WorldWideScience

Sample records for model solar water

  1. Modelling heterogeneous interfaces for solar water splitting

    Science.gov (United States)

    Pham, Tuan Anh; Ping, Yuan; Galli, Giulia

    2017-04-01

    The generation of hydrogen from water and sunlight offers a promising approach for producing scalable and sustainable carbon-free energy. The key of a successful solar-to-fuel technology is the design of efficient, long-lasting and low-cost photoelectrochemical cells, which are responsible for absorbing sunlight and driving water splitting reactions. To this end, a detailed understanding and control of heterogeneous interfaces between photoabsorbers, electrolytes and catalysts present in photoelectrochemical cells is essential. Here we review recent progress and open challenges in predicting physicochemical properties of heterogeneous interfaces for solar water splitting applications using first-principles-based approaches, and highlights the key role of these calculations in interpreting increasingly complex experiments.

  2. Modelling heterogeneous interfaces for solar water splitting

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Tuan Anh; Ping, Yuan; Galli, Giulia

    2017-01-09

    The generation of hydrogen from water and sunlight others a promising approach for producing scalable and sustainable carbon-free energy. The key of a successful solar-to-fuel technology is the design of efficient, long-lasting and low-cost photoelectrochemical cells, which are responsible for absorbing sunlight and driving water splitting reactions. To this end, a detailed understanding and control of heterogeneous interfaces between photoabsorbers, electrolytes and catalysts present in photoelectrochemical cells is essential. Here we review recent progress and open challenges in predicting physicochemical properties of heterogeneous interfaces for solar water splitting applications using first-principles-based approaches, and highlights the key role of these calculations in interpreting increasingly complex experiments.

  3. Solar energy hot water heating and electric utilities. A model validation

    Science.gov (United States)

    1981-10-01

    TRNSYS is a residential solar simulation program designed to provide detailed simulations of individual solar systems composed of almost any presently used residential solar technology. The model is described and a validation of the model is presented using a group of domestic solar hot water systems in the metropolitan Philadelphia area. The collection and reduction of the data used is discussed, and the TRNSYS modeling of the systems is presented. The model results are given and a sensitivity analysis of the models was performed to determine the effect of input changes on the electric auxiliary backup consumption.

  4. Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems

    DEFF Research Database (Denmark)

    Qin, Lin

    1999-01-01

    This study focus on the analysis, modeling and simulation of solar domestic hot water(DHW) systems. Problems related to the system operation such as input weather data and hot water load conditions are also investigated.In order to investigate the heat loss as part of the total heat load, dynamic...... model of distribution network is developed and simulations are carried out for typical designed circulation type of distribution networks. For dynamic simulation of thermosyphon and drain-back solar DHW systems, thermosyphon loop model and drain-back tank model are put forward. Based on the simulations...

  5. A theoretical study of the modelling and control of a solar water electrolysis plant

    Science.gov (United States)

    Vandergeest, P.; Fahidy, T. Z.

    1980-01-01

    A control-oriented model is presented for a hydrogen producing plant consisting of a conventional water electrolysis process and a photo-assisted water electrolytic installation which utilizes solar energy via a suitable semiconductor/electrolyte assembly. A control strategy for daily hydrogen production is illustrated by a numerical example. The proposed simulation of solar water electrolysis plants is of potential usefulness for automatic control of the photoelectrolytic process when combined with statistical data-logging and model updating carried out in a practical installation.

  6. Simulation programs for ph.D. study of analysis, modeling and optimum design of solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Lin Qin

    1998-12-31

    The design of solar domestic hot water (DHW) systems is a complex process, due to characteristics inherent in the solar heating technology. Recently, computer simulation has become a widely used technique to improve the understanding of the thermal processes in such systems. One of the main objects of the Ph.D. study of `Analysis, Modelling and optimum Design of Solar Domestic Hot Water Systems` is to develop and verify programs for carrying out the simulation and evaluation of the dynamic performance of solar DHW systems. During this study, simulation programs for hot water distribution networks and for certain types of solar DHW systems were developed. (au)

  7. Modeling, Simulation, and Implementation of Solar-Driven Water-Splitting Devices.

    Science.gov (United States)

    Xiang, Chengxiang; Weber, Adam Z; Ardo, Shane; Berger, Alan; Chen, YiKai; Coridan, Robert; Fountaine, Katherine T; Haussener, Sophia; Hu, Shu; Liu, Rui; Lewis, Nathan S; Modestino, Miguel A; Shaner, Matthew M; Singh, Meenesh R; Stevens, John C; Sun, Ke; Walczak, Karl

    2016-10-10

    An integrated cell for the solar-driven splitting of water consists of multiple functional components and couples various photoelectrochemical (PEC) processes at different length and time scales. The overall solar-to-hydrogen (STH) conversion efficiency of such a system depends on the performance and materials properties of the individual components as well as on the component integration, overall device architecture, and system operating conditions. This Review focuses on the modeling- and simulation-guided development and implementation of solar-driven water-splitting prototypes from a holistic viewpoint that explores the various interplays between the components. The underlying physics and interactions at the cell level is are reviewed and discussed, followed by an overview of the use of the cell model to provide target properties of materials and guide the design of a range of traditional and unique device architectures.

  8. Modelling a directly coupled photovoltaic pumping system in a solar domestic hot water system

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Y.; Fraisse, G. [Savoy Univ., Le Bourget du lac (FR). Design Optimization and Environmental Engineering Laboratory (LOCIE)

    2008-07-01

    This paper presents a photovoltaic (PV) powered pumping system applying in a solar domestic hot water (SDHW) system. Two circulators ('Standard' and 'Solar') are employed respectively. A new model of circulator is developed in TRNSYS based on a 'Standard' type that consists of a DC-brushless motor and a centrifugal pump. Model validation is carried out by comparing with the experimental measurement. The experimental performance of these two circulators is analyzed on the aspects of startup and the stable operation stage. (orig.)

  9. Simulation Programs for Ph.D. Study of Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems

    DEFF Research Database (Denmark)

    Qin, Lin

    1999-01-01

    The design of solar domestic hot water system is a complex process, due to characteristics inherent in solar heating technology. Recently, computer simulation has become a widely used technique to improve the understanding of the thermal processes in such systems. This report presents the detailed...... programs or units that were developed in the Ph.D study of " Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems"....

  10. Calibrating an optimal condition model for solar water disinfection in peri-urban household water treatment in Kampala, Uganda.

    Science.gov (United States)

    Okurut, Kenan; Wozei, Eleanor; Kulabako, Robinah; Nabasirye, Lillian; Kinobe, Joel

    2013-03-01

    In low income settlements where the quality of drinking water is highly contaminated due to poor hygienic practices at community and household levels, there is need for appropriate, simple, affordable and environmentally sustainable household water treatment technology. Solar water disinfection (SODIS) that utilizes both the thermal and ultra-violet effect of solar radiation to disinfect water can be used to treat small quantities of water at household level to improve its bacteriological quality for drinking purposes. This study investigated the efficacy of the SODIS treatment method in Uganda and determined the optimal condition for effective disinfection. Results of raw water samples from the study area showed deterioration in bacteriological quality of water moved from source to the household; from 3 to 36 cfu/100 mL for tap water and 75 to 126 cfu/100 mL for spring water, using thermotolerant coliforms (TTCs) as indicator microorganisms. SODIS experiments showed over 99.9% inactivation of TTCs in 6 h of exposure, with a threshold temperature of 39.5 ± 0.7°C at about 12:00 noon, in the sun during a clear sunny day. A mathematical optimal condition model for effective disinfection has been calibrated to predict the decline of the number of viable microorganisms over time.

  11. Solar Hot Water Heater

    Science.gov (United States)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  12. Analysis, modeling and optimum design of solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Lin Qin

    1998-12-31

    The object of this study was dynamic modeling, simulation and optimum design of solar DHW (domestic hot water) systems, with respect to different whether conditions, and accurate dynamic behaviour of the heat load. Special attention was paid to systems with thermosyphon and drain-back design. The solar radiation in Beijing (China) and in Denmark are analyzed both by theoretical calculations and the analysis of long-term measurements. Based on the weather data from the Beijing Meteorological Station during the period of 1981-1993, a Beijing Test Reference Year has been formulated by means of statistical analysis. A brief introduction about the Danish Test Reference Year and the Design Reference Year is also presented. In order to investigate the heat loss as a part of the total heat load, dynamic models for distribution networks have been developed, and simulations have been carried out for typically designed distribution networks of the circulation type. The influence of operation parameters such as the tank outlet temperature, the hot-water load and the load pattern, on the heat loss from the distribution networks in presented. It was found that the tank outlet temperature has a significant influence on the heat loss from a circulation type of distribution network, while the hot-water load and the load pattern have no obvious effect. Dynamic models of drain-back tanks, both as a separated tank and combined with a mantle tank, have been developed and presented. Models of the other basic components commonly used in solar DHW systems, such as flat-plate collectors, connection pipes, storage tanks with a heat exchanger spiral, and controllers, are also described. (LN) 66 refs.

  13. Space Station solar water heater

    Science.gov (United States)

    Horan, D. C.; Somers, Richard E.; Haynes, R. D.

    1990-01-01

    The feasibility of directly converting solar energy for crew water heating on the Space Station Freedom (SSF) and other human-tended missions such as a geosynchronous space station, lunar base, or Mars spacecraft was investigated. Computer codes were developed to model the systems, and a proof-of-concept thermal vacuum test was conducted to evaluate system performance in an environment simulating the SSF. The results indicate that a solar water heater is feasible. It could provide up to 100 percent of the design heating load without a significant configuration change to the SSF or other missions. The solar heater system requires only 15 percent of the electricity that an all-electric system on the SSF would require. This allows a reduction in the solar array or a surplus of electricity for onboard experiments.

  14. A Groundwater Model to Assess Water Resource Impacts at the Imperial East Solar Energy Zone

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, John [Argonne National Lab. (ANL), Argonne, IL (United States); Greer, Chris [Argonne National Lab. (ANL), Argonne, IL (United States); O' Connor, Ben L. [Argonne National Lab. (ANL), Argonne, IL (United States); Tompson, Andrew F.B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-12-01

    The purpose of this study is to develop a groundwater flow model to examine the influence of potential groundwater withdrawal to support the utility-scale solar energy development at the Imperial East Solar Energy Zone (SEZ) as a part of the Bureau of Land Management’s (BLM) solar energy program.

  15. A Groundwater Model to Assess Water Resource Impacts at the Brenda Solar Energy Zone

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, John [Argonne National Lab. (ANL), Argonne, IL (United States); Carr, Adrianne E. [Argonne National Lab. (ANL), Argonne, IL (United States); Greer, Chris [Argonne National Lab. (ANL), Argonne, IL (United States); Bowen, Esther E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2013-12-01

    The purpose of this study is to develop a groundwater flow model to examine the influence of potential groundwater withdrawal to support utility-scale solar energy development at the Brenda Solar Energy Zone (SEZ), as a part of the Bureau of Land Management’s (BLM’s) Solar Energy Program.

  16. An Update of the Analytical Groundwater Modeling to Assess Water Resource Impacts at the Afton Solar Energy Zone

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, John J. [Argonne National Lab. (ANL), Argonne, IL (United States); Greer, Christopher B. [Argonne National Lab. (ANL), Argonne, IL (United States); Carr, Adrianne E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-10-01

    The purpose of this study is to update a one-dimensional analytical groundwater flow model to examine the influence of potential groundwater withdrawal in support of utility-scale solar energy development at the Afton Solar Energy Zone (SEZ) as a part of the Bureau of Land Management’s (BLM’s) Solar Energy Program. This report describes the modeling for assessing the drawdown associated with SEZ groundwater pumping rates for a 20-year duration considering three categories of water demand (high, medium, and low) based on technology-specific considerations. The 2012 modeling effort published in the Final Programmatic Environmental Impact Statement for Solar Energy Development in Six Southwestern States (Solar PEIS; BLM and DOE 2012) has been refined based on additional information described below in an expanded hydrogeologic discussion.

  17. Modelling of an ICS solar water heater using artificial neural networks and TRNSYS

    Energy Technology Data Exchange (ETDEWEB)

    Souliotis, M.; Tripanagnostopoulos, Y. [Physics Department, University of Patras, Patras 26504, ACHAIA (Greece); Kalogirou, S. [Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, P.O. Box 50329, Limassol 3603 (Cyprus)

    2009-05-15

    A study, in which a suitable artificial neural network (ANN) and TRNSYS are combined in order to predict the performance of an Integrated Collector Storage (ICS) prototype, is presented. Experimental data that have been collected from outdoor tests of an ICS solar water heater with cylindrical water storage tank inside a CPC reflector trough were used to train the ANN. The ANN is then used through the Excel interface (Type 62) in TRNSYS to model the annual performance of the system by running the model with the values of a typical meteorological year for Athens, Greece. In this way the specific capabilities of both approaches are combined, i.e., use of the radiation processing and modelling power of TRNSYS together with the 'black box' modelling approach of ANNs. The details of the calculation steps of both methods that aim to perform an accurate prediction of the system performance are presented and it is shown that this new method can be used effectively for such predictions. (author)

  18. Retrofitting Conventional Electric Domestic Hot Water Heaters to Solar Water Heating Systems in Single-Family Houses—Model Validation and Optimization

    Directory of Open Access Journals (Sweden)

    Luis R. Bernardo

    2013-02-01

    Full Text Available System cost reductions and development of standardised plug-and-function systems are some of the most important goals for solar heating technology development. Retrofitting hot water boilers in single-family houses when installing solar collectors has the potential to significantly reduce both material and installation costs. In this study, the TRNSYS simulation models of the retrofitting solar thermal system were validated against measurements. Results show that the validated models are in good agreement with measurements. On an annual basis a deviation of 2.5% out of 1099 kWh was obtained between the auxiliary energy from results and from the simulation model for a complete system. Using the validated model a system optimization was carried out with respect to control strategies for auxiliary heating, heat losses and volume of auxiliary storage. A sensitivity analysis was carried out regarding different volumes of retrofitted hot water boiler, DHW profiles and climates. It was estimated that, with adequate improvements, extended annual solar fractions of 60%, 78% and 81% can be achieved for Lund (Sweden, Lisbon (Portugal and Lusaka (Zambia, respectively. The correspondent collector area was 6, 4 and 3 m2, respectively. The studied retrofitted system achieves a comparable performance with conventional solar thermal systems with the potential to reduce the investment cost.

  19. Solar water splitting: efficiency discussion

    CERN Document Server

    Juodkazyte, Jurga; Sebeka, Benjaminas; Savickaja, Irena; Malinauskas, Tadas; Badokas, Kazimieras; Juodkazis, Kestutis; Juodkazis, Saulius

    2016-01-01

    The current state of the art in direct water splitting in photo-electrochemical cells (PECs) is presented together with: (i) a case study of water splitting using a simple solar cell with the most efficient water splitting electrodes and (ii) a detailed mechanism analysis. Detailed analysis of the energy balance and efficiency of solar hydrogen production are presented. The role of hydrogen peroxide formation as an intermediate in oxygen evolution reaction is newly revealed and explains why an oxygen evolution is not taking place at the thermodynamically expected 1.23 V potential. Solar hydrogen production with electrical-to-hydrogen conversion efficiency of 52% is demonstrated using a simple ~0.7%-efficient n-Si/Ni Schottky solar cell connected to a water electrolysis cell. This case study shows that separation of the processes of solar harvesting and electrolysis avoids photo-electrode corrosion and utilizes optimal electrodes for hydrogen and oxygen evolution reactions and achieves ~10% efficiency in light...

  20. Solar water splitting: efficiency discussion

    OpenAIRE

    Juodkazyte, Jurga; Seniutinas, Gediminas; Sebeka, Benjaminas; Savickaja, Irena; Malinauskas, Tadas; Badokas, Kazimieras; Juodkazis, Kestutis; Juodkazis, Saulius

    2016-01-01

    The current state of the art in direct water splitting in photo-electrochemical cells (PECs) is presented together with: (i) a case study of water splitting using a simple solar cell with the most efficient water splitting electrodes and (ii) a detailed mechanism analysis. Detailed analysis of the energy balance and efficiency of solar hydrogen production are presented. The role of hydrogen peroxide formation as an intermediate in oxygen evolution reaction is newly revealed and explains why a...

  1. Determination of rational design parameters of a multi-stage solar water desalination still using transient mathematical modelling

    Energy Technology Data Exchange (ETDEWEB)

    Shatat, M.I.M.; Mahkamov, K. [School of Engineering, Durham University, South Road, Durham, DH1 3LE (United Kingdom)

    2010-01-15

    The paper describes the experimental investigations of the performance of a multi-stage water desalination still connected to a heat pipe evacuated tube solar collector with aperture area of 1.7 m{sup 2}. The multi-stage solar still water desalination system was designed to recover latent heat from evaporation and condensation processes in four stages. The variation in the solar radiation during a typical mid-summer day in the Middle East region was simulated on the test rig using an array of 110 halogen floodlights covering the area of the collector. The results of tests demonstrate that the system produces about 9 kg of fresh water per day and has a solar collector efficiency of about 68%. However, the overall efficiency of the laboratory test rig at this stage of the investigations was found to be at the level of 33% due to excessive heat losses in the system. The analysis of the distilled water showed that its quality was within the World Health Organization guidelines. The still's operation was numerically simulated by employing a mathematical model based on a system of ordinary energy and mass conservation differential equations written for each stage of the still. A computer program was developed for transient simulations of the evaporation and condensation processes inside the multi-stage still. Experimental results obtained and theoretical predictions were found to be in good agreement. The results on the determination of rational design dimensions and number of stages of the still for a given aperture of the solar collector are also presented in this work. (author)

  2. Global water cycle and solar activity variations

    Science.gov (United States)

    Al-Tameemi, Muthanna A.; Chukin, Vladimir V.

    2016-05-01

    The water cycle is the most active and most important component in the circulation of global mass and energy in the Earth system. Furthermore, water cycle parameters such as evaporation, precipitation, and precipitable water vapour play a major role in global climate change. In this work, we attempt to determine the impact of solar activity on the global water cycle by analyzing the global monthly values of precipitable water vapour, precipitation, and the Solar Modulation Potential in 1983-2008. The first object of this study was to calculate global evaporation for the period 1983-2008. For this purpose, we determined the water cycle rate from satellite data, and precipitation/evaporation relationship from 10 years of Planet Simulator model data. The second object of our study was to investigate the relationship between the Solar Modulation Potential (solar activity index) and the evaporation for the period 1983-2008. The results showed that there is a relationship between the solar modulation potential and the evaporation values for the period of study. Therefore, we can assume that the solar activity has an impact on the global water cycle.

  3. Solar radiation models - review

    Directory of Open Access Journals (Sweden)

    M. Jamil Ahmad, G.N. Tiwari

    2010-05-01

    Full Text Available In the design and study of solar energy, information on solar radiation and its components at a given location is very essential. Solar radiation data are required by solar engineers, architects, agriculturists and hydrologists for many applications such as solar heating, cooking, drying and interior illumination of buildings. For this purpose, in the past, several empirical correlations have been developed in order to estimate the solar radiation around the world. The main objective of this study is to review the global solar radiation models available in the literature. There are several formulae which relate global radiation to other climatic parameters such as sunshine hours, relative humidity and maximum temperature. The most commonly used parameter for estimating global solar radiation is sunshine duration. Sunshine duration can be easily and reliably measured and data are widely available.

  4. Thermal modeling of a combined system of photovoltaic thermal (PV/T) solar water heater

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Swapnil; Tiwari, G.N. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2008-07-15

    In this paper, an integrated combined system of a photovoltaic (glass-glass) thermal (PV/T) solar water heater of capacity 200 l has been designed and tested in outdoor condition for composite climate of New Delhi. An analytical expression for characteristic equation for photovoltaic thermal (PV/T) flat plate collector has been derived for different condition as a function of design and climatic parameters. The testing of collector and system were carried out during February-April, 2007. It is observed that the photovoltaic thermal (PV/T) flat plate collector partially covered with PV module gives better thermal and average cell efficiency which is in accordance with the results reported by earlier researchers. (author)

  5. Solar water heater design package

    Science.gov (United States)

    1981-01-01

    Package describes commercial domestic-hot-water heater with roof or rack mounted solar collectors. System is adjustable to pre-existing gas or electric hot-water house units. Design package includes drawings, description of automatic control logic, evaluation measurements, possible design variations, list of materials and installation tools, and trouble-shooting guide and manual.

  6. Modeling of solar polygeneration plant

    Science.gov (United States)

    Leiva, Roberto; Escobar, Rodrigo; Cardemil, José

    2017-06-01

    In this work, a exergoeconomic analysis of the joint production of electricity, fresh water, cooling and process heat for a simulated concentrated solar power (CSP) based on parabolic trough collector (PTC) with thermal energy storage (TES) and backup energy system (BS), a multi-effect distillation (MED) module, a refrigeration absorption module, and process heat module is carried out. Polygeneration plant is simulated in northern Chile in Crucero with a yearly total DNI of 3,389 kWh/m2/year. The methodology includes designing and modeling a polygeneration plant and applying exergoeconomic evaluations and calculating levelized cost. Solar polygeneration plant is simulated hourly, in a typical meteorological year, for different solar multiple and hour of storage. This study reveals that the total exergy cost rate of products (sum of exergy cost rate of electricity, water, cooling and heat process) is an alternative method to optimize a solar polygeneration plant.

  7. Modeling, simulation, and fabrication of a fully integrated, acid-stable, scalable solar-driven water-splitting system.

    Science.gov (United States)

    Walczak, Karl; Chen, Yikai; Karp, Christoph; Beeman, Jeffrey W; Shaner, Matthew; Spurgeon, Joshua; Sharp, Ian D; Amashukeli, Xenia; West, William; Jin, Jian; Lewis, Nathan S; Xiang, Chengxiang

    2015-02-01

    A fully integrated solar-driven water-splitting system comprised of WO3 /FTO/p(+) n Si as the photoanode, Pt/TiO2 /Ti/n(+) p Si as the photocathode, and Nafion as the membrane separator, was simulated, assembled, operated in 1.0 M HClO4 , and evaluated for performance and safety characteristics under dual side illumination. A multi-physics model that accounted for the performance of the photoabsorbers and electrocatalysts, ion transport in the solution electrolyte, and gaseous product crossover was first used to define the optimal geometric design space for the system. The photoelectrodes and the membrane separators were then interconnected in a louvered design system configuration, for which the light-absorbing area and the solution-transport pathways were simultaneously optimized. The performance of the photocathode and the photoanode were separately evaluated in a traditional three-electrode photoelectrochemical cell configuration. The photocathode and photoanode were then assembled back-to-back in a tandem configuration to provide sufficient photovoltage to sustain solar-driven unassisted water-splitting. The current-voltage characteristics of the photoelectrodes showed that the low photocurrent density of the photoanode limited the overall solar-to-hydrogen (STH) conversion efficiency due to the large band gap of WO3 . A hydrogen-production rate of 0.17 mL hr(-1) and a STH conversion efficiency of 0.24 % was observed in a full cell configuration for >20 h with minimal product crossover in the fully operational, intrinsically safe, solar-driven water-splitting system. The solar-to-hydrogen conversion efficiency, ηSTH , calculated using the multiphysics numerical simulation was in excellent agreement with the experimental behavior of the system. The value of ηSTH was entirely limited by the performance of the photoelectrochemical assemblies employed in this study. The louvered design provides a robust platform for implementation of various types of

  8. TOWARDS A UTAUT-BASED MODEL FOR THE INTENTION TO USE SOLAR WATER HEATERS BY LIBYAN HOUSEHOLDS

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Saleh

    2014-01-01

    Full Text Available Among the most fundamental features to ensure the success of a new technology introduction is citizen acceptance. Based on a unified model, called the Unified Theory of Adoption and Use of Technology (UTAUT, this paper provides new insights into predicting adoption and identifying of the factors that may prompt people to accept and use of Solar Water Heaters as a concrete step toward using Renewable Energy Resources, and offer guidelines for energy saving for the Libyan government and that will contribute to the economy of the country.

  9. Study on solar sea water desalination; Studie ueber solare Meerwasserentsalzung

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, G.K.

    1995-09-01

    The state of the art of solar sea water desalination is discussed based on the example of simple solar distillation. Reasons are given for the relatively reserved use of this technique in the past. The increasing shortage of fresh water (drinking water) due to increasing water consumption, the deforestation of (rain) forests, and increasing environmental pollution reveals the urgency of sea water desalination. However, the fossil energy sources that are needed for desalination cause a further increase in carbon dioxide emissions and aggravate the global-warming problem. This study suggests to multiply the relatively low economic efficiency and low cost efficiency of simple solar distillers by vacuum-controlled ground cooling and to operate pumps that convey sea water and distilled water by means of solar energy or solar cogeneration. Model calculations and a pilot project are recommended for a closer quantification of the data. General intercultural and socioeconomic aspects that must be considered when installing solar sea water (waste water) distillation plants, e.g. in Africa, are discussed. (orig.) [Deutsch] In dieser Studie wird der Stand der Technik der solaren Wasserentsalzung, basierend auf der einfachen solaren Destillation, untersucht sowie die Gruende fuer den bisher relativ geringen Einsatz dieser Technik erlaeutert. Die zunehmende Verknappung von Suesswasser (Trinkwasser), durch steigenden Wasserverbrauch, durch die Abholzung von (Regen)-Waeldern und durch die zunehmende Umweltverschmutzung ruecken aber die Notwendigkeit der Meerwasserentsalzung immer staerker in den Vordergrund. Der hohe Energiebedarf dafuer traegt aber bei der Verwendung von fossiler Primaerenergie zu einer weiteren Verstaerkung des CO{sub 2}-Ausstosses und damit zur weiteren Verschaerfung der Klimaproblematik bei. Deshalb wird hier nicht nur vorgeschlagen, den relativ geringen Wirkungsgrad und die relativ geringe Kosteneffizienz einfacher solarer Destillatoren durch

  10. A Parameterized yet Accurate Model of Ozone and Water Vapor Transmittance in the Solar-to-near-infrared Spectrum

    Institute of Scientific and Technical Information of China (English)

    LIU Weiyi; QIU Jinhuan

    2012-01-01

    A parameterized transmittance model (PTR) for ozone and water vapor monochromatic transmittance calculation in the solar-to-near-infrared spectrum 0.3-4 μm with a spectral resolution of 5 cm-1 was developed based on the transmittance data calculated by Moderate-resolution Transmittance model (MODTRAN).Polynomial equations were derived to represent the transmittance as functions of path length and airmass for every wavelength based on the least-squares method.Comparisons between the transmittances calculated using PTR and MODTRAN were made,using the results of MODTRAN as a reference.Relative root-mean-square error (RMSre) was 0.823% for ozone transmittance.RMSre values were 8.84% and 3.48% for water vapor transmittance ranges of 1-1 × 10-18and 1-1× 10-3,respectively.In addition,the Stratospheric Aerosol and Gas Experiment II (SAGEII) ozone profiles and University of Wyoming (UWYO)water vapor profiles were applied to validate the applicability of PTR model.RMSre was 0.437% for ozone transmittance.RMSre values were 8.89% and 2.43% for water vapor transmittance ranges of 1-1 × 10-18and 1-1 × 10-6,respectively.Furthermore,the optical depth profiles calculated using the PTR model were compared to the results of MODTRAN.Absolute RMS errors (RMSab) for ozone optical depths were within 0.0055 and 0.0523 for water vapor at all of the tested altitudes.Finally,the comparison between the solar heating rate calculated from the transmittance of PTR and Line-by-Line radiative transfer model (LBLRTM) was performed,showing a maximum deviation of 0.238 K d-1 (6% of the corresponding solar heating rate calculated using LBLRTM).In the troposphere all of the deviations were within 0.08 K d-1.The computational speed of PTR model is nearly two orders of magnitude faster than that of MODTRAN.

  11. Water in the Solar System

    Science.gov (United States)

    Encrenaz, Thérèse

    2008-09-01

    Water is ubiquitous in the Universe, and also in the Solar System. By setting the snow line at its condensation level in the protosolar disk, water was responsible for separating the planets into the terrestrial and the giant ones. Water ice is a major constituent of the comets and the small bodies of the outer Solar System, and water vapor is found in the giant planets, both in their interiors and in the stratospheres. Water is a trace element in the atmospheres of Venus and Mars today. It is very abundant on Earth, mostly in liquid form, but it was probably also abundant in the primitive atmospheres of Venus and Mars. Water is found in different states on the three planets, as vapor on Venus and ice (or permafrost) on Mars. Most likely, this difference has played a major role in the diverging destinies of the three planets.

  12. Solar insolation model

    Science.gov (United States)

    Smith, J. H.

    1980-01-01

    Computer program SOLINS helps engineers with relatively complex task of choosing best orientation of fixed flat-plate solar collectors for local conditions. Program models average hourly solar insolation on fixed but arbitrarily-oriented surface. Consideration is given to problems of array spacing, shadowing, and use of augmentation reflectors to increase insolation at collector surface.

  13. Solar power water distillation unit

    Science.gov (United States)

    Hameed, Kamran; Muzammil Khan, Muhammad; Shahrukh Ateeq, Ijlal; Omair, Syed Muhammad; Ahmer, Muhammad; Wajid, Abdul

    2013-06-01

    Clean drinking water is the basic necessity for every human being, but about 1.1 billion people in the world lacked proper drinking water. There are many different types of water purification processes such as filtration, reverse osmosis, ultraviolet radiation, carbon absorption, but the most reliable processes are distillation and boiling. Water purification, such as distillation, is especially important in regions where water resources or tap water is not suitable for ingesting without boiling or chemical treatment. In design project It treats the water by combining different methods such as Filtration, Distillation and a technique called concentrated solar power (CSP). Distillation is literally the method seen in nature, whereby: the sun heats the water on the earth's surface, the water is turned into a vapor (evaporation) and rises, leaving contaminants behind, to form clouds. As the upper atmosphere drops in temperature the vapors cool and convert back to water to form water. In this project distillation is achieved by using a parabolic mirror which boils water at high temperature. Filtration is done by sand filter and carbon filter. First sand filter catches the sand particles and the carbon filter which has granules of active carbon is used to remove odor dissolved gases from water. This is the Pre-treatment of water. The filtered water is then collected in a water container at a focus of parabolic mirror where distillation process is done. Another important feature of designed project is the solar tracking of a parabolic mirror which increases the efficiency of a parabolic mirror [1],[2].

