method, circulation of abradable balls through the brine passages, was found to substantially reduce scale deposits. The test heat exchanger was operated with brine outlet temperatures as low as 125 ºF, which enables increased heat input available to power conversion systems. For advanced low temperature cycles, such as the Variable Phase Cycle (VPC) or Kalina Cycle, the lower brine temperature will result in a 20-30% increase in power production from low temperature resources. A preliminary design of an abradable ball system (ABS) was done for the heat exchanger of the 1 megawatt VPC system at Coso resource. The ABS will be installed and demonstrated in Phase 2 of this project, increasing the power production above that possible with the present 175 ºF brine outlet limit. A hermetic turbine generator (TGH) was designed and manufacturing drawings produced. This unit will use the working fluid (R134a) to lubricate the bearings and cool the generator. The 200 kW turbine directly drives the generator, eliminating a gearbox and lube oil system. Elimination of external seals eliminates the potential of leakage of the refrigerant or hydrocarbon working fluids, resulting in environmental improvement. A similar design has been demonstrated by Energent in an ORC waste heat recovery system. The existing VPC power plant at Coso was modified to enable the “piggyback” demonstration of the TGH. The existing heat exchanger, pumps, and condenser will be operated to provide the required

  7. The impact of temperature on microbial diversity and AOA activity in the Tengchong Geothermal Field, China

    Science.gov (United States)

    Li, Haizhou; Yang, Qunhui; Li, Jian; Gao, Hang; Li, Ping; Zhou, Huaiyang

    2015-11-01

    Using a culture-independent method that combines CARD-FISH, qPCR and 16S rDNA, we investigated the abundance, community structure and diversity of microbes along a steep thermal gradient (50-90 °C) in the Tengchong Geothermal Field. We found that Bacteria and Archaea abundance changed markedly with temperature changes and that the number of cells was lowest at high temperatures (90.8 °C). Under low-temperature conditions (52.3-74.6 °C), the microbial communities were dominated by Bacteria, which accounted for 60-80% of the total number of cells. At 74.6 °C, Archaea were dominant, and at 90.8 °C, they accounted for more than 90% of the total number of cells. Additionally, the microbial communities at high temperatures (74.6-90.8 °C) were substantially simpler than those at the low-temperature sites. Only a few genera (e.g., bacterial Caldisericum, Thermotoga and Thermoanaerobacter, archaeal Vulcanisaeta and Hyperthermus) often dominated in high-temperature environments. Additionally, a positive correlation between Ammonia-Oxidizing Archaea (AOA) activity and temperature was detected. AOA activity increased from 17 to 52 pmol of NO2- per cell d-1 with a temperature change from 50 to 70 °C.

  8. The impact of temperature on microbial diversity and AOA activity in the Tengchong Geothermal Field, China.

    Science.gov (United States)

    Li, Haizhou; Yang, Qunhui; Li, Jian; Gao, Hang; Li, Ping; Zhou, Huaiyang

    2015-11-26

    Using a culture-independent method that combines CARD-FISH, qPCR and 16S rDNA, we investigated the abundance, community structure and diversity of microbes along a steep thermal gradient (50-90 °C) in the Tengchong Geothermal Field. We found that Bacteria and Archaea abundance changed markedly with temperature changes and that the number of cells was lowest at high temperatures (90.8 °C). Under low-temperature conditions (52.3-74.6 °C), the microbial communities were dominated by Bacteria, which accounted for 60-80% of the total number of cells. At 74.6 °C, Archaea were dominant, and at 90.8 °C, they accounted for more than 90% of the total number of cells. Additionally, the microbial communities at high temperatures (74.6-90.8 °C) were substantially simpler than those at the low-temperature sites. Only a few genera (e.g., bacterial Caldisericum, Thermotoga and Thermoanaerobacter, archaeal Vulcanisaeta and Hyperthermus) often dominated in high-temperature environments. Additionally, a positive correlation between Ammonia-Oxidizing Archaea (AOA) activity and temperature was detected. AOA activity increased from 17 to 52 pmol of NO2(-) per cell d(-1) with a temperature change from 50 to 70 °C.

  9. Heat Exchangers for Utilization of the Heat of High-Temperature Geothermal Brines

    Science.gov (United States)

    Alkhasov, A. B.; Alkhasova, D. A.

    2018-03-01

    The basic component of two-circuit geothermal systems is the heat exchanger. When used in geothermal power systems, conventional shell-and-tube and plate heat exchangers cause problems related to the cleaning of the latter from salt-deposition and corrosion products. Their lifetime does not exceed, as a rule, 1 year. To utilize the heat of high-temperature geothermal brines, a heat exchanger of the "tube-in-tube" type is proposed. A heat exchanger of this design has been operated for several years in Ternair geothermal steam field; in this heat exchanger, the thermal potential of the saline thermal water is transferred to the fresh water of the secondary circuit of the heating system for apartment houses. The reduction in the weight and size characteristics of the heat exchangers is a topical problem that can be solved with the help of heat transfer enhancers. To enhance the heat transfer process in the heat exchanger, longitudinal ribbing of the heat exchange surface is proposed. The increase in the heat exchange surface from the heat carrier side by ribbing results in an increase in the amount of the heat transferred from the heating agent. The heat exchanger is easy to manufacture and is assembled out of components comprised of two concentrically positioned tubes of a definite length, 3-6 m, serially connected with each other. The method for calculation of the impact of the number and the size of the longitudinal ribs on the heat transfer in the well heat exchanger is presented and a criterion for the selection of the optimal number and design parameters of the ribs is formulated. To prevent the corrosion and salt deposition in the heat exchanger, the use of an effective OEDFK (oxyethylidenediphosphonic acid) agent is proposed. This agent has a long-lasting corrosion-inhibiting and antiscaling effect, which is explained by the formation of a strongly adhesive chelate layer difficult to wash off the surface. The passivating OEDFK layer is restored by periodical

  10. Hydrochemistry and geothermometrical modeling of low-temperature Panticosa geothermal system (Spain)

    Science.gov (United States)

    Asta, Maria P.; Gimeno, Maria J.; Auqué, Luis F.; Gómez, Javier; Acero, Patricia; Lapuente, Pilar

    2012-08-01

    The chemical characteristics of the low-temperature geothermal system of Panticosa (Spain) were investigated in order to determine the water temperature at the reservoir and to identify the main geochemical processes that affect the water composition during the ascent of the thermal waters. In general, the studied waters are similar to other geothermal systems in the Pyrenees, belonging to the group of granite-related alkaline thermal waters (high pH, low total dissolved solids, very low magnesium concentration, and sodium as the dominant cation). According to the alkaline pH of these waters, they have a very low CO2 partial pressure, bicarbonate is the dominant anion and silica is partially ionized as H3SiO4-. The unusually active acid-base pairs (HCO3-/CO32 - and, mainly, H4SiO4/H3SiO4-) act as homogeneous pH buffers and contribute to the total alkalinity in these alkaline waters. On the basis of the study of the conservative elements, a mixing process between a hot and a cold end-member has been identified. Additionally, in order to determinate the water temperature at the reservoir, several geothermometric techniques have been applied, including both geothermometrical modeling and classical geothermometrical calculations. The geothermometrical modeling seems to indicate that thermal waters re-equilibrate with respect to calcite and kaolinite during their ascent to the surface. Modeling results suggest that these thermal waters would be in equilibrium with respect to albite, K-feldspar, quartz, calcite, kaolinite and zoisite at a similar temperature of 90 ± 20 °C in the reservoir, which is in good agreement with the results obtained by applying the classical geothermometers.

  11. Geothermal energy

    Directory of Open Access Journals (Sweden)

    Manzella A.

    2017-01-01

    Full Text Available Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity worldwide, usually requires geothermal resources temperatures of over 100 °C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology, spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Produced geothermal heat in the world accounts to 164.6 TWh, with a capacity of 70.9 GW. Geothermal technology, which has focused for decades on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth’s crust.

  12. Geothermal energy

    Science.gov (United States)

    Manzella, A.

    2017-07-01

    Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG) emissions. Geothermal energy is the thermal energy stored in the underground, including any contained fluid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity) worldwide, usually requires geothermal resources temperatures of over 100 °C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology), spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Produced geothermal heat in the world accounts to 164.6 TWh, with a capacity of 70.9 GW. Geothermal technology, which has focused for decades on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth's crust.

  13. The Hengill geothermal area, Iceland: variation of temperature gradients deduced from the maximum depth of seismogenesis

    Science.gov (United States)

    Foulger, G.R.

    1995-01-01

    Given a uniform lithology and strain rate and a full seismic data set, the maximum depth of earthquakes may be viewed to a first order as an isotherm. These conditions are approached at the Hengill geothermal area, S. Iceland, a dominantly basaltic area. The temperature at which seismic failure ceases for the strain rates likely at the Hengill geothermal area is determined by analogy with oceanic crust, and is about 650 ?? 50??C. The topographies of the top and bottom of the seismogenic layer were mapped using 617 earthquakes. The thickness of the seismogenic layer is roughly constant and about 3 km. A shallow, aseismic, low-velocity volume within the spreading plate boundary that crosses the area occurs above the top of the seismogenic layer and is interpreted as an isolated body of partial melt. The base of the seismogenic layer has a maximum depth of about 6.5 km beneath the spreading axis and deepens to about 7 km beneath a transform zone in the south of the area. -from Author

  14. Geothermal data-base study: mine-water temperatures. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, D.C.; Sonderegger, J.L.

    1978-07-01

    Investigation of about 1,600 mines and prospects for perennial discharge resulted in the measurement of temperature, pH, specific conductance, and discharge at 80 sites to provide information for a geothermal data base. Measurements were made in the fall, winter, and late spring or early summer to provide information about seasonal variability. None of the temperatures measured exceeded the mean annual air temperature by 15/sup 0/F, but three areas were noted where discharges were anomalously warm, based upon high temperatures, slight temperature variation, and quantity of discharge. The most promising area, at the Gold Bug mine in the Little Rockies, discharges water averaging 7.3/sup 0/C (12.1/sup 0/F) above the mean annual air temperature. The discharge may represent water heated during circulation within the syenite intrusive body. If the syenite is enriched in uranium and thorium, an abnormal amount of heat would be produced by radioactive decay. Alternatively, the water may move through deep permeable sedimentary strata, such as the Madison Group, and be discharged to the surface through fractures in the pluton.

  15. Oxidative stress, telomere shortening, and DNA methylation in relation to low-to-moderate occupational exposure to welding fumes.

    Science.gov (United States)

    Li, Huiqi; Hedmer, Maria; Wojdacz, Tomasz; Hossain, Mohammad Bakhtiar; Lindh, Christian H; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

    2015-10-01

    Evidence suggests that exposure to welding fumes is a risk factor for lung cancer. We examined relationships between low-to-moderate occupational exposure to particles from welding fumes and cancer-related biomarkers for oxidative stress, changes in telomere length, and alterations in DNA methylation. We enrolled 101 welders and 127 controls (all currently nonsmoking men) from southern Sweden. We performed personal sampling of respirable dust and measured 8-oxodG concentrations in urine using a simplified liquid chromatography tandem mass spectrometry method. Telomere length in peripheral blood was measured by quantitative polymerase chain reaction. Methylation status of 10 tumor suppressor genes was determined by methylation-sensitive high-resolution melting analysis. All analyses were adjusted for age, body mass index, previous smoking, passive smoking, current residence, and wood burning stove/boiler at home. Welders were exposed to respirable dust at 1.2 mg/m(3) (standard deviation, 3.3 mg/m(3); range, 0.1-19.3), whereas control exposures did not exceed 0.1 mg/m(3) (P < 0.001). Welders and controls did not differ in 8-oxodG levels (β = 1.2, P = 0.17) or relative telomere length (β = -0.053, P = 0.083) in adjusted models. Welders showed higher probability of adenomatous polyposis coli (APC) methylation in the unadjusted model (odds ratio = 14, P = 0.014), but this was not significant in the fully adjusted model (P = 0.052). Every working year as a welder was associated with 0.0066 units shorter telomeres (95% confidence interval -0.013 to -0.00053, P = 0.033). Although there were no clear associations between concentrations of respirable dust and the biomarkers, there were modest signs of associations between oxidative stress, telomere alterations, DNA methylation, and occupational exposure to low-to-moderate levels of particles. © 2015 Wiley Periodicals, Inc.

  16. Assessment of the geothermal/geopressure potential of the Gulf Coastal Plan of Alabama. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.V.; Wang, G.C.; Mancini, E.A.; Benson, D.J.

    1980-01-01

    Geothermal and geopressure as well as geologic and geophysical data were studied to evaluate the potential for future development of geothermal resources underlying the Alabama Coastal Plain. Wire-line log data compiled and interpreted from more than 1300 oil and gas test wells included maximum recorded temperatures, mud weights, rock resistivities as related to geopressure, formation tops, fault locations, and depths to basement rock. The Alabama Coastal Plain area is underlain by a conduction dominated, deep sedimentary basin where geothermal gradients are low to moderate (1.0 to 1.8/sup 0/F/100 feet). In some areas of southwest Alabama, abnormally high temperatures are found in association with geopressured zones within the Haynesville Formation of Jurassic age; however, rocks of poor reservoir quality dominate this formation, with the exception of a 200-square-mile area centered in southernmost Clarke County where a porous and permeable sand unit is encased within massive salt deposits of the lower Haynesville. The results of a petrograhic study of the Smackover Formation, which underlies the Haynesville, indicate that this carbonate rock unit has sufficient porosity in some areas to be considered a potential geothermal reservoir. Future development of geothermal resources in south Alabama will be restricted to low or moderate temperature, non-electric applications, which constitute a significant potential energy source for applications in space heating and cooling and certain agricultural and industrial processes.

  17. Geophysical Methods for Monitoring Temperature Changes in Shallow Low Enthalpy Geothermal Systems

    Directory of Open Access Journals (Sweden)

    Thomas Hermans

    2014-08-01

    Full Text Available Low enthalpy geothermal systems exploited with ground source heat pumps or groundwater heat pumps present many advantages within the context of sustainable energy use. Designing, monitoring and controlling such systems requires the measurement of spatially distributed temperature fields and the knowledge of the parameters governing groundwater flow (permeability and specific storage and heat transport (thermal conductivity and volumetric thermal capacity. Such data are often scarce or not available. In recent years, the ability of electrical resistivity tomography (ERT, self-potential method (SP and distributed temperature sensing (DTS to monitor spatially and temporally temperature changes in the subsurface has been investigated. We review the recent advances in using these three methods for this type of shallow applications. A special focus is made regarding the petrophysical relationships and on underlying assumptions generally needed for a quantitative interpretation of these geophysical data. We show that those geophysical methods are mature to be used within the context of temperature monitoring and that a combination of them may be the best choice regarding control and validation issues.

  18. Nanosensors as Reservoir Engineering Tools to Map Insitu Temperature Distributions in Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Morgan Ames

    2011-06-15

    The feasibility of using nanosensors to measure temperature distribution and predict thermal breakthrough in geothermal reservoirs is addressed in this report. Four candidate sensors were identified: melting tin-bismuth alloy nanoparticles, silica nanoparticles with covalently-attached dye, hollow silica nanoparticles with encapsulated dye and impermeable melting shells, and dye-polymer composite time-temperature indicators. Four main challenges associated with the successful implementation of temperature nanosensors were identified: nanoparticle mobility in porous and fractured media, the collection and detection of nanoparticles at the production well, engineering temperature sensing mechanisms that are both detectable and irreversible, and inferring the spatial geolocation of temperature measurements in order to map temperature distribution. Initial experiments were carried out to investigate each of these challenges. It was demonstrated in a slim-tube injection experiment that it is possible to transport silica nanoparticles over large distances through porous media. The feasibility of magnetic collection of nanoparticles from produced fluid was evaluated experimentally, and it was estimated that 3% of the injected nanoparticles were recovered in a prototype magnetic collection device. An analysis technique was tailored to nanosensors with a dye-release mechanism to estimate temperature measurement geolocation by analyzing the return curve of the released dye. This technique was used in a hypothetical example problem, and good estimates of geolocation were achieved. Tin-bismuth alloy nanoparticles were synthesized using a sonochemical method, and a bench heating experiment was performed using these nanoparticles. Particle growth due to melting was observed, indicating that tin-bismuth nanoparticles have potential as temperature nanosensors

  19. Evaluation of low-temperature geothermal potential in Cache Valley, Utah. Report of investigation No. 174

    Energy Technology Data Exchange (ETDEWEB)

    de Vries, J.L.

    1982-11-01

    Field work consisted of locating 90 wells and springs throughout the study area, collecting water samples for later laboratory analyses, and field measurement of pH, temperature, bicarbonate alkalinity, and electrical conductivity. Na/sup +/, K/sup +/, Ca/sup +2/, Mg/sup +2/, SiO/sub 2/, Fe, SO/sub 4//sup -2/, Cl/sup -/, F/sup -/, and total dissolved solids were determined in the laboratory. Temperature profiles were measured in 12 additional, unused walls. Thermal gradients calculated from the profiles were approximately the same as the average for the Basin and Range province, about 35/sup 0/C/km. One well produced a gradient of 297/sup 0/C/km, most probably as a result of a near-surface occurrence of warm water. Possible warm water reservoir temperatures were calculated using both the silica and the Na-K-Ca geothermometers, with the results averaging about 50 to 100/sup 0/C. If mixing calculations were applied, taking into account the temperatures and silica contents of both warm springs or wells and the cold groundwater, reservoir temperatures up to about 200/sup 0/C were indicated. Considering measured surface water temperatures, calculated reservoir temperatures, thermal gradients, and the local geology, most of the Cache Valley, Utah area is unsuited for geothermal development. However, the areas of North Logan, Benson, and Trenton were found to have anomalously warm groundwater in comparison to the background temperature of 13.0/sup 0/C for the study area. The warm water has potential for isolated energy development but is not warm enough for major commercial development.

  20. Exploration strategy for high temperature geothermal resources in the Philippines - an update

    International Nuclear Information System (INIS)

    Bayrante, L.F.; Ferrer, H.P.; Barnett, P.R.

    1992-01-01

    After nearly two decades of geoscientific-exploration at 45 geothermal areas in the Philippines, the Philippine National Oil Company-Energy Development Corporation (PNOC-EDC) has developed a multi-disciplinary approach for exploring country's geothermal resources. It suitability for crater-hosted magmatic geothermal systems is currently being evaluated in the light of new data from six recently drilled prospects. New techniques are under consideration for future exploration programmes. (auth.). 59 refs.; 5 figs

  1. Spatial Characteristics of Geothermal Spring Temperatures and Discharge Rates in the Tatun Volcanic Area, Taiwan

    Science.gov (United States)

    Jang, C. S.; Liu, C. W.

    2014-12-01

    The Tatun volcanic area is the only potential volcanic geothermal region in the Taiwan island, and abundant in hot spring resources owing to stream water mixing with fumarolic gases. According to the Meinzer's classification, spring temperatures and discharge rates are the most important properties for characterizing spring classifications. This study attempted to spatially characterize spring temperatures and discharge rates in the Tatun volcanic area, Taiwanusing indicator kriging (IK). First, data on spring temperatures and discharge rates, which were collected from surveyed data of the Taipei City Government, were divided into high, moderate and low categories according to spring classification criteria, and the various categories were regarded as estimation thresholds. Then, IK was adopted to model occurrence probabilities of specified temperatures and discharge rates in springs, and to determine their classifications based on estimated probabilities. Finally, nine combinations were obtained from the classifications of temperatures and discharge rates in springs. Moreover, the combinations and features of spring water were spatially quantified according to seven sub-zones of spring utilization. A suitable and sustainable development strategy of the spring area was proposed in each sub-zone based on probability-based combinations and features of spring water.The research results reveal that the probability-based classifications using IK provide an excellent insight in exploring the uncertainty of spatial features in springs, and can provide Taiwanese government administrators with detailed information on sustainable spring utilization and conservation in the overexploited spring tourism areas. The sub-zones BT (Beitou), RXY (Rd. Xingyi), ZSL (Zhongshanlou) and LSK (Lengshuikeng) with high or moderate discharge rates are suitable to supply spring water for tourism hotels.Local natural hot springs should be planned in the sub-zones DBT (Dingbeitou), ZSL, XYK

  2. Stream hydraulics and temperature determine the metabolism of geothermal Icelandic streams

    Directory of Open Access Journals (Sweden)

    Demars B. O.L.

    2011-07-01

    Full Text Available Stream ecosystem metabolism plays a critical role in planetary biogeochemical cycling. Stream benthic habitat complexity and the available surface area for microbes relative to the free-flowing water volume are thought to be important determinants of ecosystem metabolism. Unfortunately, the engineered deepening and straightening of streams for drainage purposes could compromise stream natural services. Stream channel complexity may be quantitatively expressed with hydraulic parameters such as water transient storage, storage residence time, and water spiralling length. The temperature dependence of whole stream ecosystem respiration (ER, gross primary productivity (GPP and net ecosystem production (NEP = GPP − ER has recently been evaluated with a “natural experiment” in Icelandic geothermal streams along a 5–25 °C temperature gradient. There remained, however, a substantial amount of unexplained variability in the statistical models, which may be explained by hydraulic parameters found to be unrelated to temperature. We also specifically tested the additional and predicted synergistic effects of water transient storage and temperature on ER, using novel, more accurate, methods. Both ER and GPP were highly related to water transient storage (or water spiralling length but not to the storage residence time. While there was an additional effect of water transient storage and temperature on ER (r2 = 0.57; P = 0.015, GPP was more related to water transient storage than temperature. The predicted synergistic effect could not be confirmed, most likely due to data limitation. Our interpretation, based on causal statistical modelling, is that the metabolic balance of streams (NEP was primarily determined by the temperature dependence of respiration. Further field and experimental work is required to test the predicted synergistic effect on ER. Meanwhile, since higher metabolic activities allow for higher pollutant degradation or uptake

  3. Geothermal energy

    Directory of Open Access Journals (Sweden)

    Manzella A.

    2015-01-01

    Full Text Available Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse-gas (GHG emissions. Geothermal energy is stored in rocks and in fluids circulating in the underground. Electricity generation usually requires geothermal resources temperatures of over 100°C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology, spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Geothermal technology, which has focused so far on extracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where underground fluids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermal energy in the Earth’s crust.

  4. Community Structure and Function of High-temperature Chlorophototrophic Microbial Mats Inhabiting Diverse Geothermal Environments

    Directory of Open Access Journals (Sweden)

    William P. Inskeep

    2013-06-01

    Full Text Available Six phototrophic microbial mat communities from different geothermal springs (YNP were studied using metagenome sequencing and geochemical analyses. The primary goals of this work were to determine differences in community composition of high-temperature phototrophic mats distributed across the Yellowstone geothermal ecosystem, and to identify metabolic attributes of predominant organisms present in these communities that may correlate with environmental attributes important in niche differentiation. Random shotgun metagenome sequences from six phototrophic communities (average~ 53 Mbp/site were subjected to multiple taxonomic, phylogenetic and functional analyses. All methods, including G+C content distribution, MEGAN analyses and oligonucleotide frequency-based clustering, provided strong support for the dominant community members present in each site. Cyanobacteria were only observed in non-sulfidic sites; de novo assemblies were obtained for Synechococcus-like populations at Chocolate Pots (CP_7 and Fischerella-like populations at White Creek (WC_6. Chloroflexi-like sequences (esp. Roseiflexus and/or Chloroflexus spp. were observed in all six samples and contained genes involved in bacteriochlorophyll biosynthesis and the 3-hydroxypropionate carbon fixation pathway. Other major sequence assemblies were obtained for a Chlorobiales population from CP_7 (proposed family Thermochlorobacteriaceae, and an anoxygenic, sulfur-oxidizing Thermochromatium-like (Gamma-proteobacteria population from Bath Lake Vista Annex (BLVA_20. Additional sequence coverage is necessary to establish more complete assemblies of other novel bacteria in these sites (e.g., Bacteroidetes and Firmicutes; however, current assemblies suggested that several of these organisms play important roles in heterotrophic and fermentative metabolisms. Definitive linkages were established between several of the dominant phylotypes present in these habitats and important functional

  5. Parametric Analysis of the feasibility of low-temperature geothermal heat recovery in sedimentary basins

    Science.gov (United States)

    Tomac, I.; Caulk, R.

    2016-12-01

    The current study explored the feasibility of heat recovery through the installation of heat exchangers in abandoned oil and gas wells. Finite Element Methods (FEM) were employed to determine the effects of various site specific parameters on production fluid temperature. Specifically, the study parameterized depth of well, subsurface temperature gradient, sedimentary rock conductivity, and flow rate. Results show that greater well depth is associated with greater heat flow, with the greatest returns occurring between depths of 1.5 km and 7 km. Beyond 7 km, the rate of return decreases due to a non-linear increase of heat flow combined with a continued linear increase of pumping cost. One cause for the drop of heat flow was the loss of heat as the fluid travels from depth to the surface. Further analyses demonstrated the benefit of an alternative heat exchanger configuration characterized by thermally insulated sections of the upward heat exchanger. These simulations predict production fluid temperature gains between 5 - 10 oC, which may be suitable for geothermal heat pump applications.

  6. CLINICAL STUDY TO EVALUATE THE VISUAL OUTCOME AND PATIENT COMFORT IN LASIK AND PHOTOREFRACTIVE KERATECTOMY IN LOW-TO-MODERATE MYOPIC ASTIGMATISM PATIENTS

    OpenAIRE

    Ashok Kumar P; Ananda Babu M; Radha Priyadharshini R; Jeevitha A

    2017-01-01

    BACKGROUND To evaluate visual outcomes following LASIK and Photorefractive Keratectomy (PRK) in low-to-moderate myopia and/or myopic astigmatism in age and refractive error matched eyes. MATERIALS AND METHODS Of a total 30 patients aged ≥21 years, 20 (40 eyes) underwent LASIK and 10 (20 eyes) underwent PRK for low-to-moderate myopia or myopic astigmatism. LASIK was performed with the Alcon wave light 500 and PRK with the alcohol application for epithelial removal. All abl...

  7. Geothermal Thermoelectric Generation (G-TEG) with Integrated Temperature Driven Membrane Distillation and Novel Manganese Oxide for Lithium Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Renew, Jay [Southern Research Inst., Birmingham, AL (United States); Hansen, Tim [Southern Research Inst., Birmingham, AL (United States)

    2017-06-01

    Southern Research Institute (Southern) teamed with partners Novus Energy Technologies (Novus), Carus Corporation (Carus), and Applied Membrane Technology, Inc. (AMT) to develop an innovative Geothermal ThermoElectric Generation (G-TEG) system specially designed to both generate electricity and extract high-value lithium (Li) from low-temperature geothermal brines. The process combined five modular technologies including – silica removal, nanofiltration (NF), membrane distillation (MD), Mn-oxide sorbent for Li recovery, and TEG. This project provides a proof of concept for each of these technologies. The first step in the process is silica precipitation through metal addition and pH adjustment to prevent downstream scaling in membrane processes. Next, the geothermal brine is concentrated with the first of a two stage MD system. The first stage MD system is made of a high-temperature material to withstand geothermal brine temperatures up to 150C.° The first stage MD is integrated with a G-TEG module for simultaneous energy generation. The release of energy from the MD permeate drives heat transfer across the TE module, producing electricity. The first stage MD concentrate is then treated utilizing an NF system to remove Ca2+ and Mg2+. The NF concentrate will be disposed in the well by reinjection. The NF permeate undergoes concentration in a second stage of MD (polymeric material) to further concentrate Li in the NF permeate and enhance the efficiency of the downstream Li recovery process utilizing a Mn-oxide sorbent. Permeate from both the stages of the MD can be beneficially utilized as the permeates will contain less contaminants than the feed water. The concentrated geothermal brines are then contacted with the Mn-oxide sorbent. After Li from the geothermal brine is adsorbed on the sorbent, HCl is then utilized to regenerate the sorbent and recover the Li. The research and development project showed that the Si removal goal (>80%) could

  8. Japanese geothermics

    International Nuclear Information System (INIS)

    Laplaige, P.

    1995-01-01

    At the end of the seventies, the NEDO (New Energy and Industrial Technology Development Organisation) and the Central Research Institute of Electric Power Industry have started two independent projects of deep geothermics research in Honshu island (Japan). The two sites are 50 km apart of each other and the boreholes have been drilled up to 2300 and 1100 m of depth, respectively, in hot-dry moderately fractured volcanic rocks. These sites are characterized by high geothermal gradients with a rock temperature reaching 250 C at the bottom of the wells. Hydraulic circulation tests are still in progress to evaluate the profitability of these sites. (J.S.). 1 fig., 1 photo

  9. Resource investigation of low- and moderate-temperature geothermal areas in Paso Robles, California

    Energy Technology Data Exchange (ETDEWEB)

    Campion, L.F.; Chapman, R.H.; Chase, G.W.; Youngs, L.G.

    1983-01-01

    Ninety-eight geothermal wells and springs were identified and plotted, and a geologic map and cross sections were compiled. Detailed geophysical, geochemical, and geological surveys were conducted. The geological and geophysical work delineated the basement highs and trough-like depressions that can exercise control on the occurrence of the thermal waters. The Rinconada fault was also evident. Cross sections drawn from oil well logs show the sediments conforming against these basement highs and filling the depressions. It is along the locations where the sediments meet the basement highs that three natural warm springs in the area occur. Deep circulation of meteoric waters along faults seems to be a reasonable source for the warm water. The Santa Margarita, Pancho Rico, and Paso Robles Formations would be the first permeable zones that abut the faults through which water would enter. Temperatures and interpretation of well logs indicate the warmest aquifer at the base of the Paso Robles Formation. Warm water may be entering higher up in the section, but mixing with water from cooler zones seems to be evident. Geothermometry indicates reservoir temperatures could be as high as 91/sup 0/C (196/sup 0/F).

  10. Evaluation of the environmental sustainability of a micro CHP system fueled by low-temperature geothermal and solar energy

    International Nuclear Information System (INIS)

    Ruzzenenti, Franco; Bravi, Mirko; Tempesti, Duccio; Salvatici, Enrica; Manfrida, Giampaolo; Basosi, Riccardo

    2014-01-01

    Highlights: • Binary, ORC technology avoids CO 2 , but raises questions about environmental impact. • We proposed a micro-size system that combines geothermal energy with solar energy. • The small scale and the solar energy input edges the energy profitability. • The system’s performance is appreciable if applied to existing wells. • The feasibility of exploiting abandoned wells is preliminarily evaluated. - Abstract: In this paper we evaluate the environmental sustainability of a small combined heat and power (CHP) plant operating through an Organic Rankine Cycle (ORC). The heat sources of the system are from geothermal energy at low temperature (90–95 °C) and solar energy. The designed system uses a solar field composed only of evacuated, non-concentrating solar collectors, and work is produced by a single turbine of 50 kW. The project addresses an area of Tuscany, but it could be reproduced in areas where geothermal energy is extensively developed. Therefore, the aim is to exploit existing wells that are either unfit for high-enthalpy technology, abandoned or never fully developed. Furthermore, this project aims to aid in downsizing the geothermal technology in order to reduce the environmental impact and better tailor the production system to the local demand of combined electric and thermal energy. The environmental impact assessment was performed through a Life Cycle Analysis and an Exergy Life Cycle Analysis. According to our findings the reservoir is suitable for a long-term exploitation of the designed system, however, the sustainability and the energy return of this latter is edged by the surface of the heat exchanger and the limited running hours due to the solar plant. Therefore, in order to be comparable to other renewable resources or geothermal systems, the system needs to develop existing wells, previously abandoned

  11. Temperature measurement of geothermal wells by optical fiber sensor; Hikari fiber sensor wo mochiita chinetsusei no ondo bunpu keisoku

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, N; Sakaguchi, K [Geological Survey of Japan, Tsukuba (Japan)

    1996-10-01

    Experiments of temperature measurement were conducted in high temperature and high pressure geothermal wells using optical fiber sensor. A temperature measurement system using optical fiber sensor was applied to geothermal wells. Working availability was confirmed under the condition up to the depth of 1,750 m and the temperature of 240 centigrade. Observed values agreed well with those observed by the conventional temperature logging. Durability of the optical fiber sensor was also sufficient. The maximum standard deviations of measured values were 1.3 centigrade at the depth of 1,750 m at 195 centigrade for the loop-type sensor, and 3.7 centigrade at the depth of 365 m at about 200 centigrade for the single-end sensor. Although the accuracy was inferior to the conventional measurement using a thermo couple, it was enough to be applied to usual temperature logging. Furthermore, for this system, the temperature profile in the whole well can be monitored, simultaneously. Through the experiments, the detailed successive change of temperature profile accompanied with the water injection can be clearly illustrated. 3 refs., 7 figs.

  12. Sustainable renewable energy seawater desalination using combined-cycle solar and geothermal heat sources

    KAUST Repository

    Missimer, Thomas M.

    2013-01-01

    Key goals in the improvement of desalination technology are to reduce overall energy consumption, make the process "greener," and reduce the cost of the delivered water. Adsorption desalination (AD) is a promising new technology that has great potential to reduce the need for conventional power, to use solely renewable energy sources, and to reduce the overall cost of water treatment. This technology can desalt seawater or water of even higher salinity using waste heat, solar heat, or geothermal heat. An AD system can operate effectively at temperatures ranging from 55 to 80 °C with perhaps an optimal temperature of 80 °C. The generally low temperature requirement for the feedwater allows the system to operate quite efficiently using an alternative energy source, such as solar power. Solar power, particularly in warm dry regions, can generate a consistent water temperature of about 90 °C. Although this temperature is more than adequate to run the system, solar energy collection only can occur during daylight hours, thereby necessitating the use of heat storage during nighttime or very cloudy days. With increasing capacity, the need for extensive thermal storage may be problematic and could add substantial cost to the development of an AD system. However, in many parts of the world, there are subsurface geothermal energy sources that have not been extensively used. Combining a low to moderate geothermal energy recovery system to an AD system would provide a solution to the thermal storage issue. However, geothermal energy development from particularly Hot Dry Rock is limited by the magnitude of the heat flow required for the process and the thermal conductivity of the rock material forming the heat reservoir. Combining solar and geothermal energy using an alternating 12-h cycle would reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of renewable energy. © 2013 Desalination Publications.

  13. Distribution of high-temperature (>150 °C) geothermal resources in California

    Science.gov (United States)

    Sass, John H.; Priest, Susan S.

    2002-01-01

    California contains, by far, the greatest geothermal generating capacity in the United States, and with the possible exception of Alaska, the greatest potential for the development of additional resources. California has nearly 2/3 of the US geothermal electrical installed capacity of over 3,000 MW. Depending on assumptions regarding reservoir characteristics and future market conditions, additional resources of between 2,000 and 10,000 MWe might be developed (see e.g., Muffler, 1979).

  14. Geothermal energy for greenhouses

    Science.gov (United States)

    Jacky Friedman

    2009-01-01

    Geothermal energy is heat (thermal) derived from the earth (geo). The heat flows along a geothermal gradient from the center of the earth to the surface. Most of the heat arrives at the surface of the earth at temperatures too low for much use. However, plate tectonics ensure that some of the heat is concentrated at temperatures and depths favorable for its commercial...

  15. Geothermal Power Technologies

    DEFF Research Database (Denmark)

    Montagud, Maria E. Mondejar; Chamorro, C.R.

    2017-01-01

    Although geothermal energy has been widely deployed for direct use in locations with especial geologic manifestations, its potential for power generation has been traditionally underestimated. Recent technology developments in drilling techniques and power conversion technologies from low......-temperature heat resources are bringing geothermal energy to the spotlight as a renewable baseload energy option for a sustainable energy mix. Although the environmental impact and economic viability of geothermal exploitation must be carefully evaluated for each case, the use of deep low-temperature geothermal...... reservoirs could soon become an important contributor to the energy generation around the world....

  16. Performance analysis of electricity generation by the medium temperature geothermal resources: Velika Ciglena case study

    International Nuclear Information System (INIS)

    Rašković, Predrag; Guzović, Zvonimir; Cvetković, Svetislav

    2013-01-01

    During the last decade, a design of an energy efficient and cost effective geothermal plant represents a significant and on-going technical challenge in all the Western Balkan countries. In the Republic of Croatia, the geothermal field Velika Ciglena is identified as one of the most valuable geothermal heat sources and probably the location where the first geothermal plant in the Western Balkan area will be built. The purpose of this work is the conceptual design and performance analysis of the binary plants–the one which operates under the Organic Rankine Cycle (ORC) and the other under Kalina (KLN) cycle–which can be used for geothermal energy utilization in Velika Ciglena. A conceptual plant design is performed by the equation-oriented modelling approach and supported by the two steady-state spreadsheet simulators. The performance analysis of all design solutions is conducted through energy and exergy analysis, and by the estimated total cost of operating units in the plant. The results of the analysis indicate that the plant design based on the ORC cycle has a higher thermodynamic efficiency and lower cost of equipment, and consequently, it is more suitable for the future geothermal plant in Velika Ciglena. - Highlights: ► Paper presents the analysis of binary geothermal plant for the utilization of recourses in Velika Ciglena field (Croatia). ► Thermodynamic and economical parameters of both cycles are calculated by the spreadsheet simulation software. ► The results of performance analysis indicate the advantage of electricity production based on ORC cycle

  17. Seismic Velocity/Temperature Correlations and a Possible New Geothermometer: Insights from Exploration of a High-Temperature Geothermal System on Montserrat, West Indies

    Directory of Open Access Journals (Sweden)

    Graham Alexander Ryan

    2014-10-01

    Full Text Available In 2013, two production wells were drilled into a geothermal reservoir on Montserrat, W.I. (West Indies Drilling results confirmed the main features of a previously developed conceptual model. The results confirm that below ~220 °C there is a negative correlation between reservoir temperature and seismic velocity anomaly. However, above ~220 °C there is a positive correlation. We hypothesise that anomalous variations in seismic velocity within the reservoir are controlled to first order by the hydrothermal mineral assemblage. This study suggests a new geophysical thermometer which can be used to estimate temperatures in three dimensions with unprecedented resolution and to indicate the subsurface fluid pathways which are the target of geothermal exploitation.

  18. Bacterial corrosion in low-temperature geothermal. Mechanisms of corrosion by sulphate-reducing bacteria

    International Nuclear Information System (INIS)

    Daumas, Sylvie

    1987-01-01

    Within the frame of researches aimed at determining the causes of damages noticed on geothermal equipment, this research thesis aims at assessing the respective importance of physical-chemical processes and bacterial intervention in corrosion phenomena. It proposes an ecological approach of the fluid sampled in the Creil geothermal power station. The aim is to define the adaptation and activity degree of isolated sulphate-reducing bacteria with respect to their environment conditions. The author studied the effect of the development of these bacteria on the corrosion of carbon steel used in geothermal. Thus, he proposes a contribution to the understanding of mechanisms related to iron attack by these bacteria. Electrochemical techniques have been adapted to biological processes and used to measure corrosion [fr

  19. Long-term effectiveness and cost-effectiveness of high versus low-to-moderate intensity resistance and endurance exercise interventions among cancer survivors

    NARCIS (Netherlands)

    Kampshoff, C. S.; van Dongen, J. M.; van Mechelen, W.; Schep, G.; Vreugdenhil, A.; Twisk, J. W.R.; Bosmans, J. E.; Brug, J.; Chinapaw, M. J.M.; Buffart, Laurien M.

    Purpose: This study aimed to evaluate the long-term effectiveness and cost-effectiveness of high intensity (HI) versus low-to-moderate intensity (LMI) exercise on physical fitness, fatigue, and health-related quality of life (HRQoL) in cancer survivors. Methods: Two hundred seventy-seven cancer

  20. Low to moderate alcohol consumption on serum vitamin D and other indicators of bone health in postmenopausal women in a controlled feeding study

    Science.gov (United States)

    Heavy alcohol drinking adversely affects vitamin D status and bone health. However, data from randomized, placebo-controlled trials (RCTs) on the effects of low to moderate alcohol consumption on vitamin D status and bone health in humans is unavailable. The objective of this cross-over RCT was to e...

  1. Coordination of geothermal research

    Energy Technology Data Exchange (ETDEWEB)

    Jessop, A.M.; Drury, M.J.

    1983-01-01

    Visits were made in 1983 to various investigators and institutions in Canada to examine developments in geothermal research. Proposals for drilling geothermal wells to provide hot water for heating at a college in Prince Edward Island were made. In Alberta, the first phase of a program examining the feasibility of mapping sedimentary geothermal reservoirs was discussed. Some sites for possible geothermal demonstration projects were identified. In British Columbia, discussions were held between BC Hydro and Energy, Mines and Resources Canada on the drilling of a research hole into the peak of a temperature anomaly in the Meager Creek Valley. The British Columbia government has offered blocks of land in the Mount Cayley volcanic complex for lease to develop geothermal resources. A list of papers of interest to the Canadian geothermal energy program is appended.

  2. Geothermal energy

    International Nuclear Information System (INIS)

    Rummel, F.; Kappelmeyer, O.; Herde, O.A.

    1992-01-01

    Objective of this brochure is to present the subject Geothermics and the possible use of geothermal energy to the public. The following aspects will be refered to: -present energy situation -geothermal potential -use of geothermal energy -environemental aspects -economics. In addition, it presents an up-dated overview of geothermal projects funded by the German government, and a list of institutions and companies active in geothermal research and developments. (orig./HP) [de

  3. Low Temperature Geothermal Play Fairway Analysis For The Appalachian Basin: Phase 1 Revised Report November 18, 2016

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Teresa E. [Cornell Univ., Ithaca, NY (United States); Richards, Maria C. [Southern Methodist Univ., Dallas, TX (United States); Horowitz, Franklin G. [Cornell Univ., Ithaca, NY (United States); Camp, Erin [Cornell Univ., Ithaca, NY (United States); Smith, Jared D. [Cornell Univ., Ithaca, NY (United States); Whealton, Calvin A. [Cornell Univ., Ithaca, NY (United States); Stedinger, Jery R. [Cornell Univ., Ithaca, NY (United States); Hornbach, Matthew J. [Southern Methodist Univ., Dallas, TX (United States); Frone, Zachary S. [Southern Methodist Univ., Dallas, TX (United States); Tester, Jefferson W. [Cornell Univ., Ithaca, NY (United States); Anderson, Brian [West Virginia Univ., Morgantown, WV (United States); Welcker, Kelydra [West Virginia Univ., Morgantown, WV (United States); Chickering Pace, Catherine [Southern Methodist Univ., Dallas, TX (United States); He, Xiaoning [West Virginia Univ., Morgantown, WV (United States); Magnani, Maria Beatrice [Southern Methodist Univ., Dallas, TX (United States); Bolat, Rahmi [Southern Methodist Univ., Dallas, TX (United States)

    2016-11-18

    Geothermal energy is an attractive sustainable energy source. Yet project developers need confirmation of the resource base to warrant their time and financial resources. The Geothermal Play Fairway Analysis of the Appalachian Basin evaluated risk metrics that communicate the favorability of potential low-temperature geothermal energy resources in reservoirs more than 1000 m below the surface. This analysis is focused on the direct use of the heat, rather than on electricity production. Four risk factors of concern for direct-use geothermal plays in the Appalachian Basin portions of New York, Pennsylvania, and West Virginia are examined individually, and then in combination: 1) thermal resource quality, 2) natural reservoir quality, 3) induced seismicity, and 4) utilization opportunities. Uncertainty in the risk estimation is quantified. Based on these metrics, geothermal plays in the Appalachian Basin were identified as potentially viable for a variety of direct-use-heat applications. The methodologies developed in this project may be applied in other sedimentary basins as a foundation for low temperature (50-150 °C), direct use geothermal resource, risk, and uncertainty assessment. Three methods with which to combine the four risk factors were used. Among these, the averaging of the individual risk factors indicates the most favorable counties within the study area are the West Virginia counties of Monongalia, Harrison, Lewis (dubbed the Morgantown–Clarksburg play fairway), Putnam, and Kanawha (Charleston play fairway), the New York counties of Chemung and Steuben plus adjacent Bradford county in Pennsylvania (Corning–Ithaca play fairway), and the Pennsylvania counties of Mercer, Crawford, Erie, and Warren, and adjacent Chautauqua county in New York (together, the Meadville–Jamestown play fairway). These higher priority regions are surrounded by broader medium priority zones. Also worthy of additional exploration is a broad region near Pittsburgh

  4. The Significance of Acid Alteration in the Los Humeros High-Temperature Geothermal Field, Puebla, Mexico.

    Science.gov (United States)

    Elders, W. A.; Izquierdo, G.

    2014-12-01

    The Los Humeros geothermal field is a high-enthalpy hydrothermal system with more than 40 drilled deep wells, mostly producing high steam fractions at > 300oC. However, although it has a large resource potential, low permeability and corrosive acid fluids have hampered development so that it currently has an installed electrical generating capacity of only 40 MWe. The widespread production of low pH fluids from the reservoir is inconsistent with the marked absence in the reservoir rocks of hydrothermal minerals typical of acid alteration. Instead the hydrothermal alteration observed is typical of that due to neutral to alkaline pH waters reacting with the volcanic rocks of the production zones. Thus it appears that since the reservoir has recently suffered a marked drop in fluid pressure and is in process of transitioning from being water-dominated to being vapor-dominated. However sparse examples of acid leaching are observed locally at depths of about 2 km in the form of bleached, intensely silicified zones, in low permeability and very hot (>350oC) parts of reservoir. Although these leached rocks retain their primary volcanic and pyroclastic textures, they are altered almost entirely to microcrystalline quartz, with some relict pseudomorphs of plagioclase phenocrysts and traces of earlier-formed hydrothermal chlorite and pyrite. These acid-altered zones are usually only some tens of meters thick and deeper rocks lack such silicification. The acid fluids responsible for their formation could either be magmatic volatiles, or could be formed during production (e.g. reaction of water and salts forming hydrogen chloride by hydrolysis at high temperatures). The very high boron content of the fluids produced by the Los Humeros wells suggests that their ultimate source is most likely magmatic gases. However, these acid gases did not react widely with the rocks. We suggest that the silicified zones are forming locally where colder descending waters are encountering

  5. Ground Thermal Diffusivity Calculation by Direct Soil Temperature Measurement. Application to very Low Enthalpy Geothermal Energy Systems.

    Science.gov (United States)

    Andújar Márquez, José Manuel; Martínez Bohórquez, Miguel Ángel; Gómez Melgar, Sergio

    2016-02-29

    This paper presents a methodology and instrumentation system for the indirect measurement of the thermal diffusivity of a soil at a given depth from measuring its temperature at that depth. The development has been carried out considering its application to the design and sizing of very low enthalpy geothermal energy (VLEGE) systems, but it can has many other applications, for example in construction, agriculture or biology. The methodology is simple and inexpensive because it can take advantage of the prescriptive geotechnical drilling prior to the construction of a house or building, to take at the same time temperature measurements that will allow get the actual temperature and ground thermal diffusivity to the depth of interest. The methodology and developed system have been tested and used in the design of a VLEGE facility for a chalet with basement at the outskirts of Huelva (a city in the southwest of Spain). Experimental results validate the proposed approach.

  6. The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on selective and sustained attention in 5-year-old children

    DEFF Research Database (Denmark)

    Underbjerg, Mette; Kesmodel, Ulrik S.; Landrø, Nils Inge

    2012-01-01

    Please cite this paper as: Underbjerg M, Kesmodel U, Landrø N, Bakketeig L, Grove J, Wimberley T, Kilburn T, Svaerke C, Thorsen P, Mortensen E. The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on selective and sustained attention in 5-year-old children. BJOG...... 2012;119:1211-1221. Objective  The aim was to examine the effects of low to moderate maternal alcohol consumption and binge drinking in early pregnancy on children's attention at 5 years of age. Design  Prospective follow-up study. Setting  Neuropsychological testing in four Danish cities 2003......-2008. Population  A cohort of 1628 women and their children sampled from the Danish National Birth Cohort. Methods  Participants were sampled based on maternal alcohol consumption during pregnancy. At 5 years of age, the children were tested with the recently developed Test of Everyday Attention for Children...

  7. The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on executive function in 5-year-old children

    DEFF Research Database (Denmark)

    Skogerbø, A; Kesmodel, Ulrik S.; Wimberley, Theresa

    2012-01-01

    Please cite this paper as: SkogerbøÅ, Kesmodel U, Wimberley T, Støvring H, Bertrand J, Landrø N, Mortensen E. The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on executive function in 5-year-old children. BJOG 2012;119:1201-1210. Objective  To examine...... the effects of low to moderate maternal alcohol consumption and binge drinking in early pregnancy on children's executive functions at the age of 5 years. Design  Follow-up study. Setting  Neuropsychological testing in four Danish cities 2003-2008. Population  A cohort of 1628 women and their children sampled...... from the Danish National Birth Cohort. Methods  Participants were sampled based on maternal alcohol drinking patterns during early pregnancy. When the children were 5 years old, the parent and teacher forms of the Behaviour Rating Inventory of Executive Function (BRIEF) were completed by the mothers...

  8. Efficacy and safety of transcatheter aortic valve replacement in aortic stenosis patients at low to moderate surgical risk: a comprehensive meta-analysis

    OpenAIRE

    Elmaraezy, Ahmed; Ismail, Ammar; Abushouk, Abdelrahman Ibrahim; Eltoomy, Moutaz; Saad, Soha; Negida, Ahmed; Abdelaty, Osama Mahmoud; Abdallah, Ahmed Ramadan; Aboelfotoh, Ahmed Magdy; Hassan, Hossam Mahmoud; Elmaraezy, Aya Gamal; Morsi, Mahmoud; Althaher, Farah; Althaher, Moath; AlSafadi, Ammar M.

    2017-01-01

    Background Recently, transcatheter aortic valve replacement (TAVR) has become the procedure of choice in high surgical risk patients with aortic stenosis (AS). However, its value is still debated in operable AS cases. We performed this meta-analysis to compare the safety and efficacy of TAVR to surgical aortic valve replacement (SAVR) in low-to-moderate surgical risk patients with AS. Methods A systematic search of five authentic databases retrieved 11 eligible studies (20,056 patients). Rele...

  9. Geothermal Energy

    International Nuclear Information System (INIS)

    Haluska, Oscar P.; Tangir, Daniel; Perri, Matias S.

    2002-01-01

    A general overview of geothermal energy is given that includes a short description of the active and stable areas in the world. The possibilities of geothermal development in Argentina are analyzed taking into account the geothermal fields of the country. The environmental benefits of geothermal energy are outlined

  10. Geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Gasparovic, N

    1962-07-01

    Live steam, transformed steam, and steam produced by expansion flashing are outlined with respect to their use in the production of electricity. The capacity, pressure, and temperature of a steam must be determined empirically by exploratory drilling. These factors are dependent on time and on the extent of nearby drilling-activity. Particulars of geothermal-steam power-plants such as steam dryness, hot-water flashing, condensation, gas extraction, and corrosion are discussed in detail. All available data (as per 1962) concerning the costs of operation and construction of geothermal power plants are tabulated. For space-heating purposes, two basic systems are utilized. When little corrosion or precipitation is expected, an open system is used, otherwise, closed systems are necessary. The space-heating system of Reykjavik, Iceland is cited as an example. A brief description of industrial applications of geothermal energy, such as the extraction of NaCl, D/sub 2/O, or boric acid, is provided. Thirty-two references are given.

