Geothermal District Heating Institutional Factors: The Klamath Falls Experience

Energy Technology Data Exchange (ETDEWEB)

Lienau, Paul J

1984-01-01

The city of Klamath Falls Geothermal District Heating System started to provide heat to 10 government buildings on March 20, 1984. This startup was two and one-half years after construction of the system was completed and the operation is scheduled for only a four-month test period. The delay was the result of citizens objecting to pumping and injecting geothermal fluids in the reservoir and was legally enforced by means of a city ordinance passed by the voters. This Initiative Ordinance essentially regulates the resource by requiring any additional water pumped from a geothermal well be returned to that same well. The state of Oregon filed a lawsuit against the city, claiming that state regulation preempted city action. The issue currently is in the Court of Appeals, after Klamath County Circuit Court ruled that the state was not preempted and the ordinance was valid and enforceable. Historical description of development that led up to these institutional and legal problems are discussed. Citizens objections and third party mitigation measures by means of reservoir engineering studies and public meetings are described. Lessons learned from the Klamath Falls experience are pointed out so future developments in other communities may benefit.

The potential of district heating using geothermal energy. A case study, Greece

International Nuclear Information System (INIS)

Agioutantis, Zacharias; Bekas, Athanassios

2000-01-01

The purpose of this study is to investigate the possibility of using low-enthalpy geothermal energy from the geothermal field of Sousaki in the province of Korinthos, Greece, to cover the thermal needs of the nearby town of Ag. Theodori. The possibility of developing a system of district heating was examined based on a proposed town model. Total thermal demands were calculated on the basis of a model dwelling and prevailing weather conditions in the area. Subsequently, a heat transfer circuit is proposed, including the distribution network, the heat exchanger, the production and reinjection pumps, and the pumping station. Finally, energy indices are presented, such as demand in tons of equivalent oil and CO 2 emissions. (Author)

Decreasing of energy consumption for space heating in existing residential buildings; Combined geothermal and gas district heating systems

International Nuclear Information System (INIS)

Rosca, Marcel

2000-01-01

The City of Oradea, Romania, has a population of about 230 000 inhabitants. Almost 70% of the total heat demand, including industrial, is supplied by a classical East European type district heating system. The heat is supplied by two low grade coal fired co-generation power plants. The oldest distribution networks and substitutions, as well as one power plant, are 35 years old and require renovation or even reconstruction. The geothermal reservoir located under the city supplies at present 2,2% of the total heat demand. By generalizing the reinjection, the production can be increased to supply about 8% of the total heat demand, without any significant reservoir pressure or temperature decline over 25 years. Another potential energy source is natural gas, a main transport pipeline running close to the city. Two possible scenarios are envisaged to replace the low grade coal by natural gas and geothermal energy as heat sources for Oradea. In one scenario, the geothermal energy supplies the heat for tap water heating and the base load for space heating in a limited number of substations, with peak load being produced by natural gas fired boilers. In the other scenario, the geothermal energy is only used for tap water heating. In both scenarios, all substations are converted into heat plants, natural gas being the main energy source. The technical, economic, and environmental assessment of the two proposed scenarios are compared with each other, as well as with the existing district heating system. Two other possible options, namely to renovate and convert the existing co-generation power plants to natural gas fired boilers or to gas turbines, are only briefly discussed, being considered unrealistic, at least for the short and medium term future. (Author)

Conventional heating systems is heating with geothermal water, v. 15(60)

International Nuclear Information System (INIS)

Hadzhimishev, Dimitar; Gashteovski, Ljupcho; Shami, Jotso

2007-01-01

The Geothermal Energy (GE) is a new renewable energy source with many advantages and specifics. Present mainly application of GE is in agriculture. In Geothermal System Kochani the GE uses for district heating and industrial uses also. There are many problems to solve before using the geothermal energy for district heating: direct application feasibility for heating rooms and industrial using existing heating installation system (90/70°C); the level of heating needs covering without installation reconstruction; techno-economical justification of this reconstruction ; covering of pike heating needs. The answers of these enigmas you have in this written effort. The results were practically justified in about ten object in Kochani. (Author)

Conventional heating systems is heating with geothermal water, v. 15(59)

International Nuclear Information System (INIS)

Hadzhimishev, Dimitar; Gashteovski, Ljupcho; Shami, Jotso

2007-01-01

The Geothermal Energy (GE) is a new renewable energy source with many advantages and specifics. Present mainly application of GE is in agriculture. In Geothermal System Kochani the GE uses for district heating and industrial uses also. There are many problems to solve before using the geothermal energy for district heating: direct application feasibility for heating rooms and industrial using existing heating installation system (90/70°C); the level of heating needs covering without installation reconstruction; techno-economical justification of this reconstruction ; covering of pike heating needs. The answers of these enigmas you have in this written effort. The results were practically justified in about ten object in Kochani. (Author)

Feasibility analysis of geothermal district heating for Lakeview, Oregon

Energy Technology Data Exchange (ETDEWEB)

1980-12-23

An analysis of the geothermal resource at Lakeview, Oregon, indicates that a substantial resource exists in the area capable of supporting extensive residential, commercial and industrial heat loads. Good resource productivity is expected with water temperatures of 200{degrees}F at depths of 600 to 3000 feet in the immediate vicinity of the town. Preliminary district heating system designs were developed for a Base Case serving 1170 homes, 119 commercial and municipal buildings, and a new alcohol fuel production facility; a second design was prepared for a downtown Mini-district case with 50 commercial users and the alcohol plant. Capital and operating costs were determined for both cases. Initial development of the Lakeview system has involved conducting user surveys, well tests, determinations of institutional requirements, system designs, and project feasibility analyses. A preferred approach for development will be to establish the downtown Mini-district and, as experience and acceptance are obtained, to expand the system to other areas of town. Projected energy costs for the Mini-district are $10.30 per million Btu while those for the larger Base Case design are $8.20 per million Btu. These costs are competitive with costs for existing sources of energy in the Lakeview area.

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

District heating systems - the necessary infrastructure for geothermal energy; Fern- und Nahwaermesysteme - notwendige Infrastruktur fuer die Geothermie

Energy Technology Data Exchange (ETDEWEB)

Schoenberg, I [Inst. fuer Umwelt-, Sicherheits- und Energietechnik e.V. (UMSICHT), Oberhausen (Germany)

1997-12-01

The contribution discusses the future chances of geothermal energy use with cost-optimized systems of geothermal energy + cogeneration + district heating and with the focus on innovation instead of state funding. (orig./AKF) [Deutsch] Der Beitrag bezieht sich auf die zukuenftigen Chancen der Geothermie, die eine kostenoptimierte Systemloesung Geothermie + KWK + Nah-/Fernwaerme sowie durch Mut zur Innovation und nicht durch Foerderung bestimmt werden. (orig./AKF)

Design of serially connected ammonia-water hybrid absorption-compression heat pumps for district heating with the utilisation of a geothermal heat source

DEFF Research Database (Denmark)

Jensen, Jonas Kjær; Ommen, Torben Schmidt; Markussen, Wiebke Brix

2016-01-01

District heating (DH) can reduce the primary energy consumption in urban areas with significant heat demands. The design of a serially connected ammonia-water hybrid absorption-compression heat pump system was investigated for operation in the Greater Copenhagen DH network in Denmark, in order...... to supply 7.2 MW heat at 85 °C utilizing a geothermal heat source at 73 °C. Both the heat source and heat sink experience a large temperature change over the heat transfer process, of which a significant part may be achieved by direct heat exchange. First a generic study with a simple representation...

Energetic, exergetic, economic and environmental evaluations of geothermal district heating systems: An application

International Nuclear Information System (INIS)

Keçebaş, Ali

2013-01-01

Highlights: ► Applying exergy, economic, environment and sustainability analyses to the GDHSs. ► Assessing energy and exergy efficiencies, economic and environmental impacts. ► Calculating the energy and exergy efficiencies of 34.86% and 48.78%, respectively. ► Proposing GDHSs as the most economic heating system. ► Providing a significant contribution towards reducing the emissions of air pollution. - Abstract: This study deals with an energetic and exergetic analysis as well as economic and environmental evaluations of Afyon geothermal district heating system (AGDHS) in Afyon, Turkey. In the analysis, actual system data are used to assess the district heating system performance, energy and exergy efficiencies, specific exergy index, exergetic improvement potential and exergy losses. And, for economic and environmental evaluations, actual data are obtained from the Technical Departments. The energy and exergy flow diagrams are clearly drawn to illustrate how much destructions/losses take place in addition to the inputs and outputs. For system performance analysis and improvement, both energy and exergy efficiencies of the overall AGDHS are determined to be 34.86% and 48.78%, respectively. The efficiency improvements in heat and power systems can help achieving energy security in an environmentally acceptable way by reducing the emissions that might otherwise occur. Present application has shown that in Turkey, geothermal energy is much cheaper than the other energy sources, like fossil fuels, and makes a significant contribution towards reducing the emissions of air pollution.

French know-how in the field of geothermal energy. District heating and electricity generation systems

International Nuclear Information System (INIS)

2012-08-01

This brochure is aimed at presenting the French expertise, public and private, at international level in the field of geothermal energy (district heating and electricity generation systems). It presents a summary of the French public policy framework, measures to support Research and Development, innovation and training and offers from private companies. It has been designed by the ADEME in cooperation with the French ministry for Ecology and Sustainable Development, the French association of geothermal energy professionals, Ubifrance (the French Agency for international business development) and the French renewable energies union

A Materials and Equipment Review of Selected U.S. Geothermal District Heating Systems

Energy Technology Data Exchange (ETDEWEB)

Rafferty, K D [P.E.

0000-12-30

Geothermal district heating systems are now quite common in the western U.S. A recent survey identified a total of 17 such systems. The performance of materials and equipment in 13 of these systems is reviewed in this paper. Specific areas covered include: production facilities, central plants, distribution, customer connection, metering and disposal. Those areas: characterized by the highest incidence of problems include: production well pumps, customer branch piping and energy metering.

Open heat exchanger for improved heat efficiency in geothermal spas

Energy Technology Data Exchange (ETDEWEB)

Nasrabady, S.J.; Palsson, H.; Saevarsdottir, G.A.

2008-09-15

Hot spas and Jacuzzis are popular in Iceland due to the abundance of reasonably prized geothermal heat available. However the water from the district heating system is too warm to be admitted directly into the spa. For safety reasons the water is mixed with cold water, in order to reduce temperature from about 80 deg C down to 45 deg C, which leads to wasting a large quantity of heat. Therefore a design is suggested here that enables the feeding of geothermal water directly into the spa, omitting the step of mixing it with cold water. The idea is to employ an open heat exchanger that transfers heat from the geothermal water to the bulk water in the spa, before letting it mix with the spa water. A case study was done for one particular spa. Heat load was calculated and measured when the spa was in use, and when it was unused. A design is suggested employing a circular double-plate which is to be placed at the bottom of the spa. This unit will function as an open heat exchanger feeding district heating water into the spa. Free convection takes place at the upper side of the upper plate and forced convection below the upper plate. Heat transfer coefficient for both was calculated. Using results from calculations, temperature distribution at critical parts of spa and plate was modeled. Results are reasonable and promising for a good design that may considerably reduce the energy expenses for a continuously heated geothermal spa

Institutional and financial guide to geothermal district heating. Serial No. 2

Energy Technology Data Exchange (ETDEWEB)

1982-03-01

General planning considerations which affect nearly every community are reviewed, and alternative operating structures which are available to communities are reviewed, including local governments, nonprofit cooperatives, private enterprises, and joint ventures. The financing options available to publicly-owned and privately-owned district heating systems are then summarized. The geothermal production and distribution activities most appropriate to each type of operating structure are reviewed, along with typical equity and debt funding sources. The tax advantages for private developers are described, as are the issures of customer contracts and service prices, and customer retrofit financing. The treatment is limited to an introductory overview. (LEW)

Selected cost considerations for geothermal district heating in existing single-family residential areas

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin

1996-06-01

In the past, district heating (geothermal or conventionally fueled) has not been widely applied to the single-family residential sector. Low-heat load density is the commonly cited reason for this. Although it's true that load density in these areas is much lower than for downtown business districts, other frequently overlooked factors may compensate for load density. In particular, costs for distribution system installation can be substantially lower in some residential areas due to a variety of factors. This reduced development cost may partially compensate for the reduced revenue resulting from low-load density. This report examines cost associated with the overall design of the system (direct or indirect system design), distribution piping installation, and customer branch lines. It concludes with a comparison of the costs for system development and the revenue from an example residential area.

Geothermal district heating system in Tanggu, Tianjin, China

International Nuclear Information System (INIS)

Jinrong, C.

1992-01-01

Tanggu is a harbor and industrial area and is the location of Tianjin Harbor, Tianjin Bonded Area and Tianjin Economic Development Area. It covers an area of 859 km 2 and has a population of 430,000. Tanggu Geothermal Field is located at the western coast of Bohai Sea. This area belongs to the depression area of North China geologically. Neogene strata of Guantao Group is distributed widely in this region. Good permeability, large thickness, and high conductivity make it form a regional low-temperature porous reservoir. The reservoir is buried to a depth of 1,600 - 2,100 m. The total thickness of about 500 m can be divided into upper and lower sections including three aquifers. Geothermal space heating tests of Tanggu started in 1980. Up to the present, there are a total of 16 geothermal wells in Tanggu. Thirteen of them were drilled in the shallower aquifer. The total production rate of thermal water is 3.636 x 10 6 m 3 annually. The net production rate used for space heating is 3.10 x 10 6 m 3 from 11 wells. It has heated an area of 620 x 10 3 m 2 and has solved winter heating for 100 thousand people

Geothermal energy and district heating in Ny-Ålesund, Svalbard

OpenAIRE

Iversen, Julianne

2013-01-01

This thesis presents the possibilities for using shallow geothermal energy for heating purposes in Ny-Ålesund. The current energy supply in Ny-Ålesund is a diesel generator, which does not comply with the Norwegian government and Ny-Ålesund Science Managers Committee’s common goal to maintain the natural environment in Ny-Ålesund. Ny-Ålesund has a potential for replacing the heat from the current diesel based energy source with geothermal energy. Geothermal energy is considered to have low im...

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.)

Geothermal Direct Heat Application Potential

Energy Technology Data Exchange (ETDEWEB)

Lienau, Paul J

1989-01-01

The geothermal direct-use industry growth trends, potential, needs, and how they can be met, are addressed. Recent investigations about the current status of the industry and the identification of institutional and technical needs provide the basis on which this paper is presented. Initial drilling risk is the major obstacle to direct-use development. The applications presented include space and district heating projects, heat pumps (heating and cooling), industrial processes, resorts and pools, aquaculture and agriculture.

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.

Nuclear and geothermal energy as a direct heat source

International Nuclear Information System (INIS)

Field, A.A.

1976-01-01

After some remarks on economic aspects, the swimming pool reactor simplified for the purpose of heat generation is described, the core of which supplies heat of 100-120 0 C for district heating. In this context, ways of storing waste heat are discussed. The alternative is pointed out that energy may be transferred by means of hydrogen. In conclusion, it is demonstrated on a French plant how geothermal water can be used directly via heat exchangers for district heating. (UA/LN) [de

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

Energy Technology Data Exchange (ETDEWEB)

1993-08-01

Progress is reported on the following R&D activities: evaluation of lineshaft turbine pump problems, geothermal district heating marketing strategy, and greenhouse peaking analysis. Other activities are reported on technical assistance, technology transfer, and the geothermal progress monitor.

Performance investigation of the Turkish geothermal district heating systems (GDHSs). Paper no. IGEC-1-066

International Nuclear Information System (INIS)

Ozgener, L.; Hepbasli, A.; Dincer, I.

2005-01-01

Various energy and exergy modeling techniques have been used by many investigators for energy-utilization assessments to minimize losses and maximize energy savings and hence financial savings. Furthermore, performance indices are employed to detect and to evaluate quantitatively the causes of the thermodynamic imperfection of the process under consideration such as exergy analysis. The present study evaluates the performances of the two geothermal district heating systems (GDHSs) installed in Turkey. The GDHSs considered are the Balcova GDHS in Izmir and Salihli GDHS in Manisa, while the exergetic improvement potential (ExIP) and specific exergy index (SExI) are used for the modeling of the entire systems and their essential components for performance evaluations and comparisons as well as possible energy and exergy efficiency improvements. The SExI is found to be 0.07 and 0.049 for the Balcova and Salihli GDHSs, respectively, representing that Balcova and Salihli geothermal fields fall into the medium and low quality geothermal resources according to the Lee's classification, respectively. The values for the ExIP are also obtained as follows: For the BGDHS with thirteen plate-type heat exchangers, fourth heat exchanger has the largest ExIP rate as 69.96 kW, followed by the first, second, and third heat exchangers at 20.07, 11.71, and 4.05 kW capacities, respectively, with the remaining ones under 3 kW, which does not present much potential for improvement. For the SGDHS, the ExIP rate is found to be 106.04 kW for the plate-type heat exchanger. On the other hand, in order to improve the system efficiency, water leaks in the distribution network should be prevented. (author)

FY1998 research report on the basic research on geothermal district heating in Kamchatka, Russia; 1998 nendo Roshia Renpo Kamchatka shu ni okeru chinetsu riyo ni yoru chiiki danbo ni kansuru kiso chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

Petropavlovsk-Kamchatky (P-K) city in Kamchatka, Russia is operating hot-water district heating using heavy oil boilers and waste hot water of thermal power plants as heat sources. Feasibility study was made on district heating using natural geothermal hot water and/or geothermal heat pump systems as heat sources of hot water supply for reduction of greenhouse effect gas emission. Among 3 areas including geothermal hot water, use of hot water in K area was impossible because of lower temperature and less spring water. Use of hot water in P and UP areas was impossible as primary hot water because of temperature drop to 64 degrees C during hot water supply toward P-K city. The building heating operation test was carried out using the geothermal heat pump system installed in a newly drilled heat exchange well of 100m deep. As a result, sufficient heat recovery was achieved for heating. If all of 49 boiler houses for heating are replaced with such geothermal heat pump systems, CO{sub 2} reduction was estimated to be 520,000t/y. (NEDO)

Direct Heat Utilization of Geothermal Resources Worldwide 2005

Energy Technology Data Exchange (ETDEWEB)

Lund, John W.

2000-01-01

Direct utilization of geothermal energy consists of various forms for heating and cooling instead of converting the energy for electric power generation. The geothermal resources that can be utilized are in the lower temperature range that are more wide-spread than the higher temperature resources used for electricity generation. The major areas of direct utilization are: heating of swimming pools and for balneology; space heating and cooling including district heating; agriculture applications (greenhouse heating and crop drying); aquaculture applications; industrial processing; and geothermal heat pumps. Direct utilization projects are reported in 72 countries with an installed capacity of 28,268 MWt and annual energy use of 273,372 TJ (75,943 GWh) reported in 2005. The equivalent annual savings in fuel oil amounts to 170 million barrels (25.4 million tonnes) and 24 million tonnes in carbon emissions to the atmosphere. Recent trends are to combined geothermal heat and power projects in order to maximize the use of the resource and improve the economics of the project. With the recent increases in fossil fuel prices, it is estimated that direct utilizations will more than double in the next 10 years.

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.

Geothermal structure in the Nakagawa District, Tanzawa Mountains

Energy Technology Data Exchange (ETDEWEB)

Oki, Y; Ohguchi, T; Hirota, S; Ogino, K; Hirano, T; Moriya, M

1967-03-01

A geothermal structure is synthesized to assess the areal extent of hydrothermal activity in the Nakagawa district. A temperature anomaly was encountered in a narrow area (1 km x 0.5 km) along a fractured zone filled with numerous veins of Ca-zeolite; thermal water is flowing out through this zone. The energy release is evaluated to be 186.7 kcal/sec for discharged thermal water and 15.2 kcal/sec for conductive heat flow. The hydrothermal activity of the area is essentially a result of the conduction of thermal energy in a widely extending, though weak geothermal area (6 to 8/sup 0/C/100m). It is necessary to assume an anomalous area of about 10 km/sup 2/ in the activity of the Nakagawa District. Thermal energy absorbed in water comes to a focus and moves toward the surface through the fractured zone. In the Tanzawa mountains the terrestrial heat flow of the region of plutonic rocks (3.3 h.u.) is more than three times greater than that of the sedimentary region (about 1 h.u.).

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.

Feasibility of geothermal space/water heating for Mammoth Lakes Village, California. Final report, September 1976--September 1977

Energy Technology Data Exchange (ETDEWEB)

Sims, A.V.; Racine, W.C.

1977-12-01

Results of a study to determine the technical, economic, and environmental feasibility of geothermal district heating for Mammoth Lakes Village, California are reported. The geothermal district heating system selected is technically feasible and will use existing technology in its design and operation. District heating can provide space and water heating energy for typical customers at lower cost than alternative sources of energy. If the district heating system is investor owned, lower costs are realized after five to six years of operation, and if owned by a nonprofit organization, after zero to three years. District heating offers lower costs than alternatives much sooner in time if co-generation and/or DOE participation in system construction are included in the analysis. During a preliminary environmental assessment, no potential adverse environmental impacts could be identified of sufficient consequence to preclude the construction and operation of the proposed district heating system. A follow-on program aimed at implementing district heating in Mammoth is outlined.

Geothermal direct-heat utilization assistance. Quarterly project progress report, October--December 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-01

This report summarizes geothermal technical assistance, R and D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the first quarter of FY-98 (October--December 1997). It describes 216 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with include requests for general information including maps and material for high school debates, and material on geothermal heat pumps, resource and well data, space heating and cooling, greenhouses, aquaculture, equipment, district heating, resorts and spas, industrial applications, electric power and snow melting. Research activities include work on model construction specifications of lineshaft submersible pumps and plate heat exchangers, a comprehensive aquaculture developer package and revisions to the Geothermal Direct Use Engineering and Design Guidebook. Outreach activities include the publication of the Quarterly Bulletin (Vol. 18, No. 4) which was devoted entirely to geothermal activities in South Dakota, dissemination of information mainly through mailings of publications, tours of local geothermal uses, geothermal library acquisition and use, participation in workshops, short courses and technical meetings by the staff, and progress monitor reports on geothermal activities.

Regulatory aspects, an important factor for geothermal energy application for district heating development. European insurance scheme to cover geological risk related to geothermal operations

International Nuclear Information System (INIS)

Popovski, Kiril

2000-01-01

District heating is one of the most interesting fields of geothermal energy application development in Europe. However, besides the technical/technological/economical and organizational aspects of the problem in question, the related legal and regulatory aspects influence very much the real possibilities for wider introduction of this energy source in the state energy balances in most of the countries. Based on the official EU report for the State-of-the-art of the problem of the insurance to cover geological risks and necessary aspects to be developed and resolved in a better and 'common' way in order to enable higher investments in bigger projects (district heating) development, the paper presents the situation in different European countries in relation to the Macedonian one. Conclusions extracted should give a positive contribution to the process of the Macedonian laws accommodation to the common EU practice. (Author)

Hoosac tunnel geothermal heat source. Final report

Energy Technology Data Exchange (ETDEWEB)

1982-06-10

The Hoosac Rail Tunnel has been analyzed as a central element in a district heating system for the City of North Adams. The tunnel has been viewed as a collector of the earth's geothermal heat and a seasonal heat storage facility with heat piped to the tunnel in summer from existing facilities at a distance. Heated fluid would be transported in winter from the tunnel to users who would boost the temperature with individual heat pumps. It was concluded the tunnel is a poor source of geothermal heat. The maximum extractable energy is only 2200 million BTU (20000 gallons of oil) at 58/sup 0/F. The tunnel is a poor heat storage facility. The rock conductivity is so high that 75% of the heat injected would escape into the mountain before it could be recaptured for use. A low temperature system, with individual heat pumps for temperature boost could be economically attractive if a low cost fuel (byproduct, solid waste, cogeneration) or a cost effective seasonal heat storage were available.

A review on energetic, exergetic and exergoeconomic aspects of geothermal district heating systems (GDHSs)

International Nuclear Information System (INIS)

Hepbasli, Arif

2010-01-01

Geothermal is a reliable and promising renewable energy. In 1892 the first geothermal district heating system (GDHS) began operations in Boise, Idaho, USA. Since then, a number of GDHSs installations have been made worldwide. Various investigations on the efficient utilization of geothermal energy resources have also been conducted to attain sustainable development. There is a link between exergy and sustainable development. In recent years, exergy analysis has been widely used in the design, simulation and performance assessment of thermal systems. Exergoeconomic analysis, which is a combination of exergy and economics, is nowadays considered a powerful tool to study and optimize various types of energy-related systems. The present study comprehensively reviews GDHSs in terms of three aspects, namely energetic, exergetic and exergoeconomic analyses and assessments, for the first time to the best of the author's knowledge. A brief historical development of the studies on GDHSs was given on the base of these three aspects first. Next, GDHSs analyzed were schematically presented and shortly described. The previously conducted studies on GDHSs were then reviewed and classified. Finally, the conclusions were presented. It is expected that this comprehensive study will be very beneficial to everyone involved or interested in the energetic, exergetic and exergoeconomic design, analysis and performance evaluation of GDHSs.

Design and optimization of geothermal power generation, heating, and cooling

Science.gov (United States)

Kanoglu, Mehmet

Most of the world's geothermal power plants have been built in 1970s and 1980s following 1973 oil crisis. Urgency to generate electricity from alternative energy sources and the fact that geothermal energy was essentially free adversely affected careful designs of plants which would maximize their performance for a given geothermal resource. There are, however, tremendous potentials to improve performance of many existing geothermal power plants by retrofitting, optimizing the operating conditions, re-selecting the most appropriate binary fluid in binary plants, and considering cogeneration such as a district heating and/or cooling system or a system to preheat water entering boilers in industrial facilities. In this dissertation, some representative geothermal resources and existing geothermal power plants in Nevada are investigated to show these potentials. Economic analysis of a typical geothermal resource shows that geothermal heating and cooling may generate up to 3 times as much revenue as power generation alone. A district heating/cooling system is designed for its incorporation into an existing 27 MW air-cooled binary geothermal power plant. The system as designed has the capability to meet the entire heating needs of an industrial park as well as 40% of its cooling needs, generating potential revenues of $14,040,000 per year. A study of the power plant shows that evaporative cooling can increase the power output by up to 29% in summer by decreasing the condenser temperature. The power output of the plant can be increased by 2.8 percent by optimizing the maximum pressure in the cycle. Also, replacing the existing working fluid isobutane by butane, R-114, isopentane, and pentane can increase the power output by up to 2.5 percent. Investigation of some well-known geothermal power generation technologies as alternatives to an existing 12.8 MW single-flash geothermal power plant shows that double-flash, binary, and combined flash/binary designs can increase the

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.

Drawing 1/100,000 scale geological map of Mt. Hakkoda geothermal district

Energy Technology Data Exchange (ETDEWEB)

Muraoka, Hirobumi; Takakura, Shin' ichi

1987-10-01

Geological map of geothermal district of Mt. Hakkoda was made which included the main volcanos created after Pliocene era. For the purpose, geothermal liquid, terrestial heat sources and its storing structures, were studied with consulting geological map. Aerial and satelite photographs were used for the study of faults, foldings, and dikes,. By the result, stratigragic order of layers, developing process of vocanos, and evoluting process of magma, were summarized for report. (5 figs, 4 tabs, 101 refs)

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

Non-electrical uses of geothermal energy

Energy Technology Data Exchange (ETDEWEB)

Barber E.; Fanelli, M.

1977-01-01

A comprehensive review covers the recognition of natural hot fluids in ancient times and their use for therapeutic baths; the first production of electricity from geothermal steam at Larderello, Italy, in 1904; the widespread geographical occurrence of geothermal fluids; exploration techniques; the extraction of geothermal fluids and their uses in spas, agriculture, aquaculture, domestic heating, and industrial applications; geothermal greenhouse heating world-wide; geothermal heating of animal and poultry houses, in culture of alligators and crocodiles (in Atagawa, Japan), and in fish culture; piping arrangements for district heating, and a tabulation of district heating installations world-wide; downhole exchanger systems used in Klamath Falls, Oregon, for domestic heating; industrial heating applications; and methods of disposal of geothermal fluids. Maps, diagrams, graphs, photographs, tables, and 48 references are included.

The transformative potential of geothermal heating in the U.S. energy market: A regional study of New York and Pennsylvania

International Nuclear Information System (INIS)

Reber, Timothy J.; Beckers, Koenraad F.; Tester, Jefferson W.

2014-01-01

Enhanced Geothermal Systems (EGS) could supply a significant fraction of the low-temperature (<125 °C) thermal energy used in the United States through Geothermal District Heating (GDH). In this study we develop a regional model to evaluate the potential for EGS district heating in the states of New York and Pennsylvania by simulating an EGS district heating network at each population center within the study region and estimating the levelized cost of heat (LCOH) from GDH for each community. LCOHs were then compiled into a supply curve from which several conclusions could be drawn. Our evaluation revealed that EGS district heating has the potential to supply cost-effective energy for space and water heating in several New York and Pennsylvania communities in the near future. To realize wider deployment, modest improvements in EGS technology, escalation of natural gas prices, and/or government incentives will likely be required to enable GDH to compete with other heating alternatives today. EGS reservoir flow rates, drilling costs, system lifetimes, and fluid return temperatures have significant effects on the LCOH of GDH and thus will provide the highest return on R and D investment, while creative implementation strategies can help EGS district heating overcome initial cost barriers that exist today. - Highlights: • EGS district heating potential evaluated for 2894 towns in New York and Pennsylvania. • Supply curves developed using estimated levelized cost of heat (LCOH) for each town. • Geothermal district heating has cost-saving potential in NY, PA and the US. • Initial candidate communities, R and D targets, and deployment strategies identified

Direct use of geothermal energy, Elko, Nevada district heating. Final report

Energy Technology Data Exchange (ETDEWEB)

Lattin, M.W.; Hoppe, R.D.

1983-06-01

In early 1978 the US Department of Energy, under its Project Opportunity Notice program, granted financial assistance for a project to demonstrate the direct use application of geothermal energy in Elko, Nevada. The project is to provide geothermal energy to three different types of users: a commercial office building, a commercial laundry and a hotel/casino complex, all located in downtown Elko. The project included assessment of the geothermal resource potential, resource exploration drilling, production well drilling, installation of an energy distribution system, spent fluid disposal facility, and connection of the end users buildings. The project was completed in November 1982 and the three end users were brought online in December 1982. Elko Heat Company has been providing continuous service since this time.

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.

Geothermal space/water heating for Mammoth Lakes Village, California. Quarterly technical progress report, 13 December 1976-12 March 1977

Energy Technology Data Exchange (ETDEWEB)

Sims, A.V.; Racine, W.C.

1977-01-01

During the second three months of this feasibility study to determine the technical, economic and environmental feasibility of heating Mammoth Lakes Village, California using geothermal energy, the following work was accomplished. A saturation survey of the number and types of space and water heaters currently in use in the Village was completed. Electric energy and ambient temperature metering equipment was installed. Peak heating demand for Mammoth Lakes was estimated for the years 1985, 1990 and 2000. Buildings were selected which are considered typical of Mammoth Lakes in terms of their heating systems to be used in estimating the cost of installing hydronic heating systems in Mammoth. Block diagrams and an order of magnitude cost comparison were prepared for high-temperature and low-temperature geothermal district heating systems. Models depicting a geothermal district heating system and a geothermal-electric power plant were designed, built and delivered to ERDA in Washington. Local input to the feasibility study was obtained from representatives of the State of California Departments of Transportation and Fish and Game, US Forest Service, and Mono County Planning Department.

Heat planning for fossil-fuel-free district heating areas with extensive end-use heat savings

DEFF Research Database (Denmark)

Harrestrup, Maria; Svendsen, S.

2014-01-01

is a theoretical investigation of the district heating system in the Copenhagen area, in which heat conservation is related to the heat supply in buildings from an economic perspective. Supplying the existing building stock from low-temperature energy resources, e.g. geothermal heat, might lead to oversized......The Danish government plans to make the Danish energy system to be completely free of fossil fuels by 2050 and that by 2035 the energy supply for buildings and electricity should be entirely based on renewable energy sources. To become independent from fossil fuels, it is necessary to reduce...... the energy consumption of the existing building stock, increase energy efficiency, and convert the present heat supply from fossil fuels to renewable energy sources. District heating is a sustainable way of providing space heating and domestic hot water to buildings in densely populated areas. This paper...

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].

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...