  14. Solar-Powered Water Distillation

    Science.gov (United States)

    Menninger, F. J.; Elder, R. J.

    1985-01-01

    Solar-powered still produces pure water at rate of 6,000 gallons per year. Still fully automatic and gravity-fed. Only outside electric power is timer clock and solenoid-operated valve. Still saves $5,000 yearly in energy costs and pays for itself in 3 1/2 years.

  15. Modeling of Solar Concentrators

    Science.gov (United States)

    Rockey, D. E.

    1984-01-01

    Algorithm developed for predicting power output, uniformity of intensity and operating temperature of concentrator-enhanced photovoltaic solar cell arrays. Optimum values for parameters such as reflector geometry found prior to constructing scale models for testing.

  16. The origin of inner Solar System water.

    Science.gov (United States)

    Alexander, Conel M O'D

    2017-05-28

    Of the potential volatile sources for the terrestrial planets, the CI and CM carbonaceous chondrites are closest to the planets' bulk H and N isotopic compositions. For the Earth, the addition of approximately 2-4 wt% of CI/CM material to a volatile-depleted proto-Earth can explain the abundances of many of the most volatile elements, although some solar-like material is also required. Two dynamical models of terrestrial planet formation predict that the carbonaceous chondrites formed either in the asteroid belt ('classical' model) or in the outer Solar System (5-15 AU in the Grand Tack model). To test these models, at present the H isotopes of water are the most promising indicators of formation location because they should have become increasingly D-rich with distance from the Sun. The estimated initial H isotopic compositions of water accreted by the CI, CM, CR and Tagish Lake carbonaceous chondrites were much more D-poor than measured outer Solar System objects. A similar pattern is seen for N isotopes. The D-poor compositions reflect incomplete re-equilibration with H2 in the inner Solar System, which is also consistent with the O isotopes of chondritic water. On balance, it seems that the carbonaceous chondrites and their water did not form very far out in the disc, almost certainly not beyond the orbit of Saturn when its moons formed (approx. 3-7 AU in the Grand Tack model) and possibly close to where they are found today.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

  17. Exploring the Effects of Solar Radiation Management on Water Cycling in a Coupled Land-Atmosphere Model

    Science.gov (United States)

    Dagon, K.; Schrag, D. P.

    2015-12-01

    Solar radiation management (SRM) has been proposed as a form of geoengineering to reduce the warming effects of anthropogenic greenhouse gas emissions. Modeling studies have concluded that SRM roughly compensates for global mean temperature changes induced by greenhouse gas forcing, while large-scale hydrologic cycle changes persist. This is driven by both the sensitivity of surface energy fluxes to changes in shortwave versus longwave radiation, and the physiological effect of carbon dioxide on vegetation. We explore the impact of SRM on the hydrologic cycle that may contribute to local and regional temperature and temperature variability. Regional and seasonal changes are examined under simulations using the Community Land Model, version 4, with reductions in solar radiation relative to simulations with present-day and elevated CO2 concentrations. There are significant regional impacts due to vegetation-climate interactions that are not compensated under SRM, including changes in evapotranspiration, soil moisture, and runoff. In the tropics, evapotranspiration decreases due to increased vegetation water use efficiency, increasing soil moisture. In northern mid-latitudes, decreases in evapotranspiration do not always translate to increases in soil moisture due in part to the precipitation response. These results imply that SRM does not compensate for higher greenhouse gas concentrations when one considers land-atmosphere interactions.

  18. Solar water heater for NASA's Space Station

    Science.gov (United States)

    Somers, Richard E.; Haynes, R. Daniel

    1988-01-01

    The feasibility of using a solar water heater for NASA's Space Station is investigated using computer codes developed to model the Space Station configuration, orbit, and heating systems. Numerous orbit variations, system options, and geometries for the collector were analyzed. Results show that a solar water heater, which would provide 100 percent of the design heating load and would not impose a significant impact on the Space Station overall design is feasible. A heat pipe or pumped fluid radial plate collector of about 10-sq m, placed on top of the habitat module was found to be well suited for satisfying water demand of the Space Station. Due to the relatively small area required by a radial plate, a concentrator is unnecessary. The system would use only 7 to 10 percent as much electricity as an electric water-heating system.

  19. A modeling approach to estimate the solar disinfection of viral indicator organisms in waste stabilization ponds and surface waters.

    Science.gov (United States)

    Kohn, Tamar; Mattle, Michael J; Minella, Marco; Vione, Davide

    2016-01-01

    Sunlight is known to be a pertinent factor governing the infectivity of waterborne viruses in the environment. Sunlight inactivates viruses via endogenous inactivation (promoted by absorption of solar light in the UVB range by the virus) and exogenous processes (promoted by adsorption of sunlight by external chromophores, which subsequently generate inactivating reactive species). The extent of inactivation is still difficult to predict, as it depends on multiple parameters including virus characteristics, solution composition, season and geographical location. In this work, we adapted a model typically used to estimate the photodegradation of organic pollutants, APEX, to explore the fate of two commonly used surrogates of human viruses (coliphages MS2 and ϕX174) in waste stabilization pond and natural surface water. Based on experimental data obtained in previous work, we modeled virus inactivation as a function of water depth and composition, as well as season and latitude, and we apportioned the contributions of the different inactivation processes to total inactivation. Model results showed that ϕX174 is inactivated more readily than MS2, except at latitudes >60°. ϕX174 inactivation varies greatly with both season (20-fold) and latitude (10-fold between 0 and 60°), and is dominated by endogenous inactivation under all solution conditions considered. In contrast, exogenous processes contribute significantly to MS2 inactivation. Because exogenous inactivation can be promoted by longer wavelengths, which are less affected by changes in season and latitude, MS2 exhibits smaller fluctuations in inactivation throughout the year (10-fold) and across the globe (3-fold between 0 and 60°) compared to ϕX174. While a full model validation is currently not possible due to the lack of sufficient field data, our estimated inactivation rates corresponded well to those reported in field studies. Overall, this study constitutes a step toward estimating microbial water

  20. Basics of Solar Heating & Hot Water Systems.

    Science.gov (United States)

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

  1. Innovative solar thermochemical water splitting.

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, Roy E. Jr.; Siegel, Nathan P.; Evans, Lindsey R.; Moss, Timothy A.; Stuecker, John Nicholas (Robocasting Enterprises, Albuquerque, NM); Diver, Richard B., Jr.; Miller, James Edward; Allendorf, Mark D. (Sandia National Laboratories, Livermore, CA); James, Darryl L. (Texas Tech University, Lubbock, TX)

    2008-02-01

    Sandia National Laboratories (SNL) is evaluating the potential of an innovative approach for splitting water into hydrogen and oxygen using two-step thermochemical cycles. Thermochemical cycles are heat engines that utilize high-temperature heat to produce chemical work. Like their mechanical work-producing counterparts, their efficiency depends on operating temperature and on the irreversibility of their internal processes. With this in mind, we have invented innovative design concepts for two-step solar-driven thermochemical heat engines based on iron oxide and iron oxide mixed with other metal oxides (ferrites). The design concepts utilize two sets of moving beds of ferrite reactant material in close proximity and moving in opposite directions to overcome a major impediment to achieving high efficiency--thermal recuperation between solids in efficient counter-current arrangements. They also provide inherent separation of the product hydrogen and oxygen and are an excellent match with high-concentration solar flux. However, they also impose unique requirements on the ferrite reactants and materials of construction as well as an understanding of the chemical and cycle thermodynamics. In this report the Counter-Rotating-Ring Receiver/Reactor/Recuperator (CR5) solar thermochemical heat engine and its basic operating principals are described. Preliminary thermal efficiency estimates are presented and discussed. Our ferrite reactant material development activities, thermodynamic studies, test results, and prototype hardware development are also presented.

  2. Solar Water-Heater Design Package

    Science.gov (United States)

    1982-01-01

    Information on a solar domestic-hot water heater is contained in 146 page design package. System consists of solar collector, storage tanks, automatic control circuitry and auxiliary heater. Data-acquisition equipment at sites monitors day-by-day performance. Includes performance specifications, schematics, solar-collector drawings and drawings of control parts.

  3. Smart solar tanks for small solar domestic hot water systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Andersen, Elsa; Knudsen, Søren

    2005-01-01

    Investigation of small SDHW systems based on smart solar tanks are presented. The domestic water in a smart solar tank can be heated both by solar collectors and by means of an auxiliary energy supply system. The auxiliary energy supply system – in this study electric heating elements – heats up...... systems, based on differently designed smart solar tanks and a traditional SDHW system were investigated by means of laboratory experiments and theoretical calculations. The investigations showed that the yearly thermal performance of SDHW systems with smart solar tanks is 5-35% higher than the thermal...... performance of traditional SDHW systems. Estimates indicate that the performance/cost ratio can be improved by up to 25% by using a smart solar tank instead of a traditional tank when the backup energy system is electric heating elements. Further, smart solar tanks are suitable for unknown, variable, large...

  4. Large scale water lens for solar concentration.

    Science.gov (United States)

    Mondol, A S; Vogel, B; Bastian, G

    2015-06-01

    Properties of large scale water lenses for solar concentration were investigated. These lenses were built from readily available materials, normal tap water and hyper-elastic linear low density polyethylene foil. Exposed to sunlight, the focal lengths and light intensities in the focal spot were measured and calculated. Their optical properties were modeled with a raytracing software based on the lens shape. We have achieved a good match of experimental and theoretical data by considering wavelength dependent concentration factor, absorption and focal length. The change in light concentration as a function of water volume was examined via the resulting load on the foil and the corresponding change of shape. The latter was extracted from images and modeled by a finite element simulation.

  5. Solar photocatalytic degradation of resorcinol a model endocrine disrupter in water using zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Pardeshi, S.K. [Department of Chemistry, University of Pune, Ganeshkhind, Pune 411007 (India)], E-mail: skpar@chem.unipune.ernet.in; Patil, A.B. [Department of Chemistry, University of Pune, Ganeshkhind, Pune 411007 (India)

    2009-04-15

    Photocatalytic degradation (PCD) of resorcinol a potent endocrine disrupting chemical in aqueous medium was investigated by ZnO under sunlight irradiation in a batch photoreactor. The influence of various parameters such as photocatalyst amount, initial concentration of resorcinol and pH was examined for maximum PCD of resorcinol. A considerable influence of pH upon the chemical oxygen demand (COD) disappearance was observed. In general, neutral or basic pH is favorable for COD removal of resorcinol. PCD intermediates were identified using FTIR and GC/MS. Two of the initial oxidation intermediates detected were 1,2,4-trihydroxy-benzene and 1,2,3-trihydroxy-benzene. FTIR studies revealed 1,2,4-trihydroxy-benzene as the major PCD intermediate. A working photodegradation mechanism is also suggested for PCD of resorcinol. This work envisages the great potential that sunlight mediated photocatalysis has in the removal of resorcinol from waste water.

  6. OUT Success Stories: Solar Hot Water Technology

    Science.gov (United States)

    Clyne, R.

    2000-08-01

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building.

  7. Intelligent annunciator for solar water heater

    Science.gov (United States)

    Chen, Xiao

    2009-07-01

    The solar water heater has advantages of low cost, no pollution, safety, energy conservation and is very suitable for users in rural area. But many now used solar water heater has no alarm device resulting water and resource wasting because of forgetting to turn off the valve after water sailing upstream. To overcome this defect, an intelligent annunciator for solar water heater installed at the end of the return pipe is presented and designed in order to remind the user. Firstly, the advantages and disadvantages of automatic and manual sailing upstream are compared concluding that manual sailing upstream is more trustiness. Then an annunciator for solar water heater is studied and ameliorated. Its principle, parameters index and functions are introduced. The annunciator uses CD4069 chip as the core circuit with very little assistant circuit. It can provide sound and light alarm at the same time. This annunciator for solar water heater water is very simple in production, low cost, the use of safe and convenient. The annunciator is applicable to all solar power products, including various types of early installation of solar power water heaters and water tanks without changing their structures. It can meet family and industrial environmental applications.

  8. Intracellular mechanisms of solar water disinfection

    Science.gov (United States)

    Castro-Alférez, María; Polo-López, María Inmaculada; Fernández-Ibáñez, Pilar

    2016-12-01

    Solar water disinfection (SODIS) is a zero-cost intervention measure to disinfect drinking water in areas of poor access to improved water sources, used by more than 6 million people in the world. The bactericidal action of solar radiation in water has been widely proven, nevertheless the causes for this remain still unclear. Scientific literature points out that generation of reactive oxygen species (ROS) inside microorganisms promoted by solar light absorption is the main reason. For the first time, this work reports on the experimental measurement of accumulated intracellular ROS in E. coli during solar irradiation. For this experimental achievement, a modified protocol based on the fluorescent probe dichlorodihydrofluorescein diacetate (DCFH-DA), widely used for oxidative stress in eukaryotic cells, has been tested and validated for E. coli. Our results demonstrate that ROS and their accumulated oxidative damages at intracellular level are key in solar water disinfection.

  9. Water solar distiller productivity enhancement using concentrating solar water heater and phase change material (PCM)

    OpenAIRE

    Miqdam T. Chaichan; Hussein A. Kazem

    2015-01-01

    This paper investigates usage of thermal energy storage extracted from concentrating solar heater for water distillation. Paraffin wax selected as a suitable phase change material, and it was used for storing thermal energy in two different insulated treasurers. The paraffin wax is receiving hot water from concentrating solar dish. This solar energy stored in PCM as latent heat energy. Solar energy stored in a day time with a large quantity, and some heat retrieved for later use. Water’s temp...

  10. Solar Neutrino Data, Solar Model Uncertainties and Neutrino Oscillations

    CERN Document Server

    Krauss, L M; White, M; Krauss, Lawrence M.; Gates, Evalyn; White, Martin

    1993-01-01

    We incorporate all existing solar neutrino flux measurements and take solar model flux uncertainties into account in deriving global fits to parameter space for the MSW and vacuum solutions of the solar neutrino problem.

  11. Solar Neutrino Data, Solar Model Uncertainties and Neutrino Oscillations

    OpenAIRE

    1992-01-01

    We incorporate all existing solar neutrino flux measurements and take solar model flux uncertainties into account in deriving global fits to parameter space for the MSW and vacuum solutions of the solar neutrino problem.

  12. Water Impacts of High Solar PV Electricity Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    This analysis provides a detailed national and regional description of the water-related impacts and constraints of high solar electricity penetration scenarios in the U.S. in 2030 and 2050. A modified version of the Regional Energy Deployment System (ReEDS) model that incorporates water resource availability and costs as a constraint in each of its 134 Balancing Area (BA) regions was utilized to explore national and regional differences in water use impacts and solar deployment locations under different solar energy cost and water availability scenarios (Macknick et al. 2015). Water resource availability and cost data are from recently completed research at Sandia National Laboratories (Tidwell et al. 2013a). Scenarios analyzed include two business-as-usual solar energy cost cases, one with and one without considering available water resources, and four solar energy cost cases that meet the SunShot cost goals (i.e., $1/watt for utility-scale PV systems), with varying levels of water availability restrictions. This analysis provides insight into the role solar energy technologies have in the broader electricity sector under scenarios of water constraints.

  13. Consumer impacts on dividends from solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    Hill, F.; Levermore, G. [University of Manchester, Manchester (United Kingdom); Lynch, H. [Centre for Alternative Technology, Machynlleth, University of East London, London (United Kingdom)

    2011-01-15

    Common domestic solar water heating system usage patterns were investigated by a survey of 55 installations. These usage patterns were modelled by simulation based on the actual occupants' use of boiler or other auxiliary heating control strategies. These strategies were not optimal, as often assumed. The effectiveness of the technology was found to be highly sensitive to the time settings used for auxiliary water heating, and the 65% of solar householders using their boilers in the mornings were found to be forgoing 75% of their potential savings. Additionally, 92% of consumers were found to be small households, whose potential savings were only 23% of those of larger households, which use more hot water. Overall the majority (at least 60%) of the systems surveyed were found to be achieving no more than 6% of their potential savings. Incorporating consideration of Legionella issues, results indicate that if solar thermal technology is to deliver its potential to CO2 reduction targets: solar householders must avoid any use of their auxiliary water heating systems before the end of the main warmth of the day, grants for solar technology should be focused on households with higher hot water demands, and particularly on those that are dependent on electricity for water heating, health and safety requirements for hot water storage must be reviewed and, if possible, required temperatures should be set at a lower level, so that carbon savings from solar water heating may be optimized.

  14. Entrance Effects in Solar Hot Water Stores

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    2003-01-01

    A theoretical and experimental analysis of water jets entering a solar storage tank is performed. CFD calculations of three inlet designs with different inlet flow rates were carried out to illustrate the varying behaviour of the thermal conditions in a solar store. The results showed the impact...

  15. Basic principles of solar water heating

    CSIR Research Space (South Africa)

    Page-Shipp, RJ

    1980-09-10

    Full Text Available This article correctly reflects the principles of Solar Water Heating as they pertain to South African conditions. However, it was written in 1980 and the global energy situation has changed considerably. Furthermore, modern commercial units...

  16. Report on Solar Water Heating Quantitative Survey

    Energy Technology Data Exchange (ETDEWEB)

    Focus Marketing Services

    1999-05-06

    This report details the results of a quantitative research study undertaken to better understand the marketplace for solar water-heating systems from the perspective of home builders, architects, and home buyers.

  17. Stratification and thermocirculation in a solar passive water wall

    Energy Technology Data Exchange (ETDEWEB)

    Russell, L.D.; Mustafa, H.; Johnson, R.

    1981-01-01

    The solar passive water wall is a passive system which collects, stores, and distributes thermal energy for the heating of buildings. An analytical model is presented in this paper for calculation of the thermocirculation through the water wall. Representative measured data are presented for the temperature stratification which occurs in a continuous water column of a water wall 2.4 meters high. 10 refs.

  18. Constant delivery temperature solar water heater - an integrated approach

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. [C.A.S. Indian Institute of Technology, New Delhi (India); Kumar, N. [D.C.E. Muzaffarpur Institute of Technology, Bihar (India)

    1997-05-01

    An integrated model of a constant delivery temperature solar water heat-cum-active regenerative distillation system has been developed. The water used for the regenerative effect in the distiller of the proposed system is subsequently fed to the basin-cum-storage tank of the still through the heat exchanger (connected to the collector). The model varies the water mass flow rate in order to maintain a constant outlet temperature. With minor modifications in the solar water heater, the extra energy stored in the water mass due to non-utilization of capacity and/or non-linear utilization of capacity can be efficiently utilized for distillation purposes. In this process, the latent heat of vaporization is used for preheating the inlet water supply to the heat exchanger. The effect of insulation on maintaining the hot water temperature and distillate output is also presented. (Author)

  19. Economic analysis of residential solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-23

    A typical residential solar water heater, and typical cost and performance information are described briefly. The monthly costs and savings of the typical system are discussed. Economic evaluations of solar water heaters are presented in increasingly complex levels of detail. Utilizing a typical system, the effective interest rate that the purchaser of a system would receive on money invested is shown for all regions of the country. The importance of numerous variables that can make a significant difference on the economics of the system is described. Methods for calculating the Payback Period for any non-typical solar water heater are described. This calculated Payback Period is then shown to be related to the effective interest rate that the puchaser of the system would receive for a typical set of economic conditions. A method is presented to calculate the effective interest rate that the solar system would provide. (MHR)

  20. Photocatalytic Water Disinfection with Solar Energy

    Energy Technology Data Exchange (ETDEWEB)

    Sichel, C.; Fernandez-Ibanez, P.; Blanco, J.; Malato, S.

    2006-07-01

    Drinking water disinfection is the final treatment phase before supplying drinking water to customers. Actually, the most widely employed disinfecting method is the chlorination. Even though it has high efficiency and long residual effects, chlorine presents the drawback of the high potential to produce chloro-organic compounds, which are hazardous. In order to find a safe method to disinfect drinking water, a number of so-called {sup n}ew technologies{sup a}re being developed by researchers from the entire world. Among these emerging technologies, the heterogeneous photocatalytic oxidation is becoming more and more important, mainly for applications in isolated and arid areas of developing countries. In the case of heterogeneous photocatalytic oxidation via TiO2, when the semiconductor is suspended or immersed in water and irradiated with near UV (?<385 nm), OH radicals are generated by the reaction of holes and electrons respectively with electron donor and acceptor molecules. The OH radical is highly toxic towards microorganisms and very reactive in the oxidation of organic substances. Therefore, a solar photocatalytic treatment can be a disinfecting method but at the same time a process to degrade organic matter. This contribution demonstrates the feasibility of using the photocatalytical processes to inactivate microorganisms present in water for potential applications in drinking water disinfection for solar systems. This work shows the main results on solar photocatalytic disinfection with solar photo-reactors, using the solar radiation and TiO2 as a photocatalyst. (Author)

  1. Water Desalination Systems Powered by Solar Energy

    Science.gov (United States)

    Barseghyan, A.

    2015-12-01

    The supply of potable water from polluted rivers, lakes, unsafe wells, etc. is a problem of high priority. One of the most effective methods to obtain low cost drinking water is desalination. Advanced water treatment system powered by Solar Energy and based on electrodialysis for water desalination and purification, is suggested. Technological and economic evaluations and the benefits of the suggested system are discussed. The Advanced Water Treatment System proposed clears water not only from different salts, but also from some infections, thus decreasing the count of diseases which are caused by the usage of non-clear water. Using Solar Energy makes the system stand alone which is convenient to use in places where power supply is problem.

  2. Potential for solar water heating in Zimbabwe

    NARCIS (Netherlands)

    Batidzirai, B.; Lysen, E.H.; van Egmond, S.; van Sark, W.G.J.H.M.

    2009-01-01

    This paper discusses the economic, social and environmental benefits from using solar water heating (SWH) in Zimbabwe. By comparing different water heating technology usage in three sectors over a 25-year period, the potential of SWH is demonstrated in alleviating energy and economic problems that e

  3. Solar-rechargeable battery based on photoelectrochemical water oxidation: Solar water battery

    Science.gov (United States)

    Kim, Gonu; Oh, Misol; Park, Yiseul

    2016-09-01

    As an alternative to the photoelectrochemical water splitting for use in the fuel cells used to generate electrical power, this study set out to develop a solar energy rechargeable battery system based on photoelectrochemical water oxidation. We refer to this design as a “solar water battery”. The solar water battery integrates a photoelectrochemical cell and battery into a single device. It uses a water oxidation reaction to simultaneously convert and store solar energy. With the solar water battery, light striking the photoelectrode causes the water to be photo-oxidized, thus charging the battery. During the discharge process, the solar water battery reduces oxygen to water with a high coulombic efficiency (>90%) and a high average output voltage (0.6 V). Because the reduction potential of oxygen is more positive [E0 (O2/H2O) = 1.23 V vs. NHE] than common catholytes (e.g., iodide, sulfur), a high discharge voltage is produced. The solar water battery also exhibits a superior storage ability, maintaining 99% of its specific discharge capacitance after 10 h of storage, without any evidence of self-discharge. The optimization of the cell design and configuration, taking the presence of oxygen in the cell into account, was critical to achieving an efficient photocharge/discharge.

  4. Solar-rechargeable battery based on photoelectrochemical water oxidation: Solar water battery.

    Science.gov (United States)

    Kim, Gonu; Oh, Misol; Park, Yiseul

    2016-09-15

    As an alternative to the photoelectrochemical water splitting for use in the fuel cells used to generate electrical power, this study set out to develop a solar energy rechargeable battery system based on photoelectrochemical water oxidation. We refer to this design as a "solar water battery". The solar water battery integrates a photoelectrochemical cell and battery into a single device. It uses a water oxidation reaction to simultaneously convert and store solar energy. With the solar water battery, light striking the photoelectrode causes the water to be photo-oxidized, thus charging the battery. During the discharge process, the solar water battery reduces oxygen to water with a high coulombic efficiency (>90%) and a high average output voltage (0.6 V). Because the reduction potential of oxygen is more positive [E(0) (O2/H2O) = 1.23 V vs. NHE] than common catholytes (e.g., iodide, sulfur), a high discharge voltage is produced. The solar water battery also exhibits a superior storage ability, maintaining 99% of its specific discharge capacitance after 10 h of storage, without any evidence of self-discharge. The optimization of the cell design and configuration, taking the presence of oxygen in the cell into account, was critical to achieving an efficient photocharge/discharge.

  5. Solar Water Splitting Using Semiconductor Photocatalyst Powders

    KAUST Repository

    Takanabe, Kazuhiro

    2015-07-01

    Solar energy conversion is essential to address the gap between energy production and increasing demand. Large scale energy generation from solar energy can only be achieved through equally large scale collection of the solar spectrum. Overall water splitting using heterogeneous photocatalysts with a single semiconductor enables the direct generation of H from photoreactors and is one of the most economical technologies for large-scale production of solar fuels. Efficient photocatalyst materials are essential to make this process feasible for future technologies. To achieve efficient photocatalysis for overall water splitting, all of the parameters involved at different time scales should be improved because the overall efficiency is obtained by the multiplication of all these fundamental efficiencies. Accumulation of knowledge ranging from solid-state physics to electrochemistry and a multidisciplinary approach to conduct various measurements are inevitable to be able to understand photocatalysis fully and to improve its efficiency.

  6. Solar wind origin of terrestrial water

    CERN Document Server

    Merkl, Hans

    2011-01-01

    The origin of the Earth water reserves during the evolution of the planet is one of the big miracles in geophysics. Common explanations are storage of water in the Earth mantle at a time when the crust had not yet formed and depositing of water by comets during the time of late heavy bombardement. Both explanations have different problems - especially when comparing with the evolution of Mars and Venus. Here we discuss the possible role of hydrogen collected from the solar wind by the early Earth magnetosphere. While the water production by solar wind capture is very small today it may have been significant during the first billion years after planetary formation because solar wind was much stronger at that time and Earth magnetospheric configuration may have been different. We estimate that the contribution of solar wind hydrogen to the Earth water reserves can be up to 10% when we assume a that the Earth dipole acted as a collector and early solar wind was 1000 times stronger than today. We can not even exc...

  7. Low Cost Solar Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    William Bostic

    2005-12-16

    This project was directed by NREL to pursue development of an all polymer solar thermal collector. The proposed design utilized a dual sheet thermoform process to coincidentally form the absorber as well as the containment structure to support the glazing. It utilized ventilation to overcome stagnation degradation of the polymer materials.

  8. The Character of the Solar Wind, Surface Interactions, and Water

    Science.gov (United States)

    Farrell, William M.

    2011-01-01

    We discuss the key characteristics of the proton-rich solar wind and describe how it may interact with the lunar surface. We suggest that solar wind can be both a source and loss of water/OH related volatiles, and review models showing both possibilities. Energy from the Sun in the form of radiation and solar wind plasma are in constant interaction with the lunar surface. As such, there is a solar-lunar energy connection, where solar energy and matter are continually bombarding the lunar surface, acting at the largest scale to erode the surface at 0.2 Angstroms per year via ion sputtering [1]. Figure 1 illustrates this dynamically Sun-Moon system.

  9. Engineering solutions for polymer composites solar water heaters production

    Science.gov (United States)

    Frid, S. E.; Arsatov, A. V.; Oshchepkov, M. Yu.

    2016-06-01

    Analysis of engineering solutions aimed at a considerable decrease of solar water heaters cost via the use of polymer composites in heaters construction and solar collector and heat storage integration into a single device representing an integrated unit results are considered. Possibilities of creating solar water heaters of only three components and changing welding, soldering, mechanical treatment, and assembly of a complicate construction for large components molding of polymer composites and their gluing are demonstrated. Materials of unit components and engineering solutions for their manufacturing are analyzed with consideration for construction requirements of solar water heaters. Optimal materials are fiber glass and carbon-filled plastics based on hot-cure thermosets, and an optimal molding technology is hot molding. It is necessary to manufacture the absorbing panel as corrugated and to use a special paint as its selective coating. Parameters of the unit have been optimized by calculation. Developed two-dimensional numerical model of the unit demonstrates good agreement with the experiment. Optimal ratio of daily load to receiving surface area of a solar water heater operating on a clear summer day in the midland of Russia is 130‒150 L/m2. Storage tank volume and load schedule have a slight effect on solar water heater output. A thermal insulation layer of 35‒40 mm is sufficient to provide an efficient thermal insulation of the back and side walls. An experimental model layout representing a solar water heater prototype of a prime cost of 70‒90/(m2 receiving surface) has been developed for a manufacturing volume of no less than 5000 pieces per year.

  10. Solar models and solar neutrino oscillations

    OpenAIRE

    2004-01-01

    We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.

  11. Solar system for domestic hot water and space heating

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W. [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

    1997-12-31

    The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

  12. Ground water distillation by basin type solar still for different basin water depth under the climatic condition of Rewa

    Directory of Open Access Journals (Sweden)

    AbhayAgrawal

    2015-12-01

    Full Text Available Adequate quality and reliability of drinking water supply is a fundamental need. Without potable water or drinking water (less than about 500 ppm of salt human life is not possible. Only 1% of Earth's water is in a fresh, liquid state, and nearly all of this is polluted by both diseases and toxic chemicals. For this reason, purification of water supplies is extremely important. Keeping these things in mind, we have devised a model which will convert the saline ground water into pure and potable water using the renewable source of energy (i.e. solar energy. Solar energy is an abundant, never lasting, and available on site and pollution free energy.Solar Energy is freely available and can be used as a very cheap option to convert saline ground Water through Solar Distillation, by using Solar Stills. The conventional single basin and single slop Passive Solar Still can be used to purify water but the main problem is that the per square meter distillate output is less. So it is need to modify the design of solar still for high output of solar distillate Solar still is easy to construct, can be done by local people from locally available materials, simple in operation by unskilled Personnel, no hard maintenance requirements and almost no operation cost. Simplest basin type models of solar still in earlier days, researchers have progressed a lot to increase its efficiency. Suitable modification of solar still can produce high output using minimum areas of land and even in cloudy days. Experimental study is done at Rewa M.P. on two different basin water depth solar stills. Low water depth solar water still is produced more distillate than high water depth still by the experiment.

  13. Energy Primer: Solar, Water, Wind, and Biofuels.

    Science.gov (United States)

    Portola Inst., Inc., Menlo Park, CA.

    This is a comprehensive, fairly technical book about renewable forms of energy--solar, water, wind, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…

  14. Energy Primer: Solar, Water, Wind, and Biofuels.

    Science.gov (United States)

    Portola Inst., Inc., Menlo Park, CA.