  11. Temperature and heat flux changes at the base of Laurentide ice sheet inferred from geothermal data (evidence from province of Alberta, Canada)

    Science.gov (United States)

    Demezhko, Dmitry; Gornostaeva, Anastasia; Majorowicz, Jacek; Šafanda, Jan

    2018-01-01

    Using a previously published temperature log of the 2363-m-deep borehole Hunt well (Alberta, Canada) and the results of its previous interpretation, the new reconstructions of ground surface temperature and surface heat flux histories for the last 30 ka have been obtained. Two ways to adjust the timescale of geothermal reconstructions are discussed, namely the traditional method based on the a priori data on thermal diffusivity value, and the alternative one including the orbital tuning of the surface heat flux and the Earth's insolation changes. It is shown that the second approach provides better agreement between geothermal reconstructions and proxy evidences of deglaciation chronology in the studied region.

  12. Advanced Geothermal Turbodrill

    Energy Technology Data Exchange (ETDEWEB)

    W. C. Maurer

    2000-05-01

    Approximately 50% of the cost of a new geothermal power plant is in the wells that must be drilled. Compared to the majority of oil and gas wells, geothermal wells are more difficult and costly to drill for several reasons. First, most U.S. geothermal resources consist of hot, hard crystalline rock formations which drill much slower than the relatively soft sedimentary formations associated with most oil and gas production. Second, high downhole temperatures can greatly shorten equipment life or preclude the use of some technologies altogether. Third, producing viable levels of electricity from geothermal fields requires the use of large diameter bores and a high degree of fluid communication, both of which increase drilling and completion costs. Optimizing fluid communication often requires creation of a directional well to intersect the best and largest number of fracture capable of producing hot geothermal fluids. Moineau motor stators made with elastomers cannot operate at geothermal temperatures, so they are limited to the upper portion of the hole. To overcome these limitations, Maurer Engineering Inc. (MEI) has developed a turbodrill that does not use elastomers and therefore can operate at geothermal temperatures. This new turbodrill uses a special gear assembly to reduce the output speed, thus allowing a larger range of bit types, especially tri-cone roller bits, which are the bits of choice for drilling hard crystalline formations. The Advanced Geothermal Turbodrill (AGT) represents a significant improvement for drilling geothermal wells and has the potential to significantly reduce drilling costs while increasing production, thereby making geothermal energy less expensive and better able to compete with fossil fuels. The final field test of the AGT will prepare the tool for successful commercialization.

  13. Development of geothermal field following the 2000 eruption of Usu volcano as revealed by ground temperature, resistivity and self-potential variations

    Directory of Open Access Journals (Sweden)

    T. Mogi

    2007-06-01

    Full Text Available The 2000 eruption of Usu volcano, NE Japan, took place on the foot of the somma, and formed a cryptodome of 65 m high accompanying numerous faults. We made repeated measurements of ground temperature, Self-Potential (SP and electrical resistivity, in order to clarify the mechanism of development of the newly formed geothermal field on the fault zone. Prior to the expansion of the geothermal field, we detected a resistive zone at the center of the geothermal zone and it supposed to evidence that the zone involving dry steam phase had been formed beneath the fault zone. A rapid expansion of the geothermal field followed along the fault zone away from the craters. The place of maximum amplitude of the SP field also migrated following the expansion of the high ground temperature zone. The high resistive part has shrunk as a consequence of the progress of condensation to warm the surroundings. Based on the observations, we delineated the process of the hydrothermal circulation. Considering the topographic effect of the SP field observed on the highly permeable zone in the Usu somma, the potential flow along the slope of the soma was expected to play an important role to promote the rapid expansion of the geothermal field and the migration of the most active part.

  14. Potential of geothermal systems in Picardy

    OpenAIRE

    Dourlat, Estelle

    2017-01-01

    Geothermal systems are not only about electrical plants or urban heating networks, but also concerned with geothermal energy assisted with a heat pump. In the former region of Picardy (North of France), 97% of the territory is suitable for very low temperature geothermal power. The French Agency for the Environment and Energy Management and the Picardy Region decided in 2016 to finance a facilitator to encourage geothermal use. To carry out this aim, it is important to consider the geothermal...

  15. Assessment of the Appalachian Basin Geothermal Field: Combining Risk Factors to Inform Development of Low Temperature Projects

    Science.gov (United States)

    Smith, J. D.; Whealton, C.; Camp, E. R.; Horowitz, F.; Frone, Z. S.; Jordan, T. E.; Stedinger, J. R.

    2015-12-01

    Exploration methods for deep geothermal energy projects must primarily consider whether or not a location has favorable thermal resources. Even where the thermal field is favorable, other factors may impede project development and success. A combined analysis of these factors and their uncertainty is a strategy for moving geothermal energy proposals forward from the exploration phase at the scale of a basin to the scale of a project, and further to design of geothermal systems. For a Department of Energy Geothermal Play Fairway Analysis we assessed quality metrics, which we call risk factors, in the Appalachian Basin of New York, Pennsylvania, and West Virginia. These included 1) thermal field variability, 2) productivity of natural reservoirs from which to extract heat, 3) potential for induced seismicity, and 4) presence of thermal utilization centers. The thermal field was determined using a 1D heat flow model for 13,400 bottomhole temperatures (BHT) from oil and gas wells. Steps included the development of i) a set of corrections to BHT data and ii) depth models of conductivity stratigraphy at each borehole based on generalized stratigraphy that was verified for a select set of wells. Wells are control points in a spatial statistical analysis that resulted in maps of the predicted mean thermal field properties and of the standard error of the predicted mean. Seismic risk was analyzed by comparing earthquakes and stress orientations in the basin to gravity and magnetic potential field edges at depth. Major edges in the potential fields served as interpolation boundaries for the thermal maps (Figure 1). Natural reservoirs were identified from published studies, and productivity was determined based on the expected permeability and dimensions of each reservoir. Visualizing the natural reservoirs and population centers on a map of the thermal field communicates options for viable pilot sites and project designs (Figure 1). Furthermore, combining the four risk

  16. Low-Temperature Enhanced Geothermal System using Carbon Dioxide as the Heat-Transfer Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Eastman, Alan D. [GreenFire Energy, Emeryville, CA (United States)

    2014-07-24

    This report describes work toward a supercritical CO2-based EGS system at the St. Johns Dome in Eastern Arizona, including a comprehensive literature search on CO2-based geothermal technologies, background seismic study, geological information, and a study of the possible use of metal oxide heat carriers to enhance the heat capacity of sCO2. It also includes cost estimates for the project, and the reasons why the project would probably not be cost effective at the proposed location.

  17. Present-day geothermal characteristics of the Ordos Basin, western North China Craton: new findings from deep borehole steady-state temperature measurements

    Science.gov (United States)

    Gao, Peng; Qiu, Qianfeng; Jiang, Guangzheng; Zhang, Chao; Hu, Shengbiao; Lei, Yuhong; Wang, Xiangzeng

    2018-07-01

    Heat flow and associated thermal regimes are related to the tectonic evolution and geophysical properties of the lithosphere. The Ordos Basin is located in a tectonic transitional zone: areas to the east of the basin are characterized as tectonically active, while regions to the west of the basin are characterized as tectonically stable. It is of general interest to learn the geothermal characteristics of the basin in such tectonic conditions. To clarify the spatial variability of the present-day geothermal field across the basin and its implications, we report 13 terrestrial heat flow points based on the first systematic steady-state deep borehole temperature measurements in the basin. The new data together with existing data show that the geothermal gradients in the basin range from 12.6 to 42.3 °C km-1 with a mean of 27.7 ± 5.3 °C km-1; the terrestrial heat flow values range from 43.3 to 88.7 mW m-2 with a mean of 64.7 ± 8.9 mW m-2. Such values are higher than those of typical cratonic basins and lower than those of tectonically active areas. By using all these data in the basin and adjacent areas, we plot geothermal gradient and heat flow distribution maps. The maps reveal that the basin is cooling westwards and northwards. The distribution pattern of the geothermal field is consistent with the lithospheric thickness variation in the basin. This similarity suggests that the geothermal spatial variability of the Ordos Basin is mainly influenced by heat from the deep mantle. In the southeastern basin, we locate a positive geothermal anomaly caused by the convergence of heat flow in basement highs and the high radiogenic heat production. In addition, the high heat flow in the eastern basin is related to the intense uplift during the Cenozoic Era.

  18. Present-day geothermal characteristics of the Ordos Basin, western North China Craton: new findings from deep borehole steady-state temperature measurements

    Science.gov (United States)

    Gao, Peng; Qiu, Qianfeng; Jiang, Guangzheng; Zhang, Chao; Hu, Shengbiao; Lei, Yuhong; Wang, Xiangzeng

    2018-03-01

    Heat flow and associated thermal regimes are related to the tectonic evolution and geophysical properties of the lithosphere. The Ordos Basin is located in a tectonic transitional zone: areas to the east of the basin are characterized as tectonically active, while regions to the west of the basin are characterized as tectonically stable. It is of general interest to learn the geothermal characteristics of the basin in such tectonic conditions. To clarify the spatial variability of the present-day geothermal field across the basin and its implications, we report 13 terrestrial heat flow points based on the first systematic steady-state deep borehole temperature measurements in the basin. The new data together with existing data show that the geothermal gradients in the basin range from 12.6 to 42.3° C km-1 with a mean of 27.7 ± 5.3° C km-1; the terrestrial heat flow values range from 43.3 to 88.7 mW/m2 with a mean of 64.7 ± 8.9 mW/m2. Such values are higher than those of typical cratonic basins and lower than those of tectonically active areas. By using all these data in the basin and adjacent areas, we plot geothermal gradient and heat flow distribution maps. The maps reveal that the basin is cooling westward and northward. The distribution pattern of the geothermal field is consistent with the lithospheric thickness variation in the basin. This similarity suggests that the geothermal spatial variability of the Ordos Basin is mainly influenced by heat from the deep mantle. In the southeastern basin, we locate a positive geothermal anomaly caused by the convergence of heat flow in basement highs and the high radiogenic heat production. In addition, the high heat flow in the eastern basin is related to the intense uplift during the Cenozoic Era.

  19. Geothermal direct heat use: Market potential/penetration analysis for Federal Region 9

    Science.gov (United States)

    Powell, W. (Editor); Tang, K. (Editor)

    1980-01-01

    A preliminary study was made of the potential for geothermal direct heat use in Arizona, California, Hawaii, and Nevada (Federal Region 9). An analysis was made of each state to: (1) define the resource, based on the latest available data; (2) assess the potential market growth for geothermal energy; and (3) estimate the market penetration, projected to 2020. Findings of the study include the following: (1) Potentially economical hydrothermal resources exist in all four states of the Region: however, the resource data base is largely incomplete, particularly for low to moderate temperature resources. (2) In terms of beneficial heat, the total hydrothermal resource identified so far for the four states is on the order of 43 Quads, including an estimated 34 Quads of high temperature resources which are suitable for direct as well as electrical applications. (3) In California, Hawaii, and Nevada, the industrial market sector has somewhat greater potential for penetration than the residential/commercial sector. In Arizona, however, the situation is reversed, due to the collocation of two major metropolitan areas (Phoenix and Tucson) with potential geothermal resources.

  20. Geophysical survey, Paso Robles geothermal area, California, part of the resource assessment of low- and moderate-temperature geothermal resource areas in California

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, R.H.; Chase, G.W.; Youngs, L.G.

    1980-11-10

    Some general background information concerning the geology and geothermal occurrences in the Southern Coast Ranges is included, as well as the more detailed information dealing with the Paso Robles area proper. Results for two geophysical methods that have been used in the area: the ground magnetic and gravity surveys, are discussed and interpreted.

  1. Intracorneal ring segments implantation followed by same-day topography-guided PRK and corneal collagen CXL in low to moderate keratoconus.

    Science.gov (United States)

    Al-Tuwairqi, Waleed; Sinjab, Mazen M

    2013-01-01

    To evaluate the safety and efficacy of intrastromal corneal ring segments (ICRS) implantation followed by same-day topography-guided photorefractive keratectomy (PRK) and ultraviolet-A/riboflavin collagen cross-linking (CXL) in patients with low to moderate keratoconus. Patients with low to moderate keratoconus and contact lens intolerance were included in the study. All patients first underwent femtosecond laser-enabled placement of ICRS (Keraring, Mediphacos) (first step). Same-day topography-guided PRK and CXL (second step) were subsequently performed in all patients after the refraction was stable (average 6 months [range: 3 to 11 months]). Thirteen eyes from 13 patients were included in the study. Based on values before the first step and 6 months after the second step, significant improvements were noted in uncorrected distance visual acuity (0.7±0.32 logMAR vs 0.08±0.08 logMAR), corrected distance visual acuity (CDVA) (0.16±0.19 logMAR vs 0.02±0.04 log-MAR), sphere (-3.65±3.08 diopters [D] vs 0.06±1.6 D), astigmatism (-3.31±1.5 D vs -0.98±0.75 D), average K (47.28±1.99 D vs 41.42±3.22 D), and coma (2.36±1.23 μm vs 1.47±0.68 μm) (PPRK/CXL may be a reasonable option for improving visual acuity in patients with low to moderate keratoconus. Copyright 2013, SLACK Incorporated.

  2. Impact of chronic low to moderate alcohol consumption on blood lipid and heart energy profile in acetaldehyde dehydrogenase 2-deficient mice.

    Science.gov (United States)

    Fan, Fan; Cao, Quan; Wang, Cong; Ma, Xin; Shen, Cheng; Liu, Xiang-wei; Bu, Li-ping; Zou, Yun-zeng; Hu, Kai; Sun, Ai-jun; Ge, Jun-bo

    2014-08-01

    To investigate the roles of acetaldehyde dehydrogenase 2 (ALDH2), the key enzyme of ethanol metabolism, in chronic low to moderate alcohol consumption-induced heart protective effects in mice. Twenty-one male wild-type (WT) or ALDH2-knockout (KO) mice were used in this study. In each genotype, 14 animals received alcohol (2.5%, 5% and 10% in week 1-3, respectively, and 18% in week 4-7), and 7 received water for 7 weeks. After the treatments, survival rate and general characteristics of the animals were evaluated. Serum ethanol and acetaldehyde levels and blood lipids were measured. Metabolomics was used to characterize the heart and serum metabolism profiles. Chronic alcohol intake decreased the survival rate of KO mice by 50%, and significantly decreased their body weight, but did not affect those of WT mice. Chronic alcohol intake significantly increased the serum ethanol levels in both WT and KO mice, but KO mice had significantly higher serum acetaldehyde levels than WT mice. Chronic alcohol intake significantly increased the serum HDL cholesterol levels in WT mice, and did not change the serum HDL cholesterol levels in KO mice. After chronic alcohol intake, WT and KO mice showed differential heart and serum metabolism profiles, including the 3 main energy substrate types (lipids, glucose and amino acids) and three carboxylic acid cycles. Low to moderate alcohol consumption increases HDL cholesterol levels and improves heart energy metabolism profile in WT mice but not in ALDH2-KO mice. Thus, preserved ALDH2 function is essential for the protective effect of low to moderate alcohol on the cardiovascular system.

  3. Intake of Fruits and Vegetables with Low-to-Moderate Pesticide Residues Is Positively Associated with Semen-Quality Parameters among Young Healthy Men123

    Science.gov (United States)

    Gaskins, Audrey J; Williams, Paige L; Mendiola, Jaime; Levine, Hagai; Hauser, Russ; Swan, Shanna H; Chavarro, Jorge E

    2016-01-01

    Background: Numerous studies have shown that occupational or environmental pesticide exposure can affect male fertility. There is less evidence, however, regarding any potentially adverse effects of pesticide residues in foods on markers of male fertility potential. Objectives: We examined the relations between fruit and vegetable intake, considering pesticide residue status, and semen quality and serum concentrations of reproductive hormones in healthy young men. Methods: The Rochester Young Men's Study is a cross-sectional study that recruited men aged 18–22 y (n = 189) in Rochester, New York. Participants completed a questionnaire, provided a semen sample, had a blood sample drawn, and underwent a physical examination at enrollment. Semen samples were analyzed for total sperm count, sperm concentration, morphology, motility, ejaculate volume, total motile count, and total normal count. Dietary intake during the previous year was assessed by a validated food-frequency questionnaire. Fruit and vegetables were categorized as having high [Pesticide Residue Burden Score (PRBS) ≥4] or low-to-moderate (PRBS vegetable intake with semen variables and reproductive hormones while adjusting for potential confounding factors. Results: The total intake of fruit and vegetables was unrelated to semen quality. However, the intake of fruit and vegetables with low-to-moderate pesticide residues was associated with a higher total sperm count and sperm concentration, whereas the intake of fruit and vegetables with high pesticide residues was unrelated to semen quality. On average, men in the highest quartile of low-to-moderate-pesticide fruit and vegetable intake (≥2.8 servings/d) had a 169% (95% CI: 45%, 400%) higher total sperm count and a 173% (95% CI: 57%, 375%) higher sperm concentration than did men in the lowest quartile (vegetables, regardless of pesticide-residue status, was not associated with reproductive hormone concentrations. Conclusions: The consumption of fruit

  4. Geothermal flux through palagonitized tephra, Surtsey, Iceland - The Surtsey temperature-data-relay experiment via Landsat-1

    Science.gov (United States)

    Friedman, J. D.; Preble, D. M.; Jakobsson, S.

    1976-01-01

    The net geothermal flux through palagonitized basaltic tephra rims of the Surtur I and Surtur II craters at Surtsey, Iceland, in 1972, is estimated at 780 plus or minus 325 microcal/sq cm/s, indicating a decline since 1969 when a flux of 1500 microcal/sq cm/s was estimated. Heat flux in this range characterizes the postvolcanic environment on Surtsey in which the subaerial polagonitization of basaltic tephra is associated with mass transfer of hydrothermal vapor, either of meteoric or sea-water origin, only a few years after cessation of eruptive activity. The flux estimation is the result of the Surtsey data-relay experiment via Landsat-1 which was carried out in several phases. Temperature data were transmitted for a 38-day period in November and December 1972. A near-surface vertical gradient of 69.4 C/m was obtained, suggesting a mixed mechanism of heat transfer, partitioned between conduction and convection.

  5. Standard Test Method for Testing Polymeric Seal Materials for Geothermal and/or High Temperature Service Under Sealing Stress

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1985-01-01

    1.1 This test method covers the initial evaluation of (screening) polymeric materials for seals under static sealing stress and at elevated temperatures. 1.2 This test method applies to geothermal service only if used in conjunction with Test Method E 1068. 1.3 The test fluid is distilled water. 1.4 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  6. Drilling Addendum to Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Gary C.; Bacon, C. Forrest; Chapman, Rodger H.; Chase, Gordon W.; Majmundar, Hasmukhrai H.

    1981-05-01

    This addendum report presents the results of the California Division of Mines and Geology (CDMG) drilling program at Calistoga, California, which was the final geothermal-resource assessment investigation performed under terms of the second year contract (1979-80) between the U.S. Department of Energy (DOE) and the CDMG under the State Coupled Program. This report is intended to supplement information presented in CDMG's technical report for the project year, ''Resource Assessment of Low- and Moderate-Temperature Geothermal Waters in Calistoga, Napa County, California''. During the investigative phase of the CDMG's Geothermal Project, over 200 well-driller's reports were obtained from the Department of Water Resources (DWR). It was hoped that the interpretation and correlation of these logs would reveal the subsurface geology of the Upper Napa Valley and also provide a check for the various geophysical surveys that were performed in the course of the study. However, these DWR driller logs proved to be inadequate due to the brief, non-technical, and erroneous descriptions contained on the logs. As a result of the lack of useable drill-hole data, and because information was desired from,deeper horizons, it became evident that drilling some exploratory holes would be necessary in order to obtain physical evidence of the stratigraphy and aquifers in the immediate Calistoga area. Pursuant to this objective, a total of twelve sites were selected--four under jurisdiction of Napa County and eight under jurisdiction of the City of Calistoga. A moratorium is currently in existence within Napa County on most geothermal drilling, and environmental and time constraints precluded CDMG from obtaining the necessary site permits within the county. However, a variance was applied for and obtained from the City of Calistoga to allow CDMG to drill within the city limits. With this areal constraint and also funding limits in mind, six drilling sites

  7. Energy Exploitation of High-Temperature Geothermal Sources in Volcanic Areas—a Possible ORC Application in Phlegraean Fields (Southern Italy

    Directory of Open Access Journals (Sweden)

    Angelo Algieri

    2018-03-01

    Full Text Available This work aims to investigate the energy performances of small-scale Organic Rankine Cycles (ORCs for the exploitation of high temperature geothermal sources in volcanic areas. For this purpose, a thermodynamic model has been developed, and a parametric analysis has been performed that considers subcritical and transcritical configurations, and different organic fluids (isobutane, isopentane, and R245ca. The investigation illustrates the significant effect of the temperature at the entrance of the expander on the ORC behaviour and the rise in system effectiveness when the internal heat exchange (IHE is adopted. As a possible application, the analysis has focused on the active volcanic area of Phlegraean Fields (Southern Italy where high temperature geothermal reservoirs are available at shallow depths. The work demonstrates that ORC systems represent a very interesting option for exploiting geothermal sources and increasing the share of energy production from renewables. In particular, the investigation has been performed considering a 1 kg/s geothermal mass flow rate at 230 °C. The comparative analysis highlights that transcritical configurations with IHE guarantee the highest performance. Isopentane is suggested to maximise the ORC electric efficiency (17.7%, while R245ca offers the highest electric power (91.3 kWel. The selected systems are able to fulfil a significant quota of the annual electric load of domestic users in the area.

  8. Geothermal survey handbook

    Energy Technology Data Exchange (ETDEWEB)

    1974-01-01

    The objective of this handbook is to publicize widely the nature of geothermal surveys. It covers geothermal survey planning and measurement as well as measurement of thermal conductivity. Methods for the detection of eruptive areas, the measurement of radiative heat using snowfall, the measurement of surface temperature using infrared radiation and the measurement of thermal flow are described. The book also contains information on physical detection of geothermal reservoirs, the measurement of spring wells, thermographic measurement of surface heat, irregular layer surveying, air thermographics and aerial photography. Isotope measurement techniques are included.

  9. Status report on direct heat and low temperature utilization of geothermal energy in New Zealand

    International Nuclear Information System (INIS)

    Lumb, J.T.; Clelland, L.

    1990-01-01

    The Tasman Pulp and Paper Company's mill at Kawerau continues to be the dominant direct user of geothermal energy in New Zealand. Recent plant changes have increased the effectiveness of the company's use of the resource. Other uses are relatively small in scale and include air and water heating for homes, motels and other commercial and industrial premises. Commercial swimming-pool complexes and pools at hotels, motels and private homes are the other major direct users. This paper reports that overall direct use of the resource has shown a slow increase during the last five years except at Rotorua where the enforced closure of bores has led to more than 70% reduction in use

  10. Application of the error propagation theory in estimates of static formation temperatures in geothermal and petroleum boreholes

    International Nuclear Information System (INIS)

    Verma, Surendra P.; Andaverde, Jorge; Santoyo, E.

    2006-01-01

    We used the error propagation theory to calculate uncertainties in static formation temperature estimates in geothermal and petroleum wells from three widely used methods (line-source or Horner method; spherical and radial heat flow method; and cylindrical heat source method). Although these methods commonly use an ordinary least-squares linear regression model considered in this study, we also evaluated two variants of a weighted least-squares linear regression model for the actual relationship between the bottom-hole temperature and the corresponding time functions. Equations based on the error propagation theory were derived for estimating uncertainties in the time function of each analytical method. These uncertainties in conjunction with those on bottom-hole temperatures were used to estimate individual weighting factors required for applying the two variants of the weighted least-squares regression model. Standard deviations and 95% confidence limits of intercept were calculated for both types of linear regressions. Applications showed that static formation temperatures computed with the spherical and radial heat flow method were generally greater (at the 95% confidence level) than those from the other two methods under study. When typical measurement errors of 0.25 h in time and 5 deg. C in bottom-hole temperature were assumed for the weighted least-squares model, the uncertainties in the estimated static formation temperatures were greater than those for the ordinary least-squares model. However, if these errors were smaller (about 1% in time and 0.5% in temperature measurements), the weighted least-squares linear regression model would generally provide smaller uncertainties for the estimated temperatures than the ordinary least-squares linear regression model. Therefore, the weighted model would be statistically correct and more appropriate for such applications. We also suggest that at least 30 precise and accurate BHT and time measurements along with

  11. Geothermal energy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role of geothermal energy may have on the energy future of the US. The topics discussed in the chapter include historical aspects of geothermal energy, the geothermal resource, hydrothermal fluids, electricity production, district heating, process heating, geopressured brines, technology and costs, hot dry rock, magma, and environmental and siting issues

  12. The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on behaviour in 5-year-old children: a prospective cohort study on 1628 children

    DEFF Research Database (Denmark)

    Skogerbø, Åshild; Kesmodel, Ulrik Schiøler; Denny, Clark

    2013-01-01

    To examine the effects of low to moderate maternal alcohol consumption and binge drinking in early pregnancy on behaviour in children at the age of 5 years.......To examine the effects of low to moderate maternal alcohol consumption and binge drinking in early pregnancy on behaviour in children at the age of 5 years....

  13. Energy Exploitation of High-Temperature Geothermal Sources in Volcanic Areas—a Possible ORC Application in Phlegraean Fields (Southern Italy)

    OpenAIRE

    Angelo Algieri

    2018-01-01

    This work aims to investigate the energy performances of small-scale Organic Rankine Cycles (ORCs) for the exploitation of high temperature geothermal sources in volcanic areas. For this purpose, a thermodynamic model has been developed, and a parametric analysis has been performed that considers subcritical and transcritical configurations, and different organic fluids (isobutane, isopentane, and R245ca). The investigation illustrates the significant effect of the temperature at the entrance...

  14. Renewable Energy Essentials: Geothermal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Geothermal energy is energy available as heat contained in or discharged from the earth's crust that can be used for generating electricity and providing direct heat for numerous applications such as: space and district heating; water heating; aquaculture; horticulture; and industrial processes. In addition, the use of energy extracted from the constant temperatures of the earth at shallow depth by means of ground source heat pumps (GSHP) is also generally referred to as geothermal energy.

  15. Numerical modeling of the impact of temperature on the behavior of minerals in the Soultz-sous-Forêts enhanced geothermal system

    Science.gov (United States)

    Van Ngo, Viet; Lucas, Yann; Clément, Alain; Fritz, Bertrand

    2015-04-01

    Operation of the enhanced geothermal system (EGS) requires to re-inject fluid, after heat exchange at the surface to the energy production, into the geothermal reservoir. This cold re-injected fluid can cause a strong disequilibrium with the fluid and granitic rock within the geothermal reservoir and then implies the possible dissolution/precipitation of minerals. The hydrothermal alterations include the transformation of plagioclase, biotite and K-feldspar and the precipitation of various secondary minerals. The major sealing phases observed in the main fracture zones are quartz, calcite, and clay minerals. These mineralogical transformations may modify the porosity, permeability and fluid pathways of the geothermal reservoir. In the Soultz-sous-Forêts EGS (Alsace, France), the hydraulic connection between the injection well and the production well is quite poor. Therefore, understanding the impact of changes in temperature, which are caused by the re-injected fluid, on the behavior of minerals (especially for the main newly-formed minerals such as quartz, calcite and clay minerals) is a critical preliminary step for the long-term prediction of their evolution. The approach used in the present work is typically based on a geochemical code, called THERMA, which enables to calculate the changes in equilibrium constants of all primary and secondary minerals and aqueous species as a function of temperature. Our model accounted for a wide range of different mineral groups in order to make sure a large freedom for the numerical calculations. The modeling results showed that when the temperature of geothermal reservoir is cooled down, quartz, calcite, illites, galena and pyrite have tendency towards equilibrium state, which indicates that they are precipitated under the geothermal conditions. In contrast, other minerals including plagioclase, K-feldspar and biotite remained unsaturated. These behaviors of minerals were further illustrated by the Khorzinsky stability

  16. Geothermal energy utilization in Russia

    Energy Technology Data Exchange (ETDEWEB)

    Svalova, V. [Institute of Environmental Geoscience, RAS, Moscow (Russian Federation)

    2011-07-01

    Geothermal energy use is the way to clean, sustainable energy development for the world. Russia has rich high and low temperature geothermal resources and is making progress using them - mostly with low-temperature geothermal resources and heat pumps This is optimal for many regions of Russia -in the European part, in the Urals and others. Electricity is generated by some geothermal power plants (GeoPP) only in the Kamchatka Peninsula and Kuril Islands There are two possible ways of using geothermal resources, depending on the properties of thermal waters heat/power and mineral extraction. The mineral-extraction direction is basic for geothermal waters, which contain valuable components in industrial quantities The most significant deposits of thermal waters represent the brines containing from 35 up to 400 and more g/l of salts. These are the minerals of many chemical dements. (author)

  17. An overview of the Awibengkok geothermal system, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Stimac, James; Nordquist, Gregg; Suminar, Aquardi; Sirad-Azwar, Lutfhie [Chevron Geothermal Salak, Ltd., 11th Floor Sentral Senayan I, Jl. Asia Afrika No. 8, Jakarta 10270 (Indonesia)

    2008-06-15

    The Awibengkok (Salak) geothermal system is a liquid-dominated, fracture-controlled reservoir with benign chemistry and low-to-moderate non-condensable gas content. The geothermal system is hosted mainly by andesitic-to-rhyodacitic rocks, and floored by Miocene marine sedimentary rocks cut by igneous intrusions. The volcanic sequence is capped by an 8400-year-old phreatic explosion breccia, rhyolite fallout tuff (>8400 years and <40,000 years), rhyolite lavas, domes and related tuffs ({>=}40-120 ka), and dacite-to-rhyodate lavas and domes (185-280 ka) that were erupted across the eastern part of the field from NNE-trending vents controlled by a major fault. More regionally extensive basaltic-andesite to andesite volcanic centers are mostly between 180 and 1610 ka old. Surface and subsurface fault patterns, formation image logs and tracer studies indicate strongly anisotropic permeability aligned with the dominant N to NE fracture trend, dividing the field into a number of subcompartments that are locally connected by fractured aquifers and NW- and E-W-trending fractures. Shallow argillic alteration gives way with increasing depth and temperature to argillic-phyllic and propylitic zones, with the latter accounting for the bulk of the fluid produced from the geothermal system. The commercial Awibengkok reservoir is a moderate-to-high temperature (240-312 C) geothermal resource with high fracture permeability, moderate porosity (mean = 10.6%) and moderate-to-low matrix permeability (geometric mean = 0.026 md). The principal deep upflow zone, with fluid temperatures in the 275-312 C range, is located in the western part of the field. The ascending fluids move up along N- or NNE-trending structures that breach low-permeability tuff layers in the central and east-central parts of the field. Fluids in the central part of the reservoir are uniform in composition and temperature, representing the mixing of upflow and convective reflux. Fluids ascend and flow laterally to

  18. Semiannual progress report for the Idaho Geothermal Program, April 1-September 30, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Parker, J.T. (ed.)

    1982-01-01

    Modifications incorporated in the 5-MW Pilot Power Plant at Raft River Geothermal Test Site, system operational testing and maintenance activities at that plant, and the water treatment program's corrosion studies are summarized. Progress is reported on performance tests of the ORNL condenser and the direct-contact heat exchanger in the Prototype Power Plant. Production-injection tests associated with pump installation in monitor wells at Raft River are reported. Case studies conducted and publications prepared for the program of low-to moderate-temperature hydrothermal resource development are also reported. Monitoring activities and studies of the environmental program at Raft River are described and two new areas of research under the Environmental Support Injection Research Program: pressure monitoring, and dispersion studies. Progress of three successful proposers under the User-Coupled Confirmation Drilling Program is summarized. A program to encourage use of geothermal energy at Federal facilities was developed and initiated. Investigation of direct use of hydrothermal energy is reported. Progress is reported on the marketing Assistance Program, through which technical information and assistance are provided to potential users and developers of geothermal resources. Also reported is progress on DOE's Program Opportunity Notice (PON) Program demonstration projects and the Program Research and Development Announcement (PRDA) Program study projects.

  19. Geothermal spas

    International Nuclear Information System (INIS)

    Woodruff, J.L.; Takahashi, P.K.

    1990-01-01

    The spa business, part of the health and fitness industry that has sprung up in recent years, is highly successful world-wide. The most traditional type of spa is the geothermal spa, found in geothermal areas around the world. In Japan, for example, some 2,000 geothermal spas and resorts generate $6 billion annually. Hawaii has an ideal environment for geothermal spas, and several locations in the islands could supply warm mineral water for spa development. Hawaii receives about 6 million visitors annually, a high percentage of whom are familiar with the relaxing and therapeutic value of geothermal spas, virtually guaranteeing the success of this industry in Hawaii. Presently, Hawaii does not have a single geothermal spa. This paper reports that the geothermal spa business is an industry whose time has come, an industry that offers very promising investment opportunities, and one that would improve the economy while expanding the diversity of pleasurable vacation options in Hawaii

  20. Geothermal studies in China

    Science.gov (United States)

    Ji-Yang, Wang; Mo-Xiang, Chen; Ji-An, Wang; Xiao, Deng; Jun, Wang; Hsien-Chieh, Shen; Liang-Ping, Hsiung; Shu-Zhen, Yan; Zhi-Cheng, Fan; Xiu-Wen, Liu; Ge-Shan, Huang; Wen-Ren, Zhang; Hai-Hui, Shao; Rong-Yan, Zhang

    1981-01-01

    Geothermal studies have been conducted in China continuously since the end of the 1950's with renewed activity since 1970. Three areas of research are defined: (1) fundamental theoretical research on geothermics, including subsurface temperatures, terrestrial heat flow and geothermal modeling; (2) exploration for geothermal resources and exploitation of geothermal energy; and (3) geothermal studies in mines. Regional geothermal studies have been conducted recently in North China and more than 2000 values of subsurface temperature have been obtained. Temperatures at a depth of 300 m generally range from 20 to 25°C with geothermal gradients from 20 to 40°C/km. These values are regarded as an average for the region with anomalies related to geological factors. To date, 22 reliable heat flow data from 17 sites have been obtained in North China and the data have been categorized according to fault block tectonics. The average heat flow value at 16 sites in the north is 1.3 HFU, varying from 0.7 to 1.8 HFU. It is apparent that the North China fault block is characterized by a relatively high heat flow with wide variations in magnitude compared to the mean value for similar tectonic units in other parts of the world. It is suggested that although the North China fault block can be traced back to the Archaean, the tectonic activity has been strengthening since the Mesozoic resulting in so-called "reactivation of platform" with large-scale faulting and magmatism. Geothermal resources in China are extensive; more than 2000 hot springs have been found and there are other manifestations including geysers, hydrothermal explosions, hydrothermal steam, fumaroles, high-temperature fountains, boiling springs, pools of boiling mud, etc. In addition, there are many Meso-Cenozoic sedimentary basins with widespread aquifers containing geothermal water resources in abundance. The extensive exploration and exploitation of these geothermal resources began early in the 1970's. Since then

  1. CLINICAL STUDY TO EVALUATE THE VISUAL OUTCOME AND PATIENT COMFORT IN LASIK AND PHOTOREFRACTIVE KERATECTOMY IN LOW-TO-MODERATE MYOPIC ASTIGMATISM PATIENTS

    Directory of Open Access Journals (Sweden)

    Ashok Kumar P

    2017-04-01

    Full Text Available BACKGROUND To evaluate visual outcomes following LASIK and Photorefractive Keratectomy (PRK in low-to-moderate myopia and/or myopic astigmatism in age and refractive error matched eyes. MATERIALS AND METHODS Of a total 30 patients aged ≥21 years, 20 (40 eyes underwent LASIK and 10 (20 eyes underwent PRK for low-to-moderate myopia or myopic astigmatism. LASIK was performed with the Alcon wave light 500 and PRK with the alcohol application for epithelial removal. All ablations were performed using the same excimer laser system. One surgeon operated all patients by using an excimer laser (Alcon wave light 500 system. Age and refractive error matched patients were divided in two groups. Preoperative and one year postoperative uncorrected visual acuity, best corrected visual acuity and manifest refractions were recorded to compare the outcomes of both the procedures. Outcome measures to assess the patient comfort levels in both groups include postoperative pain and quality of vision. Other outcome measures to assess the wound healing includes intraoperative complications, corneal haze and corneal reepithelialisation. RESULTS Sixty eyes of 30 patients were found matched regarding age and refractive error. In PRK group, among 10 patients, 5 (50% were males and 5 (50% were females, whereas in Lasik group, males were 12 (60% and 8 (40% were female patients. Mean preoperative MRSE was -4.06 ± 1.00 Dioptres (D for LASIK versus -4.50 ± 1.25 D for PRK. Complete flap healing was achieved by postoperative day 4 in 86.9% of LASIK eyes versus complete reepithelialisation in 92.4% of PRK eyes. Using Fisher exact test, a significantly higher percentage of LASIK eyes compared to PRK eyes achieved 20/15 or better at 1 month (35.8% vs. 17.8%, P=0.031, 3 months (69.3% vs. 49.3%, P=0.004, 6 months (79.1% vs. 59.9%, P0.50 D occurred in 12.4% of LASIK eyes within the 3- and 12-month interval versus 25.7% of PRK eyes (P=0.04. Patients in both groups were happy

  2. Intake of Fruits and Vegetables with Low-to-Moderate Pesticide Residues Is Positively Associated with Semen-Quality Parameters among Young Healthy Men.

    Science.gov (United States)

    Chiu, Yu-Han; Gaskins, Audrey J; Williams, Paige L; Mendiola, Jaime; Jørgensen, Niels; Levine, Hagai; Hauser, Russ; Swan, Shanna H; Chavarro, Jorge E

    2016-05-01

    Numerous studies have shown that occupational or environmental pesticide exposure can affect male fertility. There is less evidence, however, regarding any potentially adverse effects of pesticide residues in foods on markers of male fertility potential. We examined the relations between fruit and vegetable intake, considering pesticide residue status, and semen quality and serum concentrations of reproductive hormones in healthy young men. The Rochester Young Men's Study is a cross-sectional study that recruited men aged 18-22 y (n = 189) in Rochester, New York. Participants completed a questionnaire, provided a semen sample, had a blood sample drawn, and underwent a physical examination at enrollment. Semen samples were analyzed for total sperm count, sperm concentration, morphology, motility, ejaculate volume, total motile count, and total normal count. Dietary intake during the previous year was assessed by a validated food-frequency questionnaire. Fruit and vegetables were categorized as having high [Pesticide Residue Burden Score (PRBS) ≥4] or low-to-moderate (PRBS sperm count and sperm concentration, whereas the intake of fruit and vegetables with high pesticide residues was unrelated to semen quality. On average, men in the highest quartile of low-to-moderate-pesticide fruit and vegetable intake (≥2.8 servings/d) had a 169% (95% CI: 45%, 400%) higher total sperm count and a 173% (95% CI: 57%, 375%) higher sperm concentration than did men in the lowest quartile (sperm counts in young men unselected by fertility status. This suggests that pesticide residues may modify the beneficial effects of fruit and vegetable intake on semen quality. © 2016 American Society for Nutrition.

  3. Changes in higher order aberrations after wavefront-guided PRK for correction of low to moderate myopia and myopic astigmatism: two-year follow-up.

    Science.gov (United States)

    Wigledowska-Promienska, D; Zawojska, I

    2007-01-01

    To assess efficacy, safety, and changes in higher order aberrations after wavefront-guided photorefractive keratectomy (PRK) in comparison with conventional PRK for low to moderate myopia with myopic astigmatism using a WASCA Workstation with the MEL 70 G-Scan excimer laser. A total of 126 myopic or myopic-astigmatic eyes of 112 patients were included in this retrospective study. Patients were divided into two groups: Group 1, the study group; and Group 2, the control group. Group 1 consisted of 78 eyes treated with wavefront-guided PRK. Group 2 consisted of 48 eyes treated with spherocylindrical conventional PRK. Two years postoperatively, in Group 1, 5% of eyes achieved an uncorrected visual acuity (UCVA) of 0.05; 69% achieved a UCVA of 0.00; 18% of eyes experienced enhanced visual acuity of -0.18 and 8% of -0.30. In Group 2, 8% of eyes achieved a UCVA of 0.1; 25% achieved a UCVA of 0.05; and 67% achieved a UCVA of 0.00 according to logMAR calculation method. Total higher-order root-mean square increased by a factor 1.18 for Group 1 and 1.6 for Group 2. There was a significant increase of coma by a factor 1.74 in Group 2 and spherical aberration by a factor 2.09 in Group 1 and 3.56 in Group 2. The data support the safety and effectiveness of the wavefront-guided PRK using a WASCA Workstation for correction of low to moderate refractive errors. This method reduced the number of higher order aberrations induced by excimer laser surgery and improved uncorrected and spectacle-corrected visual acuity when compared to conventional PRK.

  4. Blood pressure hyperreactivity: an early cardiovascular risk in normotensive men exposed to low-to-moderate inorganic arsenic in drinking water.

    Science.gov (United States)

    Kunrath, Julie; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Gelmann, Elyssa R; Thach, Thu-Trang; McCarty, Kathleen M; Yeckel, Catherine W

    2013-02-01

    Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic. We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania. Unexposed (n = 16) and exposed (n = 19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (> 20 mmHg) and DBP (>15 mmHg). Drinking water inorganic arsenic averaged 40.2 ± 30.4 and 1.0 ± 0.2 μg/l for the exposed and unexposed groups, respectively (P pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P = 0.035) and cold stress (73.7 vs. 37.5%; P = 0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P = 0.035). Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk.

  5. Research status of geothermal resources in China

    Science.gov (United States)

    Zhang, Lincheng; Li, Guang

    2017-08-01

    As the representative of the new green energy, geothermal resources are characterized by large reserve, wide distribution, cleanness and environmental protection, good stability, high utilization factor and other advantages. According to the characteristics of exploitation and utilization, they can be divided into high-temperature, medium-temperature and low-temperature geothermal resources. The abundant and widely distributed geothermal resources in China have a broad prospect for development. The medium and low temperature geothermal resources are broadly distributed in the continental crustal uplift and subsidence areas inside the plate, represented by the geothermal belt on the southeast coast, while the high temperature geothermal resources concentrate on Southern Tibet-Western Sichuan-Western Yunnan Geothermal Belt and Taiwan Geothermal Belt. Currently, the geothermal resources in China are mainly used for bathing, recuperation, heating and power generation. It is a country that directly makes maximum use of geothermal energy in the world. However, China’s geothermal power generation, including installed generating capacity and power generation capacity, are far behind those of Western European countries and the USA. Studies on exploitation and development of geothermal resources are still weak.

  6. Hydrogeochemical characteristics and genesis of the high-temperature geothermal system in the Tashkorgan basin of the Pamir syntax, western China

    Science.gov (United States)

    Li, Yiman; Pang, Zhonghe; Yang, Fengtian; Yuan, Lijuan; Tang, Pinghui

    2017-11-01

    High-temperature geothermal systems in China, such as those found in Tenchong and Tibet, are common. A similar system without obvious manifestations found in the Tashkorgan basin in the western Xinjiang Autonomous Region, however, was not expected. The results from borehole measurements and predictions with geothermometers, such as quartz, Na-K and Na-K-Mg, indicate that the reservoir temperature is approximately 250-260 °C. Geothermal water is high in Total Dissolved Solids (>2.5 g/L) and SiO2 content (>273 mg/L), and the water type is Cl·SO4-Na, likely resulting from water-rock interactions in the granodiorite reservoirs. Based on isotope analysis, it appears to be recharged by local precipitation and river water. Evidence from the relationships between major ions and the Cl and molar Na/Cl ratio suggests mixing between deep geothermal water and shallow cold groundwater during the upwelling process. Mixing ratios calculated by the relationship between Cl and SiO2 show that the proportion from cold end-members are 96-99% and 40-90% for riparian zone springs and geothermal water from boreholes, respectively. Active regional tectonic and Neo-tectonic movements in the Pamir syntax as well as radioactive elements in the granodiorite reservoir of the Himalayan stage provide basis for the high heat flow background (150-350 mW/m2). NNW trending fault systems intersecting with overlying NE faults provide circulation conduits with high permeability for geothermal water.

  7. Water Desalination using geothermal energy

    KAUST Repository

    Goosen, M.

    2010-08-03

    The paper provides a critical overview of water desalination using geothermal resources. Specific case studies are presented, as well as an assessment of environmental risks and market potential and barriers to growth. The availability and suitability of low and high temperature geothermal energy in comparison to other renewable energy resources for desalination is also discussed. Analysis will show, for example, that the use of geothermal energy for thermal desalination can be justified only in the presence of cheap geothermal reservoirs or in decentralized applications focusing on small-scale water supplies in coastal regions, provided that society is able and willing to pay for desalting. 2010 by the authors; licensee MDPI, Basel, Switzerland.

  8. Geothermal development plan: Maricopa county

    Energy Technology Data Exchange (ETDEWEB)

    White, D.H.

    1981-01-01

    Maricopa county is the area of Arizona receiving top priority since it contains over half of the state's population. The county is located entirely within the Basin and Range physiographic region in which geothermal resources are known to occur. Several approaches were taken to match potential users to geothermal resources. One approach involved matching some of the largest facilities in the county to nearby geothermal resources. Other approaches involved identifying industrial processes whose heat requirements are less than the average assessed geothermal reservoir temperature of 110/sup 0/C (230/sup 0/F). Since many of the industries are located on or near geothermal resources, geothermal energy potentially could be adapted to many industrial processes.

  9. Geothermal energy

    International Nuclear Information System (INIS)

    Laplaige, Ph.; Lemale, J.

    2008-01-01

    Geothermal energy is a renewable energy source which consists in exploiting the heat coming from the Earth. It covers a wide range of techniques and applications which are presented in this article: 1 - the Earth, source of heat: structure of the Earth, geodynamic model and plate tectonics, origin of heat, geothermal gradient and terrestrial heat flux; 2 - geothermal fields and resources; 3 - implementation of geothermal resources: exploration, main characteristic parameters, resource exploitation; 4 - uses of geothermal resources: power generation, thermal uses, space heating and air conditioning heat pumps, district heating, addition of heat pumps; 5 - economical aspects: power generation, heat generation for district heating; 6 - environmental aspects: conditions of implementation, impacts as substitute to fossil fuels; 7 - geothermal energy in France: resources, organisation; 8 - conclusion. (J.S.)

  10. Direct use of low temperature geothermal water by Aquafarms International, Inc. for freshwater aquaculture (prawns and associated species). An operations and maintenance manual

    Energy Technology Data Exchange (ETDEWEB)

    Broughton, R.; Price, M.; Price, V.; Grajcer, D.

    1984-04-01

    In connection with an ongoing commercial aquaculture project in the Coachella Valley, California; a twelve month prawn growout demonstration project was conducted. This project began in August, 1979 and involved the use of low temperature (85/sup 0/F) geothermal waters to raise freshwater prawns, Macrobrachium rosenbergii (deMan), in earthen ponds. The following publication is an operations and maintenance guide which may by useful for those interested in conducting similar enterprises.

  11. Geothermal energy

    International Nuclear Information System (INIS)

    Le Du, H.; Bouchot, V.; Lopez, S.; Bialkowski, A.; Colnot, A.; Rigollet, C.; Sanjuan, B.; Millot, R.; Brach, M.; Asmundsson, R.; Giroud, N.

    2010-01-01

    Geothermal energy has shown a revival for several years and should strongly develop in a near future. Its potentiality is virtually unexhaustible. Its uses are multiple and various: individual and collective space heating, heat networks, power generation, heat storage, heat exchanges etc.. Re-launched by the demand of renewable energy sources, geothermal energy has become credible thanks to the scientific works published recently which have demonstrated its economical and technical relevance. Its image to the public is changing as well. However, lot of work remains to do to make geothermal energy a real industry in France. Several brakes have to be removed rapidly which concern the noise pollution of geothermal facilities, the risk of bad results of drillings, the electricity costs etc. This dossier gives an overview of today's main research paths in the domain of geothermal energy: 1 - geothermal energy in France: historical development, surface and deep resources, ambitions of the French national energy plan (pluri-annual investment plan for heat generation, incentives, regional 'climate-air-energy' schemes), specific regulations; 2 - geothermal energy at the city scale - sedimentary basins: Ile-de-France 40 years of Dogger reservoir exploitation, potentialities of clastic reservoirs - the Chaunoy sandstones example; 3 - geothermal power generation: conventional reservoirs - the Bouillante model (Guadeloupe, French Indies); the Soultz-sous-Forets pilot plant (Bas-Rhin, France); the supercritical reservoirs - the Krafla geothermal area (Iceland). (J.S.)

  12. Effect of Curing Temperature on the Durability of Concrete under Highly Geothermal Environment

    Directory of Open Access Journals (Sweden)

    Yang Tang

    2017-01-01

    Full Text Available To determine the durability of concrete in the actual temperature and humidity of the tunnel environment, this study investigates the mechanical properties, permeability of chloride ion, relative dynamic elastic modulus, and mass loss ratio of concrete specimens cured in the temperature which varied from normal, 40, 60, 75, and 90°C, and the humidity was kept at 90% continuously. Experimental results reveal that the hot temperature curing environment may benefit early stage strength development but reduce the long-term strength. It is proved that 60°C is a critical point. At above 60°C, the strength of the concrete material and its resistance to chloride ion permeability showed a decreasing trend; however, in the appropriate temperature range, the frost resistance properties of the concrete are improved with increasing temperature.

  13. Geothermal System Extensions

    Energy Technology Data Exchange (ETDEWEB)

    Gunnerson, Jon [Boise City Corporation, ID (United States); Pardy, James J. [Boise City Corporation, ID (United States)

    2017-09-30

    This material is based upon work supported by the Department of Energy under Award Number DE-EE0000318. The City of Boise operates and maintains the nation’s largest geothermal heating district. Today, 91 buildings are connected, providing space heating to over 5.5 million square feet, domestic water heating, laundry and pool heating, sidewalk snowmelt and other related uses. Approximately 300 million gallons of 177°F geothermal water is pumped annually to buildings and institutions located in downtown Boise. The closed loop system returns all used geothermal water back into the aquifer after heat has been removed via an Injection Well. Water injected back into the aquifer has an average temperature of 115°F. This project expanded the Boise Geothermal Heating District (Geothermal System) to bring geothermal energy to the campus of Boise State University and to the Central Addition Eco-District. In addition, this project also improved the overall system’s reliability and increased the hydraulic capacity.