Geothermal direct-heat utilization assistance. Federal Assistance Program quarterly project progress report, April 1--June 30, 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

This report summarizes geothermal technical assistance, R and D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the third quarter of FY98 (April--June, 1998). It describes 231 contacts with parties during this period related to technical assistance with geothermal direct heat projects. Areas dealt with included requests for general information including material for high school and university students, and material on geothermal heat pumps, resource and well data, spacing heating and cooling, greenhouses, aquaculture, equipment, district heating, resorts and spas, industrial applications, snow melting and electric power. Research activities include work on model construction specifications for line shaft submersible pumps and plate heat exchangers, and a comprehensive aquaculture developers package. A brochure on Geothermal Energy in Klamath County was developed for state and local tourism use. Outreach activities include the publication of the Quarterly Bulletin (Vol. 19, No. 2) with articles on research at the Geo-Heat Center, sustainability of geothermal resources, injection well drilling in Boise, ID and a greenhouse project in the Azores. Other outreach activities include dissemination of information mainly through mailings of publications, tours of local geothermal uses, geothermal library acquisitions and use, participation in workshops, short courses and technical meetings by the staff, and progress monitor reports on geothermal activities.

Geothermal heat-pump systems of heat supply

International Nuclear Information System (INIS)

Vasil'ev, G.P.

2004-01-01

The data on the multilayer operation of the objects, located in the climatic conditions of the central area of Russia and equipped with the geothermal heat-pumping systems of the heat supply are presented. The results of the analytical studies on evaluating the geothermal heat-pumping systems of the heat supply integration efficiency into the structure of the energy supply system, prevailing in the country, are presented [ru

Evaluation of Excess Heat Utilization in District Heating Systems by Implementing Levelized Cost of Excess Heat

Directory of Open Access Journals (Sweden)

Borna Doračić

2018-03-01

Full Text Available District heating plays a key role in achieving high primary energy savings and the reduction of the overall environmental impact of the energy sector. This was recently recognized by the European Commission, which emphasizes the importance of these systems, especially when integrated with renewable energy sources, like solar, biomass, geothermal, etc. On the other hand, high amounts of heat are currently being wasted in the industry sector, which causes low energy efficiency of these processes. This excess heat can be utilized and transported to the final customer by a distribution network. The main goal of this research was to calculate the potential for excess heat utilization in district heating systems by implementing the levelized cost of excess heat method. Additionally, this paper proves the economic and environmental benefits of switching from individual heating solutions to a district heating system. This was done by using the QGIS software. The variation of different relevant parameters was taken into account in the sensitivity analysis. Therefore, the final result was the determination of the maximum potential distance of the excess heat source from the demand, for different available heat supplies, costs of pipes, and excess heat prices.

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.

Heat planning for fossil-fuel-free district heating areas with extensive end-use heat savings: A case study of the Copenhagen district heating area in Denmark

International Nuclear Information System (INIS)

Harrestrup, M.; Svendsen, S.

2014-01-01

The Danish government plans to make the Danish energy system to be completely free of fossil fuels by 2050 and that by 2035 the energy supply for buildings and electricity should be entirely based on renewable energy sources. To become independent from fossil fuels, it is necessary to reduce the energy consumption of the existing building stock, increase energy efficiency, and convert the present heat supply from fossil fuels to renewable energy sources. District heating is a sustainable way of providing space heating and domestic hot water to buildings in densely populated areas. This paper is a theoretical investigation of the district heating system in the Copenhagen area, in which heat conservation is related to the heat supply in buildings from an economic perspective. Supplying the existing building stock from low-temperature energy resources, e.g. geothermal heat, might lead to oversized heating plants that are too expensive to build in comparison with the potential energy savings in buildings. Long-term strategies for the existing building stock must ensure that costs are minimized and that investments in energy savings and new heating capacity are optimized and carried out at the right time. - Highlights: • We investigate how much heating consumption needs to be reduced in a district heating area. • We examine fossil-fuel-free supply vs. energy conservations in the building stock. • It is slightly cost-beneficial to invest in energy renovation from today for a societal point of view. • It is economically beneficial for district heating companies to invest in energy renovations from today. • The cost per delivered heat unit is lower when energy renovations are carried out from today

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.

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.

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.)

Geothermal Direct Heat Applications Program Summary

Energy Technology Data Exchange (ETDEWEB)

None

1981-09-25

Because of the undefined risk in the development and use of geothermal energy as a thermal energy source, the Department of Energy Division of Geothermal Energy solicited competitive proposals for field experiments in the direct use of geothermal energy. Twenty-two proposals were selected for cost-shared funding with one additional project co-funded by the State of New Mexico. As expected, the critical parameter was developing a viable resource. So far, of the twenty resources drilled, fourteen have proved to be useful resources. These are: Boise, Idaho; Elko heating Company in Nevada; Pagosa Springs, Colorado; Philip School, Philip, South Dakota; St. Mary's Hospital, Pierre, South Dakota; Utah Roses near Salt Lake City; Utah State Prison, Utah; Warm Springs State Hospital, Montana; T-H-S Hospital, Marlin, Texas; Aquafarms International in the Cochella Valley, California; Klamath County YMCA and Klamath Falls in Oregon; Susanville, California and Monroe, utah. Monroe's 164 F and 600 gpm peak flow was inadequate for the planned project, but is expected to be used in a private development. Three wells encountered a resource insufficient for an economical project. These were Madison County at Rexburg, Idaho; Ore-Ida Foods at Ontario, Oregon and Holly Sugar at Brawley, California. Three projects have yet to confirm their resource. The Navarro College well in Corsicana, Texas is being tested; the Reno, Moana, Nevada well is being drilled and the El Centro, California well is scheduled to be drilled in January 1982. The agribusiness project at Kelly Hot Springs was terminated because a significant archeological find was encountered at the proposed site. The Diamond Ring Ranch in South Dakota, and the additional project, Carrie Tingley Hospital in Truth or Consequences, New Mexico both used existing wells. The projects that encountered viable resources have proceeded to design, construct, and in the most advanced projects, to operate geothermal systems for

Optimization of a local district heating plant under fuel flexibility and performance

DEFF Research Database (Denmark)

Rudra, Souman; Rosendahl, Lasse; From, Niels

2011-01-01

are calculated for various local fuels in energyPRO. A comparison has been made between the reference model and the basis for individual solutions. The greatest reduction in heat price is obtained by replacing one engine with a new biogas where heat production is divided by 66% of biogas, 13% natural gas engines......, an investigation has been made to reduce the use of fossil fuels for district heating system and make use of the local renewable resources (Biogas, Solar and Geothermal) for district heating purpose. In this article, the techno-economic assessment is achieved through the development of a suite of models...

Exploration of the enhanced geothermal system (EGS) potential of crystalline rocks for district heating (Elbe Zone, Saxony, Germany)

Science.gov (United States)

Förster, Andrea; Förster, Hans-Jürgen; Krentz, Ottomar

2018-01-01

This paper addresses aspects of a baseline geothermal exploration of the thermally quiescent Elbe Zone (hosting the cities of Meissen and Dresden) for a potential deployment of geothermal heat in municipal heating systems. Low-permeable to impermeable igneous and metamorphic rocks constitute the major rock types at depth, implying that an enhanced geothermal system needs to be developed by creating artificial flow paths for fluids to enhance the heat extraction from the subsurface. The study includes the development of geological models for two areas on the basis of which temperature models are generated at upper crustal scale. The models are parameterized with laboratory-measured rock thermal properties (thermal conductivity k, radiogenic heat production H). The uncertainties of modelled temperature caused by observed variations of k and H and inferred mantle heat flow are assessed. The study delineates highest temperatures within the intermediate (monzonite/syenite unit) and mafic rocks (diorite/monzodiorite unit) forming the deeper portions of the Meissen Massif and, specifically for the Dresden area, also within the low-metamorphic rocks (slates/phyllites/quartzites) of the Elbtalschiefergebirge. Boreholes 3-4 km deep need to be drilled to reach the envisioned economically favourable temperatures of 120 °C. The metamorphic and mafic rocks exhibit low concentrations of U and Th, thus being advantageous for a geothermal use. For the monzonite/syenite unit of high heat production ( 6 µW m-3) in the Meissen Massif, the mobilization of Th and U into the geothermal working fluid is assumed to be minor, although their various radioactive decay products will be omnipresent during geothermal use.

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

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

Prenzlau geothermal heat exchanger - technical concept and performance; Erdwaermetiefensonde Prenzlau - technisches Konzept und Betriebserfahrungen

Energy Technology Data Exchange (ETDEWEB)

Schneider, D [KEMA-IEV GmbH, Dresden (Germany); Brossmann, E; Wetzel, H [VEAG Berlin (Germany)

1997-12-01

The geothermal heat exchanger transfers heat geothermal heat through the metal wall of the outer pipe to the circulating water. The clean water heats up on its way down and is then pumped up again through the insulated inner riser pipe. The heated water is used for district heating. Drilling started on 26 March 1994, and the system was commissioned on 10 November 1994. Today, it supplies heat and warm water to about 1100 apartments. During its first year of operation the Prenzlau geothermal heat exchanger, which is 2800 m deep, covered more than 20 % of the heat demand of the Prenzlau-West district heating grid. The seasonal performance factor in continuous operation of the 500 kW system is between 8 and 12 % of the weather-dependent peak load, with hourly peaks of more than 700 kW. (orig./AKF) [Deutsch] Die Erdwaermetiefensonde nutzt die Waermeuebertragung vom warmen Erdreich durch die Metallwand des Aussenrohrs zum darin zirkulierenden Wasser. Das eingeleitete saubere Wasser erwaermt sich an der aeusseren Rohrwandung auf dem Weg nach unten und wird dann im inneren waermeisolierten Steigrohr an die Oberflaeche befoerdert. Das erwaermte Waser wird in Prenzlau ueber eine Waermepumpe zu Fernwaermezwecken benutzt. Am 26.3.1994 begannen die Bohrarbeiten, und am 10.11.1994 ging die gesamte Anlage in Betrieb, die heute ca. 1100 Wohnungen mit Waerme und Warmwasser versorgt. Die Erdwaermetiefensonde Prenzlau mit einer Tiefe von 2800 m deckte in den ersten beiden Betriebsjahren ueber 20 % des Waermebedarfs des Fernwaermenetzes Prenzlau-West. Die Jahresdauerleistung der Erdwaermetiefensonde mit 500 kW liegt bei 8-12 % der witterungsbedingten Jahreshoechstlast. Die Sonde gestattet Spitzenleistungen im Stundenbereich von mehr als 700 kW. (orig./AKF)

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

Conceptual design study of geothermal district heating of a thirty-house subdivision in Elko, Nevada, using existing water-distribution systems, Phase III. Final technical report, October 1, 1979-September 30, 1980

Energy Technology Data Exchange (ETDEWEB)

Pitts, D.R.

1980-09-30

A conceptual design study for district heating of a 30-home subdivision located near the southeast extremity of the city of Elko, Nevada is presented. While a specific residential community was used in the study, the overall approach and methodologies are believed to be generally applicable for a large number of communities where low temperature geothermal fluid is available. The proposed district heating system utilizes moderate temperature, clean domestic water and existing community culinary water supply lines. The culinary water supply is heated by a moderate temperature geothermal source using a single heat exchanger at entry to the subdivision. The heated culinary water is then pumped to the houses in the community where energy is extracted by means of a water supplied heat pump. The use of heat pumps at the individual houses allows economic heating to result from supply of relatively cool water to the community, and this precludes the necessity of supplying objectionably hot water for normal household consumption use. Each heat pump unit is isolated from the consumptive water flow such that contamination of the water supply is avoided. The community water delivery system is modified to allow recirculation within the community, and very little rework of existing water lines is required. The entire system coefficient of performance (COP) for a typical year of heating is 3.36, exclusive of well pumping energy.

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.

Geothermal energy, what technologies for what purposes?

International Nuclear Information System (INIS)

2008-01-01

This book, fully illustrated and rich of concrete examples, takes stock of the different technologies implemented today to use the Earth's heat: geothermal heat pumps for domestic, tertiary and collective residential uses, geothermal district heating networks and geothermal power plants for power generation. This overview is completed by a description of the future perspectives offered by this renewable energy source in the World and in France in terms of energy independence and technological innovation: geo-cooling, hybrid systems, absorption heat pumps or stimulated geothermal systems. (J.S.)

A case study of radial jetting technology for enhancing geothermal energy systems at Klaipeda geothermal demonstration plant

NARCIS (Netherlands)

Nair, R.; Peters, E.; Sliaupa, S.; Valickas, R.; Petrauskas, S.

2017-01-01

In 1996 a geothermal energy project was initiated at Klaipėda, Lithuania, to demonstrate the feasibility of using low enthalpy geothermal water as a renewable energy resource in district heating systems. The Klaipėda geothermal plant is situated within the West Lithuanian geothermal anomaly with a

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.

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.

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

Geochemical implications of production and storage control by coupling a direct-use geothermal system with heat networks

NARCIS (Netherlands)

Daniilidis, Alexandros; Scholten, Tjardo; Hooghiem, Joram; Persis, Claudio De; Herber, Rien

2017-01-01

This paper outlines a method in which the heat production of a geothermal system is controlled in relation to the demand from a district-heating network. A model predictive control strategy is designed, which uses volume measurements in the storage tank, and predictions of the demand, to regulate

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.)

District heating as the infrastructure for competition among fuels and technologies

DEFF Research Database (Denmark)

Grohnheit, Poul Erik; Mortensen, Bent Ole Gram

2016-01-01

for increased energy efficiency. Additional technologies suitable for small-scale networks are heat pumps, solar panels and local biomass in the form of straw or biogas. For large-scale urban networks, incineration of urban waste and geothermal heat are key technologies. With heat storages district heating...... infrastructure can contribute significantly to balancing the intermittency of wind power. This paper is an update of the authors' article published in Energy Policy in 2003 focusing on the European directives focusing on competition in the electricity and gas network industries and promotion of renewables...... and cogeneration but limited support for the development and expansion of the district heating infrastructure. It was partly based on a contribution to the Shared Analysis Project for the European Commission Directorate-General for Energy, concerning the penetration of combined heat and power (CHP), energy saving...

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

Geothermal heating, diapycnal mixing and the abyssal circulation

Directory of Open Access Journals (Sweden)

J. Emile-Geay

2009-06-01

Full Text Available The dynamical role of geothermal heating in abyssal circulation is reconsidered using three independent arguments. First, we show that a uniform geothermal heat flux close to the observed average (86.4 mW m⁻² supplies as much heat to near-bottom water as a diapycnal mixing rate of ~10⁻⁴ m² s⁻¹ – the canonical value thought to be responsible for the magnitude of the present-day abyssal circulation. This parity raises the possibility that geothermal heating could have a dynamical impact of the same order. Second, we estimate the magnitude of geothermally-induced circulation with the density-binning method (Walin, 1982, applied to the observed thermohaline structure of Levitus (1998. The method also allows to investigate the effect of realistic spatial variations of the flux obtained from heatflow measurements and classical theories of lithospheric cooling. It is found that a uniform heatflow forces a transformation of ~6 Sv at σ₄=45.90, which is of the same order as current best estimates of AABW circulation. This transformation can be thought of as the geothermal circulation in the absence of mixing and is very similar for a realistic heatflow, albeit shifted towards slightly lighter density classes. Third, we use a general ocean circulation model in global configuration to perform three sets of experiments: (1 a thermally homogenous abyssal ocean with and without uniform geothermal heating; (2 a more stratified abyssal ocean subject to (i no geothermal heating, (ii a constant heat flux of 86.4 mW m⁻², (iii a realistic, spatially varying heat flux of identical global average; (3 experiments (i and (iii with enhanced vertical mixing at depth. Geothermal heating and diapycnal mixing are found to interact non-linearly through the density field, with geothermal heating eroding the deep stratification supporting a downward diffusive flux, while diapycnal mixing acts to map

Utilization of geothermal energy in the USSR

International Nuclear Information System (INIS)

Kononov, V.I.; Dvorov, I.M.

1990-01-01

This paper reports that at present geothermal energy is utilized in the USSR mostly for district heating, and for industrial and agricultural purposes. The populations of 7 towns have district heating that is supplied by thermal waters. The population supplied totals about 125,000 people. The total area of greenhouses is 850,000 m 2 . Electric energy generated at geothermal power stations still remains negligible with the installed capacity of the single Pauzhetka station (Kamchatka) being 11 MW. another station at Mutnovka is currently under construction and is expected to be producing 50 MW by 1992 and 200 MW by 1998. The proven geothermal resources in the USSR provide hope for a significant increase in the utilization of the earth's deep heat in the near future

Geothermal heat potential - the source for heating greenhouses in Southestern Europe

Directory of Open Access Journals (Sweden)

Urbancl Danijela

2016-01-01

Full Text Available The paper presents economically evaluated solutions for heating greenhouses with geothermal potential, if the same greenhouse is placed in two different locations in Southeastern Europe, one in Slovenia and the other in Serbia. The direct geothermal water exploitation using heat exchangers is presented and the remaining heat potential of already used geothermal water is exploited using high temperature heat pumps. Energy demands for heating greenhouses are calculated considering climatic parameters of both locations. Furthermore, different constructions materials are taken into account, and energy demands are evaluated if the same greenhouse is made of 4 mm toughened single glass, double insulated glass or polycarbonate plates. The results show that the geothermal energy usage is economically feasible in both locations, because payback periods are in range from two to almost eight years for different scenarios.

Efficient district heating in the future energy system. Final report; Effektiv fjernvarme i fremtidens energisystem. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

2009-07-01

The purpose of this project is to illustrate how district heating can develop its role in the future Danish energy system, for example by reducing energy losses and the dynamic use of common technologies such as cogeneration and heat storage, and less widespread technologies such as heat pumps, geothermal heating, and cooling. The aim is also to analyse how electricity and district heating can interact more effectively, and to point out how framework conditions are important for district heating's continued development and efficiency. In the project, a linear optimization model is developed and applied as to analyse the interaction between district heating supply on the one hand, and energy savings, CO{sub 2} targets, wind power and the international electricity market on the other hand. Furthermore, more close-case operational analyses of district heating systems have been made in Ringkoebing and the metropolitan area, based on data from the district heating companies. Finally, a wide range of challenges for district heating in the long term were discussed and analysed during meetings with the project's reference group, including the need for development and demonstration projects. (ln)

Low Temperature District Heating for Future Energy Systems

DEFF Research Database (Denmark)

Schmidt, Dietrich; Kallert, Anna; Blesl, Markus

2017-01-01

of the building stock. Low temperature district heating (LTDH) can contribute significantly to a more efficient use of energy resources as well as better integration of renewable energy (e.g. geothermal or solar heat), and surplus heat (e.g. industrial waste heat) into the heating sector. LTDH offers prospects......The building sector is responsible for more than one third of the final energy consumption of societies and produces the largest amount of greenhouse gas emissions of all sectors. This is due to the utilisation of combustion processes of mainly fossil fuels to satisfy the heating demand...... for both the demand side (community building structure) and the supply side (network properties or energy sources). Especially in connection with buildings that demand only low temperatures for space heating. The utilisation of lower temperatures reduces losses in pipelines and can increase the overall...

Geothermal direct-heat utilization assistance. Quarterly report, October--December 1996

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

This 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-97. It describes 174 contracts 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, economics and resources. Research activities are summarized on greenhouse peaking. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

Direct Heat

Energy Technology Data Exchange (ETDEWEB)

Lienau, P J

1990-01-01

Potential resources and applications of earth heat in the form of geothermal energy are large. United States direct uses amount to 2,100 MWt thermal and worldwide 8,850 MWt above a reference temperature of 35 degrees Celsius. Space and district heating are the major direct uses of geothermal energy. Equipment employed in direct use projects is of standard manufacture and includes downhole and circulation pumps, transmission and distribution pipelines, heat exchangers and convectors, heat pumps and chillers. Direct uses of earth heat discussed are space and district heating, greenhouse heating and fish farming, process and industrial applications. The economic feasibility of direct use projects is governed by site specific factors such as location of user and resource, resource quality, system load factor and load density, as well as financing. Examples are presented of district heating in Klamath Falls, and Elko. Further developments of direct uses of geothermal energy will depend on matching user needs to the resource, and improving load factors and load density.

Heat flow, heat transfer and lithosphere rheology in geothermal areas: Features and examples

Science.gov (United States)

Ranalli, G.; Rybach, L.

2005-10-01

Surface heat flow measurements over active geothermal systems indicate strongly positive thermal anomalies. Whereas in "normal" geothermal settings, the surface heat flow is usually below 100-120 mW m - 2 , in active geothermal areas heat flow values as high as several watts per meter squared can be found. Systematic interpretation of heat flow patterns sheds light on heat transfer mechanisms at depth on different lateral, depth and time scales. Borehole temperature profiles in active geothermal areas show various signs of subsurface fluid movement, depending on position in the active system. The heat transfer regime is dominated by heat advection (mainly free convection). The onset of free convection depends on various factors, such as permeability, temperature gradient and fluid properties. The features of heat transfer are different for single or two-phase flow. Characteristic heat flow and heat transfer features in active geothermal systems are demonstrated by examples from Iceland, Italy, New Zealand and the USA. Two main factors affect the rheology of the lithosphere in active geothermal areas: steep temperature gradients and high pore fluid pressures. Combined with lithology and structure, these factors result in a rheological zonation with important consequences both for geodynamic processes and for the exploitation of geothermal energy. As a consequence of anomalously high temperature, the mechanical lithosphere is thin and its total strength can be reduced by almost one order of magnitude with respect to the average strength of continental lithosphere of comparable age and thickness. The top of the brittle/ductile transition is located within the upper crust at depths less than 10 km, acts as the root zone of listric normal faults in extensional environments and, at least in some cases, is visible on seismic reflection lines. These structural and rheological features are well illustrated in the Larderello geothermal field in Tuscany.

Geothermal concept for energy efficient improvement of space heating and cooling in highly urbanized area

Directory of Open Access Journals (Sweden)

Vranjes Ana

2015-01-01

Full Text Available New Belgrade is a highly urbanized commercial and residential district of Belgrade lying on the alluvial plane of the Sava and the Danube rivers. The groundwater of the area is a geothermal resource that is usable through geothermal heat pumps (GHP. The research has shown that the “heat island effect” affects part of the alluvial groundwater with the average groundwater temperature of about 15.5°C, i.e. 2°C higher than the one in less urbanized surroundings. Based on the measured groundwater temperatures as well as the appraisal of the sustainable aquifer yield, the available thermal power of the resource is estimated to about 29MWt. The increasing urbanization trend of the New Belgrade district implies the growing energy demands that may partly be met by the available groundwater thermal power. Taking into consideration the average apartment consumption of 80 Wm-2, it is possible to heat about 360,000 m2 and with the consumption efficiency of 50 Wm-2, it would be possible to heat over 570,000 m2. Environmental and financial aspects were considered through the substitution of conventional fuels and the reduction of greenhouse gas emission as well as through the optimization of the resource use.

District heating in Switzerland

International Nuclear Information System (INIS)

Herzog, F.

1991-01-01

District heating has been used in Switzerland for more than 50 years. Its share of the heat market is less than 3% today. An analysis of the use of district heating in various European countries shows that a high share of district heating in the heat market is always dependent on ideal conditions for its use. Market prospects and possible future developments in the use of district heating in Switzerland are described in this paper. The main Swiss producers and distributors of district heating are members of the Association of District Heating Producers and Distributors. This association supports the installation of district heating facilities where ecological, energetical and economic aspects indicate that district heating would be a good solution. (author) 2 tabs., 6 refs

Road map for district heating. The role of district heating in the energy system. Main report; Denmark; Roadmap for fjernvarmen. Fjernvarmens rolle i energisystemet. Hovedrapport

Energy Technology Data Exchange (ETDEWEB)

Hofmeister, M.; Aabye Moeller, A.; Eggert, A.; Bjerregaard, M. (Fjernvarmens Udviklingscenter, AArhus (Denmark)); Dyrelund, A. (Ramboell, Koebenhavn (Denmark)); OErsted Pedersen, H. (Ea Energianalyse, Koebenhavn (Denmark)); Lund, H. (Aalborg Univ., Aalborg (Denmark))

2011-07-01

In the recent years many studies of how Denmark can be fossil free by 2050 it is agreed that district heating will play a crucial role. District heating is an important factor of phasing out fossil fuels in an energy-and cost-effective way. But the future energy supply without fossil fuels poses new requirements for district heating. In the future, district heating shall provide energy for low-energy houses, have low distribution losses and use a variety of heat sources such as geothermal, solar, waste, surplus heat, CHP and various biomass con-version processes. In addition, it must all be done in an energy efficient way and in an active interaction with production of electricity and electricity consumption and, through integration of electricity from wind, solar and wave power. Low temperature, use of heat pumps and the interaction with electricity and biomass will be keywords. It is not only in Denmark we will need an active development of future technologies and systems. Large parts of Europe and many other parts of the world need the same development, and today Denmark has a significant export in the market - an export that has risen sharply, despite the recent economic recession. There is thus a double need to actively promote the development of future district heating technologies. We will partly need the technology development to realize the goal of a fossil free society and secondly because it is necessary to maintain and expand the export. This report contains a number of proposals for concrete actions - a roadmap for the development of district heating. The project is anchored at the District Energy Development Center that will work for an implementation of the concrete project ideas after the project completion. There is a need to increase the activity level for development of district heating. There is therefore a need to ensure financing of this development. We suggest that this can be done by creating an opportunity for a more sustained funding, for

Road map for district heating. The role of district heating in the energy system. Summary report; Denmark; Roadmap for fjernvarmen. Fjernvarmens rolle i energisystemet. Resumerapport

Energy Technology Data Exchange (ETDEWEB)

Hofmeister, M.; Aabye Moeller, A.; Eggert, A.; Bjerregaard, M. (Fjernvarmens Udviklingscenter, AArhus (Denmark)); Dyrelund, A. (Ramboell, Koebenhavn (Denmark)); OErsted Pedersen, H. (Ea Energianalyse, Koebenhavn (Denmark)); Lund, H. (Aalborg Univ., Aalborg (Denmark))

2011-07-01

In the recent years many studies of how Denmark can be fossil free by 2050 it is agreed that district heating will play a crucial role. District heating is an important factor of phasing out fossil fuels in an energy-and cost-effective way. But the future energy supply without fossil fuels poses new requirements for district heating. In the future, district heating shall provide energy for low-energy houses, have low distribution losses and use a variety of heat sources such as geothermal, solar, waste, surplus heat, CHP and various biomass con-version processes. In addition, it must all be done in an energy efficient way and in an active interaction with production of electricity and electricity consumption and, through integration of electricity from wind, solar and wave power. Low temperature, use of heat pumps and the interaction with electricity and biomass will be keywords. It is not only in Denmark we will need an active development of future technologies and systems. Large parts of Europe and many other parts of the world need the same development, and today Denmark has a significant export in the market - an export that has risen sharply, despite the recent economic recession. There is thus a double need to actively promote the development of future district heating technologies. We will partly need the technology development to realize the goal of a fossil free society and secondly because it is necessary to maintain and expand the export. This report contains a number of proposals for concrete actions - a roadmap for the development of district heating. The project is anchored at the District Energy Development Center that will work for an implementation of the concrete project ideas after the project completion. There is a need to increase the activity level for development of district heating. There is therefore a need to ensure financing of this development. We suggest that this can be done by creating an opportunity for a more sustained funding, for

A multicriteria approach to evaluate district heating system options

Energy Technology Data Exchange (ETDEWEB)

Ghafghazi, S.; Sowlati, T. [Department of Wood Science, University of British Columbia, 2931-2424 Main Mall, Vancouver, BC (Canada); Sokhansanj, S. [Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC (Canada); Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Melin, S. [Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC (Canada); Delta Research Corporation, Delta, BC (Canada)

2010-04-15

District energy systems, in which renewable energy sources may be utilized, are centralized systems to provide energy to residential and commercial buildings. The aim of this paper is to evaluate and rank energy sources available for a case of district heating system in Vancouver, Canada, based on multiple criteria and the view points of different stakeholders, and to show how communication would affect the ranking of alternatives. The available energy sources are natural gas, biomass (wood pellets), sewer heat, and geothermal heat. The evaluation criteria include GHG emissions, particulate matter emissions, maturity of technology, traffic load, and local source. In order to rank the energy options the PROMETHEE method is used. In this paper, two different scenarios were developed to indicate how the communication between the stakeholders would affect their preferences about criteria weights and would change the ranking of alternatives. The result of this study shows that without communication the best energy source for the considered district energy system is different for different stakeholders. While, addressing concerns through efficient communication would result in a general consensus. In this case, wood pellet is the best energy alternative for all the stakeholders. (author)

Leverkusen revenue office building with geothermal and district heating; Finanzamt Leverkusen setzt auf Geothermie und Fernwaerme

Energy Technology Data Exchange (ETDEWEB)

Keveloh, Holger [Depenbrock Systembau GmbH und Co. KG, Bielefeld (Germany); Paterak, Anette; Wiemer, Bianca; Foerschler, Eberhard [Assmann Beraten+Planen GmbH, Dortmund (Germany)

2011-07-01

Efficient air conditioning of office buildings is possible with concrete core activation via a geothermal heat pump. The new building of the revenue office at Leverkusen will use this technology. (orig.)

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.

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

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.

Geothermal energy utilization and technology

CERN Document Server

Dickson, Mary H; Fanelli, Mario

2013-01-01

Geothermal energy refers to the heat contained within the Earth that generates geological phenomena on a planetary scale. Today, this term is often associated with man's efforts to tap into this vast energy source. Geothermal Energy: utilization and technology is a detailed reference text, describing the various methods and technologies used to exploit the earth's heat. Beginning with an overview of geothermal energy and the state of the art, leading international experts in the field cover the main applications of geothermal energy, including: electricity generation space and district heating space cooling greenhouse heating aquaculture industrial applications The final third of the book focuses upon environmental impact and economic, financial and legal considerations, providing a comprehensive review of these topics. Each chapter is written by a different author, but to a set style, beginning with aims and objectives and ending with references, self-assessment questions and answers. Case studies are includ...

The chemistry and isotopic composition of waters in the low-enthalpy geothermal system of Cimino-Vico Volcanic District, Italy

DEFF Research Database (Denmark)

Battistel, Maria; Hurwitz, Shaul; Evans, William C.

2016-01-01

Geothermal energy exploration is based in part on interpretation of the chemistry, temperature, and discharge rate of thermal springs. Here we present the major element chemistry and the δD, δ18O, 87Sr/86Sr and δ11B isotopic ratio of groundwater from the low-enthalpy geothermal system near the city...... and tortuous ascent enhances extraction of boron but also promotes conductive cooling, partially masking the heat present in the reservoir. Overall data from this study is consistent with previous studies that concluded that the geothermal system has a large energy potential....... of Viterbo in the Cimino-Vico volcanic district of west-Central Italy. The geothermal system hosts many thermal springs and gas vents, but the resource is still unexploited. Water chemistry is controlled by mixing between low salinity,HCO3-rich fresh waters (

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

Experiments Demonstrate Geothermal Heating Process

Science.gov (United States)

Roman, Harry T.

2012-01-01

When engineers design heat-pump-based geothermal heating systems for homes and other buildings, they can use coil loops buried around the perimeter of the structure to gather low-grade heat from the earth. As an alternative approach, they can drill well casings and store the summer's heat deep in the earth, then bring it back in the winter to warm…

Necessity for usage of geothermal heat pump

International Nuclear Information System (INIS)

Dimitrov, Konstantin; Armenski, Slave; Gacevski, Marijan

2004-01-01

Every day we are witnesses of constantly rapid increase of consumption of Electric energy in R. of Macedonia as so as in the other countries in all the world. This rapid increase of consumption of Electric energy independent of a lot of electrical units, which are applying in human life like: homes, administration and publication objects, as well as in industry. All of this conditions make us to thinking how is possible more rational consumption of electric energy in all areas in human life. One of the possible manners to reduce the consumption of electrical energy for heating and cooling is to use geothermal heat pumps. In this paper will be proposed geothermal heat pump, which is going to use the heat of earth by vertical and horizontal cupper pipe heat exchanger with data from-GHP (Geothermal Heat Pump) NORDIC, factory in Canada. Also, it will be examined all parameters and done comparison with already existing ones. It is analyzed comparison of GHP with other energy units and what it means for rational consumption of electric energy, economic saving and ecology saving. (Author)

Geothermal energy: the earth, source of heat and electric power

International Nuclear Information System (INIS)

Lenoir, D.