    This is a comprehensive, fairly technical book about renewable forms of energy--solar, water, wind, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…

  15. Solar models: An historical overview

    Energy Technology Data Exchange (ETDEWEB)

    Bahcall, John N. E-mail: jnb@ias.edu

    2003-04-01

    I will summarize in four slides the 40 years of development of the standard solar model that is used to predict solar neutrino fluxes and then describe the current uncertainties in the predictions. I will dispel the misconception that the p-p neutrino flux is determined by the solar luminosity and present a related formula that gives, in terms of the p-p and {sup 7}Be neutrino fluxes, the ratio of the rates of the two primary ways of terminating the p-p fusion chain. I will also attempt to explain why it took so long, about three and a half decades, to reach a consensus view that new physics is being learned from solar neutrino experiments. Finally, I close with a personal confession.

  16. Solar Models An Historical Overview

    CERN Document Server

    Bahcall, J N

    2002-01-01

    I summarize in four slides the 40 years of development of the standard solar model that is used to predict solar neutrino fluxes and then describe the current uncertainties in the predictions. I next dispel the misconception that the p-p neutrino flux is determined by the solar luminosity and present a related formula that gives, in terms of the p-p and 7Be neutrino fluxes, the ratio of the rates of the two primary ways of terminating the p-p fusion chain. I will also attempt to explain why it took so long, about three and a half decades, to reach a consensus view that new physics is being learned from solar neutrino experiments. Finally, I close with a personal confession.

  17. Solar Water Heating with Low-Cost Plastic Systems (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2012-01-01

    Newly developed solar water heating technology can help Federal agencies cost effectively meet the EISA requirements for solar water heating in new construction and major renovations. This document provides design considerations, application, economics, and maintenance information and resources.

  18. Numerical study of a water distillation system using solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Zarzoum, K.; Zhani, K. [Sfax University, (Turkey); Bacha, H. Ben [Prince Sattam Bin Abdulaziz University, Alkharj (Saudi Arabia)

    2016-02-15

    This paper tackles an optimization approach in order to boost the fresh water production of a new design of a solar still which is located at Sfax engineering national school in Tunisia. This optimization approach is based upon the above mentioned design's improvement by coupling the conventional solar still into at a condenser, solar air and water collector and humidifier. This new concept of a distiller solar still using humidification- dehumidification processes (HD) is exploited for the desalination purpose. As a result of this work, the humidification- dehumidification processes have an essential effect in improving the solar still performance. Performance has been predicted theoretically in terms of water and inner glass cover temperatures, the inlet temperature of air and water of the new concept of distiller on water condensation rate and fresh water production. A general model based on heat and mass transfers in each component of the unit has been developed in steady dynamic regime. The developed model is used, simulating the HD system, to investigate the influence of the meteorological and operating parameters on the system productivity. The obtained set of ordinary differential equations has been converted to a set of algebraic system of equations by the functional approximation method of orthogonal collocation. The developed model is used to simulate the HD system in order to investigate the steady state behavior of each component of the unit and the entire system exposed to a variation of the entrance parameters and meteorological conditions. The obtained results were compared with those of other studies and the comparison gives a good validity of the present results.

  19. Artificial photosynthesis for solar water-splitting

    Science.gov (United States)

    Tachibana, Yasuhiro; Vayssieres, Lionel; Durrant, James R.

    2012-08-01

    Hydrogen generated from solar-driven water-splitting has the potential to be a clean, sustainable and abundant energy source. Inspired by natural photosynthesis, artificial solar water-splitting devices are now being designed and tested. Recent developments based on molecular and/or nanostructure designs have led to advances in our understanding of light-induced charge separation and subsequent catalytic water oxidation and reduction reactions. Here we review some of the recent progress towards developing artificial photosynthetic devices, together with their analogies to biological photosynthesis, including technologies that focus on the development of visible-light active hetero-nanostructures and require an understanding of the underlying interfacial carrier dynamics. Finally, we propose a vision for a future sustainable hydrogen fuel community based on artificial photosynthesis.

  20. AWSWAH - the heat pipe solar water heater

    Energy Technology Data Exchange (ETDEWEB)

    Akyurt, M.

    1986-01-01

    An all weather heat pipe solar water heater (AWSWAH) comprising a collector of 4 m/sup 2/ (43 ft/sup 2/) and a low profile water tank of 160 liters (42 gal.) was developed. A single heat pipe consisting of 30 risers and two manifolds in the evaporator and a spiral condenser was incorporated into the AWSWAH. Condensate metering was done by synthetic fiber wicks. The AWSWAH was tested alongside two conventional solar water heaters of identical dimensions, an open loop system and a closed loop system. It was found that the AWSWAH was an average of 50% more effective than the open system in the temperature range 30-90 /sup 0/C (86-194 /sup 0/F). The closed loop system was the least efficient of the three systems.

  1. Hourly use profiles for solar domestic hot water heaters in the National Solar Data Network

    Science.gov (United States)

    Barvir, E. J.; Doak, L. G.; Waterman, R. E.; Gervasio, C.

    Daily hot water rates of consumption and the Hourly Profiles of Daily Hot Water Consumption for single and multiple family dwellings are provided in this paper. These new statistics obtained from the National Solar Data Network (NSDN) are significantly different from the statistics currently being used in TRNSYS, SOLCOST and F-Chart. The NSDN statistics suggest that both the daily demand and hourly use profiles used in performance models should be revised.

  2. Installation package for a sunspot cascade solar water heating system

    Science.gov (United States)

    1980-01-01

    Solar water heating systems installed at Tempe, Arizona and San Diego, California are described. The systems consist of the following: collector, collector-tank water loop, solar tank, conventional tank, and controls. General guidelines which may be utilized in development of detailed installation plans and specifications are provided along with instruction on operation, maintenance, and installation of solar hot water systems.

  3. Numerical Simulation of a Solar Domestic Hot Water System

    Science.gov (United States)

    Mongibello, L.; Bianco, N.; Di Somma, M.; Graditi, G.; Naso, V.

    2014-11-01

    An innovative transient numerical model is presented for the simulation of a solar Domestic Hot Water (DHW) system. The solar collectors have been simulated by using a zerodimensional analytical model. The temperature distributions in the heat transfer fluid and in the water inside the tank have been evaluated by one-dimensional models. The reversion elimination algorithm has been used to include the effects of natural convection among the water layers at different heights in the tank on the thermal stratification. A finite difference implicit scheme has been implemented to solve the energy conservation equation in the coil heat exchanger, and the energy conservation equation in the tank has been solved by using the finite difference Euler implicit scheme. Energy conservation equations for the solar DHW components models have been coupled by means of a home-made implicit algorithm. Results of the simulation performed using as input data the experimental values of the ambient temperature and the solar irradiance in a summer day are presented and discussed.

  4. Solar detoxification of waste waters

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, J. M.

    2000-07-01

    Heterogeneous photocatalysis is a discipline which includes a large variety of reactions: mild or total oxidations, dehydrogenation, hydrogen transfer. oxygen-18 and deuterium isotopic exchange, metal deposition, water detoxification, gaseous pollutant removal, etc. In line with the latter point, it can be considered as one of the new Advanced Oxidation Technologies (AOT) for air and water purification treatment. Several books and reviews have been recently devoted to this problem (1-6). A recent review has reported more than 1200 references on the subject (7). Heterogeneous photocatalysis can be carried out in various media: gas phase, pure organic liquid phases or aqueous solutions. As for classical heterogeneous catalysis, the overall process can be decomposed into five independent steps: 1. Transfer of the reactants in the fluid to the surface. 2. Adsorption of a least one of the reactants. 3. Reaction in the adsorbed phase 4. Desorption of the product (s) 5. Removal of the products from the interface region. (Author) 11 refs.

  5. Solar Detoxification of Waste Waters

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, J.M.

    2002-07-01

    Heterogeneous photocatalysis is a discipline which includes a large variety of reactions: mild or total oxidations, dehydrogenation, hydrogen transfer, oxygen-18 and deuterium isotopic exchange, metal deposition, water detoxification, gaseous pollutant removal, etc. In line with the latter point, it can be considered as one of the new. Advanced Oxidation Technologies (AOT) for air and water purification treatment. Several books and reviews have been recently devoted to this problem (1-6). A recent review has reported more than 1200 references on the subject. Heterogeneous photocatalysis can be carried out in various media: gas phase, pure organic liquid phases or aqueous solutions. As for classical heterogeneous catalysis, the overall process can be decomposed into five independent steps: 1. Transfer of the reactants in the fluid phase to the surface 2. Adsorption of a least one of the reactants 3. Reaction in the adsorbed phase 4. Desorption of the products 5. Removal of the products from the interface region. (Author)

  6. Continuous-flow solar UVB disinfection reactor for drinking water.

    Science.gov (United States)

    Mbonimpa, Eric Gentil; Vadheim, Bryan; Blatchley, Ernest R

    2012-05-01

    Access to safe, reliable sources of drinking water is a long-standing problem among people in developing countries. Sustainable solutions to these problems often involve point-of-use or community-scale water treatment systems that rely on locally-available resources and expertise. This philosophy was used in the development of a continuous-flow, solar UVB disinfection system. Numerical modeling of solar UVB spectral irradiance was used to define temporal variations in spectral irradiance at several geographically-distinct locations. The results of these simulations indicated that a solar UVB system would benefit from incorporation of a device to amplify ambient UVB fluence rate. A compound parabolic collector (CPC) was selected for this purpose. Design of the CPC was based on numerical simulations that accounted for the shape of the collector and reflectance. Based on these simulations, a prototype CPC was constructed using materials that would be available and inexpensive in many developing countries. A UVB-transparent pipe was positioned in the focal area of the CPC; water was pumped through the pipe to allow exposure of waterborne microbes to germicidal solar UVB radiation. The system was demonstrated to be effective for inactivation of Escherichia coli, and DNA-weighted UV dose was shown to govern reactor performance. The design of the reactor is expected to scale linearly, and improvements in process performance (relative to results from the prototype) can be expected by use of larger CPC geometry, inclusion of better reflective materials, and application in areas with greater ambient solar UV spectral irradiance than the location of the prototype tests. The system is expected to have application for water treatment among communities in (developing) countries in near-equatorial and tropical locations. It may also have application for disaster relief or military field operations, as well as in water treatment in areas of developed countries that receive

  7. Water decontamination by solar photocatalysis. Descontaminacion de aguas residuales mediante fotocatalisis solar

    Energy Technology Data Exchange (ETDEWEB)

    Blanco Galvez, J.; Malato Rodriguez, S.

    1993-01-01

    A solar photocatalytic system is being developed at the Plataforma Solar de Almeria to destroy organic contaminants in water. Test with common water contaminants were conducted at the Solar Detoxification Loop with real sunlight and large quantities of water flowing through glass tubes were the solar UV light is concentrated. Experiments at this scale provide verification of laboratory studies and allow the design and operation of real preindustrial detoxification systems. (Author)

  8. Solar geoengineering, atmospheric water vapor transport, and land plants

    Science.gov (United States)

    Caldeira, Ken; Cao, Long

    2015-04-01

    This work, using the GeoMIP database supplemented by additional simulations, discusses how solar geoengineering, as projected by the climate models, affects temperature and the hydrological cycle, and how this in turn is related to projected changes in net primary productivity (NPP). Solar geoengineering simulations typically exhibit reduced precipitation. Solar geoengineering reduces precipitation because solar geoengineering reduces evaporation. Evaporation precedes precipitation, and, globally, evaporation equals precipitation. CO2 tends to reduce evaporation through two main mechanisms: (1) CO2 tends to stabilize the atmosphere especially over the ocean, leading to a moister atmospheric boundary layer over the ocean. This moistening of the boundary layer suppresses evaporation. (2) CO2 tends to diminish evapotranspiration, at least in most land-surface models, because higher atmospheric CO2 concentrations allow leaves to close their stomata and avoid water loss. In most high-CO2 simulations, these effects of CO2 which tend to suppress evaporation are masked by the tendency of CO2-warming effect to increase evaporation. In a geoengineering simulation, with the warming effect of CO2 largely offset by the solar geoengineering, the evaporation suppressing characteristics of CO2 are no longer masked and are clearly exhibited. Decreased precipitation in solar geoengineering simulations is a bit like ocean acidification - an effect of high CO2 concentrations that is not offset by solar geoengineering. Locally, precipitation ultimately either evaporates (much of that through the leaves of plants) or runs off through groundwater to streams and rivers. On long time scales, runoff equals precipitation minus evaporation, and thus, water runoff generated at a location is equal to the net atmospheric transport of water to that location. Runoff typically occurs where there is substantial soil moisture, at least seasonally. Locations where there is enough water to maintain

  9. Water Splitting with Series-Connected Polymer Solar Cells.

    Science.gov (United States)

    Esiner, Serkan; van Eersel, Harm; van Pruissen, Gijs W P; Turbiez, Mathieu; Wienk, Martijn M; Janssen, René A J

    2016-10-12

    We investigate light-driven electrochemical water splitting with series-connected polymer solar cells using a combined experimental and modeling approach. The expected maximum solar-to-hydrogen conversion efficiency (ηSTH) for light-driven water splitting is modeled for two, three, and four series-connected polymer solar cells. In the modeling, we assume an electrochemical water splitting potential of 1.50 V and a polymer solar cell for which the external quantum efficiency and fill factor are both 0.65. The minimum photon energy loss (Eloss), defined as the energy difference between the optical band gap (Eg) and the open-circuit voltage (Voc), is set to 0.8 eV, which we consider a realistic value for polymer solar cells. Within these approximations, two series-connected single junction cells with Eg = 1.73 eV or three series-connected cells with Eg = 1.44 eV are both expected to give an ηSTH of 6.9%. For four series-connected cells, the maximum ηSTH is slightly less at 6.2% at an optimal Eg = 1.33 eV. Water splitting was performed with series-connected polymer solar cells using polymers with different band gaps. PTPTIBDT-OD (Eg = 1.89 eV), PTB7-Th (Eg = 1.56 eV), and PDPP5T-2 (Eg = 1.44 eV) were blended with [70]PCBM as absorber layer for two, three, and four series-connected configurations, respectively, and provide ηSTH values of 4.1, 6.1, and 4.9% when using a retroreflective foil on top of the cell to enhance light absorption. The reasons for deviations with experiments are analyzed and found to be due to differences in Eg and Eloss. Light-driven electrochemical water splitting was also modeled for multijunction polymer solar cells with vertically stacked photoactive layers. Under identical assumptions, an ηSTH of 10.0% is predicted for multijunction cells.

  10. Design of multifamily solar domestic hot water systems using recirculating distribution

    Energy Technology Data Exchange (ETDEWEB)

    Wedekind, D.R.

    1982-01-01

    This paper describes a study designed to quantify the effect of daily domestic hot water loads and system design on the performance of solar domestic hot water systems employing a recirculating distribution system. A solar domestic hot water system judged representative of the systems funded by the HUD Solar Demonstration Program, along with a modification to this system, was modeled using the TRNSYS simulation computer program. Results of simulations over a representative climatic period show that daily domestic hot water usage significantly affects solar system performance. Notable improvement in system performance can be obtained by the use of a recirculation return to solar storage system configuration within a specific range of daily domestic hot water loads. An optimum system was developed from parametric variations of system design and modeled on an annual basis. Comparison is made to modeled system performance of the original design.

  11. Water solar distiller productivity enhancement using concentrating solar water heater and phase change material (PCM

    Directory of Open Access Journals (Sweden)

    Miqdam T. Chaichan

    2015-03-01

    Full Text Available This paper investigates usage of thermal energy storage extracted from concentrating solar heater for water distillation. Paraffin wax selected as a suitable phase change material, and it was used for storing thermal energy in two different insulated treasurers. The paraffin wax is receiving hot water from concentrating solar dish. This solar energy stored in PCM as latent heat energy. Solar energy stored in a day time with a large quantity, and some heat retrieved for later use. Water’s temperature measured in a definite interval of time. Four cases were studied: using water as storage material with and without solar tracker. Also, PCM was as thermal storage material with and without solar tracker.The system working time was increased to about 5 h with sun tracker by concentrating dish and adding PCM to the system. The system concentrating efficiency, heating efficiency, and system productivity, has increased by about 64.07%, 112.87%, and 307.54%, respectively. The system working time increased to 3 h when PCM added without sun tracker. Also, the system concentrating efficiency increased by about 50.47%, and the system heating efficiency increased by about 41.63%. Moreover, the system productivity increased by about 180%.

  12. HOT WATER COMFORT TEST PROCEDURE FOR SOLAR COMBISYSTEMS: PROPOSAL

    DEFF Research Database (Denmark)

    Furbo, Simon

    1999-01-01

    A proposal for a test procedure for hot water comfort for solar heating systems for combined space heating and domestic hot water supply was worked out.......A proposal for a test procedure for hot water comfort for solar heating systems for combined space heating and domestic hot water supply was worked out....

  13. Solar water heating system for a lunar base

    Science.gov (United States)

    Somers, Richard E.; Haynes, R. Daniel

    1992-01-01

    An investigation of the feasibility of using a solar water heater for a lunar base is described. During the investigation, computer codes were developed to model the lunar base configuration, lunar orbit, and heating systems. Numerous collector geometries, orientation variations, and system options were identified and analyzed. The results indicate that the recommended solar water heater could provide 88 percent of the design load and would not require changes in the overall lunar base design. The system would give a 'safe-haven' water heating capability and use only 7 percent to 10 percent as much electricity as an electric heating system. As a result, a fixed position photovoltaic array can be reduced by 21 sq m.

  14. Review of feasible solar energy applications to water processes

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, J.; Malato, S.; Fernandez-Ibanez, P.; Alarcon, D.; Gernjak, W.; Maldonado, M.I. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Plataforma Solar de Almeria (CIEMAT-PSA), Tabernas (Almeria) (Spain)

    2009-08-15

    In the context of an upcoming energy crisis due to the decline of the Oil Era, water problems are expected to substantially worsen. And vice versa, due to the close relationship between water and energy issues, water problems are also expected to contribute to increased energy problems. Furthermore, environmental considerations, such as global warming, will surely add significant pressure. In this scenario, renewable energies are rapidly increasing their contribution to the global mix, with solar energy clearly having the greatest potential, and in view of the worldwide coincidence that where there is water stress and/or scarcity, there are also good solar radiation levels, the conclusion seems clear suitable technologies must be developed to permit the use of solar energy to simultaneously help solve energy and water problems. The main solar energy applications for water processes presented in this paper are: (1) solar desalination; (2) solar detoxification and; (3) solar disinfection. (author)

  15. Purification Of Water From Nsukka Water Pond Using Solar Still.

    Directory of Open Access Journals (Sweden)

    Ugwuoke E.C

    2015-08-01

    Full Text Available Abstract This work presents the analysis of a solar water distillation system. There is important need for good drinking water in the world today due to harmful effect of water borne diseases. Most water from rivers ponds seas are either salty or brackish and require purification before drinking. The water used in this work is collected from pond at Nsukka Urban and the experiment was performed at University of Nigeria Nsukka. Twenty litres of water was used for the experiment and 4 litres was obtained as the maximum volume after 10 days .The average temperature recorded during the experiment was 29C. The chemical and physical properties of the distillate correspond to world Health Organization Standard.

  16. Models of Solar Irradiance Variations: Current Status

    Indian Academy of Sciences (India)

    Natalie A. Krivova; Sami K. Solanki

    2008-03-01

    Regular monitoring of solar irradiance has been carried out since 1978 to show that solar total and spectral irradiance varies at different time scales. Whereas variations on time scales of minutes to hours are due to solar oscillations and granulation, variations on longer time scales are driven by the evolution of the solar surface magnetic field. Here the most recent advances in modelling of solar irradiance variations on time scales longer than a day are briefly reviewed.

  17. Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

    OpenAIRE

    Xu Ji; Ming Li; Weidong Lin; Tufeng Zheng; Yunfeng Wang

    2015-01-01

    The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to ...

  18. Modeling solar radiation at the Earth's surface recent advances

    CERN Document Server

    Badescu, Viorel

    2008-01-01

    Solar radiation data is important for a wide range of applications, e.g. in engineering, agriculture, health sector, and in many fields of the natural sciences. A few examples showing the diversity of applications may include: architecture and building design e.g. air conditioning and cooling systems; solar heating system design and use; solar power generation; weather and climate prediction models; evaporation and irrigation; calculation of water requirements for crops; monitoring plant growth and disease control; skin cancer research. Solar radiation data must be provided in a variety of f

  19. Solar Model Parameters and Direct Measurements of Solar Neutrino Fluxes

    CERN Document Server

    Bandyopadhyay, A; Goswami, S; Petcov, S T; Bandyopadhyay, Abhijit; Choubey, Sandhya; Goswami, Srubabati

    2006-01-01

    We explore a novel possibility of determining the solar model parameters, which serve as input in the calculations of the solar neutrino fluxes, by exploiting the data from direct measurements of the fluxes. More specifically, we use the rather precise value of the $^8B$ neutrino flux, $\\phi_B$ obtained from the global analysis of the solar neutrino and KamLAND data, to derive constraints on each of the solar model parameters on which $\\phi_B$ depends. We also use more precise values of $^7Be$ and $pp$ fluxes as can be obtained from future prospective data and discuss whether such measurements can help in reducing the uncertainties of one or more input parameters of the Standard Solar Model.

  20. Solar hot water system installed at Days Inn Motel, Dallas, Texas (Valley View)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    The solar hot water system installed in the Days Inns of America, Inc., Days Inn Motel (120 rooms), I-35/2276 Valley View Lane, Dallas, Texas is described. The solar system was designed by ILI Incorporated to provide 65 percent of the total domestic hot water (DHW) demand. The Solar Energy Products, model CU-30WW liquid (water) flat plate collector (1000 square feet) system automatically drains into the 1000 gallon steel storage tank when the solar pump is not running. This system is one of eleven systems planned. Heat is transferred from the DHW tanks through a shell and tube heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up standby losses. All pumps are controlled by differential temperature controllers. The operation of this system was begun March 11, 1980. The solar components were partly funded ($15,000 of 30,000 cost) by a Department of Energy grant.

  1. Model development and validation of a solar cooling plant

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano, Darine; Garcia-Gabin, Winston [Escuela de Ingenieria Electrica, Facultad de Ingenieria, Universidad de Los Andes, La Hechicera, Merida 5101 (Venezuela); Bordons, Carlos; Camacho, Eduardo F. [Departamento de Ingenieria de Sistemas y Automatica, Escuela Superior de Ingenieros, Universidad de Sevilla, Camino de Los Descubrimientos s/n, Sevilla 41092 (Spain)

    2008-03-15

    This paper describes the dynamic model of a solar cooling plant that has been built for demonstration purposes using market-available technology and has been successfully operational since 2001. The plant uses hot water coming from a field of solar flat collectors which feed a single-effect absorption chiller of 35 kW nominal cooling capacity. The work includes model development based on first principles and model validation with a set of experiments carried out on the real plant. The simulation model has been done in a modular way, and can be adapted to other solar cooling-plants since the main modules (solar field, absorption machine, accumulators and auxiliary heater) can be easily replaced. This simulator is a powerful tool for solar cooling systems both during the design phase, when it can be used for component selection, and also for the development and testing of control strategies. (author)

  2. Water delivery in the Early Solar System

    CERN Document Server

    Dvorak, Rudolf; Süli, Áron; Sándor, Zsolt; Galiazzo, Mattia; Pilat-Lohinger, Elke

    2015-01-01

    As part of the national scientific network 'Pathways to Habitable Worlds' the delivery of water onto terrestrial planets is a key question since water is essential for the development of life as we know it. After summarizing the state of the art we show some first results of the transport of water in the early Solar System for scattered main belt objects. Hereby we investigate the questions whether planetesimals and planetesimal fragments which have gained considerable inclination due to the strong dynamical interactions in the main belt region around 2 AU can be efficient water transporting vessels. The Hungaria asteroid group is the best example that such scenarios are realistic. Assuming that the gas giants and the terrestrial planets are already formed, we monitor the collisions of scattered small bodies containing water (in the order of a few percent) with the terrestrial planets. Thus we are able to give a first estimate concerning the respective contribution of such bodies to the actual water content i...

  3. Modeling and verification of hemispherical solar still using ANSYS CFD

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, Hitesh N. [KSV University, Gujarat Power Engineering and Research Institute, Mehsana (India); Shah, P.K. [Silver Oak College of Engineering and Technology, Ahmedabad, Gujarat (India)

    2013-07-01

    In every efficient solar still design, water temperature, vapor temperature and distillate output, and difference between water temperature and inner glass cover temperatures are very important. Here, two dimensional three phase model of hemispherical solar still is made for evaporation as well as condensation process in ANSYS CFD. Simulation results like water temperature, vapor temperature, distillate output compared with actual experimental results of climate conditions of Mehsana (latitude of 23° 59’ and longitude of 72° 38) of hemispherical solar still. Water temperature and distillate output were good agreement with actual experimental results. Study shows that ANSYS-CFD is very powerful as well as efficient tool for design, comparison purpose of hemispherical solar still.

  4. Installation package for a solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    Development and installation of two commercial solar heating and hot water systems are reported. The systems consist of the following subsystems: collector, storage, transport, hot water, auxiliary energy and controls. General guidelines are provided which may be utilized in development of detailed installation plans and specifications. In addition, operation, maintenance and repair of a solar heating and hot water system instructions are included.

  5. Solar radiation and water vapor pressure to forecast chickenpox epidemics.

    Science.gov (United States)

    Hervás, D; Hervás-Masip, J; Nicolau, A; Reina, J; Hervás, J A

    2015-03-01

    The clear seasonality of varicella infections in temperate regions suggests the influence of meteorologic conditions. However, there are very few data on this association. The aim of this study was to determine the seasonal pattern of varicella infections on the Mediterranean island of Mallorca (Spain), and its association with meteorologic conditions and schooling. Data on the number of cases of varicella were obtained from the Network of Epidemiologic Surveillance, which is composed of primary care physicians who notify varicella cases on a compulsory basis. From 1995 to 2012, varicella cases were correlated to temperature, humidity, rainfall, water vapor pressure, atmospheric pressure, wind speed, and solar radiation using regression and time-series models. The influence of schooling was also analyzed. A total of 68,379 cases of varicella were notified during the study period. Cases occurred all year round, with a peak incidence in June. Varicella cases increased with the decrease in water vapor pressure and/or the increase of solar radiation, 3 and 4 weeks prior to reporting, respectively. An inverse association was also observed between varicella cases and school holidays. Using these variables, the best fitting autoregressive moving average with exogenous variables (ARMAX) model could predict 95 % of varicella cases. In conclusion, varicella in our region had a clear seasonality, which was mainly determined by solar radiation and water vapor pressure.

  6. Solar thermal water heating : an application for Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Jackman, T. [Simple Solar Heating Ltd., Okotoks, AB (Canada); Lonseth, R.; Lonseth, A.; Jagoda, K. [Mount Royal College, Calgary, AB (Canada)

    2009-07-01

    The use of renewable energy resources is an essential feature in curtailing greenhouse gas (GHG) emissions. This paper discussed solar thermal water heating applications for Alberta. In particular, it presented a case study of the successful commercial application of solar thermal water heating systems in households in the city of Calgary. The system used solar-thermal collectors with heat pipes mounted inside vacuum sealed glass cylinders. The devices collected heat and transferred it to a copper manifold even in extreme winter temperatures. The system included a solar storage tank integrated into a domestic hot water system. The solar fluid circulated through the solar tank. Fresh cold water entered the solar tank when hot water was used in the house in order to be preheated before entering the original water heating tank. A 25 watt pump was mounted in the closed solar loop to circulate the solar heat transfer fluid. An economic analysis demonstrated that a 2-panel system saved the equivalent of 2.4 acres of carbon-absorbing forest and had the same benefit as purchasing a hybrid car. The payback period for the system was 4 years. It was concluded that solar thermal systems are the best renewable energy method for domestic water heating in Calgary. 10 refs., 2 tabs., 5 figs.

  7. Hydrogen Generation by Solar Photolysis of Water

    Science.gov (United States)

    Graetzel, Michael

    2004-03-01

    Prospects of near term fuel cell applications for transportation and communication have stimulated recently great interest in systems that can generate hydrogen through water cleavage by sunlight. A device that appears very promising to accomplish this goal is a tandem cell based on two superimposed photoactive layers [1]. The top layer consists of nanocrystalline oxide film absorbing the blue part of the solar spectrum and producing oxygen from water under light excitation. This is placed directly on top of a dye-sensitized nanocrystalline TiO2 film (DSC) capturing the green and red part of the solar spectrum. The voltage generated by this second photosystem enables hydrogen production to proceed without application of an external electric bias. The overall reaction corresponds to the splitting of water into hydrogen and oxygen by visible light. The maximum conversion efficiency achieved so far with these systems is about 6-7 electrode a nanocrystalline WO3 film. The use of nanoparticles for the top layer has several great advantages. They are translucent avoiding losses by light scattering and their small size is within the minority carrier diffusion length, allowing the valence band hole reaction with water at the particle surface to proceed with high efficiency. Recent work has focused on replacing the WO3 by semiconductor oxide absorbing a larger fraction of visible light than tungsten trioxide, e.g. Fe2O3.The principles and current state of this research will be briefly reviewed. Literature 1. M. Graetzel, "Photoelectrochemical Cells" Nature, 414, 332-344 (2001)

  8. Implications of solar wind measurements for solar models and composition

    Science.gov (United States)

    Serenelli, Aldo; Scott, Pat; Villante, Francesco L.; Vincent, Aaron C.; Asplund, Martin; Basu, Sarbani; Grevesse, Nicolas; Peña-Garay, Carlos

    2016-11-01

    We critically examine recent claims of a high solar metallicity by von Steiger & Zurbuchen (2016, vSZ16) based on in situ measurements of the solar wind, rather than the standard spectroscopically inferred abundances (Asplund et al. 2009, hereafter AGSS09). We test the claim by Vagnozzi et al. (2016) that a composition based on the solar wind enables one to construct a standard solar model in agreement with helioseismological observations and thus solve the decades-old solar modelling problem. We show that, although some helioseismological observables are improved compared to models computed with spectroscopic abundances, most are in fact worse. The high abundance of refractory elements leads to an overproduction of neutrinos, with a predicted 8B flux that is nearly twice its observed value, and 7Be and CNO fluxes that are experimentally ruled out at high confidence. A combined likelihood analysis shows that models using the vSZ16 abundances are worse than AGSS09 despite a higher metallicity. We also present astrophysical and spectroscopic arguments showing the vSZ16 composition to be an implausible representation of the solar interior, identifying the first ionization potential effect in the outer solar atmosphere and wind as the likely culprit.