  14. Modelling of temperature in deep boreholes and evaluation of geothermal heat flow at Forsmark and Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan; Back, Paer-Erik; Laendell, Maerta; Sundberg, Anders (GEO INNOVA AB, Linkoeping (Sweden))

    2009-06-15

    This report presents modelling of temperature and temperature gradients in boreholes in Laxemar and Forsmark and fitting to measured temperature data. The modelling is performed with an analytical expression including thermal conductivity, thermal diffusivity, heat flow, internal heat generation and climate events in the past. As a result of the fitting procedure it is also possible to evaluate local heat flow values for the two sites. However, since there is no independent evaluation of the heat flow, uncertainties in for example thermal conductivity, diffusivity and the palaeoclimate temperature curve are transferred into uncertainties in the heat flow. Both for Forsmark and Laxemar, reasonably good fits were achieved between models and data on borehole temperatures. However, none of the general models achieved a fit within the 95% confidence intervals of the measurements. This was achieved in some cases for the additional optimised models. Several of the model parameters are uncertain. A good model fit does not automatically imply that 'correct' values have been used for these parameters. Similar model fits can be expected with different sets of parameter values. The palaeoclimatically corrected surface mean heat flow at Forsmark and Laxemar is suggested to be 61 and 56 mW/m2 respectively. If all uncertainties are combined, including data uncertainties, the total uncertainty in the heat flow determination is judged to be within +12% to -14% for both sites. The corrections for palaeoclimate are quite large and verify the need of site-specific climate descriptions. Estimations of the current ground surface temperature have been made by extrapolations from measured temperature logging. The mean extrapolated ground surface temperature in Forsmark and Laxemar is estimated to 6.5 deg and 7.3 deg C respectively. This is approximately 1.7 deg C higher for Forsmark, and 1.6 deg C higher for Laxemar compared to data in the report SKB-TR-06-23. Comparison with

  15. Modelling of temperature in deep boreholes and evaluation of geothermal heat flow at Forsmark and Laxemar

    International Nuclear Information System (INIS)

    Sundberg, Jan; Back, Paer-Erik; Laendell, Maerta; Sundberg, Anders

    2009-05-01

    This report presents modelling of temperature and temperature gradients in boreholes in Laxemar and Forsmark and fitting to measured temperature data. The modelling is performed with an analytical expression including thermal conductivity, thermal diffusivity, heat flow, internal heat generation and climate events in the past. As a result of the fitting procedure it is also possible to evaluate local heat flow values for the two sites. However, since there is no independent evaluation of the heat flow, uncertainties in for example thermal conductivity, diffusivity and the palaeoclimate temperature curve are transferred into uncertainties in the heat flow. Both for Forsmark and Laxemar, reasonably good fits were achieved between models and data on borehole temperatures. However, none of the general models achieved a fit within the 95% confidence intervals of the measurements. This was achieved in some cases for the additional optimised models. Several of the model parameters are uncertain. A good model fit does not automatically imply that 'correct' values have been used for these parameters. Similar model fits can be expected with different sets of parameter values. The palaeoclimatically corrected surface mean heat flow at Forsmark and Laxemar is suggested to be 61 and 56 mW/m 2 respectively. If all uncertainties are combined, including data uncertainties, the total uncertainty in the heat flow determination is judged to be within +12% to -14% for both sites. The corrections for palaeoclimate are quite large and verify the need of site-specific climate descriptions. Estimations of the current ground surface temperature have been made by extrapolations from measured temperature logging. The mean extrapolated ground surface temperature in Forsmark and Laxemar is estimated to 6.5 deg and 7.3 deg C respectively. This is approximately 1.7 deg C higher for Forsmark, and 1.6 deg C higher for Laxemar compared to data in the report SKB-TR-06-23. Comparison with air

  16. Thermal-permeability structure and recharge conditions of the Mutnovsky high-temperature geothermal field (Kamchatka, Russia)

    Science.gov (United States)

    Kiryukhin, A. V.; Polyakov, A. Y.; Usacheva, O. O.; Kiryukhin, P. A.

    2018-05-01

    The Mutnovsky geothermal area is part of the Eastern Kamchatka active volcano belt. Mutnovsky, 80 kY old and an aging strato-volcano (a complex of 4 composite volcanic cones), acts as a magma- and water-injector into the 25-km-long North Mutnovsky extension zone. Magmatic injection events (dykes) are associated with plane-oriented MEQ (Micro Earth Quakes) clusters, most of them occurring in the NE sector of the volcano (2 × 10 km2) at elevations from -4 to -2 km, while some magmatic injections occur at elevations from -6.0 to -4.0 km below the Mutnovsky production field. Water recharge of production reservoirs is from the Mutnovsky volcano crater glacier (+1500 to +1800 masl), which was confirmed by water isotopic data (δD, δ18O) of production wells at an earlier stage of development. The Mutnovsky (Dachny) 260-310 °C high-temperature production geothermal reservoir with a volume of 16 km3 is at the junction of NNE- and NE-striking normal faults, which coincides with the current dominant dyke injection orientation. TOUGH2-modeling estimates of the reservoir properties are as follows: the reservoir permeability is 90-600 e-15 m2, the deep upflow recharge is 80 kg/s and the enthalpy is 1420 kJ/kg. Modeling was used to reproduce the history of the Mutnovsky (Dachny) reservoir exploitation since 1983 with an effective power of 48 MWe by 2016. Modeling also showed that the reservoir is capable of yielding 65-83 MWe of sustainable production until 2055, if additional production drilling in the SE part of the field is performed. Moreover, this power value may increase to 87-105 MWe if binary technologies are applied. Modeling also shows that the predicted power is sensitive to local meteoric water influx during development. Conceptual iTOUGH2-EOS1sc thermal hydrodynamic modeling of the Mutnovsky magma-hydrothermal system as a whole reasonably explains its evolution over the last 1500-5000 years in terms of heat recharge (dyke injection from the Mutnovsky-4 funnel) and

  17. Efficacy and safety of transcatheter aortic valve replacement in aortic stenosis patients at low to moderate surgical risk: a comprehensive meta-analysis.

    Science.gov (United States)

    Elmaraezy, Ahmed; Ismail, Ammar; Abushouk, Abdelrahman Ibrahim; Eltoomy, Moutaz; Saad, Soha; Negida, Ahmed; Abdelaty, Osama Mahmoud; Abdallah, Ahmed Ramadan; Aboelfotoh, Ahmed Magdy; Hassan, Hossam Mahmoud; Elmaraezy, Aya Gamal; Morsi, Mahmoud; Althaher, Farah; Althaher, Moath; AlSafadi, Ammar M

    2017-08-24

    Recently, transcatheter aortic valve replacement (TAVR) has become the procedure of choice in high surgical risk patients with aortic stenosis (AS). However, its value is still debated in operable AS cases. We performed this meta-analysis to compare the safety and efficacy of TAVR to surgical aortic valve replacement (SAVR) in low-to-moderate surgical risk patients with AS. A systematic search of five authentic databases retrieved 11 eligible studies (20,056 patients). Relevant Data were pooled as risk ratios (RRs) or standardized mean differences (SMD), with their 95% confidence interval, using Comprehensive Meta-Analysis and RevMan software for windows. At one-year of follow-up, the pooled effect-estimates showed no significant difference between TAVR and SAVR groups in terms of all-cause mortality (RR 1.02, 95% CI [0.83, 1.26], stroke (RR 0.83, 95%CI [0.56, 1.21]), myocardial infarction (RR 0.82, 95% CI [0.57, 1.19]), and length of hospital stay (SMD -0.04, 95% CI [-0.34, 0.26]). The incidence of major bleeding (RR 0.45, 95% CI [0.24, 0.86]) and acute kidney injury (RR 0.52, 95% CI [0.30, 0.88]) was significantly lower in the TAVR group, compared to the SAVR group. However, TAVR was associated with a higher risk of permanent pacemaker implantation (RR 2.57, 95% CI [1.36, 4.86]), vascular-access complications at 1 year (RR 1.99, 95%CI [1.04, 3.80]), and paravalvular aortic regurgitation at 30 days (RR 3.90, 95% CI [1.25, 12.12]), compared to SAVR. Due to the comparable mortality rates in SAVR and TAVR groups and the lower risk of life-threatening complications in the TAVR group, TAVR can be an acceptable alternative to SAVR in low-to-moderate risk patients with AS. However, larger trials with longer follow-up periods are required to compare the long-term outcomes of both techniques.

  18. Vector analysis of low to moderate astigmatism with small incision lenticule extraction (SMILE): results of a 1-year follow-up.

    Science.gov (United States)

    Zhang, Jiamei; Wang, Yan; Wu, Wenjing; Xu, Lulu; Li, Xiaojing; Dou, Rui

    2015-01-24

    To evaluate the refractive outcomes for the correction of low to moderate astigmatism up to 1 year following small incision lenticule extraction (SMILE) surgery. This retrospective study enrolled 98 eyes from 98 patients who underwent SMILE surgery for the correction of myopia and astigmatism. Only right eyes were included in this study to avoid the bias of orientation errors. The vector method was used to analyze the outcomes of astigmatism at 1 month, 6 months and 12 months after the procedure, including the double-angle plots, correction index (CI), index of success (IOS), angle of error (AofE) and magnitude of error (MofE). The effectiveness, safety, stability and predictability were also investigated during the 12-month follow-up. The preoperative cylinder ranged from -2.75 D to -0.25 D (average of -0.90±0.68 D), and the mean postoperative cylinder values were -0.24±0.29 D, -0.24±0.29 D, and -0.20±0.27 D at 1 month, 6 months, and 12 months, respectively. The mean astigmatism in vector form was -0.14 D×27.19° at 1 month, -0.13 D×27.29° at 6 months, and -0.10 D×28.63° at 12 months after surgery. The CI was 1.00±0.32 and IOS was 0.29±0.44 at the 12-month follow-up. Significant negative correlations were found between the CI and absolute target induced astigmatism (TIA) value, and positive correlations were found between the IOS and absolute AofE value (Psafe in correcting low to moderate astigmatism, and stable refractive outcomes were observed at the long-term follow-up. The undercorrection of astigmatism could possibly be influenced by attempted astigmatism correction preoperatively, the axis rotation during the surgery or wound healing postoperatively. This study suggested that nomograms should be adjusted in correcting astigmatism with SMILE surgery.

  19. Low to Moderate Average Alcohol Consumption and Binge Drinking in Early Pregnancy: Effects on Choice Reaction Time and Information Processing Time in Five-Year-Old Children.

    Directory of Open Access Journals (Sweden)

    Tina R Kilburn

    Full Text Available Deficits in information processing may be a core deficit after fetal alcohol exposure. This study was designed to investigate the possible effects of weekly low to moderate maternal alcohol consumption and binge drinking episodes in early pregnancy on choice reaction time (CRT and information processing time (IPT in young children.Participants were sampled based on maternal alcohol consumption during pregnancy. At the age of 60-64 months, 1,333 children were administered a modified version of the Sternberg paradigm to assess CRT and IPT. In addition, a test of general intelligence (WPPSI-R was administered.Adjusted for a wide range of potential confounders, this study showed no significant effects of average weekly maternal alcohol consumption during pregnancy on CRT or IPT. There was, however, an indication of slower CRT associated with binge drinking episodes in gestational weeks 1-4.This study observed no significant effects of average weekly maternal alcohol consumption during pregnancy on CRT or IPT as assessed by the Sternberg paradigm. However, there were some indications of CRT being associated with binge drinking during very early pregnancy. Further large-scale studies are needed to investigate effects of different patterns of maternal alcohol consumption on basic cognitive processes in offspring.

  20. Low temperature geothermal systems in carbonate-evaporitic rocks: Mineral equilibria assumptions and geothermometrical calculations. Insights from the Arnedillo thermal waters (Spain).

    Science.gov (United States)

    Blasco, Mónica; Gimeno, María J; Auqué, Luis F

    2018-02-15

    Geothermometrical calculations in low-medium temperature geothermal systems hosted in carbonate-evaporitic rocks are complicated because 1) some of the classical chemical geothermometers are, usually, inadequate (since they were developed for higher temperature systems with different mineral-water equilibria at depth) and 2) the chemical geothermometers calibrated for these systems (based on the Ca and Mg or SO 4 and F contents) are not free of problems either. The case study of the Arnedillo thermal system, a carbonate-evaporitic system of low temperature, will be used to deal with these problems through the combination of several geothermometrical techniques (chemical and isotopic geothermometers and geochemical modelling). The reservoir temperature of the Arnedillo geothermal system has been established to be in the range of 87±13°C being the waters in equilibrium with respect to calcite, dolomite, anhydrite, quartz, albite, K-feldspar and other aluminosilicates. Anhydrite and quartz equilibria are highly reliable to stablish the reservoir temperature. Additionally, the anhydrite equilibrium explains the coherent results obtained with the δ 18 O anhydrite - water geothermometer. The equilibrium with respect to feldspars and other aluminosilicates is unusual in carbonate-evaporitic systems and it is probably related to the presence of detrital material in the aquifer. The identification of the expected equilibria with calcite and dolomite presents an interesting problem associated to dolomite. Variable order degrees of dolomite can be found in natural systems and this fact affects the associated equilibrium temperature in the geothermometrical modelling and also the results from the Ca-Mg geothermometer. To avoid this uncertainty, the order degree of the dolomite present in the Arnedillo reservoir has been determined and the results indicate 18.4% of ordered dolomite and 81.6% of disordered dolomite. Overall, the results suggest that this multi

  1. Production data from five major geothermal fields in Nevada analysed using a physiostatistical algorithm developed for oil and gas: temperature decline forecasts and type curves

    Science.gov (United States)

    Kuzma, H. A.; Golubkova, A.; Eklund, C.

    2015-12-01

    Nevada has the second largest output of geothermal energy in the United States (after California) with 14 major power plants producing over 425 megawatts of electricity meeting 7% of the state's total energy needs. A number of wells, particularly older ones, have shown significant temperature and pressure declines over their lifetimes, adversely affecting economic returns. Production declines are almost universal in the oil and gas (O&G) industry. BetaZi (BZ) is a proprietary algorithm which uses a physiostatistical model to forecast production from the past history of O&G wells and to generate "type curves" which are used to estimate the production of undrilled wells. Although BZ was designed and calibrated for O&G, it is a general purpose diffusion equation solver, capable of modeling complex fluid dynamics in multi-phase systems. In this pilot study, it is applied directly to the temperature data from five Nevada geothermal fields. With the data appropriately normalized, BZ is shown to accurately predict temperature declines. The figure shows several examples of BZ forecasts using historic data from Steamboat Hills field near Reno. BZ forecasts were made using temperature on a normalized scale (blue) with two years of data held out for blind testing (yellow). The forecast is returned in terms of percentiles of probability (red) with the median forecast marked (solid green). Actual production is expected to fall within the majority of the red bounds 80% of the time. Blind tests such as these are used to verify that the probabilistic forecast can be trusted. BZ is also used to compute and accurate type temperature profile for wells that have yet to be drilled. These forecasts can be combined with estimated costs to evaluate the economics and risks of a project or potential capital investment. It is remarkable that an algorithm developed for oil and gas can accurately predict temperature in geothermal wells without significant recasting.

  2. Development of geothermal resources

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This paper describes the geothermal development promotion survey project. NEDO is taking the lead in investigation and development to reduce risks for private business entities and promote their development. The program is being moved forward by dividing the surveys into three ranks of A, B and C from prospects of geothermal resource availability and the state of data accumulation. The survey A lacks number of data, but covers areas as wide as 100 to 300 km{sup 2}, and studies possible existence of high-temperature geothermal energy. The survey B covers areas of 50 to 70 km{sup 2}, investigates availability of geothermal resources, and assesses environmental impacts. The survey C covers areas of 5 to 10 km{sup 2}, and includes production well drilling and long-term discharge tests, other than those carried out by the surveys A and B. Results derived in each fiscal year are evaluated and judged to establish development plans for the subsequent fiscal year. This paper summarizes development results on 38 areas from among 45 areas surveyed since fiscal 1980. Development promotion surveys were carried out over seven areas in fiscal 1994. Development is in progress not only on utilization of high-temperature steam, but also on binary cycle geothermal power generation utilizing hot waters of 80 to 150{degree}C. Fiscal 1994 has carried out discussions for spread and practical use of the systems (particularly on economic effects), and development of small-to-medium scale binary systems. 2 figs., 1 tab.

  3. Geothermal energy

    International Nuclear Information System (INIS)

    Vuataz, F.-D.

    2005-01-01

    This article gives a general overview of the past and present development of geothermal energy worldwide and a more detailed one in Switzerland. Worldwide installed electrical power using geothermal energy sources amounts to 8900 MW el . Worldwide utilization of geothermal energy for thermal applications amounts to 28,000 MW th . The main application (56.5%) is ground-coupled heat pumps, others are thermal spas and swimming pools (17.7%), space heating (14.9%), heating of greenhouses (4.8%), fish farming (2.2%), industrial uses (1,8%), cooling and melting of snow (1.2%), drying of agricultural products (0.6 %). Switzerland has become an important user of geothermal energy only in the past 25 years. Earlier, only the exploitation of geothermal springs (deep aquifers) in Swiss thermal baths had a long tradition, since the time of the Romans. Today, the main use of geothermal energy is as a heat source for heat pumps utilizing vertical borehole heat exchangers of 50 to 350 meters length. 35,000 installations of this type with heating powers ranging from a few kW to 1000 kW already exist, representing the highest density of such installations worldwide. Other developments are geostructures and energy piles, the use of groundwater for heating and cooling, geothermal district heating, the utilization of draining water from tunnels and the project 'Deep Heat Mining' allowing the combined production of heat and electric power

  4. Utilization of geothermal energy in the mining and processing of tungsten ore. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, M.V.; Lacy, S.B.; Lowe, G.D.; Nussbaum, A.M.; Walter, K.M.; Willens, C.A.

    1981-01-01

    The engineering, economic, and environmental feasibility of the use of low and moderate temperature geothermal heat in the mining and processing of tungsten ore is explored. The following are covered: general engineering evaluation, design of a geothermal energy system, economics, the geothermal resource, the institutional barriers assessment, environmental factors, an alternate geothermal energy source, and alternates to geothermal development. (MHR)

  5. Habitual coffee and tea drinkers experienced increases in blood pressure after consuming low to moderate doses of caffeine; these increases were larger upright than in the supine posture.

    Science.gov (United States)

    McMullen, Michael K; Whitehouse, Julie M; Shine, Gillian; Towell, Anthony

    2011-04-01

    Caffeine users have been encouraged to consume caffeine regularly to maintain their caffeine tolerance and so avoid caffeine's acute pressor effects. In controlled conditions complete caffeine tolerance to intervention doses of 250 mg develops rapidly following several days of caffeine ingestion, nevertheless, complete tolerance is not evident for lower intervention doses. Similarly complete caffeine tolerance to 250 mg intervention doses has been demonstrated in habitual coffee and tea drinkers' but for lower intervention doses complete tolerance is not evident. This study investigated a group of habitual caffeine users following their self-determined consumption pattern involving two to six servings daily. Cardiovascular responses following the ingestion of low to moderate amounts caffeine (67, 133 and 200 mg) were compared with placebo in a double-blind, randomised design without caffeine abstinence. Pre-intervention and post-intervention (30 and 60 min) 90 s continuous cardiovascular recordings were obtained with the Finometer in both the supine and upright postures. Participants were 12 healthy habitual coffee and tea drinkers (10 female, mean age 36). Doses of 67 and 133 mg increased systolic pressure in both postures while in the upright posture diastolic pressure and aortic impedance increased while arterial compliance decreased. These vascular changes were larger upright than supine for 133 mg caffeine. Additionally 67 mg caffeine increased dp/dt and indexed peripheral resistance in the upright posture. For 200 mg caffeine there was complete caffeine tolerance. Cardiovascular responses to caffeine appear to be associated with the size of the intervention dose. Habitual tea and coffee drinking does not generate complete tolerance to caffeine as has been previously suggested. Both the type and the extent of caffeine induced cardiovascular changes were influenced by posture.

  6. Noninvasive Coronary Angiography using 64-Detector-Row Computed Tomography in Patients with a Low to Moderate Pretest Probability of Significant Coronary Artery Disease

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, T.; Mohrs, O.K.; Magedanz, A.; Nowak, B.; Voigtlaender, T.; Barkhausen, J.; Schmermund, A. [Dept. of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany)

    2007-04-15

    Purpose: To evaluate the value of 64-detector-row computed tomography for ruling out high-grade coronary stenoses in patients with a low to moderate pretest probability of significant coronary artery disease. Material and Methods: The study included 61 patients with a suspicion of coronary artery disease on the basis of atypical angina or ambiguous findings in noninvasive stress testing and a class II indication for invasive coronary angiography (ICA). All patients were examined by 64-detector-row computed tomography angiography (CTA) and ICA. On a coronary segmental level, the presence of significant (>50% diameter) stenoses was examined. Results: In a total of 915 segments, CTA detected 62 significant stenoses. Thirty-four significant stenoses were confirmed by ICA, whereas 28 stenoses could not be confirmed by ICA. Twenty-two of them showed wall irregularities on ICA, and six were angiographically normal. Accordingly, on a coronary segmental basis, 28 false-positive and 0 false-negative findings resulted in a sensitivity of 100%, a specificity of 96.8%, a positive predictive value of 54.8%, and a negative predictive value of 100%. The diagnostic accuracy was 96.9%. Conclusion: Sixty-four-detector-row computed tomography reliably detects significant coronary stenoses in patients with suspected coronary artery disease and appears to be helpful in the selection of patients who need to undergo ICA. Calcified and non-calcified plaques are detected. Grading of stenoses in areas with calcification is difficult. Frequently, stenosis severity is overestimated by 64-detector-row computed tomography.

  7. Noninvasive Coronary Angiography using 64-Detector-Row Computed Tomography in Patients with a Low to Moderate Pretest Probability of Significant Coronary Artery Disease

    International Nuclear Information System (INIS)

    Schlosser, T.; Mohrs, O.K.; Magedanz, A.; Nowak, B.; Voigtlaender, T.; Barkhausen, J.; Schmermund, A.

    2007-01-01

    Purpose: To evaluate the value of 64-detector-row computed tomography for ruling out high-grade coronary stenoses in patients with a low to moderate pretest probability of significant coronary artery disease. Material and Methods: The study included 61 patients with a suspicion of coronary artery disease on the basis of atypical angina or ambiguous findings in noninvasive stress testing and a class II indication for invasive coronary angiography (ICA). All patients were examined by 64-detector-row computed tomography angiography (CTA) and ICA. On a coronary segmental level, the presence of significant (>50% diameter) stenoses was examined. Results: In a total of 915 segments, CTA detected 62 significant stenoses. Thirty-four significant stenoses were confirmed by ICA, whereas 28 stenoses could not be confirmed by ICA. Twenty-two of them showed wall irregularities on ICA, and six were angiographically normal. Accordingly, on a coronary segmental basis, 28 false-positive and 0 false-negative findings resulted in a sensitivity of 100%, a specificity of 96.8%, a positive predictive value of 54.8%, and a negative predictive value of 100%. The diagnostic accuracy was 96.9%. Conclusion: Sixty-four-detector-row computed tomography reliably detects significant coronary stenoses in patients with suspected coronary artery disease and appears to be helpful in the selection of patients who need to undergo ICA. Calcified and non-calcified plaques are detected. Grading of stenoses in areas with calcification is difficult. Frequently, stenosis severity is overestimated by 64-detector-row computed tomography

  8. Geothermal heat flux in the Amundsen Sea sector of West Antarctica: New insights from temperature measurements, depth to the bottom of the magnetic source estimation, and thermal modeling

    Science.gov (United States)

    Dziadek, R.; Gohl, K.; Diehl, A.; Kaul, N.

    2017-07-01

    Focused research on the Pine Island and Thwaites glaciers, which drain the West Antarctic Ice Shelf (WAIS) into the Amundsen Sea Embayment (ASE), revealed strong signs of instability in recent decades that result from variety of reasons, such as inflow of warmer ocean currents and reverse bedrock topography, and has been established as the Marine Ice Sheet Instability hypothesis. Geothermal heat flux (GHF) is a poorly constrained parameter in Antarctica and suspected to affect basal conditions of ice sheets, i.e., basal melting and subglacial hydrology. Thermomechanical models demonstrate the influential boundary condition of geothermal heat flux for (paleo) ice sheet stability. Due to a complex tectonic and magmatic history of West Antarctica, the region is suspected to exhibit strong heterogeneous geothermal heat flux variations. We present an approach to investigate ranges of realistic heat fluxes in the ASE by different methods, discuss direct observations, and 3-D numerical models that incorporate boundary conditions derived from various geophysical studies, including our new Depth to the Bottom of the Magnetic Source (DBMS) estimates. Our in situ temperature measurements at 26 sites in the ASE more than triples the number of direct GHF observations in West Antarctica. We demonstrate by our numerical 3-D models that GHF spatially varies from 68 up to 110 mW m-2.

  9. Development of geothermal-well-completion systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, E.B.

    1979-01-01

    Results of a three year study concerning the completion of geothermal wells, specifically cementing, are reported. The research involved some specific tasks: (1) determination of properties an adequate geothermal well cement must possess; (2) thorough evaluation of current high temperature oilwell cementing technology in a geothermal context; (3) basic research concerning the chemical and physical behavior of cements in a geothermal environment; (4) recommendation of specific cement systems suitable for use in a geothermal well.

  10. Techno-Economic Analysis of Integration of Low-Temperature Geothermal Resources for Coal-Fired Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Bearden, Mark D.; Davidson, Casie L.; Horner, Jacob A.; Heldebrant, David J.; Freeman, Charles J.

    2016-05-11

    Presented here are the results of a techno-economic (TEA) study of the potential for coupling low-grade geothermal resources to boost the electrical output from coal-fired power plants. This study includes identification of candidate 500 MW subcritical coal-fired power plants in the continental United States, followed by down-selection and characterization of the North Valmy generating station, a Nevada coal-fired plant. Based on site and plant characteristics, ASPEN Plus models were designed to evaluate options to integrate geothermal resources directly into existing processes at North Valmy. Energy outputs and capital costing are presented for numerous hybrid strategies, including integration with Organic Rankine Cycles (ORCs), which currently represent the primary technology for baseload geothermal power generation.

  11. Geothermal energy

    International Nuclear Information System (INIS)

    Lemale, J.

    2009-01-01

    The geothermal energy, listed among the new and renewable energy sources, is characterized by a huge variety of techniques and applications. This book deals with the access to underground geothermal resources and with their energy valorization as well. After a presentation of the main geological, hydrogeological and thermal exploitation aspects of this resource, the book presents the different geothermal-related industries in detail, in particular the district heating systems, the aquifer-based heat pumps, the utilizations in the agriculture, fishery and balneology sectors, and the power generation. (J.S.)

  12. Geothermal investigations in Slovenia

    Directory of Open Access Journals (Sweden)

    Danilo Ravnik

    1991-12-01

    Full Text Available The paper presents the methodology and the results of geothermal investigations, based on seventy-two boreholes in the territory of the Republic of Slovenia.The data of fundamental geothermal quantities: formation temperature, thermal conductivity, and radiogenic heat production of rocks as well as surface heat flow density are stored in a computerized data base. Their synthesis is given in the map of formation temperatures at 1000 m depth and in the map of surface heat flow density. In both maps the thermal difference between the Pannonian basin in theeastern and the Dinarides in the western part of Slovenia is clearly expressed.However, in the boundary area between these two tectonic units, for a distance of about 100 km in SW-NE direction, elevated horizontal gradients of formation temperature as well as heat flow density are evident. A small positive thermal anomaly in the Ljubljana depression is conspicuous.The low-temperature geothermal resources in Slovenia such as thermalsprings and thermal water from boreholes, are estimated to have a flow rate of 1120 kg/s, corresponding to the ideal total heat production of 144 MWt. In the geothermally promising areas amounting to 3200 km2 the rate of accessible resource base (ARB down to the depth of 3 km has been assessed to about 8.5 x lO 20» J.

  13. Geophysical considerations of geothermics

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, M

    1967-01-01

    The development and utilization of geothermal energy is described from the standpoint of geophysics. The internal temperature of the Earth and the history and composition of magmas are described. Methods of exploration such as gravity, magnetic, thermal and electrical surveys are discussed, as are geochemical and infrared photogrammetric techniques. Examples are provided of how these techniques have been used in Italy and at the Matsukawa geothermal field in Japan. Drilling considerations such as muds, casings and cementing materials are discussed. Solutions are proposed for problems of environmental pollution and plant expansion.

  14. Victorian first for geothermal

    International Nuclear Information System (INIS)

    Wallace, Paula

    2014-01-01

    AGL Limited (AGL) will assist Maroondah Sports Club to save hundreds of thousands of dollars on its energy bills over the next decade by commencing work to install Victoria's first GeoAir geothermal cooling and heating system. Utilising the earth's constant temperature, the new GeoAir geothermal system provides a renewable source of energy that will save the club up to $12,000 in the first year and up to $150,000 over the next 10 years

  15. Geothermal Field Investigations of Turkey

    Science.gov (United States)

    Sayın, N.; Özer, N.

    2017-12-01

    Geothermal energy is a type of energy that are found in the accessible depth of the crust, in the reservoirs by way of the permeable rocks, specially in heated fluid. Geothermal system is made of 3 main components; heat source, reservoir, and fluid bearing heat. Geothermal system mechanism is comprise of fluid transmission. Convection current (heat transmission) is caused by heating and causes the fluid in the system to expand. Heated fluid with low density show tendency to rise in system. Geothermal system occurs with variable geophysics and geochemical properties. Geophysical methods can determine structural properties of shallow and deep reservoirs with temperature, mineralization, gas amount, fluid movement, faulting, and sudden change in lithostratigraphic strata. This study revealed possible reservoir structures and showed examples of geophysics and gas measuring results in Turkey which is wealthy in regard to Geothermal sources.

  16. Geothermal energy technology

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    Geothermal energy research and development by the Sunshine Project is subdivided into five major categories: exploration and exploitation technology, hot-water power generation technology, volcanic power generation technology, environmental conservation and multi-use technology, and equipment materials research. The programs are being carried out by various National Research Institutes, universities, and private industry. During 1976 and 1977, studies were made of the extent of resources, reservoir structure, ground water movement, and neotectonics at the Onikobe and Hachimantai geothermal fields. Studies to be performed in the near future include the use of new prospecting methods, including artificial magnetotellurics, heat balance calculation, brightspot techniques, and remote sensing, as well as laboratory studies of the physical, mechanical, and chemical properties of rock. Studies are continuing in the areas of ore formation in geothermal environments, hot-dry-rock drilling and fracturing, large scale prospecting technology, high temperature-pressure drilling muds and well cements, and arsenic removal techniques.

  17. INTEGRATED EXPLORATION OF GEOTHERMAL RESOURCES

    Directory of Open Access Journals (Sweden)

    A. B. Alkhasov

    2016-01-01

    Full Text Available The aim. The aim is to develop the energy efficient technologies to explore hydro geothermal resources of different energy potential.Methods. Evaluation of the effectiveness of the proposed technologies has been carried out with the use of physical and mathematical, thermodynamic and optimization methods of calculation and the physical and chemical experimental research.Results. We propose the technology of integrated exploration of low-grade geothermal resources with the application of heat and water resource potential on various purposes. We also argue for the possibility of effective exploration of geothermal resources by building a binary geothermal power plant using idle oil and gas wells. We prove the prospect of geothermal steam and gas technologies enabling highly efficient use of thermal water of low energy potential (80 - 100 ° C degrees to generate electricity; the prospects of complex processing of high-temperature geothermal brine of Tarumovsky field. Thermal energy is utilized in a binary geothermal power plant in the supercritical Rankine cycle operating with a low-boiling agent. The low temperature spent brine from the geothermal power plant with is supplied to the chemical plant, where the main chemical components are extracted - lithium carbonate, magnesium burning, calcium carbonate and sodium chloride. Next, the waste water is used for various water management objectives. Electricity generated in the binary geothermal power plant is used for the extraction of chemical components.Conclusions. Implementation of the proposed technologies will facilitate the most efficient development of hydro geothermal resources of the North Caucasus region. Integrated exploration of the Tarumovsky field resources will fully meet Russian demand for lithium carbonate and sodium chloride.

  18. Effects of natural increase in temperature on clay formations and determination of the course and the effects of geothermal fluids

    International Nuclear Information System (INIS)

    Polizzano, C.; Benvegnu, F.; Giannotti, G.; Brandimarte, U.

    1986-01-01

    The behaviour of clay cover towards the geothermal fluids rising up to the surface may represent an excellent natural analogue of the potential migration processes from deep waste repositories in clay formations. The ENEA is conducting research in an appropriate area near M. Amiata in southern Tuscany in order to contribute to solving the problem of the expected impermeability of clay formations. Geothermal fields may namely give an opportunity of studying a case of clay behaviour at a scale corresponding to size and time considered in waste disposal. In the considered area a relevant geothermal field is still active. A clay complex represents the impermeable cover of the local geothermal field. Several endogenous phenomena indicate the preferential ways of migrations of fluids from the basement throughout the cover. The data obtained by the present research prove that the upward flow of fluids, is possible only in the points of reduced thickness of the cover where very important faulting or granulometric discontinuity occur. This situation typically occurs at the border and not in the central part of the clay basins

  19. Matched population comparison of visual outcomes and patient satisfaction between 3 modalities for the correction of low to moderate myopic astigmatism

    Directory of Open Access Journals (Sweden)

    Ganesh S

    2017-07-01

    Full Text Available Sri Ganesh, Sheetal Brar, Archana Pawar Phacorefractive Department, Nethradhama Superspeciality Eye Hospital, Bengaluru, Karnataka, India Purpose: To compare toric implantable collamer lens (T-ICL, femto-LASIK, and ReLEx SMILE for the treatment of low to moderate myopic astigmatism in terms of long-term visual and refractive outcomes and predictability of astigmatic correction.Materials and methods: The study included 30 eyes from 30 patients between the age groups of 21 and 40 years, undergoing bilateral surgery with any of the three procedures – T-ICL, femto-LASIK, or ReLEx SMILE – for correction of myopic astigmatism within the range of −3 to −8 D spherical equivalent (SE, with a minimum astigmatism of −0.75 D. Patients were followed up at day 1, 1 month, 6 months, and 1 year.Results: At 1 year, the mean cylinder reduced to −0.21±0.28, −0.17±0.36, and −0.22±0.28 D in the T-ICL, femto-LASIK, and ReLEx SMILE group, respectively. The predictability of astigmatism correction was comparable, with no statistically significant difference between the 3 groups (P>0.05. A total of 97% of eyes in ReLEx SMILE achieved a uncorrected distance visual acuity of 20/20 or better, compared to T-ICL (93% and FS-LASIK (90%. However, gain in lines of corrected distant visual acuity (CDVA was maximum in T-ICL group (60%. Four eyes in the femto-LASIK group had loss of CDVA by one line. Three eyes required exchange due to high vault and rotation of the T-ICL, which did not affect the final outcome.Conclusion: All 3 modalities were effective for myopic astigmatism at the end of 1 year. Quality of vision and patient satisfaction with T-ICL and ReLEx SMILE were similar and better than FS-LASIK. However, slight chances of postoperative rotation and exchange exist with T-ICL, which warrant thorough preoperative planning. Keywords: toric implantable collamer lens, femtosecond LASIK, ReLEx SMILE, myopic astigmatism

  20. Geothermal handbook

    Science.gov (United States)

    1976-01-01

    The Bureau of Land Management offered over 400,000 hectares (one million acres) for geothermal exploration and development in 1975, and figure is expected to double this year. The Energy Research and Development Administration hopes for 10-15,000 megawatts of geothermal energy by 1985, which would require, leasing over 16.3 million hectares (37 million acres) of land, at least half of which is federal land. Since there is an 8 to 8-1/2 year time laf between initial exploration and full field development, there would have to be a ten-fold increase in the amount of federal land leased within the next three years. Seventy percent of geothermal potential, 22.3 million hectares (55 million acres), is on federal lands in the west. The implication for the Service are enormous and the problems immediate. Geothermal resource are so widespread they are found to some extent in most biomes and ecosystems in the western United States. In most cases exploitation and production of geothermal resources can be made compatible with fish and wildlife management without damage, if probable impacts are clearly understood and provided for before damage has unwittingly been allowed to occur. Planning for site suitability and concern with specific operating techniques are crucial factors. There will be opportunities for enhancement: during exploration and testing many shallow groundwater bodies may be penetrated which might be developed for wildlife use. Construction equipment and materials needed for enhancement projects will be available in areas heretofore considered remote projects will be available in areas heretofore considered remote by land managers. A comprehensive knowledge of geothermal development is necessary to avoid dangers and seize opportunities. This handbook is intended to serve as a working tool in the field. It anticipated where geothermal resource development will occur in the western United States in the near future. A set of environmental assessment procedures are

  1. Overview of Resources for Geothermal Absorption Cooling for Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gluesenkamp, Kyle R [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mehdizadeh Momen, Ayyoub [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-06-01

    This report summarizes the results of a literature review in three areas: available low-temperature/coproduced geothermal resources in the United States, energy use for space conditioning in commercial buildings, and state of the art of geothermal absorption cooling.

  2. Arsenic Exposure From Drinking Water and the Incidence of CKD in Low to Moderate Exposed Areas of Taiwan: A 14-Year Prospective Study.

    Science.gov (United States)

    Hsu, Ling-I; Hsieh, Fang-I; Wang, Yuan-Hung; Lai, Tai-Shuan; Wu, Meei-Maan; Chen, Chien-Jen; Chiou, Hung-Yi; Hsu, Kuang-Hung

    2017-12-01

    Arsenic exposure is associated with decreased kidney function. The association between low to moderate arsenic exposure and kidney disease has not been fully clarified. The association between arsenic exposure from drinking water and chronic kidney disease (CKD) was examined in a long-term prospective observational study. 6,093 participants 40 years and older were recruited from arseniasis-endemic areas in northeastern Taiwan. Arsenic levels were 28.0, 92.8, and 295.7μg/L at the 50th, 75th, and 90th percentiles, respectively. Well-water arsenic and urinary total arsenic (inorganic plus methylated arsenic species) concentrations, adjusted for urinary creatinine concentration. Kidney diseases (ICD-9 codes: 250.4, 274.1, 283.11, 403.*1, 404.*2, 404.*3, 440.1, 442.1, 447.3, or 580-589) and CKD (ICD-9 code: 585) ascertained using Taiwan's National Health Insurance database 1998 to 2011. HRs contrasting CKD risk across arsenic exposure levels were estimated using Cox regression. Prevalence ORs for proteinuria (protein excretion ≥ 200mg/g) comparing quartiles of total urinary arsenic concentrations were estimated using logistic regression. We identified 1,104 incident kidney disease cases, including 447 CKD cases (incidence rates, 166.5 and 67.4 per 10 4 person-years, respectively). A dose-dependent association between well-water arsenic concentrations and kidney diseases was observed after adjusting for age, sex, education, body mass index, cigarette smoking, alcohol consumption, and analgesic use. Using arsenic concentration ≤ 10.0μg/L as reference, multivariable-adjusted HRs for incident CKD were 1.12 (95% CI, 0.88-1.42), 1.33 (95% CI, 1.03-1.72), and 1.33 (95% CI, 1.00-1.77) for arsenic concentrations of 10.1 to 49.9, 50.0 to 149.9, and ≥150.0μg/L, respectively (P for trend=0.02). The association between arsenic concentration and kidney diseases was stronger for women (P for interaction=0.06). Arsenic values in the range of 50th to 75th and 75th to 100th

  3. Temperature-induced impacts on groundwater quality and arsenic mobility in anoxic aquifer sediments used for both drinking water and shallow geothermal energy production.

    Science.gov (United States)

    Bonte, Matthijs; van Breukelen, Boris M; Stuyfzand, Pieter J

    2013-09-15

    Aquifers used for the production of drinking water are increasingly being used for the generation of shallow geothermal energy. This causes temperature perturbations far beyond the natural variations in aquifers and the effects of these temperature variations on groundwater quality, in particular trace elements, have not been investigated. Here, we report the results of column experiments to assess the impacts of temperature variations (5°C, 11°C, 25°C and 60°C) on groundwater quality in anoxic reactive unconsolidated sandy sediments derived from an aquifer system widely used for drinking water production in the Netherlands. Our results showed that at 5 °C no effects on water quality were observed compared to the reference of 11°C (in situ temperature). At 25°C, As concentrations were significantly increased and at 60 °C, significant increases were observed pH and DOC, P, K, Si, As, Mo, V, B, and F concentrations. These elements should therefore be considered for water quality monitoring programs of shallow geothermal energy projects. No consistent temperature effects were observed on Na, Ca, Mg, Sr, Fe, Mn, Al, Ba, Co, Cu, Ni, Pb, Zn, Eu, Ho, Sb, Sc, Yb, Ga, La, and Th concentrations, all of which were present in the sediment. The temperature-induced chemical effects were probably caused by (incongruent) dissolution of silicate minerals (K and Si), desorption from, and potentially reductive dissolution of, iron oxides (As, B, Mo, V, and possibly P and DOC), and mineralisation of sedimentary organic matter (DOC and P). Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Exergo-economic evaluation of electricity generation by the medium temperature geothermal resources, using a Kalina cycle: Simav case study

    International Nuclear Information System (INIS)

    Oguz, Arslan

    2010-01-01

    Abstract Recent technical developments have made it possible to generate electricity from geothermal resources with low and medium enthalpy. One of these technologies is the Kalina Cycle System (KCS-34). In this study, electricity generation from Simav geothermal field is investigated. The optimum operating conditions for the KCS-34 plant design are determined on the basis of the exergetic and life-cycle-cost concepts. With the best design, power generation of 41.2 MW and electricity production of 346.1 GWh/a can be obtained with an energetic efficiency of 14.9% and exergetic efficiency of 36.2%. It is shown that, with the currently prevailing interest and inflation rates, the plant designs considered are economically feasible for values of the present worth factor (PWF) higher than 6. (author)

  5. Low temperature geothermal energy applications in the Albuquerque area. Final report, July 1, 1978-August 18, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Kauffman, D.; Houghton, A.V.

    1979-01-01

    A study was made of the engineering and economic feasibility of hot water geothermal energy applications in the Albuquerque area. A generalized system design was developed and used as the basis for a series of economic case studies. Reservoir and user siting considerations were studied in light of the economic findings. Several specific potential applications were identified, including university campuses, industrial and commercial facilities, and residential buildings. Specific key technical problems relating to Albuquerque area applications were studied. These included environmental impacts, corrosion, scaling, heat losses in wells and transmission lines, heat exchangers, control systems, and system utilization and reliability. It is concluded that geothermal energy could be competitive with other energy sources for space heating and limited industrial use for moderate to large (10 million Btu/hr or more) energy using systems.

  6. Mental Health in Low-to-Moderate Risk Preterm, Low Birth Weight, and Small for Gestational Age Children at 4 to 5 Years: The Role of Early Maternal Parenting

    Science.gov (United States)

    Westrupp, Elizabeth M.; Mensah, Fiona K.; Giallo, Rebecca; Cooklin, Amanda; Nicholson, Jan M.

    2012-01-01

    Objectives: The majority of children born preterm, with low birth weight, or small for gestational age are born with low-to-moderate risk (LTM), yet most research focuses on the high-risk group. Little is known about whether children with LTM perinatal risk are at greater risk for mental health problems, or what the role of early maternal…

  7. Study deep geothermal energy; Studie dypgeotermisk energi

    Energy Technology Data Exchange (ETDEWEB)

    Havellen, Vidar; Eri, Lars Sigurd; Andersen, Andreas; Tuttle, Kevin J.; Ruden, Dorottya Bartucz; Ruden, Fridtjof; Rigler, Balazs; Pascal, Christophe; Larsen, Bjoern Tore

    2012-07-01

    The study aims to analyze the potential energy with current technology, challenges, issues and opportunities for deep geothermal energy using quantitative analysis. It should especially be made to identify and investigate critical connections between geothermal potential, the size of the heating requirements and technical solutions. Examples of critical relationships may be acceptable cost of technology in relation to heating, local geothermal gradient / drilling depth / temperature levels and profitability. (eb)

  8. 1978 annual report, INEL geothermal environmental program

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, S.G.; Sullivan, J.F.; Stanley, N.E.

    1979-04-01

    The objective of the Raft River Geothermal Environmental Program, in its fifth year, is to characterize the beneficial and detrimental impacts resulting from the development of moderate-temperature geothermal resources in the valley. This report summarizes the monitoring and research efforts conducted as part of this program in 1978. The results of these monitoring programs will be used to determine the mitigation efforts required to reduce long-term impacts resulting from geothermal development.

  9. Very low energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Very low energy geothermics correspond to temperatures below 30 C and has been developed to cover heating and cooling needs of recent individual houses or tertiary industries using heat pumps and low depth aquifers (<100 m). Geothermal heat pumps industry has made great strides in European Northern countries, China, Japan and the United States of America. Geothermal heat pumps are less energy consuming than air heat pumps and require less cooling fluid and maintenance. The Aquapac procedure has been developed in France in 1983 by the AFME (French Energy Control Agency), EdF and the BRGM (Geologic and Mining Research Office) to encourage the use of geothermal heat pump for domestic and sanitary water heating and to make a survey of low-depth aquifers in the whole french territory. The decay of energy costs that started in 1986 has led to a loss of interest for the Aquapac procedure, even in the tertiary industries for which the air-conditioning demand is growing up. (J.S.). 1 tab

  10. A reverse method to estimate initial temperatures in geothermal reservoirs; Un metodo inverso para estimacion de la temperatura inicial de yacimientos geotermicos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx; Ramos Alcantara, Jose R. [Centro Nacional de Investigacion y Desarrollo Tecnologico, Departamento de Ingenieria Mecanica, Cuernavaca, Morelos (Mexico); Arellano Gomez, Victor M. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)

    2010-01-15

    A method is presented for estimating the initial temperature in geothermal-reservoir formations. The method is based on control theory where the measured temperatures or temperature logs are compared with corresponding simulated temperatures for different times with the well closed. The comparison is made using a control algorithm that makes changes to the originally assumed reservoir temperatures and performs iterations until the best fit between the temperature logs and the simulated temperatures is obtained. The simulation of fluid transport and heat in the well includes the processes of circulation and stop in the presence of circulation losses, modeled on macroscopic balances of momentum and energy. The transport processes in the formation regard the reservoir as an isotropic porous medium and fluid flow is described by Darcy's law. This model generates the fields of temperatures, pressures and speeds as a function of time and space. The method was tested with data from well LV-3 in Las Tres Virgenes geothermal field, Baja California Sur, Mexico. The estimated temperatures of the undisturbed formation-or initial temperatures-are compared within {+-}15 degrees Celsius with the measured temperatures, which is an acceptable outcome from an engineering point of view. [Spanish] Se presenta un metodo para la estimacion de la temperatura inicial en las formaciones de yacimientos geotermicos. El metodo se basa en la teoria de control donde las temperaturas medidas o registros de temperatura se comparan con las correspondientes temperaturas simuladas a diferentes tiempos con el pozo cerrado. La comparacion se hace usando un algoritmo de control el cual hace cambios a las temperaturas de yacimiento originalmente supuestas y realiza iteraciones hasta que se obtiene el mejor ajuste entre los registros de temperatura y las temperaturas simuladas. La simulacion del transporte de fluidos y calor en el pozo incluye los procesos de circulacion y paro en presencia de

  11. Geothermal well log interpretation state of the art. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1980-01-01

    An in-depth study of the state of the art in Geothermal Well Log Interpretation has been made encompassing case histories, technical papers, computerized literature searches, and actual processing of geothermal wells from New Mexico, Idaho, and California. A classification scheme of geothermal reservoir types was defined which distinguishes fluid phase and temperature, lithology, geologic province, pore geometry, salinity, and fluid chemistry. Major deficiencies of Geothermal Well Log Interpretation are defined and discussed with recommendations of possible solutions or research for solutions. The Geothermal Well Log Interpretation study and report has concentrated primarily on Western US reservoirs. Geopressured geothermal reservoirs are not considered.

  12. Deep geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The hot-dry-rocks located at 3-4 km of depth correspond to low permeable rocks carrying a large amount of heat. The extraction of this heat usually requires artificial hydraulic fracturing of the rock to increase its permeability before water injection. Hot-dry-rocks geothermics or deep geothermics is not today a commercial channel but only a scientific and technological research field. The Soultz-sous-Forets site (Northern Alsace, France) is characterized by a 6 degrees per meter geothermal gradient and is used as a natural laboratory for deep geothermal and geological studies in the framework of a European research program. Two boreholes have been drilled up to 3600 m of depth in the highly-fractured granite massif beneath the site. The aim is to create a deep heat exchanger using only the natural fracturing for water transfer. A consortium of german, french and italian industrial companies (Pfalzwerke, Badenwerk, EdF and Enel) has been created for a more active participation to the pilot phase. (J.S.). 1 fig., 2 photos

  13. Geothermal Permeability Enhancement - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Joe Beall; Mark Walters

    2009-06-30

    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  14. Engineered Geothermal System Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Petty, Susan

    2014-06-19

    In June 2009, AltaRock Energy began field work on a project supported by the U.S. Department of Energy entitled “Use of Multiple Stimulations to Improve Economics of Engineered Geothermal Systems in Shallow High Temperature Intrusives.” The goal of the project was to develop an Engineered Geothermal System (EGS) in the portion of The Geysers geothermal field operated by the Northern California Power Agency (NCPA). The project encountered several problems while deepening Well E-7 which culminated in the suspension of field activities in September 2009. Some of the problems encountered are particular to The Geysers area, while others might be encountered in any geothermal field, and they might be avoided in future operations.

  15. Geothermal development plan: Maricopa County

    Energy Technology Data Exchange (ETDEWEB)

    White, D.H.; Goldstone, L.A.

    1982-08-01

    The Maricopa County Geothermal Development Plan evaluated the market potential for utilizing geothermal energy. The study identified six potential geothermal resource areas with temperatures less than 100{sup 0}C (212{sup 0}F) and in addition, four suspected intermediate temperature areas (90{sup 0} to 150{sup 0}C, 194{sup 0} to 300{sup 0}F). Geothermal resources are found to occur in and near the Phoenix metropolitan area where average population growth rates of two to three percent per year are expected over the next 40 years. Rapid growth in the manufacturing, trade and service sectors of the regional economy provides opportunities for the direct utilization of geothermal energy. A regional energy use analysis is included containing energy use and price projections. Water supplies are found to be adequate to support this growth, though agricultural water use is expected to diminish. The study also contains a detailed section matching geothermal resources to potential users. Two comparative analyses providing economic details for space heating projects are incorporated.

  16. Assessing geothermal energy potential in upstate New York. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, D.S. [SUNY, Buffalo, NY (United States)

    1996-08-01

    The potential of geothermal energy for future electric power generation in New York State is evaluated using estimates of temperatures of geothermal reservoir rocks. Bottom hole temperatures from over 2000 oil and gas wells in the region were integrated into subsurface maps of the temperatures for specific geothermal reservoirs. The Theresa/Potsdam formation provides the best potential for extraction of high volumes of geothermal fluids. The evaluation of the Theresa/Potsdam geothermal reservoir in upstate New York suggests that an area 30 miles east of Elmira, New York has the highest temperatures in the reservoir rock. The Theresa/Potsdam reservoir rock should have temperatures about 136 {degrees}C and may have as much as 450 feet of porosity in excess of 8%. Estimates of the volumes of geothermal fluids that can be extracted are provided and environmental considerations for production from a geothermal well is discussed.

  17. Geothermal tomorrow 2008

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    Contributors from the Geothermal Technologies Program and the geothermal community highlight the current status and activities of the Program and the development of the global resource of geothermal energy.

  18. Geothermal well log interpretation midterm report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1979-02-01

    Reservoir types are defined according to fluid phase and temperature, lithology, geologic province, pore geometry, and salinity and fluid chemistry. Improvements are needed in lithology and porosity definition, fracture detection, and thermal evaluation for more accurate interpretation. Further efforts are directed toward improving diagnostic techniques for relating rock characteristics and log response, developing petrophysical models for geothermal systems, and developing thermal evaluation techniques. The Geothermal Well Log Interpretation study and report has concentrated only on hydrothermal geothermal reservoirs. Other geothermal reservoirs (hot dry rock, geopressured, etc.) are not considered.