2005-01-01

This document provides information on the geothermal energy. It presents the different types of geothermal deposits (very low, low and medium energy geothermal energy), the french deposits and the heat production. The electric power production from the geothermal energy is also discussed with the example of Soultz-sous-Forets. The last part deals with the heat pumps. (A.L.B.)

Wind power integration in Aalborg Municipality using compression heat pumps and geothermal absorption heat pumps

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

2013-01-01

-temperature geothermal resources. The analyses have also demonstrated that the municipality will still rely heavily on surrounding areas for electric load balancing assistance. With a departure in a previously elaborated 100% renewable energy scenario, this article investigates how absorption heat pumps (AHP......Aalborg Municipality, Denmark is investigating ways of switching to 100% renewable energy supply over the next 40 years. Analyses so far have demonstrated a potential for such a transition through energy savings, district heating (DH) and the use of locally available biomass, wind power and low......) and compression heat pumps (HP) for the supply of DH impact the integration of wind power. Hourly scenario-analyses made using the EnergyPLAN model reveal a boiler production and electricity excess which is higher with AHPs than with HPs whereas condensing mode power generation is increased by the application...

2012 geothermal energy congress. Proceedings

International Nuclear Information System (INIS)

2012-01-01

Within the Geothermal Energy Congress 2012 from 13th to 16th November 2012, in Karlsruhe (Federal Republic of Germany), the following lectures were held: (1) Comparison of different methods for the design of geothermal probes on the example of the thermal utilization of smouldering fires at heaps (Sylvia Kuerten); (2) Determination of the thermo-physical features of loose rocks (Johannes Stegner); (3) Tools for the planning and operation of district heating grids (Werner Seichter); (4) geo:build - System optimisation of the cooling mode of the ground-source heat and cooling supply (Franziska Bockelmann); (5) Successful and economic conception, planning and optimization of district heating grids (Werner Seichter); (6) Treacer / Heat transfer decoupling in a heterogeneous hydrothermal reservoir characterized by geological faults in the Upper Rhine Graben (I. Ghergut); (7) Determination of the porosity, thermal conductivity and particle size distribution in selected sections of the Meisenheim-1 drilling core (Saar-Nahe basin, Rheinland-Palatinate) under consideration of geothermally relevant formulation of questions (Gillian Inderwies); (8) Innovative technologies of exploration in the Jemez Geothermal project, New Mexico, USA (Michael Albrecht); (9) Geothermal energy, heat pump and TABS - optimization of planning, operational control and control (Franziska Bockelmann); (10) The impact of large-scale geothermal probes (storage probes) on the heat transfer and heat loss (Christopher Steins); (11) Numeric modelling of the permocarbon in the northern Upper Rhine Graben (L. Dohrer); (12) Engineering measurement solutions on quality assurance in the exploitation of geothermal fields (C. Lehr); (13) Evaluation and optimization of official buildings with the near-surface geothermal energy for heating and cooling (Franziska Bockelmann); (14) On-site filtration for a rapid and cost-effective quantification of the particle loading in the thermal water stream (Johannes Birner

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

In the Loop : A look at Manitoba's geothermal heat pump industry

International Nuclear Information System (INIS)

2002-03-01

This booklet outlines the position of Manitoba's heat pump market with the objective of promoting the widespread use of geothermal heat pumps in the province. It makes reference to the size of the market, customer satisfaction with heat pumps, and opinion of key players in the industry regarding the heat pump market. The information in this booklet is drawn on market research and lessons learned in Europe and the United States. In October 2001, a group of key stakeholders in Manitoba's heat pump market attended an industry working meeting to address the issues of market barriers, market enablers and market hot buttons. Market barriers include the high cost of geothermal heat pumps, lack of consumer awareness, lack of consistent standards, and public perception that heat pumps are not reliable. Market enablers include the low and stable operating costs of geothermal heat pumps, high level of comfort, high quality and reliability of geothermal heat pumps, and financial incentives under Manitoba Hydro's Power Smart Commercial Construction Program. Market hot buttons include lowering the cost of geothermal heat pumps, improving industry performance, increasing consumer awareness, and forming a Manitoba Geothermal Trade Association. Approximately 2,500 heat pump systems have been installed in Manitoba. In 2001, heat pump sales in Manitoba grew 40 per cent. 1 tab., 6 figs

Geothermal direct use engineering and design guidebook

International Nuclear Information System (INIS)

Lienau, P.J.; Lunis, B.C.

1991-01-01

The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States

Geothermal direct use engineering and design guidebook

Energy Technology Data Exchange (ETDEWEB)

Lienau, P.J.; Lunis, B.C. (eds.)

1991-01-01

The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States.

Geothermal direct use engineering and design guidebook

Energy Technology Data Exchange (ETDEWEB)

Bloomquist, R.G.; Culver, G.; Ellis, P.F.; Higbee, C.; Kindle, C.; Lienau, P.J.; Lunis, B.C.; Rafferty, K.; Stiger, S.; Wright, P.M.

1989-03-01

The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of these resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse, aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental considerations. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very potential in the United States.

DEVELOPING DIRECT USE OF GEOTHERMAL ENERGY IN ORADEA CITY

Directory of Open Access Journals (Sweden)

VASIU I.

2015-09-01

Full Text Available Thermal energy demand for district heating in the city of Oradea is supplied at present, almost at whole, by the Cogeneration Thermal Power Plant, based on classical fuels, mainly consisting of low grade coal and natural gas, with a small contribution of the geothermal energy. Geothermal resource at low enthalpy, located within the city area of Oradea, available at an estimated level of 250 GWh/year, exploited at present by 12 production wells, can provide a share of 55 GWh/year for district heating, representing at present about 7 % from the overall thermal demand at the end users inlet. Geothermal energy is delivered by means of 3 main thermal stations, in order to prepare, especially household warm water, but sometimes also secondary agent for space heating, using additionally heat, based on natural gas. At present, in the city area of Oradea, more than 7,000 dwellings are supplied by geothermal stations with warm water and in addition for about 3,400 dwellings is assured simultaneously warm water and space heating. Even if the geothermal energy provides at present only a small part of the overall heating requirement at the city level, nevertheless by increased financial support, in the near future is expected its much more contribution, as an alternative to polluting energy of coal and natural gas.

Geothermal direct-heat study: Imperial County, California

Energy Technology Data Exchange (ETDEWEB)

1983-05-01

Potential applications of geothermal energy which would be compatible with the agricultural activities in the county were identified and a plan to attract potential users to the area was developed. The intent of the first effort was to identify general classifications of industries which could utilize geothermal heat in production processes. Two levels of analyses were utilized for this effort. Initially, activities relying on previously developed engineering and industrial concepts were investigated to determine capital costs, employment, and potential energy savings. Second, innovative concepts not yet fully developed were investigated to determine their potential applicability to the agricultural base of the county. These investigations indicated that the major potential applications of geothermal heat would involve industries related to food processing or other direct agriculture-related uses of raw materials produced or imported to the county. An implementation plan which can be utilized by the county to market direct heat applications was developed. A socioeconomics analysis examined the potential effects on the county from development of direct heat projects. The county's planning and permitting requirements for dirct heat projects were also examined.

Experimental and CFD simulation of heat efficiency improvement in geothermal spas

International Nuclear Information System (INIS)

Jalilinasrabady, Saeid; Palsson, Halldor; Saevarsdottir, Gudrun; Itoi, Ryuichi; Valdimarsson, Pall

2013-01-01

Hot spas and jacuzzis are popular in Iceland due to the abundance of reasonably prized geothermal heat available. However the water from the DH (district heating) system is too warm to be admitted directly into the spa. For safety reasons the water is mixed with cold water, from 75 °C down to 50 °C, which leads to wasting a large quantity of heat. Therefore a design was suggested that enables the feeding of geothermal water directly into the pot, omitting the step of mixing it with cold water. The idea is to employ an open heat exchanger that transfers much heat from the geothermal water to the bulk water in the spa, before letting it mix with the spa water. A case study was done for one particular spa. Heat load was calculated and measured when the spa was in use, and when it was unused. A design is suggested employing a circular double-plate which is to be placed at bottom of pot. This unit will function as an open heat exchanger feeding DH water into the pot. Free convection takes place at the up side of the upper plate and forced convection below the upper plate. Heat-transfer coefficient for both was calculated. Temperature field in the pool before and after implementation of the open heat exchanger was measured at different points using thermocouples. The measured temperatures were compared to thermal and fluid-dynamic simulation of the temperature and flow fields obtaining good accordance. Results are reasonable and promising for a good design that may considerably reduce the energy expenses for a continuously heated geothermal spa. More detailed measurements were made on the upper plate of the heat exchanger and detailed simulation of the heat exchanger itself was then used to obtain a value for the heat-transfer coefficient for the upper plate to the surrounding water. This information was used to make an improved design for the open plate heat exchanger, stating that a diameter of 63 cm and a thickness of 1.5 cm were suggested as final design. Due to

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.

Using geothermal energy to heat a portion of a formation for an in situ heat treatment process

Science.gov (United States)

Pieterson, Roelof; Boyles, Joseph Michael; Diebold, Peter Ulrich

2010-06-08

Methods of using geothermal energy to treat subsurface formations are described herein. Methods for using geothermal energy to treat a subsurface treatment area containing or proximate to hydrocarbons may include producing geothermally heated fluid from at least one subsurface region. Heat from at least a portion of the geothermally heated fluid may be transferred to the subsurface treatment area to heat the subsurface treatment area. At least some hydrocarbon fluids may be produced from the formation.

Geothermal heat pumps - gaining ground in the UK and worldwide

International Nuclear Information System (INIS)

Curtis, Robin

2001-01-01

This 2001 edition of the guide to UK renewable energy companies examines the geothermal heat pump sector, and discusses the technology involved, installations of geothermal heat pumps, the activity in the UK market with increased interest in UK geothermal heat pump products from abroad, and developments in the building sector. The UK government's increased support for the industry including its sponsorship of the Affordable Warmth programme, and the future potential of ground source systems are discussed

Geothermal heating a handbook of engineering economics

CERN Document Server

Harrison, R; Smarason, O B

2013-01-01

To date all books on geothermics have emphasized its use for generating electricity, with applications of lower grade resources for direct heating meriting only a brief chapter. This book brings together research from a range of scientific journals and 'grey' literature to produce the first comprehensive text on geothermal heating. Economics form an important part of the book. It provides a step by step analysis of the various ways in which thermal waters can be used to provide space heating and of the advantages and disadvantages of different approaches. The final section of the book provides

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.

GEOTHERMAL / SOLAR HYBRID DESIGNS: USE OF GEOTHERMAL ENERGY FOR CSP FEEDWATER HEATING

Energy Technology Data Exchange (ETDEWEB)

Craig Turchi; Guangdong Zhu; Michael Wagner; Tom Williams; Dan Wendt

2014-10-01

This paper examines a hybrid geothermal / solar thermal plant design that uses geothermal energy to provide feedwater heating in a conventional steam-Rankine power cycle deployed by a concentrating solar power (CSP) plant. The geothermal energy represents slightly over 10% of the total thermal input to the hybrid plant. The geothermal energy allows power output from the hybrid plant to increase by about 8% relative to a stand-alone CSP plant with the same solar-thermal input. Geothermal energy is converted to electricity at an efficiency of 1.7 to 2.5 times greater than would occur in a stand-alone, binary-cycle geothermal plant using the same geothermal resource. While the design exhibits a clear advantage during hybrid plant operation, the annual advantage of the hybrid versus two stand-alone power plants depends on the total annual operating hours of the hybrid plant. The annual results in this draft paper are preliminary, and further results are expected prior to submission of a final paper.

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)

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

Status of geothermal energy in world and Turkey and studies in ITU

International Nuclear Information System (INIS)

Serpen, Umran

2006-01-01

After roughly 100 years of the first electricity generation, installed capacity of geothermal power plants have grown to 8900 MW in 25 countries, producing 56830 GWh/year. An estimate of the installed thermal power in the world for direct utilization at the end of 2004 is 27825 MW t . Thermal energy used is 261418 TJ/yr. The distribution of thermal energy used by category is approximately 33% for geothermal heat pumps, 29% for bathing and swimming, 20% for space heating (of which 77% for district heating), 7.5% for greenhouse heating and open ground heating, 4% for industrial process heat, 4% for aquaculture and 2% for others uses. A conventional steam cycle power plant with 17.8 MW e capacity was installed in Kizildere geothermal field and has been generating an average gross power of 10 MWe since 1984. An air cooled binary cycle power plant with gross capacity of 8.5 MW e is being built in Aydin-Salavatli has been in operation for two months. A decision was made to install another power plant with a capacity of 45 MW e in Aydin-Germencik that reservoir assessment studies are being conducted Direct utilization of geothermal resources in Turkey are about 500 MW t of which 250 MW t is used by district heating,140 MW t utilized by greenhouse heating and 100 MWt belong to bathing Turkeys geothermal potential as geothermal resource base was estimated as 3.1x10 2 3 J. Later information on the geothermal potential was provided by Serpen and Turkeys geothermal resource base was found 2.85x10 2 3 J. Recent studies by Serpen revealed Turkeys convertible energy from geothermal resources in 3 categories as 1.2E22 J for direct use (in two categories) and 1.3E18 J for indirect use. Stochastic studies conducted on economics of geothermal resources in Turkey by Serpen revealed that power generation looks profitable with the electricity selling prices of around 4.5-5 cents/kWh. The payout time for this type of investments reaches 7 to 8 years. District heating systems do not seem

Overview of direct use R&D at the Geo-Heat Center

Energy Technology Data Exchange (ETDEWEB)

Lienau, P.J.

1997-12-31

Geo-Heat Center research, during the past year, on geothermal district heating and greenhouse projects is intended to improve the design and cost effectiveness of these systems. The largest geothermal district heating system in the U.S., proposed at Reno, is describe and is one of 271 collocated sites in western states could benefit from the research. The geothermal district heating research investigated a variety of factors that could reduce development cost for residential areas. Many greenhouse operators prefer the {open_quotes}bare tube{close_quotes} type heating system. As facilities using these types of heating systems expand they could benefit from peaking with fossil fuels. It is possible to design a geothermal heating system for only 60% of the peak heat loss of a greenhouse and still meet over 90% of the annual heat energy needs of the structure. The design and cost effectiveness of this novel approach is summarized.

Phase 1 Feasibility Study, Canby Cascaded Geothermal Project, April 2, 2013

Energy Technology Data Exchange (ETDEWEB)

Merrick, Dale E [CanbyGeo, LLC

2013-04-02

A small community in Northern California is attempting to use a local geothermal resource to generate electrical power and cascade residual energy to an existing geothermal district heating system, greenhouse, and future fish farm and subsequent reinjection into the geothermal aquifer, creating a net-zero energy community, not including transportation.

Advanced concepts and solutions for geothermal heating applied in Oradea, Romania

Science.gov (United States)

Antal, C.; Popa, F.; Mos, M.; Tigan, D.; Popa, B.; Muresan, V.

2017-01-01

Approximately 70% of the total population of Oradea benefits from centralized heating, about 55,000 apartments and 159,000 inhabitants are connected. The heating system of Oradea consists of: sources of thermal energy production (Combined heat and power (CHP) I Oradea and geothermal water heating plants); a transport network of heat; heat distribution network for heating and domestic hot water; substations, most of them equipped with worn and obsolete equipment. Recently, only a few heat exchangers were rehabilitated and electric valves were installed to control the water flow. After heat extraction, geothermal chilled waters from the Oradea area are: discharged into the sewer system of the city, paying a fee to the local water company which manages the city’s sewers; discharged into the small river Peta; or re-injected into the reservoir. In order to ensure environmental protection and a sustainable energy development in Oradea, renewable sources of energy have been promoted in recent years. In this respect, the creation of a new well for geothermal water re-injection into the reservoir limits any accidental thermal pollution of the environment, while ensuring the conservation properties of the aquifer by recharging with geothermal chilled water. The paper presents the achievements of such a project whose aim is to replace thermal energy obtained from coal with geothermal heating. The novelty consists in the fact that within the substation we will replace old heat exchangers, circulation pumps and valves with fully automated substations operating in parallel on both a geothermal system and on a primary heating system of a thermal plant.

VII international district heating conference

International Nuclear Information System (INIS)

1988-01-01

The proceedings of the 7th International District Heating Conference contain the full texts of the 89 presented papers of which 11 fall under the INIS Subject Scope. The conference met in seven sessions and dealt with the following problem areas: design and optimization of systems of district heating, integration of the power system and the district heating systems, cooperation of nuclear and fossil burning sources in district heating systems, the use of specific nuclear power plants for heating purposes, questions of the control of systems of district heating, the development of components of heating networks, the reliability and design of heat supply pipes. (Z.M.)

ENERGY STAR Certified Geothermal Heat Pumps

Science.gov (United States)

Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Geothermal Heat Pumps that are effective as of January 1, 2012. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=geo_heat.pr_crit_geo_heat_pumps

Geothermal heat - The second stream for geothermal sectors; Electricity production: industries are facing the geological unexpected events; Heat networks: a new boom in France

International Nuclear Information System (INIS)

Minster, Jean-Francois; Appert, Olivier; Moisant, Francois; Salha, Bernard; Tardieu, Bernard; Florette, Marc; Basilico, Laurent

2013-01-01

A first article proposes an overview of recent development in the field of geothermal power (individual heat pumps, urban heating networks, electricity production in volcanic context, and possibility of non conventional fields). These developments are notably interesting in a context of an evolving energy mix. Some benefits of geothermal power are outlined: a reliable and predictable production, and a low footprint. An installation of deep geothermal power in Alsace is presented. By evoking the construction of three high-energy geothermal power stations by GDF Suez in Sumatra, a second article outlines the high costs associated with exploration drilling which can face geological difficulties. It indicates and comments the distribution of costs among exploration, confirmation, authorizations, drilling, steam collection, electric plant, and connection to the grid. The third and last article comments the development of heat networks in France, and more particularly in the Parisian Basin which has the highest concentration of low-energy geothermal exploitations

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.

Industrial excess heat for district heating in Denmark

International Nuclear Information System (INIS)

Bühler, Fabian; Petrović, Stefan; Karlsson, Kenneth; Elmegaard, Brian

2017-01-01

Highlights: •Method for utilisation potential of industrial excess heat for district heating. •Industrial excess heat from thermal processes is quantified at single production units. •Linking of industrial excess heat sources and district heating demands done in GIS. •Excess heat recovery using direct heat transfer and heat pumps. •5.1% of the Danish district heating demand could be supplied by industrial excess heat. -- Abstract: Excess heat is available from various sources and its utilisation could reduce the primary energy use. The accessibility of this heat is however dependent amongst others on the source and sink temperature, amount and potential users in its vicinity. In this work a new method is developed which analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal processes which equals 5.1% of the current demand. More than half of this heat was found to be usable directly, without the need for a heat pump.

Solar heat storages in district heating networks

Energy Technology Data Exchange (ETDEWEB)

Ellehauge, K. (Ellehauge og Kildemoes, AArhus (DK)); Engberg Pedersen, T. (COWI A/S, Kgs. Lyngby (DK))

2007-07-15

This report gives information on the work carried out and the results obtained in Denmark on storages for large solar heating plants in district heating networks. Especially in Denmark the share of district heating has increased to a large percentage. In 1981 around 33% of all dwellings in DK were connected to a district heating network, while the percentage in 2006 was about 60% (in total 1.5 mio. dwellings). In the report storage types for short term storage and long term storages are described. Short term storages are done as steel tanks and is well established technology widely used in district heating networks. Long term storages are experimental and used in connection with solar heating. A number of solar heating plants have been established with either short term or long term storages showing economy competitive with normal energy sources. Since, in the majority of the Danish district heating networks the heat is produced in co-generation plants, i.e. plants producing both electricity and heat for the network, special attention has been put on the use of solar energy in combination with co-generation. Part of this report describes that in the liberalized electricity market central solar heating plants can also be advantageous in combination with co-generation plants. (au)

The possibilities of geothermal heat in the Netherlands

International Nuclear Information System (INIS)

Walter, F.

1995-01-01

Attention is paid to the exploration and conversion methods of geothermal heat, investment and maintenance costs of geothermal power plants, both for the Dutch situation. Applications in different European countries are briefly discussed. 3 figs., 3 ills., 1 tab., 4 refs

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)

Implications of Spatial Variability in Heat Flow for Geothermal Resource Evaluation in Large Foreland Basins: The Case of the Western Canada Sedimentary Basin

Directory of Open Access Journals (Sweden)

Simon Weides

2014-04-01

Full Text Available Heat flow and geothermal gradient of the sedimentary succession of the Western Canada Sedimentary Basin (WCSB are mapped based on a large thermal database. Heat flow in the deep part of the basin varies from 30 mW/m2 in the south to high 100 mW/m2 in the north. As permeable strata are required for a successful geothermal application, the most important aquifers are discussed and evaluated. Regional temperature distribution within different aquifers is mapped for the first time, enabling a delineation of the most promising areas based on thermal field and aquifer properties. Results of previous regional studies on the geothermal potential of the WCSB are newly evaluated and discussed. In parts of the WCSB temperatures as high as 100–210 °C exist at depths of 3–5 km. Fluids from deep aquifers in these “hot” regions of the WCSB could be used in geothermal power plants to produce electricity. The geothermal resources of the shallower parts of the WCSB (>2 km could be used for warm water provision (>50 °C or district heating (>70 °C in urban areas.

IMPACT OF GEOTHERMAL GRADIENT ON GROUND SOURCE HEAT PUMP SYSTEM MODELING

Directory of Open Access Journals (Sweden)

Tomislav Kurevija

2014-07-01

Full Text Available 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 thermogeologic properties of ground. After abovementioned depth, increase of ground temperature is solely dependent on geothermal gradient. Accurately determined value of undisturbed ground temperature is beneficial for proper sizing of borehole heat exchangers. On practical example of building which is being heated and cooled with shallow geothermal resource, influences of undisturbed ground temperature and geothermal gradient, on size of borehole heat exchanger are going to be presented. Sizing of borehole heat exchanger was calculated with commercial software Ground Loop Designer (GLD, which uses modified line source and cylinder source solutions of heat conduction in solids.

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

Uses of geothermal energy in Jordan for heating greenhouses; project proposal

International Nuclear Information System (INIS)

Al-Dabbas, Moh'd A. F.; Masarwah, Rober; Elkarmi, Fawwaz

1993-08-01

A proposal for the exploration of geothermal energy in Jordan for heating greenhouses. The report gives some background information on geothermal anomalies in Jordan, and outlines some on-going uses of geothermal energy in various parts of Jordan. The proposal is modelled on the 2664 square meter Filclair Super 9 Multispan greenhouse from France. The overall cost of the project involves three variables, the cost of the borehole, the cost of the greenhouse, and the cost of engineering services. The total cost ranges between three to four million dollars depending on the quantity and quality of information to be collected from the borehole. The advantages of geothermal heating compared with oil heating are emphasized. The project will enable geothermal heating and horticultural production to be monitored throughout the year, will produce data enabling rational and reliable water resources management, and will produce environmentally clean and efficient energy. (A.M.H.). 1 tab. 1 map

Geothermal energy: clean power from the Earth's heat

Science.gov (United States)

Duffield, Wendell A.; Sass, John H.

2003-01-01

Societies in the 21st century require enormous amounts of energy to drive the machines of commerce and to sustain the lifestyles that many people have come to expect. Today, most of this energy is derived from oil, natural gas, and coal, supplemented by nuclear power. Local exceptions exist, but oil is by far the most common source of energy worldwide. Oil resources, however, are nonrenewable and concentrated in only a few places around the globe, creating uncertainty in long-term supply for many nations. At the time of the Middle East oil embargo of the 1970s, about a third of the United States oil supply was imported, mostly from that region. An interruption in the flow of this import disrupted nearly every citizen’s daily life, as well as the Nation’s economy. In response, the Federal Government launched substantial programs to accelerate development of means to increasingly harness “alternative energies”—primarily biomass, geothermal, solar, and wind. The new emphasis on simultaneously pursuing development of several sources of energy recognized the timeless wisdom found in the proverb of “not putting all eggs in one basket.” This book helps explain the role that geothermal resources can play in helping promote such diversity and in satisfying our Nation’s vast energy needs as we enter a new millennium. For centuries, people have enjoyed the benefits of geothermal energy available at hot springs, but it is only through technological advances made during the 20th century that we can tap this energy source in the subsurface and use it in a variety of ways, including the generation of electricity. Geothermal resources are simply exploitable concentrations of the Earth’s natural heat (thermal energy). The Earth is a bountiful source of thermal energy, continuously producing heat at depth, primarily by the decay of naturally occurring radioactive isotopes—principally of uranium, thorium, and potassium—that occur in small amounts in all rocks

Heat flow at the Platanares, Honduras, geothermal site

Science.gov (United States)

Meert, Joseph G.; Smith, Douglas L.

1991-03-01

Three boreholes, PLTG-1, PLTG-2 and PLTG-3, were drilled in the Platanares, Honduras geothermal system to evaluate the geothermal energy potential of the site. The maximum reservoir temperature was previously estimated at 225-240°C using various types of chemical and isotopic geothermometry. Geothermal gradients of 139-239°C/km, calculated from two segments of the temperature-depth profile for borehole PLTG-2, were used to project a minimum depth to the geothermal reservoir of 1.2-1.7 km. Borehole PLTG-1 exhibited an erratic temperature distribution attributed to fluid movement through a series of isolated horizontal and subhorizontal fractures. The maximum measured temperature in borehole PLTG-1 was 150.4°C, and in PLTG-2 the maximum measured temperature was 104.3°C. PLTG-3 was drilled after this study and the maximum recorded temperature of 165°C is similar to the temperature encountered in PLTG-1. Heat flow values of 392 mWm -2 and 266 mWm -2 represent the first directly-measured heat flow values for Honduras and northen Central America. Radioactive heat generation, based on gamma-ray analyses of uranium, thorium and potassium in five core samples, is less than 2.0 μWm -3 and does not appear to be a major source of the high heat flow. Several authors have proposed a variety of extensional tectonic environments for western Honduras and these heat flow values, along with published estimates of heat flow, are supportive of this type of tectonic regime.

Energy conversion processes for the use of geothermal heat

Energy Technology Data Exchange (ETDEWEB)

Minder, R. [Minder Energy Consulting, Oberlunkhofen (Switzerland); Koedel, J.; Schaedle, K.-H.; Ramsel, K. [Gruneko AG, Basel (Switzerland); Girardin, L.; Marechal, F. [Swiss Federal Institute of Technology (EPFL), Laboratory for industrial energy systems (LENI), Lausanne (Switzerland)

2007-03-15

This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of a study made on energy conversion processes that can be used when geothermal heat is to be used. The study deals with both theoretical and practical aspects of the conversion of geothermal heat to electricity. The report is divided into several parts and covers general study, practical experience, planning and operation of geothermal power plants as well as methodology for the optimal integration of energy conversion systems in geothermal power plants. In the first part, the specific properties and characteristics of geothermal resources are discussed. Also, a general survey of conversion processes is presented with special emphasis on thermo-electric conversion. The second part deals with practical aspects related to planning, construction and operation of geothermal power plant. Technical basics, such as relevant site-specific conditions, drilling techniques, thermal water or brine quality and materials requirements. Further, planning procedures are discussed. Also, operation and maintenance aspects are examined and some basic information on costs is presented. The third part of the report presents the methodology and results for the optimal valorisation of the thermodynamic potential of deep geothermal systems.

District heating in Italy

International Nuclear Information System (INIS)

Sacchi, E.

1998-01-01

The legislative act establishing the electric monopoly virtually shut out the district heating associated with electricity cogeneration, while other laws, issued to counteract the effects of oil shocks, allowed municipal utilities to do so. Thus, district heating has experienced some development, though well below its possibilities. The article analyses the reasons for this lagging, reports district heating data and projects its forecasts against the Kyoto Protocol objectives [it

Industrial excess heat for district heating in Denmark

DEFF Research Database (Denmark)

Bühler, Fabian; Petrovic, Stefan; Karlsson, Kenneth Bernard

2017-01-01

analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate...... the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity...... analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal...

Geothermal heat exchanger with coaxial flow of fluids

Directory of Open Access Journals (Sweden)

Pejić Dragan M.

2005-01-01

Full Text Available The paper deals with a heat exchanger with coaxial flow. Two coaxial pipes of the secondary part were placed directly into a geothermal boring in such a way that geothermal water flows around the outer pipe. Starting from the energy balance of the exchanger formed in this way and the assumption of a study-state operating regime, a mathematical model was formulated. On the basis of the model, the secondary circle output temperature was determined as a function of the exchanger geometry, the coefficient of heat passing through the heat exchange areas, the average mass isobaric specific heats of fluid and mass flows. The input temperature of the exchanger secondary circle and the temperature of the geothermal water at the exit of the boring were taken as known values. Also, an analysis of changes in certain factors influencing the secondary water temperature was carried out. The parameters (flow temperature of the deep boring B-4 in Sijarinska Spa, Serbia were used. The theoretical results obtained indicate the great potential of this boring and the possible application of such an exchanger.

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

Geothermal studies in oilfield districts of Eastern Margin of the Gulf of Suez, Egypt

OpenAIRE

Mohamed Abdel Zaher; Mohamed El Nuby; Essam Ghamry; Khamis Mansour; Nureddin M. Saadi; Heba Atef

2014-01-01

Results of geothermal studies carried out at 149 onshore oil wells have been used in evaluation of temperature gradient and heat flow values of the eastern shore of the Gulf of Suez. The investigations included temperature logs in boreholes, calculation of amplitude temperature, geothermal gradients and heat flow. The results obtained indicate that geothermal gradient values are in the ranges of 0.02–0.044 °C/m and regionally averaged mean heat flow values are found to fall in the interval of...

A lignite-geothermal hybrid power and hydrogen production plant for green cities and sustainable buildings

Energy Technology Data Exchange (ETDEWEB)

Kilkis, B. [Baskent University, Ankara (Turkey). Dept. of Mechanical Engineering

2011-02-15

Turkey is rich in both geothermal energy and lignite reserves, which in many cases, are co-located. This condition makes it feasible to utilize both lignite and geothermal energy in a hybrid form for combined power heat, and cold generation, which may lead to optimally energy and exergy efficient, environmentally benign, and economically sound applications. This paper presents a novel concept of hybrid lignite-geothermal plant for a district energy system and hydrogen production facility in Aydin with special emphasis on high performance, green buildings and green districts. In this concept, lignite is first introduced to a partially fluidized-bed gasifier and then to a fluidized-bed gas cleaning unit, which produces synthetic gas and finally hydrogen. The by-products, namely char and ash are used in a fluidized-bed combustor to produce power. Waste heat from all these steps are utilized in a district heating system along with heat received from geothermal production wells after power is generated there. H{sub 2}S gas obtained from the separator system is coupled with hydrogen production process at the lignite plant. Absorption cooling systems and thermal storage tanks complement the hybrid system for the tri-generation district energy system. On the demand side, the new, green OSTIM OSB administration building in Ankara is exemplified for greener, low-exergy buildings that will compound the environmental benefits.

Compact, Deep-Penetrating Geothermal Heat Flow Instrumentation for Lunar Landers

Science.gov (United States)

Nagihara, S.; Zacny, K.; Hedlund, M.; Taylor, P. T.

2012-01-01

Geothermal heat flow is obtained as a product of the two separate measurements of geothermal gradient in, and thermal conductivity of, the vertical soi/rock/regolith interval penetrated by the instrument. Heat flow measurements are a high priority for the geophysical network missions to the Moon recommended by the latest Decadal Survey [I] and previously the International Lunar Network [2]. The two lunar-landing missions planned later this decade by JAXA [3] and ESA [4] also consider geothermal measurements a priority.

Geothermal heating saves energy

International Nuclear Information System (INIS)

Romsaas, Tor

2003-01-01

The article reviews briefly a pioneer project for a construction area of 200000 m''2 with residences, business complexes, a hotel and conference centre and a commercial college in Oslo. The energy conservation potential is estimated to be about 60-70 % compared to direct heating with oil, gas or electricity as sources. There will also be substantial reduction in environmentally damaging emissions. The proposed energy central combines geothermal energy sources with heat pump technology, utilises water as energy carrier and uses terrestrial wells for energy storage. A cost approximation is presented

Environmental Assessment Lakeview Geothermal Project

Energy Technology Data Exchange (ETDEWEB)

Treis, Tania [Southern Oregon Economic Development Department, Medford, OR (United States)

2012-04-30

The Town of Lakeview is proposing to construct and operate a geothermal direct use district heating system in Lakeview, Oregon. The proposed project would be in Lake County, Oregon, within the Lakeview Known Geothermal Resources Area (KGRA). The proposed project includes the following elements: Drilling, testing, and completion of a new production well and geothermal water injection well; construction and operation of a geothermal production fluid pipeline from the well pad to various Town buildings (i.e., local schools, hospital, and Lake County Industrial Park) and back to a geothermal water injection well. This EA describes the proposed project, the alternatives considered, and presents the environmental analysis pursuant to the National Environmental Policy Act. The project would not result in adverse effects to the environment with the implementation of environmental protection measures.