  9. Solar photocatalytic degradation of water and air pollutants: challenges and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Romero, M.; Blanco, J.; Sanchez, B.; Vidal, A.; Malato, S.; Cardona, A.I.; Garcia, E. [CIEMAT, Madrid (Spain)

    1999-06-01

    Solar photocatalytic oxidation processes (PCO) for degradation of water and air pollutants have recently received increasing attention. Some field-scale experiments have demonstrated the feasibility of using a semiconductor (TiO{sub 2}) in solar collectors and concentrators to completely mineralize organic contaminants in water and air. Although successful pre-industrial solar tests have been carried out, there are still discrepancies and doubt concerning process fundamentals such as the roles of active components, appropriate modelling of reaction kinetics or quantification of photoefficiency. Challenges to development are catalyst deactivation, slow kinetics, low photoefficiency and unpredictable mechanisms. The development of specific non-concentrating collectors for detoxification and the use of additives such as peroxydisulfate have made competitive use of solar PCO possible. The challenges and perspectives of solar driven PCO as illustrated in the literature and our own results in large solar field loops at the Plataforma Solar de Almeria and CIEMAT laboratories are described. (author)

  10. Development of Solar Drying Model for Selected Cambodian Fish Species

    Directory of Open Access Journals (Sweden)

    Anna Hubackova

    2014-01-01

    Full Text Available A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R2, chi-square (χ2 test, and root-mean-square error (RMSE, the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing.

  11. Development of solar drying model for selected Cambodian fish species.

    Science.gov (United States)

    Hubackova, Anna; Kucerova, Iva; Chrun, Rithy; Chaloupkova, Petra; Banout, Jan

    2014-01-01

    A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6 °C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg · h(-1). Based on coefficient of determination (R(2)), chi-square (χ(2)) test, and root-mean-square error (RMSE), the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing.

  12. Thermo-economic performance of inclined solar water distillation systems

    Directory of Open Access Journals (Sweden)

    Agboola Phillips O.

    2015-01-01

    Full Text Available This study investigates the thermo-economic performance of different configurations of inclined solar water desalination for parameters such as daily production, efficiency, system cost and distilled water production cost. The four different configurations considered for this study are as follows; 1. Inclined solar water distillation with bare absorber plate (IISWD with daily production of 5.46 kg/m2 day and daily efficiency of 48.3%. 2. Inclined solar water distillation with wick on absorber plate (IISWDW with daily production of 6.41kg/m2 day and daily efficiency 50.3%. 3. Inclined solar water distillation with wire mesh on absorber plate (IISWDWM with daily production n of 3.03 kg/m2 day and daily efficiency 32.6%. 4. Inclined solar water distillation with bare absorber plate (ISWD. (Control System with daily production of 3.25 kg/m2 day and daily efficiency of 40.1%. The systems potable water cost price ranges from 0.03 $/L for IISWDW to 0.06$/L for IISWDWM System. All the systems are economically and technically feasible as a solar distillation system for potable water in Northern Cyprus. The price of potable water from water vendors/hawkers ranges from 0.11-0.16 $/L. It is more economically viable to have the rooftop inclined solar water desalination system than procuring potable water from vendors.`

  13. Solar technology assessment project. Volume 3: Active space heating and hot water supply with solar energy

    Science.gov (United States)

    Karaki, S.; Loef, G. O. G.

    1981-04-01

    Several types of solar water heaters are described and assessed. These include thermosiphon water heaters and pump circulation water heaters. Auxiliary water heating is briefly discussed, and new and retrofit systems are compared. Liquid-based space heating systems and solar air heaters are described and assessed, auxiliary space heating are discussed, and new and retrofit solar space heating systems are compared. The status of flat plate collectors, evacuated tube collectors, and thermal storage systems is examined. Systems improvements, reliability, durability and maintenance are discussed. The economic assessment of space and water heating systems includes a comparison of new systems costs with conventional fuels, and sales history and projections. The variety of participants in the solar industry and users of solar heat is discussed, and various incentives and barriers to solar heating are examined. Several policy implications are discussed, and specific government actions are recommended.

  14. Renewable Water: Direct Contact Membrane Distillation Coupled With Solar Ponds

    Science.gov (United States)

    Suarez, F. I.; Tyler, S. W.; Childress, A. E.

    2010-12-01

    The exponential population growth and the accelerated increase in the standard of living have increased significantly the global consumption of two precious resources: water and energy. These resources are intrinsically linked and are required to allow a high quality of human life. With sufficient energy, water may be harvested from aquifers, treated for potable reuse, or desalinated from brackish and seawater supplies. Even though the costs of desalination have declined significantly, traditional desalination systems still require large quantities of energy, typically from fossil fuels that will not allow these systems to produce water in a sustainable way. Recent advances in direct contact membrane distillation can take advantage of low-quality or renewable heat to desalinate brackish water, seawater or wastewater. Direct contact membrane distillation operates at low pressures and can use small temperature differences between the feed and permeate water to achieve a significant freshwater production. Therefore, a much broader selection of energy sources can be considered to drive thermal desalination. A promising method for providing renewable source of heat for direct contact membrane distillation is a solar pond, which is an artificially stratified water body that captures solar radiation and stores it as thermal energy at the bottom of the pond. In this work, a direct contact membrane distillation/solar pond coupled system is modeled and tested using a laboratory-scale system. Freshwater production rates on the order of 2 L day-1 per m2 of solar pond (1 L hr-1 per m2 of membrane area) can easily be achieved with minimal operating costs and under low pressures. While these rates are modest, they are six times larger than those produced by other solar pond-powered desalination systems - and they are likely to be increased if heat losses in the laboratory-scale system are reduced. Even more, this system operates at much lower costs than traditional desalination

  15. Field performance of photovoltaic solar water heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Fanney, A.H.; Dougherty, B.P.; Kramp, K.P. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Building Environment Div.

    1997-11-01

    Energy consumed for water heating accounts for approximately 17.9 EJ of the energy consumed by residential and commercial buildings. Although there are over 90 million water heaters currently in use within the United States, durability and installation issues as well as initial cost have limited the sales of solar water heaters to less than 1 million units. Durability issues have included freeze and fluid leakage problems, failure of pumps and their associated controllers, the loss of heat transfer fluids under stagnation conditions, and heat exchanger fouling. The installation of solar water heating systems has often proved difficult, requiring roof penetrations for the piping that transports fluid to and from the solar collectors. Fanney and Dougherty have recently proposed and patented a solar water heating system that eliminates the durability and installation problems associated with current solar water heating systems. The system employs photovoltaic modules to generate electrical energy which is dissipated in multiple electric heating elements. A microprocessor controller is used to match the electrical resistance of the load to the operating characteristics of the photovoltaic modules. Although currently more expensive than existing solar hot water systems, photovoltaic solar water heaters offer the promise of being less expensive than solar thermal systems within the next decade. To date, photovoltaic solar water heating systems have been installed at the National Institute of Standards and Technology in Gaithersburg, MD and the Florida Solar Energy Center in Cocoa, FL. This paper will review the technology employed, describe the two photovoltaic solar water heating systems, and present measured performance data.

  16. Disinfection of contaminated water by using solar irradiation.

    Science.gov (United States)

    Caslake, Laurie F; Connolly, Daniel J; Menon, Vilas; Duncanson, Catriona M; Rojas, Ricardo; Tavakoli, Javad

    2004-02-01

    Contaminated water causes an estimated 6 to 60 billion cases of gastrointestinal illness annually. The majority of these cases occur in rural areas of developing nations where the water supply remains polluted and adequate sanitation is unavailable. A portable, low-cost, and low-maintenance solar unit to disinfect unpotable water has been designed and tested. The solar disinfection unit was tested with both river water and partially processed water from two wastewater treatment plants. In less than 30 min in midday sunlight, the unit eradicated more than 4 log10 U (99.99%) of bacteria contained in highly contaminated water samples. The solar disinfection unit has been field tested by Centro Panamericano de Ingenieria Sanitaria y Ciencias del Ambiente in Lima, Peru. At moderate light intensity, the solar disinfection unit was capable of reducing the bacterial load in a controlled contaminated water sample by 4 log10 U and disinfected approximately 1 liter of water in 30 min.

  17. Towards Highly Efficient Bias-Free Solar Water Splitting

    NARCIS (Netherlands)

    Abdi, F.F.

    2013-01-01

    Solar water splitting has attracted significant attention due to its potential of converting solar to chemical energy. It uses semiconductor to convert sunlight into electron-hole pairs, which then split water into hydrogen and oxygen. The hydrogen can be used as a renewable fuel, or it can serve as

  18. Towards Highly Efficient Bias-Free Solar Water Splitting

    NARCIS (Netherlands)

    Abdi, F.F.

    2013-01-01

    Solar water splitting has attracted significant attention due to its potential of converting solar to chemical energy. It uses semiconductor to convert sunlight into electron-hole pairs, which then split water into hydrogen and oxygen. The hydrogen can be used as a renewable fuel, or it can serve as

  19. Novel configurations of solar distillation system for potable water production

    Science.gov (United States)

    Riahi, A.; Yusof, K. W.; Sapari, N.; Singh, B. S.; Hashim, A. M.

    2013-06-01

    More and more surface water are polluted with toxic chemicals. Alternatively brackish and saline water are used as feed water to water treatment plants. Expensive desalination process via reverse osmosis or distillation is used in the plants. Thus, this conventional desalination is not suitable for low and medium income countries. A cheaper method is by solar distillation. However the rate of water production by this method is generally considered low. This research attempts to enhance water production of solar distillation by optimizing solar capture, evaporation and condensation processes. Solar radiation data was captured in several days in Perak, Malaysia. Three kinds of experiments were done by fabricating triangular solar distillation systems. First type was conventional solar still, second type was combined with 50 Watt solar photovoltaic panel and 40 Watt Dc heater, while third type was integrated with 12 Volt Solar battery and 40 Watt Dc heater. The present investigation showed that the productivity of second and third systems were 150% and 480% of the conventional still type, respectively. The finding of this research can be expected to have wide application in water supply particularly in areas where fresh surface water is limited.

  20. Two-Step Water Splitting with Concentrated Solar Heat Using Rotary-Type Solar Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, H.; Fuse, A.; Miura, T.; Ishihara, H.; Tamara, Y.

    2006-07-01

    The rotary-type solar furnace has been developed and fabricated for solar hydrogen production by a two-step water splitting reaction using the special reactive ceramic. The rotary-type solar furnace is the dual cell solar reactor, which has two different type reaction rooms, one is for discharging oxygen and another is for water splitting reaction. The detailed specification and the efficiency of the rotary-type solar furnace were examined. Successive evolutions of oxygen and hydrogen were observed in the discharging oxygen and water splitting reaction cells, respectively. Two-step water splitting process using newly developed rotary type solar furnace was achieved. The optimum reaction temperatures of the oxygen releasing reaction and hydrogen generation reaction with Ni,Mn-ferrite were 1173 K and 1473 K, respectively. (Author)

  1. Comparative Study and Design of Solar Water Heater

    Directory of Open Access Journals (Sweden)

    K.Sainath,Y.krishna, Mohd Salahuddin, Mohammed Siddique Ahmed, Md Ismail, Syed Rahman,Mohammed Noman, Mohd Khaleel Ullah, Faraz Ur Rehman Azhar, Mohd Moizuddin,Mohd Riyaz Uddin.

    2014-10-01

    Full Text Available A solar water heater design is made from the plastic bottles of thumps up & plastic pipe(p.v.c run up by the centre of each solar heater in a row of bottles, these bottles act as glazing & hold reflectors made from the black paint. Solar water heaters are made of two basic parts: a solar collector that gathers radiant energy and a storage tank for the hot water inside. These systems are used to heat water for swimming pools, as well as for domestic cooking and cleaning needs. A system in which the sun’s heat is gathered by a solar collector and used to increase the temperature of a heat-transfer fluid , which flows through the pipes in the collector; the heat contained in this fluid then is conveyed and transferred to the water to be heated. Solar water heaters use the solar energy from the sun to generate heat (not electricity which can then be used to heat water for showering, space heating, industrial processes or even solar cooling. However, the research shows that the electric water spends about the 25% of its home energy costs on heating water. If we make a water heater without the collector then we can save a lot of money solar water heater do not polluted if one investing on SWH avoids carbon dioxide nitrogen oxide and sulphur dioxide and the other air pollution wastes and the utility generates power on your bum fuel to heat your household water when SWH replaces the an electric water heater. This electric displaced over 20 years replaced more than 50 tones avoided c02 emissions alone co2 traps heat in the upper most atmosphere thus, contributing to the ‘Green House Effect

  2. Solar heating of the produced water of petroleum; Aquecimento solar da agua produzida de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Rogerio Pitanga; Chiavone-Filho, Osvaldo; Bezerra, Magna A. Santos; Melo, Josette Lourdes Sousa de; Oliveira, Jackson Araujo de; Ramos, Rafael E. Moura [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Schuhli, Juliana Bregenski; Andrade, Vivian Tavares de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    In this work, experimental data of solar heating for common water and saline solution were measured. The solar heater is formed by a flat-plane collector and a thermal reservoir ('boiler'). The objective is to quantify the variation of fluids' temperature, and correlate it to environment variables, especially solar irradiation. Thereby, it is possible to estimate the solar heating of produced water of petroleum. The solar heater is part of a system of treatment of produced water, and its function is to pre-heat the fluid that enters into the solar distiller, increasing the productivity of distilled water. A saline solution that represents produced water was used in the experiments, using sodium chloride (1000 ppm). The experimental data demonstrates that the solar heater is capable to heat the fluid to temperatures close to 70 deg C, reaching temperatures close to 50 deg C even during cloudy days with low solar radiation. Furthermore, the solar collector energy system provides a higher rate of heating and trough of the thermal reservoir the temperature can remain longer. These are important aspects to the integration with solar distillation. (author)

  3. Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

    Directory of Open Access Journals (Sweden)

    Xu Ji

    2015-01-01

    Full Text Available The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to 90°, the variation was up to 20%. The effects of water cycle mode, reverse slope placement of solar collector, and water tank installation height on system efficiency were experimentally studied. The thermal efficiencies of solar water heater with single row horizontal arrangement all-glass evacuated tubular collector were higher than those with vertical arrangement at the fixed surface slope angle of 90°. Compared with solar water heaters with flat-plate collector under natural circulation, the system thermal efficiency was raised up to 63% under forced circulation. For collector at reverse slope placement, the temperature-based water stratification in water tank deteriorated, and thus the thermal efficiency became low. For improving the system efficiency, an appropriate installation height of the water tank was suggested.

  4. Optimum hot water temperature for absorption solar cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)

    2009-10-15

    The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

  5. Solar Distillation Practice For Water Desalination Systems

    OpenAIRE

    Mahian, Omid; Kianifar, Ali; Jumpholkul, Chaiwat; Thiangtham, Phubate; Wongwises, Somchai; Srisomba, Raviwat

    2015-01-01

    references, it is suggested to add a chapter concerning CFD simulations of solar stills. In addition, a part can be devoted to using novel technologies such as nanotechnology for productivity enhancement of solar stills

  6. Active space heating and hot water supply with solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Karaki, S.; Loef, G. O.G.

    1981-04-01

    Technical and economic assessments are given of solar water heaters, both circulating, and of air-based and liquid-based solar space heating systems. Both new and retrofit systems are considered. The technical status of flat-plate and evacuated tube collectors and of thermal storage is also covered. Non-technical factors are also briefly discussed, including the participants in the use of solar heat, incentives and deterrents. Policy implications are considered as regards acceleration of solar use, goals for solar use, means for achieving goals, and interaction of governments, suppliers, and users. Government actions are recommended. (LEW)

  7. Semi-empirical model of solar plages

    Institute of Scientific and Technical Information of China (English)

    FANG; Cheng

    2001-01-01

    [1] Zirin, H., Astrophysics of the Sun, Chapter 7, Cambridge: Cambridge University Press, 1988.[2] Shine, R. A., Linsky, J. L., Physical properties of solar chromospheric plages II. Chromospheric plage models, Solar Phys., 1974, 39: 49.[3] Kelch, W. L., Linsky, J. L., Physical properties of solar chromospheric plages III. Models based on CaII and MgII observations, Solar Phys., 1978, 58: 37.[4] Lemaire, P., Goutlebroze, J. C., Vial, J. C. et al., Physical properties of the solar chromosphere deduced from optically thick lines, A & A, 1981, 103: 160.[5] Fontenla, J. M., Avrett, E. H., Loeser, R., Energy balance in the solar transition region II. Effects of pressure and energy input on hydrostatic models, ApJ, 1991, 377: 712.[6] Fontenla, J. M., Avrett, E. H., Loeser, R., Energy balance in the solar transition region III. Helium emission in hydrostatic, constant-abundance models with diffusion, ApJ, 1993, 406: 319.[7] Pierce, A. K., Slaughter, C., Solar limb darkening I: λλ(30337297), Solar Phys., 1977, 51: 25.[8] Pierce, A. K., Slaughter, C., Weinberger, D., Solar limb darkening in the interval 740424018*!, II, Solar Phys., 1977, 52: 179.[9] Nechel, H., Labs, D., The solar radiation between 3300 and 12500*!, Solar Phys., 1984, 90: 205.[10] Vernazza, J. E., Avrett, E. H., Loeser, R., Structure of the solar chromosphere I. Basic computations and summary of the results, ApJ, 1973, 184: 605.[11] Mihalas, D., Stellar Atmospheres, San Francisco: W. H. Freeman and Company, 1978.[12] Fang, C., Hnoux, J. -C., Self-consistent model of flare heated solar chromosphere, A & A, 1983, 118: 139.[13] Ding, M. D., Fang, C., A semi-empirical model of sunspot penumbra, A & A, 1989, 225: 204.[14] Vernazza, J. E., Avrett, E. H., Loeser, R., Structure of the solar chromosphere III. Models of the EUV brightness components of the quiet Sun, ApJ Suppl., 1981, 45: 635.[15] Canfield, R. C., Athey, R

  8. Potential for solar water heating in Zimbabwe

    Energy Technology Data Exchange (ETDEWEB)

    Batidzirai, Bothwell [Department of Science, Technology and Society, Copernicus Institute for Sustainable Development and Innovation, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht (Netherlands)]|[Department of Fuels and Energy, School of Engineering Science and Technology, Chinhoyi University of Technology, P. Bag 7724, Chinhoyi (Zimbabwe); Lysen, Erik H.; Van Egmond, Sander [Utrecht Centre for Energy Research (UCE), Utrecht University, Heidelberglaan 2, 3584 CS Utrecht (Netherlands); Van Sark, Wilfried G.J.H.M. [Department of Science, Technology and Society, Copernicus Institute for Sustainable Development and Innovation, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht (Netherlands)

    2009-04-15

    This paper discusses the economic, social and environmental benefits from using solar water heating (SWH) in Zimbabwe. By comparing different water heating technology usage in three sectors over a 25-year period, the potential of SWH is demonstrated in alleviating energy and economic problems that energy-importing countries like Zimbabwe are facing. SWH would reduce coincident electricity winter peak demand by 13% and reduce final energy demand by 27%, assuming a 50% penetration rate of SWH potential demand. Up to $250 million can be saved and CO{sub 2} emissions can be reduced by 29% over the 25-year period. Benefits are also present at individual consumer level, for the electricity utility, as well as for society at large. In the case of Zimbabwe, policy strategies that can support renewable energy technologies are already in current government policy, but this political will need to be translated into enhanced practical activities. A multi-stakeholder approach appears to be the best approach to promoting widespread dissemination of SWH technologies. (author)

  9. Implications of solar wind measurements for solar models and composition

    CERN Document Server

    Serenelli, Aldo; Villante, Francesco L; Vincent, Aaron C; Asplund, Martin; Basu, Sarbani; Grevesse, Nicolas; Pena-Garay, Carlos

    2016-01-01

    We critically examine recent claims of a high solar metallicity by von Steiger \\& Zurbuchen (2016; vSZ16) based on in situ measurements of the solar wind, rather than the standard spectroscopically-inferred abundances (Asplund et al. 2009). We test the claim by Vagnozzi et al. (2016) that a composition based on the solar wind enables one to construct a standard solar model in agreement with helioseismological observations and thus solve the decades-old solar modelling problem. We show that, although some helioseismological observables are improved compared to models computed with established abundances, most are in fact worse. The high abundance of refractory elements leads to an overproduction of neutrinos, with a predicted $^8$B flux that is nearly twice its observed value, and $^7$Be and CNO fluxes that are experimentally ruled out at high confidence. A combined likelihood analysis shows that models using the vSZ16 abundances fare much worse than AGSS09 despite a higher metallicity. We also present ast...

  10. Mathematical model development for a new solar desalination system (SDS)

    Energy Technology Data Exchange (ETDEWEB)

    Elsafty, A.F. [Arab Academy for Science and Technology and Maritime Transport, Alexandria (Egypt). Dept. of Mechanical and Marine Engineering; Fath, H.E. [Alexandria Univ., Alexandria (Egypt). Dept. of Mechanical Engineering

    2007-07-01

    Desalination, as a non-conventional water resource, has become one of the most promising alternative water sources to address the fresh water shortage in the near future. Desalination technologies are constrained in that they are driven almost entirely by the combustion of fuels which are still of finite supply, pollute the air, and contribute to the risk of global climate change. Solar distillation is preferred to other processes of distillation because of the low operating cost, low maintenance, lack of moving parts, and clean energy offered. The development of solar distillation has demonstrated its suitability for saline water desalination when weather conditions are favorable and when demand is not large. Solar energy in the Arab region is available at relatively high intensity during most of the year. This paper presented a general mathematical model for a newly developed solar still that uses a parabolic reflector-tube absorber desalination technology. A computer program was developed to simulate the still operation and to solve the governing heat and mass transfer action which occurred during the operation. The program was used to study the still production in different cases. The paper provided a description of the mathematical model and discussed the governing equations. It was concluded that unit productivity improved by increasing the solar intensity, ambient temperature, efficiency of reflector material, reflector aperture area and evaporation area. In addition, increasing the wind velocity, saline water depth, condenser emissivity and condenser thickness had only a small effect on the productivity. 3 refs., 1 tab., 14 figs.

  11. Modeling the Photocatalytic Mineralization in Water of Commercial Formulation of Estrogens 17-β Estradiol (E2 and Nomegestrol Acetate in Contraceptive Pills in a Solar Powered Compound Parabolic Collector

    Directory of Open Access Journals (Sweden)

    José Colina-Márquez

    2015-07-01

    Full Text Available Endocrine disruptors in water are contaminants of emerging concern due to the potential risks they pose to the environment and to the aquatic ecosystems. In this study, a solar photocatalytic treatment process in a pilot-scale compound parabolic collector (CPC was used to remove commercial estradiol formulations (17-β estradiol and nomegestrol acetate from water. Photolysis alone degraded up to 50% of estradiol and removed 11% of the total organic carbon (TOC. In contrast, solar photocatalysis degraded up to 57% of estrogens and the TOC removal was 31%, with 0.6 g/L of catalyst load (TiO2 Aeroxide P-25 and 213.6 ppm of TOC as initial concentration of the commercial estradiols formulation. The adsorption of estrogens over the catalyst was insignificant and was modeled by the Langmuir isotherm. The TOC removal via photocatalysis in the photoreactor was modeled considering the reactor fluid-dynamics, the radiation field, the estrogens mass balance, and a modified Langmuir–Hinshelwood rate law, that was expressed in terms of the rate of photon adsorption. The optimum removal of the estrogens and TOC was achieved at a catalyst concentration of 0.4 g/L in 29 mm diameter tubular CPC reactors which approached the optimum catalyst concentration and optical thickness determined from the modeling of the absorption of solar radiation in the CPC, by the six-flux absorption-scattering model (SFM.

  12. Modeling the photocatalytic mineralization in water of commercial formulation of estrogens 17-β estradiol (E2) and nomegestrol acetate in contraceptive pills in a solar powered compound parabolic collector.

    Science.gov (United States)

    Colina-Márquez, José; Machuca-Martínez, Fiderman; Li Puma, Gianluca

    2015-07-22

    Endocrine disruptors in water are contaminants of emerging concern due to the potential risks they pose to the environment and to the aquatic ecosystems. In this study, a solar photocatalytic treatment process in a pilot-scale compound parabolic collector (CPC) was used to remove commercial estradiol formulations (17-β estradiol and nomegestrol acetate) from water. Photolysis alone degraded up to 50% of estradiol and removed 11% of the total organic carbon (TOC). In contrast, solar photocatalysis degraded up to 57% of estrogens and the TOC removal was 31%, with 0.6 g/L of catalyst load (TiO2 Aeroxide P-25) and 213.6 ppm of TOC as initial concentration of the commercial estradiols formulation. The adsorption of estrogens over the catalyst was insignificant and was modeled by the Langmuir isotherm. The TOC removal via photocatalysis in the photoreactor was modeled considering the reactor fluid-dynamics, the radiation field, the estrogens mass balance, and a modified Langmuir-Hinshelwood rate law, that was expressed in terms of the rate of photon adsorption. The optimum removal of the estrogens and TOC was achieved at a catalyst concentration of 0.4 g/L in 29 mm diameter tubular CPC reactors which approached the optimum catalyst concentration and optical thickness determined from the modeling of the absorption of solar radiation in the CPC, by the six-flux absorption-scattering model (SFM).

  13. Classifications of central solar domestic hot water systems

    Science.gov (United States)

    Guo, J. Y.; Hao, B.; Peng, C.; Wang, S. S.

    2016-08-01

    Currently, there are many means by which to classify solar domestic hot water systems, which are often categorized according to their scope of supply, solar collector positions, and type of heat storage tank. However, the lack of systematic and scientific classification as well as the general disregard of the thermal performance of the auxiliary heat source is important to DHW systems. Thus, the primary focus of this paper is to determine a classification system for solar domestic hot water systems based on the positions of the solar collector and auxiliary heating device, both respectively and in combination. Field-testing data regarding many central solar DHW systems demonstrates that the position of the auxiliary heat source clearly reflects the operational energy consumption. The consumption of collective auxiliary heating hot water system is much higher than individual auxiliary heating hot water system. In addition, costs are significantly reduced by the separation of the heat storage tank and the auxiliary heating device.

  14. Origins of Water in the Solar System Leading to Habitable Worlds

    Science.gov (United States)

    Meech, Karen J.

    2015-08-01

    Life on Earth depends on an aqueous biochemistry, and water is a key component of habitability on Earth and for likely other habitable environments in the solar system. While water is ubiquitous in the interstellar medium, and plays a key role in protoplanetary disk chemistry, the inner solar system is relatively dry. We now have evidence for potentially thousands of extrasolar planets, dozens of which may be located in their host star’s habitable zones. Understanding how planets in the habitable zone accrete their water, is key to understanding the likelihood for habitability. Given that many disk models show that Earth formed inside the water-ice snow line of our solar system, understanding how the inner solar system received its water is important for understanding the potential for other planetary systems to host habitable worlds. Boundaries for the timing of the water delivery are constrained by cosmochemistry and geochemistry. Possible scenarios for the delivery of water to the inner solar system include adsorption on dust from protoplanetary disk gas, chemical reactions on the early earth, and delivery from planetesimals forming outside the water-ice snow line. This talk will set the stage for understanding the isotopic and geochemical markers along with the dynamical delivery mechanisms that will help uncover the origins of Earths water. This introduction will provide an overview for understanding the distribution of water in the solar system, in particular for the inner solar system and terrestrial planets—and the details will be developed in the subsequent talks. Additionally information will be presented regarding new inner solar system reservoirs of water that can shed light on origins (the main belt comets), and new research about water in the Earth.

  15. Analysis and modeling of solar irradiance variations

    CERN Document Server

    Yeo, K L

    2014-01-01

    A prominent manifestation of the solar dynamo is the 11-year activity cycle, evident in indicators of solar activity, including solar irradiance. Although a relationship between solar activity and the brightness of the Sun had long been suspected, it was only directly observed after regular satellite measurements became available with the launch of Nimbus-7 in 1978. The measurement of solar irradiance from space is accompanied by the development of models aimed at describing the apparent variability by the intensity excess/deficit effected by magnetic structures in the photosphere. The more sophisticated models, termed semi-empirical, rely on the intensity spectra of photospheric magnetic structures generated with radiative transfer codes from semi-empirical model atmospheres. An established example of such models is SATIRE-S (Spectral And Total Irradiance REconstruction for the Satellite era). One key limitation of current semi-empirical models is the fact that the radiant properties of network and faculae a...

  16. Solar energy driven photocatalytic membrane modules for water reuse in agricultural and food industries. Pre-industrial experience using s-triazines as model molecules

    OpenAIRE

    Ignazio Renato Bellobono; Franca Morazzoni; Riccardo Bianchi; Emilia Simona Mangone; Rodica Stanescu; Cristina Costache; Paola Maria Tozzi

    2005-01-01

    A membrane module, utilizing photocatalytic membranes, has been employed in a pilot plant, in conditions of solar irradiation, to investigate photomineralisation of atrazine, propazine, terbutylazine, symazine, prometryn, and ametryn, as model molecules of s-triazine herbicides, at a standard concentration (1.0 ppm) simulating those of contaminated aquifers, by using ozone as oxygen supplier. Photocatalytic composite membranes immobilised 30±3 wt.% of TiO2 and 6 wt.% of a synergic mixture of ...

  17. Design package for solar domestic hot water system

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    Information used to evaluate the initial design of the Elcam, Inc., Solar Domestic Hot Water System is presented. Included are such items as the system performance specification, detailed design drawings and other information. Elcam, Inc., has developed two solar heated prototype hot water systems and two heat exchangers. The hot water systems consist of the following subsystems: collector, storage, control, transport, auxiliary energy, and government-furnished Site Data Acquisition. The two systems are installed at Tempe, Arizona, and San Diego, California.