  19. Geothermal heat; Energie aus der Tiefe. Geothermie

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Karl

    2012-09-15

    The temperature in the interior of the earth increases with the depth. But for a long time, the geothermal energy only could be used at selected locations. Therefore, almost all major geothermal power plants are located at volcanic regions. The potential of the geothermal energy is not exhausted. Currently, many new power plants are developed. Although there is no volcanic activity in Germany, also some pilot plants develop the hot surface. The deep geothermal energy sometimes is difficult to be controlled. Before drilling experts rarely know how productive the subsoil is. Also, the drillings may trigger small earthquakes.

  20. Geothermal probabilistic cost study

    Energy Technology Data Exchange (ETDEWEB)

    Orren, L.H.; Ziman, G.M.; Jones, S.C.; Lee, T.K.; Noll, R.; Wilde, L.; Sadanand, V.

    1981-08-01

    A tool is presented to quantify the risks of geothermal projects, the Geothermal Probabilistic Cost Model (GPCM). The GPCM model is used to evaluate a geothermal reservoir for a binary-cycle electric plant at Heber, California. Three institutional aspects of the geothermal risk which can shift the risk among different agents are analyzed. The leasing of geothermal land, contracting between the producer and the user of the geothermal heat, and insurance against faulty performance are examined. (MHR)

  1. Honey Lake Geothermal Project, Lassen County, California

    Science.gov (United States)

    1984-11-01

    The drilling, completion, and testing of deep well WEN-2 for a hybrid electric power project which will use the area's moderate temperature geothermal fluids and locally procured wood fuel is reported. The project is located within the Wendel-Amedee Known Geothermal Resource Area.

  2. Standard Practice for Installation, Inspection, and Maintenance of Valve-body Pressure-relief Methods for Geothermal and Other High-Temperature Liquid Applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This practice covers installation, inspection, and maintenance of valve body cavity pressure relief methods for valves used in geothermal and other high-temperature liquid service. The valve type covered by this practice is a design with an isolated body cavity such that when the valve is in either the open or closed position pressure is trapped in the isolated cavity, and there is no provision to relieve the excess pressure internally. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  3. Performance comparison and parametric optimization of subcritical Organic Rankine Cycle (ORC) and transcritical power cycle system for low-temperature geothermal power generation

    International Nuclear Information System (INIS)

    Shengjun, Zhang; Huaixin, Wang; Tao, Guo

    2011-01-01

    Research highlights: → We conduct the thermodynamic and economic performance comparison of the fluids in both subcritical ORC and transcritical power cycle. → We perform parameter optimization based on five indicators. → The optimum operation parameters and working fluids are not the same for different indicators. → The LEC value is used as the determining factor for fluids screening. → The transcritical power cycle with R125 as the working fluid was a cost-effective approach. - Abstract: Organic Rankine Cycle (ORC) is a promising technology for converting the low-grade energy to electricity. This paper presents an investigation on the parameter optimization and performance comparison of the fluids in subcritical ORC and transcritical power cycle in low-temperature (i.e. 80-100 o C) binary geothermal power system. The optimization procedure was conducted with a simulation program written in Matlab using five indicators: thermal efficiency, exergy efficiency, recovery efficiency, heat exchanger area per unit power output (APR) and the levelized energy cost (LEC). With the given heat source and heat sink conditions, performances of the working fluids were evaluated and compared under their optimized internal operation parameters. The optimum cycle design and the corresponding operation parameters were provided simultaneously. The results indicate that the choice of working fluid varies the objective function and the value of the optimized operation parameters are not all the same for different indicators. R123 in subcritical ORC system yields the highest thermal efficiency and exergy efficiency of 11.1% and 54.1%, respectively. Although the thermal efficiency and exergy efficiency of R125 in transcritical cycle is 46.4% and 20% lower than that of R123 in subcritical ORC, it provides 20.7% larger recovery efficiency. And the LEC value is relatively low. Moreover, 22032L petroleum is saved and 74,019 kg CO 2 is reduced per year when the LEC value is used as

  4. Arsenic exposure at low-to-moderate levels and skin lesions, arsenic metabolism, neurological functions, and biomarkers for respiratory and cardiovascular diseases: Review of recent findings from the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh

    International Nuclear Information System (INIS)

    Chen Yu; Parvez, Faruque; Gamble, Mary; Islam, Tariqul; Ahmed, Alauddin; Argos, Maria; Graziano, Joseph H.; Ahsan, Habibul

    2009-01-01

    The contamination of groundwater by arsenic in Bangladesh is a major public health concern affecting 35-75 million people. Although it is evident that high levels (> 300 μg/L) of arsenic exposure from drinking water are related to adverse health outcomes, health effects of arsenic exposure at low-to-moderate levels (10-300 μg/L) are not well understood. We established the Health Effects of Arsenic Longitudinal Study (HEALS) with more than 20,000 men and women in Araihazar, Bangladesh, to prospectively investigate the health effects of arsenic predominately at low-to-moderate levels (0.1 to 864 μg/L, mean 99 μg/L) of arsenic exposure. Findings to date suggest adverse effects of low-to-moderate levels of arsenic exposure on the risk of pre-malignant skin lesions, high blood pressure, neurological dysfunctions, and all-cause and chronic disease mortality. In addition, the data also indicate that the risk of skin lesion due to arsenic exposure is modifiable by nutritional factors, such as folate and selenium status, lifestyle factors, including cigarette smoking and body mass index, and genetic polymorphisms in genes related to arsenic metabolism. The analyses of biomarkers for respiratory and cardiovascular functions support that there may be adverse effects of arsenic on these outcomes and call for confirmation in large studies. A unique strength of the HEALS is the availability of outcome data collected prospectively and data on detailed individual-level arsenic exposure estimated using water, blood and repeated urine samples. Future prospective analyses of clinical endpoints and related host susceptibility will enhance our knowledge on the health effects of low-to-moderate levels of arsenic exposure, elucidate disease mechanisms, and give directions for prevention.

  5. [Studies on markers of exposure and early effect in areas with arsenic pollution: methods and results of the project SEpiAs. Epidemiological studies on population exposed to low-to-moderate arsenic concentration in drinking water].

    Science.gov (United States)

    Bustaffa, Elisa; Bianchi, Fabrizio

    2014-01-01

    Arsenic and its inorganic compounds are classified as human carcinogens. Several epidemiological studies conducted in areas of the world characterized by high arsenic concentration in drinking water, even up to 3,000 μg/l, report associations between arsenic exposure and skin, bladder, lung, liver and kidney cancer as well as cardiovascular diseases, diabetes and reproductive and developmental effects. Since general population is not exposed to these high arsenic concentrations in the last years attention focused on adverse health effects that low-to-moderate arsenic concentrations (0-150 μg/l) in drinking water could induce. The World Health Organization recommends a maximum limit of 10 μg/l for arsenic in drinking water. Almost all epidemiological studies conducted on populations exposed to low-to-moderate arsenic concentrations in drinking water are limited due to problems arising from both individual exposure assessment and low subjects number. The aim of the present review is to collect literature-based evidences regarding adverse health effects associated with exposure to low-to-moderate arsenic concentrations in drinking water (10-150 μg/l) in order to obtain a comprehensive picture of the health outcomes that such exposure can have on general population.

  6. Geothermal system 'Toplets' and geothermal potential of Dojran region

    International Nuclear Information System (INIS)

    Karakashev, Deljo; Delipetrov, Marjan; Jovanov, Kosta

    2008-01-01

    The Toplets geothermal spring that expands into a wide geothermal net in the watershed of Lake Dojran along the geophysical exploration work carried out in the terrain, indicated the presence of a significant geothermal potential in the region. In the future it may become the major factor for the development of vegetable growing, the use of the medicinal properties of the mineral spas and tourism as well as the prosperity of the region. Water temperature in Lake Dojran amounts 15°C to 28°C during the year that is mach higher compared with the temperature of water lakes in neighbouring Greece. This indicates that beneath Lake Dojran there are other geothermal sources that replenish the lake with thermal water. Such manifestations of geothermal energy in the region along with other thermal phenomena speak for the presence of large reserves of geothermal energy in the Dojran depression. (Author)

  7. Geothermal system 'Toplets' and geothermal potential of Dojran region

    International Nuclear Information System (INIS)

    Karakashev, Deljo; Delipetrov, Marjan; Jovanov, Kosta

    2007-01-01

    The Toplets geothermal spring that expands into a wide geothermal net in the watershed of Lake Dojran along the geophysical exploration work carried out in the terrain, indicated the presence of a significant geothermal potential in the region. In the future it may become the major factor for the development of vegetable growing, the use of the medicinal properties of the mineral spas and tourism as well as the prosperity of the region. Water temperature in Lake Dojran amounts 15°C to 28°C during the year that is mach higher compared with the temperature of water lakes in neighbouring Greece. This indicates that beneath Lake Dojran there are other geothermal sources that replenish the lake with thermal water. Such manifestations of geothermal energy in the region along with other thermal phenomena speak for the presence of large reserves of geothermal energy in the Dojran depression. (Author)

  8. Evidence for tectonic, lithologic, and thermal controls on fracture system geometries in an andesitic high-temperature geothermal field

    Science.gov (United States)

    Massiot, Cécile; Nicol, Andrew; McNamara, David D.; Townend, John

    2017-08-01

    Analysis of fracture orientation, spacing, and thickness from acoustic borehole televiewer (BHTV) logs and cores in the andesite-hosted Rotokawa geothermal reservoir (New Zealand) highlights potential controls on the geometry of the fracture system. Cluster analysis of fracture orientations indicates four fracture sets. Probability distributions of fracture spacing and thickness measured on BHTV logs are estimated for each fracture set, using maximum likelihood estimations applied to truncated size distributions to account for sampling bias. Fracture spacing is dominantly lognormal, though two subordinate fracture sets have a power law spacing. This difference in spacing distributions may reflect the influence of the andesitic sequence stratification (lognormal) and tectonic faults (power law). Fracture thicknesses of 9-30 mm observed in BHTV logs, and 1-3 mm in cores, are interpreted to follow a power law. Fractures in thin sections (˜5 μm thick) do not fit this power law distribution, which, together with their orientation, reflect a change of controls on fracture thickness from uniform (such as thermal) controls at thin section scale to anisotropic (tectonic) at core and BHTV scales of observation. However, the ˜5% volumetric percentage of fractures within the rock at all three scales suggests a self-similar behavior in 3-D. Power law thickness distributions potentially associated with power law fluid flow rates, and increased connectivity where fracture sets intersect, may cause the large permeability variations that occur at hundred meter scales in the reservoir. The described fracture geometries can be incorporated into fracture and flow models to explore the roles of fracture connectivity, stress, and mineral precipitation/dissolution on permeability in such andesite-hosted geothermal systems.

  9. High- and middle-energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    High and middle energy geothermal resources correspond to temperature intervals of 220-350 C and 90-180 C, respectively, and are both exploited for electricity production. Exploitation techniques and applications of high and of middle energy geothermics are different. High energy geothermics is encountered in active volcanic and tectonic zones, such as the circum-Pacific fire-belt, the lesser Antilles, the peri-Mediterranean Alpine chain or the African rift zone. The geothermal steam is directly expanded in a turbine protected against gas and minerals corrosion. About 350 high energy plants are distributed in more than 20 different countries and represent 6000 M We. The cost of high energy installed geothermal kWh ranges from 0.20 to 0.50 French Francs. Middle energy geothermics is encountered in sedimentary basins (between 2000 and 4000 m of depth), in localized fractured zones or at lower depth in the high energy geothermal fields. Heat exchangers with organic fluid Rankine cycle technology is used to produce electricity. Unit power of middle energy plants generally ranges from few hundreds of k W to few MW and correspond to a worldwide installed power of about 400 M We. The annual progression of geothermal installed power is estimated to 4 to 8 % in the next years and concerns principally the circum-Pacific countries. In France, geothermal resources are mainly localized in overseas departments. (J.S.). 3 photos

  10. Geothermal rice drying unit in Kotchany, Macedonia

    International Nuclear Information System (INIS)

    Popovski, K.; Dimitrov, K.; Andrejevski, B.; Popovska, S.

    1992-01-01

    A geothermal field in Kotchany (Macedonia) has very advantageous characteristics for direct application purposes. Low content of minerals, moderate temperature (78C) and substantial available geothermal water flow (up to 300 1/s) enabled the establishment of a district heating scheme comprising mainly agricultural and industrial uses. A rice drying unit of 10 t/h capacity was installed 8 years ago, using the geothermal water as the primary heat source. A temperature drop of 75/50C enables the adaptation of conventional drying technology, already proven in practice in the surrounding rice growing region. Water to air heat exchanger and all necessary equipment and materials are of local production, made of copper and carbon steel. The use of such drying units is strongly recommended for the concrete district heating scheme because it offers a very simple geothermal application and enables improvement in the annual heating load factor without high investments in geothermal water distribution lines

  11. Present situation and future of utilization of geothermal energy in China

    International Nuclear Information System (INIS)

    Huang, Z.; Zhi, W.F.

    1998-01-01

    From the 1970s, the Chinese government increased investment in the development of geothermal resources and other new energy, and some experimental geothermal power stations have been built successfully. In the late 1980s, the exploration of high temperature geothermal resources was increased. Geothermal fluid with temperatures over 200 C was measured in several boreholes. In ZK4002 well, Yangbajing, the temperature is even as high as 329.8 C. By the year 2010, several geothermal power plants with high temperatures and great capacity will be built, so that great advances will be made in the development of geothermal energy in China

  12. Summary of the 2010 assessment on medium- to low-temperature geothermal resources in Mexico; Resumen de la evaluacion 2010 de los recursos geotermicos mexicanos de temperatura intermedia a baja

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Eduardo R.; Torres, Rodolfo J.; Martinez Estrella, J. Ignacio; Reyes Picasso, Neftali [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: iglesias@iie.org.mx

    2011-07-15

    In 2003 we published our first assessment of the medium- to low-temperature (T {<=} 200 degrees Celsius) Mexican geothermal resources. The assessment was based on a database of 1,358 geothermal manifestations (surface manifestations, e.g. springs, fumaroles, water wells, etc.) identified at that time. Due to a lack of information on one or more relevant parameters, such as geographical coordinates, reservoir or surface temperatures, types of fluid, etc., that assessment included only about 30% of the geothermal manifestations in the database. Since then our group has increased significantly the amount of information in the database, using field work and data compilation from different sources. We have developed a database linked with a Geographical Information System (GIS). This work presents an updated assessment of the medium- to low-temperature Mexican geothermal resources based on our current database, which includes 2,361 geothermal manifestations. As before, we have relied on the volume method and Montecarlo simulations to estimate geothermal resources and their uncertainties for each identified geothermal system. These geothermal systems very often include more than one geothermal manifestation, generally increasing the reliability of the individual estimations. In all, we estimated the geothermal resources of 918 individual geothermal systems which included 1,797 geothermal manifestations (as before, a significant fraction of the identified manifestations lack relevant information) located in 26 of the 32 Mexican States. In most cases these resources would be classified as inferred resources, according to the Australian Geothermal Code. We then added the inferred thermal-energy statistical distributions of the 918 geothermal systems by Montecarlo simulation, obtaining the total estimated geothermal resources of the 26 Mexican States and its uncertainty. With the resulting statistical distribution, we estimated the total-thermal energy stored in the 918

  13. Geothermal in transition

    International Nuclear Information System (INIS)

    Anderson, J.L.

    1991-01-01

    This article examines the current market for geothermal projects in the US and overseas. The topics of the article include future capacity needs, upgrading the Coso Geothermal project, the productivity of the Geysers area of Northern California, the future of geothermal, and new projects at Soda Lake, Carson Basin, Unalaska Island, and the Puna Geothermal Venture in Hilo, Hawaii

  14. Future directions and cycles for electricity production from geothermal resources

    International Nuclear Information System (INIS)

    Michaelides, Efstathios E.

    2016-01-01

    Graphical abstract: 25% more power may be produced using binary-flashing geothermal cycles. - Highlights: • Power from geothermal power plants is continuously available and “dispatchable.” • The next generation of geothermal will include more binary plants. • Lower temperature geothermal resources will be utilized in the future. • Dry rock resources may produce a high fraction of electricity in several countries. - Abstract: Geothermal power production is economically competitive and capable to produce a high percentage of the electric power demand in several countries. The currently operating geothermal power plants utilize water from an aquifer at relatively higher temperatures and produce power using dry steam, flashing or binary cycles. A glance at the map of the global geothermal resources proves that there is a multitude of sites, where the aquifer temperature is lower. There are also many geothermal resources where a high geothermal gradient exists in the absence of an aquifer. It becomes apparent that the next generation of geothermal power plants will utilize more of the lower-temperature aquifer resources or the dry resources. For such power plants to be economically competitive, modified or new cycles with higher efficiencies must be used. This paper presents two methods to increase the efficiency of the currently used geothermal cycles. The first uses a binary-flashing system to reduce the overall entropy production, thus, producing more electric power from the resource. The second describes a heat extraction system to be used with dry hot-rock resources.

  15. A new look at the statistical assessment of approximate and rigorous methods for the estimation of stabilized formation temperatures in geothermal and petroleum wells

    International Nuclear Information System (INIS)

    Espinoza-Ojeda, O M; Santoyo, E; Andaverde, J

    2011-01-01

    Approximate and rigorous solutions of seven heat transfer models were statistically examined, for the first time, to estimate stabilized formation temperatures (SFT) of geothermal and petroleum boreholes. Constant linear and cylindrical heat source models were used to describe the heat flow (either conductive or conductive/convective) involved during a borehole drilling. A comprehensive statistical assessment of the major error sources associated with the use of these models was carried out. The mathematical methods (based on approximate and rigorous solutions of heat transfer models) were thoroughly examined by using four statistical analyses: (i) the use of linear and quadratic regression models to infer the SFT; (ii) the application of statistical tests of linearity to evaluate the actual relationship between bottom-hole temperatures and time function data for each selected method; (iii) the comparative analysis of SFT estimates between the approximate and rigorous predictions of each analytical method using a β ratio parameter to evaluate the similarity of both solutions, and (iv) the evaluation of accuracy in each method using statistical tests of significance, and deviation percentages between 'true' formation temperatures and SFT estimates (predicted from approximate and rigorous solutions). The present study also enabled us to determine the sensitivity parameters that should be considered for a reliable calculation of SFT, as well as to define the main physical and mathematical constraints where the approximate and rigorous methods could provide consistent SFT estimates

  16. Hot Dry Rock; Geothermal Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-01-01

    The commercial utilization of geothermal energy forms the basis of the largest renewable energy industry in the world. More than 5000 Mw of electrical power are currently in production from approximately 210 plants and 10 000 Mw thermal are used in direct use processes. The majority of these systems are located in the well defined geothermal generally associated with crustal plate boundaries or hot spots. The essential requirements of high subsurface temperature with huge volumes of exploitable fluids, coupled to environmental and market factors, limit the choice of suitable sites significantly. The Hot Dry Rock (HDR) concept at any depth originally offered a dream of unlimited expansion for the geothermal industry by relaxing the location constraints by drilling deep enough to reach adequate temperatures. Now, after 20 years intensive work by international teams and expenditures of more than $250 million, it is vital to review the position of HDR in relation to the established geothermal industry. The HDR resource is merely a body of rock at elevated temperatures with insufficient fluids in place to enable the heat to be extracted without the need for injection wells. All of the major field experiments in HDR have shown that the natural fracture systems form the heat transfer surfaces and that it is these fractures that must be for geothermal systems producing from naturally fractured formations provide a basis for directing the forthcoming but, equally, they require accepting significant location constraints on HDR for the time being. This paper presents a model HDR system designed for commercial operations in the UK and uses production data from hydrothermal systems in Japan and the USA to demonstrate the reservoir performance requirements for viable operations. It is shown that these characteristics are not likely to be achieved in host rocks without stimulation processes. However, the long term goal of artificial geothermal systems developed by systematic

  17. Geothermal resource assessment in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngmin; Kim, Hyoung Chan [Korea Institute of Geoscience and Mineral Resources (Korea); Park, Sungho; Kim, Jongchan; Koo, Min-Ho [Kongju National University (Korea)

    2010-10-15

    To estimate available geothermal energy and to construct temperature at depth maps in Korea, various geothermal data have been used. Those include 1560 thermal property data such as thermal conductivity, specific heat and density, 353 heat flow data, 54 surface temperature data, and 180 heat production data. In Korea, subsurface temperature ranges from 23.9 C to 47.9 C at a depth of 1 km, from 34.2 C to 79.7 C at 2 km, from 44.2 C to 110.9 C at 3 km, from 53.8 C to 141.5 C at 4 km, and from 63.1 C to 171.6 C at 5 km. The total available subsurface geothermal energy in Korea is 4.25 x 10{sup 21} J from surface to a depth of 1 km, 1.67 x 10{sup 22} J to 2 km, 3.72 x 10{sup 22} J to 3 km, 6.52 x 10{sup 22} J to 4 km, and 1.01 x 10{sup 23} J to 5 km. In particular, the southeastern part of Korea shows high temperatures at depths and so does high geothermal energy. If only 2% of geothermal resource from surface to a depth of 5 km is developed in Korea, energy from geothermal resources would be equivalent to about 200 times annual consumption of primary energy ({proportional_to}2.33 x 10{sup 8} TOE) in Korea in 2006. (author)

  18. Hydrogen Peroxide Cycling in High-Temperature Acidic Geothermal Springs and Potential Implications for Oxidative Stress Response

    Directory of Open Access Journals (Sweden)

    Margaux M. Meslé

    2017-05-01

    Full Text Available Hydrogen peroxide (H2O2, superoxide (O2•-, and hydroxyl radicals (OH• are produced in natural waters via ultraviolet (UV light-induced reactions between dissolved oxygen (O2 and organic carbon, and further reaction of H2O2 and Fe(II (i.e., Fenton chemistry. The temporal and spatial dynamics of H2O2 and other dissolved compounds [Fe(II, Fe(III, H2S, O2] were measured during a diel cycle (dark/light in surface waters of three acidic geothermal springs (Beowulf Spring, One Hundred Springs Plain, and Echinus Geyser Spring; pH = 3–3.5, T = 68–80°C in Norris Geyser Basin, Yellowstone National Park. In situ analyses showed that H2O2 concentrations were lowest (ca. 1 μM in geothermal source waters containing high dissolved sulfide (and where oxygen was below detection and increased by 2-fold (ca. 2–3 μM in oxygenated waters corresponding to Fe(III-oxide mat formation down the water channel. Small increases in dissolved oxygen and H2O2 were observed during peak photon flux, but not consistently across all springs sampled. Iron-oxide microbial mats were sampled for molecular analysis of ROS gene expression in two primary autotrophs of acidic Fe(III-oxide mat ecosystems: Metallosphaera yellowstonensis (Archaea and Hydrogenobaculum sp. (Bacteria. Expression (RT-qPCR assays of specific stress-response genes (e.g., superoxide dismutase, peroxidases of the primary autotrophs were used to evaluate possible changes in transcription across temporal, spatial, and/or seasonal samples. Data presented here documented the presence of H2O2 and general correlation with dissolved oxygen. Moreover, two dominant microbial populations expressed ROS response genes throughout the day, but showed less expression of key genes during peak sunlight. Oxidative stress response genes (especially external peroxidases were highly-expressed in microorganisms within Fe(III-oxide mat communities, suggesting a significant role for these proteins during survival and growth in

  19. Geothermal Modesty

    International Nuclear Information System (INIS)

    Anon.

    2004-01-01

    This publication of the Areva Group, a world nuclear industry leader, provides information on the energy in many domains. This issue deals with the uses for radioactivity, the future of the green electricity, the energy policy of Rhone-alps region, the end of the nuclear in Belgium, the nuclear propulsion to explore the solar system, the involvement of the Unites States in the hydrogen development, the gas exportation of China. A special part is devoted to the possibility of the geothermal energy. (A.L.B.)

  20. NEDO Forum 2000. Geothermal technology development session (new development of geothermal energy); Chinetsu gijutsu kaihatsu session. Chinetsu energy no shintenkai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-09-01

    The following themes were presented at this session: (1) geothermal development in the future, (2) the current status of geothermal development and utilization, (3) surveys on the promotion of geothermal development, and (4) verification and investigation on geothermal exploration technologies, development of hot water utilizing power generation plants, and international cooperation on geothermal development and utilization. In Item 2, report was made on the current status of geothermal power plants in Japan and their future development targets, long-term overview of geothermal development, measures and budgets to achieve the targets of geothermal development. In Item 3, it is reported that out of 48 areas completed of the survey (including the new promotion surveyed areas), the areas possible of steam power generation and confirmed of temperatures higher than 200 degrees C are 30 areas, and the areas possible of binary power generation (using down hole pumps) and small to medium scale power generation, confirmed of temperatures of 100 to 200 degrees C are 13 areas. In Item 4, reports were made on the reservoir bed variation exploring method, surveys on deep geothermal resources, a 10-MW demonstration plant, a system to detect well bottom information during excavation of geothermal wells, a technology to collect deep geothermal resources, and a hot-rock using power generation system. In Item 5, geothermal exploration in remote islands in the eastern part of Indonesia, and the IEA cooperation projects were reported. (NEDO)

  1. Heat transfer measurements on an incidence-tolerant low pressure turbine blade in a high speed linear cascade at low to moderate Reynolds numbers

    Science.gov (United States)

    Moualeu, Leolein Patrick Gouemeni

    Runway-independent aircraft are expected to be the future for short-haul flights by improving air transportation and reducing area congestion encountered in airports. The Vehicle Systems Program of NASA identified a Large Civil Tilt-Rotor, equipped with variable-speed power-turbine engines, as the best concept. At cruise altitude, the engine rotor-speed will be reduced by as much as the 50% of take-off speed. The large incidence variation in the low pressure turbine associated with the change in speed can be detrimental to the engine performance. Low pressure turbine blades in cruise altitude are more predisposed to develop regions of boundary layer separation. Typical phenomenon such as impinging wakes on downstream blades and mainstream turbulences enhance the complexity of the flow in low pressure turbines. It is therefore important to be able to understand the flow behavior to accurately predict the losses. Research facilities are seldom able to experimentally reproduce low Reynolds numbers at relevant engine Mach number. Having large incidence swing as an additional parameter in the investigation of the boundary layer development, on a low pressure turbine blade, makes this topic unique and as a consequence requires a unique facility to conduct the experimental research. The compressible flow wind tunnel facility at the University of North Dakota had been updated to perform steady state experiments on a modular-cascade, designed to replicate a large variation of the incidence angles. The high speed and low Reynolds number facility maintained a sealed and closed loop configuration for each incidence angle. The updated facility is capable to produce experimental Reynolds numbers as low as 45,000 and as high as 570,000 at an exit Mach number of 0.72. Pressure and surface temperature measurements were performed at these low pressure turbine conditions. The present thesis investigates the boundary layer development on the surface of an Incidence-tolerant blade. The

  2. DMRC studies geothermal energy options

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-03-01

    The Deep Mining Research Consortium (DMRC) is an industry-led research consortium that includes Vale Inco, Xstrata, Rio Tinto, Goldcorp, Agnico-Eagle, Barrick Gold, CANMET and the City of Sudbury. This article reported on the application of geothermal energy technologies to cool deep mine workings and use the heat from underground to produce energy to heat surface buildings. Researchers at the University of British Columbia's Centre for Environmental Research in Minerals, Metals and Materials have proposed the use of heat pumps and water-to-air heat exchangers at depth to chill mine workings. The heat pumps would act as refrigerators, taking heat from one area and moving it elsewhere. The purpose would be to extract heat from naturally occurring ground water and pass the chilled water through a heat exchanger to cool the air. The heated water would then be pumped to surface and used to heat surface facilities. The technology is well suited for using geothermal energy from decommissioned mines for district heating. The technology has been successfully used in Spring Hill, Nova Scotia, where geothermal energy from a decommissioned coal mine is used to heat an industrial park. A feasibility study is also underway for the city of Yellowknife in the Northwest Territories to produce up to 10 megawatts of heat from the Con Gold Mine, enough energy to heat half of Yellowknife. Geothermal energy can also be used to generate electricity, particularly in the Pacific Rim where underground temperatures are higher and closer to surface. In Sudbury Ontario, the enhanced geothermal systems technology would require two holes drilled to a depth of four kilometers. The ground between the two holes should be fractured to create an underground geothermal circuit. Geothermal energy does not produce any greenhouse gases or chemical wastes. 1 fig.

  3. Application of low enthalpy geothermal energy

    International Nuclear Information System (INIS)

    Stancher, B.; Giannone, G.

    2007-01-01

    Geothermal energy comes from the superficial layers of the Earth's crust; it can be exploited in several ways, depending on its temperature. Many systems have been developed to use this clean and renewable energy resource. This paper deals with a particular application of low enthalpy geothermal energy in Latisana (district of Udine NE, Italy). The Latisana's indoor stadium is equipped with geothermal plant that uses low temperature water (29-30 0 ) to provide heating. Economic analysis shows that the cost of its plant is comparable to the cost powered by other kinds of renewable energy resources

  4. Geothermal Reservoir Well Stimulation Program: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    A literature search on reservoir and/or well stimulation techniques suitable for application in geothermal fields is presented. The literature on stimulation techniques in oil and gas field applications was also searched and evaluated as to its relevancy to geothermal operations. The equivalent low-temperature work documented in the open literature is cited, and an attempt is made to evaluate the relevance of this information as far as high-temperature stimulation work is concerned. Clays play an important role in any stimulation work. Therefore, special emphasis has been placed on clay behavior anticipated in geothermal operations. (MHR)

  5. A pilot study examining the effects of low-volume high-intensity interval training and continuous low to moderate intensity training on quality of life, functional capacity and cardiovascular risk factors in cancer survivors.

    Science.gov (United States)

    Toohey, Kellie; Pumpa, Kate L; Arnolda, Leonard; Cooke, Julie; Yip, Desmond; Craft, Paul S; Semple, Stuart

    2016-01-01

    The aim of this study was to evaluate the effects of low-volume high-intensity interval training and continuous low to moderate intensity training on quality of life, functional capacity and cardiovascular disease risk factors in cancer survivors. Cancer survivors within 24 months post-diagnosis were randomly assigned into the low-volume high-intensity interval training group ( n  = 8) or the continuous low to moderate intensity training group ( n  = 8) group for 36 sessions (12 weeks) of supervised exercise. The low-volume high-intensity interval training (LVHIIT) group performed 7 × 30 s intervals (≥85% maximal heart rate) and the continuous low to moderate intensity training (CLMIT) group performed continuous aerobic training for 20 min (≤55% maximal heart rate) on a stationary bike or treadmill. Significant improvements (time) were observed for 13 of the 23 dependent variables (ES 0.05-0.61, p  ≤ 0.05). An interaction effect was observed for six minute walk test (18.53% [32.43-4.63] ES 0.50, p  ≤ 0.01) with the LVHIIT group demonstrating greater improvements. These preliminary findings suggest that both interventions can induce improvements in quality of life, functional capacity and selected cardiovascular disease risk factors. The LVHIIT program was well tolerated by the participants and our results suggest that LVHIIT is the preferred modality to improve fitness (6MWT); it remains to be seen which intervention elicits the most clinically relevant outcomes for patients. A larger sample size with a control group is required to confirm the significance of these findings.

  6. Microbiological monitoring in geothermal plants

    Science.gov (United States)

    Alawi, M.; Lerm, S.; Vetter, A.; Vieth, A.; Seibt, A.; Wolfgramm, M.; Würdemann, H.

    2009-12-01

    In times of increasing relevance of alternative energy resources the utilization of geothermal energy and subsurface energy storage gains importance and arouses increasing interest of scientists. The research project “AquiScreen” investigates the operational reliability of geothermally used groundwater systems under microbial, geochemical, mineralogical and petrological aspects. Microbiological analyses based on fluid and solid phases of geothermal systems are conducted to evaluate the impact of microbial populations on these systems. The presentation focuses on first results obtained from microbiological monitoring of geothermal plants located in two different regions of Germany: the North German Basin and the Molasse Basin in the southern part characterized by different salinities and temperatures. Fluid and filter samples taken during regular plant operation were investigated using genetic fingerprinting based on PCR-amplified 16S rRNA genes to characterize the microbial biocenosis of the geothermal aquifer. Sequencing of dominant bands of the fingerprints and the subsequent comparison to 16S rRNA genes from public databases enables a correlation to metabolic classes and provides information about the biochemical processes in the deep biosphere. The genetic profiles revealed significant differences in microbiological community structures of geothermal aquifers investigated. Phylogenetic analyses indicate broad metabolical diversity adapted to the specific conditions in the aquifers. Additionally a high amount of so far uncultivated microorganisms was detected indicating very specific indigenous biocenosis. However, in all geothermal plants bacteria were detected despite of fluid temperatures from 45° to 120°C. The identified microorganisms are closely related to thermophilic and hyperthermophilic species detectable in hot wells and hot springs, like Thermus scotoductus and Thermodesulfovibrio yellowstonii, respectively. Halophilic species were detected in

  7. RPM-WEBBSYS: A web-based computer system to apply the rational polynomial method for estimating static formation temperatures of petroleum and geothermal wells

    Science.gov (United States)

    Wong-Loya, J. A.; Santoyo, E.; Andaverde, J. A.; Quiroz-Ruiz, A.

    2015-12-01

    A Web-Based Computer System (RPM-WEBBSYS) has been developed for the application of the Rational Polynomial Method (RPM) to estimate static formation temperatures (SFT) of geothermal and petroleum wells. The system is also capable to reproduce the full thermal recovery processes occurred during the well completion. RPM-WEBBSYS has been programmed using advances of the information technology to perform more efficiently computations of SFT. RPM-WEBBSYS may be friendly and rapidly executed by using any computing device (e.g., personal computers and portable computing devices such as tablets or smartphones) with Internet access and a web browser. The computer system was validated using bottomhole temperature (BHT) measurements logged in a synthetic heat transfer experiment, where a good matching between predicted and true SFT was achieved. RPM-WEBBSYS was finally applied to BHT logs collected from well drilling and shut-in operations, where the typical problems of the under- and over-estimation of the SFT (exhibited by most of the existing analytical methods) were effectively corrected.

  8. Geothermal Technologies Program Geoscience and Supporting Technologies 2001 University Research Summaries

    International Nuclear Information System (INIS)

    Creed, R.J.; Laney, P.T.

    2002-01-01

    The U.S. Department of Energy Office of Wind and Geothermal Technologies (DOE) is funding advanced geothermal research through University Geothermal Research solicitations. These solicitations are intended to generate research proposals in the areas of fracture permeability location and characterization, reservoir management and geochemistry. The work funded through these solicitations should stimulate the development of new geothermal electrical generating capacity through increasing scientific knowledge of high-temperature geothermal systems. In order to meet this objective researchers are encouraged to collaborate with the geothermal industry. These objectives and strategies are consistent with DOE Geothermal Energy Program strategic objectives

  9. Geothermal Technologies Program Geoscience and Supporting Technologies 2001 University Research Summaries

    Energy Technology Data Exchange (ETDEWEB)

    Creed, R.J.; Laney, P.T.

    2002-05-14

    The U.S. Department of Energy Office of Wind and Geothermal Technologies (DOE) is funding advanced geothermal research through University Geothermal Research solicitations. These solicitations are intended to generate research proposals in the areas of fracture permeability location and characterization, reservoir management and geochemistry. The work funded through these solicitations should stimulate the development of new geothermal electrical generating capacity through increasing scientific knowledge of high-temperature geothermal systems. In order to meet this objective researchers are encouraged to collaborate with the geothermal industry. These objectives and strategies are consistent with DOE Geothermal Energy Program strategic objectives.

  10. Geothermal Technologies Program Geoscience and Supporting Technologies 2001 University Research Summaries

    Energy Technology Data Exchange (ETDEWEB)

    Creed, Robert John; Laney, Patrick Thomas

    2002-06-01

    The U.S. Department of Energy Office of Wind and Geothermal Technologies (DOE) is funding advanced geothermal research through University Geothermal Research solicitations. These solicitations are intended to generate research proposals in the areas of fracture permeability location and characterization, reservoir management and geochemistry. The work funded through these solicitations should stimulate the development of new geothermal electrical generating capacity through increasing scientific knowledge of high-temperature geothermal systems. In order to meet this objective researchers are encouraged to collaborate with the geothermal industry. These objectives and strategies are consistent with DOE Geothermal Energy Program strategic objectives.

  11. Characteristics of geothermal structures of Poprad basin in terms of numerical modeling

    International Nuclear Information System (INIS)

    Bagelova, A.; Fendek, M.

    2011-01-01

    Poprad basin is one of the promising areas in terms of geothermal resources. In terms of impact on the environment and the exploitation of geothermal waters it is important to quantify the natural geothermal water quantity. One of the most progressive methods of their evaluation is a method of numerical modelling. Before model creation it is necessary to characterize the geothermal structure. Character of hydro-geothermal structure consists of an analysis of Spatial distribution of collectors, hydraulic properties of collectors of geothermal water, pressure and temperature conditions and boundary conditions. Basic characteristics of geothermal energy transfer in the Poprad basin are described. (authors)

  12. New Mexico Geothermal Data Base

    International Nuclear Information System (INIS)

    Witcher, J.C.; Whittier, J.; Morgan, R.

    1990-01-01

    This paper reports on the New Mexico Geothermal Data Base (NMGDB) which is a comprehensive public-domain data base of low-temperature geothermal resource information for New Mexico that is designed to assist researchers and developers. A broad range of geoscience, engineering, climatic, economic, and land status information are complied in the dBASE III PLUS data base management system for use on an IBM or IBM-compatible personal computer. A user friendly menu format with on-screen prompts allows easy and convenient use

  13. Exergetic and economic comparison of ORC and Kalina cycle for low temperature enhanced geothermal system in Brazil

    International Nuclear Information System (INIS)

    Campos Rodríguez, Carlos Eymel; Escobar Palacio, José Carlos; Venturini, Osvaldo J.; Silva Lora, Electo E.; Cobas, Vladimir Melián; Marques dos Santos, Daniel; Lofrano Dotto, Fábio R.; Gialluca, Vernei

    2013-01-01

    This paper deals with the thermodynamic analysis, of both the first and second law of thermodynamic of two different technologies, (ORC and Kalina cycle) for power production through an enhanced geothermal system (EGS). In order to find a better performance of both thermal cycles it were evaluated 15 different working fluids for ORC and three different composition of the ammonia–water mixture for the Kalina cycle. In this work, the Aspen-HYSYS software was used to simulate both thermal cycles and to calculate the thermodynamic properties based on Peng–Robinson Stryjek–Vera (PRSV) Equation of State (EoS). At the end the two cycles was compared using an economic analysis with the fluid that offers the best performance for each thermal cycle which are R-290 for ORC and for Kalina cycle a composition of the mixture of 84% of ammonia mass fraction and 16% of water mass fraction. For this conditions the Kalina cycle produce 18% more net power than the ORC. A levelized electricity costs of 0.22 €/kW h was reached for ORC and 0.18 €/kW h for Kalina cycle. Finally a sensitivity analysis of the EGS LCOE was carried out for a few economic parameters to determinate how is the variation of LCOE for a % change from the base case. -- Highlights: ► The aim of this paper is to compare both cycles (ORC and Kalina). ► Kalina cycle offer 18% more net power than ORC and require 37% less mass flow rate. ► It was obtained 17.8% lower levelized electricity costs for Kalina cycle over the ORC

  14. Exergetic and economic comparison of ORC and Kalina cycle for low temperature enhanced geothermal system in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Campos Rodríguez, Carlos Eymel, E-mail: eymelcampos@hotmail.com [Federal University of Itajuba (UNIFEI), Mechanical Engineering Institute – IEM, Excellence Group in Thermal Power and Distributed Generation (NEST), Minas Gerais (Brazil); Escobar Palacio, José Carlos; Venturini, Osvaldo J.; Silva Lora, Electo E.; Cobas, Vladimir Melián [Federal University of Itajuba (UNIFEI), Mechanical Engineering Institute – IEM, Excellence Group in Thermal Power and Distributed Generation (NEST), Minas Gerais (Brazil); Marques dos Santos, Daniel, E-mail: danielmarques.Santos@aes.com [AES Tietê, Bauru, São Paulo (Brazil); Lofrano Dotto, Fábio R., E-mail: fabio@farolconsultoria.com.br [FAROL Pesquisa, Desenvolvimento e Consultoria (Brazil); Gialluca, Vernei [Gênera Serviços e Comércio LTDA (Brazil)

    2013-04-05

    This paper deals with the thermodynamic analysis, of both the first and second law of thermodynamic of two different technologies, (ORC and Kalina cycle) for power production through an enhanced geothermal system (EGS). In order to find a better performance of both thermal cycles it were evaluated 15 different working fluids for ORC and three different composition of the ammonia–water mixture for the Kalina cycle. In this work, the Aspen-HYSYS software was used to simulate both thermal cycles and to calculate the thermodynamic properties based on Peng–Robinson Stryjek–Vera (PRSV) Equation of State (EoS). At the end the two cycles was compared using an economic analysis with the fluid that offers the best performance for each thermal cycle which are R-290 for ORC and for Kalina cycle a composition of the mixture of 84% of ammonia mass fraction and 16% of water mass fraction. For this conditions the Kalina cycle produce 18% more net power than the ORC. A levelized electricity costs of 0.22 €/kW h was reached for ORC and 0.18 €/kW h for Kalina cycle. Finally a sensitivity analysis of the EGS LCOE was carried out for a few economic parameters to determinate how is the variation of LCOE for a % change from the base case. -- Highlights: ► The aim of this paper is to compare both cycles (ORC and Kalina). ► Kalina cycle offer 18% more net power than ORC and require 37% less mass flow rate. ► It was obtained 17.8% lower levelized electricity costs for Kalina cycle over the ORC.

  15. EQUILGAS: Program to estimate temperatures and in situ two-phase conditions in geothermal reservoirs using three combined FT-HSH gas equilibria models

    Science.gov (United States)

    Barragán, Rosa María; Núñez, José; Arellano, Víctor Manuel; Nieva, David

    2016-03-01

    Exploration and exploitation of geothermal resources require the estimation of important physical characteristics of reservoirs including temperatures, pressures and in situ two-phase conditions, in order to evaluate possible uses and/or investigate changes due to exploitation. As at relatively high temperatures (>150 °C) reservoir fluids usually attain chemical equilibrium in contact with hot rocks, different models based on the chemistry of fluids have been developed that allow deep conditions to be estimated. Currently either in water-dominated or steam-dominated reservoirs the chemistry of steam has been useful for working out reservoir conditions. In this context, three methods based on the Fischer-Tropsch (FT) and combined H2S-H2 (HSH) mineral-gas reactions have been developed for estimating temperatures and the quality of the in situ two-phase mixture prevailing in the reservoir. For these methods the mineral buffers considered to be controlling H2S-H2 composition of fluids are as follows. The pyrite-magnetite buffer (FT-HSH1); the pyrite-hematite buffer (FT-HSH2) and the pyrite-pyrrhotite buffer (FT-HSH3). Currently from such models the estimations of both, temperature and steam fraction in the two-phase fluid are obtained graphically by using a blank diagram with a background theoretical solution as reference. Thus large errors are involved since the isotherms are highly nonlinear functions while reservoir steam fractions are taken from a logarithmic scale. In order to facilitate the use of the three FT-HSH methods and minimize visual interpolation errors, the EQUILGAS program that numerically solves the equations of the FT-HSH methods was developed. In this work the FT-HSH methods and the EQUILGAS program are described. Illustrative examples for Mexican fields are also given in order to help the users in deciding which method could be more suitable for every specific data set.

  16. Insight into the Geothermal Structure in Chingshui, Ilan, Taiwan

    Directory of Open Access Journals (Sweden)

    Lun-Tao Tong

    2008-01-01

    Full Text Available The Chingshui geothermal field is the largest known productive geothermal area in Taiwan. The purpose of this paper is to delineate this geothermal structure by integrating geophysical data and borehole information. The existence of a magma chamber in the shallow crust and shallow intrusive igneous rock results in a high heat flow and geothermal gradient; furthermore, the NE deep fault system within the meta-sandstones provides meteoric recharge from a higher elevation to artesianally drive the geothermal system. There is evidence that geothermal fluid deeply circulated within the fracture zone and was heated by a deeply located body of hot rock. The geothermal reservoir of the Chingshui geothermal field might be related to the fracture zone of the Chingshuihsi fault. It is bounded by the C-fault in the north and Xiaonanao fault in the south. Based on information obtained from geophysical interpretations and well logs, a 3-D geothermal conceptual model is constructed in this study. Further, the geothermal reservoir is confined to an area that is 260 m in width, N21°W, 1.5 km in length, and has an 80° dip toward the NE. Ahigh-temperature zone is found in the SE region of the reservoir, which is about 500 m in length; this zone is located near the intersection of the Chingshuihsi and Xiaonanao faults. An area on the NE side of the high-temperature zone has been recommended for the drilling of production wells for future geothermal development.

  17. Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy

    Science.gov (United States)

    Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Newell, Andrew J.

    2015-04-01

    The first UK city-wide heat map is described based on measurements of groundwater from a shallow superficial aquifer in the coastal city of Cardiff, Wales, UK. The UK Government has a target of reducing greenhouse gas emissions by 80% by 2050 (Climate Change Act 2008) and low carbon technologies are key to achieving this. To support the use of ground source heating we characterised the shallow heat potential of an urban aquifer to produce a baseline dataset which is intended to be used as a tool to inform developers and to underpin planning and regulation. We exploited an existing network of 168 groundwater monitoring boreholes across the city, recording the water temperature in each borehole at 1m depth intervals up to a depth of 20m. We recorded groundwater temperatures during the coldest part of 2014, and repeat profiling of the boreholes in different seasons has added a fourth dimension to our results and allowed us to characterise the maximum depth of seasonal temperature fluctuation. The temperature profiles were used to create a 3D model of heat potential within the aquifer using GOCAD® and the average borehole temperatures were contoured using Surfer® 10 to generate a 2D thermal resource map to support future assessment of urban Ground Source Heat Pumps prospectively. The average groundwater temperature in Cardiff was found to be above the average for England and Wales (11.3°C) with 90% of boreholes in excess of this figure by up to 4°C. The subsurface temperature profiles were also found to be higher than forecast by the predicted geothermal gradient for the area. Potential sources for heat include: conduction from buildings, basements and sub-surface infrastructure; insulation effects of the urban area and of the geology, and convection from leaking sewers. Other factors include recharge inhibition by drains, localised confinement and rock-water interaction in specific geology. It is likely to be a combination of multiple factors which we are hoping

  18. Model of gypsum, calcite and silica solubilities for application to geothermal waters over a wide range of temperature, P/sub CO/sub 2// and ionic strength. Final technical report, October 1, 1983-September 30, 1984

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    This report describes the construction of a high temperature (25 to 250/sup 0/C), variable P/sub CO/sub 2// (1 to 40 atm), chemical model of mineral (including gypsum, calcite and amorphous silica) solubilities in the system: Na-K-Ca-H-Cl-SO/sub 4/-HCO/sub 3/-CO/sub 3/-CO/sub 2/-SiO/sub 2/-H/sub 2/O. This model was designed to support geothermal energy production needs.

  19. New Geothermal Prospect in North-Eastern Morocco

    OpenAIRE

    Rimi, Abdelkrim; Correia, António; Carneiro, Júlio; Verdoya, Massimo; Zarhloule, Yassine; Lucazeau, Francis; Boughriba, Mimoun; Barkaoui, Alae Eddine

    2010-01-01

    Geothermal data has been indicating promising potentialities in the north-eastern Morocco. This paperpresents new temperature data, recently recorded in water borehole located in the Berkane and Oujda areas. Generally, the observed temperature gradients are rather high. One hole near Berkane, revealed an average geothermal gradient of more than 110 ºC/km at depths greater than 300 m. This result confirms the geothermal gradient estimated in a mining borehole located about 30 km west ...

  20. Nevada low-temperaure geothermal resource assessment: 1994. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Garside, L.J.

    1994-12-31

    Data compilation for the low-temperature program is being done by State Teams in two western states. Final products of the study include: a geothermal database, in hardcopy and as digital data (diskette) listing information on all known low- and moderate- temperature springs and wells in Nevada; a 1:1,000,000-scale map displaying these geothermal localities, and a bibliography of references on Nevada geothermal resources.

  1. Guidebook to Geothermal Finance

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, J. P.; Meurice, J.; Wobus, N.; Stern, F.; Duaime, M.

    2011-03-01

    This guidebook is intended to facilitate further investment in conventional geothermal projects in the United States. It includes a brief primer on geothermal technology and the most relevant policies related to geothermal project development. The trends in geothermal project finance are the focus of this tool, relying heavily on interviews with leaders in the field of geothermal project finance. Using the information provided, developers and investors may innovate in new ways, developing partnerships that match investors' risk tolerance with the capital requirements of geothermal projects in this dynamic and evolving marketplace.

  2. The Use of Geothermal Waters in Podhale in Terms of Tourism and Industrial Applications

    Directory of Open Access Journals (Sweden)

    Piotr Michał Bugajski

    2017-11-01

    Full Text Available In recent years, there has been observed an increased interest of various industrial and economy branches in geothermal waters. In Poland, one of the more famous geothermal systems is the Podhale Basin, which forms an important reservoir of geothermal waters with relatively low mineralization and high temperatures. More and more often geothermal water is used not only for balneological or recreational purposes, but also as a heat source for heating. New areas of application of geothermal waters are also appearing, eg. use of cooled geothermal water as a raw material to produce fresh water. Another example of the application of geothermal waters is the cosmetic industry. For instance, a cream based on geothermal water from Podhale was introduced to the cosmetics market in 2013. This paper presents the possibilities of using the geothermal waters of Podhale, with particular emphasis on geothermal waters from Banska PGP-1, Banska IG-1 and Banska PGP-3 boreholes.

  3. Lithium Isotopes in Geothermal Fluids from Iceland

    Science.gov (United States)

    Millot, R.; Asmundsson, R.; Sanjuan, B.