Research report on promotion of geothermal energy exploitation for fiscal 1997. Test drilling into the structure, construction work for research, and analysis (No.B-4 Kuenohira district); 1997 nendo chinetsu kaihatsu sokushin chosa. Kozo shisui chosa koji oyobi kaiseki hokokusho (No.B-4 Kuenohirayama chiiki)

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-06-01

Cuttings from a test drilling in the Kuenohira district, Oita Prefecture, are subjected to analysis. The result of ground surface investigation suggested the presence of a magma reservoir to serve as heat source and a highly permeable zone along a fault to help the formation of a thermal water retention system. At the N9-KH-1 drilling site, however, no geothermal reservoir is found along the periphery of the subsidence in the western part of the research area. In this district, it is deemed, no geothermal reservoir has been formed due to shortage of heat supply from the heat source and insufficient geothermal water activity. It is also deemed that the district, in which fractures of the E-W system, NNW-SSE system, and NE-SW system are distributed, is a region at which meteoric water flows into larger convection systems. As for the westward stretch of the geothermal reservoir (where the N9-KH-1 site is situated) that has developed on the swell of the basement, detected to exist at N2-MW-2 and N3-MW-6 in the eastern part of the research area, it is found to be not so extensive. (NEDO)

Borehole heat exchangers: Longterm operational characteristics of a decentral geothermal heating system

International Nuclear Information System (INIS)

Rybach, L.; Eugster, W.J.; Hopkirk, R.J.; Kaelin, B.

1992-01-01

The heat pump-coupled borehole heat exchanger (BHE) is an efficient and small geothermal energy system for supplying heat typically to a single dwelling house. The long-term performance characteristics have been investigated by computer simulations. The numerical models were validated by measurements at instrumented BHE facilities. The results show the development of a new thermal equilibrium state after the first few years of BHE operation. The thermal influence is limited to the first few meters of the ground surrounding the BHE. The BHE could be scaled up in order to be installed in deep 'failed' holes (e.g. dry geothermal or hydrocarbon exploration holes)

Geothermal Direct-Heat Utilization Assistance - Final Report

Energy Technology Data Exchange (ETDEWEB)

J. W. Lund

1999-07-14

The Geo-Heat Center provided (1) direct-use technical assistance, (2) research, and (3) information dissemination on geothermal energy over an 8 1/2 year period. The center published a quarterly bulletin, developed a web site and maintained a technical library. Staff members made 145 oral presentations, published 170 technical papers, completed 28 applied research projects, and gave 108 tours of local geothermal installations to 500 persons.

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.

ENERGY STAR Certified Geothermal Heat Pumps

Data.gov (United States)

U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.1 ENERGY STAR Program Requirements for Geothermal Heat Pumps that are effective as of...

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

Geothermal Energy Utilization in the United States - 2000

Energy Technology Data Exchange (ETDEWEB)

Lund, John W.; Boyd, Tonya L (Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR); Sifford, Alex (Sifford Energy Services, Neskowin, OR); Bloomquist, R. Gordon (Washington State University Energy Program, Olympia, WA)

2000-01-01

Geothermal energy is used for electric power generation and direct utilization in the United States. The present installed capacity for electric power generation is 3,064 MWe with only 2,212 MWe in operation due to reduction at The Geysers geothermal field in California; producing approximately16,000 GWh per year. Geothermal electric power plants are located in California, Nevada, Utah and Hawaii. The two largest concentrations of plants are at The Geysers in northern California and the Imperial Valley in southern California. The direct utilization of geothermal energy includes the heating of pools and spas, greenhouses and aquaculture facilities, space heating and district heating, snow melting, agricultural drying, industrial applications and ground-source heat pumps. The installed capacity is 4,000 MWt and the annual energy use is 20,600 billion Btu (21,700 TJ - 6040 GWh). The largest applications is groundsource (geothermal) heat pumps (59% of the energy use), and the largest direct-use is in aquaculture. Direct utilization is increasing at about six percent per year; whereas, electric power plant development is almost static. Geothermal energy is a relatively benign energy source, displaying fossil fuels and thus, reducing greenhouse gas emissions. A recent initiative by the U.S. Department of Energy, “Geo-Powering the West,” should stimulate future geothermal development. The proposal is especially oriented to small-scale power plants with cascaded uses of the geothermal fluid for direct applications.

Geothermal energy utilization in the United States - 2000

Energy Technology Data Exchange (ETDEWEB)

Lund, John W.; Boyd, Tonya L.; Sifford, Alex; Bloomquist, R. Gordon

2000-01-01

Geothermal energy is used for electric power generation and direct utilization in the United States. The present installed capacity for electric power generation is 3,064 MWe with only 2,212 MWe in operation due to reduction at The Geysers geothermal field in California; producing approximately16,000 GWh per year. Geothermal electric power plants are located in California, Nevada, Utah and Hawaii. The two largest concentrations of plants are at The Geysers in northern California and the Imperial Valley in southern California. The direct utilization of geothermal energy includes the heating of pools and spas, greenhouses and aquaculture facilities, space heating and district heating, snow melting, agricultural drying, industrial applications and ground-source heat pumps. The installed capacity is 4,000 MWt and the annual energy use is 20,600 billion Btu (21,700 TJ - 6040 GWh). The largest applications is groundsource (geothermal) heat pumps (59% of the energy use), and the largest direct-use is in aquaculture. Direct utilization is increasing at about six percent per year; whereas, electric power plant development is almost static. Geothermal energy is a relatively benign energy source, displaying fossil fuels and thus, reducing greenhouse gas emissions. A recent initiative by the U.S. Department of Energy, “Geo-Powering the West,” should stimulate future geothermal development. The proposal is especially oriented to small-scale power plants with cascaded uses of the geothermal fluid for direct applications.

FY 1974 Report on results of Sunshine Project. Study on physicochemical properties of rocks in geothermal districts; 1974 nendo chinetsu chitai ni okeru ganseki no butsuri kagakuteki tokusei ni kansuru kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-03-01

The geothermal district is characterized by distributions of high temperature and hot water. The beds and rocks in these areas are characteristically altered by these conditions. It is an object of this research and development project to clarify how properties of the beds and rocks in these areas, exposed to the characteristic physicochemical conditions, differ from properties of those in other areas. There are may rock properties. In this project, the studied properties are centered by those used for physical exploitation (or geophysical methods), e.g., electrical properties (electrical exploitation), magnetic properties (magnetic exploitation), and thermal conductivity (measurement of heat flow rates and geothermal gradients). The FY 1974 project covers pigeonholing the basic data, establishment of the experimental procedures, and measurement of water quality characteristics and temperature distributions (geothermal temperature gradients) at the test site. This paper reports the results categorized by (I) measurement of rock resistivity and effects on moisture content on this property, (II) properties of water in the geothermal district (Yahata-daira District), and (III) relationships between rock thermal conductivity and other properties. (NEDO)

Geothermal Heat Pump Benchmarking Report

Energy Technology Data Exchange (ETDEWEB)

None

1997-01-17

A benchmarking study was conducted on behalf of the Department of Energy to determine the critical factors in successful utility geothermal heat pump programs. A Successful program is one that has achieved significant market penetration. Successfully marketing geothermal heat pumps has presented some major challenges to the utility industry. However, select utilities have developed programs that generate significant GHP sales. This benchmarking study concludes that there are three factors critical to the success of utility GHP marking programs: (1) Top management marketing commitment; (2) An understanding of the fundamentals of marketing and business development; and (3) An aggressive competitive posture. To generate significant GHP sales, competitive market forces must by used. However, because utilities have functioned only in a regulated arena, these companies and their leaders are unschooled in competitive business practices. Therefore, a lack of experience coupled with an intrinsically non-competitive culture yields an industry environment that impedes the generation of significant GHP sales in many, but not all, utilities.

Geothermal heat pumps as one of possibilities of an alternative energy used for objects heating objects in Czech Republic

Directory of Open Access Journals (Sweden)

Jiří Ryška

2007-06-01

Full Text Available The use of geothermal energy for more localised energy requirements is becoming more apparent with the use of geothermal heat pumps. The use of heat from the upper portion of the earth's crust can be useful and efficient method of energy saving. At around 50 m below the earth's surface the ambient temperature fluctuates between around 8-12 oC. This heat can be used by being transferred to the surface via a loop system using a high-efficiency refrigerant type of material.These systems are also typically more efficient than gas or oil-fired heating systems. They are more energy efficient than air-source heat pumps because they draw heat from, or release heat to, the earth, which has moderate temperatures all the year, rather than to the air. Geothermal heat pumps use the relatively constant temperature of the ground or water several meters below the earth's surface as source of heating and cooling. Geothermal heat pumps are appropriate for retrofit or new homes, where both heating and cooling are desired. In addition to heating and cooling, geothermal heat pumps can provide domestic hot water. They can be used for virtually any home size or lot in any region of the Czech Republic.

Procedures for selecting and buying district heating equipment. Sofia district heating. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-11-01

The aim of this Final Report, prepared for the project `Procedures for Selecting and Buying DistRict Heating Equipment - Sofia District Heating Company`, is to establish an overview of the activities accomplished, the outputs delivered and the general experience gained as a result of the project. The main objective of the project is to enable Sofia District Heating Company to prepare specifications and tender documents, identify possible suppliers, evaluate offers, etc. in connection with purchase of district heating equipment. This objective has been reached by using rehabilitation of sub-stations as an example requested by Sofia DH. The project was originally planned to be finalized end of 1995, but due to the extensions of the scope of work, the project has been prolonged until end 1997. The following main activities were accomplished: Preparation of a detailed work plan; Collection of background information; Discussion and advice about technical specifications and tender documents for sub-station rehabilitation; Input to terms of reference for a master plan study; Input to technical specification for heat meters; Collection of ideas for topics and examples related to dissemination of information to consumers about matters related to district heating consumption. (EG)

Turkish tomato greenhouse gets geothermal heating

NARCIS (Netherlands)

Sikkema, A.; Maaswinkel, R.H.M.

2011-01-01

Wageningen UR Greenhouse Horticulture will set up an ultramodern greenhouse in Turkey, together with Dutch greenhouse builders and contractors. Geothermal energy will be used there to provide heat and carbon dioxide for tomato cultivation.

Numerical Simulation of Nanofluid Suspensions in a Geothermal Heat Exchanger

OpenAIRE

Xiao-Hui Sun; Hongbin Yan; Mehrdad Massoudi; Zhi-Hua Chen; Wei-Tao Wu

2018-01-01

It has been shown that using nanofluids as heat carrier fluids enhances the conductive and convective heat transfer of geothermal heat exchangers. In this paper, we study the stability of nanofluids in a geothermal exchanger by numerically simulating nanoparticle sedimentation during a shut-down process. The nanofluid suspension is modeled as a non-linear complex fluid; the nanoparticle migration is modeled by a particle flux model, which includes the effects of Brownian motion, gravity, turb...

Geothermal direct use developments in the United States

Energy Technology Data Exchange (ETDEWEB)

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

1988-08-01

Direct heat use of geothermal energy in the United States is recognized as one of the alternative energy resources that has proven itself technically and economically, and is commercially available. Developments include space conditioning of buildings, district heating, groundwater heat pumps, greenhouse heating, industrial processing, aquaculture, and swimming pool heating. Forty-four states have experienced significant geothermal direct use development in the last ten years. The total installed capacity is 5.7 billion Btu/hr (1700 MW/sub t/), with an annual energy use of nearly 17,000 billion Btu/yr (4.5 million barrels of oil energy equivalent). In this report we provide an overview of how and where geothermal energy is used, the extent of that use, the economics and growth trends. The data is based on an extensive site data gathering effort by the Geo-Heat Center in the spring of 1988, under contract to the US Department of Energy. 100 refs., 4 figs., 4 tabs.

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

Geothermal heat pump performance

Energy Technology Data Exchange (ETDEWEB)

Boyd, Tonya L.; Lienau, Paul J.

1995-01-01

Geothermal heat pump systems are a promising new energy technology that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to customers and utilities in energy (kWh) and demand (kW) savings. The purpose of this study was to determine what existing monitored data was available mainly from electric utilities on heat pump performance, energy savings and demand reduction for residential, school, and commercial building applications. Information was developed on the status of electric utility marketing programs, barriers to market penetration, incentive programs, and benefits.

Geothermal Heat Pump Performance

Energy Technology Data Exchange (ETDEWEB)

Boyd, Tonya L.; Lienau, Paul J.

1995-01-01

Geothermal heat pump systems are a promising new energy technology that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to customers and utilities in energy (kWh) and demand (kW) savings. The purpose of this study was to determine what existing monitored data was available mainly from electric utilities on heat pump performance, energy savings and demand reduction for residential, school, and commercial building applications. Information was developed on the status of electric utility marketing programs, barriers to market penetration, incentive programs, and benefits.

District heating in sequential energy supply

International Nuclear Information System (INIS)

Persson, Urban; Werner, Sven

2012-01-01

Highlights: ► European excess heat recovery and utilisation by district heat distribution. ► Heat recovery in district heating systems – a structural energy efficiency measure. ► Introduction of new theoretical concepts to express excess heat recovery. ► Fourfold potential for excess heat utilisation in EU27 compared to current levels. ► Large scale excess heat recovery – a collaborative challenge for future Europe. -- Abstract: Increased recovery of excess heat from thermal power generation and industrial processes has great potential to reduce primary energy demands in EU27. In this study, current excess heat utilisation levels by means of district heat distribution are assessed and expressed by concepts such as recovery efficiency, heat recovery rate, and heat utilisation rate. For two chosen excess heat activities, current average EU27 heat recovery levels are compared to currently best Member State practices, whereby future potentials of European excess heat recovery and utilisation are estimated. The principle of sequential energy supply is elaborated to capture the conceptual idea of excess heat recovery in district heating systems as a structural and organisational energy efficiency measure. The general conditions discussed concerning expansion of heat recovery into district heating systems include infrastructure investments in district heating networks, collaboration agreements, maintained value chains, policy support, world market energy prices, allocation of synergy benefits, and local initiatives. The main conclusion from this study is that a future fourfold increase of current EU27 excess heat utilisation by means of district heat distribution to residential and service sectors is conceived as plausible if applying best Member State practice. This estimation is higher than the threefold increase with respect to direct feasible distribution costs estimated by the same authors in a previous study. Hence, no direct barriers appear with

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.

Geothermal source heat pump performance for a greenhouse heating system: an experimental study

Directory of Open Access Journals (Sweden)

Alexandros Sotirios Anifantis

2016-09-01

Full Text Available Greenhouses play a significant function in the modern agriculture economy even if require great amount of energy for heating systems. An interesting solution to alleviate the energy costs and environmental problems may be represented by the use of geothermal energy. The aim of this paper, based on measured experimental data, such as the inside greenhouse temperature and the heat pump performance (input and output temperatures of the working fluid, electric consumption, was the evaluation of the suitability of low enthalpy geothermal heat sources for agricultural needs such as greenhouses heating. The study was carried out at the experimental farm of the University of Bari, where a greenhouse was arranged with a heating system connected to a ground-source heat pump (GSHP, which had to cover the thermal energy request. The experimental results of this survey highlight the capability of the geothermal heat source to ensue thermal conditions suitable for cultivation in greenhouses even if the compressor inside the heat pump have operated continuously in a fluctuating state without ever reaching the steady condition. Probably, to increase the performance of the heat pump and then its coefficient of performance within GSHP systems for heating greenhouses, it is important to analyse and maximise the power conductivity of the greenhouse heating system, before to design an expensive borehole ground exchanger. Nevertheless, according to the experimental data obtained, the GSHP systems are effective, efficient and environmental friendly and may be useful to supply the heating energy demand of greenhouses.

Recent trends in the development of heat exchangers for geothermal systems

Science.gov (United States)

Franco, A.; Vaccaro, M.

2017-11-01

The potential use of geothermal resources has been a remarkable driver for market players and companies operating in the field of geothermal energy conversion. For this reason, medium to low temperature geothermal resources have been the object of recent rise in consideration, with strong reference to the perspectives of development of Organic Rankine Cycle (ORC) technology. The main components of geothermal plants based on ORC cycle are surely the heat exchangers. A lot of different heat exchangers are required for the operation of ORC plants. Among those it is surely of major importance the Recovery Heat Exchanger (RHE, typically an evaporator), in which the operating fluid is evaporated. Also the Recuperator, in regenerative Organic Rankine Cycle, is of major interest in technology. Another important application of the heat exchangers is connected to the condensation, according to the possibility of liquid or air cooling media availability. The paper analyzes the importance of heat exchangers sizing and the connection with the operation of ORC power plants putting in evidence the real element of innovation: the consideration of the heat exchangers as central element for the optimum design of ORC systems.

Seon heats with geothermal energy

International Nuclear Information System (INIS)

Hawkins, A.C.

2001-01-01

This article describes the combined use of ground water for the supply of drinking water for the municipality of Seon, Switzerland and as the basis for a district heating system. The use of the water, pumped up from a depth of 300 meters and exhibiting a temperature of 19.5 o C, as the heat source for heat pumps is described. The history of the project is discussed and figures are given on the district heating system that provides heat for an indoor swimming pool complex, industry and living accommodation in the village. Operational strategies used to make optimum use of tariff structures are described. The role played by local initiative in this innovative project is emphasised

Geothermal Heat Flux Underneath Ice Sheets Estimated From Magnetic Satellite Data

DEFF Research Database (Denmark)

Fox Maule, Cathrine; Purucker, M.E.; Olsen, Nils

The geothermal heat flux is an important factor in the dynamics of ice sheets, and it is one of the important parameters in the thermal budgets of subglacial lakes. We have used satellite magnetic data to estimate the geothermal heat flux underneath the ice sheets in Antarctica and Greenland...

Heat Pumps in Subarctic Areas

DEFF Research Database (Denmark)

Atlason, Reynir Smari; Oddsson, Gudmundur Valur; Unnthorsson, Runar

2017-01-01

Geothermal heat pumps use the temperature difference between inside and outside areas to modify a refrigerant, either for heating or cooling. Doing so can lower the need for external heating energy for a household to some extent. The eventual impact depends on various factors, such as the external...... source for heating or cooling and the temperature difference. The use of geothermal heat pumps, and eventual benefits has not been studied in the context of frigid areas, such as in Iceland. In Iceland, only remote areas do not have access to district heating from geothermal energy where households may...... therefor benefit from using geothermal heat pumps. It is the intent of this study to explore the observed benefits of using geothermal heat pumps in Iceland, both financially and energetically. This study further elaborates on incentives provided by the Icelandic government. Real data was gathered from...

Geothermal resources of the UK

International Nuclear Information System (INIS)

Batchelor, A.S.

1990-01-01

This paper reports that geothermal energy applications and research are being actively pursued in the United Kingdom despite the relatively normal heat flow regime. The cumulative expenditure on geothermal activity from 1975 to 1989 has been approximately Brit-pounds 46 million of 32% of the Renewable Energy Research Budget to date. The first practical application is a 2 MWt scheme at Southampton as part of a district heating scheme. Commercial operation started in February 1988 and further expansion is planned. The UK's enthusiasm for Hot Dry Rock has dimmed slightly as the entire program is reappraised and the long heralded deep exploration hole has yet to materialize. Future activity looks likely to focus on geothermal opportunities that have multiple uses or applications for the fluids in small scale schemes and Hot Dry Rock research will probably be linked to a pan-European program based in France

Study of the Dependence Effectiveness of Low-potential Heat of the Ground and Atmospheric Air for Heating Buildings from Climatic parameters

Directory of Open Access Journals (Sweden)

Vasilyev Gregory P.

2016-01-01

Full Text Available The article represents the results of researches for division into districts of the territory of Russia and Europe by efficiency of using for the heat supply of buildings of low-potential thermal energy of ground and free air and their combination. While modeling of the heat regime of geothermal HPS in climatic conditions of different regions of the territory of Russia, the influence has been taken into account of the long-term extraction of geothermal heat energy on the ground heat regime as well as the influence of phase transitions of pore moisture in ground on the efficiency of operation of geothermal heat-pump heat-supply systems. While realization of the division into districts, the sinking of temperatures of ground massive was been taken into account which has been called by long-term extraction of the heat energy from the ground, and as calculation parameters of the heat energy from the ground, and as calculation parameters of ground massive temperatures, the ground temperatures were used which are waited for the 5-th year of operation of geothermal HPS.

Geothermal direct-heat utilization assistance. Quarterly project progress report, July 1996--September 1996. Federal Assistance Program

Energy Technology Data Exchange (ETDEWEB)

Lienau, P.

1996-11-01

This report summarizes geothermal technical assistance, R&D and technology transfer activities of the Geo-Heat Center at Oregon Institute of Technology for the fourth quarter of FY-96. It describes 152 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, economics and resources. Research activities are summarized on greenhouse peaking. Outreach activities include the publication of a geothermal direct use Bulletin, dissemination of information, geothermal library, technical papers and seminars, and progress monitor reports on geothermal resources and utilization.

Evaluation of the Theoretical Geothermal Potential of Inferred Geothermal Reservoirs within the Vicano–Cimino and the Sabatini Volcanic Districts (Central Italy by the Application of the Volume Method

Directory of Open Access Journals (Sweden)

Daniele Cinti

2018-01-01

Full Text Available The evaluation of the theoretical geothermal potential of identified unexploited hydrothermal reservoirs within the Vicano–Cimino and Sabatini volcanic districts (Latium region, Italy has been made on the basis of a revised version of the classical volume method. This method is based on the distribution of the partial pressure of CO2 (pCO2 in shallow and deep aquifers to delimit areas of geothermal interest, according to the hypothesis that zones of high CO2 flux, either from soil degassing and dissolved into aquifers, are spatially related to deep hydrothermal reservoirs. On the whole, 664 fluid discharges (cold waters, thermal waters, and bubbling pools have been collected from shallow and deep aquifers in the Vicano–Cimino Volcanic District and the Sabatini Volcanic District for chemical and isotopic composition, in an area of approximately 2800 km2. From this large hydro-geochemical dataset the pCO2 values have been computed and then processed to obtain a contour map of its spatial distribution by using geostatistical techniques (kriging. The map of pCO2 has been used to draw up the boundaries of potentially exploitable geothermal systems within the two volcanic districts, corresponding to the areas where endogenous CO2 raise up to the surface from the deep hydrothermal reservoirs. The overall estimated potential productivities and theoretical minimum and maximum thermal power of the two volcanic districts are of about 45 × 103 t/h and 3681–5594 MWt, respectively. This makes the Vicano–Cimino Volcanic District and the Sabatini Volcanic District very suitable for both direct and indirect exploitation of the geothermal resources, in view of the target to reduce electricity generation from conventional and poorly sustainable energy sources.

Heat Flow and Geothermal Potential in the South-Central United States

International Nuclear Information System (INIS)

Negraru, Petru T.; Blackwell, David D.; Erkan, Kamil

2008-01-01

Geothermal exploration is typically limited to high-grade hydrothermal reservoirs that are usually found in the western United States, yet large areas with subsurface temperatures above 150 deg. C at economic drilling depths can be found east of the Rocky Mountains. The object of this paper is to present new heat flow data and to evaluate the geothermal potential of Texas and adjacent areas. The new data show that, west of the Ouachita Thrust Belt, the heat flow values are lower than east of the fault zone. Basement heat flow values for the Palo Duro and Fort Worth Basins are below 50 mW/m 2 while, in the frontal zone of the belt, they can exceed 60 mW/m 2 . Further east, along the Balcones fault system the heat flow is in general higher than 55 mW/m 2 . The eastern most heat flow sites are in Louisiana and they show very high heat flow (over 80 mW/m 2 ), which is associated with the apparently highly radioactive basement of the Sabine uplift. The geothermal resource in this area is large and diverse, and can be divided in high grade (temperature above 150 deg. C) convective systems, conductive based enhanced geothermal systems and geothermal/geopressured systems. One of the most attractive areas east of the cordillera extends from eastern Texas across Louisiana and Arkansas to western Mississippi. Here temperatures reach exploitation range at depths below 4 km, and tapping such a resource from shut in hydrocarbon fields is relatively easy. The initial costs of the development can be greatly reduced if existing hydrocarbon infrastructure is used, and therefore using shut-in hydrocarbon fields for geothermal purposes should not be neglected

Necessary for usage of geothermal heat pump, v. 14(53)

International Nuclear Information System (INIS)

Dimitrov, Konstantin; Armenski, Slave; Gacevski, Marjan

2006-01-01

Every day we are witnesses of constantly rapid increase of consumption of electric energy in R. of Macedonia as so as in the other countries in all the world. This rapid increase of consumption of electric energy independent of a lot of electrical units, which are applying in human life like: homes, administration and publication objects, as so as idently in industry. All of this conditions make us to thinking how is possible more rational consumption of electric energy in all areas in human life. One of the possible manners to reduce the consumption of electrical energy for heating and cooling is to use geothermal pumps. In this paper will be proposed geothermal heat pump, which is going to use the heat of earth by vertical and horizontal cupper pipe heat exchanger with data from GHP (Geothermal Heat Pump) NORDIC, factory in Canada. Also, it will be examined all parameters and done comparison with already existing ones. It is analyzed comparation of GHP with other energy units and what it means for rationally consumption of electric energy, economic saving and ecology saving. (Author)

Geothermal Direct-Heat Utilization Assistance - Final Report; FINAL

International Nuclear Information System (INIS)

J. W. Lund

1999-01-01

The Geo-Heat Center provided (1) direct-use technical assistance, (2) research, and (3) information dissemination on geothermal energy over an 8 1/2 year period. The center published a quarterly bulletin, developed a web site and maintained a technical library. Staff members made 145 oral presentations, published 170 technical papers, completed 28 applied research projects, and gave 108 tours of local geothermal installations to 500 persons

Ground source geothermal heat. Ground source heat pumps and underground thermal energy storage systems. Proceedings; Oberflaechennahe Geothermie. Erdgekoppelte Waermepumpen und unterirdische thermische Energiespeicher. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

At the ninth international user forum on shallow geothermal heat on 28th and 29th April, 2009, at BadStaffelstein (Federal Republic of Germany), the following lectures were held: (1) Information system on shallow geothermal heat for Bavaria (Marcellus Schulze); (2) Calculation of the spreading of temperature anomalies in groundwater as an instrument of planning of heat pump systems (Wolfgang Rauch); (3) Comparison of models for simulation of deep geothermal probes (Markus Proell); (4) Impact of the geometry of boreholes and probes on heat transport (Manfred Reuss); (5) Thermal respond tests and temperature depth profiles - Experience from research and practice (Markus Kuebert); (6) A model of simulation for the investigation of the impact of different heat transfer fluids on the efficiency of ground source heat pump devices (Roland Koenigsdorff); (7) The research project EWSplus - Investigations for quality assurance of geothermal probes (Mathieu Riegger); (8) Quality management of plants for the utilization of shallow geothermal heat with geothermal probes - the example of Baden-Wuerttemberg (Bruno Lorinser, Ingrid Stober); (9) Not every heat pump contributes to climate protection (Falk Auer); (10) Field measurements of heat pumps in residential buildings with modern standard and in older buildings (Marek Miara); (11) System technology for a great annual performance factor (Werner Schenk); (12) Modification of older geothermal heat probe devices for use with modern heat pumps (Klaus Friedrich Staerk); (13) Energy-efficient modernisation of a pensioners' condominium from the 1970s with solar-geothermal-air (Michael Guigas); (14) Evaluation and optimization of operation of seasonal storage systems in the foundations of office buildings (Herdis Kipry); (15) Evaluation of an innovative heating and cooling concept with rain water vessels, thermo-active building components and phase change materials in a residential building (Doreen Kalz); (16) Contracts for ground

Geothermal heat pumps, a booming technology in North America; Geothermal Heat Pumps - der Boom der oberflaechennahen Geothermie in Nordamerika

Energy Technology Data Exchange (ETDEWEB)

Sanner, B [Giessen Univ. (Germany). Inst. fuer Angewandte Geowissenschaften

1997-12-01

Over the last years, the interest in and the use of ground-source heat pumps has substantially increased in North America. In a market dominated by space cooling heat pumps can show clearly their advantages. This paper describes the development in Canada and USA, gives examples of the technologies used and presents some large plants. The differences to the Central European situation are discussed. Also mentioned are the various activities in market penetration, which peaked in the foundation of the `Geothermal Heat Pump Consortium` in Washington in 1994. (orig.) [Deutsch] In den letzten Jahren hat das Interesse an und der Einsatz von erdgekoppelten Waermepumpen in Nordamerika stark zugenommen. In einem von der Raumkuehlung dominierten Markt koennen Waermepumpen ihre Vorteile voll ausspielen. Der Beitrag beschreibt die Entwicklung in Kanada und den USA, stellt Beispiele der eingesetzten Technik vor und geht auf einige Grossanlagen ein. Ausserdem werden die Unterschiede zu der Situation in Mitteleuropa herausgearbeitet und die verschiedenen Aktivitaeten zu `Markt Penetration` behandelt, die 1994 in die Gruendung des `Geothermal Heat Pump Consortiums` in Washington muendeten. (orig.)

Economic viability of geothermal energy usage in comparison to renewable and conventional energy systems

International Nuclear Information System (INIS)

Schaumann, G.

2002-01-01

This comprehensive lecture given by Prof. Dr. Gunter Schaumann in Bad Duerkheim, Germany, discusses the use of geothermal energy in relationship to other forms of renewable energy sources and conventional energy technologies used to provide heat, power and motive force. The characteristics of geothermal energy from various sources and examples of its possible use are discussed. In particular, the paper deals with deep geothermal energy, which can provide heating energy for district heating schemes, if necessary with the help of heat pumps. The prospects of such a use of geothermal energy in the next 50 years in various suitable regions in Germany is discussed and the associated prerequisites are listed. The present situation concerning the use of geothermal energy in Germany is examined. An example of a geothermal heating power station that also features a gas-fired combined heat and power installation, a heat pump and a peak-load boiler is given. Also, the generation of electrical power using the Organic Rankine Cycle is discussed. The factors influencing the economic viability of geothermal power stations are discussed in detail and the resulting energy prices are compared with conventional plants. The paper gives details of the calculation of investment and energy costs for heat and power generation and presents figures based on exemplary installations

Some Problems of the Integration of Heat Pump Technology into a System of Combined Heat and Electricity Production

Directory of Open Access Journals (Sweden)

G. Böszörményi

2001-01-01

Full Text Available The closure of a part of the municipal combined heat and power (CHP plant of Košice city would result in the loss of 200 MW thermal output within a realtively short period of time. The long term development plan for the Košice district heating system concentrates on solving this problem. Taking into account the extremely high (90 % dependence of Slovakia on imported energy sources and the desirability of reducing the emission of pollutantst the alternative of supplying of 100 MW thermal output from geothermal sources is attractive. However the indices of economic efficiency for this alternative are unsatisfactory. Cogeneration of electricity and heat in a CHP plant, the most efficient way of supplying heat to Košice at the present time. If as planned, geothermal heat is fed directly into the district heating network the efficiency would be greatly reduced. An excellent solution of this problem would be a new conception, preferring the utilization of geothermal heat in support of a combined electricity and heat production process. The efficiency of geothermal energy utilization could be increased through a special heat pump. This paper deals with several aspects of the design of a heat pump to be integrated into the system of the CHP plant.

Heat pumps for geothermal applications: availability and performance. Final report

Energy Technology Data Exchange (ETDEWEB)

Reistad, G.M.; Means, P.

1980-05-01

A study of the performance and availability of water-source heat pumps was carried out. The primary purposes were to obtain the necessary basic information required for proper evaluation of the role of water-source heat pumps in geothermal energy utilization and/or to identify the research needed to provide this information. The Search of Relevant Literature considers the historical background, applications, achieved and projected performance evaluations and performance improvement techniques. The commercial water-source heat pump industry is considered in regard to both the present and projected availability and performance of units. Performance evaluations are made for units that use standard components but are redesigned for use in geothermal heating.

Urban district heating using nuclear heat - a survey

International Nuclear Information System (INIS)

Beresovski, T.; Oliker, I.