  18. Design package for solar domestic hot water system

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    Information used to evaluate the initial design of the Elcam, Inc., Solar Domestic Hot Water System is presented. Included are such items as the system performance specification, detailed design drawings and other information. Elcam, Inc., has developed two solar heated prototype hot water systems and two heat exchangers. The hot water systems consist of the following subsystems: collector, storage, control, transport, auxiliary energy, and government-furnished Site Data Acquisition. The two systems are installed at Tempe, Arizona, and San Diego, California.

  19. Solar parameters for modeling interplanetary background

    CERN Document Server

    Bzowski, M; Tokumaru, M; Fujiki, K; Quemerais, E; Lallement, R; Ferron, S; Bochsler, P; McComas, D J

    2011-01-01

    The goal of the Fully Online Datacenter of Ultraviolet Emissions (FONDUE) Working Team of the International Space Science Institute in Bern, Switzerland, was to establish a common calibration of various UV and EUV heliospheric observations, both spectroscopic and photometric. Realization of this goal required an up-to-date model of spatial distribution of neutral interstellar hydrogen in the heliosphere, and to that end, a credible model of the radiation pressure and ionization processes was needed. This chapter describes the solar factors shaping the distribution of neutral interstellar H in the heliosphere. Presented are the solar Lyman-alpha flux and the solar Lyman-alpha resonant radiation pressure force acting on neutral H atoms in the heliosphere, solar EUV radiation and the photoionization of heliospheric hydrogen, and their evolution in time and the still hypothetical variation with heliolatitude. Further, solar wind and its evolution with solar activity is presented in the context of the charge excha...

  20. Saving cost in solar water heaters by means of integration of the solar equipment in an existing hot water circulation loop; Kosteneinsparungen bei solaren Warmwasseranlagen durch Einbindung in die Warmwasserzirkulation. Vorstudie

    Energy Technology Data Exchange (ETDEWEB)

    Sitzmann, B.

    2001-07-01

    The implementation of solar water heaters in hot-water circulations for apartment buildings was examined. Models as well as investigations at 6 water supply systems in existing buildings show technically and economically opportunities for the proposed installation. Beside a reduction of the solar-piping length the proposed system shows higher opportunities for using existing hot water storage devices for solar energy storage. This is because of the energy transfer at the hot water storage devices from the existing in- and outlets instead of a heat exchanger. Today the proposed installation can be already classified as economic useful if the investment for piping and additional hot water storage device can be reduced in comparison to conventional solar water heaters. Further optimisation can be seen in the simple installation of the solar water heater to improve the economic efficiency of the proposed system. (author)

  1. Is there a solar signal in lower stratospheric water vapour?

    Science.gov (United States)

    Schieferdecker, Tobias; Lossow, Stefan; Stiller, Gabriele; von Clarmann, Thomas

    2016-04-01

    A merged time series of stratospheric water vapour built from the Halogen Occultation Instrument (HALOE) and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) data between 60 deg S and 60 deg N and 15 to 30 km, and covering the years 1992 to 2012, was analysed by multivariate linear regression, including an 11-year solar cycle proxy. Lower stratospheric water vapour was found to reveal a phase-shifted anti-correlation with the solar cycle, with lowest water vapour after solar maximum. The phase shift is composed of an inherent constant time lag of about 2 years and a second component following the stratospheric age of air. The amplitudes of the water vapour response are largest close to the tropical tropopause (up to 0.35 ppmv) and decrease with altitude and latitude. Including the solar cycle proxy in the regression results in linear trends of water vapour being negative over the full altitude/latitude range, while without the solar proxy, positive water vapour trends in the lower stratosphere were found. We conclude from these results that a solar signal seems to be generated at the tropical tropopause which is most likely imprinted on the stratospheric water vapour abundances and transported to higher altitudes and latitudes via the Brewer-Dobson circulation. Hence it is concluded that the tropical tropopause temperature at the final dehydration point of air may also be governed to some degree by the solar cycle. The negative water vapour trends obtained when considering the solar cycle impact on water vapour abundances can possibly solve the "water vapour conundrum" of increasing stratospheric water vapour abundances despite constant or even decreasing tropopause temperatures.

  2. Wave Modeling of the Solar Wind.

    Science.gov (United States)

    Ofman, Leon

    The acceleration and heating of the solar wind have been studied for decades using satellite observations and models. However, the exact mechanism that leads to solar wind heating and acceleration is poorly understood. In order to improve the understanding of the physical mechanisms that are involved in these processes a combination of modeling and observational analysis is required. Recent models constrained by satellite observations show that wave heating in the low-frequency (MHD), and high-frequency (ion-cyclotron) range may provide the necessary momentum and heat input to coronal plasma and produce the solar wind. This review is focused on the results of several recent solar modeling studies that include waves explicitly in the MHD and the kinetic regime. The current status of the understanding of the solar wind acceleration and heating by waves is reviewed.

  3. A successful solar model using new solar composition data

    CERN Document Server

    Vagnozzi, Sunny; Zurbuchen, Thomas H

    2016-01-01

    A resolution is proposed to the "solar abundance problem", that is, the discrepancy between helioseismological observations and the predictions of solar models, computed implementing state-of-the-art photospheric abundances. We reassess the problem considering a newly determined set of abundances, which indicate a lower limit to the metallicity of $Z_{\\odot} = 0.0196 \\pm 0.0014$, significantly higher than findings during the past decade. Such value for the metallicity is determined in situ, measuring the least fractionated solar winds over the poles of the Sun, rather than spectroscopically. We determine the response of helioseismological observables to the corresponding changes in elemental abundances. Our findings indicate that, taking inversion errors into account, good agreement between models and observations is achieved. The definitive test for these abundances will be measurements of the CNO neutrino fluxes by SNO$^+$ (which we expect to be $\\sim$ 30-50\\% higher than predictions using abundances based ...

  4. Standard solar model. II - g-modes

    Science.gov (United States)

    Guenther, D. B.; Demarque, P.; Pinsonneault, M. H.; Kim, Y.-C.

    1992-01-01

    The paper presents the g-mode oscillation for a set of modern solar models. Each solar model is based on a single modification or improvement to the physics of a reference solar model. Improvements were made to the nuclear reaction rates, the equation of state, the opacities, and the treatment of the atmosphere. The error in the predicted g-mode periods associated with the uncertainties in the model physics is predicted and the specific sensitivities of the g-mode periods and their period spacings to the different model structures are described. In addition, these models are compared to a sample of published observations. A remarkably good agreement is found between the 'best' solar model and the observations of Hill and Gu (1990).

  5. Enhancement of Solar Energy Representation in the GCAM Model

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven J.; Volke, April C.; Delgado Arias, Sabrina

    2010-02-01

    The representation of solar technologies in a research version of the GCAM (formerly MiniCAM) integrated assessment model have been enhanced to add technologies, improve the underlying data, and improve the interaction with the rest of the model. We find that the largest potential impact from the inclusion of thermal Concentrating Solar Power plants, which supply a substantial portion of electric generation in sunny regions of the world. Drawing on NREL research, domestic Solar Hot Water technologies have also been added in the United States region where this technology competes with conventional electric and gas technologies. PV technologies are as implemented in the CCTP scenarios, drawing on NREL cost curves for the United States, extrapolated to other world regions using a spatial analysis of population and solar resources.

  6. The analysis of solar models: Neutrinos and oscillations

    Science.gov (United States)

    Ulrich, R. K.; Rhodes, E. J., Jr.; Tomczyk, S.; Dumont, P. J.; Brunish, W. M.

    1983-01-01

    Tests of solar neutrino flux and solar oscillation frequencies were used to assess standard stellar structure theory. Standard and non-standard solar models are enumerated and discussed. The field of solar seismology, wherein the solar interior is studied from the measurement of solar oscillations, is introduced.

  7. Solar water heaters in China: A new day dawning

    NARCIS (Netherlands)

    Han, Jingyi; Mol, A.P.J.; Lu, Y.

    2010-01-01

    Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in China in recent decades. Manufacturing and marketing developments have been especially strong in provinces such as Zhejiang, Shandong and Jiangsu. This paper takes Zhejiang, a relatively

  8. Design and installation package for solar hot water system

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    This report contains the design and installation procedure for the Solar Engineering and Manufacturing Company's solar hot water system. Included are the system performance specifications, system design drawings, hazard analysis and other information necessary to evaluate the design and instal the system.

  9. Solar High Temperature Water-Splitting Cycle with Quantum Boost

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Robin [SAIC; Davenport, Roger [SAIC; Talbot, Jan [UCSD; Herz, Richard [UCSD; Genders, David [Electrosynthesis Co.; Symons, Peter [Electrosynthesis Co.; Brown, Lloyd [TChemE

    2014-04-25

    A sulfur family chemical cycle having ammonia as the working fluid and reagent was developed as a cost-effective and efficient hydrogen production technology based on a solar thermochemical water-splitting cycle. The sulfur ammonia (SA) cycle is a renewable and sustainable process that is unique in that it is an all-fluid cycle (i.e., with no solids handling). It uses a moderate temperature solar plant with the solar receiver operating at 800°C. All electricity needed is generated internally from recovered heat. The plant would operate continuously with low cost storage and it is a good potential solar thermochemical hydrogen production cycle for reaching the DOE cost goals. Two approaches were considered for the hydrogen production step of the SA cycle: (1) photocatalytic, and (2) electrolytic oxidation of ammonium sulfite to ammonium sulfate in aqueous solutions. Also, two sub-cycles were evaluated for the oxygen evolution side of the SA cycle: (1) zinc sulfate/zinc oxide, and (2) potassium sulfate/potassium pyrosulfate. The laboratory testing and optimization of all the process steps for each version of the SA cycle were proven in the laboratory or have been fully demonstrated by others, but further optimization is still possible and needed. The solar configuration evolved to a 50 MW(thermal) central receiver system with a North heliostat field, a cavity receiver, and NaCl molten salt storage to allow continuous operation. The H2A economic model was used to optimize and trade-off SA cycle configurations. Parametric studies of chemical plant performance have indicated process efficiencies of ~20%. Although the current process efficiency is technically acceptable, an increased efficiency is needed if the DOE cost targets are to be reached. There are two interrelated areas in which there is the potential for significant efficiency improvements: electrolysis cell voltage and excessive water vaporization. Methods to significantly reduce water evaporation are

  10. The ancient heritage of water ice in the solar system

    CERN Document Server

    Cleeves, L Ilsedore; Alexander, Conel M O'D; Du, Fujun; Graninger, Dawn; Öberg, Karin I; Harries, Tim J

    2014-01-01

    Identifying the source of Earth's water is central to understanding the origins of life-fostering environments and to assessing the prevalence of such environments in space. Water throughout the solar system exhibits deuterium-to-hydrogen enrichments, a fossil relic of low-temperature, ion-derived chemistry within either (i) the parent molecular cloud or (ii) the solar nebula protoplanetary disk. Utilizing a comprehensive treatment of disk ionization, we find that ion-driven deuterium pathways are inefficient, curtailing the disk's deuterated water formation and its viability as the sole source for the solar system's water. This finding implies that if the solar system's formation was typical, abundant interstellar ices are available to all nascent planetary systems.

  11. The ancient heritage of water ice in the solar system.

    Science.gov (United States)

    Cleeves, L Ilsedore; Bergin, Edwin A; Alexander, Conel M O'D; Du, Fujun; Graninger, Dawn; Öberg, Karin I; Harries, Tim J

    2014-09-26

    Identifying the source of Earth's water is central to understanding the origins of life-fostering environments and to assessing the prevalence of such environments in space. Water throughout the solar system exhibits deuterium-to-hydrogen enrichments, a fossil relic of low-temperature, ion-derived chemistry within either (i) the parent molecular cloud or (ii) the solar nebula protoplanetary disk. Using a comprehensive treatment of disk ionization, we find that ion-driven deuterium pathways are inefficient, which curtails the disk's deuterated water formation and its viability as the sole source for the solar system's water. This finding implies that, if the solar system's formation was typical, abundant interstellar ices are available to all nascent planetary systems.

  12. New Home Buyer Solar Water Heater Trade-Off Study

    Energy Technology Data Exchange (ETDEWEB)

    Symmetrics Marketing Corporation

    1999-08-18

    This report details the results of a research conducted in 1998 and 1999 and outlines a marketing deployment plan designed for businesses interested in marketing solar water heaters in the new home industry.

  13. Creating a Comprehensive Solar Water Heating Deployment Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Focus Marketing Services

    1999-08-18

    This report details the results of a research conducted in 1998 and 1999 and outlines a marketing deployment plan designed for businesses interested in marketing solar water heaters in the new home industry.

  14. Modelling and verification of single slope solar still using ANSYS-CFX

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, Hitesh N. [Research Scholar, Kadi Sarvavishwavidyalaya University, Gandhinagar (India); Shah, P.K. [Principal, Silver Oak College of Engineering and Technology, Ahmedabad (India)

    2011-07-01

    Solar distillation method is an easy, small scale and cost effective technique for providing safe water. It requires an energy input as heat and the solar radiation can be source of energy. Solar still is a device which uses process of solar distillation. Here, a two phase, three dimensional model was made for evaporation as well as condensation process in solar still by using ANSYS CFX method to simulate the present model. Simulation results of solar still compared with actual experiment data of single basin solar still at climate conditions of Mehsana (23{sup o}12' N, 72{sup o}30'). There is a good agreement with experimental results and simulation results of distillate output, water temperature and heat transfer coefficients. Overall study shows the ANSYS CFX is a powerful tool for diagnostic as well as analysis of solar still.

  15. Design of a Solar Water Heating System for Kuti Hall, University of ...

    African Journals Online (AJOL)

    Design of a Solar Water Heating System for Kuti Hall, University of Ibadan, Ibadan. ... an energy audit to determine daily heating load and energy eliminated by Solar ... of solar collector and Cold water temperature calculated from weather data ...

  16. Solar-Powered Desalination: A Modelling and Experimental Study

    Science.gov (United States)

    Leblanc, Jimmy; Andrews, John

    2007-10-01

    Water shortage is becoming one of the major problems worldwide. As such, desalination technologies have been implemented to meet growing demands for fresh water. Among the desalination technologies, thermal desalination, including multi stage flash (MSF) and multi effect evaporation (MEE), is the current leading desalination process. Reverse osmosis (RO) is also being increasingly used. Despite technological improvements, thermal desalination and reverse osmosis continue to be intensive fossil-fuel consumers and contribute to increased levels of greenhouse gases. As energy costs rise, thermal desalination by solar energy and/or low cost waste heat is likely to become increasingly attractive. As part of a project investigating the productive use of saline land and the development of sustainable desalination systems, the feasibility of producing potable water from seawater or brackish water using desalination systems powered by renewable energy in the form of low-temperature solar-thermal sources has been studied. A salinity-gradient solar pond and an evacuated tube solar collector system have been used as heat sources. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90 °C. A visual basic computer model of the different multi-stage flash desalination processes coupled with a salinity-gradient solar pond was developed to determine which process is preferable in regards to performance and greenhouse impact. The governing mathematical equations are derived from mass balances, heat energy balances, and heat transfer characteristics. Using the results from the modelling, a small-scale solar-powered desalination system, capable of producing up to 500 litres of fresh water per day, was designed and manufactured. This single-stage flash system consists of two main units: the heat supply and storage system and the flash desalination unit. Two different condenser heat exchanger

  17. Global Solar Dynamo Models: Simulations and Predictions

    Indian Academy of Sciences (India)

    Mausumi Dikpati; Peter A. Gilman

    2008-03-01

    Flux-transport type solar dynamos have achieved considerable success in correctly simulating many solar cycle features, and are now being used for prediction of solar cycle timing and amplitude.We first define flux-transport dynamos and demonstrate how they work. The essential added ingredient in this class of models is meridional circulation, which governs the dynamo period and also plays a crucial role in determining the Sun’s memory about its past magnetic fields.We show that flux-transport dynamo models can explain many key features of solar cycles. Then we show that a predictive tool can be built from this class of dynamo that can be used to predict mean solar cycle features by assimilating magnetic field data from previous cycles.

  18. Solar space and water heating system installed at Charlottesville, Virginia

    Science.gov (United States)

    1980-01-01

    The solar energy system located at David C. Wilson Neuropsychiatric Hospital, Charlottesville, Virginia, is described. The solar energy system consists of 88 single glazed, Sunworks 'Solector' copper base plate collector modules, hot water coils in the hot air ducts, a Domestic Hot Water (DHW) preheat tank, a 3,000 gallon concrete urethane insulated storage tank and other miscellaneous components. Extracts from the site files, specifications, drawings, installation, operation and maintenance instructions are included.

  19. An innovative psychometric solar-powered water desalination system

    OpenAIRE

    Shatat, Mahmood; Riffat, Saffa; Gan, Guohui

    2016-01-01

    Important advances have been made in solar water desalination technology but their wide application is restricted by relatively high capital and running costs. Until recently, solar concentrator collectors had usually been employed to distill water in compact desalination systems. Currently, it is possible to replace these collectors by the more efficient evacuated tube collectors, which are now widely available on the market at lower prices. This paper describes the results of experimental a...

  20. Hot water from the sun: a consumer guide to solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, Beth

    2005-02-15

    The following topics are discussed: how solar water heaters work, making good use of the sun, estimating costs and savings, choosing the right dealer/installer, choosing the right system, warranties and contracts, getting a good installation, and living with your solar energy system. The appendices discuss system performance and durability, and provide sources of additional information on solar energy and its applications. (MHR)

  1. Tantalum-based semiconductors for solar water splitting.

    Science.gov (United States)

    Zhang, Peng; Zhang, Jijie; Gong, Jinlong

    2014-07-07

    Solar energy utilization is one of the most promising solutions for the energy crises. Among all the possible means to make use of solar energy, solar water splitting is remarkable since it can accomplish the conversion of solar energy into chemical energy. The produced hydrogen is clean and sustainable which could be used in various areas. For the past decades, numerous efforts have been put into this research area with many important achievements. Improving the overall efficiency and stability of semiconductor photocatalysts are the research focuses for the solar water splitting. Tantalum-based semiconductors, including tantalum oxide, tantalate and tantalum (oxy)nitride, are among the most important photocatalysts. Tantalum oxide has the band gap energy that is suitable for the overall solar water splitting. The more negative conduction band minimum of tantalum oxide provides photogenerated electrons with higher potential for the hydrogen generation reaction. Tantalates, with tunable compositions, show high activities owning to their layered perovskite structure. (Oxy)nitrides, especially TaON and Ta3N5, have small band gaps to respond to visible-light, whereas they can still realize overall solar water splitting with the proper positions of conduction band minimum and valence band maximum. This review describes recent progress regarding the improvement of photocatalytic activities of tantalum-based semiconductors. Basic concepts and principles of solar water splitting will be discussed in the introduction section, followed by the three main categories regarding to the different types of tantalum-based semiconductors. In each category, synthetic methodologies, influencing factors on the photocatalytic activities, strategies to enhance the efficiencies of photocatalysts and morphology control of tantalum-based materials will be discussed in detail. Future directions to further explore the research area of tantalum-based semiconductors for solar water splitting

  2. Dynamic Modeling of the Solar Field in Parabolic Trough Solar Power Plants

    Directory of Open Access Journals (Sweden)

    Lourdes A. Barcia

    2015-11-01

    Full Text Available Parabolic trough solar power plants use a thermal fluid to transfer thermal energy from solar radiation to a water-steam Rankine cycle in order to drive a turbine that, coupled to an electrical generator, produces electricity. These plants have a heat transfer fluid (HTF system with the necessary elements to transform solar radiation into heat and to transfer that thermal energy to the water-steam exchangers. In order to get the best possible performance in the Rankine cycle and, hence, in the thermal plant, it is necessary that the thermal fluid reach its maximum temperature when leaving the solar field (SF. Also, it is mandatory that the thermal fluid does not exceed the maximum operating temperature of the HTF, above which it degrades. It must be noted that the optimal temperature of the thermal fluid is difficult to obtain, since solar radiation can change abruptly from one moment to another. The aim of this document is to provide a model of an HTF system that can be used to optimize the control of the temperature of the fluid without interfering with the normal operation of the plant. The results obtained with this model will be contrasted with those obtained in a real plant.

  3. Solar Radiation Disinfection of Drinking Water at Temperate Latitudes: Inactivation rates for an optimized reactor configuration

    Science.gov (United States)

    Solar radiation-driven inactivation of bacteria, virus and protozoan pathogen models was quantified in simulated drinking water at a temperate latitude (34°S). The water was seeded with Enterococcus faecalis, Clostridium sporogenes spores, and P22 bacteriophage, each at ca 1 x 10...

  4. Extrapolating Solar Dynamo Models Throughout the Heliosphere

    Science.gov (United States)

    Cox, B. T.; Miesch, M. S.; Augustson, K.; Featherstone, N. A.

    2014-12-01

    There are multiple theories that aim to explain the behavior of the solar dynamo, and their associated models have been fiercely contested. The two prevailing theories investigated in this project are the Convective Dynamo model that arises from the pure solving of the magnetohydrodynamic equations, as well as the Babcock-Leighton model that relies on sunspot dissipation and reconnection. Recently, the supercomputer simulations CASH and BASH have formed models of the behavior of the Convective and Babcock-Leighton models, respectively, in the convective zone of the sun. These models show the behavior of the models within the sun, while much less is known about the effects these models may have further away from the solar surface. The goal of this work is to investigate any fundamental differences between the Convective and Babcock-Leighton models of the solar dynamo outside of the sun and extending into the solar system via the use of potential field source surface extrapolations implemented via python code that operates on data from CASH and BASH. The use of real solar data to visualize supergranular flow data in the BASH model is also used to learn more about the behavior of the Babcock-Leighton Dynamo. From the process of these extrapolations it has been determined that the Babcock-Leighton model, as represented by BASH, maintains complex magnetic fields much further into the heliosphere before reverting into a basic dipole field, providing 3D visualisations of the models distant from the sun.

  5. Development of heat pipes for solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Akyurt, M.

    1984-01-01

    Numerous heat pipes were designed, manufactured, and filled on a specially developed filling rig. Each heat pipe was incorporated into a prototype solar water heater developed for this purpose, and was tested under actual insolation conditions. An extensive testing program lasting for more than a year revealed that the heat pipes perform satisfactorily as heat transfer elements in solar water heaters. A special heat pipe featuring a compact and effective condenser configuration was also tested. It was observed to likewise exhibit isothermal behavior and hence promised potential for large scale solar applications.

  6. 24 CFR 200.950 - Building product standards and certification program for solar water heating system.

    Science.gov (United States)

    2010-04-01

    ... certification program for solar water heating system. 200.950 Section 200.950 Housing and Urban Development... solar water heating system. (a) Applicable standards. (1) All solar water heating systems shall be...) Document OG-300-93, Operating Guidelines and Minimum Standards for Certifying Solar Water Heating...

  7. Dynamo Models of the Solar Cycle

    Directory of Open Access Journals (Sweden)

    Charbonneau Paul

    2005-06-01

    Full Text Available This paper reviews recent advances and current debates in modeling the solar cycle as a hydromagnetic dynamo process. Emphasis is placed on (relatively simple dynamo models that are nonetheless detailed enough to be comparable to solar cycle observations. After a brief overview of the dynamo problem and of key observational constraints, we begin by reviewing the various magnetic field regeneration mechanisms that have been proposed in the solar context. We move on to a presentation and critical discussion of extant solar cycle models based on these mechanisms. We then turn to the origin of fluctuations in these models, including amplitude and parity modulation, chaotic behavior, and intermittency. The paper concludes with a discussion of our current state of ignorance regarding various key questions, the most pressing perhaps being the identification of the physical mechanism(s responsible for the generation of the Sun's poloidal magnetic field component.

  8. First solar models with OPAS opacity tables

    CERN Document Server

    Pennec, Maëlle Le; Salmon, Sébastien; Blancard, Christophe; Cossé, Philippe; Faussurier, Gérald; Mondet, Guillaume

    2015-01-01

    Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However the particular case of Sun is still challenging. The helioseismic sound speed determination continues to disagree with the Standard Solar Model (SSM) prediction for about a decade, questioning the reliability of this model. One of the sources of uncertainty could be in the treatment of the transport of radiation from the solar core to the surface. In this letter, we use the new OPAS opacity tables, recently available for solar modelling, to address this issue. We discuss first the peculiarities of these tables, then we quantify their impact on the solar sound speed and density profiles using the reduced OPAS tables taken on the grids of the OPAL ones. We use the two evolution codes MESA and CLES that led to similar conclusions in the solar radiative zone. In comparison to commonly used OPAL opacity tables, the new solar models computed, for the most recent photosphe...

  9. Solar and wind opportunities for water desalination in the Arab regions

    Energy Technology Data Exchange (ETDEWEB)

    Al-Karaghouli, Ali; Renne, David; Kazmerski, Lawrence L. [National Renewable Energy Laboratory, Golden, CO 80401 (United States)

    2009-12-15

    Despite the abundance of renewable energy resources in the Arab region, the use of solar thermal, solar photovoltaics, and wind is still in its technological and economic infancy. Great potential exists, but economic constraints have impeded more rapid growth for many applications. These technologies have certainly advanced technically over the last quarter century to the point where they should now be considered clean-energy alternatives to fossil fuels. For the Arab countries and many other regions of the world, potable water is becoming as critical a commodity as electricity. As renewable energy technologies advance and environmental concerns rise, these technologies are becoming more interesting partners for powering water desalination projects. We evaluate the current potential and viability of solar and wind, emphasizing the strict mandate for accurate, reliable site-specific resource data. Water desalination can be achieved through either thermal energy (using phase-change processes) or electricity (driving membrane processes), and these sources are best matched to the particular desalination technology. Desalination using solar thermal can be accomplished by multistage flash distillation, multi-effect distillation, vapor compression, freeze separation, and solar still methods. Concentrating solar power offers the best match to large-scale plants that require both high-temperature fluids and electricity. Solar and wind electricity can be effective energy sources for reverse osmosis, electrodialysis, and ultra- and nano-filtration. All these water desalination processes have special operational and high energy requirements that put additional requisites on the use of solar and wind to power these applications. We summarize the characteristics of the various desalination technologies. The effective match of solar thermal, solar photovoltaics, and wind to each of these is discussed in detail. An economic analysis is provided that incorporates energy consumption

  10. Solar models, neutrino experiments, and helioseismology

    Science.gov (United States)

    Bahcall, John N.; Ulrich, Roger K.

    1988-01-01

    The event rates and their recognized uncertainties are calculated for 11 solar neutrino experiments using accurate solar models. These models are also used to evaluate the frequency spectrum of the p and g oscillations modes of the sun. It is shown that the discrepancy between the predicted and observed event rates in the Cl-37 and Kamiokande II experiments cannot be explained by a 'likely' fluctuation in input parameters with the best estimates and uncertainties given in the present study. It is suggested that, whatever the correct solution to the solar neutrino problem, it is unlikely to be a 'trival' error.

  11. Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas

    Science.gov (United States)

    1980-01-01

    A solar heating on cooling system is described which is designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 solargenics, series 76, flat plate collectors with a total area of 1,596 square feet. The solar loop circulates an ethylene glyco water solution through the collectors into a hot water system exchanger. The water storage subsystem consists of a heat exchanger, two 2,300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water water fixtures. The building cold water system provides make up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described.

  12. A New Generation of Standard Solar Models

    Science.gov (United States)

    Vinyoles, Núria; Serenelli, Aldo M.; Villante, Francesco L.; Basu, Sarbani; Bergström, Johannes; Gonzalez-Garcia, M. C.; Maltoni, Michele; Peña-Garay, Carlos; Song, Ningqiang

    2017-02-01

    We compute a new generation of standard solar models (SSMs) that includes recent updates on some important nuclear reaction rates and a more consistent treatment of the equation of state. Models also include a novel and flexible treatment of opacity uncertainties based on opacity kernels, required in light of recent theoretical and experimental works on radiative opacity. Two large sets of SSMs, each based on a different canonical set of solar abundances with high and low metallicity (Z), are computed to determine model uncertainties and correlations among different observables. We present detailed comparisons of high- and low-Z models against different ensembles of solar observables, including solar neutrinos, surface helium abundance, depth of the convective envelope, and sound speed profile. A global comparison, including all observables, yields a p-value of 2.7σ for the high-Z model and 4.7σ for the low-Z one. When the sound speed differences in the narrow region of 0.65< r/{R}ȯ < 0.70 are excluded from the analysis, results are 0.9σ and 3.0σ for high- and low-Z models respectively. These results show that high-Z models agree well with solar data but have a systematic problem right below the bottom of the convective envelope linked to steepness of molecular weight and temperature gradients, and that low-Z models lead to a much more general disagreement with solar data. We also show that, while simple parametrizations of opacity uncertainties can strongly alleviate the solar abundance problem, they are insufficient to substantially improve the agreement of SSMs with helioseismic data beyond that obtained for high-Z models due to the intrinsic correlations of theoretical predictions.