    2008-12-01

    One of the main objectives of the HITI project (HIgh Temperature Instruments for supercritical geothermal reservoir characterization and exploitation), partially funded by the European Union, is to develop methods to characterize the reservoir and fluids of deep and very high temperature geothermal systems. The chemical composition of geothermal waters in terms of major and trace elements is related to the temperature, the degree of water/rock interaction and the mineralogical assemblage of the bedrock. Traditional geothermometers, such as silica, Na-K, Na-K-Ca or K-Mg applied to geothermal waters, make it possible to estimate the temperature at depth of the reservoir from which the waters are derived. However, the values estimated for deep temperature are not always concordant. The chemical geothermometer Na/Li which presents the singularity of associating two chemical elements, one a major element (sodium) and the other a trace element (Li), can be also used and gives an additional temperature estimation. The primary objective of this work was to better understand the behavior of this last geothermometer using the isotopic systematics of Li in order to apply it at very high temperature Icelandic geothermal systems. One particularly important aspect was to establish the nature, extent and mechanism of Li isotope fractionation between 100 and 350°C during water/rock interaction. For that purpose, we measured Li isotopes of about 25 geothermal waters from Iceland by using a Neptune MC-ICP-MS that enabled the analysis of Li isotopic ratios in geothermal waters with a level of precision of ±0.5‰ (2 standard deviations) on quantities of 10-50 ng of Li. Geothermal waters from Reykjanes, Svartsengi, Nesjavellir, Hveragerdi, Namafjall and Krafla geothermal systems were studied and particular emphasis was placed on the characterization of the behavior of Li isotopes in this volcanic context at high temperature with or without the presence of seawater during water

  4. Structural controls on fluid circulation at the Caviahue-Copahue Volcanic Complex (CCVC) geothermal area (Chile-Argentina), revealed by soil CO2 and temperature, self-potential, and helium isotopes

    Science.gov (United States)

    Roulleau, Emilie; Bravo, Francisco; Pinti, Daniele L.; Barde-Cabusson, Stéphanie; Pizarro, Marcela; Tardani, Daniele; Muñoz, Carlos; Sanchez, Juan; Sano, Yuji; Takahata, Naoto; de la Cal, Federico; Esteban, Carlos; Morata, Diego

    2017-07-01

    Natural geothermal systems are limited areas characterized by anomalously high heat flow caused by recent tectonic or magmatic activity. The heat source at depth is the result of the emplacement of magma bodies, controlled by the regional volcano-tectonic setting. In contrast, at a local scale a well-developed fault-fracture network favors the development of hydrothermal cells, and promotes the vertical advection of fluids and heat. The Southern Volcanic Zone (SVZ), straddling Chile and Argentina, has an important, yet unexplored and undeveloped geothermal potential. Studies on the lithological and tectonic controls of the hydrothermal circulation are therefore important for a correct assessment of the geothermal potential of the region. Here, new and dense self-potential (SP), soil CO2 and temperature (T) measurements, and helium isotope data measured in fumaroles and thermal springs from the geothermal area located in the north-eastern flank of the Copahue volcanic edifice, within the Caviahue Caldera (the Caviahue-Copahue Volcanic Complex - CCVC) are presented. Our results allowed to the constraint of the structural origin of the active thermal areas and the understanding of the evolution of the geothermal system. NE-striking faults in the area, characterized by a combination of SP, CO2, and T maxima and high 3He/4He ratios (up to 8.16 ± 0.21Ra, whereas atmospheric Ra is 1.382 × 10- 6), promote the formation of vertical permeability preferential pathways for fluid circulation. WNW-striking faults represent low-permeability pathways for hydrothermal fluid ascent, but promote infiltration of meteoric water at shallow depths, which dilute the hydrothermal input. The region is scattered with SP, CO2, and T minima, representing self-sealed zones characterized by impermeable altered rocks at depth, which create local barriers for fluid ascent. The NE-striking faults seem to be associated with the upflowing zones of the geothermal system, where the boiling process

  5. Better temperature predictions in geothermal modelling by improved quality of input parameters: a regional case study from the Danish-German border region

    Science.gov (United States)

    Fuchs, Sven; Bording, Thue S.; Balling, Niels

    2015-04-01

    Thermal modelling is used to examine the subsurface temperature field and geothermal conditions at various scales (e.g. sedimentary basins, deep crust) and in the framework of different problem settings (e.g. scientific or industrial use). In such models, knowledge of rock thermal properties is prerequisites for the parameterisation of boundary conditions and layer properties. In contrast to hydrogeological ground-water models, where parameterization of the major rock property (i.e. hydraulic conductivity) is generally conducted considering lateral variations within geological layers, parameterization of thermal models (in particular regarding thermal conductivity but also radiogenic heat production and specific heat capacity) in most cases is conducted using constant parameters for each modelled layer. For such constant thermal parameter values, moreover, initial values are normally obtained from rare core measurements and/or literature values, which raise questions for their representativeness. Some few studies have considered lithological composition or well log information, but still keeping the layer values constant. In the present thermal-modelling scenario analysis, we demonstrate how the use of different parameter input type (from literature, well logs and lithology) and parameter input style (constant or laterally varying layer values) affects the temperature model prediction in sedimentary basins. For this purpose, rock thermal properties are deduced from standard petrophysical well logs and lithological descriptions for several wells in a project area. Statistical values of thermal properties (mean, standard deviation, moments, etc.) are calculated at each borehole location for each geological formation and, moreover, for the entire dataset. Our case study is located at the Danish-German border region (model dimension: 135 x115 km, depth: 20 km). Results clearly show that (i) the use of location-specific well-log derived rock thermal properties and (i

  6. Low enthalpy geothermal for oil sands (LEGO)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Geothermal energy is generated by the slow decay of radioactive materials within the Earth. Geothermal energy resources include the water from hot springs used for heating; the withdrawal of high temperature steam from deep wells; and the use of stable ground or water temperatures near the Earth's surface to heat or cool buildings or in industrial processes. Heat pumps are used to transfer heat or water from the ground into buildings in winter. This paper discussed low enthalpy geothermal options for oil sands processes in order to reduce the use of natural gas and emissions from greenhouse gases (GHGs). The study was also conducted to aid in the development of a portfolio of renewable energy options for the oil and gas sector. The study estimated the costs and benefits of operating a shallow geothermal borehole cluster for meeting a portion of process heat demands for the Nexen's Albian mine. The costs and benefits of operating thermo-chillers integrated with a shallow geothermal borehole cluster for waste heat mitigation were also evaluated. The study showed that geothermal designs can be used to meet a portion of oil sands process heat and cooling demands. Mining operators may reduce carbon emissions and energy costs for process heat demands by installing closed loop borehole heat exchangers. Geothermal heat storage capacity can also be used to increase the efficiency of thermal chillers. It was concluded that pilot plant studies would contribute to a better understanding of the technology. tabs., figs.

  7. Assessment of geothermal resources of the United States, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Muffler, L.J.P. (ed.)

    1979-01-01

    The geothermal resource assessment presented is a refinement and updating of USGS Circular 726. Nonproprietary information available in June 1978 is used to assess geothermal energy in the ground and, when possible, to evaluate the fraction that might be recovered at the surface. Five categories of geothermal energy are discussed: conduction-dominated regimes, igneous-related geothermal systems, high-temperature (> 150/sup 0/C) and intermediate-temperature (90 to 150/sup 0/C) hydrothermal convection systems, low-temperature (< 90/sup 0/C) geothermal waters, and geopressured-geothermal energy (both thermal energy and energy from dissolved methane). Assessment data are presented on three colored maps prepared in cooperation with the National Oceanic and Atmospheric Administration. Separate abstracts were prepared for papers on these five categories.

  8. Federal Geothermal Research Program Update, FY 2000

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Joel Lawrence

    2001-08-01

    The Department of Energy's Geothermal Program serves two broad purposes: 1) to assist industry in overcoming near-term barriers by conducting cost-shared research and field verification that allows geothermal energy to compete in today's aggressive energy markets; and 2) to undertake fundamental research with potentially large economic payoffs. The four categories of work used to distinguish the research activities of the Geothermal Program during FY 2000 reflect the main components of real-world geothermal projects. These categories form the main sections of the project descriptions in this Research Update. Exploration Technology research focuses on developing instruments and techniques to discover hidden hydrothermal systems and to explore the deep portions of known systems. Research in geophysical and geochemical methods is expected to yield increased knowledge of hidden geothermal systems. Reservoir Technology research combines laboratory and analytical investigations with equipment development and field testing to establish practical tools for resource development and management for both hydrothermal reservoirs and enhanced geothermal systems. Research in various reservoir analysis techniques is generating a wide range of information that facilitates development of improved reservoir management tools. Drilling Technology focuses on developing improved, economic drilling and completion technology for geothermal wells. Ongoing research to avert lost circulation episodes in geothermal drilling is yielding positive results. Conversion Technology research focuses on reducing costs and improving binary conversion cycle efficiency, to permit greater use of the more abundant moderate-temperature geothermal resource, and on the development of materials that will improve the operating characteristics of many types of geothermal energy equipment. Increased output and improved performance of binary cycles will result from investigations in heat cycle research.

  9. A numerical analysis of a composition-adjustable Kalina cycle power plant for power generation from low-temperature geothermal sources

    International Nuclear Information System (INIS)

    Wang, Enhua; Yu, Zhibin

    2016-01-01

    Highlights: • A composition-adjustable Kalina cycle is analysed and presented. • An air-cooled condenser is used and thermodynamic performance is analysed. • Composition adjustment can improve system performance significantly. - Abstract: The Kalina cycle is believed to be one of the most promising technologies for power generation from low temperature heat sources such as geothermal energy. So far, most Kalina cycle power plants are designed with a working fluid mixture having a fixed composition, and thus normally operate at a fixed condensing temperature. However, the ambient temperature (i.e., heat sink) varies over a large range as the season changes over a year, particularly in continental climates. Recently, a new concept, i.e., composition-adjustable Kalina cycle, was proposed to develop power plants that can match their condensing temperature with the changing ambient conditions, aiming at improving the cycle’s overall thermal efficiency. However, no detailed analysis of its implementation and the potential benefits under various climate conditions has been reported. For this reason, this paper carried out a comprehensive numerical research on its implementation and performance analysis under several different climate conditions. A mathematical model is firstly established to simulate the working principle of a composition-adjustable Kalina cycle, based on which a numerical program is then developed to analyse the cycle’s performance under various climate conditions. The developed numerical model is verified with some published data. The dynamic composition adjustment in response to the changing ambient temperature is simulated to evaluate its effect on the plant’s performance over a year. The results show that a composition-adjustable Kalina cycle could achieve higher annual-average thermal efficiency than a conventional one with a fixed mixture composition. However, such an improvement of thermal efficiency strongly depends on the heat source

  10. Geothermal Technologies Program: Alaska

    Energy Technology Data Exchange (ETDEWEB)

    2005-02-01

    This fact sheets provides a summary of geothermal potential, issues, and current development in Alaska. This fact sheet was developed as part of DOE's GeoPowering the West initiative, part of the Geothermal Technologies Program.

  11. INEL Geothermal Environmental Program. 1979 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Thurow, T.L.; Sullivan, J.F.

    1980-04-01

    The Raft River Geothermal Environmental Program is designed to assess beneficial and detrimental impacts to the ecosystem resulting from the development of moderate temperature geothermal resources in the valley. The results of this research contribute to developing an understanding of Raft River Valley ecology and provide a basis for making management decisions to reduce potential long-term detrimental impacts on the environment. The environmental monitoring and research efforts conducted during the past six years of geothermal development and planned future research are summarized.

  12. Alaska: a guide to geothermal energy development

    Energy Technology Data Exchange (ETDEWEB)

    Basescu, N.; Bloomquist, R.G.; Higbee, C.; Justus, D.; Simpson, S.

    1980-06-01

    A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

  13. Washington: a guide to geothermal energy development

    Energy Technology Data Exchange (ETDEWEB)

    Bloomquist, R.G.; Basescu, N.; Higbee, C.; Justus, D.; Simpson, S.

    1980-01-01

    A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

  14. South Dakota geothermal handbook

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The sources of geothermal fluids in South Dakota are described and some of the problems that exist in utilization and materials selection are described. Methods of heat extraction and the environmental concerns that accompany geothermal fluid development are briefly described. Governmental rules, regulations and legislation are explained. The time and steps necessary to bring about the development of the geothermal resource are explained in detail. Some of the federal incentives that encourage the use of geothermal energy are summarized. (MHR)

  15. Geothermal resource and utilization in Bulgaria

    International Nuclear Information System (INIS)

    Bojadgieva, K.; Benderev, A.

    2011-01-01

    Bulgarian territory is rich in thermal water of temperature in the range of 20 - 100 o C. The highest water temperature (98 o C) is measured in Sapareva banya geothermal reservoir. Electricity generation from geothermal water is not currently available in the country. The major direct thermal water use nowadays covers: balneology, space heating and air-conditioning, domestic hot water supply, greenhouses, swimming pools, bottling of potable water and geothermal ground source heat pumps (GSHP). The total installed capacity amounts to about 77.67 MW (excl. GSHP) and the produced energy is 1083.89 TJ/year. Two applications - balneology and geothermal ground source heat pumps show more stable development during the period of 2005 - 2010. The update information on the state-owned hydrothermal fields is based on issued permits and concessions by the state.

  16. Design of a Geothermal Downhole Magnetic Flowmeter

    Energy Technology Data Exchange (ETDEWEB)

    Glowka, Dave A.; Normann, Randy A.

    2015-06-15

    This paper covers the development of a 300°C geothermal solid-state magnetic flowmeter (or magmeter) to support in situ monitoring of future EGS (enhanced geothermal system) production wells. Existing flowmeters are simple mechanical spinner sensors. These mechanical sensors fail within as little as 10 hrs, while a solid-state magmeter has the potential for months/years of operation. The design and testing of a magnetic flow sensor for use with existing high-temperature electronics is presented.

  17. Initial temperature distribution in Los Humeros, Mexico, geothermal field; Distribucion de temperatura inicial en el campo geotermico de Los Humeros, Puebla

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, A; Arellano, V; Aragon, A; Barragan, R.M; Izquierdo, G [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Pizano, A [Comision federal de Electricidad, Los Humeros, Puebla (Mexico)

    2000-12-01

    The initial formation temperatures surrounding 40 wells from the Los Humeros geothermal field are presented. These temperatures were estimated using the Horner and the sphere methods. A brief discussion on the applicability of each method is presented and previous applications are detailed. Then the more likely reservoir temperature of each well versus elevation is plotted based on the estimations about the main feed zone and the temperature of each well. The boiling with depth curve for pure water is also included. Two longitudinal and one traverse geological sections are presented to illustrate the field initial temperature distribution, the lithology and layers thickness, the basement topography and the wells traversed along each sections. Also, the main feed zones of the wells are indicated. Finally, the last series of measured temperature logs in well H-26 are produced by numerical simulation. This considers the well circulation losses and an assumed initial temperature profile. This profile iteratively modified until the computed profiles match the measured temperature profiles. The last assumed temperature profile is then considered as the best approximation to the undisturbed formation temperature around well H-26 and it is then compared with the stabilized temperatures obtained via the Horner and Sphere methods. [Spanish] Se presentan las temperaturas iniciales o estabilizadas de la formacion circundante a 40 pozos del campo geotermico Los Humeros, las cuales se estimaron mediante los metodos de Horner y el metodo de la esfera. Se presenta una discusion sobre la aplicacion de cada metodo y se detallan las aplicaciones previas del metodo de la esfera. Posteriormente y con base en las estimaciones de las principales zonas de aporte de cada pozo y sus correspondientes temperaturas se grafican las temperaturas mas probables de yacimiento para cada pozo contra la elevacion y se incluye en la misma grafica la curva de ebullicion del agua contra la elevacion. Se

  18. Studies of geothermal background and isotopic geochemistry of thermal waters in Jiangxi Province

    International Nuclear Information System (INIS)

    Zhou Wenbin; Sun Zhanxue; Li Xueli; Shi Weijun

    1996-10-01

    The terrestrial heat flow measurement, isotope and geochemical techniques have been systematically applied to the geothermal systems in Jiangxi Province. Results show that the thermal waters in the study area all belong to the low-medium temperature convective geothermal system, which essentially differs from high temperature geothermal systems with deep magmatic heat sources. It has been proven that the isotope and geochemical techniques are very useful and effective in geothermal exploration. (13 refs., 14 tabs., 8 figs.)

  19. Geothermal resources in the Republic of Macedonia

    International Nuclear Information System (INIS)

    Micevski, Eftim; Georgieva, Mirjana; Petrovski, Kiro; Lonchar, Ilija

    1995-01-01

    The Republic of Macedonia is situated in the central part of the Balcan Peninsula and covers a surface of 25. 713 km 2 Its territory is found in one of the most significant geothermal zones in this part of Balkans. The earths crust in this region suffers poli phase structural deformations, which as a result gives different structural features. The geothermal explorations in the Republic of Macedonia intensively started to conduct after 1970, after the first effects of the energy crisis. As a result of these explorations, more than 50 springs of mineral and thermo mineral waters with a total yield of more than 1.400 I./sec. And proved exploitation reservoirs of more than 1.000 I./sec. with temperatures higher than the medium year seasons hesitations for this part of the Earth in the boundaries of 20-75 o C with significant quantities of geothermal energy. This paper will shortly present the available geothermal resources and classification, according the type of geothermal energy, hydro geothermal, lithogeothermal and according the way of transport of the geothermal energy, convective and conductive systems. The next will present short descriptions of the resources, the degree of exploitation and the prognosis dimensions of the reservoirs. (Original)

  20. Deep Geothermal Energy Production in Germany

    Directory of Open Access Journals (Sweden)

    Thorsten Agemar

    2014-07-01

    Full Text Available Germany uses its low enthalpy hydrothermal resources predominantly for balneological applications, space and district heating, but also for power production. The German Federal government supports the development of geothermal energy in terms of project funding, market incentives and credit offers, as well as a feed-in tariff for geothermal electricity. Although new projects for district heating take on average six years, geothermal energy utilisation is growing rapidly, especially in southern Germany. From 2003 to 2013, the annual production of geothermal district heating stations increased from 60 GWh to 530 GWh. In the same time, the annual power production increased from 0 GWh to 36 GWh. Currently, almost 200 geothermal facilities are in operation or under construction in Germany. A feasibility study including detailed geological site assessment is still essential when planning a new geothermal facility. As part of this assessment, a lot of geological data, hydraulic data, and subsurface temperatures can be retrieved from the geothermal information system GeotIS, which can be accessed online [1].

  1. Geothermal fields of China

    Science.gov (United States)

    Kearey, P.; HongBing, Wei

    1993-08-01

    There are over 2500 known occurrences of geothermal phenomena in China. These lie mainly in four major geothermal zones: Xizang (Tibet)-Yunnan, Taiwan, East Coast and North-South. Hot water has also been found in boreholes in major Mesozoic-Cenozoic sedimentary basins. This paper presents a summary of present knowledge of these geothermal zones. The geological settings of geothermal occurrences are associated mainly with magmatic activity, fault uplift and depressional basins and these are described by examples of each type. Increased multipurpose utilisation of geothermal resources is planned and examples are given of current usages.

  2. World geothermal congress

    International Nuclear Information System (INIS)

    Povarov, O.A.; Tomarov, G.V.

    2001-01-01

    The World geothermal congress took place in the period from 28 May up to 10 June 2000 in Japan. About 2000 men from 43 countries, including specialists in the area of developing geothermal fields, creating and operating geothermal electrical and thermal plants and various systems for the earth heat application, participated in the work of the Congress. It was noted at the Congress, that development of the geothermal power engineering in the world is characterized by the large-scale application of geothermal resources for the electrical energy generation [ru

  3. Hawaii geothermal project

    Science.gov (United States)

    Kamins, R. M.

    1974-01-01

    Hawaii's Geothermal Project is investigating the occurrence of geothermal resources in the archipelago, initially on the Island of Hawaii. The state's interest in geothermal development is keen, since it is almost totally dependent on imported oil for energy. Geothermal development in Hawaii may require greater participation by the public sector than has been true in California. The initial exploration has been financed by the national, state, and county governments. Maximization of net benefits may call for multiple use of geothermal resources; the extraction of by-products and the application of treated effluents to agricultural and aquacultural uses.

  4. Geothermal studies of seven interior salt domes

    International Nuclear Information System (INIS)

    1983-06-01

    This report defines and compares the geothermal environments of eight selected Gulf Coast salt domes. The thermal regimes in and around Gulf Coast salt domes are not well documented. The data base used for this study is an accumulation of bottom-hole temperature readings from oil and gas exploration wells and temperature logs run for the National Waste Terminal Storage (NWTS) program. The bottom-hole tempreatures were corrected in order to estimate the actual geothermal environments. Prior thermal studies and models indicate temperatures in and around salt domes are elevated above the norm by 1 0 F to 25 0 F. Using existing geothermal data and accepted theory, geothermal gradients for the selected domes and surrounding sediments were estimated. This study concludes that salt domes within a given basin have similar geothermal gradients, but that the basins differ in average geothermal gradients. This relationship is probably controlled by deep basement structural trends. No evidence of residual heat of emplacement was found associated with any of the selected domes

  5. Ultra high-temperature solids-free insulating packer fluid for oil and gas production, steam injection and geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Ezell, R.G.; Harrison, D.J. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Halliburton Energy Services, Calgary, AB (Canada)

    2008-10-15

    Uncontrolled heat transfer from production/injection tubing during thermal oil recovery via steam injection can be detrimental to the integrity of the casing and to the quality of the steam that is injected into the reservoir. An aqueous-based insulating packer fluid (IPF) was introduced to improve the steam injection process by controlling the total heat loss from the produced fluids to the surrounding wellbore, internal annuli and formation. The IPF was developed for elevated temperature environments through extensive investigation across multidisciplinary technology. The innovative system delivers performance beyond conventional systems of comparable thermal conductivity. Its density range and conductivity measurements were presented in this paper. High-temperature static aging tests showed superior gel integrity without any phase separation after exposure to temperatures higher than 260 degrees C. The new fluids are hydrate inhibitive, non-corrosive and pass oil and grease testing. They are considered to be environmentally sound by Gulf of Mexico standards. It was concluded that the new ultra high-performance insulating packer fluid (HTIPF) reduced the heat loss significantly by both conduction and convection. Heat transfer within the aqueous-based HTIPF was 97 per cent less than that of pure water. It was concluded that the HTIPF can be substituted for conventional packer fluids without compromising any well control issues. 21 refs., 1 tab., 4 figs.

  6. Microbiological Monitoring in Geothermal Plants

    Science.gov (United States)

    Alawi, M.; Lerm, S.; Linder, R.; Vetter, A.; Vieth-Hillebrand, A.; Miethling-Graff, R.; Seibt, A.; Wolfgramm, M.; Wuerdemann, H.

    2010-12-01

    In the scope of the research projects “AquiScreen” and “MiProTherm” we investigated geothermally used groundwater systems under microbial, geochemical, mineralogical and petrological aspects. On one side an enhanced process understanding of engineered geothermal systems is mandatory to optimize plant reliability and economy, on the other side this study provides insights into the microbiology of terrestrial thermal systems. Geothermal systems located in the North German Basin and the Molasse Basin were analyzed by sampling of fluids and solid phases. The investigated sites were characterized by different temperatures, salinities and potential microbial substrates. The microbial population was monitored by the use of genetic fingerprinting techniques and PCR-cloning based on PCR-amplified 16S rRNA and dissimilatory sulfite reductase (DSR) genes. DNA-sequences of fingerprints and cloned PCR-products were compared to public databases and correlated with metabolic classes to provide information about the biogeochemical processes. In all investigated geothermal plants, covering a temperature range from 5° to 120°C, microorganisms were found. Phylogenetic gene analyses indicate a broad diversity of microorganisms adapted to the specific conditions in the engineered system. Beside characterized bacteria like Thermus scotoductus, Siderooxidans lithoautotrophicus and the archaeon Methanothermobacter thermoautotrophicus a high number of so far uncultivated microorganisms was detected. As it is known that - in addition to abiotic factors - microbes like sulfate-reducing bacteria (SRB) are involved in the processes of corrosion and scaling in plant components, we identified SRB by specific analyses of DSR genes. The SRB detected are closely related to thermotolerant and thermophilic species of Desulfotomaculum, Thermodesulfovibrio, Desulfohalobium and Thermodesulfobacterium, respectively. Overall, the detection of microbes known to be involved in biocorrosion and the

  7. The geothermal system of Caviahue-Copahue Volcanic Complex (Chile-Argentina): New insights from self-potential, soil CO2 degassing, temperature measurements and helium isotopes, with structural and fluid circulation implications.

    Science.gov (United States)

    Roulleau, Emilie; Bravo, Francisco; Barde-Cabusson, Stephanie; Pizarro, Marcela; Muños, Carlos; Sanchez, Juan; Tardani, Daniele; Sano, Yuji; Takahata, Naoto; de Cal, Federico; Esteban, Carlos

    2016-04-01

    Geothermal systems represent natural heat transfer engines in a confined volume of rock which are strongly influenced by the regional volcano-tectonic setting controlling the formation of shallow magmatic reservoirs, and by the local faults/fracture network, that permits the development of hydrothermal circulation cells and promote the vertical migration of fluids and heat. In the Southern Volcanic Zone of Chile-Argentina, geothermal resources occur in close spatial relationship with active volcanism along the Cordillera which is primarily controlled by the 1000 km long, NNE Liquiñe-Ofqui Fault Zone (LOFZ), an intra-arc dextral strike-slip fault system, associated with second-order intra-arc anisotropy of overall NE-SW (extensional) and NW-SE orientation (compressional). However there is still a lack of information on how fault network (NE and WNW strinking faults) and lithology control the fluid circulation. In this study, we propose new data of dense self-potential (SP), soil CO2 emanation and temperature (T) measurements within the geothermal area from Caviahue-Copahue Volcanic Complex (CCVC), coupled with helium isotopes ratios measured in fumaroles and thermal springs. We observe that inside the geothermal system the NE-striking faults, characterized by a combination of SP-CO2 and T maxima with high 3He/4He ratios (7.86Ra), promote the formation of high vertical permeability pathways for fluid circulation. Whereas, the WNW-striking faults represent low permeability pathways for hydrothermal fluids ascent associated with moderate 3He/4He ratios (5.34Ra), promoting the infiltration of meteoric water at shallow depth. These active zones are interspersed by SP-CO2- T minima, which represent self-sealed zones (e.g. impermeable altered rocks) at depth, creating a barrier inhibiting fluids rise. The NE-striking faults seem to be associated with the upflow zones of the geothermal system, where the boiling process produces a high vapor-dominated zone close to the

  8. Geothermal for kids

    International Nuclear Information System (INIS)

    Nemzer, M.; Condy, M.

    1990-01-01

    This paper reports that educating children about geothermal energy is crucial to the future growth of the geothermal industry. The Geothermal Education Office (GEO) was founded in 1989 to provide materials and support to teachers and the geothermal community in educating grades K-12 about geothermal energy. GEO's goals are to: provide easy access to or referral to appropriate sources of geothermal information; foster teacher interest; create posters, booklets, lesson plans and other educational materials; monitor and review textbooks, encyclopedias and other educational materials distributed by educational groups to ensure inclusion of appropriate, accurate information and to encourage fair treatment of alternative energy resources; contribute articles to industry, science and educational publications; and foster communication and cooperation among GEO, the geothermal industry, government agencies, and educational and environmental groups

  9. Geothermal energy in Jordan

    International Nuclear Information System (INIS)

    Al-Dabbas, Moh'd A. F.

    1993-11-01

    The potential of geothermal energy utilization in Jordan was discussed. The report gave a summary of the location of geothermal anomalies in Jordan, and of ongoing projects that utilize geothermal energy for greenhouse heating, fish farming, refrigeration by absorption, and water desalination of deep aquifers. The problems facing the utilization of geothermal energy in Jordan were identified to be financial (i.e. insufficient allocation of local funding, and difficulty in getting foreign financing), and inadequate expertise in the field of geothermal energy applications. The report gave a historical account of geothermal energy utilization activities in Jordan, including cooperation activities with international organizations and foreign countries. A total of 19 reports already prepared in the areas of geochemical and hydrological studies were identified. The report concluded that the utilization of geothermal energy offers some interesting economic possibilities. (A.M.H.). 4 refs. 1 map

  10. Classification of public lands valuable for geothermal steam and associated geothermal resources

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, L.H.; Haigler, L.B.; Rioux, R.L.; White, D.E.; Muffler, L.J.P.; Wayland, R.G.

    1973-01-01

    The Organic Act of 1879 (43 USC 31) that established the US Geological Survey provided, among other things, for the classification of the public lands and for the examination of the geological structure, mineral resources, and products of the national domain. In order to provide uniform executive action in classifying public lands, standards for determining which lands are valuable for mineral resources, for example, leasable mineral lands, or for other products are prepared by the US Geological Survey. This report presents the classification standards for determining which Federal lands are classifiable as geothermal steam and associated geothermal resources lands under the Geothermal Steam Act of 1970 (84 Stat. 1566). The concept of a geothermal resouces province is established for classification of lands for the purpose of retention in Federal ownership of rights to geothermal resources upon disposal of Federal lands. A geothermal resources province is defined as an area in which higher than normal temperatures are likely to occur with depth and in which there is a resonable possiblity of finding reservoir rocks that will yield steam or heated fluids to wells. The determination of a known geothermal resources area is made after careful evaluation of the available geologic, geochemical, and geophysical data and any evidence derived from nearby discoveries, competitive interests, and other indicia. The initial classification required by the Geothermal Steam Act of 1970 is presented.

  11. Chemical conditions of the Japanese neutral geothermal reservoirs

    International Nuclear Information System (INIS)

    Chiba, H.

    1991-01-01

    The aqueous speciation were calculated for fluids of seven Japanese geothermal systems. The aqueous composition as well as CO 2 partial pressure of fluid in neutral pH geothermal reservoir are controlled by silicate, calcite and anhydrite minerals. The chemical composition of neutral pH geothermal reservoir can be predictable if two parameters (e.g. temperature and one of the cation activities) are provided. (author)

  12. The low-energy geothermics

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Low-energy geothermal resources are characterized by temperatures ranging from 30 to 100 C. The principal worldwide applications are: towns and greenhouses heating, spa bathing, agriculture products drying, etc.. Sources depth ranges from 1500 to 2500 m in porous and permeable formations (sandstones, sands, conglomerates, limestones..) carrying aquifers. The worldwide installed power was of about 11500 MWth in 1990, with an annual production of about 36000 GWh (about 1% of worldwide energy consumption). The annual production rate is estimated to 10% and would represent a 30000 and 80000 MWth power in 2000 and 2010, respectively. In France, low-energy geothermal resources are encountered principally in Mesozoic sediments of the Parisian and Aquitanian basins. French geothermics has developed during the last 30 years and principally between 1980 and 1985 after the second petroleum crack. After 1985, the decay of fossil fuel costs and the development of corrosion problems in the geothermal wells have led to the abandonment of the less productive fields and to the study of technical solutions to solve the corrosion problems. (J.S.). 1 fig., 5 photos

  13. Investigation of origin, subsurface processes and reservoir temperature of geothermal springs around Koh-i-Sultan volcano, Chagai, Pakistan

    International Nuclear Information System (INIS)

    Ahmad, M.; Rafique, M.; Iqbal, N.; Fazil, M.

    2009-07-01

    In Chagai area, seven springs with maximum surface temperature of 32.2 deg. C located in the vicinity of Miri Crater of Koh-i-Sultan Volcano were investigated using isotope and chemical techniques. Two springs of Padagi Kaur are MgSO/sub 4/ type, while all the other springs at Batal Kaur, Miri Kaur and Chigin Dik are Na-Cl type. Alteration of water to SO/sub 4/ type takes place by absorption of magmatic H/sub 2/S and the acidic solution is further responsible to dissolve rock salt and carbonate minerals. EC increases from Padagi springs (4940 and 8170 S/cm) to Chigin Dik springs (45600 S/cm). Chagai thermal manifestations receive recharge from meteoric waters in the vicinity of Padagi Kaur (east side of Miri Crater), which is heated by the hot magma chamber of Koh-i-Sultan most probably through deep circulation. Movement of the thermal water is from Miri Crater towards Chigin Dik area. Residence time is more than 60 years. The thermal waters do not have any contribution of shallow young groundwater and they have high 1/sup 8/O-shift (6 to 8%) due to rock-water interaction. Reservoir temperatures estimated by different chemical geo thermometers like Na-K, Na-K-Ca, Na-K-Mg 1/2 (triangular plot) are quite high (200-300 deg. C), while the silica and (SO/sub 4/-H/sub 2/O) geo thermometers give relatively low temperature ranges (107-144 deg. C and 112-206 deg. C respectively). (author)

  14. Rapid precipitation of silica (opal-A) disguises evidence of biogenicity in high-temperature geothermal deposits: Case study from Dagunguo hot spring, China

    Science.gov (United States)

    Peng, Xiaotong; Jones, Brian

    2012-06-01

    Dagunguo Spring, located in the Tengchong geothermal area in the western part of Yunnan Province, China, is a very active spring with water temperatures of 78 to 97 °C and pH of 7.7 to 8.8. The vent pool, 5.6 m in diameter and up to 1.5 m deep, is lined with opal-A that was precipitated from the near-boiling spring waters. A glass suspended in the pool was coated with opal-A in two months and two PVC pipes that drained water from the pool in late 2010 became lined with opal-A precipitates in less than three months. The opal-A accumulated at rates of 0.5 to 0.75 mm/month in the spring pool and 2.5 to 3.5 mm/month in the PVC pipes. The opal-A precipitates, irrespective of where they developed, are formed primarily of silicified microbes and opal-A spheres along with minor amounts of native sulfur, detrital quartz, and clay (mainly kaolinite). The fabrics in these opal-A deposits were dictated largely by the growth patterns of the filamentous and rod-shaped microbes that dominate this low-diversity biota and the amount of opal-A that was precipitated around them. Many of the microbes were preserved as rapid opal-A was precipitated on and around them before the cells decayed. With continued precipitation, however, the microbes became quickly engulfed in the opal-A precipitates and morphological evidence of their presence was lost. In essence, the process that controls their preservation ultimately disguised them to the point where cannot be seen. Critically, this loss of morphological identity takes places even before opal-A starts its diagenetic transformation towards quartz.

  15. Constraints on Alpine Fault (New Zealand) Mylonitization Temperatures and Geothermal Gradient from Ti-in-quartz Thermobarometry

    OpenAIRE

    Kidder, Steven; Toy, Virginia; Prior, Dave; Little, Tim; MacRae, Colin

    2018-01-01

    We constrain the thermal state of the central Alpine Fault using approximately 750 Ti-in-quartz SIMS analyses from a suite of variably deformed mylonites. Ti-in-quartz concentrations span more than an order of magnitude from 0.24 to ~5 ppm, suggesting recrystallization of quartz over a 300° range in temperature. Most Ti-in-quartz concentrations in mylonites, protomylonites, and the Alpine Schist protolith are between 2 and 4 ppm and do not vary as a function of grain size or bul...

  16. Ground-air temperature tracking and multi-year cycles in the subsurface temperature time series at geothermal climat e-change observatory

    Czech Academy of Sciences Publication Activity Database

    Čermák, Vladimír; Bodri, L.; Šafanda, Jan; Krešl, Milan; Dědeček, Petr

    2014-01-01

    Roč. 58, č. 3 (2014), s. 406-424 ISSN 0039-3169 R&D Projects: GA ČR(CZ) GAP210/11/0183; GA AV ČR KSK3046108 Institutional support: RVO:67985530 Keywords : borehole observatory * temperature monitoring * climate change * subsurface temperature Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.806, year: 2014

  17. The Campi Flegrei caldera-hosted high-temperature and high-saline geothermal system in the Southern Italy: the implication of the geothermal resource as derived by the present state of the knowledge through 70 years of volcanological, structural, petrolog

    Science.gov (United States)

    Piochi, M.; Di Vito, M. A.; Mormone, A.; De Natale, G.; Tramelli, A.; Troise, C.; Carlino, S.

    2012-04-01

    The Campi Flegrei caldera (Italy) hosts a geothermal system characterized by: i) high thermal gradient (temperature up to 420°C at 3050 m b.s.l.), ii) high temperature (up to ~90-150°C at very shallow depth) fumaroles, iii) multiple meteoric to brine (TDS up to 33 g•l-1; temperature up to 95 °C) aquifers and iv) at least 1500 tonnes per day of CO2 emissions. This area is highly urbanized despite the repeated occurrence of ground deformation phenomena accompanied by seismicity with volcano-tectonic and long-period micro-earthquakes. The caldera has been widely studied by geologist and geophysicists. In particular, since '40s, the caldera has drawn scientific interest for its geothermal capability inducing the companies AGIP (Azienda Geologica Italiana Petroli) and SAFEN (Società Anonima Forze Endogene Napoletane) to drill more than one hundred 80-to-3100 m deep wells. However this experience did not reach the exploitation phase due to technological and communication problems. The geothermal potential (thermal and electric) is evaluated of about 6 GWy. The recent Campi Flegrei Deep Drilling Project [De Natale and Troise, 2011], sponsored by the International Continental Scientific Drilling Program, foresees the realization of medium-to-deep wells in the caldera with the ambition of stimulating interest in geothermal energy exploitation and technology development and, in addition of installing downhole monitoring systems. The geological knowledge of the area is the benchmark for the drilling sites selection. We reconstructed a multi-disciplinary conceptual model updated on the basis of the most recent scientific results and findings. In particular, the constrains (the most important are listed in brackets) comes from: i) boreholes (litho-stratigraphy, aquifer location, depth-related temperature), ii) fieldwork (stratigraphy, location of structural fractures and eruption vents), iii) petrology and melt inclusions (pressure and temperature of magma with

  18. Numerical investigation of the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir: a case study of the Daming geothermal field in China.

    Science.gov (United States)

    Guo, Xuyang; Song, Hongqing; Killough, John; Du, Li; Sun, Pengguang

    2018-02-01

    The utilization of geothermal energy is clean and has great potential worldwide, and it is important to utilize geothermal energy in a sustainable manner. Mathematical modeling studies of geothermal reservoirs are important as they evaluate and quantify the complex multi-physical effects in geothermal reservoirs. However, previous modeling efforts lack the study focusing on the emission reduction efficiency and the deformation at geothermal wellbores caused by geothermal water extraction/circulation. Emission efficiency is rather relevant in geothermal projects introduced in areas characterized by elevated air pollution where the utilization of geothermal energy is as an alternative to burning fossil fuels. Deformation at geothermal wellbores is also relevant as significant deformation caused by water extraction can lead to geothermal wellbore instability and can consequently decrease the effectiveness of the heat extraction process in geothermal wells. In this study, the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir in Daming County, China, are numerically investigated based on a coupled multi-physical model. Relationships between the efficiency of emission reduction and heat extraction, deformation at geothermal well locations, and geothermal field parameters including well spacing, heat production rate, re-injection temperature, rock stiffness, and geothermal well placement patterns are analyzed. Results show that, although large heat production rates and low re-injection temperatures can lead to decreased heat production in the last 8 years of heat extraction, they still improve the overall heat production capacity and emission reduction capacity. Also, the emission reduction capacity is positively correlated with the heat production capacity. Deformation at geothermal wellbore locations is alleviated by smaller well spacing, lower heat production rates, and smaller numbers of injectors in the well pattern, and by

  19. Geothermal probes for the development of medium-deep geothermal heating; Erdwaermesonden zur Erschliessung der mitteltiefen Geothermie

    Energy Technology Data Exchange (ETDEWEB)

    Stuckmann, Uwe [REHAU AG + Co, Erlangen (Germany)

    2012-07-01

    Compared to the near-surface geothermal energy, in the medium-deep geothermal between between 400 and 1,000 meters higher temperature levels may opened up. Thus the efficiency of geothermal power plants can be increased. The possibly higher installation costs are significantly higher yield compared to the yields and withdrawal benefits. At higher thermal gradient of the underground it even is possible to dispense entirely on the heat pump and to heat directly.

  20. Models of Geothermal Brine Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Nancy Moller Weare; John H. Weare

    2002-03-29

    Many significant expenses encountered by the geothermal energy industry are related to chemical effects. When the composition, temperature of pressure of the fluids in the geological formation are changed, during reservoir evolution, well production, energy extraction or injection processes, the fluids that were originally at equilibrium with the formation minerals come to a new equilibrium composition, temperature and pressure. As a result, solid material can be precipitated, dissolved gases released and/or heat lost. Most geothermal energy operations experience these phenomena. For some resources, they create only minor problems. For others, they can have serious results, such as major scaling or corrosion of wells and plant equipment, reservoir permeability losses and toxic gas emission, that can significantly increase the costs of energy production and sometimes lead to site abandonment. In future operations that exploit deep heat sources and low permeability reservoirs, new chemical problems involving very high T, P rock/water interactions and unknown injection effects will arise.

  1. Geothermal potential of northern Bavaria: Analysis of geothermal resources by evaluation of geophysical temperature logs in drinking water wells and deep wells; Geothermisches Potential Nordbayerns - Untersuchungen der geothermischen Verhaeltnisse durch Auswertung geophysikalischer Temperaturmessungen in Trinkwasser- und Tiefbohrungen

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, W; Udluft, P [Lehr- und Forschungsbereich Hydrogeologie und Umwelt, Inst. fuer Geologie, Wuerzburg Univ. (Germany)

    1997-12-01

    The geothermal potential of northern Bavaria was investigated. Thermal water in the lower heat range may be used, e.g., for space heating, bath heating and agricultural purposes. Geophysical data were obtained from a number of drinking water wells with a depth of less than 150 m and a few deep wells of more than 150 m. The data are to serve as a decision aid for potential users of geothermal energy and reduce the exploration risk. (orig.) [Deutsch] Zielsetzung des Forschungsvorhabens ist die Bewertung des geothermischen Potentials Nordbayerns im Hinblick auf die Nutzung von Tiefenwasser zur Gewinnung von hydrothermaler Energie. Niedrigthermale Tiefenwaesser bieten sich z.B. als Energietraeger fuer Raumwaerme, Baederheizung and landwirtschaftliche Nutzung an. Die geothermischen Daten liegen in Form von geophysikalischen Temperaturmessungen aus zahlreichen Trinkwasserbohrungen mit weniger als 150 m Bohrtiefe und einigen Tiefbohrungen mit mehr als 150 m Bohrtiefe vor. Die Bewertung des geothermischen Potentials Nordbayerns soll als Planungsgrundlage fuer potentialle Erdwaermenutzer dienen und zu einer Minimierung des Explorationsrisikos beitragen. (orig.)

  2. Non-electrical uses of geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Barbier, E; Fanelli, M

    1977-01-01

    The non-electric applications of geothermal energy, with the exception of balneology, date back to the nineteenth century and have been given a new impetus by the recent oil crisis. In general, water or water-steam mixtures at temperatures between 20 and 180/sup 0/C are used for these applications. The search for geothermal fluids draws on techniques from hydrogeology, geochemistry and geophysics, the same techniques as applied to the search for cold waters, together with some specific methods connected with the underground thermal conditions. Geothermal energy is used in agriculture, aquaculture, district heating and cooling and various industrial applications. The power associated with these uses throughout the world at present can be estimated at 6200 MW and future prospects are by now promising and of definite economic interest. The environmental impact from geothermal energy is lower than that caused by conventional energy sources. Reinjection of used fluids back into the underground may, however, solve pollution problems.

  3. Non-electrical uses of geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Barbier, E; Fanelli, M

    1977-01-01

    The non-electric applications of geothermal energy, with the exception of balneology, date back to the nineteenth century and have been given a new impetus by the recent oil crisis. In general, water or water--steam mixtures at temperatures between 20 and 180/sup 0/C are used for these applications. The search for geothermal fluids draws on techniques from hydrogeology, geochemistry and geophysics, the same techniques as applied to the search for cold waters, together with some specific methods connected with the underground thermal conditions. Geothermal energy is used in agriculture, aquaculture, district heating and cooling, and various industrial applications. The power associated with these uses throughout the world at present can be estimated at 6200 MW and future prospects are by now promising and of definite economic interest. The environmental impact from geothermal energy is lower than that caused by conventional energy sources. Reinjection of used fluids back into the underground may, however, solve pollution problems.

  4. Annotated geothermal bibliography of Utah

    Energy Technology Data Exchange (ETDEWEB)

    Budding, K.E.; Bugden, M.H. (comps.)

    1986-01-01

    The bibliography includes all the Utah geothermal references through 1984. Some 1985 citations are listed. Geological, geophysical, and tectonic maps and reports are included if they cover a high-temperature thermal area. The references are indexed geographically either under (1) United States (national studies), (2) regional - western United States or physiographic province, (3) Utah - statewide and regional, or (4) county. Reports concerning a particular hot spring or thermal area are listed under both the thermal area and the county names.

  5. Geothermal heat pumps - Trends and comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W

    1989-01-01

    Heat pumps are used where geothermal water or ground temperatures are only slightly above normal, generally 50 to 90 deg. F. Conventional geothermal heating (and cooling) systems are not economically efficient at these temperatures. Heat pumps, at these temperatures, can provide space heating and cooling, and with a desuperheater, domestic hot water. Two basic heat pump systems are available, air-source and water- or ground-source. Water- and ground-coupled heat pumps, referred to as geothermal heat pumps (GHP), have several advantages over air-source heat pumps. These are: (1) they consume about 33% less annual energy, (2) they tap the earth or groundwater, a more stable energy source than air, (3) they do not require supplemental heat during extreme high or low outside temperatures, (4) they use less refrigerant (freon), and (5) they have a simpler design and consequently less maintenance.

  6. Preliminary geothermal study of Mt. Etna

    Energy Technology Data Exchange (ETDEWEB)

    Mongelli, F; Morelli, C

    1964-01-01

    The geothermal status of Italy's Mt. Etna region was studied via borehole thermometry at eight experimental sites. The mathematical principles and other criteria used in borehole site and well depth selection are discussed. The soil temperature is regulated by external temperature variations to a certain depth. The minimum drilling distance which would provide accurate temperature determinations was calculated to be 30 m. The geothermal gradient was determined by the application of a Fourier series to three measurements made at different depths using resistance thermometers. The results are presented in tables and the gradients are plotted on graphs. Geothermal gradient determinations were corrected for topographic effects. Two major groups of gradients were discovered, those having linear gradients were interpreted as being due to the effect of meteoric waters. Other possible disturbances are those caused by surface temperature effects and the influence of nearby bodies of water.

  7. Operation strategy analysis of a geothermal step utilization heating system

    International Nuclear Information System (INIS)

    Zheng, Guozhong; Li, Feng; Tian, Zhe; Zhu, Neng; Li, Qianru; Zhu, Han

    2012-01-01

    Geothermal energy has been successfully applied in many district heating systems. In order to promote better use of geothermal energy, it is important to analyze the operation strategy of geothermal heating system. This study proposes a comprehensive and systematic operation strategy for a geothermal step utilization heating system (GSUHS). Calculation models of radiator heating system (RHS), radiant floor heating system (RFHS), heat pump (HP), gas boiler (GB), plate heat exchanger (PHE) and pump are first established. Then the operation strategy of the GSUHS is analyzed with the aim to substantially reduce the conventional energy consumption of the whole system. Finally, the energy efficiency and geothermal tail water temperature are analyzed. With the operation strategy in this study, the geothermal energy provides the main heating amount for the system. The heating seasonal performance factor is 15.93. Compared with coal-fired heating, 75.1% of the standard coal equivalent can be saved. The results provide scientific guidance for the application of an operation strategy for a geothermal step utilization heating system. -- Highlights: ► We establish calculation models for the geothermal step utilization heating system. ► We adopt minimal conventional energy consumption to determine the operation strategy. ► The geothermal energy dominates the heating quantity of the whole system. ► The utilization efficiency of the geothermal energy is high. ► The results provide guidance to conduct operation strategy for scientific operation.

  8. Aerated drilling cutting transport analysis in geothermal well

    Science.gov (United States)

    Wakhyudin, Aris; Setiawan, Deni; Dwi Marjuan, Oscar

    2017-12-01

    Aeratad drilling widely used for geothermal drilling especially when drilled into predicted production zone. Aerated drilling give better performance on preventing lost circulation problem, improving rate of penetration, and avoiding drilling fluid invasion to productive zone. While well is drilled, cutting is produced and should be carried to surface by drilling fluid. Hole problem, especially pipe sticking will occur while the cutting is not lifted properly to surface. The problem will effect on drilling schedule; non-productive time finally result more cost to be spent. Geothermal formation has different characteristic comparing oil and gas formation. Geothermal mainly has igneous rock while oil and gas mostly sedimentary rock. In same depth, formation pressure in geothermal well commonly lower than oil and gas well while formation temperature geothermal well is higher. While aerated drilling is applied in geothermal well, Igneous rock density has higher density than sedimentary rock and aerated drilling fluid is lighter than water based mud hence minimum velocity requirement to transport cutting is larger than in oil/gas well drilling. Temperature and pressure also has impact on drilling fluid (aerated) density. High temperature in geothermal well decrease drilling fluid density hence the effect of pressure and temperature also considered. In this paper, Aerated drilling cutting transport performance on geothermal well will be analysed due to different rock and drilling fluid density. Additionally, temperature and pressure effect on drilling fluid density also presented to merge.

  9. Initial distribution of pressure and temperature in the geothermal field of Los Humeros, Puebla; Distribucion inicial de presion y temperatura del campo geotermico de Los Humeros, Puebla

    Energy Technology Data Exchange (ETDEWEB)

    Arellano Gomez, Victor M.; Garcia Gutierrez, Alfonso; Barragan Reyes, Rosa Maria; Aragon Aguilar, Alfonso; Pizano, Arturo [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2000-07-01

    In order to infer the distributions of non disturbed pressure and temperature of the reservoir fluid, a considerable amount of information originating from several disciplines was analyzed, corresponding to 42 wells of the geothermal field of Los Humeros. On the base of the analyzed data models were developed, in one and two dimensions, of the reservoir in an initial state. The models reveal the existence of at least two reservoirs. The first one and most superficial is located between 1600 and 1025 m.a.s.l. and it is a reservoir of dominant liquid. The pressure profile of this reservoir corresponds to a boiling water column approximately between 300 and 339 Celsius degrees. The second reservoir is located underneath the 850 m.a.s.l. and as far as the collected data, it can be said that it extends at least until the 100 m.a.s.l and it is estimated that it is a reservoir of low liquid saturation. For the wells that are fed from this zone of the field temperatures between 300 and 400 Celsius degrees were estimated. A table of the geology of the subsoil of the region of the Los Humeros is shown and a table where the chemical composition of the separated water is indicated and the enthalpy of some of the wells of Los Humeros, Puebla, Mexico. [Spanish] Para inferir las distribuciones de presion y temperatura no perturbadas del fluido del yacimiento, se analizo una considerable cantidad de informacion proveniente de varias disciplinas, correspondiente a 42 pozos del campo geotermico de Los Humeros. Sobre la base de los datos analizados se desarrollaron modelos, en una y dos dimensiones, del yacimiento en un estado inicial. Los modelos revelan la existencia de cuando menos dos yacimientos. El primero y mas superficial se encuentra localizado entre 1600 y 1025 m.s.n.m. y es un yacimiento de liquido dominante. El perfil de presion de este yacimiento corresponde a una columna de agua en ebullicion aproximadamente entre 300 y 339 grados centigrados. El segundo yacimiento se

  10. Synergy potential for oil and geothermal energy exploitation

    DEFF Research Database (Denmark)

    Ziabakhsh-Ganji, Zaman; Nick, Hamidreza M.; Donselaar, Marinus E.

    2018-01-01

    A new solution for harvesting energy simultaneously from two different sources of energy by combining geothermal energy production and thermal enhanced heavy oil recovery is introduced. Numerical simulations are employed to evaluate the feasibility of generating energy from geothermal resources...... and feasibility analyses of the synergy potential of thermally-enhanced oil recovery and geothermal energy production are performed. A series of simulations are carried out to examine the effects of reservoir properties on energy consumption and oil recovery for different injection rates and injection temperature...... the geothermal energy could make the geothermal business case independent and may be a viable option to reduce the overall project cost. Furthermore, the results display that the enhance oil productions are able to reduce the required subsidy for a single doublet geothermal project up to 50%....

  11. Trace element chemistry and textures of low-temperature pyrites associated with shallow fossil subsurface geothermal discharge in the Eger Graben, northwestern Bohemia

    Czech Academy of Sciences Publication Activity Database

    Zachariáš, J.; Adamovič, Jiří; Langrová, Anna

    2006-01-01

    Roč. 37, 29 (2006), s. 237-239 ISSN 0032-6267 R&D Projects: GA AV ČR IAA3013302 Institutional research plan: CEZ:AV0Z30130516 Keywords : pyrite * geothermal fluids * Eger Graben Subject RIV: DB - Geology ; Mineralogy

  12. Tapping the earth's geothermal resources: Hydrothermal today, magma tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    Kukacka, L.E.