1979-01-01

The use of heat from nuclear power plants is of great interest in connection with projected future expansions of large urban district heating systems. Oil price escalation and air pollution from increased burning of fossil fuels are substantial incentivers for the adoption of nuclear heat and power plants. The cost of the hot water piping system from the nuclear plant to the city is a major factor in determining the feasibility of using nuclear heat. To achieve reasonable costs, the heat load should be at least 1500 MW(th), transport temperatures 125-200 0 C and distances preferably 50 km or less. Heat may be extracted from the turbines of conventional power reactors. Alternatively, some special-purpose smaller reactors are under development which are specially suited to production of heat with little or no power coproduct. Many countries are conducting studies of future expansions of district heating systems to use nuclear heat. Several countries are developing technology suitable for this application. Actual experience with the use of nuclear heat for district heating is currently being gained only in the USSR, however. While district heating appears to be a desirable technology at a time of increasing fossil-fuel costs, the use of nuclear heat will require siting of nuclear plants within transmission radius of cities. The institutional barries toward use of nuclear heating will have to be overcome before the energy conservation potential of this approach can be realized on a significant scale. (author)

Direct utilization of geothermal energy

International Nuclear Information System (INIS)

Lund, J. W.

2010-01-01

The worldwide application of geothermal energy for direct utilization is reviewed. This paper is based on the world update for direct-use presented at the World Geothermal Congress 2010 in Bali, Indonesia (WGC2010) which also includes material presented at three world geothermal congresses in Italy, Japan and Turkey (WGC95, WGC2000 and WGC2005). This report is based on country update papers prepared for WGC2010 and data from other sources. Final update papers were received from 70 countries of which 66 reported some direct utilization of geothermal energy for WGC2010. Twelve additional countries were added to the list based on other sources of information. The 78 countries having direct utilization of geothermal energy, is a significant increase from the 72 reported in 2005, the 58 reported in 2000, and the 28 reported in 1995. An estimate of the installed thermal power for direct utilization at the end of 2009, reported from WGC2010 is 48,493 MW th , almost a 72 % increased over the 2005 data, growing at a compound rate of 11.4% annually with a capacity factor of 0.28. The thermal energy used is 423,830 TJ/year (117,740 GWh/yr), about a 55% increase over 2005, growing at a compound rate of 9.2% annually. The distribution of thermal energy used by category is approximately 47.2% for ground-source heat pumps, 25.8% for bathing and swimming (including balneology), 14.9% for space heating (of which 85% is for district heating), 5.5% for greenhouses and open ground heating, 2.8% for industrial process heating, 2.7% for aquaculture pond and raceway heating, 0.4% for agricultural drying, 0.5% for snow melting and cooling, and 0.2% for other uses. Energy savings amounted to 250 million barrels (38 million tonnes) of equivalent oil annually, preventing 33 million tonnes of carbon and 107 million tonnes of CO 2 being released to the atmosphere which includes savings in geothermal heat pump cooling (compared to using fuel oil to generate electricity). (author)

Direct Utilization of Geothermal Energy

Directory of Open Access Journals (Sweden)

John W. Lund

2010-08-01

Full Text Available The worldwide application of geothermal energy for direct utilization is reviewed. This paper is based on the world update for direct-use presented at the World Geothermal Congress 2010 in Bali, Indonesia (WGC2010 [1] which also includes material presented at three world geothermal congresses in Italy, Japan and Turkey (WGC95, WGC2000 and WGC2005. This report is based on country update papers prepared for WGC2010 and data from other sources. Final update papers were received from 70 countries of which 66 reported some direct utilization of geothermal energy for WGC2010. Twelve additional countries were added to the list based on other sources of information. The 78 countries having direct utilization of geothermal energy, is a significant increase from the 72 reported in 2005, the 58 reported in 2000, and the 28 reported in 1995. An estimate of the installed thermal power for direct utilization at the end of 2009, reported from WGC2010 is 48,493 MWt, almost a 72 % increased over the 2005 data, growing at a compound rate of 11.4% annually with a capacity factor of 0.28. The thermal energy used is 423,830 TJ/year (117,740 GWh/yr, about a 55% increase over 2005, growing at a compound rate of 9.2% annually. The distribution of thermal energy used by category is approximately 47.2% for ground-source heat pumps, 25.8% for bathing and swimming (including balneology, 14.9% for space heating (of which 85% is for district heating, 5.5% for greenhouses and open ground heating, 2.8% for industrial process heating, 2.7% for aquaculture pond and raceway heating, 0.4% for agricultural drying, 0.5% for snow melting and cooling, and 0.2% for other uses. Energy savings amounted to 250 million barrels (38 million tonnes of equivalent oil annually, preventing 33 million tonnes of carbon and 107 million tonnes of CO2 being release to the atmosphere which includes savings in geothermal heat pump cooling (compared to using fuel oil to generate electricity.

Current state of exploitation of low enthalpy geothermal energy in France

International Nuclear Information System (INIS)

Boisdet, A.; Fouillac, C.; Jaudin, F.; Menjoz, A.; Rojas, J.; Ferrandes, R.; Lemale, J.

1990-01-01

This paper reports that at present, the geothermal exploitation in France is characterized by sixty plants using geothermal energy for direct heat in district heating. Drilling and connection to networks occurred mainly during the years 1980-1985. From 1985 to 1990, the research efforts have been focused on detailed reservoir knowledge, corrosion-scaling process induced by the fluid composition, methods and techniques for maintenance, rehabilitation of some wells and equipments after work over. Concentrated in two main area, the Paris and Aquitaine basins, the French geothermal potential is large. The improved knowledge obtained during the last five years spared to the valorization of existing plants will allow a new start of geothermal exploitation. Nevertheless this latter is highly dependent on the international energy context

The state of exploitation of geothermal energy and some interesting achievements in geothermal research and development in the world

Directory of Open Access Journals (Sweden)

Dušan Rajver

2016-08-01

Full Text Available The article presents the latest status of geothermal energy use worldwide and the comparison with the previous period, both in electricity generation as well as in the various categories of direct use. Electricity production takes place in 26 countries and has at the end of 2014 reached 73,700 GWh from geothermal power plants with nearly 12.8 GW of installed power. This is still only 0.31 % of the total electricity produced in the world and it will be interesting to monitor the future share of geothermal energy in doing so. In the last 5-year period the development was particularly rapid in countries where it was slower in the past and, however, with favorable geological (tectonic conditions (Iceland, Kenya, New Zealand, Turkey, etc.. Direct use of geothermal energy covers a signifiant number of countries, today there are 82, although some of them are such where it takes place almost solely by geothermal (ground-source heat pumps (GHP on shallow subsurface energy (Finland. Installed capacity in the direct use is 70,885 MWt and geothermal energy used, including the GHP, is 592,638 TJ/year (end of 2014. Within the used energy the share of GHP dominates with 55.2 %, followed by the bathing and swimming pools complexes incl. balneology by 20.2 %, space heating by 15.0 % (the majority of it is district heating, heating of greenhouses and soil with 4.9 %, etc. The second part presents some interesting technological and scientifi innovations in exploration and exploitation of geothermal energy.

Geochemical Study of Ampallas Geothermal Area, Mamuju District, West Sulawesi Province

Science.gov (United States)

Fauziyyah, F.; Prabowo, T. R.; Shalihin, M. G. J.; Setiawan, D. I.; Yushantarti, A.

2016-09-01

Ampallas is one of the areas with geothermal potential which located in Mamuju district, near from the capital city of West Sulawesi. This research was carried out to understand the characteristic of this geothermal field based on chemistry of the surface manifestation, including fluid characteristic and soil anomaly. Geothermal research in Ampallas area focused on 4 hot springs; Ampallas, Batupane, Karema, and Gantungan. With average temperature around 34 - 67°C. Ampallas 1,2,3,4,7,8 hot springs water type is chloride - bicarbonate, which means it came from the reservoir while Batupane, Gantungan, Karema and Ampallas 5 are all bicarbonate type. Ampallas 1,2,3,4,7,8, Karema and Gantungan hot springs fluid plotted in partial equilibrium zone while Batupane and Ampallas 5 plotted in immature water zone. It means the Ampallas hot springs (except Ampallas-5) mixed with meteoric water right after reached the equilibrium state. It is also concluded that Ampallas 5 hot springs came from the same reservoir with Batupane, but not Gantungan and Karema hot springs. The speculative resource potential of Ampallas geothermal system is estimated around 30 MWe. But if detailed geophysical method was applied the result could be more accurate.

Future Services for District Heating Solutions in Residential Districts

Directory of Open Access Journals (Sweden)

Hannele Ahvenniemi

2014-06-01

Full Text Available The underlying assumption of this study is that in order to retain the competitiveness while reaching for the EU targets regarding low-energy construction, district heating companies need to develop new business and service models. How district heating companies could broaden their perspective and switch to a more service-oriented way of thinking is a key interest of our research. The used methods in our study are house builder interviews and a questionnaire. With the help of these methods we discussed the potential interest in heating related services acquiring a comprehensive understanding of the customer needs. The results indicate the importance of certain criteria when choosing the heating system in households: easiness, comfort and affordability seem to dominate the house builders’ preferences. Also environmental awareness seems to be for many an important factor when making a decision about the heating of the house. Altogether, based on the results of this study, we suggest that the prospects of district heating could benefit from highlighting certain aspects and strengths in the future. District heating companies need to increase flexibility, readiness to adopt new services, to invest in new marketing strategies and improving the communication skills.

Research report on promotion of geothermal energy exploitation for fiscal 1997. Fluid geochemical research (No.B-6 Tsujinodake district); 1997 nendo chinetsu kaihatsu sokushin chosa. Ryutai chikagaku chosa hokokusho (No.B-6 Tsujinodake chiiki)

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

The research covers the Tsujinodake district spreading over Yamakawa-cho and Ibusuki-shi, Kagoshima Prefecture. Hot spring water in the district is of the neutral Cl type, heated mainly by conduction and containing seawater. The thermal water layer of the highest geothermal potential exists in the vicinity of the Nishi district of Ibusuki-shi. It spreads widely in the westward part and may be linked with the Unagiike district. The temperature of the deep-seated thermal water layer is estimated at 220-230 degrees C, yet it may be higher. In addition to the layer in the vicinity of the Nishi and Unagiike districts, there is a shallow-seated hot spring aquifer in the Nagasakibana district, where the deep-seated thermal water is probably prevented from lifting in the presence of an aquiclude. In the Narikawa district, possibilities are low that the thermal water just beneath will come up. As for hot spring water in the Oyama and Okachogamizu districts, there are no signs of high-temperature thermal water infiltration. In these two districts, it appears that hot spring water is heated by conduction over a large area. For the disclosure of linkage of hot water systems and deep-seated geothermal structures which cannot be detected by geochemical investigations conducted into hot spring water, etc., it is necessary to resort to geological and geophysical researches, and to carry out test drilling. (NEDO)

Integrated multiscale simulation of combined heat and power based district heating system

International Nuclear Information System (INIS)

Li, Peifeng; Nord, Natasa; Ertesvåg, Ivar Ståle; Ge, Zhihua; Yang, Zhiping; Yang, Yongping

2015-01-01

Highlights: • Simulation of power plant, district heating network and heat users in detail and integrated. • Coupled calculation and analysis of the heat and pressure losses of the district heating network. • District heating is not preferable for very low heat load due to relatively high heat loss. • Lower design supply temperatures of the district heating network give higher system efficiency. - Abstract: Many studies have been carried out separately on combined heat and power and district heating. However, little work has been done considering the heat source, the district heating network and the heat users simultaneously, especially when it comes to the heating system with large-scale combined heat and power plant. For the purpose of energy conservation, it is very important to know well the system performance of the integrated heating system from the very primary fuel input to the terminal heat users. This paper set up a model of 300 MW electric power rated air-cooled combined heat and power plant using Ebsilon software, which was validated according to the design data from the turbine manufacturer. Then, the model of heating network and heat users were developed based on the fundamental theories of fluid mechanics and heat transfer. Finally the combined heat and power based district heating system was obtained and the system performances within multiscale scope of the system were analyzed using the developed Ebsilon model. Topics with regard to the heat loss, the pressure drop, the pump power consumption and the supply temperatures of the district heating network were discussed. Besides, the operational issues of the integrated system were also researched. Several useful conclusions were drawn. It was found that a lower design primary supply temperature of the district heating network would give a higher seasonal energy efficiency of the integrated system throughout the whole heating season. Moreover, it was not always right to relate low design

Low-cost low-enthalpy geothermal heat for freshwater production: Innovative applications using thermal desalination processes

KAUST Repository

Bundschuh, Jochen; Ghaffour, NorEddine; Mahmoudi, Hacè ne; Goosen, Mattheus F A; Mushtaq, Shahbaz; Hoinkis, Jan

2015-01-01

The study is dedicated to exploring different types of low-cost low-enthalpy geothermal and their potential integration with conventional thermal-based water desalination and treatment technologies to deliver energy efficient, environmentally friendly solutions for water desalination and treatment, addressing global water crises. Our in-depth investigation through reviews of various low-enthalpy geothermal and conventional thermal-based technologies suggest that the geothermal option is superior to the solar option if low-cost geothermal heat is available because it provides a constant heat source in contrast to solar. Importantly, the stable heat source further allows up-scaling (> 1000 m3/day), which is not currently possible with solar. Solar-geothermal hybrid constellations may also be suitable in areas where both sources are available. The review also discovers that the innovative Membrane distillation (MD) process is very promising as it can be used for many different water compositions, salinity and temperature ranges. Either the geothermal water itself can be desalinated/treated or the geothermal heat can be used to heat feed water from other sources using heat exchangers. However, there are only few economic analyses for large-scale MD units and these are based on theoretical models using often uncertain assumptions resulting in a large variety of results.

Low-cost low-enthalpy geothermal heat for freshwater production: Innovative applications using thermal desalination processes

KAUST Repository

Bundschuh, Jochen

2015-03-01

The study is dedicated to exploring different types of low-cost low-enthalpy geothermal and their potential integration with conventional thermal-based water desalination and treatment technologies to deliver energy efficient, environmentally friendly solutions for water desalination and treatment, addressing global water crises. Our in-depth investigation through reviews of various low-enthalpy geothermal and conventional thermal-based technologies suggest that the geothermal option is superior to the solar option if low-cost geothermal heat is available because it provides a constant heat source in contrast to solar. Importantly, the stable heat source further allows up-scaling (> 1000 m3/day), which is not currently possible with solar. Solar-geothermal hybrid constellations may also be suitable in areas where both sources are available. The review also discovers that the innovative Membrane distillation (MD) process is very promising as it can be used for many different water compositions, salinity and temperature ranges. Either the geothermal water itself can be desalinated/treated or the geothermal heat can be used to heat feed water from other sources using heat exchangers. However, there are only few economic analyses for large-scale MD units and these are based on theoretical models using often uncertain assumptions resulting in a large variety of results.

District Heating Expansion Potential with Low-Temperature and End-Use Heat Savings

DEFF Research Database (Denmark)

Nielsen, Steffen; Grundahl, Lars

2018-01-01

District heating has the potential to play a key role in the transition towards a renewable energy system. However, the development towards reduced heat demands threatens the feasibility of district heating. Despite this challenge, opportunity exists in the form of fourth generation district...... heating, which operates at lower temperatures and enables better renewable integration. This article investigates this challenge by examining the district heating potential within three scenarios: The first is a reference scenario with current heat demand and temperatures, the second includes heat demand...... costs. The models are applied using an example case of The Northern Region of Denmark. The article concludes that the district heating potential is highest in the reference scenario. When heat savings are introduced, district heating expansions, in most cases, will not be feasible. Introducing low...

High geothermal heat flux measured below the West Antarctic Ice Sheet.

Science.gov (United States)

Fisher, Andrew T; Mankoff, Kenneth D; Tulaczyk, Slawek M; Tyler, Scott W; Foley, Neil

2015-07-01

The geothermal heat flux is a critical thermal boundary condition that influences the melting, flow, and mass balance of ice sheets, but measurements of this parameter are difficult to make in ice-covered regions. We report the first direct measurement of geothermal heat flux into the base of the West Antarctic Ice Sheet (WAIS), below Subglacial Lake Whillans, determined from the thermal gradient and the thermal conductivity of sediment under the lake. The heat flux at this site is 285 ± 80 mW/m(2), significantly higher than the continental and regional averages estimated for this site using regional geophysical and glaciological models. Independent temperature measurements in the ice indicate an upward heat flux through the WAIS of 105 ± 13 mW/m(2). The difference between these heat flux values could contribute to basal melting and/or be advected from Subglacial Lake Whillans by flowing water. The high geothermal heat flux may help to explain why ice streams and subglacial lakes are so abundant and dynamic in this region.

High geothermal heat flux measured below the West Antarctic Ice Sheet

Science.gov (United States)

Fisher, Andrew T.; Mankoff, Kenneth D.; Tulaczyk, Slawek M.; Tyler, Scott W.; Foley, Neil

2015-01-01

The geothermal heat flux is a critical thermal boundary condition that influences the melting, flow, and mass balance of ice sheets, but measurements of this parameter are difficult to make in ice-covered regions. We report the first direct measurement of geothermal heat flux into the base of the West Antarctic Ice Sheet (WAIS), below Subglacial Lake Whillans, determined from the thermal gradient and the thermal conductivity of sediment under the lake. The heat flux at this site is 285 ± 80 mW/m2, significantly higher than the continental and regional averages estimated for this site using regional geophysical and glaciological models. Independent temperature measurements in the ice indicate an upward heat flux through the WAIS of 105 ± 13 mW/m2. The difference between these heat flux values could contribute to basal melting and/or be advected from Subglacial Lake Whillans by flowing water. The high geothermal heat flux may help to explain why ice streams and subglacial lakes are so abundant and dynamic in this region. PMID:26601210

The possibilities of utilisation of heat from Tattapani Geothermal field, India

Energy Technology Data Exchange (ETDEWEB)

Sarolkar, P.B. [Geological Survey of India, Hyderabad (India); Pitale, U.L. [Geological Survey of India, Nagpur (India)

1996-12-31

The Tattapani Geothermal field produces + 1800 1pm thermal water of 100{degrees}C from five production wells. The hot water production can sustain electricity production of 300 kWe by using a binary cycle power plant. The heat energy of effluent water from power plant can be utilized for direct heat utilization on horticulture, aquaculture, cold storage, silviculture etc; to augment the economics of the power plant be spot can be developed as a centre for tourist attraction by constructing botanical park, greenhouse, geyser show and crocodile farm. The direct heat utilization shemes can be planned in cascading order to achieve maximum utility of thermal water. Additional deep drilling is essential for optimum commercial utilization of the Geothermal energy. The direct heat utilisation shemes along with binary cycle power plant may help in development of the geothermal energy and boosting the economy of this region.

Update on Geothermal Direct-Use Installations in the United States

Energy Technology Data Exchange (ETDEWEB)

Beckers, Koenraad J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Young, Katherine R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Snyder, Diana M. [Georgia State University

2017-02-15

Direct-use of geothermal energy currently has limited penetration in the United States, with an estimated installed capacity of about 500 MWth, supplying on the order of 0.01% of the total annual U.S. heat demand (about 30 EJ). We see higher penetration levels in other countries such as Iceland (about 90%) and Hungary (2.5%). An updated database of geothermal direct-use systems in the U.S. has been compiled and analyzed, building upon the Oregon Institute of Technology (OIT) Geo-Heat Center direct-use database. Types of directuse applications examined include hot springs resorts and pools, aquaculture farms, greenhouses, and district heating systems, among others; power-generating facilities and ground-source heat pumps were excluded. Where possible, the current operation status, open and close dates, well data, and other technical data were obtained for each entry. The database contains 545 installations, of which 407 are open, 108 are closed, and 30 have an unknown status. Spas are the most common type of installation, accounting for 50% of installations by number. Aquaculture installations (46 out of 407 open installations) account for the largest percentage (26%) of installed capacity in operation (129 MWth out of 501 MWth). Historical deployment curves show the installed capacity significantly increased in the 1970s and 1980s mainly due to development of geothermal district heating, aquaculture, and greenhouse systems. Since the 2000s, geothermal direct-use development appears to have slowed, and the number of sites in operation decreased due to closures. Case studies reveal multiple barriers to geothermal direct-use implementation and operation, including 1) existence of an information gap among stakeholders, developers, and the general public, 2) competition from cheap natural gas, and 3) the family-owned, small-scale nature of businesses might result in discontinuation among generations.

Mapping of potential heat sources for heat pumps for district heating in Denmark

International Nuclear Information System (INIS)

Lund, Rasmus; Persson, Urban

2016-01-01

The ambitious policy in Denmark on having a 100% renewable energy supply in 2050 requires radical changes to the energy systems to avoid an extensive and unsustainable use of biomass resources. Currently, wind power is being expanded and the increasing supply of electricity is slowly pushing the CHP (combined heat and power) plants out of operation, reducing the energy efficiency of the DH (district heating) supply. Here, large heat pumps for district heating is a frequently mentioned solution as a flexible demand for electricity and an energy efficient heat producer. The idea is to make heat pump use a low temperature waste or ambient heat source, but it has so far been very unclear which heat sources are actually available for this purpose. In this study eight categories of heat sources are analysed for the case of Denmark and included in a detailed spatial analysis where the identified heat sources are put in relation to the district heating areas and the corresponding demands. The analysis shows that potential heat sources are present near almost all district heating areas and that sea water most likely will have to play a substantial role as a heat source in future energy systems in Denmark. - Highlights: • The availability of heat sources for heat pumps in Denmark are mapped and quantified. • A novel methodology for assessment of low temperature industrial excess heat is presented. • There are heat sources available for 99% of district heating networks in Denmark. • The concentration of heat sources is generally bigger around bigger cities than smaller. • Ambient temperature heat sources will be more needed in district heating of big cities.

Hot Topics! Heat Pumps and Geothermal Energy

Science.gov (United States)

Roman, Harry T.

2009-01-01

The recent rapid rises in the cost of energy has significantly increased interest in alternative energy sources. The author discusses the underlying principles of heat pumps and geothermal energy. Related activities for technology education students are included.

Shortage of energy increases profitability of district heating

International Nuclear Information System (INIS)

2003-01-01

Increased demand will cause the price of district heating to increase, but not to the level of the price of electricity. The cheapest heating alternative in Denmark, Norway and Sweden is district heating. In Norway, district heating is developed primarily for commercial buildings and housing cooperatives. Thirty per cent of all buildings under construction are prepared for district heating and the percentage will increase strongly in the coming time. The total net production of district heating in Norway in 2001 was 2000 GWh, which is only a small part of the total potential for district heating

District heating in Flensburg

Energy Technology Data Exchange (ETDEWEB)

Prinz, W.

1981-01-01

The majority of our population, but also of our authorities, are still skeptical or even disapproving towards district heating. The reasons of this negative attitude are partly psychological - e.g. the individualism of the Swiss and their dislike for too centralised structures and ''forced connections'' - but also the existence of finished gas supply networks and the fear of considerable pre-investments and torn streets over years. The following article - held as a speech on the information meeting ''District heating and the possible contribution of nuclear energy'' organised by the Swiss Association for Atomic Energy in Bern shows a practical problem solving at the example of the district heating in Flensburg and deals with these questions.

Dynamic modeling of а heating system using geothermal energy and storage tank

Directory of Open Access Journals (Sweden)

Milanović Predrag D.

2012-01-01

Full Text Available This paper analyzes a greenhouse heating system using geothermal energy and storage tank and the possibility of utilization of insufficient amount of heat from geothermal sources during the periods with low outside air temperatures. Crucial for these analyses is modelling of the necessary yearly energy requirements for greenhouse heating. The results of these analyses enable calculation of an appropriate storage tank capacity so that the energy efficiency of greenhouse heating system with geothermal energy could be significantly improved. [Acknowledgement. This work was supported by Ministry of Science and Technology Development of the Republic of Serbia through the National Energy Efficiency Program (Grant 18234 A. The authors are thankful to the stuff and management of the Company “Farmakom MB PIK 7. juli - Debrc” for their assistance during the realization of this project.

The state of the Canadian geothermal heat pump industry 2010 : industry survey and market analysis

International Nuclear Information System (INIS)

2010-11-01

This report provided an overview of the state of the Canadian geothermal heat pump industry for 2010. In 2003, the Canadian GeoExchange Coalition (CGC) embarked on a market transformation initiative that continues to shape Canada's geothermal heat pump markets. The market for ground source heat pumps has grown by more than 60 percent annually in 2006, 2007, and 2008. The large increases in oil prices has created a price effect strong enough to trigger fuel switching for many consumers. Growth in the industry has also coincided with grant and financial assistance programs deployed by provincial governments, utilities, and the federal government. The ecoENERGY retrofitting program initiated in 2007 encouraged the use of geothermal heat pumps in the residential retrofit market. Tax rebate and load programs, as well as direct grants from provincial governments have increased demand in the new-built market. Canada's geothermal heat pump markets are growing much faster than United States geothermal markets. Closed horizontal loop systems accounted for 49.4 percent of residential installations. The CGC has trained over 2968 installers as well as many designers and inspectors for geothermal heat pumps. Colleges and public institutions are now creating training programs related to geothermal energy use. The total economic activity of the geoexchange industry in 2009 was estimated at in excess of $500 million. 29 tabs., 63 figs.

Experimental evaluation of a non-azeotropic working fluid for geothermal heat pump system

International Nuclear Information System (INIS)

Zhao, L.

2004-01-01

Geothermal energy resources are found in many countries. A reasonable and efficient utilization of these resources has been a worldwide concern. The application of geothermal heat pump systems (GHPS) can help increase the efficiency of using geothermal energy and reduce the thermal pollution to the earth surface. However, this is only possible with a proper working fluid. In this paper, a non-azeotropic working fluid (R290/R600a/R123) is presented for a GHPS where geothermal water at 40-45 deg. C and heating network water at 70-80 deg. C serve as the low and high temperature heat sources. Experimental results show that the coefficient of performance (COP) of a GHPS using the working fluid is above 3.5 with the condensation temperature above 80 deg. C and the condensation pressure below 18 bar, while the temperature of the geothermal water is reduced from 40-46 deg. C to 31-36 deg. C

Thermodynamic and economic evaluations of a geothermal district heating system using advanced exergy-based methods

International Nuclear Information System (INIS)

Tan, Mehmet; Keçebaş, Ali

2014-01-01

Highlights: • Evaluation of a GDHS using advanced exergy-based methods. • Comparison of the results of the conventional and advanced exergy-based methods. • The modified exergetic efficiency and exergoeconomic factor are found as 45% and 13%. • Improvement and total cost-savings potentials are found to be 3% and 14%. • All the pumps have the highest improvement potential and total cost-savings potential. - Abstract: In this paper, a geothermal district heating system (GDHS) is comparatively evaluated in terms of thermodynamic and economic aspects using advanced exergy-based methods to identify the potential for improvement, the interactions among system components, and the direction and potential for energy savings. The actual operational data are taken from the Sarayköy GDHS, Turkey. In the advanced exergetic and exergoeconomic analyses, the exergy destruction and the total operating cost within each component of the system are split into endogenous/exogenous and unavoidable/avoidable parts. The advantages of these analyses over conventional ones are demonstrated. The results indicate that the advanced exergy-based method is a more meaningful and effective tool than the conventional one for system performance evaluation. The exergetic efficiency and the exergoeconomic factor of the overall system for the Sarayköy GDHS were determined to be 43.72% and 5.25% according to the conventional tools and 45.06% and 12.98% according to the advanced tools. The improvement potential and the total cost-savings potential of the overall system were also determined to be 2.98% and 14.05%, respectively. All of the pumps have the highest improvement potential and total cost-savings potential because the pumps were selected to have high power during installation at the Sarayköy GDHS

Geothermal heat for Erding. 2. Energy and wellness, geothermal heating station and hot-water indoor swimming pool; Geowaerme fuer Erding 2. Energie und Wellness, Geothermieheizwerk und Thermalbad

Energy Technology Data Exchange (ETDEWEB)

Tenzer, H. (comp.); Bussmann, W.

1999-07-01

This 17:20 minute VHS-PAL video film describes the project 'Geothermal heat for Erding 2', i.e. the construction of the geothermal heating station and a modern hot-water indoor swimming pool. [German] Der vorliegende VHS-PAL-Videofilm beschreibt innerhalb von 17:20 Min. Lauflaenge das Projekt 'Geowaerme fuer Erding 2'. Gezeigt werden die Entstehungsphasen dieses Projektes bestehend aus einem Geothermieheizwerk und einem modernen Thermalbad. (AKF)

Geothermal studies in oilfield districts of Eastern Margin of the Gulf of Suez, Egypt

Directory of Open Access Journals (Sweden)

Mohamed Abdel Zaher

2014-06-01

Full Text Available Results of geothermal studies carried out at 149 onshore oil wells have been used in evaluation of temperature gradient and heat flow values of the eastern shore of the Gulf of Suez. The investigations included temperature logs in boreholes, calculation of amplitude temperature, geothermal gradients and heat flow. The results obtained indicate that geothermal gradient values are in the ranges of 0.02–0.044 °C/m and regionally averaged mean heat flow values are found to fall in the interval of 45–120 mW/m2. Temperature gradients and heat flow values change from low values eastward to high values toward the axial of Gulf of Suez rift. The result of this research work has been highly successful in identifying new geothermal resources eastward of the Gulf of Suez. Additionally, this study shows that the areas with relatively higher temperature gradients have lower oil window, mature earlier, than those with low gradient values. Thus, high temperature gradients cause to expedite the formation of oil at relatively shallow depths and narrow oil windows. On the other hand, low temperature gradient makes the oil window to be quite broad when locate at high depths.

A good year for district heating

International Nuclear Information System (INIS)

Bakken, Stein Arne

2003-01-01

In Norway, high prices on electric power have caused economic progress for the district heating companies. The price of district heating is determined by the prices of power and fuel oil. However, the government wants to remove the tax on electricity to the industry, which is the district heating companies' major group of customers, along with public buildings. This is likely to entail a great loss of income

The Marsili Volcanic Seamount (Southern Tyrrhenian Sea: A Potential Offshore Geothermal Resource

Directory of Open Access Journals (Sweden)

Francesco Italiano

2014-06-01

Full Text Available Italy has a strong geothermal potential for power generation, although, at present, the only two geothermal fields being exploited are Larderello-Travale/Radicondoli and Mt. Amiata in the Tyrrhenian pre-Apennine volcanic district of Southern Tuscany. A new target for geothermal exploration and exploitation in Italy is represented by the Southern Tyrrhenian submarine volcanic district, a geologically young basin (Upper Pliocene-Pleistocene characterised by tectonic extension where many seamounts have developed. Heat-flow data from that area show significant anomalies comparable to those of onshore geothermal fields. Fractured basaltic rocks facilitate seawater infiltration and circulation of hot water chemically altered by rock/water interactions, as shown by the widespread presence of hydrothermal deposits. The persistence of active hydrothermal activity is consistently shown by many different sources of evidence, including: heat-flow data, gravity and magnetic anomalies, widespread presence of hydrothermal-derived gases (CO2, CO, CH4, 3He/4He isotopic ratios, as well as broadband OBS/H seismological information, which demonstrates persistence of volcano-tectonic events and High Frequency Tremor (HFT. The Marsili and Tyrrhenian seamounts are thus an important—and likely long-lasting-renewable energy resource. This raises the possibility of future development of the world’s first offshore geothermal power plant.

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

Geothermal long-term modelling of a solar coupled geothermal probe heat storage in Crailsheim; Geothermische Langzeitmodellierung eines solargekoppelten Erdsonden-Waermespeichers in Crailsheim

Energy Technology Data Exchange (ETDEWEB)

Homuth, Sebastian; Mikisek, Philipp; Goetz, Annette E.; Sass, Ingo [Technische Univ. Darmstadt (Germany). Fachgebiet Angewandte Geothermie

2011-10-24

The thermal variations of the subsurface in the vicinity of a seasonal solar coupled geothermal probe heat storage were modeled using FEFLOW {sup registered} over a period of thirty years. The geothermal probe heat storage consists of eighty boreholes in an area of 85 square meters. The geothermal probes have a depth of 55 m and are mainly located in limestones of the Upper Muschelkalk (Triassic). The geothermal probe heat storage is thermally loaded from April to September. The thermal discharge takes place from October to March. The thermal and hydraulic input data of the model are based on three 80 meter deep geothermal probes (GWM 1-3) in the vicinity of the storage. The cores were completely lithologically, facially and finely stratigraphically affiliated. Measurements of thermal conductivity, permeability, porosity and density of 76 representative samples from the geothermal probe GWM 3 and measurements of the main fracture directions in two reference digestions at Crailsheim enabled a most realistic modeling of the storage. The results of the long-term modeling can be used for a detailed forecasting of the thermal alterations in the subsurface.