  13. UV-A (315-400 nm) irradiance from measurements at 380 nm for solar water treatment and disinfection. Comparison between model and measurements in Buenos Aires, Argentina and Almeria, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Navntoft, C.; Dawidowski, L. [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, B1650KNA San Martin (Argentina)]|[Escuela de Posgrado, Universidad Nacional de San Martin, Peatonal Belgrano 3563, B1650ANQ San Martin (Argentina); Blesa, M.A. [Unidad de Actividad Quimica, Comision Nacional de Energia Atomica, Av. Gral Paz 1499, B1650KNA San Martin (Argentina)]|[Escuela de Posgrado, Universidad Nacional de San Martin, Peatonal Belgrano 3563, B1650ANQ San Martin (Argentina)]|[Consejo Nacional de investigaciones Cientificas y Tecnicas (CONICET), Av. Rivadavia 1917, C1033AAJ Ciudad de Buenos Aires (Argentina); Fernandez-Ibanez, P. [Plataforma Solar de Almeria, Carretera Senes km 4, 04002 Tabernas (Spain); Wolfram, E.A. [Centro de Investigaciones Cientificas y Tecnicas de las Fuerzas Armadas (CITEFA), San Juan Bautista de La Salle 4397, B1603ALO Villa Martelli (Argentina); Paladini, A. [Instituto de Genetica y Biologia Molecular, Vuelta de Obligado 2490, CP 1428, Ciudad de Buenos Aires (Argentina)]|[Consejo Nacional de investigaciones Cientificas y Tecnicas (CONICET), Av. Rivadavia 1917, C1033AAJ Ciudad de Buenos Aires (Argentina)

    2009-02-15

    A linear correlation between UV-A and 380 nm was developed by means of the TUV 4.1 radiative transfer model. The prediction error of the correlation was evaluated with data from Buenos Aires, Argentina, 2001, and from 2006, Almeria, Spain. Percent random mean square error (RMSE%) was calculated for intervals of 10 of solar zenith angles, ranging 4.75% at 20 to 37.70% at 90 in clear days and 22.16% at 20 to 26.17% at 90 for cloudy days in Buenos Aires Argentina, and 1.27% at 20 to 11.27% at 90 for clear days in Almeria, Spain. Clouded days were not assessed with the data from Spain. In Argentina, the UV-A radiometer is located in a rural area and the 380 nm radiometer is located in an urban area 6 km away. Hence the real error of the proposed model is closer to that found in Spain were both measurements were performed at the same site. The objective of the work is to achieve a simple and precise method to assess UV-A availability for environmental applications of solar energy, particularly for solar water treatment, at any desired latitude. (author)

  14. Water disinfection by solar photocatalysis using compound parabolic collectors

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, P.; Blanco, J.; Sichel, C.; Malato, S. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Plataforma Solar de Almeria (PSA), P.O. Box 22, 04200 Tabernas, Almeria (Spain)

    2005-04-15

    TiO{sub 2} solar photocatalysis has been proven to be a degradation process for aqueous organic contaminant leading to total mineralisation of a large number of compounds. Furthermore, the interest in using this technique for water disinfection has grown in the last decade. Recent publications have reported photokilling of bacteria and viruses by TiO{sub 2} photocatalysis. Therefore, solar photocatalysis disinfection seems to be a very promising process, which could help to improve public health in rural areas of developing countries. The objective of this work was to assess the feasibility of using TiO{sub 2} solar photocatalysis to disinfect water supplies for future applications in developing countries. This article reviews the viability of solar photocatalysis for disinfection in low cost compound parabolic collectors, using sunlight and titanium dioxide semiconductor, both applied as slurry and supported. We report on the bactericidal action of TiO{sub 2} on a pure culture of Escherichia coli with a low cost photoreactor based on compound parabolic collectors. The influence of different experimental set-ups and parameters are also analysed. The results and potential application of the solar photocatalysis technology to water disinfection are studied within the frame of two research EU projects whose objective consist on the development of a fully autonomous solar reactor system to purify drinking water in remote locations of developing countries.

  15. Hail risk model for solar collectors

    Science.gov (United States)

    Gonzalez, C.

    1978-01-01

    This report presents the results of a study assessing the probability of solar arrays being struck by hailstones of various sizes as a function of geographic location and service life. The study complements parallel studies of solar array sensitivity to hail damage, the final objective being an estimate of the most cost effective level for solar array hail protection. A key element of this study involves the generation of a statistical model describing the probability of impact by hailstones of various sizes and estimating the mean time between hits.

  16. Performance of Thermosyphon Solar Water Heaters in Series

    Directory of Open Access Journals (Sweden)

    Tsong-Sheng Lee

    2012-08-01

    Full Text Available More than a single thermosyphon solar water heater may be employed in applications when considerable hot water consumption is required. In this experimental investigation, eight typical Taiwanese solar water heaters were connected in series. Degree of temperature stratification and thermosyphon flow rate in a horizontal tank were evaluated. The system was tested under no-load, intermittent and continuous load conditions. Results showed that there was stratification in tanks under the no-load condition. Temperature stratification also redeveloped after the draw-off. Analysis of thermal performance of the system was conducted for each condition.

  17. Poly 3-Hexylthiophene as a photocathode for solar water splitting

    OpenAIRE

    Suppes, Graeme McCallum

    2015-01-01

    The focus of this research is to determine the extent to which poly 3-hexylthiophene (P3HT) can be used as a photoelectrode for solar water splitting. Research in the area of solar water splitting mostly focuses on inorganic materials but conjugated polymers, such as P3HT, offer several advantages. Most metal oxides used as photoelectrodes are only able to carry out water oxidation, require thick films to absorb significant amounts of light, and absorb light mainly in the ultraviolet part of ...

  18. Two different sources of water for the early solar nebula.

    Science.gov (United States)

    Kupper, Stefan; Tornow, Carmen; Gast, Philipp

    2012-06-01

    Water is essential for life. This is a trivial fact but has profound implications since the forming of life on the early Earth required water. The sources of water and the related amount of delivery depend not only on the conditions on the early Earth itself but also on the evolutionary history of the solar system. Thus we ask where and when water formed in the solar nebula-the precursor of the solar system. In this paper we explore the chemical mechanics for water formation and its expected abundance. This is achieved by studying the parental cloud core of the solar nebula and its gravitational collapse. We have identified two different sources of water for the region of Earth's accretion. The first being the sublimation of the icy mantles of dust grains formed in the parental cloud. The second source is located in the inner region of the collapsing cloud core - the so-called hot corino with a temperature of several hundred Kelvin. There, water is produced efficiently in the gas phase by reactions between neutral molecules. Additionally, we analyse the dependence of the production of water on the initial abundance ratio between carbon and oxygen.

  19. Design package for solar domestic hot water system

    Science.gov (United States)

    1980-01-01

    The initial design of a solar domestic hot water system is considered. The system performance specification and detailed design drawings are included. The hot water systems consist of the following subsystems: collector, storage, control, transport, auxiliary energy, and government-furnished site data acquisition. The two systems are installed at Tempe, Arizona, and San Diego, California.

  20. Nanoflare heating model for collisionless solar corona

    Indian Academy of Sciences (India)

    U L VISAKH KUMAR; BILIN SUSAN VARGHESE; P J KURIAN

    2017-02-01

    The problem of coronal heating remains one of the greatest unresolved problems in space science. Magnetic reconnection plays a significant role in heating the solar corona. When two oppositely directed magnetic fields come closer to form a current sheet, the current density of the plasma increases due to which magnetic reconnection and conversion of magnetic energy into thermal energy takes place. The present paper deals with a model for reconnection occurring in the solar corona under steady state in collisionless regime. The model predicts that reconnection time in the solar corona varies inversely with the cube of magnetic field and varies directly with the Lindquist number. Our analysis shows that reconnections are occurring within a time interval of600 s in the solar corona, producing nanoflares in the energy range $10^{21}–10^{23}$ erg/s which matches with Yohkoh X-ray observations.

  1. Nanoflare heating model for collisionless solar corona

    Science.gov (United States)

    Visakh Kumar, U. L.; Varghese, Bilin Susan; Kurian, P. J.

    2017-02-01

    The problem of coronal heating remains one of the greatest unresolved problems in space science. Magnetic reconnection plays a significant role in heating the solar corona. When two oppositely directed magnetic fields come closer to form a current sheet, the current density of the plasma increases due to which magnetic reconnection and conversion of magnetic energy into thermal energy takes place. The present paper deals with a model for reconnection occurring in the solar corona under steady state in collisionless regime. The model predicts that reconnection time in the solar corona varies inversely with the cube of magnetic field and varies directly with the Lindquist number. Our analysis shows that reconnections are occurring within a time interval of 600 s in the solar corona, producing nanoflares in the energy range 10 21-10 23 erg /s which matches with Yohkoh X-ray observations.

  2. Installation package for a domestic solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    The installation of two prototype solar heating and hot water systems is described. The systems consists of the following subsystems: solar collector, storage, control, transport, and auxiliary energy.

  3. Validation, Optimization and Simulation of a Solar Thermoelectric Generator Model

    Science.gov (United States)

    Madkhali, Hadi Ali; Hamil, Ali; Lee, HoSung

    2017-08-01

    This study explores thermoelectrics as a viable option for small-scale solar thermal applications. Thermoelectric technology is based on the Seebeck effect, which states that a voltage is induced when a temperature gradient is applied to the junctions of two differing materials. This research proposes to analyze, validate, simulate, and optimize a prototype solar thermoelectric generator (STEG) model in order to increase efficiency. The intent is to further develop STEGs as a viable and productive energy source that limits pollution and reduces the cost of energy production. An empirical study (Kraemer et al. in Nat Mater 10:532, 2011) on the solar thermoelectric generator reported a high efficiency performance of 4.6%. The system had a vacuum glass enclosure, a flat panel (absorber), thermoelectric generator and water circulation for the cold side. The theoretical and numerical approach of this current study validated the experimental results from Kraemer's study to a high degree. The numerical simulation process utilizes a two-stage approach in ANSYS software for Fluent and Thermal-Electric Systems. The solar load model technique uses solar radiation under AM 1.5G conditions in Fluent. This analytical model applies Dr. Ho Sung Lee's theory of optimal design to improve the performance of the STEG system by using dimensionless parameters. Applying this theory, using two cover glasses and radiation shields, the STEG model can achieve a highest efficiency of 7%.

  4. Water recovery in a concentrated solar power plant

    Science.gov (United States)

    Raza, Aikifa; Higgo, Alex R.; Alobaidli, Abdulaziz; Zhang, TieJun

    2016-05-01

    For CSP plants, water consumption is undergoing increasing scrutiny particularly in dry and arid regions with water scarcity conditions. Significant amount of water has to be used for parabolic trough mirror cleaning to maintain high mirror reflectance and optical efficiency in sandy environment. For this specific purpose, solar collectors are washed once or twice every week at Shams 1, one of the largest CSP plant in the Middle East, and about 5 million gallons of demineralized water is utilized every year without further recovery. The produced waste water from a CSP plant contains the soiling i.e. accumulated dust and some amount of organic contaminants, as indicated by our analysis of waste water samples from the solar field. We thus need to develop a membrane based system to filter fine dust particulates and to degrade organic contaminant simultaneously. Membrane filtration technology is considered to be cost-effective way to address the emerging problem of a clean water shortage, and to reuse the filtered water after cleaning solar collectors. But there are some major technical barriers to improve the robustness and energy efficiency of filtration membranes especially when dealing with the removal of ultra-small particles and oil traces. Herein, we proposed a robust and scalable nanostructured inorganic microporous filtration copper mesh. The inorganic membrane surface wettability is tailored to enhance the water permeability and filtration flux by creating nanostructures. These nanostructured membranes were successfully employed to recover water collected after cleaning the reflectors of solar field of Shams 1. Another achievement was to remove the traces of heat transfer fluid (HTF) from run-off water which was collected after accidental leakage in some of the heat exchangers during the commissioning of the Shams 1 for safe disposal into the main stream. We hope, by controlling the water recovery factor and membrane reusability performance, the membrane

  5. Using Solar Energy to Desalinate Water.

    Science.gov (United States)

    Tabor, Harry Z.

    1978-01-01

    Material presented is adapted from Desalination with Solar Energy, a paper presented before the International Symposium on Energy Sources and Development, held in Spain in 1977. Desalination systems energized by the sun, conditions governing their efficiency, and their costs are discussed. (HM)

  6. Solar hot water space heating system. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Van Dam, T

    1979-08-13

    A retrofit solar heating system was installed on Madison Hall at Jordan College, Cedar Springs, Michigan. The system provides heating and domestic water preheating for a campus dormitory. Freeze protection is provided by a draindown system. The building and solar system, construction progress, and design changes are described. Included in appendices are: condensate trap design, structural analysis, pictures of installation, operating instructions, maintenance instructions, and as-built drawings. (MHR)

  7. Solar hot water systems for the southeastern United States: principles and construction of breadbox water heaters

    Energy Technology Data Exchange (ETDEWEB)

    None

    1983-02-01

    The use of solar energy to provide hot water is among the easier solar technologies for homeowners to utilize. In the Southeastern United States, because of the mild climate and abundant sunshine, solar energy can be harnessed to provide a household's hot water needs during the non-freezing weather period mid-April and mid-October. This workbook contains detailed plans for building breadbox solar water heaters that can provide up to 65% of your hot water needs during warm weather. If fuel costs continue to rise, the annual savings obtained from a solar water heater will grow dramatically. The designs in this workbook use readily available materials and the construction costs are low. Although these designs may not be as efficient as some commercially available systems, most of a household's hot water needs can be met with them. The description of the breadbox water heater and other types of solar systems will help you make an informed decision between constructing a solar water heater or purchasing one. This workbook is intended for use in the southeastern United States and the designs may not be suitable for use in colder climates.

  8. Cyprus solar water heating cluster: A missed opportunity?

    Energy Technology Data Exchange (ETDEWEB)

    Maxoulis, Christos N. [Cyprus Organisation for Standardisation (CYS) (Cyprus); Cyprus International Institute of Management (CIIM) (Cyprus); Charalampous, Harris P. [Cyprus International Institute of Management (CIIM) (Cyprus); Kalogirou, Soteris A. [Higher Technical Institute, P.O. Box 20423, Nicosia 2152 (Cyprus)]. E-mail: Skalogir@spidernet.com.cy

    2007-06-15

    Cyprus is often called the 'sun island' because of the amount of sunshine received all year round. The abundance of solar radiation together with a good technological base has created favourable conditions for the exploitation of solar energy on the island. This led to the development of a pioneering solar collector industry in Cyprus, which in the mid-1980s was flourishing. The result was an outstanding figure of installed solar collector area per inhabitant. Nowadays, Cyprus is cited as the country with the highest solar collector area installed per inhabitant, worldwide. This means that the local market for solar thermal collectors (for domestic applications) is now rather saturated. It was only rational to assume that Cypriot firms equipped with their gained expertise and leading edge would have safeguarded a sustainable growth and have an international orientation, focusing on exports in an emerging European and eastern Mediterranean thermal solar market. Unfortunately, this is not the case today. This paper reviews the economic performance and the competitiveness of Cyprus and the evolution of the solar water heating (SWH) industry using the cluster theory of Michael Porter. Its aim is to give insight and explanations for the success of the sector domestically, its failure with regards to exporting activity, pinpoint the industry in the European map and finally give recommendations for the cross the boarders commercial success of the industry.

  9. A modular solar system provides hot water for alligator farm

    Energy Technology Data Exchange (ETDEWEB)

    Healey, H.M. (Healey Associates, Merritt Island, FL (United States))

    1994-03-01

    This article describes an 8,000 ft[sup 2] (743 m[sup 2]), site-built, large volume, Integral Collector Storage (ICS) solar water heating system installed at the farm to preheat water for the building washdown as part of a Florida Energy Office demonstration project. The project utilized at Foster Farms was a Shallow Solar Pond (SSP)--a modular, site-built, solar water heating system capable of providing in excess of 5,000 heated gallons (19 m[sup 3]) per day. During the past 10 years, a large number of solar systems have been proposed to provide economical hot water for industrial processes. Most of these water heating systems have proven to be too costly or too complex to compete with the traditional water heating methods using conventional fuels. Technology initiated at Lawrence Livermore Laboratory and expanded upon by the Tennessee Valley Authority was shown to have outstanding potential in Florida. This technology, which was utilized at Foster Farms, consists of a site-built large-volume ICAS system called the Shallow Solar Pond. Shallow Solar Pond (SSP) systems utilize the modular approach in which modules, built in a standardized size, are tied together to supply the required load. The SSP module can be ground mounted or installed on a roof. Each SSP module is typically 16 ft (5 m) wide and up to 200 ft (61 m) in length. The module contains one or two flat waterbags similar to a waterbed. The bags rest on a layer of insulation or bed of sand inside concrete or fiberglass curbs. The bag is protected against damage and heat loss by greenhouse-type glazing. A typical 200 ft [times] 16 ft (61 m [times] 5 m) pond, filled to a 4 in. (10 cm) depth, holds approximately 8,000 gallons (30 m[sup 3]) of water.

  10. Comparison of Columnar Water-Vapor Measurements from Solar Transmittance Methods

    Science.gov (United States)

    Schmid, Beat; Michalsky, J.; Slater, Donald W.; Barnard, James C.; Halthore, Rangasayi N.; Liljegren, James C.; Holben, Brent N.; Eck, Thomas F.; Livingston, John M.; Russell, Philp B.

    2001-01-01

    The Atmospheric Radiation Measurement program studied water vapor abundance measurement at its southern Great Plains site in the fall of 1997. The program used a large number of instruments, including four solar radiometers. By measuring solar transmittance in the 0.94 micrometer water apor absorption band, they were able to measure columnar water vapor (CWV). In the second round of comparison we used the same radiative transfer model, and the same line-by-line code (which includes recently corrected H2O spectroscopy) to retrieve CWV from all four solar radiometers, thus decreasing the mean CWV by 8 - 13 %. The model was not responsible for the 8 % spread in CWV which remained.

  11. Solar energy estimation using REST2 model

    Directory of Open Access Journals (Sweden)

    M. Rizwan, Majid Jamil, D. P. Kothari

    2010-03-01

    Full Text Available The network of solar energy measuring stations is relatively rare through out the world. In India, only IMD (India Meteorological Department Pune provides data for quite few stations, which is considered as the base data for research purposes. However, hourly data of measured energy is not available, even for those stations where measurement has already been done. Due to lack of hourly measured data, the estimation of solar energy at the earth’s surface is required. In the proposed study, hourly solar energy is estimated at four important Indian stations namely New Delhi, Mumbai, Pune and Jaipur keeping in mind their different climatic conditions. For this study, REST2 (Reference Evaluation of Solar Transmittance, 2 bands, a high performance parametric model for the estimation of solar energy is used. REST2 derivation uses the two-band scheme as used in the CPCR2 (Code for Physical Computation of Radiation, 2 bands but CPCR2 does not include NO2 absorption, which is an important parameter for estimating solar energy. In this study, using ground measurements during 1986-2000 as reference, a MATLAB program is written to evaluate the performance of REST2 model at four proposed stations. The solar energy at four stations throughout the year is estimated and compared with CPCR2. The results obtained from REST2 model show the good agreement against the measured data on horizontal surface. The study reveals that REST2 models performs better and evaluate the best results as compared to the other existing models under cloudless sky for Indian climatic conditions.

  12. Application of Solar Photovoltaic Water Pumping System in Hainan Agriculture

    Institute of Scientific and Technical Information of China (English)

    Xiangchun; YU; Qingqing; LIN; Xuedong; ZHOU; Zhibin; YANG

    2013-01-01

    With radical socio-economic development and strengthening of regulation of agricultural industrial structure in Hainan Province,fresh water resource becomes increasingly insufficient.Existing water-saving facilities and measures are unable to promote sustainable and stable development of local economy.This needs modern irrigation method.Solar photovoltaic water pumping system is necessary and feasible in Hainan agriculture,and will have directive significance for Hainan Province developing photovoltaic agriculture.

  13. Optical models for silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, T.; Sopori, B. [National Renewable Energy Lab., Golden, CO (United States)

    1995-08-01

    Light trapping is an important design feature for high-efficiency silicon solar cells. Because light trapping can considerably enhance optical absorption, a thinner substrate can be used which, in turn, can lower the bulk carrier recombination and concommitantly increase open-circuit voltage, and fill factor of the cell. The basic concepts of light trapping are similar to that of excitation of an optical waveguide, where a prism or a grating structure increases the phase velocity of the incoming optical wave such that waves propagated within the waveguide are totally reflected at the interfaces. Unfortunately, these concepts break down because the entire solar cell is covered with such a structure, making it necessary to develop new analytical approaches to deal with incomplete light trapping in solar cells. This paper describes two models that analyze light trapping in thick and thin solar cells.

  14. Solar Fuels: Photocatalytic Water Splitting Using a 2‐Photon Approach

    DEFF Research Database (Denmark)

    Seger, Brian; Mei, Bastian Timo; Bae, Dowon;

    2014-01-01

    energyphotons while the other absorbs the low energy photons. This is demonstrated in Figure 1A. While theconcept seems relatively simple, no one has yet been able to full optimize this system.2‐photon water splitting devices have many issues that need to be optimized. Both solar cells needto be optimized......While the sun provides orders of magnitude more energy than we consume on earth, it is intermittent, and thus we must have storage reservoirs for when it is dark. Plants have realized early on that storing this energy in the form of molecular fuels is quite effective. In our work, we take...... a similarapproach and look to use solar cells to electrolyze water into hydrogen fuel and an oxygen byproduct. Modelling has shown that to optimize photoelectrolysis efficiency, a 2 photon tandem device (back toback solar cells) should be used. The underlying principle is that one solar cell should absorb high...

  15. Solar hot water demonstration project at Red Star Industrial Laundry, Fresno, California

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    The Final Report of the Solar Hot Water System located at the Red Star Industrial Laundry, 3333 Sabre Avenue, Fresno, California, is presented. The system was designed as an integrated wastewater heat recovery and solar preheating system to supply a part of the hot water requirements. It was estimated that the natural gas demand for hot water heating could be reduced by 56 percent (44 percent heat reclamation and 12 percent solar). The system consists of a 16,500 gallon tube-and-shell wastewater heat recovery subsystem combined with a pass-through 6,528 square foot flat plate Ying Manufacturing Company Model SP4120 solar collector subsystem, a 12,500 gallon fiber glass water storage tank subsystem, pumps, heat exchangers, controls, and associated plumbing. The design output of the solar subsystem is approximately 2.6 x 10/sup 9/ Btu/year. Auxiliary energy is provided by a gas fired low pressure boiler servicing a 4,000 gallon service tank. This project is part of the US Department of Energy's Solar Demonstration Program with DOE sharing $184,841 of the $260,693 construction cost. The system was turned on in July 1977, and acceptance tests completed in September 1977. The demonstration period for this project ends September 2, 1982.

  16. Photocatalytic Enhancement for Solar Disinfection of Water: A Review

    Directory of Open Access Journals (Sweden)

    J. Anthony Byrne

    2011-01-01

    Full Text Available It is estimated that 884 million people lack access to improved water supplies. Many more are forced to rely on supplies that are microbiologically unsafe, resulting in a higher risk of waterborne diseases, including typhoid, hepatitis, polio, and cholera. Due to poor sanitation and lack of clean drinking water, there are around 4 billion cases of diarrhea each year resulting in 2.2 million deaths, most of these are children under five. While conventional interventions to improve water supplies are effective, there is increasing interest in household-based interventions to produce safe drinking water at an affordable cost for developing regions. Solar disinfection (SODIS is a simple and low cost technique used to disinfect drinking water, where water is placed in transparent containers and exposed to sunlight for 6 hours. There are a number of parameters which affect the efficacy of SODIS, including the solar irradiance, the quality of the water, and the nature of the contamination. One approach to SODIS enhancement is the use of semiconductor photocatalysis to produce highly reactive species that can destroy organic pollutants and inactivate water pathogens. This paper presents a critical review concerning semiconductor photocatalysis as a potential enhancement technology for solar disinfection of water.

  17. Potential of Using Solar Energy for Drinking Water Treatment Plant

    Science.gov (United States)

    Bukhary, S. S.; Batista, J.; Ahmad, S.

    2016-12-01

    Where water is essential to energy generation, energy usage is integral to life cycle processes of water extraction, treatment, distribution and disposal. Increasing population, climate change and greenhouse gas production challenges the water industry for energy conservation of the various water-related operations as well as limiting the associated carbon emissions. One of the ways to accomplish this is by incorporating renewable energy into the water sector. Treatment of drinking water, an important part of water life cycle processes, is vital for the health of any community. This study explores the feasibility of using solar energy for a drinking water treatment plant (DWTP) with the long-term goal of energy independence and sustainability. A 10 MGD groundwater DWTP in southwestern US was selected, using the treatment processes of coagulation, filtration and chlorination. Energy consumption in units of kWh/day and kWh/MG for each unit process was separately determined using industry accepted design criteria. Associated carbon emissions were evaluated in units of CO2 eq/MG. Based on the energy consumption and the existing real estate holdings, the DWTP was sized for distributed solar. Results showed that overall the motors used to operate the pumps including the groundwater intake pumps were the largest consumers of energy. Enough land was available around DWTP to deploy distributed solar. Results also showed that solar photovoltaics could potentially be used to meet the energy demands of the selected DWTP, but warrant the use of a large storage capacity, and thus increased costs. Carbon emissions related to solar based design were negligible compared to the original case. For future, this study can be used to analyze unit processes of other DWTP based on energy consumption, as well as for incorporating sustainability into the DWTP design.

  18. Solar heating and hot water system installed at Listerhill, Alabama

    Science.gov (United States)

    1978-01-01

    The Solar system was installed into a new building and was designed to provide 79% of the estimated annual space heating load and 59% of the estimated annual potable hot water requirement. The collectors are flat plate, liquid manufactured by Reynolds Metals Company and cover a total area of 2344 square feet. The storage medium is water inhibited with NALCO 2755 and the container is an underground, unpressurized steel tank with a capacity of 5000 gallons. This report describes in considerable detail the solar heating facility and contains detailed drawings of the completed system.

  19. Solar heating and hot water system installed at Listerhill, Alabama

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    The solar system was installed into a new buildng and was designed to provide 79% of the estimated annual space heating load and 59% of the estimated annual potable hot water requirement. The collectors are flat plate, liquid manufactured by Reynolds Metals Company and cover a total area of 2344 square feet. The storage medium is water inhibited with NALCO 2755 and the container is an underground, unpressurized steel tank with a capacity of 5000 gallons. This final report describes in considerable detail the solar heating facility and contains detailed drawings of the completed system.

  20. Solar heating and hot water system installed at Listerhill, Alabama

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    The solar system was installed into a new buildng and was designed to provide 79% of the estimated annual space heating load and 59% of the estimated annual potable hot water requirement. The collectors are flat plate, liquid manufactured by Reynolds Metals Company and cover a total area of 2344 square feet. The storage medium is water inhibited with NALCO 2755 and the container is an underground, unpressurized steel tank with a capacity of 5000 gallons. This final report describes in considerable detail the solar heating facility and contains detailed drawings of the completed system.

  1. Innovative Sustainable Water Management Practices in Solar Residential Design

    Directory of Open Access Journals (Sweden)

    C. Jason Mabry

    2012-11-01

    Full Text Available This paper communicates the results of an architectural research project which sought innovative design strategies for achieving energy and resource efficiencies in water management systems traditionally used in single-family housing. It describes the engineering of an efficient, multifaceted, and fully integrated water management system for a domesticenvironment of 800 sq. ft., entirely powered by solar energy. The four innovations whose details are conveyed include the use of alternate materials for piping distribution and collection, the use of water in solar energy generation, the design of a building skin which capitalizes on water’s capacity to store heat as well as the design of a ecological groundscape which re-usesand filters waste water and rain water.Keywords: energy, plumbing, home design

  2. Low-Cost Solar Water Heating Research and Development Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Hudon, K.; Merrigan, T.; Burch, J.; Maguire, J.

    2012-08-01

    The market environment for solar water heating technology has changed substantially with the successful introduction of heat pump water heaters (HPWHs). The addition of this energy-efficient technology to the market increases direct competition with solar water heaters (SWHs) for available energy savings. It is therefore essential to understand which segment of the market is best suited for HPWHs and focus the development of innovative, low-cost SWHs in the market segment where the largest opportunities exist. To evaluate cost and performance tradeoffs between high performance hot water heating systems, annual energy simulations were run using the program, TRNSYS, and analysis was performed to compare the energy savings associated with HPWH and SWH technologies to conventional methods of water heating.

  3. More solar models and neutrino fluxes.

    Science.gov (United States)

    Abraham, Z.; Iben, I., Jr.

    1971-01-01

    Derivation of neutrino fluxes from a sequence of solar models that differ from one another in regard to opacity, equation of state, and nuclear cross-section factors. Using current estimates of the relevant input parameters, capture rates are obtained that range between three and ten times the most recent result of the Davis Cl 37 neutrino-capture experiment. The contribution to a theoretical capture rate due to neutrinos from all reactions other than B 8 decay ranges from 0.5 to 1.5 times the latest observational result. Comparison with results of other solar model calculations indicates reasonable agreement when results are normalized to the same input parameters.

  4. EPANET water quality model

    Energy Technology Data Exchange (ETDEWEB)

    Rossman, L.A.

    1993-01-01

    EPANET represents a third generation of water quality modeling software developed by the U.S. EPA's Drinking Water Research Division, offering significant advances in the state of the art for network water quality analysis. EPANET performs extended period simulation of hydraulic and water quality behavior within water distribution systems. In addition to substance concentration, water age and source tracing can also be simulated. EPANET includes a full featured hydraulic simulation model that can handle various types of pumps, valves, and their control rules. The water quality module is equipped to handle constituent reactions within the bulk pipe flow and at the pipe wall. It also features an efficient computational scheme that automatically determines optimal time steps and pipe segmentation for accurate tracking of material transport over time. EPANET is currently being used in the US to study such issues as loss of chlorine residual, source blending and trihalomethane (THM) formation, how altered tank operation affects water age, and total dissolved solids (TDS) control for an irrigation network.

  5. Stream Water Quality Model

    Data.gov (United States)

    U.S. Environmental Protection Agency — QUAL2K (or Q2K) is a river and stream water quality model that is intended to represent a modernized version of the QUAL2E (or Q2E) model (Brown and Barnwell 1987).

  6. Solar hot water system installed at Days Inn Motel, Dallas, Texas

    Energy Technology Data Exchange (ETDEWEB)

    1980-09-01

    The solar energy hot water system installed in the Days Inn of America, Inc., Days Inn Motel (100 rooms), I-635/2753 Forrest Lane, Dallas, Texas is described. The solar system was designed by ILI, Inc., to provide 65% of the total Domestic Hot Water (DHW) demand. The liquid flat plate (water) collector is 1000 square feet of solar energy products, Model CU-30W array. Water in the collector system automatically drains into the 1000 gallon steel storage tank located in the mechanical room when the pump is not running. Heat is transferred from the storage tank to DHW tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and the heat exchanger enables solar heated water to help make up DHW tank standby losses. All pumps are controlled by differential temperature. Operation of this system was begun March 11, 1980. The solar components were partly funded ($15,000 of $30,000 cost) by the Department of Energy Grant.

  7. Solar hot water system installed at Days Inn Motel, Jacksonville, Florida

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    The solar energy hot water system installed in the Days Inns of America, Inc., Days Inn Motel (120 rooms) I-95 and Cagle Road, Jacksonville, Florida, is described. The solar system was designed by ILI, Incorporated to provide 65 percent of the hot water demand. The system is one of eleven systems planned under this grant. Water (in the Solar Energy Products, Model CU-30ww liquid flat plate collector (900 square feet) system) automatically drains into the 1000 gallon lined and vented steel storage tank when the pump is not running. Heat is transferred from storage to Domestic Hot Water (DHW) tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up DHW standby losses. All pumps are controlled by differential temperature. This system was turned on June 19, 1979. The solar components were partly funded ($15,823 of $31,823 cost) by the Department of Energy.