    1986-12-17

    The paper discusses geothermal resources, what it is, where it is, and how to extract energy from it. The materials research activities at Brookhaven National Laboratory related to geothermal energy extraction are discussed. These include high-temperature, light-weight polymer cements, elastomers, biochemical waste processing techniques, and non-metallic heat exchanger tubing. The economics of geothermal energy is also discussed. (ACR)

  13. What is geothermal steam worth?

    International Nuclear Information System (INIS)

    Thorhallsson, S.; Ragnarsson, A.

    1992-01-01

    Geothermal steam is obtained from high-temperature boreholes, either directly from the reservoir or by flashing. The value of geothermal steam is similar to that of steam produced in boilers and lies in its ability to do work in heat engines such as turbines and to supply heat for a wide range of uses. In isolated cases the steam can be used as a source of chemicals, for example the production of carbon dioxide. Once the saturated steam has been separated from the water, it can be transported without further treatment to the end user. There are several constraints on its use set by the temperature of the reservoir and the chemical composition of the reservoir fluid. These constraints are described (temperature of steam, scaling in water phase, gas content of steam, well output) as are the methods that have been adopted to utilize this source of energy successfully. Steam can only be transported over relatively short distances (a few km) and thus has to be used close to the source. Examples are given of the pressure drop and sizing of steam mains for pipelines. The path of the steam from the reservoir to the end user is traced and typical cost figures given for each part of the system. The production cost of geothermal steam is estimated and its sensitivity to site-specific conditions discussed. Optimum energy recovery and efficiency is important as is optimizing costs. The paper will treat the steam supply system as a whole, from the reservoir to the end user, and give examples of how the site-specific conditions and system design have an influence on what geothermal steam is worth from the technical and economic points of view

  14. Energy efficiency comparison between geothermal power systems

    Directory of Open Access Journals (Sweden)

    Luo Chao

    2017-01-01

    Full Text Available The geothermal water which can be considered for generating electricity with the temperature ranging from 80℃ to 150℃ in China because of shortage of electricity and fossil energy. There are four basic types of geothermal power systems: single flash, double flash, binary cycle, and flash-binary system, which can be adapted to geothermal energy utilization in China. The paper discussed the performance indices and applicable conditions of different power system. Based on physical and mathematical models, simulation result shows that, when geofluid temperature ranges from 100℃ to 130℃, the net power output of double flash power is bigger than flash-binary system. When the geothermal resource temperature is between 130℃ and 150℃, the net power output of flash-binary geothermal power system is higher than double flash system by the maximum value 5.5%. However, the sum water steam amount of double flash power system is 2 to 3 times larger than flash-binary power system, which will cause the bigger volume of equipment of power system. Based on the economy and power capacity, it is better to use flash-binary power system when the geofluid temperature is between 100℃ and 150℃.

  15. Geothermal energy worldwide

    International Nuclear Information System (INIS)

    Barbier, Enriko

    1997-01-01

    Geothermal energy, as a natural steam and hot water, has been exploited for decades in order to generate electricity as well as district heating and industrial processes. The present geothermal electrical installed capacity in the world is about 10.000 MWe and the thermal capacity in non-electrical uses is about 8.200 MWt. Electricity is produced with an efficiency of 10-17%, and the cost of the kWh is competitive with conventional energy sources. In the developing countries, where a total installed electrical power is still low, geothermal energy can play a significant role: in El Salvador, for example, 25% of electricity comes from geothermal spring, 20% in the Philippines and 8% in Kenya. Present technology makes it possible to control the environmental impact of geothermal exploitation. Geothermal energy could also be extracted from deep geopressured reservoirs in large sedimentary basins, hot dry rock systems and magma bodies. (author)

  16. GEOTHERMAL GREENHOUSING IN TURKEY

    Directory of Open Access Journals (Sweden)

    Sedat Karaman

    2016-07-01

    Full Text Available Use of renewable energy resources should be brought forward to reduce heating costs of greenhouses and to minimize the use of ever-depleting fossil fuels. Geothermal energy not only provides the heat required throughout plant growth, but also allow a year-long production. Geothermal resources with several other benefits therefore play significant role in agricultural activities. With regard to geothermal potential and implementation, Turkey has the 7th place in the world and the 1st place in Europe. Majority of country geothermal resources is used in greenhouse heating. The size of geothermal greenhouses increased 5 folds during the last decade and reached to 2500 decare. In this study, current status of geothermal greenhousing of Turkey was presented; problems and possible solutions were discussed.

  17. The geothermal power organization

    Energy Technology Data Exchange (ETDEWEB)

    Scholl, K.L. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-31

    The Geothermal Power Organization is an industry-led advisory group organized to advance the state-of-the-art in geothermal energy conversion technologies. Its goal is to generate electricity from geothermal fluids in the most cost-effective, safe, and environmentally benign manner possible. The group achieves this goal by determining the Member`s interest in potential solutions to technological problems, advising the research and development community of the needs of the geothermal energy conversion industry, and communicating research and development results among its Members. With the creation and adoption of a new charter, the Geothermal Power Organization will now assist the industry in pursuing cost-shared research and development projects with the DOE`s Office of Geothermal Technologies.

  18. 17th Symposium of NEDO projects. Geothermal subcommittee; Chinetsu bunkakai. Dai 17 kai jigyo hokokukai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    Described herein are the reports presented to the geothermal subcommittee. The NEDO's Geothermal Research Department is developing the technologies for accurately predicting the reservoir changes in the future by the geothermal development promotion investigations for distributed conditions of geothermal resources and related environmental impacts, and also by clarifying the hydrogic characteristics of the fracture systems which form the reservoirs. The department is also implementing the projects for investigating/ researching possibilities of resources distribution conditions and utilization for eventual commercialization of the deep underground geothermal resources, and also investigating utilization of small- to medium-sized geothermal binary power generation systems for effective utilization of unutilized geothermal energy. The geothermal technology development group is developing the technologies for the binary cycle power generation plants which effectively utilize unutilized medium- to high-temperature geothermal water for power generation, and also the technologies for collecting conditions at the bottom of a geothermal well being excavated in real time to improve efficiency and precision of the excavation. The other technologies being developed include those for excavation and production essential for development of power generation systems using high-temperature rocks and deep underground geothermal resources, the former being expected to contribute to expanded utilization of geothermal resources and the latter to increased geothermal power generation capacity. (NEDO)

  19. 17th Symposium of NEDO projects. Geothermal subcommittee; Chinetsu bunkakai. Dai 17 kai jigyo hokokukai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    Described herein are the reports presented to the geothermal subcommittee. The NEDO's Geothermal Research Department is developing the technologies for accurately predicting the reservoir changes in the future by the geothermal development promotion investigations for distributed conditions of geothermal resources and related environmental impacts, and also by clarifying the hydrogic characteristics of the fracture systems which form the reservoirs. The department is also implementing the projects for investigating/ researching possibilities of resources distribution conditions and utilization for eventual commercialization of the deep underground geothermal resources, and also investigating utilization of small- to medium-sized geothermal binary power generation systems for effective utilization of unutilized geothermal energy. The geothermal technology development group is developing the technologies for the binary cycle power generation plants which effectively utilize unutilized medium- to high-temperature geothermal water for power generation, and also the technologies for collecting conditions at the bottom of a geothermal well being excavated in real time to improve efficiency and precision of the excavation. The other technologies being developed include those for excavation and production essential for development of power generation systems using high-temperature rocks and deep underground geothermal resources, the former being expected to contribute to expanded utilization of geothermal resources and the latter to increased geothermal power generation capacity. (NEDO)

  20. Geothermal Today - 1999

    Energy Technology Data Exchange (ETDEWEB)

    None

    2000-05-01

    U.S. Department of Energy 1999 Geothermal Energy Program Highlights The Hot Facts Getting into Hot Water Turning Waste water into Clean Energy Producing Even Cleaner Power Drilling Faster and Cheaper Program in Review 1999: The Year in Review JanuaryCal Energy announced sale of Coso geothermal power plants at China Lake, California, to Caithness Energy, for $277 million. U.S. Export-Import Bank completed a $50 million refinancing of the Leyte Geothermal Optimization Project in the Philippines. F

  1. Success in geothermal development

    International Nuclear Information System (INIS)

    Stefansson, V.

    1992-01-01

    Success in geothermal development can be defined as the ability to produce geothermal energy at compatible energy prices to other energy sources. Drilling comprises usually the largest cost in geothermal development, and the results of drilling is largely influencing the final price of geothermal energy. For 20 geothermal fields with operating power plants, the ratio between installed capacity and the total number of well in the field is 1.9 MWe/well. The drilling history in 30 geothermal fields are analyzed by plotting the average cumulative well outputs as function of the number of wells drilled in the field. The range of the average well output is 1-10 MWe/well with the mean value 4.2 MWe/well for the 30 geothermal fields studied. A leaning curve is defined as the number of wells drilled in each field before the average output per well reaches a fairly constant value, which is characteristic for the geothermal reservoir. The range for this learning time is 4-36 wells and the average is 13 wells. In general, the average well output in a given field is fairly constant after some 10-20 wells has been drilled in the field. The asymptotic average well output is considered to be a reservoir parameter when it is normalized to the average drilling depth. In average, this reservoir parameter can be expressed as 3.3 MWe per drilled km for the 30 geothermal fields studied. The lifetime of the resource or the depletion time of the geothermal reservoir should also be considered as a parameter influencing the success of geothermal development. Stepwise development, where the reservoir response to the utilization for the first step is used to determine the timing of the installment of the next step, is considered to be an appropriate method to minimize the risk for over investment in a geothermal field

  2. Effect of heat loss in a geothermal reservoir

    NARCIS (Netherlands)

    Ganguly, Sayantan; Tan, Lippong; Date, Abhijit; Mohan Kumar, Mandalagiri Subbarayappa

    This paper reports a three-dimensional (3D) numerical study to determine the effect of heat loss on the transient heat transport and temperature distribution in a geothermal reservoir. The operation of a geothermal power plant, which is essentially an injection-production process, involves

  3. Study theorizes use of geothermal sources for energy in refineries

    NARCIS (Netherlands)

    Golombok, M.; Beintema, K.

    2008-01-01

    Geothermal sources for direct heating can theoretically serve as an alternative source of high-temperature heat in processing plants. Cutting CO2 emissions from a refinery requires reducing the amount of fuel burned. Heat obtained from geothermal energy is more efficiently used for directly powering

  4. Geothermal direct-heat utilization assistance. Quarterly project progress report, April--June 1993

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.

    1993-06-01

    Technical assistance was provided to 60 requests from 19 states. R&D progress is reported on: evaluation of lineshaft turbine pump problems, geothermal district heating marketing strategy, and greenhouse peaking analysis. Two presentations and one tour were conducted, and three technical papers were prepared. The Geothermal Progress Monitor reported: USGS Forum on Mineral Resources, Renewable Energy Tax Credits Not Working as Congress Intended, Geothermal Industry Tells House Panel, Newberry Pilot Project, and Low-Temperature Geothermal Resources in Nevada.

  5. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  6. Geothermal Energy Program overview

    International Nuclear Information System (INIS)

    1991-12-01

    The mission of the Geothermal Energy Program is to develop the science and technology necessary for tapping our nation's tremendous heat energy sources contained with the Earth. Geothermal energy is a domestic energy source that can produce clean, reliable, cost- effective heat and electricity for our nation's energy needs. Geothermal energy -- the heat of the Earth -- is one of our nation's most abundant energy resources. In fact, geothermal energy represents nearly 40% of the total US energy resource base and already provides an important contribution to our nation's energy needs. Geothermal energy systems can provide clean, reliable, cost-effective energy for our nation's industries, businesses, and homes in the form of heat and electricity. The US Department of Energy's (DOE) Geothermal Energy Program sponsors research aimed at developing the science and technology necessary for utilizing this resource more fully. Geothermal energy originates from the Earth's interior. The hottest fluids and rocks at accessible depths are associated with recent volcanic activity in the western states. In some places, heat comes to the surface as natural hot water or steam, which have been used since prehistoric times for cooking and bathing. Today, wells convey the heat from deep in the Earth to electric generators, factories, farms, and homes. The competitiveness of power generation with lower quality hydrothermal fluids, geopressured brines, hot dry rock, and magma ( the four types of geothermal energy) still depends on the technical advancements sought by DOE's Geothermal Energy Program

  7. City of El Centro geothermal energy utility core field experiment. Final report, February 16, 1979-November 30, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Province, S.G.; Sherwood, P.B.

    1984-11-01

    The City of El Centro was awarded a contract in late 1978 to cost share the development of a low to moderate temperature geothermal resource in the City. The resource would be utilized to heat, cool and provide hot water to the nearby Community Center. In December 1981, Thermal 1 (injector) was drilled to 3970 feet. In January 1982, Thermal 2 (producer) was drilled to 8510 feet. Before testing began, fill migrated into both wells. Both wells were cleaned out. A pump was installed in the producer, but migration of fill again into the injector precluded injection of produced fluid. A short term production test was undertaken and results analyzed. Based upon the analysis, DOE decided that the well was not useful for commercial production due to a low flow rate, the potential problems of continued sanding and gasing, and the requirement to lower the pump setting depth and the associated costs of pumping. There was no commercial user found to take over the wells. Therefore, the wells were plugged and abandoned. The site was restored to its original condition.

  8. Geothermal exploration

    International Nuclear Information System (INIS)

    Hardison, J.E.

    1975-01-01

    A uranium prospecting system based on the determination of temperature anomalies in the earth's crust is described. The earth heat flux is measured at preselected points in shallow boreholes in order to detect heat given off as a result of radioactive decay. Localized anomalies are indicative of concentrations of radioactive materials

  9. Detecting geothermal anomalies and evaluating LST geothermal component by combining thermal remote sensing time series and land surface model data

    NARCIS (Netherlands)

    Romaguera, M.; Vaughan, R. G.; Ettema, J.; Izquierdo-Verdiguier, E.; Hecker, C. A.; van der Meer, F. D.

    This paper explores for the first time the possibilities to use two land surface temperature (LST) time series of different origins (geostationary Meteosat Second Generation satellite data and Noah land surface modelling, LSM), to detect geothermal anomalies and extract the geothermal component of

  10. Detecting geothermal anomalies and evaluating LST geothermal component by combining thermal remote sensing time series and land surface model data

    NARCIS (Netherlands)

    Romaguera, M.; Vaughan, R. G.; Ettema, J.; Izquierdo-Verdiguier, E.; Hecker, C. A.; van der Meer, F. D.

    2017-01-01

    This paper explores for the first time the possibilities to use two land surface temperature (LST) time series of different origins (geostationary Meteosat Second Generation satellite data and Noah land surface modelling, LSM), to detect geothermal anomalies and extract the geothermal component of

  11. Geological model of supercritical geothermal reservoir related to subduction system

    Science.gov (United States)

    Tsuchiya, Noriyoshi

    2017-04-01

    Following the Great East Japan Earthquake and the accident at the Fukushima Daiichi Nuclear power station on 3.11 (11th March) 2011, geothermal energy came to be considered one of the most promising sources of renewable energy for the future in Japan. The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. Supercritical geothermal resources could be evaluated in terms of present volcanic activities, thermal structure, dimension of hydrothermal circulation, properties of fracture system, depth of heat source, depth of brittle factures zone, dimension of geothermal reservoir. On the basis of the GIS, potential of supercritical geothermal resources could be characterized into the following four categories. 1. Promising: surface manifestation d shallow high temperature, 2 Probability: high geothermal gradient, 3 Possibility: Aseismic zone which indicates an existence of melt, 4 Potential : low velocity zone which indicates magma input. Base on geophysical data for geothermal reservoirs, we have propose adequate tectonic model of development of the supercritical geothermal reservoirs. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550

  12. Inverse geothermal modelling applied to Danish sedimentary basins

    DEFF Research Database (Denmark)

    Poulsen, Soren E.; Balling, Niels; Bording, Thue S.

    2017-01-01

    . The numerical model was utilized for predicting and contouring temperatures at 2000 and 3000 m depths and for two main geothermal reservoir units, the Gassum (Lower Jurassic-Upper Triassic) and Bunter/Skagerrak (Triassic) reservoirs, both currently utilized for geothermal energy production. Temperature...... gradients to depths of 2000-3000 m are generally around 25-30. degrees C km(-1), locally up to about 35. degrees C km(-1). Large regions have geothermal reservoirs with characteristic temperatures ranging from ca. 40-50. degrees C, at 1000-1500 m depth, to ca. 80-110. degrees C, at 2500-3500 m, however...

  13. Geothermal investigations in West Virginia

    Energy Technology Data Exchange (ETDEWEB)

    Hendry, R.; Hilfiker, K.; Hodge, D.; Morgan, P.; Swanberg, C.; Shannon, S.S. Jr.

    1982-11-01

    Deep sedimentary basins and warm-spring systems in West Virginia are potential geothermal resources. A temperature gradient map based on 800 bottom-hole temperatures for West Virginia shows that variations of temperature gradient trend northeasterly, parallel to regional structure. Highest temperature gradient values of about 28/sup 0/C/km occur in east-central West Virginia, and the lowest gradients (18/sup 0/C/km) are found over the Rome Trough. Results from ground-water geochemistry indicate that the warm waters circulate in very shallow aquifers and are subject to seasonal temperature fluctuations. Silica heat-flow data in West Virginia vary from about 0.89 to 1.4 HFU and generally increase towards the west. Bouguer, magnetic, and temperature gradient profiles suggest that an ancient rift transects the state and is the site of several deep sedimentary basins.

  14. Geothermal Today: 2003 Geothermal Technologies Program Highlights (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    2004-05-01

    This outreach publication highlights milestones and accomplishments of the DOE Geothermal Technologies Program for 2003. Included in this publication are discussions of geothermal fundamentals, enhanced geothermal systems, direct-use applications, geothermal potential in Idaho, coating technology, energy conversion R&D, and the GeoPowering the West initiative.

  15. Great Western Malting Company geothermal project, Pocatello, Idaho. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, N.T.; McGeen, M.A.; Corlett, D.F.; Urmston, R.

    1981-12-23

    The Great Western Malting Company recently constructed a barley malting facility in Pocatello, Idaho, designed to produce 6.0 million bushels per year of brewing malt. This facility uses natural gas to supply the energy for germination and kilning processes. The escalating cost of natural gas has prompted the company to look at alternate and more economical sources of energy. Trans Energy Systems has investigated the viabiity of using geothermal energy at the new barley processing plant. Preliminary investigations show that a geothermal resource probably exists, and payback on the installation of a system to utilize the resource will occur in under 2 years. The Great Western Malting plant site has geological characteristics which are similar to areas where productive geothermal wells have been established. Geological investigations indicate that resource water temperatures will be in the 150 to 200/sup 0/F range. Geothermal energy of this quality will supply 30 to 98% of the heating requirements currently supplied by natural gas for this malting plant. Trans Energy Systems has analyzed several systems of utilizing the geothermal resource at the Great Western barley malting facility. These systems included: direct use of geothermal water; geothermal energy heating process water through an intermediary heat exchanger; coal or gas boosted geothermal systems; and heat pump boosted geothermal system. The analysis examined the steps that are required to process the grain.

  16. The USGS national geothermal resource assessment: An update

    Science.gov (United States)

    Williams, C.F.; Reed, M.J.; Galanis, S.P.; DeAngelo, J.

    2007-01-01

    The U. S. Geological Survey (USGS) is working with the Department of Energy's (DOE) Geothermal Technologies Program and other geothermal organizations on a three-year effort to produce an updated assessment of available geothermal resources. The new assessment will introduce significant changes in the models for geothermal energy recovery factors, estimates of reservoir volumes, and limits to temperatures and depths for electric power production. It will also include the potential impact of evolving Enhanced Geothermal Systems (EGS) technology. An important focus in the assessment project is on the development of geothermal resource models consistent with the production histories and observed characteristics of exploited geothermal fields. New models for the recovery of heat from heterogeneous, fractured reservoirs provide a physically realistic basis for evaluating the production potential of both natural geothermal reservoirs and reservoirs that may be created through the application of EGS technology. Project investigators have also made substantial progress studying geothermal systems and the factors responsible for their formation through studies in the Great Basin-Modoc Plateau region, Coso, Long Valley, the Imperial Valley and central Alaska, Project personnel are also entering the supporting data and resulting analyses into geospatial databases that will be produced as part of the resource assessment.

  17. Diagenetic effect on permeabilities of geothermal sandstone reservoirs

    DEFF Research Database (Denmark)

    Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

    The Danish subsurface contains abundant sedimentary deposits, which can be utilized for geothermal heating. The Upper Triassic – Lower Jurassic continental-marine sandstones of the Gassum Formation has been utilised as a geothermal reservoir for the Thisted Geothermal Plant since 1984 extracting...... and permeability is caused by increased diagenetic changes of the sandstones due to increased burial depth and temperatures. Therefore, the highest water temperatures typically correspond with the lowest porosities and permeabilities. Especially the permeability is crucial for the performance of the geothermal......-line fractures. Continuous thin chlorite coatings results in less porosity- and permeability-reduction with burial than the general reduction with burial, unless carbonate cemented. Therefore, localities of sandstones characterized by these continuous chlorite coatings may represent fine geothermal reservoirs...

  18. Geothermal Financing Workbook

    Energy Technology Data Exchange (ETDEWEB)

    Battocletti, E.C.

    1998-02-01

    This report was prepared to help small firm search for financing for geothermal energy projects. There are various financial and economics formulas. Costs of some small overseas geothermal power projects are shown. There is much discussion of possible sources of financing, especially for overseas projects. (DJE-2005)

  19. Prospects of geothermal energy

    International Nuclear Information System (INIS)

    Manzella, A.; Bianchi, A.

    2008-01-01

    Geothermal energy has great potential as a renewable energy with low environmental impact, the use of heat pumps is becoming established in Italy but the national contributions are still modest when compared to other nations. Mature technologies could double the installed geothermal power in Italy at 2020. [it

  20. Possibilities for electricity production from geothermal energy in Slovenia in the next decade

    Directory of Open Access Journals (Sweden)

    Dušan Rajver

    2012-06-01

    Full Text Available This article is intended to raise awareness of the public, with the aim that anyone can judge reality and accuracyof records that appear in the media on the exploitation of geothermal energy. It provides a comprehensive overviewof geothermal systems, potential of hydrothermal and enhanced geothermal systems, of mechanisms and characteristicsof middle and high enthalpy geothermal resources. It also deals with a mode of their conversion into electricity.Featured are the main factors affecting the decision on effectiveness of conversion of geothermal energy intoelectricity. Given are the review of the research necessary to establish the geothermal potential and assessment oftechnological and economic possibilities of installing geothermal power plants in Slovenia. The paper also describesthe state of knowledge of middle- and high temperature geothermal resources in Slovenia with initial conditions forconstructing geothermal power plants. In addition, we present theoretical calculations of the conversion efficiencyof geothermal energy into electricity with conventional turbines and present some problems for the exploitationof geothermal energy, which are associated with additional costs and further reduce the efficiency of investment.Described are the characteristics and performance of binary geothermal power plants and foreign experience inobtaining electricity from the EGS (Enhanced Geothermal System. We also address the overlapping of the oil andgas industry with the operation of the EGS and the possibility of exploiting oil and gas wells for producing thegeothermal electricity.

  1. Mental health in low-to-moderate risk preterm, low birth weight, and small for gestational age children at 4 to 5 years: the role of early maternal parenting.

    Science.gov (United States)

    Westrupp, Elizabeth M; Mensah, Fiona K; Giallo, Rebecca; Cooklin, Amanda; Nicholson, Jan M

    2012-03-01

    The majority of children born preterm, with low birth weight, or small for gestational age are born with low-to-moderate risk (LTM), yet most research focuses on the high-risk group. Little is known about whether children with LTM perinatal risk are at greater risk for mental health problems, or what the role of early maternal parenting is in determining these outcomes. Longitudinal data were from a large nationally representative Australian cohort of 5,000 children, aged 0 to 1, 2 to 3, and 4 to 5 years of age. Participants were 354 children with LTM perinatal risk born at 33 to 36 weeks, with birth weight 1,501 to 2,499 grams, or born between the first and 10th percentiles for gestational age; and 2,461 children in the normal birth weight, term comparison group. Child mental health was measured by mother-report on the Strengths and Difficulties Questionnaire (SDQ). Parenting irritability, warmth, self-efficacy, maternal separation anxiety, and overprotective parenting were measured when children were 0 to 1 and 2 to 3 years of age. Parents in the LTM perinatal risk group were more likely to experience parenting difficulties on one of eight parenting measures (irritable parenting at age 0-1 year) when adjusting for socio-demographic differences (odds ratio = 1.43; 95% confidence interval = 1.05, 1.95, p parenting, pathway to psychological risk in children born with LTM perinatal risk. Copyright © 2012 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  2. Dual antiplatelet therapy versus oral anticoagulation plus dual antiplatelet therapy in patients with atrial fibrillation and low-to-moderate thromboembolic risk undergoing coronary stenting: design of the MUSICA-2 randomized trial.

    Science.gov (United States)

    Sambola, Antonia; Montoro, J Bruno; Del Blanco, Bruno García; Llavero, Nadia; Barrabés, José A; Alfonso, Fernando; Bueno, Héctor; Cequier, Angel; Serra, Antonio; Zueco, Javier; Sabaté, Manel; Rodríguez-Leor, Oriol; García-Dorado, David

    2013-10-01

    Oral anticoagulation (OAC) is the recommended therapy for patients with atrial fibrillation (AF) because it reduces the risk of stroke and other thromboembolic events. Dual antiplatelet therapy (DAPT) is required after percutaneous coronary intervention and stenting (PCI-S). In patients with AF requiring PCI-S, the association of DAPT and OAC carries an increased risk of bleeding, whereas OAC therapy or DAPT alone may not protect against the risk of developing new ischemic or thromboembolic events. The MUSICA-2 study will test the hypothesis that DAPT compared with triple therapy (TT) in patients with nonvalvular AF at low-to-moderate risk of stroke (CHADS2 score ≤2) after PCI-S reduces the risk of bleeding and is not inferior to TT for preventing thromboembolic complications. The MUSICA-2 is a multicenter, open-label randomized trial that will compare TT with DAPT in patients with AF and CHADS2 score ≤2 undergoing PCI-S. The primary end point is the incidence of stroke or any systemic embolism or major adverse cardiac events: death, myocardial infarction, stent thrombosis, or target vessel revascularization at 1 year of PCI-S. The secondary end point is the combination of any cardiovascular event with major or minor bleeding at 1 year of PCI-S. The calculated sample size is 304 patients. The MUSICA-2 will attempt to determine the most effective and safe treatment in patients with nonvalvular AF and CHADS2 score ≤2 after PCI-S. Restricting TT for AF patients at high risk for stroke may reduce the incidence of bleeding without increasing the risk of thromboembolic complications. © 2013.

  3. Synthesis of mordenite in geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Konoya, M [Geological Survey of Hokkaido, Japan

    1970-03-01

    A study of the possible synthesis of mordenite in geothermal wells was conducted. In 1966 as part of a series of exploratory geothermal investigations, a 500 m well was drilled which had a temperature at 250 m of 120/sup 0/C. The well has constant temperature and constant pressure and has been used to study alteration. Specimens which were placed in the well were tested for mordenite. Mordenite was synthesized when Benki clay and a 10% KOH solution were placed in a Teflon tube at 250 m (120/sup 0/C and 22.3 kg/cm/sup 2/) for three months. No mordenite was synthesized when obsidian powder was used. These results indicate the possibility of synthesis of zeolite and clay minerals in geothermal wells. Two figures and four tables are provided.

  4. Renewability of geothermal resources

    Energy Technology Data Exchange (ETDEWEB)

    O' Sullivan, Michael; Yeh, Angus [Department of Engineering Science, University of Auckland, Auckland (New Zealand); Mannington, Warren [Contact Energy Limited, Taupo (New Zealand)

    2010-12-15

    In almost all geothermal projects worldwide, the rate of extraction of heat energy exceeds the pre-exploitation rate of heat flow from depth. For example, current production of geothermal heat from the Wairakei-Tauhara system exceeds the natural recharge of heat by a factor of 4.75. Thus, the current rate of heat extraction from Wairakei-Tauhara is not sustainable on a continuous basis, and the same statement applies to most other geothermal projects. Nevertheless, geothermal energy resources are renewable in the long-term because they would fully recover to their pre-exploitation state after an extended shut-down period. The present paper considers the general issue of the renewability of geothermal resources and uses computer modeling to investigate the renewability of the Wairakei-Tauhara system. In particular, modeling is used to simulate the recovery of Wairakei-Tauhara after it is shut down in 2053 after a hundred years of production. (author)

  5. Reinjection of geothermal water-imperative of geothermal system Geoterma - Kochani

    International Nuclear Information System (INIS)

    Naunov, Jordan

    2007-01-01

    Geothermal locality 'Podlog-Banja' - Kochani, Republic of Macedonia, represent one of the more significant aquifers of geothermal water, not only in local frames but also in world scale, especially if we have in mind the possible capacity of exploitation of 300 l, with average temperature of 75° C. Many years of exploitation was escorted with constant irreversible drop down of piezo metric level of underground waters and because of this reason, there was a necessary of installation of reinjection system of used geothermal water, especially for two factors: Keeping of balance conditions in the underground from one side and reduction of thermal pollution to the environment especially from energetic and ecological aspect. In this written effort beside the basic information for geothermal system 'Geoterma' will be present all significant phases and elements of the system for reinjection, it's exploration, implementation, construction and of course the effects from the same one. (Author)

  6. Geothermal Program Review XI: proceedings. Geothermal Energy - The Environmental Responsible Energy Technology for the Nineties

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    These proceedings contain papers pertaining to current research and development of geothermal energy in the USA. The seven sections of the document are: Overview, The Geysers, Exploration and Reservoir Characterization, Drilling, Energy Conversion, Advanced Systems, and Potpourri. The Overview presents current DOE energy policy and industry perspectives. Reservoir studies, injection, and seismic monitoring are reported for the geysers geothermal field. Aspects of geology, geochemistry and models of geothermal exploration are described. The Drilling section contains information on lost circulation, memory logging tools, and slim-hole drilling. Topics considered in energy conversion are efforts at NREL, condensation on turbines and geothermal materials. Advanced Systems include hot dry rock studies and Fenton Hill flow testing. The Potpourri section concludes the proceedings with reports on low-temperature resources, market analysis, brines, waste treatment biotechnology, and Bonneville Power Administration activities. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  7. Geothermal country update of Japan

    International Nuclear Information System (INIS)

    Higo, M.

    1990-01-01

    This paper reports on the status of geothermal energy in Japan. Topics covered include: present and planned production of electricity, present utilization of geothermal energy for direct heat, information about geothermal localities, and wells drilled for electrical utilization of geothermal resources to January 1, 1990

  8. Geothermal energy: a brief assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lunis, B.C.; Blackett, R.; Foley, D. (eds.)

    1982-07-01

    This document includes discussions about geothermal energy, its applications, and how it is found and developed. It identifies known geothermal resources located in Western's power marketing area, and covers the use of geothermal energy for both electric power generation and direct applications. Economic, institutional, environmental, and other factors are discussed, and the benefits of the geothermal energy resource are described.

  9. Klamath Falls geothermal field, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.; Culver, G.; Lund, J.W.

    1989-09-01

    Klamath Falls, Oregon, is located in a Known Geothermal Resource Area which has been used by residents, principally to obtain geothermal fluids for space heating, at least since the turn of the century. Over 500 shallow-depth wells ranging from 90 to 2,000 ft (27 to 610 m) in depth are used to heat (35 MWt) over 600 structures. This utilization includes the heating of homes, apartments, schools, commercial buildings, hospital, county jail, YMCA, and swimming pools by individual wells and three district heating systems. Geothermal well temperatures range from 100 to 230{degree}F (38 to 110{degree}C) and the most common practice is to use downhole heat exchangers with city water as the circulating fluid. Larger facilities and district heating systems use lineshaft vertical turbine pumps and plate heat exchangers. Well water chemistry indicates approximately 800 ppM dissolved solids, with sodium sulfate having the highest concentration. Some scaling and corrosion does occur on the downhole heat exchangers (black iron pipe) and on heating systems where the geo-fluid is used directly. 73 refs., 49 figs., 6 tabs.

  10. Estimate of Hot Dry Rock Geothermal Resource in Daqing Oilfield, Northeast China

    OpenAIRE

    Guangzheng Jiang; Yi Wang; Yizuo Shi; Chao Zhang; Xiaoyin Tang; Shengbiao Hu

    2016-01-01

    Development and utilization of deep geothermal resources, especially a hot dry rock (HDR) geothermal resource, is beneficial for both economic and environmental consideration in oilfields. This study used data from multiple sources to assess the geothermal energy resource in the Daqing Oilfield. The temperature logs in boreholes (both shallow water wells and deep boreholes) and the drilling stem test temperature were used to create isothermal maps in depths. Upon the temperature field and the...

  11. Thermodynamics of geothermal fluids

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, P.S.Z.

    1981-03-01

    A model to predict the thermodynamic properties of geothermal brines, based on a minimum amount of experimental data on a few key systems, is tested. Volumetric properties of aqueous sodium chloride, taken from the literature, are represented by a parametric equation over the range 0 to 300{sup 0}C and 1 bar to 1 kbar. Density measurements at 20 bar needed to complete the volumetric description also are presented. The pressure dependence of activity and thermal properties, derived from the volumetric equation, can be used to complete an equation of state for sodium chloride solutions. A flow calorimeter, used to obtain heat capacity data at high temperatures and pressures, is described. Heat capacity measurements, from 30 to 200{sup 0}C and 1 bar to 200 bar, are used to derive values for the activity coefficient and other thermodynamic properties of sodium sulfate solutions as a function of temperature. Literature data on the solubility of gypsum in mixed electrolyte solutions have been used to evaluate model parameters for calculating gypsum solubility in seawater and natural brines. Predictions of strontium and barium sulfate solubility in seawater also are given.

  12. Quantifying the undiscovered geothermal resources of the United States

    Science.gov (United States)

    Williams, Colin F.; Reed, Marshall J.; DeAngelo, Jacob; Galanis, S. Peter

    2009-01-01

    In 2008, the U.S. Geological Survey (USGS) released summary results of an assessment of the electric power production potential from the moderate- and high-temperature geothermal resources of the United States (Williams et al., 2008a; USGS Fact Sheet 2008-3082; http://pubs.usgs.gov/fs/2008/3082). In the assessment, the estimated mean power production potential from undiscovered geothermal resources is 30,033 Megawatts-electric (MWe), more than three times the estimated mean potential from identified geothermal systems: 9057 MWe. The presence of significant undiscovered geothermal resources has major implications for future exploration and development activities by both the government and private industry. Previous reports summarize the results of techniques applied by the USGS and others to map the spatial distribution of undiscovered resources. This paper describes the approach applied in developing estimates of the magnitude of the undiscovered geothermal resource, as well as the manner in which that resource is likely to be distributed among geothermal systems of varying volume and temperature. A number of key issues constrain the overall estimate. One is the degree to which characteristics of the undiscovered resources correspond to those observed among identified geothermal systems. Another is the evaluation of exploration history, including both the spatial distribution of geothermal exploration activities relative to the postulated spatial distribution of undiscovered resources and the probability of successful discoveries from the application of standard geothermal exploration techniques. Also significant are the physical, chemical, and geological constraints on the formation and longevity of geothermal systems. Important observations from this study include the following. (1) Some of the largest identified geothermal systems, such as The Geysers vapor-dominated system in northern California and the diverse geothermal manifestations found in Yellowstone

  13. Water Intensity of Electricity from Geothermal Resources

    Science.gov (United States)

    Mishra, G. S.; Glassley, W. E.

    2010-12-01

    BACKGROUND Electricity from geothermal resources could play a significant role in the United States over the next few decades; a 2006 study by MIT expects a capacity of 100GWe by 2050 as feasible; approximately 10% of total electricity generating capacity up from less than 1% today. However, there is limited research on the water requirements and impacts of generating electricity from geothermal resources - conventional as well as enhanced. To the best of our knowledge, there is no baseline exists for water requirements of geothermal electricity. Water is primarily required for cooling and dissipation of waste heat in the power plants, and to account for fluid losses during heat mining of enhanced geothermal resources. MODEL DESCRIPTION We have developed a model to assess and characterize water requirements of electricity from hydrothermal resources and enhanced geothermal resources (EGS). Our model also considers a host of factors that influence cooling water requirements ; these include the temperature and chemical composition of geothermal resource; installed power generation technology - flash, organic rankine cycle and the various configurations of these technologies; cooling technologies including air cooled condensers, wet recirculating cooling, and hybrid cooling; and finally water treatment and recycling installations. We expect to identify critical factors and technologies. Requirements for freshwater, degraded water and geothermal fluid are separately estimated. METHODOLOGY We have adopted a lifecycle analysis perspective that estimates water consumption at the goethermal field and power plant, and accounts for transmission and distribution losses before reaching the end user. Our model depends upon an extensive literature review to determine various relationships necessary to determine water usage - for example relationship between thermal efficiency and temperature of a binary power plant, or differences in efficiency between various ORC configurations

  14. Understanding the circulation of geothermal waters in the Tibetan Plateau using oxygen and hydrogen stable isotopes

    International Nuclear Information System (INIS)

    Tan, Hongbing; Zhang, Yanfei; Zhang, Wenjie; Kong, Na; Zhang, Qing; Huang, Jingzhong

    2014-01-01

    Highlights: • Unique geothermal resources in Tibetan Plateau were discussed. • Isotopes were used to trace circulation of geothermal water. • Magmatic water mixing dominates geothermal water evolution. - Abstract: With the uplift of the Tibetan Plateau, many of the world’s rarest and most unique geothermal fields have been developed. This study aims to systematically analyze the characteristics of the hydrogen and oxygen isotopic data of geothermal, river, and lake waters to understand the circulation of groundwater and to uncover the mechanism of geothermal formation in the Tibetan Plateau. Field observations and isotopic data show that geothermal water has higher temperatures and hydraulic pressures, as well as more depleted D and 18 O isotopic compositions than river and lake waters. Thus, neither lakes nor those larger river waters are the recharge source of geothermal water. Snow-melt water in high mountains can vertically infiltrate and deeply circulate along some stretching tensile active tectonic belts or sutures and recharge geothermal water. After deep circulation, cold surface water evolves into high-temperature thermal water and is then discharged as springs at the surface again in a low area, under high water-head difference and cold–hot water density difference. Therefore, the large-scale, high-temperature, high-hydraulic-pressure geothermal systems in the Tibetan Plateau are developed and maintained by rapid groundwater circulation and the heat source of upwelled residual magmatic water. Inevitably, the amount of geothermal water will increase if global warming accelerates the melting of glaciers in high mountains

  15. Outline of multipurpose utilization of geothermal resources in China

    Energy Technology Data Exchange (ETDEWEB)

    Huang, S.Y.; Wang, J.Y.; Wang, J.; Huang, G.S.

    1980-09-01

    China is rich in geothermal resources. The lower temperature limit of geothermal waters in China is defined as 25/sup 0/C. The thermal waters are categorized into three groups: low (25/sup 0/ to 60/sup 0/C), medium (60/sup 0/ to 100/sup 0/C) and high (> 100/sup 0/C) temperature thermal water. Xizang (Tibet), Taiwan and Yunnan are the most promising regions for the development of high temperature geothermal energy. Medium-low temperature water is more efficient for direct use. Since 1977, six experimental geothermal power stations have been set up throughout the country. In Beijing (Peking), Tianjin and other places thermal water has been used for space heating, industrial processing, agriculture, horticulture, and therapeutic sanatoriums, etc.

  16. Development of Genetic Occurrence Models for Geothermal Prospecting

    Science.gov (United States)

    Walker, J. D.; Sabin, A.; Unruh, J.; Monastero, F. C.; Combs, J.

    2007-12-01

    , including high heat flow, anomalous temperature water wells, high-temperature indications from aqueous geothermometry and geochemistry, Pliocene or younger ages from low-temperature thermochronometers, as well as more obvious factors such as geysers and fumaroles (which by definition will be missing for blind resources). Our occurrence-model strategy inverts the current approach that relies first on obvious evidence of geothermal activity. We evaluated our approach by retrospectively applying the protocol to the characteristics of producing geothermal fields, and in all cases, known resource areas fit the parameters identified from a genetic perspective.

  17. Global geothermal energy scenario

    International Nuclear Information System (INIS)

    Singh, S.K.; Singh, A.; Pandey, G.N.

    1993-01-01

    To resolve the energy crisis efforts have been made in exploring and utilizing nonconventional energy resources since last few decades. Geothermal energy is one such energy resource. Fossil fuels are the earth's energy capital like money deposited in bank years ago. The energy to build this energy came mainly from the sun. Steam geysers and hot water springs are other manifestations of geothermal energy. Most of the 17 countries that today harness geothermal energy have simply tapped such resources where they occur. (author). 8 refs., 4 tabs., 1 fig

  18. Worldwide installed geothermal power

    International Nuclear Information System (INIS)

    Laplaige, P.

    1995-01-01

    Worldwide electric energy production data are easy to compile, according to the informations given by individual countries. On the contrary, thermal applications of geothermics are difficult to quantify due to the variety of applications and the number of countries concerned. Exhaustive informations sometimes cannot be obtained from huge countries (China, Russia..) because of data centralization problems or not exploitable data transmission. Therefore, installed power data for geothermal heat production are given for 26 countries over the 57 that have answered the International Geothermal Association questionnaire. (J.S.). 1 fig., 2 tabs., 1 photo

  19. Geothermal electricity generation

    International Nuclear Information System (INIS)

    Eliasson, E.T.

    1991-01-01

    Geothermal conversion, as discussed here, is the conversion of the heat bound within the topmost three kilometres of the upper crust of the earth into useful energy, principally electricity. The characteristics of a geothermal reservoir and its individual technical features are highly site-specific. Applications therefore must be designed to match the specific geothermal reservoir. An estimate of the electric energy potential world-wide made by the Electric Power Research Institute (United States) in 1978 and based on sustaining a continuous 30-year operation is given in the box at the right for comparison purposes only. 8 refs, 5 figs

  20. Navy Geothermal Plan

    Energy Technology Data Exchange (ETDEWEB)

    1984-12-01

    Domestic geothermal resources with the potential for decreasing fossil fuel use and energy cost exist at a significant number of Navy facilities. The Geothermal Plan is part of the Navy Energy R and D Program that will evaluate Navy sites and provide a technical, economic, and environmental base for subsequent resource use. One purpose of the program will be to provide for the transition of R and D funded exploratory efforts into the resource development phase. Individual Navy geothermal site projects are described as well as the organizational structure and Navy decision network. 2 figs.

  1. 2016 Geothermal Technologies Office Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-03-01

    This report highlights project successes and continued efforts in all of our program areas – EGS, Hydrothermal, Low-Temperature, and Systems Analysis – which are flanked by useful tools and resources and links to more information. Such highlights include FORGE and EGS successes, projects reducing geothermal costs and risks, and advancements in technology research and development.

  2. INEL Geothermal Environmental Program. Final environmental report

    Energy Technology Data Exchange (ETDEWEB)

    Thurow, T.L.; Cahn, L.S.

    1982-09-01

    An overview of environmental monitoring programs and research during development of a moderate temperature geothermal resource in the Raft River Valley is presented. One of the major objectives was to develop programs for environmental assessment and protection that could serve as an example for similar types of development. The monitoring studies were designed to establish baseline conditions (predevelopment) of the physical, biological, and human environment. Potential changes were assessed and adverse environmental impacts minimized. No major environmental impacts resulted from development of the Raft River Geothermal Research Facility. The results of the physical, biological, and human environment monitoring programs are summarized.

  3. Development of drilling foams for geothermal applications

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, W.J.; Remont, L.J.; Rehm, W.A.; Chenevert, M.E.

    1980-01-01

    The use of foam drilling fluids in geothermal applications is addressed. A description of foams - what they are, how they are used, their properties, equipment required to use them, the advantages and disadvantages of foams, etc. - is presented. Geothermal applications are discussed. Results of industry interviews presented indicate significant potential for foams, but also indicate significant technical problems to be solved to achieve this potential. Testing procedures and results of tests on representative foams provide a basis for work to develop high-temperature foams.

  4. Fairbanks Geothermal Energy Project Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Karl, Bernie [CHSR,LLC Owner

    2013-05-31

    The primary objective for the Fairbanks Geothermal Energy Project is to provide another source of base-load renewable energy in the Fairbanks North Star Borough (FNSB). To accomplish this, Chena Hot Springs Resort (Chena) drilled a re-injection well to 2700 feet and a production well to 2500 feet. The re-injection well allows a greater flow of water to directly replace the water removed from the warmest fractures in the geothermal reservoir. The new production will provide access to warmer temperature water in greater quantities.

  5. Industrial application of geothermal energy in Southeast Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Batdorf, J.A.; McClain, D.W.; Gross, M.; Simmons, G.M.

    1980-02-01

    Those phosphate related and food processing industries in Southeastern Idaho are identified which require large energy inputs and the potential for direct application of geothermal energy is assessed. The total energy demand is given along with that fractional demand that can be satisfied by a geothermal source of known temperature. The potential for geothermal resource development is analyzed by examining the location of known thermal springs and wells, the location of state and federal geothermal exploration leases, and the location of federal and state oil and gas leasing activity in Southeast Idaho. Information is also presented regarding the location of geothermal, oil, and gas exploration wells in Southeast Idaho. The location of state and federal phosphate mining leases is also presented. This information is presented in table and map formats to show the proximity of exploration and development activities to current food and phosphate processing facilities and phosphate mining activities. (MHR)

  6. Application of the geothermal energy in the industrial processes

    International Nuclear Information System (INIS)

    Popovska-Vasilevska, Sanja

    2001-01-01

    In the worldwide practice, the geothermal energy application, as an alternative energy resource, can be of great importance. This is especially case in the countries where exceptional natural geothermal potential exists. Despite using geothermal energy for both greenhouses heating and balneology, the one can be successfully implemented in the heat requiring industrial processes. This kind of use always provides greater annual heat loading factor, since the industrial processes are not seasonal (or not the greater part of them). The quality of the geothermal resources that are available in Europe, dictates the use within the low-temperature range technological processes. However, these processes are significantly engaged in different groups of processing industries. But, beside this fact the industrial application of geothermal energy is at the beginning in the Europe. (Original)

  7. Federal Geothermal Research Program Update Fiscal Year 1998

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.G.

    1999-05-01

    This report reviews the specific objectives, status, and accomplishments of DOE's Geothermal Research Program for Fiscal Year 1998. The Exploration Technology research area focuses on developing instruments and techniques to discover hidden hydrothermal systems and to expose the deep portions of known systems. The Reservoir Technology research combines laboratory and analytical investigations with equipment development and field testing to establish practical tools for resource development and management for both hydrothermal and hot dry rock reservoirs. The Drilling Technology projects focus on developing improved, economic drilling and completion technology for geothermal wells. The Conversion Technology research focuses on reducing costs and improving binary conversion cycle efficiency, to permit greater use of the more abundant moderate-temperature geothermal resource, and on the development of materials that will improve the operating characteristics of many types of geothermal energy equipment. Direct use research covers the direct use of geothermal energy sources for applications in other than electrical production.

  8. Geothermal energy. Ground source heat pumps

    International Nuclear Information System (INIS)

    2009-01-01

    Geothermal energy can be harnessed in 2 different ways: electricity or heat generation. The combined net electrical geothermal power of the European Union countries reached 719.3 MWe in 2008 (4.8 MW up on 2007) for 868.1 MWe of installed capacity. Gross electrical production contracted slightly in 2008 (down 1% on the 2007 level) and stood at 5809.5 GWh in 2008. Italy has a overwhelming position with a production of 5520.3 GWh. Geothermal heat production concerning aquifers whose temperature is 30-150 C. degrees generally at a depth of 1-3 km is called low- and medium-enthalpy energy. 18 of the 27 EU members use low- and medium-enthalpy energy totaling 2560.0 MWth of installed capacity that yielded 689.2 ktoe in 2008 and 3 countries Hungary, Italy and France totaling 480.3 ktoe. Very low-enthalpy energy concerns the exploitation of shallow geothermal resources using geothermal heat pumps. In 2008, 114452 ground heat pumps were sold in Europe. At the end of 2008, the installed capacity was 8955.4 MWth (16.5% up on 2007 level, it represented 785206 pumps. Over one million ground heat pumps are expected to be operating in 2010 in Europe. (A.C.)

  9. Submarine geothermal resources

    Science.gov (United States)

    Williams, D.L.

    1976-01-01

    Approximately 20% of the earth's heat loss (or 2 ?? 1012 cal/s) is released through 1% of the earth's surface area and takes the form of hydrothermal discharge from young (Pleistocene or younger) rocks adjacent to active seafloor-spreading centers and submarine volcanic areas. This amount is roughly equivalent to man's present gross energy consumption rate. A sub-seafloor geothermal reservoir, to be exploitable under future economic conditions, will have to be hot, porous, permeable, large, shallow, and near an energy-deficient, populated land mass. Furthermore, the energy must be recoverable using technology achievable at a competitive cost and numerous environmental, legal and institutional problems will have to be overcome. The highest-temperature reservoirs should be found adjacent to the zones of the seafloor extension or volcanism that are subject to high sedimentation rates. The relatively impermeable sediments reduce hydrothermal-discharge flow rates, forcing the heat to be either conducted away or released by high-temperature fluids, both of which lead to reservoir temperatures that can exceed 300??C. There is evidence that the oceanic crust is quite permeable and porous and that it was amenable to deep (3-5 km) penetration by seawater at least some time in the early stages of its evolution. Most of the heat escapes far from land, but there are notable exceptions. For example, in parts of the Gulf of California, thermal gradients in the bottom sediments exceed 1??C/m. In the coastal areas of the Gulf of California, where electricity and fresh water are at a premium, this potential resource lies in shallow water (characteristics of these systems before they can be considered a viable resource. Until several of the most promising areas are carefully defined and drilled, the problem will remain unresolved. ?? 1976.

  10. Geothermal Risk Reduction via Geothermal/Solar Hybrid Power Plants. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mines, Greg [Idaho National Lab. (INL), Idaho Falls, ID (United States); Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhu, Guangdong [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-11-01

    There are numerous technical merits associated with a renewable geothermal-solar hybrid plant concept. The performance of air-cooled binary plants is lowest when ambient temperatures are high due to the decrease in air-cooled binary plant performance that occurs when the working fluid condensing temperature, and consequently the turbine exhaust pressure, increases. Electrical power demand is generally at peak levels during periods of elevated ambient temperature and it is therefore especially important to utilities to be able to provide electrical power during these periods. The time periods in which air-cooled binary geothermal power plant performance is lowest generally correspond to periods of high solar insolation. Use of solar heat to increase air-cooled geothermal power plant performance during these periods can improve the correlation between power plant output and utility load curves. While solar energy is a renewable energy source with long term performance that can be accurately characterized, on shorter time scales of hours or days it can be highly intermittent. Concentrating solar power (CSP), aka solar-thermal, plants often incorporate thermal energy storage to ensure continued operation during cloud events or after sunset. Hybridization with a geothermal power plant can eliminate the need for thermal storage due to the constant availability of geothermal heat. In addition to the elimination of the requirement for solar thermal storage, the ability of a geothermal/solar-thermal hybrid plant to share a common power block can reduce capital costs relative to separate, stand-alone geothermal and solar-thermal power plant installations. The common occurrence of long-term geothermal resource productivity decline provides additional motivation to consider the use of hybrid power plants in geothermal power production. Geothermal resource productivity decline is a source of significant risk in geothermal power generation. Many, if not all, geothermal resources

  11. The Parisian basin, birthplace of geothermics

    International Nuclear Information System (INIS)

    Jeanson, E.