Distributed heat generation in a district heating system

OpenAIRE

Lennermo, Gunnar; Lauenberg, Patrick

2016-01-01

District heating (OH) systems need to be improved  regarding integration  of decentralised  heat generation. Micro production, prosumers and smart grids are terms becoming more and more common  in  connection  to  the  power  grid.  Concerning district  heating,  the  development  is slower, although improving. Today there are a number of such decentralised units for heat generation,  mainly  solar,  that have been partly evaluated.  Previous  studies  have shown  that there is a need to deve...

Exploration for geothermal resources in the Capital District of New York. Final report

Energy Technology Data Exchange (ETDEWEB)

Sneeringer, M.R.; Dunn, J.R.

1981-11-01

Water chemistry, gas analyses, and geophysical methods including gravity and magnetic surveys, microseismic monitoring, and temperature gradient measurements were used in the Capital District area to evaluate the potential for a hydrothermal geothermal system. Water and gas chemistries provided indirect indicators, and temperature gradients provided direct indications of a geothermal system. Gravity results were supportive of gradient and chemistry data, but seismic and magnetic work have thus far provided little information on the potential system. Gradients throughout the area ranged from an average background value of about 10/sup 0/C/km to a high of roughly 44/sup 0/C/km. The highest gradient values, the most unusual water chemistries and largest carbon dioxide exhalations occur along the Saratoga and McGregor faults between Saratoga Springs and Schenectady, and indicate a good potential for a usable hydrothermal geothermal system at depth.

Heat buffers improve capacity and exploitation degree of geothermal energy sources

NARCIS (Netherlands)

Ooster, A.van t; Wit, J. de; Janssen, E.G.O.N.; Ruigrok, J.

2008-01-01

This research focuses on the role of heat buffers to support optimal use of combinations of traditional and renewable heat sources like geothermal heat for greenhouse heating. The objective was to determine the contribution of heat buffers to effective new combinations of resources that satisfy

Optimization concept. Utilization of the geothermal resources in D. Podlog - Kochani, R. Macedonia

International Nuclear Information System (INIS)

Vasilevska-Popovska, Sanja; Popovski, Kiril

1999-01-01

The geothermal system 'Geoterma', near the town Kocani, located in the North-Eastern part of Macedonia, uses heat energy from the geothermal field of the Kocani Valley, which is one of the most important in the Europe. The exploitation of the geothermal resources started 1985/86 by KJP-Vodovod Geoterma. After the production of a cumulative quantity of more than 20 million m 3 thermal water for the purpose of direct heating (greenhouses, district heating), technical problems concerning the re-injection of used water occurred. In 1998 the technical co-operation between the Federal Chancellery of the Republic of Austria and Ministry of Economy of Republic of Macedonia was established to support the project, which will help to improve the technical and environmental situation. (Author)

Investigation of waste heat recovery of binary geothermal plants using single component refrigerants

Science.gov (United States)

Unverdi, M.

2017-08-01

In this study, the availability of waste heat in a power generating capacity of 47.4 MW in Germencik Geothermal Power Plant has been investigated via binary geothermal power plant. Refrigerant fluids of 7 different single components such as R-134a, R-152a, R-227ea, R-236fa, R-600, R-143m and R-161 have been selected. The binary cycle has been modeled using the waste heat equaling to mass flow rate of 100 kg/s geothermal fluid. While the inlet temperature of the geothermal fluid into the counter flow heat exchanger has been accepted as 110°C, the outlet temperature has been accepted as 70°C. The inlet conditions have been determined for the refrigerants to be used in the binary cycle. Finally, the mass flow rate of refrigerant fluid and of cooling water and pump power consumption and power generated in the turbine have been calculated for each inlet condition of the refrigerant. Additionally, in the binary cycle, energy and exergy efficiencies have been calculated for 7 refrigerants in the availability of waste heat. In the binary geothermal cycle, it has been found out that the highest exergy destruction for all refrigerants occurs in the heat exchanger. And the highest and lowest first and second law efficiencies has been obtained for R-600 and R-161 refrigerants, respectively.

Geothermal studies in oil field districts of North China

Science.gov (United States)

Wang, Ji-An; Wang, Ji-Yang; Yan, Shu-Zhen; Lu, Xiu-Wen

In North China, Tertiary sediments give the main oil-genetic series. The mean value of terrestrial heat flow density has been considered to be 60 - 65 mW/m2, and the geothermal gradient in Tertiary sediments usually ranges from 30 to 40° C/km in the region studied. Supposing that the onset of oil generation lies at about 90° C, the upper limit of the depth of oil-generation is at about 2000 to 2500 m depth. Recent paleogeothermal studies using vitrinite reflectance, clay and authigenic minerals, as well as other methods showed that in Eocene the geothermal gradient has been higher than at present. Some results were obtained and discussed.

Final Scientific/Technical Report [Recovery Act: Districtwide Geothermal Heating Conversion

Energy Technology Data Exchange (ETDEWEB)

Chatterton, Mike [McKinstry, Meridian, ID (United States)

2014-02-12

The Recovery Act: Districtwide Geothermal Heating Conversion project performed by the Blaine County School District was part of a larger effort by the District to reduce operating costs, address deferred maintenance items, and to improve the learning environment of the students. This project evaluated three options for the ground source which were Open-Loop Extraction/Re-injection wells, Closed-Loop Vertical Boreholes, and Closed-Loop Horizontal Slinky approaches. In the end the Closed-Loop Horizontal Slinky approach had the lowest total cost of ownership but the majority of the sites associated with this project did not have enough available ground area to install the system so the second lowest option was used (Open-Loop). In addition to the ground source, this project looked at ways to retrofit existing HVAC systems with new high efficiency systems. The end result was the installation of distributed waterto- air heat pumps with water-to-water heat pumps installed to act as boilers/chillers for areas with a high ventilation demand such as they gymnasiums. A number of options were evaluated and the lowest total cost of ownership approach was implemented in the majority of the facilities. The facilities where the lowest total cost of ownership approaches was not selected were done to maintain consistency of the systems from facility to facility. This project had a number of other benefits to the Blaine County public. The project utilizes guaranteed energy savings to justify the levy funds expended. The project also developed an educational dashboard that can be used in the classrooms and to educate the community on the project and its performance. In addition, the majority of the installation work was performed by contractors local to Blaine County which acted as an economic stimulus to the area during a period of recession.

Corrosion of copper alloys in sulphide containing district heting systems

DEFF Research Database (Denmark)

Thorarinsdottir, R.I.; Maahn, Ernst Emanuel

1999-01-01

Copper and some copper alloys are prone to corrosion in sulphide containing geothermal water analogous to corrosion observed in district heating systems containing sulphide due to sulphate reducing bacteria. In order to study the corrosion of copper alloys under practical conditions a test...... was carried out at four sites in the Reykjavik District Heating System. The geothermal water chemistry is different at each site. The corrosion rate and the amount and chemical composition of deposits on weight loss coupons of six different copper alloys are described after exposure of 12 and 18 months......, respectively. Some major differences in scaling composition and the degree of corrosion attack are observed between alloys and water types....

District heating

International Nuclear Information System (INIS)

Hansen, L.

1993-01-01

The environmental risks and uncertainties of a high-energy future are disturbing and give rise to several reservations concerning the use of fossil fuels. A number of technologies will help to reduce atmospheric pollution. In Denmark special importance is attached to the following: Energy conservation. Efficient energy conversion. Renewable energy sources. District heating, combined production of heat and power. Many agree that district heating (DH), produced by the traditional heat-only plant, and combined heat and power (CHP) have enormous potential when considering thermal efficiency and lowered environmental impacts: The basic technology of each is proven, it would be relatively simple to satisfy a substantial part of the energy demand, and their high efficiencies mean reduced pollution including greenhouse gas emissions. This is especially important in high population density areas - the obviously preferred sites for such energy generation. Compared with individual heating DH can provide a community with an operationally efficient and most often also an economically competitive heat supply. This is particularly true under the circumstances where the DH system is supplied from CHP plants. Their use results in very substantial improvements in overall efficiency. Further environmental improvements arise from the reduced air pollution obtainable in reasonably large CHP plants equipped with flue gas cleaning to remove particles, sulphur dioxide, and nitrogen acids. As a consequence of these considerations, DH plays an important role in fulfilling the space and water heating demand in many countries. This is especially the case in Denmark where this technology is utilised to a very great extent. Indeed, DH is one of the reasons why Denmark has relatively good air quality in the cities. (au)

Device for district heating with utilization of waste heat from power plants

International Nuclear Information System (INIS)

Korek, J.

1976-01-01

In order to utilize the waste heat developing in power plants - especially in nuclear power plants - the author suggests to lead the waste heat of the coolers for oil (which the bearings are lubricated with), hydrogen (which serves for the stator rotor-cooling), and the stator cooling water to the circulating district heating water and to arrange these heat exchangers one behind another or parallel to each other in the water circuit of the district heating system. The oil cooler of the engine transformer is also connected with the circulation of the district heating water. The runback water of the district heating network could thus be heated from approx. 40 0 C up to 65 0 C. (UA) [de

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

Influencing Swedish homeowners to adopt district heating system

Energy Technology Data Exchange (ETDEWEB)

Mahapatra, Krushna; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Akademigatan 1, 831 25 Oestersund (Sweden)

2009-02-15

Improved energy efficiency and greenhouse gas mitigation could be achieved by replacing resistance heaters with district heating system. In 2005, only about 8% of the Swedish detached houses had district heating system. The expansion of such systems largely depends on homeowners' adoption decisions. And, to motivate homeowners to adopt district heating, it is essential to understand their decision-making process. In this context, in June 2005 we carried out a questionnaire survey of about 700 homeowners who lived in the city of Oestersund in houses with resistance heaters (baseline survey). About 84% of the respondents did not intend to install a new heating system. Since then these homeowners were influenced by (a) an investment subsidy by the Swedish government to replace resistance heaters with district heating, a brine/water-based heat pump, or a biomass-based heating system and (b) a marketing campaign by the municipality-owned district heating company. This paper analyses how these two measures influenced about 78% of the homeowners to adopt the district heating system. For this purpose we carried out a follow-up survey of the same homeowners in December 2006 (resurvey). Results showed that the investment subsidy and the marketing campaign created a need among the homeowners to adopt a new heating system. The marketing campaign was successful in motivating them to adopt the district heating system. The marketing strategy by the district heating company corresponds to the results obtained in the baseline survey. (author)

Influencing Swedish homeowners to adopt district heating system

International Nuclear Information System (INIS)

Mahapatra, Krushna; Gustavsson, Leif

2009-01-01

Improved energy efficiency and greenhouse gas mitigation could be achieved by replacing resistance heaters with district heating system. In 2005, only about 8% of the Swedish detached houses had district heating system. The expansion of such systems largely depends on homeowners' adoption decisions. And, to motivate homeowners to adopt district heating, it is essential to understand their decision-making process. In this context, in June 2005 we carried out a questionnaire survey of about 700 homeowners who lived in the city of Ostersund in houses with resistance heaters (baseline survey). About 84% of the respondents did not intend to install a new heating system. Since then these homeowners were influenced by (a) an investment subsidy by the Swedish government to replace resistance heaters with district heating, a brine/water-based heat pump, or a biomass-based heating system and (b) a marketing campaign by the municipality-owned district heating company. This paper analyses how these two measures influenced about 78% of the homeowners to adopt the district heating system. For this purpose we carried out a follow-up survey of the same homeowners in December 2006 (resurvey). Results showed that the investment subsidy and the marketing campaign created a need among the homeowners to adopt a new heating system. The marketing campaign was successful in motivating them to adopt the district heating system. The marketing strategy by the district heating company corresponds to the results obtained in the baseline survey

Influencing Swedish homeowners to adopt district heating system

Energy Technology Data Exchange (ETDEWEB)

Mahapatra, Krushna; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Akademigatan 1, 831 25 Oestersund (Sweden)

2009-02-15

Improved energy efficiency and greenhouse gas mitigation could be achieved by replacing resistance heaters with district heating system. In 2005, only about 8% of the Swedish detached houses had district heating system. The expansion of such systems largely depends on homeowners' adoption decisions. And, to motivate homeowners to adopt district heating, it is essential to understand their decision-making process. In this context, in June 2005 we carried out a questionnaire survey of about 700 homeowners who lived in the city of Oestersund in houses with resistance heaters (baseline survey). About 84% of the respondents did not intend to install a new heating system. Since then these homeowners were influenced by (a) an investment subsidy by the Swedish government to replace resistance heaters with district heating, a brine/water-based heat pump, or a biomass-based heating system and (b) a marketing campaign by the municipality-owned district heating company. This paper analyses how these two measures influenced about 78% of the homeowners to adopt the district heating system. For this purpose we carried out a follow-up survey of the same homeowners in December 2006 (resurvey). Results showed that the investment subsidy and the marketing campaign created a need among the homeowners to adopt a new heating system. The marketing campaign was successful in motivating them to adopt the district heating system. The marketing strategy by the district heating company corresponds to the results obtained in the baseline survey. (author)

A survey of geothermal process heat applications in Guatemala: An engineering survey

Energy Technology Data Exchange (ETDEWEB)

Altseimer, J.H.; Edeskuty, F.J.

1988-08-01

This study investigates how process heat from Guatemala's geothermal energy resources can be developed to reduce Guatemala's costly importation of oil, create new employment by encouraging new industry, and reduce fuel costs for existing industry. This investigation was funded by the US Agency for International Development and carried out jointly by the Guatemalan Government and the Los Alamos National Laboratory. Two sites, Amatitlan and Zunil, are being developed geothermally. Amatitlan is in the better industrial area but Zunil's geothermal development is more advanced. The industry around Zunil is almost exclusively agricultural and the development of an agricultural processing plant (freezing, dehydration, and cold storage) using geothermal heat is recommended. Similar developments throughout the volcanic zones of Guatemala are possible. Later, when the field at Amatitlan has been further developed, an industrial park can be planned. Potential Amatitlan applications are the final stage of salt refining, a thermal power plant, hospital/hotel heating and cooling, steam curing of concrete blocks, production of alcohol from sugar cane, and production of polyethylene from ethanol. Other special developments such as water pumping for the city of Guatemala and the use of moderate-temperature geothermal fluids for localized power production are also possible. 12 refs., 13 figs., 14 tabs.

4th Generation District Heating (4GDH)

DEFF Research Database (Denmark)

Lund, Henrik; Werner, Sven; Wiltshire, Robin

2014-01-01

This paper defines the concept of 4th Generation District Heating (4GDH) including the relations to District Cooling and the concepts of smart energy and smart thermal grids. The motive is to identify the future challenges of reaching a future renewable non-fossil heat supply as part...... of the implementation of overall sustainable energy systems. The basic assumption is that district heating and cooling has an important role to play in future sustainable energy systems – including 100 percent renewable energy systems – but the present generation of district heating and cooling technologies will have...

Assets of geothermal energy for buildings: heating, cooling and domestic hot water

International Nuclear Information System (INIS)

2016-01-01

This publication first proposes a brief overview on the status, context and perspectives of geothermal energy in France by evoking the great number of heat pumps installed during the last decades and the choice made by public and private clients for this source of heating and cooling. While indicating how geothermal energy intervenes during a building project, this publication outlines that this energy is discrete and renewable, and that its technology is proven. Some examples are then evoked: use of geothermal energy for a public building in Saint-Malo, for estate projects near Paris, for a shopping centre in Roissy, and for office buildings

Dimensioning of Boreholes for Geothermal Heat Pumps

Directory of Open Access Journals (Sweden)

Ryška Jiøí

2004-09-01

Full Text Available The paper deals with determination of borehole depths for geothermal heat pumps. Basic formulae are stated for heat convection in rocks. Software EED 2.0 was used for calculation of borehole depth depending on different entering parameters. The crucial parameter is thermal conductivity of rocks. The thermal conductivity could be very variable for the same kind of rock. Therefore its in-situ determination by means of formation thermal conductivity testing is briefly described.

Geothermal energy - effective solutions for heating and cooling of buildings

International Nuclear Information System (INIS)

Veleska, Viktorija

2014-01-01

Energy and natural resources are essential prerequisites for the maintenance of the life and the development of human civilization. With the advancement of technology is more emphasis on energy efficiency and reducing carbon dioxide emissions. Energy efficiency is using less power without reducing the quality of life. Almost half of the energy used is devoted to buildings, including heating and cooling. Buildings are a major source of CO_2 emissions in the atmosphere. Reducing the impact of buildings on the environment and the development of renewable energy, energy solutions are key factor in terms of sustainable development. Energy and geothermal pumps posts represent effective solutions for large facilities for heating and cooling. Geothermal energy piles represent a system of pipes that circulate thermal fluid and embedded in earth, thus extracting heat from the bearing to satisfy the needs for heating and cooling. Experience has shown that this type of energy piles can save up to two thirds of the cost of conventional heating, while geothermal pump has the ability to low temperature resources (such as groundwater and earth) to extract energy and raise the higher level needed for heating buildings. Their implementation is supported by an active group of researchers working with industry to demonstrate the benefits of dual benefit performance at the foundations. Initiative for renewable heat and potential for further adoption of solutions with these technologies is rapidly expanding. The use of this source of energy has great potential due to environmental, economic and social benefits. (author)

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.

Method of extracting heat from dry geothermal reservoirs

Science.gov (United States)

Potter, R.M.; Robinson, E.S.; Smith, M.C.

1974-01-22

Hydraulic fracturing is used to interconnect two or more holes that penetrate a previously dry geothermal reservoir, and to produce within the reservoir a sufficiently large heat-transfer surface so that heat can be extracted from the reservoir at a usefully high rate by a fluid entering it through one hole and leaving it through another. Introduction of a fluid into the reservoir to remove heat from it and establishment of natural (unpumped) convective circulation through the reservoir to accomplish continuous heat removal are important and novel features of the method. (auth)

THE ASSESSMENT OF GEOTHERMAL POTENTIAL OF TURKEY BY MEANS OF HEAT FLOW ESTIMATION

Directory of Open Access Journals (Sweden)

UĞUR AKIN

2014-12-01

Full Text Available In this study, the heat flow distribution of Turkey was investigated in the interest ofexploring new geothermal fields in addition to known ones. For this purposes, thegeothermal gradient was estimated from the Curie point depth map obtained from airbornemagnetic data by means of power spectrum method. By multiplying geothermal gradientwith thermal conductivity values, the heat flow map of Turkey was obtained. The averagevalue in the heat flow map of Turkey was determined as 74 mW/m2. It points out existenceof resources of geothermal energy larger than the average of the world resources. in termsof geothermal potential, the most significant region of Turkey is the Aydin and itssurrounding with a value exceeding 200 mW/m2. On the contrary, the value decreasesbelow 30 mW/m2in the region bordered by Aksaray, Niğde, Karaman and Konya. Thenecessity of conducting a detailed additional studies for East Black sea, East and SoutheastAnatolia is also revealed

Swedish district heating - owners, prices and profitability

International Nuclear Information System (INIS)

Andersson, Sofie; Werner, S.

2001-01-01

Owners, prices and profitability are examined in this report for 152 Swedish district heating companies during 1999. Only public information available has been used: Prices from a national annual consumer study, energy supplied, lengths of district heating pipes installed, and average prices for energy supplied. These companies are responsible for 96 % of all district heat supplied in Sweden. District heating systems owned by municipalities were responsible for 65 % of all district heat supply, while the share of power companies was 34 %. Other private owners accounted for 1 %. Only 12 % of the board members are women and more than 40 % of the companies have no woman in the board. The prices gathered by the annual consumer study are good estimates of the price level of district heating in Sweden. The average revenues are only 4,1 % lower than the effective average of prices gathered. Price of district heating decrease with size and market share. Use of combined heat and power plants decrease prices slightly. Lower prices with size can mainly be explained by lower energy supply costs. Calculated rates of return in relation to calculated replacement values increase slightly by size and are almost independent of age and market share. The purport of these conclusions is that the district heating companies share the cost reduction from size with their customers, while the whole benefit from high market shares is repaid to the customers. Calculated rates of return vary among the owner groups examined. Lower rates are accepted by municipalities, while power companies have higher rates at the average costs used. Total replacement costs for the 152 companies has been estimated to 89 billion Swedish crowns or 10 billion Euro. Only correlation analyses using one dimension have been used in this study. A higher degree of quality can be obtained by using multi-dimensional analyses

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.

A Feasibility Study on District Heating and Cooling Business Using Urban Waste Heat

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Joon; Choi, Byoung Youn; Lee, Kyoung Ho; Lee, Jae Bong [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Yoo, Jae In; Yoon, Jae Ho; Oh, Myung Do; Park, Moon Su; Kang, Han Kee; Yoo, Kyeoung Hoon; Bak, Jong Heon; Kim, Sun Chang; Park, Heong Kee; Bae, Tae Sik [Korea Academy of Industrial Technology, Seoul (Korea, Republic of)

1996-12-31

Investigation of papers related to waste heat utilization using heat pump. Estimate of various kinds of urban waste heat in korea. Investigation and study on optimal control of district heating and cooling system. Prediction of energy saving and environmental benefits when the urban waste heat will be used as heat source and sink of heat pump for district heating and cooling. Estimation of economic feasibility on district heating and cooling project utilizing urban waste heat. (author). 51 refs., figs

Geothermal energy systems plan for Boise City

Energy Technology Data Exchange (ETDEWEB)

1979-01-01

This is a plan for development of a downtown Boise geothermal district space heating system incorporating legal, engineering, organizational, geological, and economic requirements. Topics covered include: resource characteristics, system design and feasibility, economic feasibility, legal overview, organizational alternatives, and conservation. Included in appendices are: property ownership patterns on the Boise Front, existing hot well data, legal briefs, environmental data, decision point communications, typical building heating system retrofit schematics, and background assumptions and data for cost summary. (MHR)

Direct utilization of geothermal energy for space and water heating at Marlin, Texas. Final report

Energy Technology Data Exchange (ETDEWEB)

Conover, M.F.; Green, T.F.; Keeney, R.C.; Ellis, P.F. II; Davis, R.J.; Wallace, R.C.; Blood, F.B.

1983-05-01

The Torbett-Hutchings-Smith Memorial Hospital geothermal heating project, which is one of nineteen direct-use geothermal projects funded principally by DOE, is documented. The five-year project encompassed a broad range of technical, institutional, and economic activities including: resource and environmental assessments; well drilling and completion; system design, construction, and monitoring; economic analyses; public awareness programs; materials testing; and environmental monitoring. Some of the project conclusions are that: (1) the 155/sup 0/F Central Texas geothermal resource can support additional geothermal development; (2) private-sector economic incentives currently exist, especially for profit-making organizations, to develop and use this geothermal resource; (3) potential uses for this geothermal resource include water and space heating, poultry dressing, natural cheese making, fruit and vegetable dehydrating, soft-drink bottling, synthetic-rubber manufacturing, and furniture manufacturing; (4) high maintenance costs arising from the geofluid's scaling and corrosion tendencies can be avoided through proper analysis and design; (5) a production system which uses a variable-frequency drive system to control production rate is an attractive means of conserving parasitic pumping power, controlling production rate to match heating demand, conserving the geothermal resource, and minimizing environmental impacts.

Solar district heating and cooling: A review

DEFF Research Database (Denmark)

Perez-Mora, Nicolas; Bava, Federico; Andersen, Martin

2018-01-01

and decentralized solar district heating as well as block heating. For the different technologies, the paper describes commonly adopted control strategies, system configurations, types of installation, and integration. Real‐world examples are also given to provide a more detailed insight into how solar thermal...... technology can be integrated with district heating. Solar thermal technology combined with thermally driven chillers to provide cooling for cooling networks is also included in this paper. In order for a technology to spread successfully, not only technical but also economic issues need to be tackled. Hence......Both district heating and solar collector systems have been known and implemented for many years. However, the combination of the two, with solar collectors supplying heat to the district heating network, is relatively new, and no comprehensive review of scientific publications on this topic could...

Surface-near geothermal energy. Ground coupled heat pumps and underground thermal energy storage; Oberflaechennahe Geothermie. Erdgekoppelte Waermepumpen und unterirdische thermische Energiespeicher

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

Within the eleventh International User Forum at 27th/28th September, 2011 in Regensburg (Federal Republic of Germany) the following lectures were held: (1) Ecologic evaluation of heat pumps - a question of approach (Roland Koenigsdorff); (2) An actual general comment to WHG, the preparations for the new VAUwS and possible consequences on the surface-near geothermal energy (Walker-Hertkorn); (3) Field-test experiences: Ground source heat pumps in small residential buildings (Jeannette Wapler); (4) GeoT*SOL basic - Program for the evaluation and simulation of heat pump systems (Bernhard Gatzka); (5) Monitoring and modelling of geothermal heat exchanger systems (Fabian Ochs); (6) Thermal response tests for the quality assurance of geothermal heat probes (Markus Proell); (7) Process of determining an untroubled soil temperature in comparison (Andreas Koehler); (8) Borehole resistance - Is the TRT measured value also the planning value? (Roland Koenigsdorff); (9) Consideration of the heat transport in geothermal probes (Martin Konrad); (10) Process of evaluation the sealing of geothermal probes with backfilling materials (Manfred Reuss); (11) Quality assessment of geothermal probes in real standard (Mathieu Riegger); (12) Comparison of flat collectors salt water and direct evaporation, design, impacs, consequences (Bernhard Wenzel); (13) Non-covered photovoltaic thermal collectors in heat pump systems (Erik Bertram); (14) Seasonal geothermal probe-heat storage - Heat supply concepts for objects with overbalancing heating level of more than 100 kW (Volker Liebel); (15) Application of geothermal probe fields as a cold storage (Rolf Wagner); (16) Geothermal energy and waste water warmth: State of the art and new technologies for a combined utilization (Wolfram Stodtmeister); (17) Integration of a heat pump into a solar supported local heat supply in Neckarsulm (Janet Nussbicker-Lux); (18) Regenerative heating with photovoltaics and geothermal energy (Christoph Rosinski

An analysis of geothermal heating and engineering cost in Tianjin, China

International Nuclear Information System (INIS)

Wang, W.

1990-01-01

Tianjin is a region with fairly rich low-temperature geothermal resources. Its climate and soaring price of raw coals have made geo heating in Tianjin develop rapidly over the past 5 years. The types of heating systems fall into 3 categories and the primary factors for using temperature drop are 5. According to economical analysis, the optimal discharge temperature in the space heating is about 43 degrees C and the minimum discharge temperature 35 degrees C approximately. This paper reports that an analysis of a typical engineering costs involved shows that the advantages of geo space heating are not notable when compared with burning coals. However, to reduce air pollution, the state and general public are ready to support the development of such geothermal wells as deep as 3,000 m for space heating irrespective of their sole engineering costs

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.

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.

Is Swedish district heating operating on an integrated market? – Differences in pricing, price convergence, and marketing strategy between public and private district heating companies

International Nuclear Information System (INIS)

Åberg, M.; Fälting, L.; Forssell, A.

2016-01-01

The deregulation of the Swedish electricity market in 1996 made it possible to operate municipal district heating commercially. Until that time district heating had been organized mainly as municipal utilities. After 1996 district heating is instead expected to function on a market. In competitive and integrated markets, prices are expected to be equal, or converging. To find out if district heating operates on an integrated market the differences in price levels, price convergence, price strategy, and business goals, among municipal, private and state owned district heating companies are investigated. Price statistics was used along with results from a questionnaire that was answered by representatives for 109 Swedish district heating companies. The results show that prices among district heating systems do not converge significantly and that variations in prices among municipal systems are larger than among private and state owned systems. Furthermore, despite the fact that district heating is supposed to be commercial, a vast majority of district heating companies apply cost-based pricing and not market pricing. The municipal companies give priority to political goals before financial goals. The conclusion is that a Swedish integrated market for heat has not yet evolved, and some district heating price-controlling mechanism is necessary. - Highlights: • Price statistics and owner type data were used along with results from a questionnaire. • Results show that prices among district heating systems do not converge. • Municipal district heating companies still apply cost-based pricing to a large extent. • District heating companies are not operating on an integrated market for heat. • Some price-controlling mechanism for district heating is necessary.

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.)

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.

Residential heating costs: A comparison of geothermal solar and conventional resources

Science.gov (United States)

Bloomster, C. H.; Garrett-Price, B. A.; Fassbender, L. L.

1980-08-01

The costs of residential heating throughout the United States using conventional, solar, and geothermal energy were determined under current and projected conditions. These costs are very sensitive to location, being dependent on the local prices of conventional energy supplies, local solar insolation, climate, and the proximity and temperature of potential geothermal resources. The sharp price increases in imported fuels during 1979 and the planned decontrol of domestic oil and natural gas prices have set the stage for geothermal and solar market penetration in the 1980's.

Design of a novel geothermal heating and cooling system: Energy and economic analysis

International Nuclear Information System (INIS)

Angrisani, G.; Diglio, G.; Sasso, M.; Calise, F.; Dentice d’Accadia, M.

2016-01-01

Highlights: • A desiccant-based air handling unit is coupled with a geothermal source. • A TRNSYS model is developed to simulate both winter and summer period. • Sensitivity analysis is carried out in order to evaluate the effects of the design parameters. • Pay back period about 1.2 years and Primary Energy Savings higher than 90% were founded. • Economic and energetic performance increase with to the use of Domestic Hot Water. - Abstract: A dynamic simulation study in TRNSYS environment has been carried out to evaluate energy and economic performance of a novel heating and cooling system based on the coupling between a low or medium-enthalpy geothermal source and an Air Handling Unit, including a Desiccant Wheel. During summer season, a Downhole Heat Exchanger supplies heat to regenerate the desiccant material, while a certain amount of geothermal fluid is continuously extracted by the well in order to maintain high operating temperatures. Simultaneously, the extracted geothermal fluid drives an absorption chiller, producing chilled water to the cooling coil of the Air Handling Unit. Conversely, during the winter season, geothermal energy is used to cover a certain amount of the space heating demand. In both summer and winter operation modes, a geothermal energy is also used to supply Domestic Hot Water. A case study was analyzed, in which an existing low-enthalpy geothermal well (96 °C), located in Ischia (an island close to Naples, Southern Italy), is used to drive the geothermal system. Results showed that the performance of the proposed system is significantly affected by the utilization factor of Domestic Hot Water. In fact, considering a range of variation of such parameter between 5% and 100%, Primary Energy Saving increase from 77% to 95% and Pay-Back Period decreases from 14 years to 1.2 years, respectively. The simulations proved the technical and economic viability of the proposed system. In fact, a comparison with similar systems available

Modelling of Thermal Behavior of Borehole Heat Exchangers of Geothermal Heat Pump Heating Systems

Directory of Open Access Journals (Sweden)

Gornov V.F.

2016-01-01

Full Text Available This article reports results of comparing the accuracy of the software package “INSOLAR.GSHP.12”, modeling non-steady thermal behavior of geothermal heat pump heating systems (GHCS and of the similar model “conventional” using finite difference methods for solving spatial non-steady problems of heat conductivity. The software package is based on the method of formulating mathematical models of thermal behavior of ground low-grade heat collection systems developed by INSOLAR group of companies. Equations of mathematical model of spatial non-steady thermal behavior of ground mass of low-grade heat collection system obtained by the developed method have been solved analytically that significantly reduced computing time spent by the software complex “INSOLAR.GSHP.12” for calculations. The method allows to turn aside difficulties associated with information uncertainty of mathematical models of the ground thermal behavior and approximation of external factors affecting the ground. Use of experimentally obtained information about the ground natural thermal behavior in the software package allows to partially take into account the whole complex of factors (such as availability of groundwater, their velocity and thermal behavior, structure and arrangement of ground layers, the Earth’s thermal background, precipitation, phase transformations of moisture in the pore space, and more, significantly influencing the formation of thermal behavior of the ground mass of a low-grade geothermal heat collection system. Numerical experiments presented in the article confirmed the high convergence of the results obtained through the software package “INSOLAR.GSHP.12” with solutions obtained by conventional finite-difference methods.