  8. Retrofitting Domestic Hot Water Heaters for Solar Water Heating Systems in Single-Family Houses in a Cold Climate: A Theoretical Analysis

    Directory of Open Access Journals (Sweden)

    Björn Karlsson

    2012-10-01

    Full Text Available One of the biggest obstacles to economic profitability of solar water heating systems is the investment cost. Retrofitting existing domestic hot water heaters when a new solar hot water system is installed can reduce both the installation and material costs. In this study, retrofitting existing water heaters for solar water heating systems in Swedish single-family houses was theoretically investigated using the TRNSYS software. Four simulation models using forced circulation flow with different system configurations and control strategies were simulated and analysed in the study. A comparison with a standard solar thermal system was also presented based on the annual solar fraction. The simulation results indicate that the retrofitting configuration achieving the highest annual performance consists of a system where the existing tank is used as storage for the solar heat and a smaller tank with a heater is added in series to make sure that the required outlet temperature can be met. An external heat exchanger is used between the collector circuit and the existing tank. For this retrofitted system an annual solar fraction of 50.5% was achieved. A conventional solar thermal system using a standard solar tank achieves a comparable performance for the same total storage volume, collector area and reference conditions.

  9. Global MHD Models of the Solar Corona

    Science.gov (United States)

    Suess, S. T.; Rose, Franklin (Technical Monitor)

    2001-01-01

    Global magnetohydrodynamic (MHD) models of the solar corona are computationally intensive, numerically complex simulations that have produced important new results over the past few years. After a brief overview of how these models usually work, I will address three topics: (1) How these models are now routinely used to predict the morphology of the corona and analyze Earth and space-based remote observations of the Sun; (2) The direct application of these models to the analysis of physical processes in the corona and chromosphere and to the interpretation of in situ solar wind observations; and (3) The use of results from global models to validate the approximations used to make detailed studies of physical processes in the corona that are not otherwise possible using the global models themselves.

  10. Solar hot water system installed at Day's Lodge, Atlanta, Georgia

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    The solar energy hot water system installed in the Days Inns of America, Inc., Day's Lodge I-85 and Shallowford Road, NE Atlanta, Georgia is described. This system is one of eleven systems planned under this grant and was designed to provide for 81% of the total hot water demand. There are two separate systems, each serving one building of the lodge (total of 65 suites). The entire system contains only potable city water. The 1024 square feet of Grumman Sunstream Model 332 liquid flat plate collectors and the outside piping drains whenever the collector plates approach freezing or when power is interrupted. Solar heated water from the two above ground cement lined steel tanks (1000 gallon tank) is drawn into the electric domestic hot water (DHW) tanks as hot water is drawn. Electric resistance units in the DHW tanks top off the solar heated water, if needed, to reach thermostat setting. Operation of this system was begun in August, 1979. The solar components were partly funded ($18,042 of $36,084 cost) by the Department of Energy.

  11. A new Generation of Standard Solar Models

    CERN Document Server

    Vinyoles, Núria; Villante, Francesco L; Basu, Sarbani; Bergström, Johannes; Gonzalez-Garcia, M C; Maltoni, Michele; Peña-Garay, Carlos; Song, Ningqiang

    2016-01-01

    We compute a new generation of standard solar models (SSMs) that includes recent updates on some important nuclear reaction rates and a more consistent treatment of the equation of state. Models also include a novel and flexible treatment of opacity uncertainties based on opacity kernels, required in the light of recent theoretical and experimental works on radiative opacity. Two large sets of SSMs, each based on a different canonical set of solar abundances with high and low metallicity (Z), are computed to determine model uncertainties and correlations among different observables. We present detailed comparisons of high- and low-Z models against different ensembles of solar observables including solar neutrinos, surface helium abundance, depth of convective envelope and sound speed profile. A global comparison, including all observables, yields a p-value of 2.7$\\sigma$ for the high-Z model and 4.7$\\sigma$ for the low-Z one. When the sound-speed differences in the narrow region of $0.65 < r/R_{sun} < 0...

  12. Electric solar wind sail mass budget model

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2013-02-01

    Full Text Available The electric solar wind sail (E-sail is a new type of propellantless propulsion system for Solar System transportation, which uses the natural solar wind to produce spacecraft propulsion. The E-sail consists of thin centrifugally stretched tethers that are kept charged by an onboard electron gun and, as such, experience Coulomb drag through the high-speed solar wind plasma stream. This paper discusses a mass breakdown and a performance model for an E-sail spacecraft that hosts a mission-specific payload of prescribed mass. In particular, the model is able to estimate the total spacecraft mass and its propulsive acceleration as a function of various design parameters such as the number of tethers and their length. A number of subsystem masses are calculated assuming existing or near-term E-sail technology. In light of the obtained performance estimates, an E-sail represents a promising propulsion system for a variety of transportation needs in the Solar System.

  13. Federal technology alert. Parabolic-trough solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    Parabolic-trough solar water heating is a well-proven renewable energy technology with considerable potential for application at Federal facilities. For the US, parabolic-trough water-heating systems are most cost effective in the Southwest where direct solar radiation is high. Jails, hospitals, barracks, and other facilities that consistently use large volumes of hot water are particularly good candidates, as are facilities with central plants for district heating. As with any renewable energy or energy efficiency technology requiring significant initial capital investment, the primary condition that will make a parabolic-trough system economically viable is if it is replacing expensive conventional water heating. In combination with absorption cooling systems, parabolic-trough collectors can also be used for air-conditioning. Industrial Solar Technology (IST) of Golden, Colorado, is the sole current manufacturer of parabolic-trough solar water heating systems. IST has an Indefinite Delivery/Indefinite Quantity (IDIQ) contract with the Federal Energy Management Program (FEMP) of the US Department of Energy (DOE) to finance and install parabolic-trough solar water heating on an Energy Savings Performance Contract (ESPC) basis for any Federal facility that requests it and for which it proves viable. For an ESPC project, the facility does not pay for design, capital equipment, or installation. Instead, it pays only for guaranteed energy savings. Preparing and implementing delivery or task orders against the IDIQ is much simpler than the standard procurement process. This Federal Technology Alert (FTA) of the New Technology Demonstration Program is one of a series of guides to renewable energy and new energy-efficient technologies.

  14. Solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen efficiency over 30.

    Science.gov (United States)

    Jia, Jieyang; Seitz, Linsey C; Benck, Jesse D; Huo, Yijie; Chen, Yusi; Ng, Jia Wei Desmond; Bilir, Taner; Harris, James S; Jaramillo, Thomas F

    2016-10-31

    Hydrogen production via electrochemical water splitting is a promising approach for storing solar energy. For this technology to be economically competitive, it is critical to develop water splitting systems with high solar-to-hydrogen (STH) efficiencies. Here we report a photovoltaic-electrolysis system with the highest STH efficiency for any water splitting technology to date, to the best of our knowledge. Our system consists of two polymer electrolyte membrane electrolysers in series with one InGaP/GaAs/GaInNAsSb triple-junction solar cell, which produces a large-enough voltage to drive both electrolysers with no additional energy input. The solar concentration is adjusted such that the maximum power point of the photovoltaic is well matched to the operating capacity of the electrolysers to optimize the system efficiency. The system achieves a 48-h average STH efficiency of 30%. These results demonstrate the potential of photovoltaic-electrolysis systems for cost-effective solar energy storage.

  15. Solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen efficiency over 30%

    Science.gov (United States)

    Jia, Jieyang; Seitz, Linsey C.; Benck, Jesse D.; Huo, Yijie; Chen, Yusi; Ng, Jia Wei Desmond; Bilir, Taner; Harris, James S.; Jaramillo, Thomas F.

    2016-10-01

    Hydrogen production via electrochemical water splitting is a promising approach for storing solar energy. For this technology to be economically competitive, it is critical to develop water splitting systems with high solar-to-hydrogen (STH) efficiencies. Here we report a photovoltaic-electrolysis system with the highest STH efficiency for any water splitting technology to date, to the best of our knowledge. Our system consists of two polymer electrolyte membrane electrolysers in series with one InGaP/GaAs/GaInNAsSb triple-junction solar cell, which produces a large-enough voltage to drive both electrolysers with no additional energy input. The solar concentration is adjusted such that the maximum power point of the photovoltaic is well matched to the operating capacity of the electrolysers to optimize the system efficiency. The system achieves a 48-h average STH efficiency of 30%. These results demonstrate the potential of photovoltaic-electrolysis systems for cost-effective solar energy storage.

  16. A Novel Type of Thermal Solar Water Disinfection Unit

    OpenAIRE

    Dietl, Jochen; Engelbart, Hendryk; Sielaff, Axel

    2015-01-01

    A novel type of solar thermal water disinfection unit is presented in this work. The system is safe and easy to use and can be built with basic tools and widely available materials. In the unit, water is disinfected by temperature increase up to the boiling point and output is controlled by the change in density. For employing the change in density to control the water output, a dimensioning procedure is suggested, giving the required height of the water reservoir, the heating section and ...

  17. Principles, efficiency, and blueprint character of solar-energy conversion in photosynthetic water oxidation.

    Science.gov (United States)

    Dau, Holger; Zaharieva, Ivelina

    2009-12-21

    , photoinhibitory, protective, and repair processes. The overpotential for catalysis of water oxidation at the Mn(4)Ca complex of PSII may be as low as 0.3 V. To address the specific energetics of water oxidation at the Mn complex of PSII, we propose a new conceptual framework that will facilitate quantitative considerations on the basis of oxidation potentials and pK values. In conclusion, photosynthetic water oxidation works at high efficiency and thus can serve as both an inspiring model and a benchmark in the development of future technologies for production of solar fuels.

  18. Can solar water-treatment really help in the fight against water shortages?

    Science.gov (United States)

    Fernàndez-Ibañez, Pilar; McGuigan, Kevin G.; Fatta-Kassinos, Despo

    2017-06-01

    In the face of increasing global population, rising industrialization and the inescapable reality of climate change, the demand for access to clean, safe water has never been greater. Solar wastewater remediation technologies and solar water-treatment have the potential to contribute significantly towards affordable and sustainable solutions to this seemingly intractable problem. They do this by using solar energy to treat water from sources that previously would have been considered unsuitable for further use. In this article we reveal the basic principles surrounding the design and application of solar remediation reactors for urban wastewater treatment and reuse and then show how even simpler technologies are being used in low-income communities to provide affordable and safe potable water.

  19. Livestock water pumping with wind and solar power

    Science.gov (United States)

    Recent developments in pumping technologies have allowed for efficient use of renewable energies like wind and solar to power new pumps for remote water pumping. A helical type, positive displacement pump was developed a few years ago and recently modified to accept input from a variable power sourc...

  20. development of an automated batch-process solar water disinfection ...

    African Journals Online (AJOL)

    user

    1,3 NATIONAL CENTRE FOR ENERGY RESEARCH AND DEVELOPMENT, UNIV. ... The system disinfected 11 litres of water in a day for solar ... all life forms. .... This cycle goes on and on. 2.5 Immobilization of TiO2 Unto the Glass Rod.

  1. Solar space and water heating system installed at Charlottesville, Virginia

    Energy Technology Data Exchange (ETDEWEB)

    Greer, Charles R.

    1980-09-01

    The solar energy system located at David C. Wilson Neuropsychiatric Hospital, Charlottesville, Virginia, consists of 88 single glazed, Sunworks Solector copper base plate collector modules; hot water coils in the hot air ducts; a domestic hot water (DHW) preheat tank; a 3,000 gallon concrete urethane-insulated storage tank and other miscellaneous components. This report includes extracts from the site files, specifications, drawings, installation, operation and maintenance instructions.

  2. Innovative Sustainable Water Management Practices in Solar Residential Design

    OpenAIRE

    C. Jason Mabry; Franca Trubiano

    2012-01-01

    This paper communicates the results of an architectural research project which sought innovative design strategies for achieving energy and resource efficiencies in water management systems traditionally used in single-family housing. It describes the engineering of an efficient, multifaceted, and fully integrated water management system for a domesticenvironment of 800 sq. ft., entirely powered by solar energy. The four innovations whose details are conveyed include the use of alternate mate...

  3. Deterministically Driven Avalanche Models of Solar Flares

    Science.gov (United States)

    Strugarek, Antoine; Charbonneau, Paul; Joseph, Richard; Pirot, Dorian

    2014-08-01

    We develop and discuss the properties of a new class of lattice-based avalanche models of solar flares. These models are readily amenable to a relatively unambiguous physical interpretation in terms of slow twisting of a coronal loop. They share similarities with other avalanche models, such as the classical stick-slip self-organized critical model of earthquakes, in that they are driven globally by a fully deterministic energy-loading process. The model design leads to a systematic deficit of small-scale avalanches. In some portions of model space, mid-size and large avalanching behavior is scale-free, being characterized by event size distributions that have the form of power-laws with index values, which, in some parameter regimes, compare favorably to those inferred from solar EUV and X-ray flare data. For models using conservative or near-conservative redistribution rules, a population of large, quasiperiodic avalanches can also appear. Although without direct counterparts in the observational global statistics of flare energy release, this latter behavior may be relevant to recurrent flaring in individual coronal loops. This class of models could provide a basis for the prediction of large solar flares.

  4. Solar hot water systems application to the solar building test facility and the Tech House

    Science.gov (United States)

    Goble, R. L.; Jensen, R. N.; Basford, R. C.

    1976-01-01

    Projects which relate to the current national thrust toward demonstrating applied solar energy are discussed. The first project has as its primary objective the application of a system comprised of a flat plate collector field, an absorption air conditioning system, and a hot water heating system to satisfy most of the annual cooling and heating requirements of a large commercial office building. The other project addresses the application of solar collector technology to the heating and hot water requirements of a domestic residence. In this case, however, the solar system represents only one of several important technology items, the primary objective for the project being the application of space technology to the American home.

  5. Solar-energy mobile water aerators are efficient for restoring eutrophic water

    Science.gov (United States)

    Wang, Y. Y.; Xu, Z. X.

    2017-01-01

    Surface water eutrophication has become a worldwide social issue. large amounts of secondhand energy, high capital investment are required, and most ecosystem disturbances will arise in the conventional eutrophication restoration measures. However, mobile solar-energy water aerator has the better oxygen transfer rate, hydrodynamic condition and can be used in the large waterbody for its cruising character. Second, the device is low carbon and sustainable for the solar photovoltaic system applications. So the device can be widely used in the eutrophication restoration.

  6. Modeling light trapping in nanostructured solar cells.

    Science.gov (United States)

    Ferry, Vivian E; Polman, Albert; Atwater, Harry A

    2011-12-27

    The integration of nanophotonic and plasmonic structures with solar cells offers the ability to control and confine light in nanoscale dimensions. These nanostructures can be used to couple incident sunlight into both localized and guided modes, enhancing absorption while reducing the quantity of material. Here we use electromagnetic modeling to study the resonances in a solar cell containing both plasmonic metal back contacts and nanostructured semiconductor top contacts, identify the local and guided modes contributing to enhanced absorption, and optimize the design. We then study the role of the different interfaces and show that Al is a viable plasmonic back contact material.

  7. Helioseismology challenges models of solar convection

    CERN Document Server

    Gizon, Laurent; 10.1073/pnas.1208875109

    2012-01-01

    Convection is the mechanism by which energy is transported through the outermost 30% of the Sun. Solar turbulent convection is notoriously difficult to model across the entire convection zone where the density spans many orders of magnitude. In this issue of PNAS, Hanasoge et al. (2012) employ recent helioseismic observations to derive stringent empirical constraints on the amplitude of large-scale convective velocities in the solar interior. They report an upper limit that is far smaller than predicted by a popular hydrodynamic numerical simulation.

  8. Operation Performance of Central Solar Heating System with Seasonal Storage Water Tank in Harbin

    Institute of Scientific and Technical Information of China (English)

    YE Ling; JIANG Yi-qiang; YAO Yang; ZHANG Shi-cong

    2009-01-01

    This paper presented a preliminary research on the central solar heating system with seasonal stor-age(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in the central solar heating system was firstly developed based on energy conservation.This was fol-lowed by the simulation of the CSHSSS used in a two-floor villa in Harbin,and analysis of the impacts on storage water temperature of tank volume,solar collector area,tank burial depth,insulation thickness around the tank,etc.The results show there is a relatively economical tank volume to optimize the system efficiency,which de-creases with increasing tank volume at the constant collector area,and increases with increasing collector area at the constant tank volume.Furthermore,the insulation thickness has obvious effect on avoiding heat loss,while the tank burial depth doesn't.In addition-the relationship between the solar collector efficiency and storage wa-ter temperature is also obtained,it decreases quickly with increasing storing water temperature,and then in-creases slowly after starting space heating system.These may be helpful for relevant design and optimization in cold climates in China and all over the world.

  9. Solar Energy in China: Development Trends for Solar Water Heaters and Photovoltaics in the Urban Environment

    Science.gov (United States)

    Wallace, William; Wang, Zhongying

    2006-01-01

    China is the world's largest market for solar water heating systems, installing 13 million square meters of new systems in 2004, mostly in large cities. Municipal authorities, however, are sensitive to quality and visual impact issues created by this technology deployment. Therefore, there is currently a trend toward developing building integrated…

  10. Solar Energy in China: Development Trends for Solar Water Heaters and Photovoltaics in the Urban Environment

    Science.gov (United States)

    Wallace, William; Wang, Zhongying

    2006-01-01

    China is the world's largest market for solar water heating systems, installing 13 million square meters of new systems in 2004, mostly in large cities. Municipal authorities, however, are sensitive to quality and visual impact issues created by this technology deployment. Therefore, there is currently a trend toward developing building integrated…

  11. new model for solar radiation estimation from measured air ...

    African Journals Online (AJOL)

    HOD

    Nigerian Meteorological Agency (NIMET) were used as inputs to the ANFIS model and monthly mean global solar radiation was ... models were used to predict solar radiation in Nigeria by. [12-15]. .... calculate them as total output [32] and [34].

  12. An overview of water disinfection in developing countries and the potential for solar thermal water pasteurization

    Energy Technology Data Exchange (ETDEWEB)

    Burch, J.; Thomas, K.E.

    1998-01-01

    This study originated within the Solar Buildings Program at the U.S. Department of Energy. Its goal is to assess the potential for solar thermal water disinfection in developing countries. In order to assess solar thermal potential, the alternatives must be clearly understood and compared. The objectives of the study are to: (a) characterize the developing world disinfection needs and market; (b) identify competing technologies, both traditional and emerging; (c) analyze and characterize solar thermal pasteurization; (d) compare technologies on cost-effectiveness and appropriateness; and (e) identify research opportunities. Natural consequences of the study beyond these objectives include a broad knowledge of water disinfection problems and technologies, introduction of solar thermal pasteurization technologies to a broad audience, and general identification of disinfection opportunities for renewable technologies.

  13. ANALYSIS AND MODELING OF SOLAR EVAPORATOR-COLLECTOR

    Directory of Open Access Journals (Sweden)

    Zakaria Mohd. Amin

    2015-11-01

    Full Text Available Solar energy is considered a sustainable resource that poses little to no harmful effects on the environment. The performance of a solar system depends to a great extent on the collector used for the conversion of solar radiant energy to thermal energy. A solar evaporator-collector (SEC is basically an unglazed flat plate collector where refrigerants, such as R134a is used as the working fluid. As the operating temperature of the SEC is very low, it utilizes both solar irradiation and ambient energy leading to a much higher efficiency than the conventional collectors. This capability of SECs to utilize ambient energy also enables the system to operate at night. This type of collector can be locally made and is relatively much cheaper than the conventional collector.   At the National University of Singapore, the evaporator-collector was integrated to a heat pump and the performance was investigated for several thermal applications: (i water heating, (ii drying and (iii desalination. A 2-dimensional transient mathematical model of this system was developed and validated by experimental data. The present study provides a comprehensive study of performance. KEYWORDS: heat pump; evaporator-collector.

  14. Solar Advisor Model User Guide for Version 2.0

    Energy Technology Data Exchange (ETDEWEB)

    Gilman, P.; Blair, N.; Mehos, M.; Christensen, C.; Janzou, S.; Cameron, C.

    2008-08-01

    The Solar Advisor Model (SAM) provides a consistent framework for analyzing and comparing power system costs and performance across the range of solar technologies and markets, from photovoltaic systems for residential and commercial markets to concentrating solar power and large photovoltaic systems for utility markets. This manual describes Version 2.0 of the software, which can model photovoltaic and concentrating solar power technologies for electric applications for several markets. The current version of the Solar Advisor Model does not model solar heating and lighting technologies.

  15. Decentralized water purification using solar thermal energy

    NARCIS (Netherlands)

    Bhardwaj, R.

    2016-01-01

    Provision of clean drinking water to poor can prevent a large number of deaths and illnesses amongst children around the world. In 2010, about 0.75 million child deaths were caused due to diarrhea, and a further 22.5 million years of life were lost due to ill-health, disability or early

  16. Decentralized water purification using solar thermal energy

    NARCIS (Netherlands)

    Bhardwaj, R.

    2016-01-01

    Provision of clean drinking water to poor can prevent a large number of deaths and illnesses amongst children around the world. In 2010, about 0.75 million child deaths were caused due to diarrhea, and a further 22.5 million years of life were lost due to ill-health, disability or early

  17. Cold water inlet in solar tanks - valuation

    DEFF Research Database (Denmark)

    Andersen, Elsa

    1999-01-01

    The aim of the project is to make a proposal for how to value a storage tank with a poor design of the cold water inlet. Based on measurements and calculations a number of curves, which are valid for this valuation, are worked out. Based on a simple test with a uniform heated storage tank the ratio...

  18. Development of three-dimensional magnetohydrodynamic model for solar corona and solar wind simulation

    Science.gov (United States)

    Yuan, Xingqiu; Trichtchenko, Larisa; Boteler, David

    Propagation of coronal mass ejections from solar surface to the Earth magnetosphere is strongly influenced by the conditions in solar corona and ambient solar wind. Thus, reliable simulation of the background solar wind is the primary task toward the development of numerical model for the transient events. In this paper we introduce a new numerical model which has been specifically designed for numerical study of the solar corona and ambient solar wind. This model is based on our recently developed three-dimensional Spherical Coordinate Adaptive Magneto-Hydro-Dynamic (MHD) code (SCA-MHD-3D) [Yuan et al., 2009]. Modifications has been done to include the observed magnetic field at the photosphere as inner boundary conditions. The energy source term together with reduced plasma gamma are used in the nonlinear MHD equations in order to simulate the solar wind acceleration from subsonic speed at solar surface to supersonic speed at the inter-heliosphere region, and the absorbing boundary conditions are used at the solar surface. This model has been applied to simulate the background solar wind condition for several different solar rotations, and comparison between the observation and model output have shown that it reproduces many features of solar wind, including open and closed magnetic fields, fast and slow solar wind speed, sector boundaries, etc.

  19. Water heating solar system for popular houses; Sistema solar de aquecimento de agua para residencias populares

    Energy Technology Data Exchange (ETDEWEB)

    Mogawer, Tamer; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis], e-mail: teofilo@feg.unesp.br

    2004-07-01

    In this paper we present a case study for the design of a low cost solar heating system for a popular residence in an isolated rural community in the state of Rio Grande do Norte. This scaling can be extended to several rural communities that are in the same situation in Brazil as well as the wider use of solar power between the low-income people who do not have the benefits of electricity in their homes or want to have a lower cost of electricity. In this context, there are very interesting alternatives, among which is the replacement of electric heating bath water by heating by solar energy. According to several sources the electric shower, as it is now simple and extremely cheap, is the villain of the national electrical system. It is used in peak hours of consumption, something like 10% of electric generating capacity installed in Brazil, forcing many industries to switch off the machines because of the high cost of electricity during this period. Using the heating by solar energy, we can reduce consumption of electric shower and also increase the use of clean energy in popular homes and in isolated rural communities. This paper will address the use of solar energy with the basic purpose of heating water for bathing in popular residences and in isolated rural areas, using low cost systems, built with easily materials that is found in any area of the country. (author)

  20. Photocatalytic water treatment: practical applications with solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Malato, S.; Maldonado, M.I.; Blanco, J.; Caceres, J.; Gernjak, W.; Alarcon, D.C. [Plataforma Solar de Almeria-CIEMAT, Tabernas, Almeria (Spain)

    2003-07-01

    The experimental systems necessary to carry out pilot-plant-scale solar photocatalytic experiments are described and the basic components of these plants and fundamental parameters related to solar photocatalytic reactions are outlined. An attempt has been made to summarize the results obtained with different contaminants and real wastewater at different initial concentrations. The general procedure for obtaining ''design parameters'' is also commented on. Moreover, other aspects closely related to the enhancement of photocatalytic applications in water, such as the use of toxicity bioassays, have also been outlined. (orig.)

  1. All inorganic semiconductor nanowire mesh for direct solar water splitting.

    Science.gov (United States)

    Liu, Bin; Wu, Cheng-Hao; Miao, Jianwei; Yang, Peidong

    2014-11-25

    The generation of chemical fuels via direct solar-to-fuel conversion from a fully integrated artificial photosynthetic system is an attractive approach for clean and sustainable energy, but so far there has yet to be a system that would have the acceptable efficiency, durability and can be manufactured at a reasonable cost. Here, we show that a semiconductor mesh made from all inorganic nanowires can achieve unassisted solar-driven, overall water-splitting without using any electron mediators. Free-standing nanowire mesh networks could be made in large scales using solution synthesis and vacuum filtration, making this approach attractive for low cost implementation.

  2. Solar water heating for aquaculture : optimizing design for sustainability

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, M.; Thwaites, J. [Taylor Munro Energy Systems Inc., Delta, BC (Canada)

    2003-08-01

    This paper presents the results of a solar water heating project at Redfish Ranch, the first Tilapia tropical fish farm in British Columbia. The fish are raised in land-based tanks, eliminating the risk of contamination of local ecosystems. As a tropical species, they requires warm water. Natural gas or propane boilers are typically used to maintain tank temperatures at 26 to 28 degrees C. Redfish Ranch uses solar energy to add heat to the fish tanks, thereby reducing fossil-fuel combustion and greenhouse gas emissions. This unique building-integrated solar system is improving the environmental status of of this progressive industrial operation by offsetting fossil-fuel consumption. The system was relatively low cost, although substantial changes had to be made to the roof of the main building. The building-integrated design of the solar water heating system has reduced operating costs, generated local employment, and shows promise of future activity. As such, it satisfies the main criteria for sustainability. 7 refs.

  3. Solar energy conversion by photocatalytic overall water splitting

    KAUST Repository

    Takanabe, Kazuhiro

    2015-07-04

    Summary: Solar energy is abundant and renewable energy: however, extensive conversion of the solar energy can only be achieved by large-scale collection of solar flux. The technology that satisfies this requirement must be as simple as possible to reduce capital cost. Overall water splitting (OWS) by powder-form photocatalysts directly produces H2 as a chemical energy in a single reactor, which does not require any complicated parabolic mirrors and electronic devices. Because of its simplicity and low capital cost, it has tremendous potential to become the major technology of solar energy conversion. To achieve the OWS efficiently, the development of efficient photocatalysts is mandatory. The OWS hotocatalysis involves the electrocatalys is for both water reduction and oxidation on the surafce of photocatalysts, which is driven by particular semiconductors that absorb photons to generate excited carriers. Such photocatalysts must be designed to maximize the charge separation efficiency at the catalyst-semiconductor and semiconductor-electrolyte interface. In addition the low-overpotential electrocatalyts towards water redox reactions should be insensitive to the back-reaction of the produced H2 and O2 that produces H2O. In this presentation, some recent progress on the topic of the OWS in our group will be discussed.

  4. Remote sensing of water vapor within the solar spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, B. [Univ. Hamburg (Germany). Meteorologisches Inst.; Bakan, S. [Max-Planck-Inst. fuer Meteorologie, Hamburg (Germany); Fischer, J. [Freie Univ. Berlin (Germany). Inst. fuer Weltraumwissenschaften

    1995-12-31

    Water vapor is the most important natural atmospheric greenhouse gas, influencing strongly solar and thermal infrared radiative transfer, and giving rise for clouds, which have strong influence on weather and climate. Therefore, much effort is devoted to remote sensing of atmospheric water vapor. The detection over water is well established, while the situation over land surfaces is worse. A new method is developed to derive the total atmospheric water vapor content over land surfaces even for higher aerosol contents with the aid of backscattered solar radiances. Numerous radiative transfer simulations with a matrix operator code of vertically backscattered solar radiance were carried out for different vertically stratified atmospheres. From the evaluation of these theoretical calculations it can be concluded that this technique allows the detection of total atmospheric water vapor content over land surfaces with an error of less than 10%. This result is important with regard to future measurements planned with the MERIS imaging spectrometer on board the European satellite ENVISAT, which will be launched in 1998. In addition to these theoretical calculations also various aircraft measurements of the backscattered radiances in the wavelength range from 600 to 1,650 nm were carried out. These measurements are done with the above mentioned OVID, a new multichannel array spectrometer of the Universities of Hamburg and Berlin. First comparisons of these airborne CCD measurements with calculated spectra are shown.

  5. Solar photocatalysis. A clean process for water detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Robert, Didier [LCA: Environnement et procedes propres, Universite de Metz, Rue Victor Demange, 57500 Saint Avold (France); Malato, Sixto [CIEMAT, Plataforma Solar de Almeria, P.O. Box 22, 04200 Tabernas (Spain)

    2002-05-27

    The photocatalytic degradation of various toxic organic compounds has been proposed as a viable process to detoxify drinking water. Irradiating pulverulent semi-conductors like TiO{sub 2} in suspension or fixed to various supports in aqueous solutions containing organic pollutants, creates a redox environment able to destroy these pollutants. Solar photocatalytic mineralization of organic water pollutants has a strong potential in the industrial destruction of toxic organics in water as this has been widely demonstrated in recent years, and the applications and target compounds are numerous. The aim of this paper is to present the basic principle of the photocatalysis and especially to show the various applications of the solar photocatalysis in the field of the decontamination of wastewater.