    1995-01-01

    The exploitation of low energy geothermics in France is mainly localized in the Parisian Basin. About 40 geothermal plants are established in urbanized areas for heating and sanitary hot water supplies and also for air conditioning. Each plant can supply about 2500 to 5000 lodgings of collective buildings. Excluding drilling costs, urban investments can reach 70% of the total operating cost. Most of the exploitations draw the geothermal fluids from the Dogger reservoir located at a 1500-2000 m depth using double-well technique. Water temperature is about 60 to 85 C and solutes (salts and sulfides) represent 15 to 35 g/l. The deeper Albian and Neocomian drinking water reservoirs are exceptionally used due to their strategic nature. The corrosion problems and the age of the installations are the principal problems of the existing installations but the operating costs remain competitive with other energy sources. (J.S.). 3 figs., 9 photos

  12. First assessment of low- to medium-temperature geothermal reserves in 20 Mexican states; Primera estimacion de las reservas geotermicas de temperatura intermedia a baja en veinte estados de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, Eduardo R.; Torres, Rodolfo J. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: iglesias@iie.org.mx

    2009-07-15

    A first, partial, assessment is included of the low- to medium-temperature geothermal reserves in 20 Mexican States and their aggregate value. The assessment covers about 29.16% of the identified geothermal-surface manifestations in the public database. For reserve assessments, we use the volumetric method, supplemented with Montecarlo simulations and statistics, to quantify inherent uncertainties. Our estimations are presented on a state-by-state basis. We estimate the aggregated reserves of the 20 states as between 7.7 x 1016 and 8.6 x 1016 kJ, with 90% confidence. The most likely reservoir temperatures range between 60-180 degrees Celsius, with a mean of 111 degrees Celsius. Such massive amounts of recoverable energy-and the associated temperatures-are potentially important for the economic development of nearby localities and the nation. [Spanish] En este trabajo se hace una primera estimacion, parcial, de las reservas geotermicas de temperatura intermedia a baja de Mexico. La estimacion incluye 29.16% de las manifestaciones geotermicas identificadas en la base de datos publica utilizada. Para estimar las reservas se utilizo el metodo de volumen, suplementado con simulaciones por el metodo de Montecarlo, con el fin de cuantificar las incertidumbres inherentes. Las estimaciones se presentan estado por estado. Estos resultados indican que las reservas agregadas de los 20 estados considerados estan entre 7.7 x 1016 y 8.6 x 1016 kJ, con 90% de confianza. La distribucion de las temperaturas de yacimiento mas probables varia entre aproximadamente 60 y 180 grados centigrados, con un valor medio de 111 grados centigrados. La enorme magnitud de estas reservas, y sus temperaturas asociadas, son potencialmente importantes para el desarrollo economico de las poblaciones ubicadas en su cercania.

  13. Realizing the geothermal electricity potential—water use and consequences

    Science.gov (United States)

    Shankar Mishra, Gouri; Glassley, William E.; Yeh, Sonia

    2011-07-01

    Electricity from geothermal resources has the potential to supply a significant portion of US baseload electricity. We estimate the water requirements of geothermal electricity and the impact of potential scaling up of such electricity on water demand in various western states with rich geothermal resources but stressed water resources. Freshwater, degraded water, and geothermal fluid requirements are estimated explicitly. In general, geothermal electricity has higher water intensity (l kWh - 1) than thermoelectric or solar thermal electricity. Water intensity decreases with increase in resource enthalpy, and freshwater gets substituted by degraded water at higher resource temperatures. Electricity from enhanced geothermal systems (EGS) could displace 8-100% of thermoelectricity generated in most western states. Such displacement would increase stress on water resources if re-circulating evaporative cooling, the dominant cooling system in the thermoelectric sector, is adopted. Adoption of dry cooling, which accounts for 78% of geothermal capacity today, will limit changes in state-wide freshwater abstraction, but increase degraded water requirements. We suggest a research and development focus to develop advanced energy conversion and cooling technologies that reduce water use without imposing energy and consequent financial penalties. Policies should incentivize the development of higher enthalpy resources, and support identification of non-traditional degraded water sources and optimized siting of geothermal plants.

  14. Realizing the geothermal electricity potential-water use and consequences

    International Nuclear Information System (INIS)

    Mishra, Gouri Shankar; Yeh, Sonia; Glassley, William E

    2011-01-01

    Electricity from geothermal resources has the potential to supply a significant portion of US baseload electricity. We estimate the water requirements of geothermal electricity and the impact of potential scaling up of such electricity on water demand in various western states with rich geothermal resources but stressed water resources. Freshwater, degraded water, and geothermal fluid requirements are estimated explicitly. In general, geothermal electricity has higher water intensity (l kWh -1 ) than thermoelectric or solar thermal electricity. Water intensity decreases with increase in resource enthalpy, and freshwater gets substituted by degraded water at higher resource temperatures. Electricity from enhanced geothermal systems (EGS) could displace 8-100% of thermoelectricity generated in most western states. Such displacement would increase stress on water resources if re-circulating evaporative cooling, the dominant cooling system in the thermoelectric sector, is adopted. Adoption of dry cooling, which accounts for 78% of geothermal capacity today, will limit changes in state-wide freshwater abstraction, but increase degraded water requirements. We suggest a research and development focus to develop advanced energy conversion and cooling technologies that reduce water use without imposing energy and consequent financial penalties. Policies should incentivize the development of higher enthalpy resources, and support identification of non-traditional degraded water sources and optimized siting of geothermal plants.

  15. Geothermal energy and its application opportunities in Serbia

    Directory of Open Access Journals (Sweden)

    Andrić Nenad M.

    2015-01-01

    Full Text Available Geothermal energy is accumulated heat in the fluid and rock masses in the Earth 's crust. The natural decay of radioactive elements (uranium, thorium and potassium in rocks produces heat energy. The simplest use of geothermal energy for heating is by heat pump. Geothermal energy can be used for production of electricity. It uses hot water and steam from the earth to run the generator. Serbia has significant potential for geothermal energy. The total amount of accumulated heat in geothermal resources in a depth of 3 km is two times higher than the equivalent thermal energy that could be obtained by burning all types of coal from all their sites in Serbia! The total abundance of geothermal resources in Serbia is 4000 l/s. Abundance of wells in Vojvodina is 10-20 l/s, and the temperature is from 40 to 60°C. Exploitation of thermal waters in Mačva could cause heating of following cities: Bogatić, Šabac, Sremska Mitrovica and Loznica, with a total population of 150.000 people. The richest hydrogeothermal resources are in Mačva, Vranje and Jošanička Banja. Using heat pumps, geothermal water can be exploited on the entire territory of Serbia! Although large producer, Serbia is importing food, ie., fruits and vegetables. With the construction of greenhouses, which will be heated with geothermal energy, Serbia can become an exporting country.

  16. Geothermal Energy: Current abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Ringe, A.C. (ed.)

    1988-02-01

    This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

  17. Effective geothermal heat

    International Nuclear Information System (INIS)

    Abelsen, Atle

    2006-01-01

    Scandinavia's currently largest geothermal heating project: the New Ahus hospital, is briefly presented. 300-400 wells on a field outside the hospital are constructed to store energy for both heating and cooling purposes

  18. NGDC Geothermal Data Bases

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geothermics is the study of heat generated in Earth's interior and its manifestation at the surface. The National Geophysical Data Center (NGDC) has a variety of...

  19. Geothermics in Aquitaine

    International Nuclear Information System (INIS)

    Dane, J.P.

    1995-01-01

    The geothermal exploitation of the Aquitanian Basin (S W France) started 15 years ago and has extended today to 12 different places. Three main aquifers of different depth are exploited in Bordeaux region: the old alluvial deposits of Garonne river (20-30 m), the Middle Eocene aquifer (300-400 m), and the Cenomanian-Turonian aquifer (900-1100 m) which is the deepest and most exploited for geothermal purposes. The drinkable quality of the water and the use of single-well technique are important factors that reduce the operating costs. Geothermics remains competitive with other energy sources due to the long-term stability of geothermal energy costs. (J.S.). 2 figs., 1 tab., 5 photos

  20. Performance analyses of a hybrid geothermal–fossil power generation system using low-enthalpy geothermal resources

    International Nuclear Information System (INIS)

    Liu, Qiang; Shang, Linlin; Duan, Yuanyuan

    2016-01-01

    Highlights: • Geothermal energy is used to preheat the feedwater in a coal-fired power unit. • The performance of a hybrid geothermal–fossil power generation system is analyzed. • Models for both parallel and serial geothermal preheating schemes are presented. • Effects of geothermal source temperatures, distances and heat losses are analyzed. • Power increase of the hybrid system over an ORC and tipping distance are discussed. - Abstract: Low-enthalpy geothermal heat can be efficiently utilized for feedwater preheating in coal-fired power plants by replacing some of the high-grade steam that can then be used to generate more power. This study analyzes a hybrid geothermal–fossil power generation system including a supercritical 1000 MW power unit and a geothermal feedwater preheating system. This study models for parallel and serial geothermal preheating schemes and analyzes the thermodynamic performance of the hybrid geothermal–fossil power generation system for various geothermal resource temperatures. The models are used to analyze the effects of the temperature matching between the geothermal water and the feedwater, the heat losses and pumping power during the geothermal water transport and the resource distance and temperature on the power increase to improve the power generation. The serial geothermal preheating (SGP) scheme generally generates more additional power than the parallel geothermal preheating (PGP) scheme for geothermal resource temperatures of 100–130 °C, but the SGP scheme generates slightly less additional power than the PGP scheme when the feedwater is preheated to as high a temperature as possible before entering the deaerator for geothermal resource temperatures higher than 140 °C. The additional power decreases as the geothermal source distance increases since the pipeline pumping power increases and the geothermal water temperature decreases due to heat losses. More than 50% of the power decrease is due to geothermal

  1. Geothermal environmental impact

    International Nuclear Information System (INIS)

    Armannsson, H.; Kristmannsdottir, H.

    1992-01-01

    Geothermal utilization can cause surface disturbances, physical effects due to fluid withdrawal noise, thermal effects and emission of chemicals as well as affect the communities concerned socially and economically. The environmental impact can be minimized by multiple use of the energy source and the reinjection of spent fluids. The emission of greenhouse gases to the atmosphere can be substantially reduced by substituting geothermal energy for fossil fuels as an industrial energy source wherever possible

  2. A complementary geothermal application

    International Nuclear Information System (INIS)

    Bedard, R.

    1998-01-01

    A geothermal project for air conditioning and heating at four health centres in Quebec was presented. The four health centres are: le centre Dominique-Tremblay, le centre Cardinal-Villeneuve, le centre Louis-Hebert, et le centre Francois-Charon. The investment made to install the geothermal heating and cooling system, the cost of operating the system, and energy savings resulting from the investment were discussed

  3. Geothermal progress monitor: Report No. 17

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    DOE is particularly concerned with reducing the costs of geothermal power generation, especially with the abundant moderate to low-temperature resources in the US. This concern is reflected in DOE`s support of a number of energy conversion projects. Projects which focus on the costs and performance of binary cycle technology include a commercial demonstration of supersaturated turbine expansions, which earlier studies have indicated could increase the power produced per pound of fluid. Other binary cycle projects include evaluations of the performance of various working fluid mixtures and the development and testing of advanced heat rejection systems which are desperately needed in water-short geothermal areas. DOE is also investigating the applicability of flash steam technology to low-temperature resources, as an economic alternative to binary cycle systems. A low-cost, low-pressure steam turbine, selected for a grant, will be constructed to utilize fluid discharged from a flash steam plant in Nevada. Another project addresses the efficiency of high-temperature flash plants with a demonstration of the performance of the Biphase turbine which may increase the power output of such installations with no increase in fluid flow. Perhaps the most noteworthy feature of this issue of the GPM, the 17th since its inception in 1980, is the high degree of industry participation in federally-sponsored geothermal research and development. This report describes geothermal development activities.

  4. Towards a de-carbonized energy system in North-Eastern Morocco: Prospective Geothermal Resource

    OpenAIRE

    Rimi, Abdelkrim; Zarhloule, Yassine; Barkaoui, Alae Eddine; Correia, António; Carneiro, Júlio; Verdoya, Massimo; Lucazeau, Francis

    2012-01-01

    Geothermal data has been indicating promising potentialities in the north-eastern Morocco. This paper presents new temperature data, recently recorded in water boreholes located in the Berkane and Oujda areas. Generally, the observed temperature gradients are rather high. One hole near Berkane, revealed an average geothermal gradient of more than 110 °C/km at depths greater than 300 m. This result confirms the geothermal gradient estimated in a mining borehole located about 30 km west of the ...

  5. FY 1999 report on the geothermal development promotion survey - Akinomiya area survey. Temperature/pressure logging before the long-term jetting test; 1999 nendo chinetsu kaihatsu sokushin chosa Akinomiya chiiki chosa hokokusho. Choki funshutsu shikenmae no ondo atsuryoku kenso

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-06-01

    As a part of the FY 1999 geothermal development promotion survey - Akinomiya area survey, the rising speed/vertical permeability of the fluid associated with the natural flow were calculated by grasping the temperature of geologic layers/reservoir pressure in the survey area and the temperature distribution for vertical depth. In the survey of boreholes in the Akinomiya area: N9-AY-3, N10-AY-6, N10-AY-7, N10-AY-8, temperature/pressure logging was conducted in the stationary state at the time when a lot of time passed after drilling, water-filling test and jetting test having been finished. In the temperature/pressure logging, the continued measurement was made using PTS logging device to simultaneously measure temperature/pressure/impeller revolution number and lowering measuring device. As a result of the survey, it was assumed that there is a possibility of occurrence of the borehole fluid flow around the depth of 980-1290m and 1320-1540m of N9-AY-3 and around the depth of 880-1090m of N10-AY-8. The rising speed and permeability of fluid from each well indicated the same order at three wells. (NEDO)

  6. Randomized controlled trial of the effects of high intensity and low-to-moderate intensity exercise on physical fitness and fatigue in cancer survivors: results of the Resistance and Endurance exercise After ChemoTherapy (REACT) study.

    Science.gov (United States)

    Kampshoff, Caroline S; Chinapaw, Mai J M; Brug, Johannes; Twisk, Jos W R; Schep, Goof; Nijziel, Marten R; van Mechelen, Willem; Buffart, Laurien M

    2015-10-29

    International evidence-based guidelines recommend physical exercise to form part of standard care for all cancer survivors. However, at present, the optimum exercise intensity is unclear. Therefore, we aimed to evaluate the effectiveness of a high intensity (HI) and low-to-moderate intensity (LMI) resistance and endurance exercise program compared with a wait list control (WLC) group on physical fitness and fatigue in a mixed group of cancer survivors who completed primary cancer treatment, including chemotherapy. Overall, 277 cancer survivors were randomized to 12 weeks of HI exercise (n = 91), LMI exercise (n = 95), or WLC (n = 91). Both interventions were identical with respect to exercise type, duration and frequency, and only differed in intensity. Measurements were performed at baseline (4-6 weeks after primary treatment) and post-intervention. The primary outcomes were cardiorespiratory fitness (peakVO2), muscle strength (grip strength and 30-second chair-stand test), and self-reported fatigue (Multidimensional Fatigue Inventory; MFI). Secondary outcomes included health-related quality of life, physical activity, daily functioning, body composition, mood, and sleep disturbances. Multilevel linear regression analyses were performed to estimate intervention effects using an intention-to-treat principle. In the HI and LMI groups, 74 % and 70 % of the participants attended more than 80 % of the prescribed exercise sessions, respectively (P = 0.53). HI (β = 2.2; 95 % CI, 1.2-3.1) and LMI (β = 1.3; 95 % CI, 0.3-2.3) exercise showed significantly larger improvements in peakVO2 compared to WLC. Improvements in peakVO2 were larger for HI than LMI exercise (β = 0.9; 95 % CI, -0.1 to 1.9), but the difference was not statistically significant (P = 0.08). No intervention effects were found for grip strength and the 30-second chair-stand test. HI and LMI exercise significantly reduced general and physical fatigue and reduced activity

  7. Heat flow and geothermal processes in Iceland

    Science.gov (United States)

    Flóvenz, Ólafur G.; Saemundsson, Kristján

    1993-09-01

    Heat flow values, derived from temperature measurements in shallow boreholes in Iceland, vary substantially across the country. The near-surface temperature gradients range from almost 0 to 500°C/km. The thermal conductivity of water-saturated rocks varies from 1.6 to 2.0 W/m°C. The temperature gradient in Iceland is mainly dependent on four factors: (1) the regional heat flow through the crust, (2) hydrothermal activity, (3) the permeability of the rock, and (4) residual heat in extinct volcanic centers. As Iceland is mainly made of basaltic material the radiogenic heat production is almost negligible. The thermal conductivity is, on the other hand, mainly influenced by the porosity of the rock; it increases as the porosity decreases. Iceland is made of sequences of flood basalts that formed within the volcanic rift zone—a continuation of the axis of the Mid-Atlantic ridge—and subsequently drifted sideways. Fresh basaltic lava is usually highly porous (30%) and fractured, and heat is mainly transported by convection. Therefore, a very low or even no temperature gradient is observed at shallow levels within the volcanic rift zone. As the basalt becomes buried the pores close due to lithostatic pressure and formation of secondary minerals. Below 500-1000 m depth in an uneroded lava pile, the heat is mainly transported by conduction. In the lowlands and valleys of Iceland outside the volcanic rift zone, 1000-1500 m of the original lava pile has been eroded, leaving thermal conduction as the most important heat transport mechanism. The regional temperature gradient has been measured in drillholes in dense and poorly permeable rocks away from the geothermal fields. The results show that the temperature gradient varies from 50 to 150°C/km. The highest values are found close to the volcanic rift zone and the gradient decreases with distance from the spreading axis. This result is mainly based on numerous shallow boreholes (60-500 m) but in some cases the results

  8. Geothermal Frontier: Penetrate a boundary between hydrothermal convection and heat conduction zones to create 'Beyond Brittle Geothermal Reservoir'

    Science.gov (United States)

    Tsuchiya, N.; Asanuma, H.; Sakaguchi, K.; Okamoto, A.; Hirano, N.; Watanabe, N.; Kizaki, A.

    2013-12-01

    EGS has been highlightened as a most promising method of geothermal development recently because of applicability to sites which have been considered to be unsuitable for geothermal development. Meanwhile, some critical problems have been experimentally identified, such as low recovery of injected water, difficulties to establish universal design/development methodology, and occurrence of large induced seismicity. Future geothermal target is supercritical and superheated geothermal fluids in and around ductile rock bodies under high temperatures. Ductile regime which is estimated beyond brittle zone is target region for future geothermal development due to high enthalpy fluids and relatively weak water-rock interaction. It is very difficult to determine exact depth of Brittle-Ductile boundary due to strong dependence of temperature (geotherm) and strain rate, however, ductile zone is considered to be developed above 400C and below 3 km in geothermal fields in Tohoku District. Hydrothermal experiments associated with additional advanced technology will be conducting to understand ';Beyond brittle World' and to develop deeper and hotter geothermal reservoir. We propose a new concept of the engineered geothermal development where reservoirs are created in ductile basement, expecting the following advantages: (a)simpler design and control the reservoir, (b)nearly full recovery of injected water, (c)sustainable production, (d)cost reduction by development of relatively shallower ductile zone in compression tectonic zones, (e)large quantity of energy extraction from widely distributed ductile zones, (f)establishment of universal and conceptual design/development methodology, and (g) suppression of felt earthquakes from/around the reservoirs. In ductile regime, Mesh-like fracture cloud has great potential for heat extraction between injection and production wells in spite of single and simple mega-fracture. Based on field observation and high performance hydrothermal

  9. Deep geothermal processes acting on faults and solid tides in coastal Xinzhou geothermal field, Guangdong, China

    Science.gov (United States)

    Lu, Guoping; Wang, Xiao; Li, Fusi; Xu, Fangyiming; Wang, Yanxin; Qi, Shihua; Yuen, David

    2017-03-01

    This paper investigated the deep fault thermal flow processes in the Xinzhou geothermal field in the Yangjiang region of Guangdong Province. Deep faults channel geothermal energy to the shallow ground, which makes it difficult to study due to the hidden nature. We conducted numerical experiments in order to investigate the physical states of the geothermal water inside the fault zone. We view the deep fault as a fast flow path for the thermal water from the deep crust driven up by the buoyancy. Temperature measurements at the springs or wells constrain the upper boundary, and the temperature inferred from the Currie temperature interface bounds the bottom. The deepened boundary allows the thermal reservoir to revolve rather than to be at a fixed temperature. The results detail the concept of a thermal reservoir in terms of its formation and heat distribution. The concept also reconciles the discrepancy in reservoir temperatures predicted from both quartz and Na-K-Mg. The downward displacement of the crust increases the pressure at the deep ground and leads to an elevated temperature and a lighter water density. Ultimately, our results are a first step in implementing numerical studies of deep faults through geothermal water flows; future works need to extend to cases of supercritical states. This approach is applicable to general deep-fault thermal flows and dissipation paths for the seismic energy from the deep crust.

  10. Tables of co-located geothermal-resource sites and BLM Wilderness Study Areas

    Energy Technology Data Exchange (ETDEWEB)

    Foley, D.; Dorscher, M.

    1982-11-01

    Matched pairs of known geothermal wells and springs with BLM proposed Wilderness Study Areas (WSAs) were identified by inspection of WSA and Geothermal resource maps for the states of Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming. A total of 3952 matches, for geothermal sites within 25 miles of a WSA, were identified. Of these, only 71 (1.8%) of the geothermal sites are within one mile of a WSA, and only an additional 100 (2.5%) are within one to three miles. Approximately three-fourths of the matches are at distances greater than ten miles. Only 12 of the geothermal sites within one mile of a WSA have surface temperatures reported above 50/sup 0/C. It thus appears that the geothermal potential of WSAs overall is minimal, but that evaluation of geothermal resources should be considered in more detail for some areas prior to their designation as Wilderness.

  11. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  12. Southwest Alaska Regional Geothermal Energy Projec

    Energy Technology Data Exchange (ETDEWEB)

    Holdmann, Gwen [Univ. of Alaska, Fairbanks, AK (United States)

    2015-04-30

    Drilling and temperature logging campaigns between the late 1970's and early 1980’s measured temperatures at Pilgrim Hot Springs in excess of 90°C. Between 2010 and 2014 the University of Alaska used a variety of methods including geophysical surveys, remote sensing techniques, heat budget modeling, and additional drilling to better understand the resource and estimate the available geothermal energy.

  13. Federal Geothermal Research Program Update Fiscal Year 2000

    Energy Technology Data Exchange (ETDEWEB)

    Renner, J.L.

    2001-08-15

    The Department of Energy's Geothermal Program serves two broad purposes: (1) to assist industry in overcoming near-term barriers by conducting cost-shared research and field verification that allows geothermal energy to compete in today's aggressive energy markets; and (2) to undertake fundamental research with potentially large economic payoffs. The four categories of work used to distinguish the research activities of the Geothermal Program during FY 2000 reflect the main components of real-world geothermal projects. These categories form the main sections of the project descriptions in this Research Update. Exploration Technology research focuses on developing instruments and techniques to discover hidden hydrothermal systems and to explore the deep portions of known systems. Research in geophysical and geochemical methods is expected to yield increased knowledge of hidden geothermal systems. Reservoir Technology research combines laboratory and analytical investigations with equipment development and field testing to establish practical tools for resource development and management for both hydrothermal reservoirs and enhanced geothermal systems. Research in various reservoir analysis techniques is generating a wide range of information that facilitates development of improved reservoir management tools. Drilling Technology focuses on developing improved, economic drilling and completion technology for geothermal wells. Ongoing research to avert lost circulation episodes in geothermal drilling is yielding positive results. Conversion Technology research focuses on reducing costs and improving binary conversion cycle efficiency, to permit greater use of the more abundant moderate-temperature geothermal resource, and on the development of materials that will improve the operating characteristics of many types of geothermal energy equipment. Increased output and improved performance of binary cycles will result from investigations in heat cycle research.

  14. Federal Geothermal Research Program Update Fiscal Year 2000; ANNUAL

    International Nuclear Information System (INIS)

    Renner, J.L.

    2001-01-01

    The Department of Energy's Geothermal Program serves two broad purposes: (1) to assist industry in overcoming near-term barriers by conducting cost-shared research and field verification that allows geothermal energy to compete in today's aggressive energy markets; and (2) to undertake fundamental research with potentially large economic payoffs. The four categories of work used to distinguish the research activities of the Geothermal Program during FY 2000 reflect the main components of real-world geothermal projects. These categories form the main sections of the project descriptions in this Research Update. Exploration Technology research focuses on developing instruments and techniques to discover hidden hydrothermal systems and to explore the deep portions of known systems. Research in geophysical and geochemical methods is expected to yield increased knowledge of hidden geothermal systems. Reservoir Technology research combines laboratory and analytical investigations with equipment development and field testing to establish practical tools for resource development and management for both hydrothermal reservoirs and enhanced geothermal systems. Research in various reservoir analysis techniques is generating a wide range of information that facilitates development of improved reservoir management tools. Drilling Technology focuses on developing improved, economic drilling and completion technology for geothermal wells. Ongoing research to avert lost circulation episodes in geothermal drilling is yielding positive results. Conversion Technology research focuses on reducing costs and improving binary conversion cycle efficiency, to permit greater use of the more abundant moderate-temperature geothermal resource, and on the development of materials that will improve the operating characteristics of many types of geothermal energy equipment. Increased output and improved performance of binary cycles will result from investigations in heat cycle research

  15. Utilising geothermal energy in Victoria

    International Nuclear Information System (INIS)

    Driscoll, Jim

    2006-01-01

    Geothermal energy is generated from the radioactive decay of naturally occurring isotopes and about 20% is generated from primordial heat associated with the formation of the earth. Geothermal project reduce energy and water cost and reduces greenhouse gas emissions

  16. Preliminary evaluation of geothermal resource in the Republic of Macedonia

    International Nuclear Information System (INIS)

    Georgieva, Mirjana; Micevski, Eftim; Gjorgiev, Dushko; Novkovski, Todor; Petrovski, Kiro

    1995-01-01

    Geothermal resources assessment is the estimation of the thermal energy in the ground, referenced to the mean annual temperature, coupled with an estimation of the amount of energy that might be extracted economically and legally at some reasonable future time. A resource assessment as a statement made at a given time using a given data. It is of only transitory value and must be updated periodically. Macedonia dispose a great amount of geothermal potential, but the geothermal investigation investments are totally reduced, resulting in an un sufficiently using of thermal waters. (Original)

  17. Optimal Management of Geothermal Heat Extraction

    Science.gov (United States)

    Patel, I. H.; Bielicki, J. M.; Buscheck, T. A.

    2015-12-01

    Geothermal energy technologies use the constant heat flux from the subsurface in order to produce heat or electricity for societal use. As such, a geothermal energy system is not inherently variable, like systems based on wind and solar resources, and an operator can conceivably control the rate at which heat is extracted and used directly, or converted into a commodity that is used. Although geothermal heat is a renewable resource, this heat can be depleted over time if the rate of heat extraction exceeds the natural rate of renewal (Rybach, 2003). For heat extraction used for commodities that are sold on the market, sustainability entails balancing the rate at which the reservoir renews with the rate at which heat is extracted and converted into profit, on a net present value basis. We present a model that couples natural resource economic approaches for managing renewable resources with simulations of geothermal reservoir performance in order to develop an optimal heat mining strategy that balances economic gain with the performance and renewability of the reservoir. Similar optimal control approaches have been extensively studied for renewable natural resource management of fisheries and forests (Bonfil, 2005; Gordon, 1954; Weitzman, 2003). Those models determine an optimal path of extraction of fish or timber, by balancing the regeneration of stocks of fish or timber that are not harvested with the profit from the sale of the fish or timber that is harvested. Our model balances the regeneration of reservoir temperature with the net proceeds from extracting heat and converting it to electricity that is sold to consumers. We used the Non-isothermal Unconfined-confined Flow and Transport (NUFT) model (Hao, Sun, & Nitao, 2011) to simulate the performance of a sedimentary geothermal reservoir under a variety of geologic and operational situations. The results of NUFT are incorporated into the natural resource economics model to determine production strategies that

  18. Accelerating Geothermal Research (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-05-01

    Geothermal research at the National Renewable Energy Laboratory (NREL) is advancing geothermal technologies to increase renewable power production. Continuous and not dependent on weather, the geothermal resource has the potential to jump to more than 500 gigawatts in electricity production, which is equivalent to roughly half of the current U.S. capacity. Enhanced geothermal systems have a broad regional distribution in the United States, allowing the potential for development in many locations across the country.

  19. Thermo-mechanical characterization of the lithosphere : Implications for geothermal resources

    NARCIS (Netherlands)

    Limberger, J.

    2018-01-01

    The two key ingredients needed to commercially exploit a geothermal energy system are (1) sufficiently high subsurface temperatures and (2) presence of rock formations suitable to act as a geothermal reservoir at reachable depths. Subsurface temperatures are controlled by the heat flowing from deep

  20. Next Generation Geothermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Brugman, John; Hattar, Mai; Nichols, Kenneth; Esaki, Yuri

    1995-09-01

    cycle. Results of this study indicate that dual flash type plants are preferred at resources with temperatures above 400 F. Closed loop (binary type) plants are preferred at resources with temperatures below 400 F. A rotary separator turbine upstream of a dual flash plant can be beneficial at Salton Sea, the hottest resource, or at high temperature resources where there is a significant variance in wellhead pressures from well to well. Full scale demonstration is required to verify cost and performance. Hot water turbines that recover energy from the spent brine in a dual flash cycle improve that cycle's brine efficiency. Prototype field tests of this technology have established its technical feasibility. If natural gas prices remain low, a combustion turbine/binary hybrid is an economic option for the lowest temperature sites. The use of mixed fluids appear to be an attractive low risk option. The synchronous turbine option as prepared by Barber-Nichols is attractive but requires a pilot test to prove cost and performance. Dual flash binary bottoming cycles appear promising provided that scaling of the brine/working fluid exchangers is controllable. Metastable expansion, reheater, Subatmospheric flash, dual flash backpressure turbine, and hot dry rock concepts do not seem to offer any cost advantage over the baseline technologies. If implemented, the next generation geothermal power plant concept may improve brine utilization but is unlikely to reduce the cost of power generation by much more than 10%. Colder resources will benefit more from the development of a next generation geothermal power plant than will hotter resources. All values presented in this study for plant cost and for busbar cost of power are relative numbers intended to allow an objective and meaningful comparison of technologies. The goal of this study is to assess various technologies on an common basis and, secondarily, to give an approximate idea of the current costs of the technologies at

  1. Use of a Geothermal-Solar Hybrid Power Plant to Mitigate Declines in Geothermal Resource Productivity

    Energy Technology Data Exchange (ETDEWEB)

    Dan Wendt; Greg Mines

    2014-09-01

    Many, if not all, geothermal resources are subject to decreasing productivity manifested in the form of decreasing brine temperature, flow rate, or both during the life span of the associated power generation project. The impacts of resource productivity decline on power plant performance can be significant; a reduction in heat input to a power plant not only decreases the thermal energy available for conversion to electrical power, but also adversely impacts the power plant conversion efficiency. The reduction in power generation is directly correlated to a reduction in revenues from power sales. Further, projects with Power Purchase Agreement (PPA) contracts in place may be subject to significant economic penalties if power generation falls below the default level specified. A potential solution to restoring the performance of a power plant operating from a declining productivity geothermal resource involves the use of solar thermal energy to restore the thermal input to the geothermal power plant. There are numerous technical merits associated with a renewable geothermal-solar hybrid plant in which the two heat sources share a common power block. The geo-solar hybrid plant could provide a better match to typical electrical power demand profiles than a stand-alone geothermal plant. The hybrid plant could also eliminate the stand-alone concentrated solar power plant thermal storage requirement for operation during times of low or no solar insolation. This paper identifies hybrid plant configurations and economic conditions for which solar thermal retrofit of a geothermal power plant could improve project economics. The net present value of the concentrated solar thermal retrofit of an air-cooled binary geothermal plant is presented as functions of both solar collector array cost and electricity sales price.

  2. First geothermal pilot power plant in Hungary

    Directory of Open Access Journals (Sweden)

    Tóth Anikó

    2007-01-01

    Full Text Available The Hungarian petroleum industry has always participated in the utilization of favourable geothermal conditions in the country. Most of the Hungarian geothermal wells were drilled by the MOL Ltd. as CH prospect holes. Accordingly, the field of geothermics belonged to the petroleum engineering, although marginally. It was therefore a surprise to hear of the decision of MOL Ltd. to build a geothermal power plant of about 2-5 MW. The tender was published in 2004.The site selected for the geothermal project is near the western border of an Hungarian oilfield, close to the Slovenian border. The location of the planned geothermal power plant was chosen after an analysis of suitable wells owned by the MOL Rt. The decision was made on the bases of different reservoir data. The existence of a reservoir of the necessary size, temperature, permeability, productivity and the water chemistry data was proved. The wells provide an enough information to understand the character of the reservoir and will be the production wells used by the planned power plant.The depth of the wells is about 2930 - 3200 m. The Triassic formation is reached at around 2851 m. The production and the reinjection wells are planned. The primary objective of the evaluation is to further learn the nature of the geothermal system. First a one-day discharge test is carried out. If this short-term test is successful, a six-months long-term discharge test will follow. The first period of the test is a transient phenomenon. Within the well test, the wellhead pressure, the flow rate, the outflowing water temperature, the dynamic fluid level, and the chemical components will be measured. The heat transfer around the bore-hole is influenced by the flow rate and the time. For the right appreciation of the measured data, it is very important to analyse the heat transfer processes around the bore-hole. The obtained data from the experiments must be also fitted into the framework of a mathematical

  3. FY 1998 report on the verification survey of geothermal exploration technology, etc. 2/2. Survey of deep geothermal resource; 1998 nendo chinetsu tansa gijutsu nado kensho chosa hokokusho. 2/2. Shinbu chinetsu shigen chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-12-01

    For the purpose of commercializing deep geothermal resource, a deep exploration well of 4000m class was drilled in the existing geothermal development area to survey the situation of deep geothermal resource existence and the availability. Concretely, the deep geothermal exploration well was drilled for study in the Kakkonda area, Shizukuishi town, Iwate prefecture, to clarify the situation of deep geothermal resource existence and the whole image of geothermal system. Consideration was made of the deep geothermal exploration method, systematization of deep high temperature drilling technology, and availability of deep geothermal resource. The results of the survey were summed up as follows: 1) general remarks; 2) deep exploration well drilling work; 3) details of the study. This report contained 3). In 3), the items were as follows: heightening of accuracy of the deep geothermal resource exploration method, making of a geothermal model in the Kakkonda area, study of deep drilling technology, study of deep fluid utilization technology, and making of a guide for deep geothermal resource exploration/development in the Kakkonda area. As to the technology of high temperature deep geothermal well drilling, studies were made of the borehole cooling method, mud water cooling method, survey of deterioration of casing with age, etc. (NEDO)

  4. Polymer-cement geothermal-well-completion materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zeldin, A.N.; Kukacka, L.E.

    1980-07-01

    A program to develop high-temperature polymer cements was performed. Several formulations based on organic and semi-inorganic binders were evaluated on the basis of mechanical and thermal stability, and thickening time. Two optimized systems exhibited properties exceeding those required for use in geothermal wells. Both systems were selected for continued evaluation at the National Bureau of Standards and contingent upon the results, for field testing in geothermal wells.

  5. West Texas geothermal resource assessment. Part II. Preliminary utilization assessment of the Trans-Pecos geothermal resource. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gilliland, M.W.; Fenner, L.B.

    1980-01-01

    The utilization potential of geothermal resources in Trans-Pecos, Texas was assessed. The potential for both direct use and electric power generation were examined. As with the resource assessment work, the focus was on the Hueco Tanks area in northeastern El Paso County and the Presidio Bolson area in Presidio County. Suitable users of the Hueco Tanks and Presidio Bolson resource areas were identified by matching postulated temperature characteristics of the geothermal resource to the need characteristics of existing users in each resource area. The amount of geothermal energy required and the amount of fossil fuel that geothermal energy would replace were calculated for each of the users identified as suitable. Current data indicate that temperatures in the Hueco Tanks resource area are not high enough for electric power generation, but in at least part of the Presidio Bolson resource area, they may be high enough for electric power generation.

  6. Geothermal heat pump

    International Nuclear Information System (INIS)

    Bruno, R.; Tinti, F.

    2009-01-01

    In recent years, for several types of buildings and users, the choice of conditioning by heat pump and low enthalpy geothermal reservoir has been increasing in the Italian market. In fact, such systems are efficient in terms of energy and consumption, they can perform, even at the same time, both functions, heating and cooling and they are environmentally friendly, because they do not produce local emissions. This article will introduce the technology and will focus on critical points of a geothermal field design, from actual practice, to future perspectives for the geo exchanger improvement. Finally, the article presents a best practice case in Bologna district, with an economic analysis showing the convenience of a geothermal heat pump. Conclusions of the real benefits of these plants can be drawn: compared to a non-negligible initial cost, the investment has a pay-back period almost always acceptable, usually less than 10 years. [it

  7. Geophysical contribution to evaluate the subsurface structural setting using magnetic and geothermal data in El-Bahariya Oasis, Western Desert, Egypt

    Directory of Open Access Journals (Sweden)

    Esmat Abd El All

    2015-12-01

    The geothermal studies in EL Bahariya-Oasis comprise subsurface temperature contour map which illustrates that the study area has geothermal groundwater reservoirs. The measurements of the geothermal properties for measured rock samples show that the rocks of the study area have moderate values of geothermal properties. This may be due to the seasonal variation in soil temperatures. These soil thermal properties depend on soil porosity and moisture content.

  8. The geothermal gradient map of Central Tunisia: Comparison with structural, gravimetric and petroleum data

    Science.gov (United States)

    Dhia, Hamed Ben

    1987-10-01

    Five hundred and fifty temperature values, initially measured as either bottom-hole temperatures (BHT) or drill-stem tests (DST), from 98 selected petroleum exploration wells form the basis of a geothermal gradient map of central Tunisia. A "global-statistical" method was employed to correct the BHT measurements, using the DST as references. The geothermal gradient ranges from 23° to 49°C/km. Comparison of the geothermal gradient with structural, gravimetric and petroleum data indicates that: (1) the general trend of the geothermal gradient curves reflects the main structural directions of the region, (2) zones of low and high geothermal gradient are correlated with zones of negative and positive Bouguer anomalies and (3) the five most important oil fields of central Tunisia are located near the geothermal gradient curve of 40° C/km. Such associations could have practical importance in petroleum exploration, but their significance must first be established through further investigation and additional data.

  9. Probes for the development of medium deep geothermal energy; Sonden zur Erschliessung der mitteltiefen Geothermie

    Energy Technology Data Exchange (ETDEWEB)

    Stuckmann, Uwe; Gottschalk, Daniel [REHAU AG und Co., Rehau (Germany)

    2011-10-24

    Compared to the near-surface geothermal energy, higher temperatures can be developed in the medium-depth geothermal energy (400 to 1,000 meters). Thus, the efficiency of geothermal power plants can be increased. The significantly higher yield performance and extraction performance are opposite to the higher costs of installation. At high thermal gradients of the surface one may completely dispense with the heat pump and directly heat. Geothermal probes at the current state of the art are reaching the limits of its applicability. Only newly developed geothermal probes offer a pressure resistance and temperature resistance in order to exploit these deeper regions. Such projects will be accompanied by the mining authority according to the power of approval. Extensive financial supports are available with the market incentive program of the Federal Government. Thus, the use of geothermal probes is possible in deeper regions. The feasibility and cost of future projects will be affected positively.

  10. Novel approaches for an enhanced geothermal development of residential sites

    Science.gov (United States)

    Schelenz, Sophie; Firmbach, Linda; Shao, Haibing; Dietrich, Peter; Vienken, Thomas

    2015-04-01

    An ongoing technological enhancement drives an increasing use of shallow geothermal systems for heating and cooling applications. However, even in areas with intensive shallow geothermal use, planning of geothermal systems is in many cases solely based on geological maps, drilling databases, and literature references. Thus, relevant heat transport parameters are rather approximated than measured for the specific site. To increase the planning safety and promote the use of renewable energies in the domestic sector, this study investigates a novel concept for an enhanced geothermal development of residential neighbourhoods. This concept is based on a site-specific characterization of subsurface conditions and the implementation of demand-oriented geothermal usage options. Therefore, an investigation approach has been tested that combines non-invasive with minimum-invasive exploration methods. While electrical resistivity tomography has been applied to characterize the geological subsurface structure, Direct Push soundings enable a detailed, vertical high-resolution characterization of the subsurface surrounding the borehole heat exchangers. The benefit of this site-specific subsurface investigation is highlighted for 1) a more precise design of shallow geothermal systems and 2) a reliable prediction of induced long-term changes in groundwater temperatures. To guarantee the financial feasibility and practicability of the novel geothermal development, three different options for its implementation in residential neighbourhoods were consequently deduced.

  11. On geothermal resources of India. Geotectonic aspects and recent developments

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, M L [National Geophysical Research Inst., Hyderabad (India)

    1988-11-10

    Research programs launched for exploration and development of the geothermal energy in India, since the 1973-1974 oil embargo, have led to the identification of many potential areas for geothermal resources. Resources comprise high/intermediate/low temperature hydrothermal convection and hot water aquifer systems, geopressured geothermal system and conduction-dominated regimes. Location and properties of these geothermal systems are controlled by the geodynamic and tectonic characteristics of the Indian continental lithosphere Main sectors for the utilization of India's proved and identified geothermal resources are the power generation, space heating, green house cultivation, aquaculture, poultry, sheep breeding, mineral processing, mushroom raising, processing of farm and forest produce, refrigeration, tourism, health-resorts and mineral water bottling. The R and D efforts have given some encouraging results. Geothermal resources of India, although primarily are of medium to low grade, could supplement, to a great extent, direct heat energy needs and may also provide electricity to some of the remote hilly areas. Development of geothermal energy sources in India is likely to get some more attention, with the setting up of separate departments and agencies, by various Provincial Governments, for R and D backing toward the alternate sources of energy.

  12. Interagency Geothermal Coordinating Council fifth annual report. Final draft

    Energy Technology Data Exchange (ETDEWEB)

    Abel, Fred H.

    1981-07-07

    Geothermal energy is the natural heat of the earth, and can be tapped as a clean, safe, economical alternative source of energy. Much of the geothermal energy resource is recoverable with current or near-current technology and could make a significant contribution both to increasing domestic energy supplies and to reducing the US dependence on imported oil. Geothermal energy can be used for electric power production, residential and commercial space heating and cooling, industrial process heat, and agricultural process applications. This report describes the progress for fiscal year 1980 (FY80) of the Federal Geothermal Program. It also summarizes the goals, strategy, and plans which form the basis for the FY81 and FY82 program activities and reflects the recent change in national policy affecting Federal research, development and demonstration programs. The Interagency Geothermal Coordinating Council (IGCC) believes that substantial progress can and will be made in the development of geothermal energy. The IGCC goals are: (1) reduce the institutional barriers so that geothermal projects can be on-line in one-half the current time; (2) make moderate temperature resources an economically competitive source of electricity; (3) remove the backlog of noncompetitive lease applications; (4) competitive lease all KGRA lands; and (5) cut the cost of hydrothermal technology by 25%.

  13. Analysis of Geothermal Pathway in the Metamorphic Area, Northeastern Taiwan

    Science.gov (United States)

    Wang, C.; Wu, M. Y.; Song, S. R.; Lo, W.

    2016-12-01

    A quantitative measure by play fairway analysis in geothermal energy development is an important tool that can present the probability map of potential resources through the uncertainty studies in geology for early phase decision making purpose in the related industries. While source, pathway, and fluid are the three main geologic factors in traditional geothermal systems, identifying the heat paths is critical to reduce drilling cost. Taiwan is in East Asia and the western edge of Pacific Ocean, locating on the convergent boundary of Eurasian Plate and Philippine Sea Plate with many earthquake activities. This study chooses a metamorphic area in the western corner of Yi-Lan plain in northeastern Taiwan with high geothermal potential and several existing exploration sites. Having high subsurface temperature gradient from the mountain belts, and plenty hydrologic systems through thousands of millimeters annual precipitation that would bring up heats closer to the surface, current geothermal conceptual model indicates the importance of pathway distribution which affects the possible concentration of extractable heat location. The study conducts surface lineation analysis using analytic hierarchy process to determine weights among various fracture types for their roles in geothermal pathways, based on the information of remote sensing data, published geologic maps and field work measurements, to produce regional fracture distribution probability map. The results display how the spatial distribution of pathways through various fractures could affect geothermal systems, identify the geothermal plays using statistical data analysis, and compare against the existing drilling data.

  14. Exergoeconomic optimization of integrated geothermal system in Simav, Kutahya

    International Nuclear Information System (INIS)

    Arslan, Oguz; Kose, Ramazan

    2010-01-01

    The aim of this study is to investigate the integrated use of the geothermal resources in the Kutahya-Simav region, Turkey. Although geothermal energy has been in use for years in the others countries, the integrated use of the geothermal fluid is new in Turkey. The high temperature level of the geothermal fluid in the Simav field makes it possible to utilize it for electricity generation, space heating and balneology. In this regard, a multiple complex has been proposed there in order to use the energy of the geothermal fluid more efficiently. Therefore, the possibility of electricity generation by a binary cycle has been preliminarily researched. After the electricity generation process, the waste geothermal fluid has been conducted to residences and greenhouses later for heating purpose in the field. In this regard, twenty one different models have been formed and analyzed using exergy and LCC methods. As a conclusion, the pre-feasibility study indicates that utilization of this geothermal capacity for multiple uses would be an attractive investment for Simav region.

  15. Spatial data analysis for exploration of regional scale geothermal resources

    Science.gov (United States)

    Moghaddam, Majid Kiavarz; Noorollahi, Younes; Samadzadegan, Farhad; Sharifi, Mohammad Ali; Itoi, Ryuichi

    2013-10-01

    Defining a comprehensive conceptual model of the resources sought is one of the most important steps in geothermal potential mapping. In this study, Fry analysis as a spatial distribution method and 5% well existence, distance distribution, weights of evidence (WofE), and evidential belief function (EBFs) methods as spatial association methods were applied comparatively to known geothermal occurrences, and to publicly-available regional-scale geoscience data in Akita and Iwate provinces within the Tohoku volcanic arc, in northern Japan. Fry analysis and rose diagrams revealed similar directional patterns of geothermal wells and volcanoes, NNW-, NNE-, NE-trending faults, hotsprings and fumaroles. Among the spatial association methods, WofE defined a conceptual model correspondent with the real world situations, approved with the aid of expert opinion. The results of the spatial association analyses quantitatively indicated that the known geothermal occurrences are strongly spatially-associated with geological features such as volcanoes, craters, NNW-, NNE-, NE-direction faults and geochemical features such as hotsprings, hydrothermal alteration zones and fumaroles. Geophysical data contains temperature gradients over 100 °C/km and heat flow over 100 mW/m2. In general, geochemical and geophysical data were better evidence layers than geological data for exploring geothermal resources. The spatial analyses of the case study area suggested that quantitative knowledge from hydrothermal geothermal resources was significantly useful for further exploration and for geothermal potential mapping in the case study region. The results can also be extended to the regions with nearly similar characteristics.

  16. Improving geothermal power plants with a binary cycle

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

    2015-12-01

    The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

  17. Geothermal and environment

    International Nuclear Information System (INIS)

    1993-01-01

    The production of geothermal-electric energy, presents relatively few contamination problems. The two bigger problems associated to the geothermal production are the disposition of waste fluids and the discharges to the atmosphere of non-condensable gases as CO 2 , H 2 O and NH 3 . For both problems the procedures and production technologies exist, like it is the integral use of brines and gases cleaning systems. Other problems consist on the local impact to forest areas for the effect of the vapor discharge, the contamination for noise, the contamination of aquifer shallow and the contamination related with the construction and termination of wells

  18. 2008 Geothermal Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Cross, J.; Freeman, J.

    2009-07-01

    This report describes market-wide trends for the geothermal industry throughout 2008 and the beginning of 2009. It begins with an overview of the U.S. DOE's Geothermal Technology Program's (GTP's) involvement with the geothermal industry and recent investment trends for electric generation technologies. The report next describes the current state of geothermal power generation and activity within the United States, costs associated with development, financing trends, an analysis of the levelized cost of energy (LCOE), and a look at the current policy environment. The report also highlights trends regarding direct use of geothermal energy, including geothermal heat pumps (GHPs). The final sections of the report focus on international perspectives, employment and economic benefits from geothermal energy development, and potential incentives in pending national legislation.

  19. Human Resources in Geothermal Development

    Energy Technology Data Exchange (ETDEWEB)

    Fridleifsson, I.B.

    1995-01-01

    Some 80 countries are potentially interested in geothermal energy development, and about 50 have quantifiable geothermal utilization at present. Electricity is produced from geothermal in 21 countries (total 38 TWh/a) and direct application is recorded in 35 countries (34 TWh/a). Geothermal electricity production is equally common in industrialized and developing countries, but plays a more important role in the developing countries. Apart from China, direct use is mainly in the industrialized countries and Central and East Europe. There is a surplus of trained geothermal manpower in many industrialized countries. Most of the developing countries as well as Central and East Europe countries still lack trained manpower. The Philippines (PNOC) have demonstrated how a nation can build up a strong geothermal workforce in an exemplary way. Data from Iceland shows how the geothermal manpower needs of a country gradually change from the exploration and field development to monitoring and operations.

  20. Geological interpretation of Mount Ciremai geothermal system from remote sensing and magneto-teluric analysis

    OpenAIRE

    Sumintadireja, Prihadi; Saepuloh, Asep; Irawan, Dasapta E.; Irawan, Diky; Fadillah, Ahmad

    2014-01-01

    The exploration of geothermal system at Mount Ciremai has been started since the early 1980s and has just been studied carefully since the early 2000s. Previous studies have detected the potential of geothermal system and also the groundwater mechanism feeding the system. This paper will discuss the geothermal exploration based on regional scale surface temperature analysis with Landsat image to have a more detail interpretation of the geological setting and magneto-telluric or MT survey at p...