Co-sponsored second quarter progress review conference on district heating

Energy Technology Data Exchange (ETDEWEB)

None

1980-01-01

A summary of the progress review conference on district heating and cooling systems is presented. The agenda and lists of speakers and attendees are presented. A history of district heating and some present needs and future policies are given and an excerpt from the National District Heating Program Strategy (DOE, March 1980) is included. Following the presentation, District Heating and Cooling Systems Program, by Alan M. Rubin, a fact sheet on DOE's Integrated Community Energy Systems Program and information from an oral presentation, District Heating and Cooling Systems for Communities Through Power Plant Retrofit Distribution Network, are given. The Second Quarterly Oral Report to the US DOE on the District Heating and Cooling Project in Detroit; the executive summary of the Piqua, Ohio District Heating and Cooling Demonstration Project; the Second Quarterly Report of the Moorehead, Minnesota District Heating Project; and the report from the Moorehead, Minnesota mayor on the Hot Water District Heating Project are presented.

Integration of space heating and hot water supply in low temperature district heating

DEFF Research Database (Denmark)

Elmegaard, Brian; Ommen, Torben Schmidt; Markussen, Michael

2016-01-01

District heating may supply many consumers efficiently, but the heat loss from the pipes to the ground is a challenge. The heat loss may be lowered by decreasing the network temperatures for which reason low temperature networks are proposed for future district heating. The heating demand...... of the consumers involves both domestic hot water and space heating. Space heating may be provided at low temperature in low energy buildings. Domestic hot water, however, needs sufficient temperatures to avoid growth of legionella. If the network temperature is below the demand temperature, supplementary heating...... is required by the consumer. We study conventional district heating at different temperatures and compare the energy and exergetic efficiency and annual heating cost to solutions that utilize electricity for supplementary heating of domestic hot water in low temperature district heating. This includes direct...

Numerical Simulation of Nanofluid Suspensions in a Geothermal Heat Exchanger

Directory of Open Access Journals (Sweden)

Xiao-Hui Sun

2018-04-01

Full Text Available It has been shown that using nanofluids as heat carrier fluids enhances the conductive and convective heat transfer of geothermal heat exchangers. In this paper, we study the stability of nanofluids in a geothermal exchanger by numerically simulating nanoparticle sedimentation during a shut-down process. The nanofluid suspension is modeled as a non-linear complex fluid; the nanoparticle migration is modeled by a particle flux model, which includes the effects of Brownian motion, gravity, turbulent eddy diffusivity, etc. The numerical results indicate that when the fluid is static, the nanoparticle accumulation appears to be near the bottom borehole after many hours of sedimentation. The accumulated particles can be removed by the fluid flow at a relatively high velocity. These observations indicate good suspension stability of the nanofluids, ensuring the operational reliability of the heat exchanger. The numerical results also indicate that a pulsed flow and optimized geometry of the bottom borehole can potentially improve the suspension stability of the nanofluids further.

Upscaling a district heating system based on biogas cogeneration and heat pumps

NARCIS (Netherlands)

van Leeuwen, Richard Pieter; Fink, J.; Smit, Gerardus Johannes Maria; de Wit, Jan B.

2015-01-01

The energy supply of the Meppel district Nieuwveense landen is based on biogas cogeneration, district heating, and ground source heat pumps. A centrally located combined heat and power engine (CHP) converts biogas from the municipal wastewater treatment facility into electricity for heat pumps and

Make the heat hotter. - marketing district heating to households in detached houses

Energy Technology Data Exchange (ETDEWEB)

Sernhed, Kerstin; Pyrko, Jurek

2008-09-15

For district heating (DH) companies, to expand in low heat density areas such as detached houses, it is essential to obtain a high rate of connections to the district-heating network in order to enhance the cost effectiveness. Marketing district heating to house owners is, however, a fairly different matter from selling it to customers in industrial, commercial, and multi-family buildings. Suitable market strategies need to be developed and the need for information about potential customers' preferences and attitudes are of great importance since the house-owners often constitute a heterogeneous group where different households have different requirements. This paper investigates a case of one Swedish district heating company's marketing activities and expansion strategies in a single family house area where the customers were offered conversion of their direct resistive electric heating (DEH) into district heating (DH). 88 out of 111 houses were converted in 2002. Four years later, interviews were carried out with 23 of the households in the area, both with those who had accept-ed the district heating offer and those who had not. The study shows that apart from the economic aspects, thermal comfort, aesthetics and practicalities also affected the buying decision. Since the different economic aspects of the offer were complex, it was very difficult for the households to make a strictly rational economical decision. Statistical analysis confirmed that variables such as age, type of household and energy use level could, to some extent, be related to the decision to convert from electric heating to district heating. Timing, low prices and the total solutions presented to the households were crucial factors in the success of the marketing strategy.

New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

International Nuclear Information System (INIS)

Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

2012-01-01

A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

Integration of Space Heating and Hot Water Supply in Low Temperature District Heating

DEFF Research Database (Denmark)

Elmegaard, Brian; Ommen, Torben Schmidt; Markussen, Michael

2014-01-01

pipes, where the water is at the highest temperature. The heat loss may be lowered by decreasing the temperatures in the network for which reason low temperature networks are proposed as a low loss solution for future district heating. However, the heating demand of the consumers involve both domestic......District heating makes it possible to provide heat for many consumers in an efficient manner. In particular, district heating based on combined heat and power production is highly efficient. One disadvantage of district heating is that there is a significant heat loss from the pipes...... to the surrounding ground. In larger networks involving both transmission and distribution systems, the heat loss is most significant from the distribution network. An estimate is that about 80-90 % of the heat loss occurs in the distribution system. In addition, the heat loss is naturally highest from the forward...

Performance Analysis of a Hybrid District Heating System

DEFF Research Database (Denmark)

Mikulandric, Robert; Krajačić, Goran; Duic, Neven

2015-01-01

Hybridisation of district heating systems can contribute to more efficient heat generation through cogeneration power plants or through the share increase of renewable energy sources in total energy consumption while reducing negative aspects of particular energy source utilisation. In this work......, the performance of a hybrid district energy system for a small town in Croatia has been analysed. Mathematical model for process analysis and optimisation algorithm for optimal system configuration has been developed and described. The main goal of the system optimisation is to reduce heat production costs....... Several energy sources for heat production have been considered in 8 different simulation cases. Simulation results show that the heat production costs could be reduced with introduction of different energy systems into an existing district heating system. Renewable energy based district heating systems...

Performance analysis of hybrid district heating system

DEFF Research Database (Denmark)

Mikulandric, Robert; Krajačić, Goran; Khavin, Gennadii

2013-01-01

District heating system could contribute to more efficient heat generation through cogeneration power plants or waste heat utilization facilities and to increase of renewable energy sources share in total energy consumption. In the most developed EU countries, renewable energy sources have been...... as problems related to transportation, storage and environmental impacts of biomass and waste utilisation. Implementation of heat storages in district heating systems could contribute to integration of intermittent energy sources. Hybridisation of heat production facility combines two or more different energy...... more extensively used in district heating systems either separately or as a supplement to traditional fossil fuels in order to achieve national energy policy objectives. However, they are still facing problems such as high intermittences, high energy production costs and low load factors as well...

Quantification of exploitable shallow geothermal energy by using Borehole Heat Exchanger coupled Ground Source Heat Pump systems

International Nuclear Information System (INIS)

Hein, Philipp; Zhu, Ke; Bucher, Anke; Kolditz, Olaf; Pang, Zhonghe; Shao, Haibing

2016-01-01

Highlights: • The amount of technically exploitable shallow geothermal energy was quantified. • Therefore, a comprehensive numerical borehole heat exchanger model was employed. • The concept of equivalent temperature drop is introduced. • For one BHE, an equivalent temperature drop of 1.8–2.8 °C over 30 years is realistic • The average extractable energy amount evaluates to be 3.5–5.4 kW h m"−"2 a"−"1. - Abstract: In previous studies, the amount of exploitable shallow geothermal energy was estimated by assuming a uniform temperature drop of 2–6 °C in the aquifer. In this work, a more comprehensive numerical model has been employed to evaluate the available amount of shallow geothermal energy by using Borehole Heat Exchanger coupled Ground Source Heat Pump systems. Numerical experiments have been performed by simulating the long-term evolution of the subsurface temperature field, which is subject to the operation of borehole heat exchangers and varying parameters like subsurface thermal conductivity and groundwater flow velocity. The concept of equivalent temperature drop is proposed as an auxiliary quantity for the subsurface. With the help of this parameter, a procedure has been established to quantify the amount of shallow geothermal potential. Following this approach, a realistic equivalent temperature reduction is found to be from −1.8 to −4.4 °C in the subsurface over a period of 30 years. This can be translated to an annual extractable geothermal energy value in a unit surface area, and it ranges from 3.5 to 8.6 kW h m"−"2 a"−"1. The exact value is site specific and heavily depends on the soil thermal conductivity, groundwater velocity, and borehole arrangement.

District heating in Italy: Extent of use

International Nuclear Information System (INIS)

Sacchi, E.

1992-01-01

The Author surveys the trend that has been established over the last two decades in the use of district heating in Italy. Comparison with the European situation reveals that Italy is lagging behind. The reason for this the Author states is the Italian public's aversion to unknown risks involved in the utilization of innovative technologies associated with cogeneration/district heating (current preference is given to autonomous methane fuelled building space heating systems), and the current opinion of some misinformed public administrations that cogeneration/district heating plants are too costly. Citing the successful campaign by the natural gas industry to promote the public acceptance of methane as a safe, readily available and competitively priced energy source, he suggests that similar efforts be made to have the public also accept cogeneration (with methane fired gas turbines)/district heating as being safe and environmentally, as well as, economically beneficial

Base-line data analysis of a developing geothermal system, Boise, Idaho

Energy Technology Data Exchange (ETDEWEB)

Waag, C.J.; Wood, S.H.

1985-09-01

The report covers a geothermal system and calculated aquifer transmissivities in the Boise Warm Springs Water District portion of the geothermal system range from 3500-25,000 gals/day/ft. Withdrawals during the 1984-1985 heating season stabilized drawdown at the pumpbowls, and water levels approached stability in observation wells as distant as 1675 ft (507.6m). In the near steady-state condition, recharge, and water from storage beyond the observation wells provided a maximum Q of 840 gpm.

Environmental issues and competitiveness of district heating systems

International Nuclear Information System (INIS)

Kypreos, S.

1991-01-01

The advantages of district heating systems are evaluated in competition to individual heating for the Swiss markets. The preservation of the environmental quality on the national (clean air concept) and global scale (Toronto recommendation) is formulated as constraint of the energy system. The implications of these constraints for the economic competition of district heating is evaluated. The study estimates the evolution of energy demand in the heating markets and shortly describes the technical possibilities in satisfying demand by a set of conventional heating systems, systems using renewable energy sources, energy conservation measures and district heating systems based on conventional or nuclear energy sources. The main conclusion is that small capacity nuclear district heating systems, if acceptable, could enhance the flexibility of the Swiss energy system in respect to CO 2 control. (author) 3 figs., 4 tabs., 9 refs

The situation of district heating, district cooling and energy supply in Hungary

International Nuclear Information System (INIS)

Sigmond, Gy.

2009-01-01

District heating represents with 650.000 heated dwellings approximately 15% of the Hungarian residential heating market. Since 1990 there is stagnation at the number of connected dwellings because erection of large settlements with prefab buildings has been stopped, and latter ones represent more than 75% of the dwelling heating market. During the same period, residential heat demand shrunk by 33%, because metering of hot water consumption resulted in changing consumer habits, and because of slowly but step by step refurbishment of buildings and heating systems. In Hungary district heating is present in all large and most of the medium size cities, in 92 cities together. Out of them, there is also a single village with a local district heating system, which heats more than 60% of cottages. The capacity os systems is spreading to a large extent. Approximately 36-36% of all heated dwellings are in Budapest and in 10 large cities in the country, while 148 of the total 202 systems have less than 10 MW capacities. In the fuel structure of district heating it is characteristic the overwhelming role of natural gas consumption, which has exceeded 80% already. Only a few numbers of heating power plants are fuelled by crown coal. The use of renewables is growing continuous, but, together with waste and waste energy, it amounts merely 8% of the total fuel use. Oil consumption is negligible. Currently the most promising DH-market is the service sector (public buildings and commercial consumers). DH-companies can sell their surplus supply capacities on the competitive market. Residential market can be preserved only with better legal conditions and with improving of demand side management. The industrial heat market can be gained when the erection of new power plants will be harmonized with industrial development in the frame of territorial planning. District cooling is just at the beginning in Hungary. Many new commercial and office buildings are erected with air conditioning

Local business models for district heat production; Kaukolaemmoen paikalliset liiketoimintamallit

Energy Technology Data Exchange (ETDEWEB)

Hakala, L.; Pesola, A.; Vanhanen, J.

2012-12-15

Local district heating business, outside large urban centers, is a profitable business in Finland, which can be practiced with several different business models. In addition to the traditional, local district heating business, local district heat production can be also based on franchising business model, on integrated service model or on different types of cooperation models, either between a local district heat producer and industrial site providing surplus heat or between a local district heat producer and a larger district heating company. Locally available wood energy is currently utilized effectively in the traditional district heating business model, in which a local entrepreneur produces heat to consumers in the local area. The franchising model is a more advanced version of the traditional district heating entrepreneurship. In this model, franchisor funds part of the investments, as well as offers centralized maintenance and fuel supply, for example. In the integrated service model, the local district heat producer offers also energy efficiency services and other value-added services, which are based on either the local district heat suppliers or his partner's expertise. In the cooperation model with industrial site, the local district heating business is based on the utilization of the surplus heat from the industrial site. In some cases, profitable operating model approach may be a district heating company outsourcing operations of one or more heating plants to a local entrepreneur. It can be concluded that all business models for district heat production (traditional district heat business model, franchising, integrated service model, cooperative model) discussed in this report can be profitable in Finnish conditions, as well for the local heat producer as for the municipality - and, above all, they produce cost-competitive heat for the end-user. All the models were seen as viable and interesting and having possibilities for expansion Finland

Performance assessment of a novel hybrid district energy system

International Nuclear Information System (INIS)

Coskun, C.; Oktay, Z.; Dincer, I.

2012-01-01

In this paper, a new hybrid system for improving the efficiency of geothermal district heating systems (GDHSs) is proposed. This hybrid system consists of biogas based electricity production and a water-to-water geothermal heat pump unit (GHPU), which uses the waste heat for both heating and domestic hot water purposes. Electricity generated by the biogas plant (BP) is utilized to drive the GDHS's pumps, BP systems and the heat pump units. Both the biogas reactor heating unit and the heat pump unit utilize the waste heat from the GDHS and use the system as a heat source. The feasibility of utilizing a hybrid system in order to increase the overall system (GDHS + BP + GHPU) efficiency is then investigated for possible efficiency improvements. The Edremit GDHS in Turkey, which is selected for investigation in this case study, reinjects 16.8 MW of thermal power into the river at a low temperature; namely at 40 °C. Such a temperature is ideal for mesophilic bacterial growth in the digestion process during biogas production. 1.45 MW of biogas based electricity production potential is obtainable from the waste heat output of the Edremit GDHS. The average overall system efficiencies through the utilization of this kind of hybridized system approach are increased by 7.5% energetically and 13% for exergetically. - Highlights: ► A new hybrid system is proposed for improving the efficiency of geothermal district heating systems (GDHSs). ► The average overall system efficiencies are increased by 7.5% for energy and 13% for exergy, respectively. ► Various energetic and exergetic parameters are studied.

Waste heat of HTR power stations for district heating

International Nuclear Information System (INIS)

Bonnenberg, H.; Schlenker, H.V.

1975-01-01

The market situation, the applied techniques, and the transport, for district heating in combination with HTR plants are considered. Analysis of the heat market indicates a high demand for heat at temperatures between 100 and 150 0 C in household and industry. This market for district heating can be supplied by heat generated in HTR plants using two methods: (1) the combined heat and power generation in steam cycle plants by extracting steam from the turbine, and (2) the use of waste heat of a closed gas turbine cycle. The heat generation costs of (2) are negligible. The cost for transportation of heat over the average distance between existing plant sites and consumer regions (25 km) are between 10 and 20% of the total heat price, considering the high heat output of nuclear power stations. Comparing the price of heat gained by use of waste heat in HTR plants with that of conventional methods, considerable advantages are indicated for the combined heat and power generation in HTR plants. (author)

Exploration for geothermal resources in the Capital District of New York. Volume 1. Final report

Energy Technology Data Exchange (ETDEWEB)

1981-11-01

Water chemistry, gas analyses, and geophysical methods including gravity and magnetic surveys, microseismic monitoring, and temperature gradient measurements were used in the Capital District area to evaluate the potential for a hydrothermal geothermal system. Water and gas chemistries provided indirect indicators, and temperature gradients provided direct indications of a geothermal system. Gravity results were supportive of gradient and chemistry data, but seismic and magnetic work have thus far provided little information on the potential system. Gradients throughout the area ranged from an average background value of about 10/sup 0/C/km to a high of roughly 44/sup 0/C/km. The highest gradient values, the most unusual water chemistries and largest carbon dioxide exhalations occur along the Saratoga and McGregor faults between Saratoga Springs and Schenectady, and indicate a good potential for a usable hydrothermal geothermal system at depth.

A comparison of economic evaluation models as applied to geothermal energy technology

Science.gov (United States)

Ziman, G. M.; Rosenberg, L. S.

1983-01-01

Several cost estimation and financial cash flow models have been applied to a series of geothermal case studies. In order to draw conclusions about relative performance and applicability of these models to geothermal projects, the consistency of results was assessed. The model outputs of principal interest in this study were net present value, internal rate of return, or levelized breakeven price. The models used were VENVAL, a venture analysis model; the Geothermal Probabilistic Cost Model (GPC Model); the Alternative Power Systems Economic Analysis Model (APSEAM); the Geothermal Loan Guarantee Cash Flow Model (GCFM); and the GEOCOST and GEOCITY geothermal models. The case studies to which the models were applied include a geothermal reservoir at Heber, CA; a geothermal eletric power plant to be located at the Heber site; an alcohol fuels production facility to be built at Raft River, ID; and a direct-use, district heating system in Susanville, CA.

Geothermal Heat Pumps Score High Marks in Schools.

Science.gov (United States)

National Renewable Energy Lab (DOE).

Geothermal heat pumps (GHPs) are showing their value in providing lower operating and maintenance costs, energy efficiency, and superior classroom comfort. This document describes what GHPs are and the benefits a school can garner after installing a GHP system. Three case studies are provided that illustrate these benefits. Finally, the Department…

Study of an innovative ejector heat pump-boosted district heating system

International Nuclear Information System (INIS)

Zhang, Bo; Wang, Yuanchao; Kang, Lisha; Lv, Jinsheng

2013-01-01

An Ejector heat pump-boosted District Heating (EDH) system is proposed to improve the heating capacity of existing district heating systems with Combined Heat and Power (CHP). In the EDH, two ejector heat pumps are installed: a primary heat pump (HP 1 ) at the heating station and a secondary heat pump (HP 2 ) at the heating substation. With the EDH, the low-grade waste heat from circulating cooling water in the CHP is recycled and the temperature difference between the water supply and the return of the primary heating network is increased. A thermodynamic model was provided. An experimental study was carried out for both HP 1 and HP 2 to verify the predicting performance. The results show that the COP of HP 1 can reach 1.5–1.9, and the return water temperature of the primary heating network could be decreased to 35 °C with HP 2 . A typical case study for the EDH was analyzed. -- Highlights: • An ejector heat pump-boosted district heating (EDH) is proposed. • The 1st ejector heat pump in EDH recycles heat from cooling water of the CHP. • The 2nd ejector heat pump in EDH boosts the thermal energy utilization of the primary heating network. • Modeling and experimental studies are presented

Pahoa geothermal industrial park. Engineering and economic analysis for direct applications of geothermal energy in an industrial park at Pahoa, Hawaii

Energy Technology Data Exchange (ETDEWEB)

Moreau, J.W.

1980-12-01

This engineering and economic study evaluated the potential for developing a geothermal industrial park in the Puna District near Pahoa on the Island of Hawaii. Direct heat industrial applications were analyzed from a marketing, engineering, economic, environmental, and sociological standpoint to determine the most viable industries for the park. An extensive literature search produced 31 existing processes currently using geothermal heat. An additional list was compiled indicating industrial processes that require heat that could be provided by geothermal energy. From this information, 17 possible processes were selected for consideration. Careful scrutiny and analysis of these 17 processes revealed three that justified detailed economic workups. The three processes chosen for detailed analysis were: an ethanol plant using bagasse and wood as feedstock; a cattle feed mill using sugar cane leaf trash as feedstock; and a papaya processing facility providing both fresh and processed fruit. In addition, a research facility to assess and develop other processes was treated as a concept. Consideration was given to the impediments to development, the engineering process requirements and the governmental support for each process. The study describes the geothermal well site chosen, the pipeline to transmit the hydrothermal fluid, and the infrastructure required for the industrial park. A conceptual development plan for the ethanol plant, the feedmill and the papaya processing facility was prepared. The study concluded that a direct heat industrial park in Pahoa, Hawaii, involves considerable risks.

A geothermal recycling system for cooling and heating in deep mines

International Nuclear Information System (INIS)

Guo, Pingye; He, Manchao; Zheng, Liange; Zhang, Na

2017-01-01

Highlights: • A geothermal recycling system for cooling and heating was presented in coal mines. • The COP of this cooling subsystem is 30% higher than that of others. • The COP is 20% higher with the parallel running of cooling and heating systems. - Abstract: In the operation of deep coal mines, cooling systems must be built (in most cases) because of the high-temperature working environment within such mines. Once the coal is mined, it is often used to supply heat for buildings and domestic hot water. In either instance, the energy consumed can create environmental pollution. As a potential solution to this problem, we present a geothermal recycling system for mines (GRSM) for parallel mine cooling and surface heating. The performance of this system is investigated based on the observed data. Compared with traditional cooling systems, the most obvious feature of this system is the removal of a cooling tower, which contributes to a 30% increase in performance. Moreover, the parallel running of cooling and heating systems can effectively recover waste heat, improving energy efficiency by 20%.

Application of Predictive Control in District Heating Systems

DEFF Research Database (Denmark)

Palsson, Olafur Petur; Madsen, Henrik; Søgaard, Henning Tangen

1993-01-01

In district heating systems, and in particular if the heat production cakes place at a combined heat and power (CHP) plant, a reasonable control strategy is to keep the supply temperature from the district heating plant as low as possible. However, the control is subject to some restrictions, for...

State of the art of heating greenhouses with geothermal energy in Yugoslavia

International Nuclear Information System (INIS)

Milivojevic, M.; Martinovic, M.; Vidovic, S.

2000-01-01

The surface of Yugoslavia is relatively small (about 80.000 km 2 ) but its geological and tectonic structure are very complex. Because of that, geothermal characteristics of its territory are interesting. On two thirds of Yugoslav territory values of the heat flow density are greater than average values for the continental part of Europe and on the half of the territory they are around 100 MW/m 2 (Milivojevic, 1989). Consequently, on the territory of Yugoslavia there are more than 60 hydro-geo-thermal low-temperature connective systems (T o C) as well as enormous hydrothermal conductive system in the Yugoslav part of Pannonic basin. In the last three years a lot of effort is put into continuing geothermal researches but the progress is very small. Thus, since the UN embargo was rescinded in 1995 not a single well has been bored yet. The reasons for this are: economic crisis, the beginning of the transition process, energetic focus on the import of oil and gas as well as the fact that people are not conscious about the necessity of increasing energy efficiency and energy rationalisation. Nowadays, geothermal energy is used for the heating of greenhouses and plastic houses here in Yugoslavia. Although that surfaces of geothermal greenhouses and plastic buildings are very small, just about 8 ha on three locations, their owners want to enlarge them since economic indicators show that the production of flowers and vegetables in geothermal greenhouses is better than in those heated on gas or liquid fuel. However, the lack of money for building new and modem complexes of greenhouses as well as for the revitalisation of existing ones prevents the development and enlarging of these buildings. Because of the fact that geothermal resources can be immediately used if the financial problem could be solved, the surfaces of geothermal greenhouses and plastic buildings in Yugoslavia could be several hectares larger. (Authors)

Multi-purpose utilization and development of geothermal water: European overseas investigation

Energy Technology Data Exchange (ETDEWEB)

Ochiai, T [Natl. Research Institute of Agricultural Engineering, Japan

1978-01-01

In order to investigate the agricultural utilization of geothermal waters, a fact-finding team visited France, Italy, Iceland, and Turkey. In France, it was seen that the development and utilization of geothermal waters is in accord with Japanese practices. The production and reinjection wells are drilled to a depth of 1800 m. They are spaced about 10 m apart at the surface and about 800 m apart at the bottom. This is accomplished by drilling at an angle. The hot water is produced at a rate of about 90 t/h. It is passed through a heat exchanger where it warms surface water to about 70/sup 0/C. The warmed water is then supplied for purposes of district heating, greenhouse culture, and fish farming. The used hot water is then returned to the producing stratum via the reinjection well. Iceland began the production of hot geothermal water in 1925, and, at present, 99% of the city of Reykjavik is heated geothermally. The deepest production wells at Reykjavik reach 2000 m. The water produced has a temperature of 90-103/sup 0/C, and is also used for agricultural purposes.

Nuclear power for district heating

International Nuclear Information System (INIS)

Lyon, R.B.; Sochaski, R.O.

1975-09-01

Current district heating trends are towards an increasing use of electricity. This report concerns the evaluation of an alternative means of energy supply - the direct use of thermal energy from CANDU nuclear stations. The energy would be transmitted via a hot fluid in a pipeline over distances of up to 40 km. Advantages of this approach include a high utilization of primary energy, with a consequent reduction in installed capacity, and load flattening due to inherent energy storage capacity and transport delays. Disadvantages include the low load factors for district heating, the high cost of the distribution systems and the necessity for large-scale operation for economic viability. This requirement for large-scale operation from the beginning could cause difficulty in the implementation of the first system. Various approaches have been analysed and costed for a specific application - the supply of energy to a district heating load centre in Toronto from the location of the Pickering reactor station about 40 km away. (author)

All around ecological. Administrative building of the district office Goeppingen; Rundum oekologisch. Verwaltungsgebaeude des Landratsamts Goeppingen

Energy Technology Data Exchange (ETDEWEB)

Anon.

2011-07-15

This district office in Goeppingen (Federal Republic of Germany) just had ten months in order to build a completely new administrative building. For the employees of the district's waste company, a house was needed with a gross floor area of 2,020 m{sup 2}. Despite the tight time frame, one correlated to an environmentally friendly and energy-saving concept: The building should consume energy as little as possible in future. The new building was constructed extremely rapidly and is now regarded as a flagship project: it is heated using a geothermal heat pump and seven geothermal probes. A sophisticated system provides for storage and recycling of excess energy.

Energy and exergy analysis of low temperature district heating network

International Nuclear Information System (INIS)

Li, Hongwei; Svendsen, Svend

2012-01-01

Low temperature district heating with reduced network supply and return temperature provides better match of the low quality building heating demand and the low quality heating supply from waste heat or renewable energy. In this paper, a hypothetical low temperature district heating network is designed to supply heating for 30 low energy detached residential houses. The network operational supply/return temperature is set as 55 °C/25 °C, which is in line with a pilot project carried out in Denmark. Two types of in-house substations are analyzed to supply the consumer domestic hot water demand. The space heating demand is supplied through floor heating in the bathroom and low temperature radiators in the rest of rooms. The network thermal and hydraulic conditions are simulated under steady state. A district heating network design and simulation code is developed to incorporate the network optimization procedure and the network simultaneous factor. Through the simulation, the overall system energy and exergy efficiencies are calculated and the exergy losses for the major district heating system components are identified. Based on the results, suggestions are given to further reduce the system energy/exergy losses and increase the quality match between the consumer heating demand and the district heating supply. -- Highlights: ► Exergy and energy analysis for low and medium temperature district heating systems. ► Different district heating network dimensioning methods are analyzed. ► Major exergy losses are identified in the district heating network and the in-house substations. ► Advantages to apply low temperature district heating are highlighted through exergy analysis. ► The influence of thermal by-pass on system exergy/energy performance is analyzed.

State and development prospects of district heating in the FRG

International Nuclear Information System (INIS)

Buch, A.

1975-12-01

The study outlines the state of district heating, investigates the preconditions of its increased application and determines the thus obtainable saving in energy consumption. The heat consumption in homes, the energy use and the types of heating for room heating and hot water supply, the covering of the demand for district heating, design of a district heating supply, the regional planning and the production costs of district heating are individually considered. The results are shown clearly in tables, maps and and graphs. (HR/LH) [de

Economic and environmental efficiency of district heating plants

DEFF Research Database (Denmark)

Agrell, Per J.; Bogetoft, Peter

2005-01-01

heat, have arbitrary valuation.This study concerns the most developed European district heating and cogeneration system, the Danish.By assessing environmental and economic ef¿ciency, the impact of governmental, market and managerial imperfections are estimated.The principal methodological base......District heating, the conversion of primary energy into distributed thermal energy and possible electric energy, is a challenge to regulate.In addition to the ever present asymmetric information in any suf¿ciently complex activity, some of the inputs for district heating, such as excess process...

Thermoeconomic Analysis of Hybrid Power Plant Concepts for Geothermal Combined Heat and Power Generation

Directory of Open Access Journals (Sweden)

Florian Heberle

2014-07-01

Full Text Available We present a thermo-economic analysis for a low-temperature Organic Rankine Cycle (ORC in a combined heat and power generation (CHP case. For the hybrid power plant, thermal energy input is provided by a geothermal resource coupled with the exhaust gases of a biogas engine. A comparison to alternative geothermal CHP concepts is performed by considering variable parameters like ORC working fluid, supply temperature of the heating network or geothermal water temperature. Second law efficiency as well as economic parameters show that hybrid power plants are more efficient compared to conventional CHP concepts or separate use of the energy sources.

Economic viability of geothermal energy usage in comparison to renewable and conventional energy systems; Wirtschaftlichkeit geothermischer Energiegewinnung im Rahmen regenerativer und konventioneller Energiesysteme

Energy Technology Data Exchange (ETDEWEB)

Schaumann, G

2002-07-01

This comprehensive lecture given by Prof. Dr. Gunter Schaumann in Bad Duerkheim, Germany, discusses the use of geothermal energy in relationship to other forms of renewable energy sources and conventional energy technologies used to provide heat, power and motive force. The characteristics of geothermal energy from various sources and examples of its possible use are discussed. In particular, the paper deals with deep geothermal energy, which can provide heating energy for district heating schemes, if necessary with the help of heat pumps. The prospects of such a use of geothermal energy in the next 50 years in various suitable regions in Germany is discussed and the associated prerequisites are listed. The present situation concerning the use of geothermal energy in Germany is examined. An example of a geothermal heating power station that also features a gas-fired combined heat and power installation, a heat pump and a peak-load boiler is given. Also, the generation of electrical power using the Organic Rankine Cycle is discussed. The factors influencing the economic viability of geothermal power stations are discussed in detail and the resulting energy prices are compared with conventional plants. The paper gives details of the calculation of investment and energy costs for heat and power generation and presents figures based on exemplary installations.

New possibilities and perspectives of building hotwater line from geothermal wells heat exchanger to TEKO Košice

Directory of Open Access Journals (Sweden)

Marína Sidorová

2006-04-01

Full Text Available Thank to favourable geological conditions, Slovakia is a country abundant in the occurrence of low-enthalpy sources. The government of the state sponsors new renewable of the sources ecological energy,including the geothermal energy. Geothermal water is utilized for recreation (swimming pools, spas, agriculture (heating of greenhouses, fishing and heating of houses. The effectivity of utilisation is about 30 % due to its seasonal use. That is why the annual house-heating and the hot water supply from geothermal sources are supported. Recently, the company Slovgeoterm has initiated heating of greenhouses in Podhajska and hospital and 1231 flats in the town Galanta. Nowadays, a research for the biggest geothermal project in the Middle Europe – construction in Košice basin has started.

Challenges in Smart Low-Temperature District Heating Development

DEFF Research Database (Denmark)

Li, Hongwei; Wang, Stephen Jia

2014-01-01

Previous research and development shows that low temperature district heating (LTDH) system is economic feasible for low energy buildings and buildings at sparse areas. Coupling with reduced network temperature and well-designed district heating (DH) networks, LTDH can reduce network heat loss by...

METHOD OF CALCULATING THE OPTIMAL HEAT EMISSION GEOTHERMAL WELLS

Directory of Open Access Journals (Sweden)

A. I. Akaev

2015-01-01

Full Text Available This paper presents a simplified method of calculating the optimal regimes of the fountain and the pumping exploitation of geothermal wells, reducing scaling and corrosion during operation. Comparative characteristics to quantify the heat of formation for these methods of operation under the same pressure at the wellhead. The problem is solved graphic-analytical method based on a balance of pressure in the well with the heat pump. 