  1. Major hydrogeochemical processes in the two reservoirs of the Yangbajing geothermal field, Tibet, China

    Science.gov (United States)

    Guo, Qinghai; Wang, Yanxin; Liu, Wei

    2007-10-01

    The Yangbajing geothermal field with the highest reservoir temperature in China is located about 90 km northwest to Lhasa City, capital of Tibet, where high temperature geothermal fluids occur both in shallow and deep reservoirs. The geophysical survey by the INDEPTH (International Deep Profiling of Tibet and the Himalayas) project group proved the existence of magmatic heat source at Yangbajing. In the study area, the hydrochemistry of cold surface waters and groundwaters and that of thermal groundwaters from both reservoirs are distinctively different. However, analysis of the relationship between enthalpy values and Cl concentrations of cold groundwaters and geothermal fluids indicates that the geothermal fluids from the shallow reservoir were formed as a result of mixing of cold groundwaters with geothermal fluids from the deep reservoir. In other words, the geothermal fluids from the deep reservoir flowed upwards into the shallow reservoir where it was diluted by the shallow cold groundwaters to form the shallow geothermal fluids with much lower temperature. A binary mixing model with two endmembers (the cold groundwaters and the deep geothermal fluids) was proposed and the mixing ratios for the geothermal fluid from each shallow well were estimated. Using the mixing ratios, the concentrations of some constituents in shallow geothermal fluids, such as As, B, SiO 2, SO 42- and F, were calculated and their differences with the actual concentrations were estimated. The results show that the differences between estimated and actual concentrations of As and B are small (the average absolute values being only 1.9% and 7.9%, respectively), whereas those of SiO 2, SO 42- and F are much bigger, indicating that other hydrogeochemical processes are responsible for the concentrations of these constituents. It is postulated that SiO 2 precipitation due to water temperature decrease, H 2S oxidation and ion exchange between OH - in geothermal waters and exchangeable F - in

  2. Research on geochemical exploration in geotherm development

    International Nuclear Information System (INIS)

    Hirowatari, Kazuo; Imaizumi, Yukio; Koga, Akito; Iwanaga, Tatsuto.

    1987-01-01

    The decisive factor of geotherm development is to improve the exploration techniques. By effectively carrying out the selection of promising development spots and the decision of well drilling positions, the geotherm development exceeding existing energy sources becomes feasible. There have been many problems in conventional geotherm exploration such as the high cost and long work period, therefore, it was decided to advance the research on geochemical exploration techniques which are relatively simple and can be carried out with low cost. When the techniques of geochemistry are used, for example, in the case that there are hot springs or fumaroles, the temperature, origin, properties and so on of underground hot water reservoirs can be estimated from their chemical composition. The method of examining the mercury concentration in soil and soil air has been in practical use in the geothermal districts where the ground surface symptom lacks. This time, the method of investigation using radon, thoron and gamma ray as the exploration indices was newly studied. The index compositions for geochemical exploration, new exploration index compositions, the method of measurement, the basic investigation and on-the-spot investigation are reported. (Kako, I.)

  3. National Geothermal Data System: Interactive Assessment of Geothermal Energy Potential in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Lee [Executive Office of the State of Arizona (Arizona Geological Survey); Richard, Stephen [Executive Office of the State of Arizona (Arizona Geological Survey); Clark, Ryan; Patten, Kim; Love, Diane; Coleman, Celia; Chen, Genhan; Matti, Jordan; Pape, Estelle; Musil, Leah

    2012-01-30

    Geothermal-relevant geosciences data from all 50 states (www.stategeothermaldata.org), federal agencies, national labs, and academic centers are being digitized and linked in a distributed online network via the U.S. Department of Energy-funded National Geothermal Data System (NGDS) to foster geothermal energy exploration and development through use of interactive online ‘mashups,’data integration, and applications. Emphasis is first to make as much information as possible accessible online, with a long range goal to make data interoperable through standardized services and interchange formats. An initial set of thirty geoscience data content models is in use or under development to define a standardized interchange format: aqueous chemistry, borehole temperature data, direct use feature, drill stem test, earthquake hypocenter, fault feature, geologic contact feature, geologic unit feature, thermal/hot spring description, metadata, quaternary fault, volcanic vent description, well header feature, borehole lithology log, crustal stress, gravity, heat flow/temperature gradient, permeability, and feature descriptions data like developed geothermal systems, geologic unit geothermal properties, permeability, production data, rock alteration description, rock chemistry, and thermal conductivity. Map services are also being developed for isopach maps, aquifer temperature maps, and several states are working on geothermal resource overview maps. Content models are developed preferentially from existing community use in order to encourage widespread adoption and promulgate minimum metadata quality standards. Geoscience data and maps from other NGDS participating institutions, or “nodes” (USGS, Southern Methodist University, Boise State University Geothermal Data Coalition) are being supplemented with extensive land management and land use resources from the Western Regional Partnership (15 federal agencies and 5 Western states) to provide access to a comprehensive

  4. Geothermic Characters Of The Most Promising Geothermal Filed For Power Generation In Republic Of Yemen

    Directory of Open Access Journals (Sweden)

    Al Kubati M.

    2017-07-01

    Full Text Available This paper presents geothermal exploration and their geothermometric characteristics in the western part of Yemen. Geologically this volcanic province totals areas approximately 45000 km2. Tectonically the study area is considered one of the most active in the Arabian Plate boundaries that affected by the opening of the Red Sea and the Gulf of Aden as well as by the African rift valley. Extensive field work had been carried out to evaluate the geothermal characteristics of this area. Water and gas samples were collected from hundreds of thermal springs and shallow domestic wells and geochemically analyzed and reported. Temperatures and PH values range from 35 to 96.3 C and from 4.5 to 8.5 respectively. Deep geothermal gradient indicates that the geothermal gradients in the western part of the province Red Sea coast are relatively high up to 182 C at the depth of 3290 m. Volcanic units are affected by hydrothermal processes and became intensively altered. By applying geothermometric methods four geothermal fields have been primarily identified they are Al-Lisi and Isbil Dhamar province Al-Qafr Ibb province Damt Dhala province and the Red Sea coast geothermal fields and three water types were recognized which are Na-HCO3-Cl-S and Ca-Na-Cl and Na HCO3.Results from Al-Lisi and Isbil geothermal area are considered the most promising field. Geothermal detail studies have been achieves and location of the first geothermal exploration well is located in Al-Lisi and Isbil field.By applyig geophisical methods Iso- Resistivity contour mapsthese maps reflected high resistivity areas and low.Clearly shows the low resistivity values incentral and Western part of the study area about 11amp937mWhile up Resistivity values to the area in the eastern 600amp937m.Also through the use ofthe different current electrode spacing AB2 700 1000 1500 and 2000m.We find the low- Resistivity areas becoming more widespread and concentrated in the center of the study area and

  5. FY 1993 report on the survey of geothermal development promotion. Survey of geothermal water (No.36 - Amemasu-dake area); 1993 nendo chinetsu kaihatsu sokushin chosa. Nessui no chosa hokokusho (No.36 Amemasu dake chiiki)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    As a part of the survey of geothermal development promotion in FY 1993, survey of geothermal fluid was made using a precise structure drilling well N5-AM-5 as exploration well in the Amemasu-dake area, Hokkaido. The induced jetting of geothermal fluid was carried out by the Swabbing method in the total number of times of 185 in 11 days at 10-20 times/day, but did not result in the jetting of geothermal water. The sampling of geothermal water was conducted by guiding the geothermal water that overflowed the guide pipe to the tank. The temperature of geothermal water indicated approximately 20 degrees C in the 1st time and 40-60 degrees C in and after the 2nd time every day. The electric conductivity of geothermal water was 2.033 mS/cm, chlorine ion concentration was 420-500 ppm, and pH value was 7.17-7.72. As a result of the survey, it was presumed that the geothermal water of this well originated in the meteoric water around the area and formed slightly supported by emitted volcanic matters. As to the geochemical temperature, the silica temperature indicated about 120 degrees C and the alkali ratio temperature did about 180 degrees C. It was considered that there possibly existed geothermal reservoirs of approximately 180 degrees C in alkali ratio temperature around the well. (NEDO)

  6. Experiences in the use of an electronic tool to measure pressure, temperature and spinner logs in the Mexican geothermal fields; Experiencias en el uso de sondas electronicas de presion, temperatura y flujo en campos geotermicos de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly; Jaimes Maldonado, Guillermo [Gerencia de Proyectos Geotermoelectricos, Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    1999-08-01

    In this article are exposed the results of an electronic tool to measure pressure-temperature and spinner profiles in the geothermal wells of Mexico, utilized in order to identify unobservable phenomena with traditional Kuster type pressure and temperature logs. Some examples of the applications are the identifications of production zones, interaction from between two or more zones of contribution under several conditions of operation, casing damages and apparition of sink flow intervals into the formation in producer wells. It is also presented the quantitative method utilized to calculate the masic contribution of the intervals of interest. [Spanish] En este articulo se exponen los resultados obtenidos mediante el uso de una sonda electronica para la medicion de presion-temperatura y flujo en los pozos geotermicos de Mexico, utilizada para identificar fenomenos que no son observables con las mediciones tradicionales tipo Kuster de presion y temperatura. Se ejemplifican algunas de las aplicaciones hechas, tales como la identificacion de zonas de produccion, forma de interaccion entre dos o mas zonas de aporte bajo diferentes condiciones de operacion, roturas en tuberias y aparicion de zonas ladronas en pozos. Se presenta brevemente el metodo cuantitativo utilizado para calcular el aporte masico de las intervalos de interes.

  7. Geothermal industry assessment

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-01

    An assessment of the geothermal industry is presented, focusing on industry structure, corporate activities and strategies, and detailed analysis of the technological, economic, financial, and institutional issues important to government policy formulation. The study is based principally on confidential interviews with executives of 75 companies active in the field. (MHR)

  8. Geothermal Greenhouse Information Package

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, K. [P.E.; Boyd, T. [ed.

    1997-01-01

    This package of information is intended to provide a foundation of background information for developers of geothermal greenhouses. The material is divided into seven sections covering such issues as crop culture and prices, operating costs for greenhouses, heating system design, vendors and a list of other sources of information.

  9. Geothermal energy. Program summary

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    Brief descriptions of geothermal projects funded through the Department of Energy during FY 1978 are presented. Each summary gives the project title, contractor name, contract number, funding level, dates, location, and name of the principal investigator, together with project highlights, which provide informaion such as objectives, strategies, and a brief project description. (MHR)

  10. Geothermal Grows Up

    Science.gov (United States)

    Johnson, William C.; Kraemer, Steven; Ormond, Paul

    2011-01-01

    Self-declared energy and carbon reduction goals on the part of progressive colleges and universities have driven ground source geothermal space heating and cooling systems into rapid evolution, as part of long-term climate action planning efforts. The period of single-building or single-well solutions is quickly being eclipsed by highly engineered…

  11. Geothermal energy conversion facility

    Energy Technology Data Exchange (ETDEWEB)

    Kutscher, C.F.

    1997-12-31

    With the termination of favorable electricity generation pricing policies, the geothermal industry is exploring ways to improve the efficiency of existing plants and make them more cost-competitive with natural gas. The Geothermal Energy Conversion Facility (GECF) at NREL will allow researchers to study various means for increasing the thermodynamic efficiency of binary cycle geothermal plants. This work has received considerable support from the US geothermal industry and will be done in collaboration with industry members and utilities. The GECF is being constructed on NREL property at the top of South Table Mountain in Golden, Colorado. As shown in Figure 1, it consists of an electrically heated hot water loop that provides heating to a heater/vaporizer in which the working fluid vaporizes at supercritical or subcritical pressures as high as 700 psia. Both an air-cooled and water-cooled condenser will be available for condensing the working fluid. In order to minimize construction costs, available equipment from the similar INEL Heat Cycle Research Facility is being utilized.

  12. Geothermal energy: opportunities for California commerce. Phase I report

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    California's geographic and end-use markets which could directly use low and moderate temperature geothermal resources are ranked and described, as well as those which have the highest potential for near-term commercial development of these resources. Building on previous market surveys, the assessment determined that out of 38 geothermal resource areas with characteristics for direct use development, five areas have no perceived impediments to near-term development: Susanville, Litchfield, Ontario Hot Springs, Lake Elsinore, and the Salton Sea Geothermal Field. Twenty-nine applications were compared with previously selected criteria to determine their near-term potential for direct use of geothermal fluids. Seven categories were found to have the least impediments to development; agriculture and district heating applications are considered the highest. Ten-year projections were conducted for fossil fuel displacement from the higher rated applications. It is concluded that greenhouses have the greatest displacement of 18 x 10/sup 6/ therms per year.

  13. Rodigo Uno (Italy) geothermal thermal energy for crop drying

    International Nuclear Information System (INIS)

    Facchini, U.; Sordelli, C.; Magnoni, S.; Cantadori, M.

    1992-01-01

    This paper outlines the chief design and performance features of a forage drying installation which makes use of locally available geothermal energy. The heat exchange is accomplished through a water-air exchanger directly fed by 59 degrees C geothermal springs. Two 80,000 cubic meter/hour ventilators, making use of this energy (58 to 38 degrees C heat exchange), raise the drying air temperature by 16 degrees C, while providing an overall drying capacity of 43,200 kg/day. The balance of available 38 degrees C geothermal energy is being employed by a local aquaculture farm. The paper comments on the economic and environmental benefits being derived from this direct utilization of geothermal energy

  14. Geothermal project will predetermine future of the Kosice heating plant

    International Nuclear Information System (INIS)

    Hirman, K.

    2003-01-01

    Geoterm, a.s. manager O. Halas describes economic and technical parameters of geothermal energy source by village Durkov near Kosice. It is planned to exploitate geothermal energy source for Kosicka heating plant (TEKO). Three basic variants of technical connecting to geothermal source are developed. Temperature at TEKO entrance should reach 125 degrees, annual heating energy supply will reach 2100 TJ and source output will reach 100 MWt, while admissible deviation at all indicators reaches 10%. The first geothermal energy should by supplied to TEKO in 2007. The investments overlapping 3 billions Slovak crowns are necessary to realize whole project. According to O. Halas a credit from World Bank guaranteed by state is crucial

  15. Geothermal ORC Systems Using Large Screw Expanders

    OpenAIRE

    Biederman, Tim R.; Brasz, Joost J.

    2014-01-01

    Geothermal ORC Systems using Large Screw Expanders Tim Biederman Cyrq Energy Abstract This paper describes a low-temperature Organic Rankine Cycle Power Recovery system with a screw expander a derivative of developed of Kaishan's line of screw compressors, as its power unit. The screw expander design is a modified version of its existing refrigeration compressor used on water-cooled chillers. Starting the ORC development program with existing refrigeration screw compre...

  16. 2014 Annual Report, Geothermal Technologies Office

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2015-03-01

    In 2014, the Geothermal Technologies Office (GTO) made significant gains—increased budgets, new projects, key technology successes, and new staff. The Fiscal Year (FY) 2015 budget is at $55 million—roughly a 20% increase over FY 2014, and a strong vote of confidence in what the sector is doing to advance economically competitive renewable energy. GTO also remains committed to a balanced portfolio, which includes new hydrothermal development, EGS, and targeted opportunities in the low-temperature sector.

  17. Use of Geothermal Energy for Aquaculture Purposes - Phase III

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, W C; Smith, K C

    1981-09-01

    This project, financed by the Pacific Northwest Regional Commission (PNRC), was designed to provide information to evaluate the best methods to use for intensive aquaculture of freshwater prawns, Macrobrachium rosenbergii, using geothermal energy. The freshwater prawn is a tropical organism and is native to southeast Asia. Earlier projects at Oregon Institute of Technology have shown the feasibility of culturing this aquatic animal in geothermal water. This phase of the project was designed to investigate intensive culture of this animal as well as the advantages of growing rainbow trout, ornamental tropical fin fish, and mosquito fish, Gambusia affnis, for vector control using geothermal energy. The research data collected on the prawns was obtained from the stocking and sampling of two 0.2- ha (half-acre) ponds constructed as a part of the project. The ponds are equipped with recording monitors for temperature and flow. The geothermal energy used is the geothermal effluent from the Oregon Institute of Technology heating system. This water is of potable quality and ranges in temperature from 50 to 70oC. The geothermal water used in the ponds is controlled at 27oC, ± 2oC, by using thermostats and solenoid valves. A small building next to the ponds contains facilities for hatching larvae prawns and tanks for growing post-larvae prawns. The hatchery facility makes the project self-sustaining. The hatchery was obtained as part of an earlier PNRC project.

  18. Use of geothermal heat for crop drying and related agricultural applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, T.J.; Wright, T.C.; Fein, E.; Munson, T.R.; Richmond, R.C.

    1978-03-01

    Observations led to the selection of the alfalfa dehydration industry for in-depth analysis of the application of moderate-temperature geothermal heat. Six geothermal heat exchanger/dryer configurations were examined. A low-temperature conveyor dryer using geothermal water to supply all required heat was chosen for site-specific analysis, the retrofitting of a large alfalfa dehydration plant within the Heber KGRA in the Imperial Valley, California. Even in the most favorable scenario--sharing a geothermal pipeline with the neighboring fertilizer plant--geothermal retrofitting would increase the price of the alfalfa ''dehy'' about 40 percent. The geothermal brine is estimated to cost $2.58/million Btu's compared with a 1977 natural gas cost of $1.15. Capital cost for heat exchangers and the new dryers is estimated at $3.3 million. The Heber plant appeared to offer the only good opportunity for geothermal retrofitting of an existing alfalfa dehydration plant. Construction of new plants at geothermal resource sites cannot be justified due to the uncertain state of the ''dehy'' industry. Use of geothermal heat for drying other crops may be much more promising. The potato dehydration industry, which is concentrated in the geothermal-rich Snake River Valley of Idaho, appears to offer good potential for geothermal retrofitting; about 4.7 x 10{sup 12}Btu's are used annually by plants within 50 miles of resources. Drying together at the geothermal wellhead several crops that have interlocking processing seasons and drying-temperature requirements may be quite attractive. The best ''multicrop drying center'' site identified was at Power Ranch Wells, Arizona; 34 other sites were defined. Agricultural processing applications other than drying were investigated briefly.

  19. Geothermal Economics Calculator (GEC) - additional modifications to final report as per GTP's request.

    Energy Technology Data Exchange (ETDEWEB)

    Gowda, Varun; Hogue, Michael

    2015-07-17

    This report will discuss the methods and the results from economic impact analysis applied to the development of Enhanced Geothermal Systems (EGS), conventional hydrothermal, low temperature geothermal and coproduced fluid technologies resulting in electric power production. As part of this work, the Energy & Geoscience Institute (EGI) has developed a web-based Geothermal Economics Calculator (Geothermal Economics Calculator (GEC)) tool that is aimed at helping the industry perform geothermal systems analysis and study the associated impacts of specific geothermal investments or technological improvements on employment, energy and environment. It is well-known in the industry that geothermal power projects will generate positive economic impacts for their host regions. Our aim in the assessment of these impacts includes quantification of the increase in overall economic output due to geothermal projects and of the job creation associated with this increase. Such an estimate of economic impacts of geothermal investments on employment, energy and the environment will also help us understand the contributions that the geothermal industry will have in achieving a sustainable path towards energy production.

  20. Health impacts of geothermal energy

    International Nuclear Information System (INIS)

    Layton, D.W.; Anspaugh, L.R.

    1982-01-01

    Geothermal resources are used to produce electrical energy and to supply heat for non-electric applications like residential heating and crop drying. The utilization of geothermal energy consists of the extraction of hot water or steam from an underground reservoir followed by different methods of surface processing along with the disposal of liquid, gaseous, and even solid wastes. The focus of this paper is on electric power production using geothermal resources greater than 150 0 C because this form of geothermal energy utilization has the most serious health-related consequences. Based on measurements and experience at existing geothermal power plants, atmospheric emissions of non-condensing gases such as hydrogen sulphide and benzene pose the greatest hazards to public health. Surface and ground waters contaminated by discharges of spent geothermal fluids constitute another health hazard. In this paper it is shown that hydrogen sulphide emissions from most geothermal power plants are apt to cause odour annoyances among members of the exposed public -some of whom can detect this gas at concentrations as low as 0.002 ppmv. A risk-assessment model is used to estimate the lifetime risk of incurring leukaemia from atmospheric benzene caused by 2000 MW(e) of geothermal development in California's Imperial Valley. Also assessed is the risk of skin cancer due to the ingestion of river water in New Zealand that is contaminated by waste geothermal fluids containing arsenic. Finally, data on the occurrence of occupational disease in the geothermal industry is briefly summarized. (author)

  1. Geothermal Anomaly Mapping Using Landsat ETM+ Data in Ilan Plain, Northeastern Taiwan

    Science.gov (United States)

    Chan, Hai-Po; Chang, Chung-Pai; Dao, Phuong D.

    2018-01-01

    Geothermal energy is an increasingly important component of green energy in the globe. A prerequisite for geothermal energy development is to acquire the local and regional geothermal prospects. Existing geophysical methods of estimating the geothermal potential are usually limited to the scope of prospecting because of the operation cost and site reachability in the field. Thus, explorations in a large-scale area such as the surface temperature and the thermal anomaly primarily rely on satellite thermal infrared imagery. This study aims to apply and integrate thermal infrared (TIR) remote sensing technology with existing geophysical methods for the geothermal exploration in Taiwan. Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) imagery is used to retrieve the land surface temperature (LST) in Ilan plain. Accuracy assessment of satellite-derived LST is conducted by comparing with the air temperature data from 11 permanent meteorological stations. The correlation coefficient of linear regression between air temperature and LST retrieval is 0.76. The MODIS LST product is used for the cross validation of Landsat derived LSTs. Furthermore, Landsat ETM+ multi-temporal brightness temperature imagery for the verification of the LST anomaly results were performed. LST Results indicate that thermal anomaly areas appear correlating with the development of faulted structure. Selected geothermal anomaly areas are validated in detail by field investigation of hot springs and geothermal drillings. It implies that occurrences of hot springs and geothermal drillings are in good spatial agreement with anomaly areas. In addition, the significant low-resistivity zones observed in the resistivity sections are echoed with the LST profiles when compared with in the Chingshui geothermal field. Despite limited to detecting the surficial and the shallow buried geothermal resources, this work suggests that TIR remote sensing is a valuable tool by providing an effective way of mapping

  2. Community Geothermal Technology Program: Fruit drying with geothermal energy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1988-03-14

    Largest problem was lack of proper recording and controlling instrumentation. Agricultural products tested were green papaya powder, banana slices, and pineapple slices. Results show that a temperature of 120 F is a good drying temperature. Papaya should be mature green and not overly ripe; banana ripeness is also important; and pineapple slice thickness should be very uniform for even drying. Geothermal drying is feasible. Figs, tabs.

  3. Geochemical studies of the geothermal area East of the Jombo Hill intrusion Coast Province. Final report

    International Nuclear Information System (INIS)

    Tole, M.P.

    1985-09-01

    Geothermal resources in Kenya can be classified into two types; (i) High temperature geothermal resources, found within the Kenyan section of Rift Valley System, and (ii) Low temperature geothermal resources found outside the main Rift Valley System (figure 1). The high temperature geothermal resources have received first priority in research and development, and this has culminated in their exploitation at the Olkaria Geothermal Field which currently generates 45 MW of electricity, representing approximately 18% of Kenya's electricity requirements. Further research is directed at opening up electricity generating plants within the Rift Valley Geothermal Systems occuring between Lake Bogoria and Lake Magadi. The low temperature geothermal resources have received less attention in Kenya. In some countries, low temperature geothermal resources have been utilised for a number of domestic and commercial undertakings (table 1), among them (a) space heating (b) recreational baths (c) sugar refining. In china, low temperature (less than 90 o C) geothermal reservoirs have been used to provide energy for electrical generating plants (Reed and Bliss, 1983). An examination of the distribution of the low temperature geothermal sites in Kenya (figure 1) indicates that most of them could be easily utilised for one or more of the domestic and commercial activities mentioned above, by virtue of their location. In order that recommendations regarding the type of use that each of these hotsprings can be put to can be made, proper evaluation of each site must be made: in particular the underground hotwater temperatures as well as the extent of the geothermal field at each site must be evaluated. Geochemical studies provide the cheapest (most cost-effective) method of geothermal energy exploration. The purpose of this project was to determine the extent of the hot zone, as well as the underground reservoir temperatures in the geothermal field North East of the Jomo Hill intrusion

  4. Feasibility study and energy efficiency estimation of geothermal power station based on medium enthalpy water

    Directory of Open Access Journals (Sweden)

    Borsukiewicz-Gozdur Aleksandra

    2007-01-01

    Full Text Available In the work presented are the results of investigations regarding the effectiveness of operation of power plant fed by geothermal water with the flow rate of 100, 150, and 200 m3/h and temperatures of 70, 80, and 90 °C, i. e. geothermal water with the parameters available in some towns of West Pomeranian region as well as in Stargard Szczecinski (86.4 °C, Poland. The results of calculations regard the system of geothermal power plant with possibility of utilization of heat for technological purposes. Analyzed are possibilities of application of different working fluids with respect to the most efficient utilization of geothermal energy. .

  5. Modeling of an Air Conditioning System with Geothermal Heat Pump for a Residential Building

    Directory of Open Access Journals (Sweden)

    Silvia Cocchi

    2013-01-01

    Full Text Available The need to address climate change caused by greenhouse gas emissions attaches great importance to research aimed at using renewable energy. Geothermal energy is an interesting alternative concerning the production of energy for air conditioning of buildings (heating and cooling, through the use of geothermal heat pumps. In this work a model has been developed in order to simulate an air conditioning system with geothermal heat pump. A ground source heat pump (GSHP uses the shallow ground as a source of heat, thus taking advantage of its seasonally moderate temperatures. GSHP must be coupled with geothermal exchangers. The model leads to design optimization of geothermal heat exchangers and to verify the operation of the geothermal plant.

  6. IMPACT OF GEOTHERMAL GRADIENT ON GROUND SOURCE HEAT PUMP SYSTEM MODELING

    OpenAIRE

    Tomislav Kurevija; Domagoj Vulin; Marija Macenić

    2014-01-01

    ndisturbed ground temperature is one of the most crucial thermogeological parameters needed for shallow geothermal resources assessment. Energy considered to be geothermal is energy stored in the ground at depths where solar radiation has no effect. At depth where undisturbed ground temperature occurs there is no influence of seasonal variations in air temperature from surface. Exact temperature value, and depth where it occurs, is functionally dependent on surface climate parameters and ther...

  7. Preliminary geothermal investigations at Manley Hot Springs, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    East, J.

    1982-04-01

    Manley Hot Springs is one of several hot springs which form a belt extending from the Seward Peninsula to east-central Alaska. All of the hot springs are low-temperature, water-dominated geothermal systems, having formed as the result of circulation of meteoric water along deepseated fractures near or within granitic intrusives. Shallow, thermally disturbed ground at Manley Hot Springs constitutes an area of 1.2 km by 0.6 km along the lower slopes of Bean Ridge on the north side of the Tanana Valley. This area includes 32 springs and seeps and one warm (29.1/sup 0/C) well. The hottest springs range in temperature from 61/sup 0/ to 47/sup 0/C and are presently utilized for space heating and irrigation. This study was designed to characterize the geothermal system present at Manley Hot Springs and delineate likely sites for geothermal drilling. Several surveys were conducted over a grid system which included shallow ground temperature, helium soil gas, mercury soil and resistivity surveys. In addition, a reconnaissance ground temperature survey and water chemistry sampling program was undertaken. The preliminary results, including some preliminary water chemistry, show that shallow hydrothermal activity can be delineated by many of the surveys. Three localities are targeted as likely geothermal well sites, and a model is proposed for the geothermal system at Manley Hot Springs.

  8. Geothermal heat can cool, too

    International Nuclear Information System (INIS)

    Wellstein, J.

    2008-01-01

    This article takes a look at how geothermal energy can not only be used to supply heating energy, but also be used to provide cooling too. The article reports on a conference on heating and cooling with geothermal energy that was held in Duebendorf, Switzerland, in March 2008. The influence of climate change on needs for heating and cooling and the need for additional knowledge and data on deeper rock layers is noted. The seasonal use of geothermal systems to provide heating in winter and cooling in summer is discussed. The planning of geothermal probe fields and their simulation is addressed. As an example, the geothermal installations under the recently renewed and extended 'Dolder Grand' luxury hotel in Zurich are quoted. The new SIA 384/6 norm on geothermal probes issued by the Swiss Association of Architects SIA is briefly reviewed.

  9. Temperature and heat flux changes at the base of Laurentide ice sheet inferred from geothermal data (evidence from province of Alberta, Canada)

    Czech Academy of Sciences Publication Activity Database

    Demezhko, D.; Gornostaeva, A.; Majorowicz, J.; Šafanda, Jan

    2018-01-01

    Roč. 107, č. 1 (2018), s. 113-121 ISSN 1437-3254 Institutional support: RVO:67985530 Keywords : borehole temperature * paleoclimate reconstruction * surface heat flux * ground surface temperature * Laurentide ice sheet Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.283, year: 2016

  10. Geothermal characterization of the coastal aquifer near Ravenna (Italy

    Directory of Open Access Journals (Sweden)

    M. Antonellini

    2012-12-01

    Full Text Available The coastal aquifer near Ravenna (Italy contains a large volume of groundwater (2,5x109 m3 whose quality has been compromised by sea-water intrusion. Today, the phreatic groundwater is mostly brackish with some lenses of freshwater floating on top of more saline water. This water, although impossible to use as drink-water or for irrigation, is still important to guarantee the health of wetland habitats and especially of the roman historical and coastal pine forests of Ravenna. With the objective of defining the flow pattern within the aquifer and the exchange between surface and ground water, we characterized the temperature distribution in the shallow subsurface by means of a dense network of piezometers. At the same time we had the opportunity to characterize the phreatic aquifer from the geothermal point of view, so that it could eventually be considered for use as a “low enthalpy” heat source. Heat pumps are able to extract heat during the winter and dissipate it during the summer. The temperature of the groundwater in the top layer of the aquifer (surficial zone is sensitive to the changes in atmospheric temperature throughout the year whereas the temperature of the deeper groundwater follows the geothermal gradient (geothermal zone. One of the scopes of the project is to discover at what depth is located the geothermal zone, so that the aquifer has a constant temperature throughout the year. A constant temperature is needed for storage of heat at low enthalpy. The thickness of the surficial zone and the temperature at the top of the geothermal zone are essentially related to land use, distance from the sea, sediment type, and amount of interaction between surface and groundwater. A knowledge of these factors allows to better exploit the geothermal potential of the aquifer when choosing the optimal placement of the heat pumps.

  11. Can Geothermal Power Replace Fossil Fuels?

    Science.gov (United States)

    Klenner, R.; Gosnold, W. D.

    2009-12-01

    Development of geothermal energy in any capacity is a positive step toward a sustainable energy future. The resource is enormous and has the capacity to supply most future demand for electrical power if technology can meet some substantial challenges. Electrical power from geothermal energy has several compelling characteristics: a small footprint, low emissions, continuous availability, and sustainability. However, a common perception of geothermal energy is that it is available only in a few isolated localities and thus cannot contribute significantly to future electrical power needs. This perception neglects the stored thermal energy available everywhere in the upper 10 km of Earth’s crust. We are investigating the potential for power production in oil-producing sedimentary basins where subsurface temperatures are sufficient for intermediate geothermal resources (90 °C -150 °C) at depths greater than 3 km. Existing estimates of geothermal energy stored at depth in sedimentary formations in the U.S. have been based only on a few aquifers and have not included the greater volume of fluids in oil-bearing formations. We reevaluated the accessible geothermal resource base for the north central US and found that including geothermal fluids in oil-producing formations increased the resource estimate by a factor of eight. Preliminary analysis of other basins indicates that the current estimate of thermal energy in the U.S. (100,000 EJ) may be of the order of 400,000 EJ. This is particularly significant due to recent technological advances leading to commercialization of scalable organic Rankine cycle (ORC) engines. Until recently, ORC systems were available only on an at large scale, i.e., 10s of MW, and had efficiencies of about 10 percent. Currently there are at least five manufacturers making scalable ORC systems in the 50 kW to 1 MW range, and at least one system has an efficiency of about 17 percent and is expected to attain an efficiency in the low 20s as it

  12. Chemical logging of geothermal wells

    Science.gov (United States)

    Allen, C.A.; McAtee, R.E.

    The presence of geothermal aquifers can be detected while drilling in geothermal formations by maintaining a chemical log of the ratio of the concentrations of calcium to carbonate and bicarbonate ions in the return drilling fluid. A continuous increase in the ratio of the concentrations of calcium to carbonate and bicarbonate ions is indicative of the existence of a warm or hot geothermal aquifer at some increased depth.

  13. Goechemical and Hydrogeochemical Properties of Cappadocia Geothermal Province

    Science.gov (United States)

    Furkan Sener, Mehmet; Sener, Mehmet; Uysal, Tonguc

    2016-04-01

    In order to determine the geothermal resource potential of Niǧde, Nevşehir and Aksaray provinces in Central Anatolian Volcanic Province (CAVP), geothermal fluids, surface water, and alteration rock samples from the Cappadocia volcanic zone in Turkey were investigated for their geochemical and stable isotopic characteristics in light of published geological and tectonic studies. Accordingly, the Cappadocia Geothermal Province (CGP) has two different geothermal systems located along tectonic zones including five active and two potential geothermal fields, which are located between Tuzgölü Fault Zone and Keçiboyduran-Melendiz Fault and north of Keçiboyduran-Melendiz Fault. Based on water chemistry and isotope compositions, samples from the first area are characterized by Ca-Mg-HCO3 ve Ca-HCO3 type mineral poor waters and Ca-Na-SO4 and Ca-Mg-SO4 type for the cold waters and the hot waters, respectively, whereas hot waters from the second area are Na-Cl-HCO3 and Ca-Na-HCO3 type mineral poor waters. According to δ18O and δ2H isotope studies, the geothermal waters are fed from meteoric waters. Results of silica geothermometer indicate that the reservoir temperature of Dertalan, Melendiz Mount, Keçiboyduran Mount, Hasan Mount (Keçikalesi), Ziga, Acıgöl, and Derinkuyu geothermal waters are 150-173 oC, 88-117 oC, 91-120 oC, 94-122 oC, 131-156 oC, 157-179 oC; 152-174 oC and 102-130 oC, respectively. The REE composition of geothermal fluids, surface water, and mineral precipitates indicate that temperature has a strong effect on REE fractionation of the sampled fluids. Eu- and Ce- anomalies (Eu/Eu*, Ce/Ce*) are visible in several samples, which are related to the inheritance from the host reservoir rocks and redox-controlled fractionation of these elements during water-rock interactions. REE and Yttrium geochemistry results of altered rock samples and water samples, which were taken from same locations exhibited quite similar features in each system. Hence, it was

  14. Direct application of geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Reistad, G.M.

    1980-01-01

    An overall treatment of direct geothermal applications is presented with an emphasis on the above-ground engineering. The types of geothermal resources and their general extent in the US are described. The potential market that may be served with geothermal energy is considered briefly. The evaluation considerations, special design aspects, and application approaches for geothermal energy use in each of the applications are considered. The present applications in the US are summarized and a bibliography of recent studies and applications is provided. (MHR)

  15. National Geothermal Data System: A Geothermal Data System for Exploration and Development

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Lee [Executive Office of the State of Arizona (Arizona Geological Survey); Richard, Stephen [Executive Office of the State of Arizona (Arizona Geological Survey); Patten, Kim [Executive Office of the State of Arizona (Arizona Geological Survey); Love, Diane [Executive Office of the State of Arizona (Arizona Geological Survey); Coleman, Celia [Executive Office of the State of Arizona (Arizona Geological Survey); Chen, Genhan [Executive Office of the State of Arizona (Arizona Geological Survey)

    2012-09-30

    Geothermal-relevant geosciences data from all 50 states (www.stategeothermaldata.org), federal agencies, national labs, and academic centers are being digitized and linked in a distributed online network funded by the U.S. Department of Energy Geothermal Data System (GDS) to foster geothermal energy exploration and development through use of interactive online ‘mashups,’data integration, and applications. Emphasis is first to make as much information as possible accessible online, with a long range goal to make data interoperable through standardized services and interchange formats. A growing set of more than thirty geoscience data content models is in use or under development to define standardized interchange formats for: aqueous chemistry, borehole temperature data, direct use feature, drill stem test, seismic event hypocenter, fault feature, geologic contact feature, geologic unit feature, thermal/hot spring description, metadata, quaternary fault, volcanic vent description, well header feature, borehole lithology log, crustal stress, gravity, heat flow/temperature gradient, permeability, and feature description data like developed geothermal systems, geologic unit geothermal characterization, permeability, production data, rock alteration description, rock chemistry, and thermal conductivity. Map services are also being developed for isopach maps, aquifer temperature maps, and several states are working on geothermal resource overview maps. Content models are developed based on existing community datasets to encourage widespread adoption and promulgate content quality standards. Geoscience data and maps from other GDS participating institutions, or “nodes” (e.g., U.S. Geological Survey, Southern Methodist University, Oregon Institute of Technology, Stanford University, the University of Utah) are being supplemented with extensive land management and land use resources from the Western Regional Partnership (15 federal agencies and 5 Western states) to

  16. Radiator Enhanced Geothermal System - A Revolutionary Method for Extracting Geothermal Energy

    Science.gov (United States)

    Karimi, S.; Marsh, B. D.; Hilpert, M.

    2017-12-01

    A new method of extracting geothermal energy, the Radiator Enhanced Geothermal System (RAD-EGS) has been developed. RAD-EGS attempts to mimic natural hydrothermal systems by 1) generating a vertical vane of artificially produced high porosity/permeability material deep in a hot sedimentary aquifer, 2) injecting water at surface temperatures to the bottom of the vane, where the rock is the hottest, 3) extracting super-heated water at the top of the vane. The novel RAD-EGS differs greatly from the currently available Enhanced Geothermal Systems in vane orientation, determined in the governing local crustal stress field by Shmax and Sl (meaning it is vertical), and in the vane location in a hot sedimentary aquifer, which naturally increases the longevity of the system. In this study, we explore several parameters regimes affecting the water temperature in the extraction well, keeping in mind that the minimum temperature of the extracted water has to be 150 °C in order for a geothermal system to be commercially viable. We used the COMSOL finite element package to simulate coupled heat and fluid transfer within the RAD-EGS model. The following geologic layers from top to bottom are accounted for in the model: i) confining upper layer, ii) hot sedimentary aquifer, and iii) underlying basement rock. The vane is placed vertically within the sedimentary aquifer. An injection well and an extraction well are also included in the simulation. We tested the model for a wide range of various parameters including background heat flux, thickness of geologic layers, geometric properties of the vane, diameter and location of the wells, fluid flow within the wells, regional hydraulic gradient, and permeability and porosity of the layers. The results show that among the aforementioned parameters, background heat flux and the depth of vane emplacement are highly significant in determining the level of commercial viability of the geothermal system. These results indicate that for the

  17. The geothermal KWh cost

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    Numerous factors can influence the cost of geothermal electricity production: the size and power of production units, the conversion technology used (Rankine cycle or water steam), the resource quality (dry vapor or water-vapor mixing), the resource depth, the drilling activity in the country and the work people costs. In the United States of America the geothermal kWh cost ranges from 2.5 to 8.5 US cents, while in Italy and Nicaragua it ranges from 3 and 10 cents and from 5.7 to 6 cents, respectively. Results of a comparative study of the kWh production cost from different energy sources is also summarized. (J.S.). 1 tab

  18. Federal Interagency Geothermal Activities

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Arlene [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Prencipe, Loretta [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Todaro, Richard M. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Cuyler, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Eide, Elizabeth [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2011-06-01

    This collaborative document describes the roles and responsibilities of key Federal agencies in the development of geothermal technologies including the U.S. Department of Energy (DOE); the U.S. Department of Agriculture (USDA), including the U.S. Forest Service; the U.S. Department of Interior (DOI), including the United States Geological Survey (USGS) and Bureau of Land Management (BLM); the Environmental Protection Agency (EPA); and the Department of Defense (DOD).

  19. Geothermal training at Auckland

    International Nuclear Information System (INIS)

    Hochstein, M.P.

    1990-01-01

    A total of 297 candidates from developing countries have attended the annual Geothermal Diploma Course at the University of Auckland between 1979 and 1989. Additional training in the form of post-graduate studies and short-term specialized courses has been given to 69 candidates from these countries between 1989 and 1989. In this paper performance indicators for the training are discussed, namely: demand, job retention rate, regional intake in relation to demand, and publication record of fellows

  20. Boron removal from geothermal waters by electrocoagulation

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, A. Erdem [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering., 25240 Erzurum (Turkey)], E-mail: aerdemy@atauni.edu.tr; Boncukcuoglu, Recep [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering., 25240 Erzurum (Turkey); Kocakerim, M. Muhtar [Atatuerk University, Faculty of Engineering, Department of Chemical Engineering, 25240 Erzurum (Turkey); Yilmaz, M. Tolga; Paluluoglu, Cihan [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering., 25240 Erzurum (Turkey)

    2008-05-01

    Most of the geothermal waters in Turkey contain extremely high concentration of boron when they are used for irrigation. The use of geothermal waters for irrigation can results in excess amount deposition of boron in soil. On the other hand, a minimal boron concentration is required for irrigational waters. In this study, electrocoagulation (EC) was selected as a treatment process for the removal of boron from thermal waters obtained from Ilica-Erzurum in Turkey. Current density (CD), pH of solution and temperature of solution were selected as operational parameters. The results showed that boron removal efficiency increased from pH 4.0 to 8.0 and decreased at pH 10.0. Although boron removal efficiency was highest at pH 8.0, energy consumption was very high at this pH value compared to other pH intervals. Boron removal efficiency reached to 95% with increasing current density from 1.5 to 6.0 mA/cm{sup 2}, but energy consumption was also increased in this interval. At higher temperatures of solution, such as 313 and 333 K, boron removal efficiency increased. At optimum conditions, boron removal efficiency in geothermal water reached up to 95%.

  1. Boron removal from geothermal waters by electrocoagulation

    International Nuclear Information System (INIS)

    Yilmaz, A. Erdem; Boncukcuoglu, Recep; Kocakerim, M. Muhtar; Yilmaz, M. Tolga; Paluluoglu, Cihan

    2008-01-01

    Most of the geothermal waters in Turkey contain extremely high concentration of boron when they are used for irrigation. The use of geothermal waters for irrigation can results in excess amount deposition of boron in soil. On the other hand, a minimal boron concentration is required for irrigational waters. In this study, electrocoagulation (EC) was selected as a treatment process for the removal of boron from thermal waters obtained from Ilica-Erzurum in Turkey. Current density (CD), pH of solution and temperature of solution were selected as operational parameters. The results showed that boron removal efficiency increased from pH 4.0 to 8.0 and decreased at pH 10.0. Although boron removal efficiency was highest at pH 8.0, energy consumption was very high at this pH value compared to other pH intervals. Boron removal efficiency reached to 95% with increasing current density from 1.5 to 6.0 mA/cm 2 , but energy consumption was also increased in this interval. At higher temperatures of solution, such as 313 and 333 K, boron removal efficiency increased. At optimum conditions, boron removal efficiency in geothermal water reached up to 95%

  2. Potential for Geothermal Energy in Myanmar

    International Nuclear Information System (INIS)

    Khin Soe Moe

    2010-12-01

    Geothermal energy is energy obtained by tapping the heat of the earth itself from kilometers deep into the earth's crust in some places of world. It is power extracted from heat stored in the earth. It is a renewable energy source because the heat is continuously produced inside the earth. Geothermal energy originates from the heat retained within the Earth's core since the orginal formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface. Most high temperature geothermal heat is harvested in regions close to tectonic plate boundaries where volcanic activity rises up to the surface of the Earth. It is one of the best renewable sources of energy and is capable of maintaining its temperature. The heating cost is very low. It uses less electricity and 75 per cent more efficient than the oil furnace and 48 per cent more efficient than the gas furnace. The energy is not only used for heating a place but also for cooling down the site. It generates uniform energy and creates no sound pollution. Maintenance cost is very cheap. The life of the underground piping is more than 50 year.

  3. Tracing fluid flow in geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Rose, P.E.; Adams, M.C. [Univ. of Utah, Salt Lake City, UT (United States)

    1997-12-31

    A family of fluorescent compounds, the polycyclic aromatic sulfonates, were evaluated for application in intermediate- and high-temperature geothermal reservoirs. Whereas the naphthalene sulfonates were found to be very thermally stable and reasonably detectable, the amino-substituted naphthalene sulfonates were found to be somewhat less thermally stable, but much more detectable. A tracer test was conducted at the Dixie Valley, Nevada, geothermal reservoir using one of the substituted naphthalene sulfonates, amino G, and fluorescein. Four of 9 production wells showed tracer breakthrough during the first 200 days of the test. Reconstructed tracer return curves are presented that correct for the thermal decay of tracer assuming an average reservoir temperature of 227{degrees}C. In order to examine the feasibility of using numerical simulation to model tracer flow, we developed simple, two-dimensional models of the geothermal reservoir using the numerical simulation programs TETRAD and TOUGH2. By fitting model outputs to measured return curves, we show that numerical reservoir simulations can be calibrated with the tracer data. Both models predict the same order of elution, approximate tracer concentrations, and return curve shapes. Using these results, we propose a method for using numerical models to design a tracer test.

  4. Detection of geothermal anomalies in Tengchong, Yunnan Province, China from MODIS multi-temporal night LST imagery

    Science.gov (United States)

    Li, H.; Kusky, T. M.; Peng, S.; Zhu, M.

    2012-12-01

    Thermal infrared (TIR) remote sensing is an important technique in the exploration of geothermal resources. In this study, a geothermal survey is conducted in Tengchong area of Yunnan province in China using multi-temporal MODIS LST (Land Surface Temperature). The monthly night MODIS LST data from Mar. 2000 to Mar. 2011 of the study area were collected and analyzed. The 132 month average LST map was derived and three geothermal anomalies were identified. The findings of this study agree well with the results from relative geothermal gradient measurements. Finally, we conclude that TIR remote sensing is a cost-effective technique to detect geothermal anomalies. Combining TIR remote sensing with geological analysis and the understanding of geothermal mechanism is an accurate and efficient approach to geothermal area detection.

  5. Geothermal direct-heat utilization assistance: Federal assistance program. Quarterly project progress report, October--December 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the first quarter of FY-96. It describes 90 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include geothermal heat pumps, space heating, greenhouses, aquaculture, equipment and resources. Research activities are summarized on low-temperature resource assessment, geothermal district heating system cost evaluation and silica waste utilization project. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, development of a webpage, and progress monitor reports on geothermal resources and utilization.

  6. NATIONAL GEOTHERMAL DATA SYSTEM (NGDS) GEOTHERMAL DATA DOMAIN: ASSESSMENT OF GEOTHERMAL COMMUNITY DATA NEEDS

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Arlene [United States Department of Energy; Blackwell, David [Southern Methodist University; Chickering, Cathy [Southern Methodist University; Boyd, Toni [Oregon Institute of Technology; Horne, Roland [Stanford University; MacKenzie, Matthew [Uberity Technology Corporation; Moore, Joseph [University of Utah; Nickull, Duane [Uberity Technology Corporation; Richard, Stephen [Arizona Geological survey; Shevenell, Lisa A. [University of Nevada, Reno

    2013-01-01

    To satisfy the critical need for geothermal data to ad- vance geothermal energy as a viable renewable ener- gy contender, the U.S. Department of Energy is in- vesting in the development of the National Geother- mal Data System (NGDS). This paper outlines efforts among geothermal data providers nationwide to sup- ply cutting edge geo-informatics. NGDS geothermal data acquisition, delivery, and methodology are dis- cussed. In particular, this paper addresses the various types of data required to effectively assess geother- mal energy potential and why simple links to existing data are insufficient. To create a platform for ready access by all geothermal stakeholders, the NGDS in- cludes a work plan that addresses data assets and re- sources of interest to users, a survey of data provid- ers, data content models, and how data will be ex- changed and promoted, as well as lessons learned within the geothermal community.

  7. Investigations of Very High Enthalpy Geothermal Resources in Iceland.

    Science.gov (United States)

    Elders, W. A.; Fridleifsson, G. O.

    2012-12-01

    The Iceland Deep Drilling Project (IDDP) is investigating the economic feasibility of producing electricity from supercritical geothermal reservoirs. Earlier modeling indicates that the power output of a geothermal well producing from a supercritical reservoir could potentially be an order of magnitude greater than that from a conventional hot geothermal reservoir, at the same volumetric flow rate. However, even in areas with an unusually high geothermal gradient, for normal hydrostatic pressure gradients reaching supercritical temperatures and pressures will require drilling to depths >4 km. In 2009 the IDDP attempted to drill the first deep supercritical well, IDDP-01, in the caldera of the Krafla volcano, in NE Iceland. However drilling had to be terminated at only 2.1 km depth when ~900°C rhyolite magma flowed into the well. Our studies indicate that this magma formed by partial melting of hydrothermally altered basalts within the Krafla caldera. Although this well was too shallow to reach supercritical pressures, it is highly productive, and is estimated to be capable of generating up to 36 MWe from the high-pressure, superheated steam produced from the upper contact zone of the intrusion. With a well-head temperature of ~440°C, it is at present apparently the hottest producing geothermal well in the world. A pilot plant is investigating the optimal utilization of this magmatically heated resource. A special issue of the journal Geothermics with 16 papers reporting on the IDDP-01 is in preparation. However, in order to continue the search for supercritical geothermal resources, planning is underway to drill a 4.5 km deep well at Reykjanes in SW Iceland in 2013-14. Although drilling deeper towards the heat source of this already developed high-temperature geothermal field will be more expensive, if a supercritical resource is found, this cost increase should be offset by the considerable increase in the power output and lifetime of the Reykjanes geothermal

  8. Hybrid Geothermal Heat Pumps for Cooling Telecommunications Data Centers

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, Koenraad J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zurmuhl, David P. [Cornell University; Lukawski, Maciej Z. [Cornell University; Aguirre, Gloria A. [Cornell University; Schnaars, George P. [Cornell University; Anderson, C. Lindsay [Cornell University; Tester, Jefferson W. [Cornell University

    2018-02-14

    The technical and economic performance of geothermal heat pump (GHP) systems supplying year-round cooling to representative small data centers with cooling loads less than 500 kWth were analyzed and compared to air-source heat pumps (ASHPs). A numerical model was developed in TRNSYS software to simulate the operation of air-source and geothermal heat pumps with and without supplementary air cooled heat exchangers - dry coolers (DCs). The model was validated using data measured at an experimental geothermal system installed in Ithaca, NY, USA. The coefficient of performance (COP) and cooling capacity of the GHPs were calculated over a 20-year lifetime and compared to the performance of ASHPs. The total cost of ownership (TCO) of each of the cooling systems was calculated to assess its economic performance. Both the length of the geothermal borehole heat exchangers (BHEs) and the dry cooler temperature set point were optimized to minimize the TCO of the geothermal systems. Lastly, a preliminary analysis of the performance of geothermal heat pumps for cooling dominated systems was performed for other locations including Dallas, TX, Sacramento, CA, and Minneapolis, MN.

  9. Isotope and hydrogeochemical studies of southern Jiangxi geothermal systems, China

    International Nuclear Information System (INIS)

    Zhou Wenbin; Li Xueli; Shi Weijun; Sun Zhanxue

    1999-01-01

    Southern Jiangxi is a geothermally active region, especially in Hengjing area. According to the work plan of IAEA Regional Collaboration in the Development of Geothermal Energy Resources and Environment Management through Isotope Techniques in East Asia and the Pacific (RAS-8-075), field investigation was carried out in Hengjing, southern Jiangxi Province, to demonstrate the use of isotope and geochemical techniques in low to medium tem