THE PROPERTIES OF HOUSES IN TERMS OF GEOTHERMAL CENTRAL HEATING AND THE APPROACH OF DENIZLI TO GEOTHERMAL ENERGY

Directory of Open Access Journals (Sweden)

Halil KARAHAN

1996-01-01

Full Text Available Although the geothermal fluid, which is discharged into Büyük Menderes River after electric generation at Kızıldere Geothermal power plant, has been considered as a solution the air pollution problem of Denizli province, there has been no work carried out to determine the number of house, the area of house, the type of heating, coal consumption for each house, heat isolation, and centrally heated houses. The existing works includes only the applications at local places comparing to Denizli. In order to get maximum benefit from the planned project, it is necessary to collect data for Denizli and evaluate the data at the feasibility and application phases of the project. For this purpose questionnaire forms have been given to 15000 houses and offices at the different places in Denizli. The questionnaire forms were collected and the results have been evaluated and presented in graphics.

Planning of the district heating system in copenhagen from an economic perspective comparing energy-savings versus fossil-free supply

DEFF Research Database (Denmark)

Harrestrup, Maria; Svendsen, Svend

geothermal heating plants, may lead to oversized heating plants that are too expensive to build compared to implementing energy savings. Therefore reducing heat demand of existing buildings before investing in supply capacity will save society half the investment, indicating the importance of carrying out......The Danish government has adopted a long-term energy policy of being independent of fossil fuels by 2050, and that the energy supply for buildings should be independent of fossil fuels by 2035. Therefore, urgent action is needed to meet the requirements for the future energy system. One way...... of becoming independent of fossil fuels is to energy upgrade the existing building stock and change the energy supply to renewable energy sources. A sustainable way of providing space heating (SH) and domestic hot water (DHW) to buildings in densely populated areas is through the use of district heating (DH...

The radiation safety assessment of the heating loop of district heating reactors

International Nuclear Information System (INIS)

Liu Yuanzhong

1993-01-01

The district heating reactors are used to supply heating to the houses in cities. The concerned problems are whether the radioactive materials reach the heated houses through heating loop, and whether the safety of the dwellers can be ensured. In order to prevent radioactive materials getting into the heated houses, the district heating reactors have three loops, namely, primary loop, intermediate loop, and heating loop. In the paper, the measures of preventing radioactive materials getting into the heating loop are presented, and the possible sources of the radioactivity in the water of the intermediate loop and the heating loop are given. The regulatory aim limit of radioactive concentration in the water of the intermediate loop is put forward, which is 18.5 Bq/l. Assuming that specific radioactivity of the water of contaminated intermediate loop is up to 18.5 Bq/l, the maximum concentration of radionuclides in water of the heating loop is calculated for the normal operation and the accident of district heating reactor. The results show that the maximum possible concentration is 5.7 x 10 -3 Bq/l. The radiation safety assessment of the heating loop is made out. The conclusions are that the district heating reactors do not bring any harmful impact to the dwellers, and the safety of the dwellers can be safeguarded completely

Guidelines for District Heating Substations

Energy Technology Data Exchange (ETDEWEB)

2009-07-15

The present guidelines contain a set of recommendations focusing on planning, installation, use and maintenance of district heating (DH) substations within district heating systems throughout Europe. The recommendations were developed in order to enable readers to develop well-functioning substations and an effective heat and domestic warm water delivery. These guidelines are intended to give the most effective overall solutions for various parts of the customer installation. The guidelines are not meant to specify the different components of the substation such as meters or heat exchangers. The guidelines deal with a wide variety of issues concerning both present systems of today and district heating systems of the future. Specific handling and maintenance recommendations are mainly focused on present modern systems but are also intended to cover the future situation as much as is feasible. For this reason, certain existing systems are not dealt with in these guidelines. For instance, these guidelines do not cover steam systems, systems with temperatures exceeding 110 deg C and pressure levels above 1.6 MPa. The guidelines include a chapter on the heat meter, as the meter and especially the meter installation is always installed simultaneously with the rest of the substation. These guidelines aim to provide best-practice and easy-to-handle recommendations for: - those who are responsible for relations between district heating utilities and customers; - those who own or maintain a building connected to the district heating network; - those who manufacture, plan, purchase, test and install substations. These guidelines do not deal with investment or cost aspects, but in general, Euroheat and Power recommends looking at the lifetime cost of all components of the substation, instead of investment costs alone. An example of this is provided in Chapter 7.8. The Guidelines were developed based on the most optimal operating principles of substations and meters

Geothermal systems: Principles and case histories

Science.gov (United States)

Rybach, L.; Muffler, L. J. P.

The classification of geothermal systems is considered along with the geophysical and geochemical signatures of geothermal systems, aspects of conductive heat transfer and regional heat flow, and geothermal anomalies and their plate tectonic framework. An investigation of convective heat and mass transfer in hydrothermal systems is conducted, taking into account the mathematical modelling of hydrothermal systems, aspects of idealized convective heat and mass transport, plausible models of geothermal reservoirs, and preproduction models of hydrothermal systems. Attention is given to the prospecting for geothermal resources, the application of water geochemistry to geothermal exploration and reservoir engineering, heat extraction from geothermal reservoirs, questions of geothermal resource assessment, and environmental aspects of geothermal energy development. A description is presented of a number of case histories, taking into account the low enthalpy geothermal resource of the Pannonian Basin in Hungary, the Krafla geothermal field in Northeast Iceland, the geothermal system of the Jemez Mountains in New Mexico, and extraction-reinjection at the Ahuachapan geothermal field in El Salvador.

Human Health Science Building Geothermal Heat Pump Systems

Energy Technology Data Exchange (ETDEWEB)

Leidel, James [Oakland Univ., Rochester, MI (United States)

2014-12-22

The grant objectives of the DOE grant funded project have been successfully completed. The Human Health Building (HHB) was constructed and opened for occupancy for the Fall 2012 semester of Oakland University. As with any large construction project, some issues arose which all were overcome to deliver the project on budget and on time. The facility design is a geothermal / solar-thermal hybrid building utilizing both desiccant dehumidification and variable refrigerant flow heat pumps. It is a cooling dominant building with a 400 ton cooling design day load, and 150 ton heating load on a design day. A 256 vertical borehole (320 ft depth) ground source heat pump array is located south of the building under the existing parking lot. The temperature swing and performance over 2013 through 2015 shows the ground loop is well sized, and may even have excess capacity for a future building to the north (planned lab facility). The HHB achieve a US Green Building Counsel LEED Platinum rating by collecting 52 of the total 69 available LEED points for the New Construction v.2 scoring checklist. Being Oakland's first geothermal project, we were very pleased with the building outcome and performance with the energy consumption approximately 1/2 of the campus average facility, on a square foot basis.

Icebase: A suborbital survey to map geothermal heat flux under an ice sheet

Science.gov (United States)

Purucker, Michael E.; Connerney, John E. P.; Blakely, Richard J.; Bracken, Robert E.; Nowicki, Sophie; Le, Guan; Sabaka, Terence J.; Bonalsky, Todd M.; Kuang, Weijia; Ravat, Dhananjay; Ritz, Catherine; Vaughan, Alan P. M.; Gaina, Carmen; McEnroe, Suzanne; Lesur, Vincent

2013-04-01

NASA will solicit suborbital missions as part of its Earth Venture program element in the coming year. These missions are designed as complete PI-led investigations to conduct innovative hypothesis or scientific question-driven approaches to pressing questions in Earth System science. We propose to carry out a suborbital magnetic survey of Greenland using NASA's Global Hawk unmanned aerial vehicle to produce the first-ever map of the geothermal heat flux under an ice sheet. Better constraints on geothermal heat flux will reduce the uncertainty in future sea level rise, in turn allowing a more informed assessment of its impact on society. The geothermal heat flux depends on conditions such as mantle heat flux, and the tectonic history and heat production of the crust, all of which vary spatially. Underneath ice sheets, the geothermal heat flux influences the basal ice. Therefore heat flux is an important boundary condition in ice sheet modeling. Using magnetic data to constrain heat flux is possible because the magnetic properties of rocks are temperature dependent until they reach the Curie temperature. The technique has applications to understanding the response of Greenland ice sheet to climate forcing because the basal heat flux provides one of the boundary conditions. The technique also helps to locate the oldest ice. The oldest ice in Greenland should be found in areas of very low heat flux, and the identification of those areas is provided by this technique. Ice cores from the areas of oldest ice help to decipher past temperatures and CO2 contents. Our latest model of the geothermal heat flux under the Greenland ice sheet (http://websrv.cs.umt.edu/isis/index.php/Greenland_Basal_Heat_Flux) is based on low- resolution satellite observations collected by the CHAMP satellite between 2000 and 2010. Those observations will be enhanced by the upcoming Swarm gradient satellite mission, but the resolution will improve by less than a factor of two, from 400 km

An Information Survival Kit for the Prospective Geothermal Heat Pump Owner

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin

2001-02-01

The fact that you are considering a geothermal (or ground-source) heat pump system, places you among the best informed and most innovative homeowners in the country. Geothermal heat pumps (GHPs), although not a new technology, remain a small (but growing) player in the residential heating/cooling sector. Although somewhat higher in first cost, this technology can, in the right application, quickly repay this cost premium through savings in energy costs. Despite all the positive publicity on GHPs, they are not for everyone. Like any other heating and cooling system, GHPs tend to fit well in certain circumstances and poorly in others. Familiarizing yourself with the factors that effect the feasibility of GHPs will assist you in making an informed decision as to their suitability for your home. It is the intention of this package to provide that information and to address some of the commonly asked questions regarding the technology. Please feel free to contact us if you have questions not covered in this package.

Potentialities and type of integrating nuclear heating stations into district heating systems

International Nuclear Information System (INIS)

Munser, H.; Reetz, B.; Schmidt, G.

1978-01-01

Technical and economical potentialities of applying nuclear heating stations in district heating systems are discussed considering the conditions of the GDR. Special attention is paid to an optimum combination of nuclear heating stations with heat sources based on organic fuels. Optimum values of the contribution of nuclear heating stations to such combined systems and the economic power range of nuclear heating stations are estimated. Final considerations are concerned with the effect of siting and safety concepts of nuclear heating stations on the structure of the district heating system. (author)

Spatiotemporal and economic analysis of industrial excess heat as a resource for district heating

DEFF Research Database (Denmark)

Bühler, Fabian; Petrović, Stefan; Holm, Fridolin Müller

2018-01-01

detailed analysis of the most suitable types of industries and the costs is required, allowing a targeted exploitation of this resource. This work extends the spatial and thermodynamic analysis, to account for the temporal match between industrial excess heat and district heating demands, as well...... as the costs for implementation and operation of the systems. This allows the determination of cost-effective district heating potentials, as well as the analysis of different industries and technological requirements. The results show that the temporal mismatch between excess heat and district heating demand...... and lack of demand, reduces the theoretical substitution potential by almost 30%. If heat storages are introduced, the total potential is reduced by only 10%. A majority of the excess heat can be utilised at socio-economic heating costs lower than the average Danish district heating price and the cost...

Improving district heating in Kiev

International Nuclear Information System (INIS)

Salminen, P.

2000-01-01

The district heating modernisation project currently under way in Kiev, the capital of the Ukraine, is the largest project of its type financed by the World Bank. The budget for the five-year project is some USD 250 million of which USD 200 million is financed by the World Bank loan. The target of the project is to improve the city's district heating system, which is owned and operated by Kyivenergo. Consultancy services for the Project Implementation Unit are being provided by Electrowatt-Ekono and financed by the Finnish government

Flexible use of electricity in heat-only district heating plants

Directory of Open Access Journals (Sweden)

Erik Trømborg

2017-01-01

Full Text Available European energy systems are in a period of significant transition, with the increasing shares of variable renewable energy (VRE and less flexible fossil-based generation units as predominant factors. The supply-side changes are expected to cause large short-term electricity price volatility. More frequent periods of low electricity prices may mean that electric use in flexible heating systems will become more profitable, and such flexible heating systems may, in turn, improve the integration of increasing shares of VRE. The objective of this study is to analyze the likely future of Nordic electricity price levels and variations and how the expected prices might affect the use of electricity and thermal storage in heat-only district heating plants. We apply the North European energy market model Balmorel to provide scenarios for future hourly electricity prices in years with normal, high, and low inflow levels to the hydro power system. The simulation tool energyPRO is subsequently applied to quantify how these electricity price scenarios affect the hourly use of thermal storage and individual boilers in heat-only district heating plants located in Norway. The two studied example plants use wood chips or heat pump as base load representing common technologies for district heating in Norway. The Balmorel results show that annual differences in inflow is still a decisive factor for Norwegian and Nordic electricity prices in year 2030 and that short-term (daily price variability is expected to increase. In the plant-level simulations, we find that tank storage, which is currently installed in only a few district heating plants in Norway, is a profitable flexibility option that will significantly reduce the use of fossil peak load in both biomass and heat-pump-based systems. Installation of an electric boiler in addition to tank storage is profitable in the heat pump system due to the limited capacity of the heat pump. Electricity will hence, to a

District heating versus local heating - Social supportability

International Nuclear Information System (INIS)

Matei, Magdalena; Enescu, Diana; Varjoghie, Elena; Radu, Florin; Matei, Lucian

2004-01-01

District heating, DH, is an energy source which can provide a cost-effective, environmentally friendly source of heat and power for cities, but only in the case of well running systems, with reasonable technological losses. The benefits of DH system are well known: environmental friendly, energy security, economic and social advantages. DH already covers 60% of heating and hot water needs in transition economies. Today, 70 % of Russian, Latvian and Belarus homes use DH, and heating accounts for one-third of total Russian energy consumption. Yet a large number of DH systems in the region face serious financial, marketing or technical problems because of the policy framework. How can DH issues be best addressed in national and local policy? What can governments do to create the right conditions for the sustainable development of DH while improving service quality? What policies can help capture the economic, environmental and energy security benefits of co-generation and DH? To address these questions, the International Energy Agency (IEA) hosted in 2002 and 2004 conference focusing on the crucial importance of well-designed DH policies, for exchanging information on policy approaches. The conclusions of the conference have shown that 'DH systems can do much to save energy and boost energy security, but stronger policy measures are needed to encourage wise management and investment. With a stronger policy framework, DH systems in formerly socialist countries could save the equivalent of 80 billion cubic meters of natural gas a year through supply side efficiency improvements. This is greater than total annual natural gas consumption in Italy'. More efficient systems will also decrease costs, reducing household bills and making DH competitive on long-term. This paper presents the issues: -Theoretical benefits of the district heating and cooling systems; - Municipal heating in Romania; - Technical and economic problems of DH systems and social supportability; - How

Innovative system for delivery of low temperature district heating

OpenAIRE

Ianakiev, A; Cui, JM; Garbett, S; Filer, A

2017-01-01

An innovative low temperature district heating (LTDH) local network is developed in Nottingham, supported by the REMOURBAN project, part of the H2020 Smart City and Community Lighthouse scheme. It was proposed that a branch emanating from the return pipe of the existing district heating system in Nottingham would be created to use low temperature heating for the first time on such scale in the UK. The development is aimed to extract unused heat from existing district heating system and to mak...

Geothermal heating retrofit at the Utah State Prison Minimum Security Facility. Final report, March 1979-January 1986

Energy Technology Data Exchange (ETDEWEB)

1986-01-01

This report is a summary of progress and results of the Utah State Prison Geothermal Space Heating Project. Initiated in 1978 by the Utah State Energy Office and developed with assistance from DOE's Division of Geothermal and Hydropower Technologies PON program, final construction was completed in 1984. The completed system provides space and water heating for the State Prison's Minimum Security Facility. It consists of an artesian flowing geothermal well, plate heat exchangers, and underground distribution pipeline that connects to the existing hydronic heating system in the State Prison's Minimum Security Facility. Geothermal water disposal consists of a gravity drain line carrying spent geothermal water to a cooling pond which discharges into the Jordan River, approximately one mile from the well site. The system has been in operation for two years with mixed results. Continuing operation and maintenance problems have reduced the expected seasonal operation from 9 months per year to 3 months. Problems with the Minimum Security heating system have reduced the expected energy contribution by approximately 60%. To date the system has saved the prison approximately $18,060. The total expenditure including resource assessment and development, design, construction, performance verification, and reporting is approximately $827,558.

Solar-Enhanced Air-Cooled Heat Exchangers for Geothermal Power Plants

Directory of Open Access Journals (Sweden)

Kamel Hooman

2017-10-01

Full Text Available This paper focuses on the optimization of a Solar-Enhanced Natural-Draft Dry-Cooling Tower (SENDDCT, originally designed by the Queensland Geothermal Energy Centre of Excellence (QGECE, as the air-cooled condenser of a geothermal power plant. The conventional method of heat transfer augmentation through fin-assisted area extension is compared with a metal foam-wrapped tube bundle. Both lead to heat-transfer enhancement, albeit at the expense of a higher pressure drop when compared to the bare tube bundle as our reference case. An optimal design is obtained through the use of a simplified analytical model and existing correlations by maximizing the heat transfer rate with a minimum pressure drop goal as the constraint. Sensitivity analysis was conducted to investigate the effect of sunroof diameter, as well as tube bundle layouts and tube spacing, on the overall performance of the system. Aiming to minimize the flow and thermal resistances for a SENDDCT, an optimum design is presented for an existing tower to be equipped with solar panels to afterheat the air leaving the heat exchanger bundles, which are arranged vertically around the tower skirt. Finally, correlations are proposed to predict the total pressure drop and heat transfer of the extended surfaces considered here.

Report on fiscal 2000 survey for geothermal exploration technology verification. Survey of deep-seated geothermal resources; 2000 nendo chinetsu tansa gijutsu nado kensho chosa hokokusho. Shinbu chinetsu shigen chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

To promote the development of deep-seated geothermal resources in a rationalized way, studies are conducted about deep-seated geothermal resource assessment techniques, development guidelines, and the like. Data were collected at the Sumikawa-Onuma district, Ogiri district, Mori district, Yanaizu-Nishiyama district, and the Onikobe district, and compiled into a database to be open to the public. Studies were made about methods for estimating parameters for deep-seated geothermal reservoirs. The resultant findings indicate that, in the Uenotai and Sumikawa-Onuma districts where geothermal reservoirs are governed mainly by a fracture network, the relaxation method and extrapolation will be effective for deep-seated reservoir temperature estimation, and the ascending current analysis method and extrapolation for permeability estimation. The findings also indicate that the expanse of deep-seated reservoirs will be suitably estimated using a method similar to that applied to shallow-seated reservoirs. In the study of the estimation of the amount of deep-seated geothermal resources, it is concluded that the simplified model A will be effective in dealing with a geothermal district where there is a well-developed fracture network and the simplified model B in dealing with a geothermal district where supply of deep-seated fluid governed by an extensive fault prevails. (NEDO)

High radiogenic heat-producing Caenozoic granites: implications for the origin of Quman geothermal field in Taxkorgan, northwestern China

Science.gov (United States)

Shuai, W.; Shihua, Q.

2017-12-01

As a new found geothermal field, Quman geothermal field (Taxkorgan, China) holds a wellhead temperature of 144 ° and a shallow buried depth of heat reservoir. The heat source of the geothermal field is thought to be the heat flow from the upper mantle, which is disputable with the average Pamir Moho depth of 70 km. The new geochemical data of Taxkorgan alkaline complex, which is located to the west of the geothermal field and is exposed for 60 km along the western side of the Taxkorgan Valley, shed a light on the origin of Quman geothermal field. Together with the lithological association, the geochemical results present that Taxkorgan alkaline complex are mainly composed of alkaline syenites and subalkaline granitoids. Based on the contents of Th, U and K of 25 rock samples, the average radioactive heat generation of the complex (9.08 μW/m3) is 2 times of the standard of high heat production granites (HHPGs) (5 μW/m3), and 4 times of the average upper continental crust (UCC) heat production (2.7 μW/m3). According to U-Pd dating of zircon in aegirine-augite syenite, the crystallization age of the complex is 11 Ma. The complex has incompatible element abundances higher than generally observed for the continental crust, therefore a mantle source should be considered. The results of apatite fission track ange and track length of the complex indicate a low uplift rate (0.11 mm/a) in 3 5 Ma and a high uplift rate (2 3 mm/a) since ca. 2Ma, which indicates a low exposed age of the complex. Therefore, combined with previous studies, we propose that radioactive heat production of the complex and afterheat of magma cooling are the heat source of Quman geothermal field. With a shallow buried heat source, the geothermal field is potential for EGS development.

Low Temperature District Heating for Future Energy Systems

DEFF Research Database (Denmark)

Ford, Rufus; Pietruschka, Dirk; Sipilä, Kari

participants being VTT Technical Research Centre of Finland (VTT), Technical University of Denmark (DTU), Norwegian University of Science and Technology (NTNU), Stuttgart Technology University of Applied Sciences (HFT) and SSE Enterprise in United Kingdom. The demonstration cases described in the report......This report titled “Case studies and demonstrations” is the subtask D report of the IEA DHC|CHP Annex TS1 project “Low Temperature District Heating for Future Energy Systems” carried out between 2013 and 2016. The project was led by Fraunhofer Institute for Building Physics (IBP) with the other...... include examples on low temperature district heating systems, solar heating in a district heating system, heat pump based heat supply and energy storages for both peak load management and for seasonal heat storage. Some demonstrations have been implemented while others are at planning phase...

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

Kaliningrad regional district heating network 2004-2006. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-06-15

This report concerns: Kaliningrad Regional District Heating Network project which was implemented from 2004 to 2006. The task of the project was to establish and operate an association for district heating companies in the region in order to transfer and distribute district heating know-how to the sector and through activities strengthen the sector. The long term aim was to contribute to establishment of an association to continue as a real association for the heat supply companies in the region. (au)

District heating rehabilitation project. Viljandi - Estonia. Final report

International Nuclear Information System (INIS)

1998-04-01

The main objective of the project has been to assist Viljandi Municipality with the rehabilitation of their district heating system, and thereby to support the positive development of the district heating system in Viljandi to a more energy efficient and rational system and to achieve a significantly decrease in the pollution from the production of heat energy in Viljandi. The project has also included technical assistance to Viljandi DH company, in order to make them capable of operation and maintaining of the new substations, and also training of the local operational staff for operation of the complete district heating system. Viljandi is a county and is centrally located in Estonia, which makes Viljandi very suitable as recipient for a demonstration project. One important objective was the projects significantly positive environmental impact in reduction of the generated emissions of CO 2 , NO x and SO 2 , as the project includes installation of more efficient energy systems and supply of heat from the 2 existing district heating plants (both are partly fired with wood chips) instead of heating by very old and worn-out coal fired boilers and inexpedient designed substations with the present operational conditions. (EG)

District heating rehabilitation project. Viljandi - Estonia. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

The main objective of the project has been to assist Viljandi Municipality with the rehabilitation of their district heating system, and thereby to support the positive development of the district heating system in Viljandi to a more energy efficient and rational system and to achieve a significantly decrease in the pollution from the production of heat energy in Viljandi. The project has also included technical assistance to Viljandi DH company, in order to make them capable of operation and maintaining of the new substations, and also training of the local operational staff for operation of the complete district heating system. Viljandi is a county and is centrally located in Estonia, which makes Viljandi very suitable as recipient for a demonstration project. One important objective was the projects significantly positive environmental impact in reduction of the generated emissions of CO{sub 2}, NO{sub x} and SO{sub 2}, as the project includes installation of more efficient energy systems and supply of heat from the 2 existing district heating plants (both are partly fired with wood chips) instead of heating by very old and worn-out coal fired boilers and inexpedient designed substations with the present operational conditions. (EG)

Improving the performance of district heating systems by utilization of local heat boosters

DEFF Research Database (Denmark)

Falcone, A.; Dominkovic, D. F.; Pedersen, A. S.

was to evaluate the possibilities to lower the forward temperature of the heat supply in order to reduce the heat losses of the system. Booster heat pumps are introduced to increase the water temperature close to the final users. A Matlab model was developed to simulate the state of the case study DH network...... was set to minimize the system heat losses. * Corresponding author 0303-1 1 This goal was achieved by lowering the forward temperature to 40°C and relying on the installed heat pumps to boost the water temperature to the admissible value needed for the domestic hot water preparation. Depending......District Heating (DH) plays an important role into the Danish energy green transition towards the future sustainable energy systems. The new, 4 th generation district heating network, the so called Low Temperature District Heating (LTDH), tends to lower the supply temperature of the heat down to 40...

District heating and co-generation in Slovenia

International Nuclear Information System (INIS)

Hrovatin, Franc; Pecaric, Marko; Perovic, Olgica

2000-01-01

Recent development of district heating systems, gasification and co-generation processes in local communities in Slovenia as well as current status, potentials, possibilities and plans for further development in this sphere are presented. The current status presents energy production, distribution and use in district heating systems and in local gas distribution networks. An analysis of the energy and power generated and distributed in district power systems, made with regard to the size of the system, fuel used, type of consumers and the way of production, is given. Growth in different areas of local power systems in the period of last years is included. Potentials in the sphere of electrical energy and heat co-generation were assessed. Some possibilities and experience in heat energy storage are given and trends and plans for further development are introduced. (Authors)

Geothermal Heating, Convective Flow and Ice Thickness on Mars

Science.gov (United States)

Rosenberg, N. D.; Travis, B. J.; Cuzzi, J.

2001-01-01

Our 3D calculations suggest that hydrothermal circulation may occur in the martian regolith and may significantly thin the surface ice layer on Mars at some locations due to the upwelling of warm convecting fluids driven solely by background geothermal heating. Additional information is contained in the original extended abstract.

Heat demand mapping and district heating grid expansion analysis: Case study of Velika Gorica

Directory of Open Access Journals (Sweden)

Dorotić Hrvoje

2017-01-01

Full Text Available Highly efficient cogeneration and district heating systems have a significant potential for primary energy savings and the reduction of greenhouse gas emissions through the utilization of a waste heat and renewable energy sources. These potentials are still highly underutilized in most European countries. They also play a key role in the planning of future energy systems due to their positive impact on the increase of integration of intermittent renewable energy sources, for example wind and solar in a combination with power to heat technologies. In order to ensure optimal levels of district heating penetration into an energy system, a comprehensive analysis is necessary to determine the actual demands and the potential energy supply. Economical analysis of the grid expansion by using the GIS based mapping methods hasn’t been demonstrated so far. This paper presents a heat demand mapping methodology and the use of its output for the district heating network expansion analysis. The result are showing that more than 59% of the heat demand could be covered by the district heating in the city of Velika Gorica, which is two times more than the present share. The most important reason of the district heating's unfulfilled potential is already existing natural gas infrastructure.

Heat demand mapping and district heating grid expansion analysis: Case study of Velika Gorica

Science.gov (United States)

Dorotić, Hrvoje; Novosel, Tomislav; Duić, Neven; Pukšec, Tomislav

2017-10-01

Highly efficient cogeneration and district heating systems have a significant potential for primary energy savings and the reduction of greenhouse gas emissions through the utilization of a waste heat and renewable energy sources. These potentials are still highly underutilized in most European countries. They also play a key role in the planning of future energy systems due to their positive impact on the increase of integration of intermittent renewable energy sources, for example wind and solar in a combination with power to heat technologies. In order to ensure optimal levels of district heating penetration into an energy system, a comprehensive analysis is necessary to determine the actual demands and the potential energy supply. Economical analysis of the grid expansion by using the GIS based mapping methods hasn't been demonstrated so far. This paper presents a heat demand mapping methodology and the use of its output for the district heating network expansion analysis. The result are showing that more than 59% of the heat demand could be covered by the district heating in the city of Velika Gorica, which is two times more than the present share. The most important reason of the district heating's unfulfilled potential is already existing natural gas infrastructure.

Nuclear heat for industrial purposes and district heating

International Nuclear Information System (INIS)

1974-01-01

Studies on the various possibilities for the application of heat from nuclear reactors in the form of district heat or process steam for industrial purposes had been made long before the present energy crisis. Although these studies have indicated technical feasibility and economical justification of such utilization, the availability of relatively cheap oil and difficulties in locating a nuclear heat source inside industrial areas did not stimulate much further development. Since the increase of oil prices, the interest in nuclear heat application is reawakened, and a number of new potential areas have been identified. It now seems generally recognized that the heat from nuclear reactors should play an important role in primary energy supply, not only for electricity production but also as direct heat. At present three broad areas of nuclear heat application are identified: Direct heat utilization in industrial processing requiring a temperature above 800 deg. C; Process steam utilization in various industries, requiring a temperature mainly in the range of 200-300 deg. C; Low temperature and waste heat utilization from nuclear power plants for desalination of sea water and district heating. Such classification is mainly related to the type and characteristics of the heat source or nuclear reactor which could be used for a particular application. Modified high temperature reactor types (HTR) are the candidates for direct heat application, while the LWR reactors can satisfy most of the demands for process steam. Production of waste heat is a characteristic of all thermal power plants, and its utilization is a major challenge in the field of power production

Outline of geothermal activity in Czechoslovakia

International Nuclear Information System (INIS)

Franko, O.; Bodis, D.; Dendek, M.; Remsik, A.

1990-01-01

This paper reports that in respect of different geothermal conditions in the Bohemian Massif (unfavorable) and in the West Carpathians (favorable), the development and utilization of geothermal energy are concentrated in Slovakia. THe utilization of geothermal energy for the heating of buildings in spas commenced in 1958. Thermal energy of geothermal waters was used for direct heating through heat exchangers, and in one case by a heat pump. Concentrated continuous development and utilization of geothermal energy started in 1971

Monitoring of Building Heating and Cooling Systems Based on Geothermal Heat Pump in Galicia (Spain

Directory of Open Access Journals (Sweden)

Franco D.

2012-10-01

Full Text Available In November 2009 was signed an agreement between Galicia’s Government and EnergyLab to develop a project related with the geothermal heatpumps (hereafter, GSHP technology. That project consisted in replacing the existing thermal equipment generators (diesel boilers and air-water heat pumps by GSHP systems in representative public buildings: two nursery schools, a university library, a health centre and a residential building. This new systems will reach the demands of existing heating, cooling and domestic hot water (hereafter, DHW. These buildings can serve as examples of energy and economic savings that can offer this technology. We will show detailed analysis of the GSHP facilities monitored, since the starting-up of them. Which includes: COP’s, EER’s, energy consumption, operating costs, operation hours of the system, economic and emissions comparative, geothermal exchange evolution graphs, environmental conditions evolution graphs (temperature and demands, etc. The results presented show an example of the important benefits of the GSHP technology and the significant savings that can offer its implementation for heating, cooling and DHW production.

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.

Evaluation of soil thermal potential under Tunisian climate using a new conic basket geothermal heat exchanger: Energy and exergy analysis

International Nuclear Information System (INIS)

Boughanmi, Hassen; Lazaar, Mariem; Farhat, Abdelhamid; Guizani, Amenallah

2017-01-01

Highlights: • Conic geothermal basket heat exchanger (CBGHE) is experimentally investigated. • Charging and discharging processes of CBGHE are evaluated. • Energy and exergy efficiencies of CBGHE are performed. • High and stable performance of surface geothermal energy in Tunisia is established. - Abstract: Geothermal heat exchangers system composed of two conic baskets serially connected is designed and realized. Both heat exchangers are made in polyethylene high-density material and have a length of 3 m each one. They will be used for greenhouse cooling and heating through a geothermal heat pump. Its conical geometry is selected to reduce the operation cost and the exploited area, compared to vertical and horizontal geothermal heat exchangers often used. It also assures the maximum of heat exchange with the soil. The aim of this study is to determine the thermal performance of one Conic Basket Geothermal Heat Exchanger (CBGHE), buried at 3 m deep, in the exploitation of the soil thermal potential, in summer. A rate of heat exchange with the soil is determined and the global heat exchange of the CBGHE is assessed. Its energy and exergy efficiencies are also evaluated using both first and second law of thermodynamic. Results show that the specific heat exchange ranges between 20 W m"−"1 and 50 W m"−"1. Maximal energetic and exergetic efficiencies of the CBGHE, equal to 62% and 37% respectively, are reached for a mass flow rate of 0.1 kg s"−"1. For this value of mass flow rate, the overall heat exchange coefficient is of 52 W m"−"2 K"−"1.

Toward 4th generation district heating

DEFF Research Database (Denmark)

Li, Hongwei; Svendsen, Svend; Dalla Rosa, Alessandro

2014-01-01

In many countries, district heating (DH) has a key role in the national strategic energy planning. However, tighter legislation on new and future buildings requires much less heating demand which subsequently causes relative high network heat loss. This will make current DH system uneconomical co...