  6. Water heating solar system using collector with polycarbonate absorber surface

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luiz Guilherme Meira de; Sodre, Dilton; Cavalcanti, Eduardo Jose Cidade; Souza, Luiz Guilherme Vieira Meira de; Mendes, Jose Ubiragi de Lima [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)], e-mails: lguilherme@dem.ufrn.br, diltonsodre@ifba.edu.br, ubiragi@ct.ufrn.br

    2010-07-01

    It is presented s solar collector to be used in a heating water for bath system, whose main characteristics are low cost and easy fabrication and assembly processes. The collector absorber surface consists of a polycarbonate plate with an area of 1.5 m{sup 2}. The water inlet and outlet are made of PVC 50mm, and were coupled to a 6mm thick polycarbonate plate using fiberglass resin. A 200 liters thermal reservoir will be used. This reservoir is also alternative. The absorber heating system works under thermo-siphon regimen. Thermal parameters will be evaluated to prove the feasibility of the studied solar heating system to obtain bath water for a four people family. (author)

  7. Solar photocatalysis: a clean process for water detoxification.

    Science.gov (United States)

    Robert, Didier; Malato, Sixto

    2002-05-27

    The photocatalytic degradation of various toxic organic compounds has been proposed as a viable process to detoxify drinking water. Irradiating pulverulent semi-conductors like TiO2 in suspension or fixed to various supports in aqueous solutions containing organic pollutants, creates a redox environment able to destroy these pollutants. Solar photocatalytic mineralization of organic water pollutants has a strong potential in the industrial destruction of toxic organics in water as this has been widely demonstrated in recent years, and the applications and target compounds are numerous. The aim of this paper is to present the basic principle of the photocatalysis and especially to show the various applications of the solar photocatalysis in the field of the decontamination of wastewater.

  8. Drinking water treatment in solar reactors with immobilized photocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Sichel, C.; Fernandez, P.; Blanco, J.; Lorenz, K.

    2005-07-01

    This work has been performed at the Plataforma Solar de Almeria. As in our daily consumption of any other good, it is important to take an interest in sustainable treatment methods for purifying a vital water supply. Primary water treatment has no need for energy consuming techniques as any suspended particles can usually be removed by sand traps and sedimentation basin. Organic matter and biodegradable chemical contaminants ca be decomposed by activated sludge plants, bacteria beds, or in the case of highly organically loaded sewage by methanisation.In the recent years, another photocatalysts a photo sensitizer has been used in desinfection experiments. Ruthenium appears to have good potential for inactivation of bacteria in chelating coordination compounds. The SOLWATER project attempts to provide remote areas of such developing countries as Mexico, Peru and Argentina with drinking water disinfected by solar photocatalysis with immobilized TiO2 and Ru(II). (Author)

  9. Enabling unassisted solar water splitting by iron oxide and silicon

    Science.gov (United States)

    Jang, Ji-Wook; Du, Chun; Ye, Yifan; Lin, Yongjing; Yao, Xiahui; Thorne, James; Liu, Erik; McMahon, Gregory; Zhu, Junfa; Javey, Ali; Guo, Jinghua; Wang, Dunwei

    2015-06-01

    Photoelectrochemical (PEC) water splitting promises a solution to the problem of large-scale solar energy storage. However, its development has been impeded by the poor performance of photoanodes, particularly in their capability for photovoltage generation. Many examples employing photovoltaic modules to correct the deficiency for unassisted solar water splitting have been reported to-date. Here we show that, by using the prototypical photoanode material of haematite as a study tool, structural disorders on or near the surfaces are important causes of the low photovoltages. We develop a facile re-growth strategy to reduce surface disorders and as a consequence, a turn-on voltage of 0.45 V (versus reversible hydrogen electrode) is achieved. This result permits us to construct a photoelectrochemical device with a haematite photoanode and Si photocathode to split water at an overall efficiency of 0.91%, with NiFeOx and TiO2/Pt overlayers, respectively.

  10. Doping-Promoted Solar Water Oxidation on Hematite Photoanodes

    Directory of Open Access Journals (Sweden)

    Yuchao Zhang

    2016-07-01

    Full Text Available As one of the most promising materials for solar water oxidation, hematite has attracted intense research interest for four decades. Despite their desirable optical band gap, stability and other attractive features, there are great challenges for the implementation of hematite-based photoelectrochemical cells. In particular, the extremely low electron mobility leads to severe energy loss by electron hole recombination. Elemental doping, i.e., replacing lattice iron with foreign atoms, has been shown to be a practical solution. Here we review the significant progresses in metal and non-metal element doping-promoted hematite solar water oxidation, focusing on the role of dopants in adjusting carrier density, charge collection efficiency and surface water oxidation kinetics. The advantages and salient features of the different doping categories are compared and discussed.

  11. Mathematical model development for a new solar desalination system (SDS)

    Energy Technology Data Exchange (ETDEWEB)

    Elsafty, A.F.; Amer, A.M. [Mechanical and Marine Engineering Department, College of Engineering and Technology, Arab Academy for Science, Technology and Maritime Transport, P.O. Box 1029, Alexandria (Egypt); Fath, H.E. [Mechanical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria (Egypt)

    2008-11-15

    Supply of adequate quantities of fresh potable water is one of the most serious problems confronting human especially when we know that one third of the world population are suffering from water shortage and it is expected to reach two thirds in the near future. Therefore, desalination, as a non-conventional water resource, has become one of the most interesting alternative water sources to partially face the fresh water shortage in the near future. The objective of this study is to obtain a general mathematical model for a newly developed solar still that uses parabolic reflector-tube absorber desalination technology. A computer program has been developed to simulate the still operation and to solve the governing heat and mass transfer action, which occurs during the operation. The program will then be used to study the still production in different cases. The study revealed that increasing the solar intensity, ambient temperature, efficiency of reflector material, reflector aperture area, and evaporation area increases the unit productivity. On the other hand, increasing wind velocity, saline water depth, condenser emissivity, and condenser thickness have a small effect on the productivity. (author)

  12. An update of Leighton's solar dynamo model

    CERN Document Server

    Cameron, R H

    2016-01-01

    In 1969 Leighton developed a quasi-1D mathematical model of the solar dynamo, building upon the phenomenological scenario of Babcock(1961). Here we present a modification and extension of Leighton's model. Using the axisymmetric component of the magnetic field, we consider the radial field component at the solar surface and the radially integrated toroidal magnetic flux in the convection zone, both as functions of latitude. No assumptions are made with regard to the radial location of the toroidal flux. The model includes the effects of turbulent diffusion at the surface and in the convection zone, poleward meridional flow at the surface and an equatorward return flow affecting the toroidal flux, latitudinal differential rotation and the near-surface layer of radial rotational shear, downward convective pumping of magnetic flux in the shear layer, and flux emergence in the form of tilted bipolar magnetic regions. While the parameters relevant for the transport of the surface field are taken from observations,...

  13. Application of solar energy to the supply of hot water for textile dyeing. Final report, CDRL/PA 10

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-09-01

    The design plan for a solar process hot water system for a textile dye beck at Riegel Textile Corporation's LaFrance, South Carolina, facilities is presented. The solar system consists of 396 GE model TC 100 evacuated tube collector modules arranged in a ground mounted array with a total collector area of 6680 square feet. The system includes an 8000-gallon hot water storage tank. Systems analyses, specification sheets, performance data, and an economic evaluation of the proposed system are presented. (WHK)

  14. Solar hydrogen production on some water splitting photocatalysts

    Science.gov (United States)

    Takata, Tsuyoshi; Hisatomi, Takashi; Domen, Kazunari

    2016-09-01

    Photocatalytic overall water splitting into H2 and O2 is expected to be a promising method for the efficient utilization of solar energy. The design of optimal photocatalyst structures is a key to efficient overall water splitting, and the development of photocatalysts which can efficiently convert large portion of visible light spectrum has been required. Recently, a series of complex perovskite type transition metal oxynitrides, LaMgxT 1-xO1+3xN2-3x, was developed as photocatalysts for direct water splitting operable at wide wavelength of visible light. In addition two-step excitation water splitting via a novel photocatalytic device termed as photocatalyst sheet was developed. This consists of two types of semiconductors (hydrogen evolution photocatalyst and oxygen evolution photocatalyst) particles embedded in a conductive layer, and showed high efficiency for overall water splitting. These recent advances in photocatalytic water splitting were introduced.

  15. Estimation of Hourly Solar Radiation at the Surface under Cloudless Conditions on the Tibetan Plateau Using a Simple Radiation Model

    Institute of Scientific and Technical Information of China (English)

    LIANG Hong; ZHANG Renhe; LIU Jingmiao; SUN Zhian; CHENG Xinghong

    2012-01-01

    In this study,the clear sky hourly global and net solar irradiances at the surface determined using SUNFLUX,a simple parameterization scheme,for three stations (Gaize,Naqu,and Lhasa) on the Tibetan Plateau were evaluated against observation data.Our modeled results agree well with observations.The correlation coefficients between modeled and observed values were >0.99 for all three stations.The relative error of modeled results,in average was < 7%,and the root-mean-square variance was < 27 W m-2.The solar irradiances in the radiation model were slightly overestimated compared with observation data;there were at least two likely causes.First,the radiative effects of aerosols were not included in the radiation model.Second,solar irradiances determined by thermopile pyranometers include a thermal offset error that causes solar radiation to be slightly underestimated.The solar radiation absorbed by the ozone and water vapor was estimated. The results show that monthly mean solar radiation absorbed by the ozone is < 2% of the global solar radiation (< 14 W m-2).Solar radiation absorbed by water vapor is stronger in summer than in winter.The maximum amount of monthly mean solar radiation absorbed by water vapor can be up to 13% of the global solar radiation (95W m-2).This indicates that water vapor measurements with high precision are very important for precise determination of solar radiation.

  16. Computer-Aided Design, Modeling and Simulation of a New Solar Still Design

    Directory of Open Access Journals (Sweden)

    Jeremy (Zheng Li

    2011-01-01

    Full Text Available The clean and pure drinking water is important in today's life but current water sources are usually brackish with bacteria that cannot be used for drinking. About 78% of water available in the sea is salty, 21% of water is brackish, and only 1% of water is fresh. Distillation is one of the feasible processes applied to water purification, and it requires the energy inputs, such as solar radiation. Water is evaporated in this distillation process and water vapor can be separated and condensed to pure water. Now, with the change from conventional fuels to renewable and environment friendly fuels sources, the modern technology allows to use the abundant energy from the sun. It is better to use solar energy to process the water desalination since it is more economical than the use of conventional energies. The main focus of this paper is applying computer-aided modeling and simulation to design a less complex solar water distillation system. The prototype of this solar still system is also built to verify its feasibility, functionality, and reliability. The computational simulation and prototype testing show the reliability and proper functionality of this solar water distillation system.

  17. Early accretion of water and volatile elements to the inner Solar System: evidence from angrites

    Science.gov (United States)

    Sarafian, Adam R.; Hauri, Erik H.; McCubbin, Francis M.; Lapen, Thomas J.; Berger, Eve L.; Nielsen, Sune G.; Marschall, Horst R.; Gaetani, Glenn A.; Righter, Kevin; Sarafian, Emily

    2017-04-01

    Inner Solar System bodies are depleted in volatile elements relative to chondrite meteorites, yet the source(s) and mechanism(s) of volatile-element depletion and/or enrichment are poorly constrained. The timing, mechanisms and quantities of volatile elements present in the early inner Solar System have vast implications for diverse processes, from planetary differentiation to the emergence of life. We report major, trace and volatile-element contents of a glass bead derived from the D'Orbigny angrite, the hydrogen isotopic composition of this glass bead and that of coexisting olivine and silicophosphates, and the 207Pb-206Pb age of the silicophosphates, 4568 ± 20 Ma. We use volatile saturation models to demonstrate that the angrite parent body must have been a major body in the early inner Solar System. We further show via mixing calculations that all inner Solar System bodies accreted volatile elements with carbonaceous chondrite H and N isotope signatures extremely early in Solar System history. Only a small portion (if any) of comets and gaseous nebular H species contributed to the volatile content of the inner Solar System bodies. This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'.

  18. Early accretion of water and volatile elements to the inner Solar System: evidence from angrites.

    Science.gov (United States)

    Sarafian, Adam R; Hauri, Erik H; McCubbin, Francis M; Lapen, Thomas J; Berger, Eve L; Nielsen, Sune G; Marschall, Horst R; Gaetani, Glenn A; Righter, Kevin; Sarafian, Emily

    2017-05-28

    Inner Solar System bodies are depleted in volatile elements relative to chondrite meteorites, yet the source(s) and mechanism(s) of volatile-element depletion and/or enrichment are poorly constrained. The timing, mechanisms and quantities of volatile elements present in the early inner Solar System have vast implications for diverse processes, from planetary differentiation to the emergence of life. We report major, trace and volatile-element contents of a glass bead derived from the D'Orbigny angrite, the hydrogen isotopic composition of this glass bead and that of coexisting olivine and silicophosphates, and the (207)Pb-(206)Pb age of the silicophosphates, 4568 ± 20 Ma. We use volatile saturation models to demonstrate that the angrite parent body must have been a major body in the early inner Solar System. We further show via mixing calculations that all inner Solar System bodies accreted volatile elements with carbonaceous chondrite H and N isotope signatures extremely early in Solar System history. Only a small portion (if any) of comets and gaseous nebular H species contributed to the volatile content of the inner Solar System bodies.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

  19. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-01-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  20. Recent developments in solar H2 generation from water splitting

    Indian Academy of Sciences (India)

    Sivaraman Rajaambal; Kumarsrinivasan Sivaranjani; Chinnakonda S Gopinath

    2015-01-01

    Hydrogen production from water and sunlight through photocatalysis could become one of the channels, in the not-so-distant future, to meet a part of ever growing energy demands. However, accomplishing solar water splitting through semiconductor particulate photocatalysis seems to be the ‘Holy Grail’ problem of science. In the present mini-review, some of the critical strategies of semiconductor photocatalysis are focused with the aim of enumerating underlying critical factors such as visible light harvesting, charge carrier separation, conduction and their utilization that determine the quantum efficiency. We attempted to bring out the essential requirements expected in a material for facile water splitting by explaining important and new designs contributed in the last decade. The newly emerged designs in semiconductor architecture employing nanoscience towards meeting the critical factors of facile photocatalysis are elucidated. The importance of band gap engineering is emphasized to utilize potential wide band gap semiconductors. Assistance of metal nanostructures and quantum dots to semiconductors attains vital importance as they are exuberant visible light harvesters and charge carrier amplifiers. Benevolent use of quantum dots in solar water splitting and photoelectrochemical water splitting provides scope to revolutionize the quantum efficiency by its multiple exciton generation features. A list of drawbacks and issues that hamper the much needed breakthrough in photocatalysis of water splitting is provided to invite attention to address them and move towards sustainable water splitting.

  1. Cold water inlet in solar tanks - valuation

    DEFF Research Database (Denmark)

    Andersen, Elsa

    1999-01-01

    The aim of the project is to make a proposal for how to value a storage tank with a poor design of the cold water inlet. Based on measurements and calculations a number of curves, which are valid for this valuation, are worked out. Based on a simple test with a uniform heated storage tank the ratio...... between the energy tapped in one storage volume and the energy content in the tank before the tapping is measured. Afterwards the mixing factor, corresponding to the measured ratio, can be determined. It is proposed that the mixing factor is taken into consideration when the governmental subsidy for SDHW...

  2. Large Bandgap Semiconductors for Solar Water Splitting

    DEFF Research Database (Denmark)

    Malizia, Mauro

    water splitting devices having tandem design. The increase of the photovoltage produced by GaP under illumination was the main goal of this work. GaP has a bandgap of 2.25 eV and could in theory produce a photovoltage of approximately 1.7 V. Instead, the photovoltage produced by the semiconductor...... density generated by GaP was increased by more than 60% by electrochemical etching of the surface. The etching process produces a rough microstructured surface that increases the optical path length of the incident photons and the collection of photogenerated electrons.Furthermore, the synthesis of BiVO4...

  3. solar magnetic fiber and space solar telescope in engineering model

    Science.gov (United States)

    Ai, G.

    The solar magnetic fiber and the magnetic element are the most important factor in the solar activity and solar atmosphere. Because the space resolution of measurement of solar magnetic field is much lower than that of the size of the nature solar magnetic fiber and element from the earth atmospheric turbulence. The estimate of the magnetic element nature from various indirect researches shows great difference with several orders. The research results about magnetic elements have been reviewed in the paper.Because the size of the magnetic element has been estimated for 0.1T-0.2T, the space solar magnetic field telescope with big diameter is the most basic choice. For the exploration of solar magnetic fiber and element, a Space Solar Telescope is under development in the phase C and D, there are five payloads which are: 1) MOT, 1 diameter telescope with 8 channels real time 2-D spectrograph and 8 sets CCD with 2K`2K; 2) EUV, 4 tubes of soft X-ray Telescope with 0.252 space resolution; 3) WBS, the wide Band Spectrometer with 256 channel from soft X-ray to Gamma-ray. 4) HAT, Ha and white light telescope; 5) SIRA, Solar and interplanetary Radio Spectrometer, with 100 KHZ-60 MHZ. The assembly and test will be introduced.

  4. Helioseismic Data Assimilation in Solar Dynamo Models

    CERN Document Server

    Muñoz-Jaramillo, Andrés; Martens, Petrus C H

    2008-01-01

    An essential ingredient in kinematic dynamo models is the velocity field within the solar convection zone. In particular, the differential rotation is now well constrained by helioseismic observations. Helioseismology also gives us information about the depth-dependence of the meridional circulation in the near-surface layers. The typical velocity inputs used in solar dynamo models, however, continue to be an analytic fit to the observed differential rotation and a theoretically constructed meridional flow profile that matches only the peak flow speed at the surface. Here we take the first steps towards realistic helioseismic data assimilation, by presenting methodologies for constructing differential rotation and meridional circulation profiles that more closely conform to the observational constraints currently available. We also present simulations driven by the assimilated rotation and four plausible profiles for the internal meridional circulation -- all of which match the helioseismically inferred near-...

  5. Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    This document is the Final Report of the Solar Energy System Installed at the First Solar Heated Office Building, One Solar Place, Dallas, Texas. The Solar System was designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 Solargenics, series 76, flat plate collectors with a total area of 1596 square feet. The solar loop circulates an ethylene glycol-water solution through the collectors into a hot water system heat exchanger. The hot water storage subsystem consists of a heat exchanger, two 2300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water fixtures. The building cold water system provides make-up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described. The system became operational July 11, 1979.

  6. Solar radiation practical modeling for renewable energy applications

    CERN Document Server

    Myers, Daryl Ronald

    2013-01-01

    Written by a leading scientist with over 35 years of experience working at the National Renewable Energy Laboratory (NREL), Solar Radiation: Practical Modeling for Renewable Energy Applications brings together the most widely used, easily implemented concepts and models for estimating broadband and spectral solar radiation data. The author addresses various technical and practical questions about the accuracy of solar radiation measurements and modeling. While the focus is on engineering models and results, the book does review the fundamentals of solar radiation modeling and solar radiation m

  7. The Development of a Roof Integrated Solar Hot Water System

    Energy Technology Data Exchange (ETDEWEB)

    Menicucci, David F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Energy Infrastructure and DER Dept.; Moss, Timothy A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Solar Technologies Dept.; Palomino, G. Ernest [Salt River Project (SRP), Tempe, AZ (United States)

    2006-09-01

    The Salt River Project (SRP), in conjunction with Sandia National Laboratories (SNL) and Energy Laboratories, Inc. (ELI), collaborated to develop, test, and evaluate an advanced solar water-heating product for new homes. SRP and SNL collaborated under a Department of Energy Cooperative Research and Development Agreement (CRADA), with ELI as SRP's industry partner. The project has resulted in the design and development of the Roof Integrated Thermal Siphon (RITH) system, an innovative product that features complete roof integration, a storage tank in the back of the collector and below the roofline, easy installation by homebuilders, and a low installed cost. SRP's market research guided the design, and the laboratory tests conducted at SNL provided information used to refine the design of field test units and indicated that the RITH concept is viable. ELI provided design and construction expertise and is currently configured to manufacture the units. This final report for the project provides all of the pertinent and available materials connected to the project including market research studies, the design features and development of the system, and the testing and evaluation conducted at SNL and at a model home test site in Phoenix, Arizona.

  8. Why Do People Stop Treating Contaminated Drinking Water with Solar Water Disinfection (SODIS)?

    Science.gov (United States)

    Tamas, Andrea; Mosler, Hans-Joachim

    2011-01-01

    Solar Water Disinfection (SODIS) is a simple method designed to treat microbiologically contaminated drinking water at household level. This article characterizes relapse behavior in comparison with continued SODIS use after a 7-month nonpromotion period. In addition, different subtypes among relapsers and continuers were assumed to diverge mainly…

  9. Why Do People Stop Treating Contaminated Drinking Water with Solar Water Disinfection (SODIS)?

    Science.gov (United States)

    Tamas, Andrea; Mosler, Hans-Joachim

    2011-01-01

    Solar Water Disinfection (SODIS) is a simple method designed to treat microbiologically contaminated drinking water at household level. This article characterizes relapse behavior in comparison with continued SODIS use after a 7-month nonpromotion period. In addition, different subtypes among relapsers and continuers were assumed to diverge mainly…

  10. Observations of Warm Water in Young Solar-System Analogs

    DEFF Research Database (Denmark)

    Persson, Magnus Vilhelm

    In star formation, water is an essential molecule. It affects the oxygen based chemistry, the physical conditions and energy balance in the protostellar envelope, and it is associated with the emergence of life as we know it. Ground based observations of water are hampered by the high amount...... dioxide). The amount of warm water is deduced and its origin is observationally constrained. With both isotopologues observed, the HDO/H2O ratio is deduced. This ratio is then compared to other sources, e.g., comets and the Earth’s ocean, to gain understanding of the origin of the water in our own solar...... of water vapor in Earth’s atmosphere. Many of the lines that are observable from the ground are masing in star forming regions, making it hard to deduce abundances. The few lines that are observable, and shown not be masing are isotopologues, like HDO and D2O, making the estimates of the main isotopologue...

  11. Numerical simulation of a parabolic trough solar collector for hot water and steam generation

    Science.gov (United States)

    Hachicha, Ahmed Amine

    2016-05-01

    Parabolic trough solar collectors (PTCs) are currently one of the most mature and prominent solar technology for the production of electricity. In order to reduce the electricity cost and improve the overall efficiency, Direct Steam generation (DSG) technology can be used for industrial heat process as well as in the solar fields for electricity production. In the last decades, this technology is experiencing an important development last decades and it is considered as one of the most feasible process for the next generation of power plants using PTCs. A numerical model based on Finite Volume Method (FVM) balance is presented to predict the thermal behavior of a parabolic trough solar collector used for hot water and steam generation. The realistic non-uniform solar flux is calculated in a pre-processing task and inserted to the general model. A numerical-geometrical method based on ray trace and FVM techniques is used to determine the solar flux distribution around the absorber tube with high accuracy.

  12. Solar production of industrial process hot water: Operation and evaluation of the Campbell Soup hot water solar facility

    Science.gov (United States)

    Kull, J. I.; Neimeyer, W. N.; Youngblood, S. B.

    1980-12-01

    The operation and evaluation of a solar hot water facility is summarized. The period of evaluation was for 12 months from October 1979 through September 1980. The objective of the work was to obtain additional, long term data on the operation and performance of the facility. Minor modifications to the facility were completed. The system was operated for 15 months, and 12 months of detailed data were evaluated. The facility was available for operation and of the time during the last 8 months of evaluation. A detailed description of the solar facility and of the operating experience is given, and a summary of system performance for the 12 month operation/evaluation period is presented. Recommendations for large scale solar facilities based on this project's experience are given, and an environmental impact assessment is provided.

  13. Development of a Greek solar map based on solar model estimations

    Science.gov (United States)

    Kambezidis, H. D.; Psiloglou, B. E.; Kavadias, K. A.; Paliatsos, A. G.; Bartzokas, A.

    2016-05-01

    The realization of Renewable Energy Sources (RES) for power generation as the only environmentally friendly solution, moved solar systems to the forefront of the energy market in the last decade. The capacity of the solar power doubles almost every two years in many European countries, including Greece. This rise has brought the need for reliable predictions of meteorological data that can easily be utilized for proper RES-site allocation. The absence of solar measurements has, therefore, raised the demand for deploying a suitable model in order to create a solar map. The generation of a solar map for Greece, could provide solid foundations on the prediction of the energy production of a solar power plant that is installed in the area, by providing an estimation of the solar energy acquired at each longitude and latitude of the map. In the present work, the well-known Meteorological Radiation Model (MRM), a broadband solar radiation model, is engaged. This model utilizes common meteorological data, such as air temperature, relative humidity, barometric pressure and sunshine duration, in order to calculate solar radiation through MRM for areas where such data are not available. Hourly values of the above meteorological parameters are acquired from 39 meteorological stations, evenly dispersed around Greece; hourly values of solar radiation are calculated from MRM. Then, by using an integrated spatial interpolation method, a Greek solar energy map is generated, providing annual solar energy values all over Greece.

  14. Decontamination of drinking water by direct heating in solar panels.

    Science.gov (United States)

    Fjendbo Jørgensen, A J; Nøhr, K; Sørensen, H; Boisen, F

    1998-09-01

    A device was developed for direct heating of water by solar radiation in a flow-through system of copper pipes. An adjustable thermostat valve prevents water below the chosen temperature from being withdrawn. The results show that it is possible to eliminate coliform and thermotolerant coliform bacteria from naturally contaminated river water by heating to temperatures of 65 degrees C or above. Artificial additions of Salmonella typhimurium, Streptococcus faecalis and Escherichia coli to contaminated river water were also inactivated after heating to 65 degrees C and above. The total viable count could be reduced by a factor of 1000. The heat-resistant bacteria isolated from the Mlalakuva River (Tanzania) were spore-forming bacteria which exhibited greater heat resistance than commonly used test bacteria originating from countries with colder climates. To provide a good safety margin it is recommended that an outlet water temperature of 75 degrees C be used. At that temperature the daily production was about 501 of decontaminated water per m2 of solar panel, an amount that could be doubled by using a heat exchanger to recycle the heat.

  15. Solar or UVA-Visible Photocatalytic Ozonation of Water Contaminants.

    Science.gov (United States)

    Beltrán, Fernando J; Rey, Ana

    2017-07-14

    An incipient advanced oxidation process, solar photocatalytic ozonation (SPO), is reviewed in this paper with the aim of clarifying the importance of this process as a more sustainable water technology to remove priority or emerging contaminants from water. The synergism between ozonation and photocatalytic oxidation is well known to increase the oxidation rate of water contaminants, but this has mainly been studied in photocatalytic ozonation systems with lamps of different radiation wavelength, especially of ultraviolet nature (UVC, UVB, UVA). Nowadays, process sustainability is critical in environmental technologies including water treatment and reuse; the application of SPO systems falls into this category, and contributes to saving energy and water. In this review, we summarized works published on photocatalytic ozonation where the radiation source is the Sun or simulated solar light, specifically, lamps emitting radiation to cover the UVA and visible light spectra. The main aspects of the review include photoreactors used and radiation sources applied, synthesis and characterization of catalysts applied, influence of main process variables (ozone, catalyst, and pollutant concentrations, light intensity), type of water, biodegradability and ecotoxicity, mechanism and kinetics, and finally catalyst activity and stability.

  16. Climate Sensitivity and Solar Cycle Response in Climate Models

    Science.gov (United States)

    Liang, M.; Lin, L.; Tung, K. K.; Yung, Y. L.

    2011-12-01

    Climate sensitivity, broadly defined, is a measure of the response of the climate system to the changes of external forcings such as anthropogenic greenhouse emissions and solar radiation, including climate feedback processes. General circulation models provide a means to quantitatively incorporate various feedback processes, such as water-vapor, cloud and albedo feedbacks. Less attention is devoted so far to the role of the oceans in significantly affecting these processes and hence the modelled transient climate sensitivity. Here we show that the oceanic mixing plays an important role in modifying the multi-decadal to centennial oscillations of the sea surface temperature, which in turn affect the derived climate sensitivity at various phases of the oscillations. The eleven-year solar cycle forcing is used to calibrate the response of the climate system. The GISS-EH coupled atmosphere-ocean model was run twice in coupled mode for more than 2000 model years, each with a different value for the ocean eddy mixing parameter. In both runs, there is a prominent low-frequency oscillation with a period of 300-500 years, and depending on the phase of such an oscillation, the derived climate gain factor varies by a factor of 2. The run with the value of the eddy ocean mixing parameter that is half that used in IPCC AR4 study has the more realistic low-frequency variability in SST and in the derived response to the known solar-cycle forcing.

  17. Deterministically Driven Avalanche Models of Solar Flares

    CERN Document Server

    Strugarek, Antoine; Joseph, Richard; Pirot, Dorian

    2014-01-01

    We develop and discuss the properties of a new class of lattice-based avalanche models of solar flares. These models are readily amenable to a relatively unambiguous physical interpretation in terms of slow twisting of a coronal loop. They share similarities with other avalanche models, such as the classical stick--slip self-organized critical model of earthquakes, in that they are driven globally by a fully deterministic energy loading process. The model design leads to a systematic deficit of small scale avalanches. In some portions of model space, mid-size and large avalanching behavior is scale-free, being characterized by event size distributions that have the form of power-laws with index values, which, in some parameter regimes, compare favorably to those inferred from solar EUV and X-ray flare data. For models using conservative or near-conservative redistribution rules, a population of large, quasiperiodic avalanches can also appear. Although without direct counterparts in the observational global st...

  18. Modelling and experimental validation of thin layer indirect solar drying of mango slices

    Energy Technology Data Exchange (ETDEWEB)

    Dissa, A.O.; Bathiebo, J.; Kam, S.; Koulidiati, J. [Laboratoire de Physique et de Chimie de l' Environnement (LPCE), Unite de Formation et de Recherche en Sciences Exactes et Appliquee (UFR/SEA), Universite de Ouagadougou, Avenue Charles de Gaulle, BP 7021 Kadiogo (Burkina Faso); Savadogo, P.W. [Laboratoire Sol Eau Plante, Institut de l' Environnement et de Recherches Agricoles, 01 BP 476, Ouagadougou (Burkina Faso); Desmorieux, H. [Laboratoire d' Automatisme et de Genie des Procedes (LAGEP), UCBL1-CNRS UMR 5007-CPE Lyon, Bat.308G, 43 bd du 11 Nov. 1918 Villeurbanne, Universite Claude Bernard Lyon1, Lyon (France)

    2009-04-15

    The thin layer solar drying of mango slices of 8 mm thick was simulated and experimented using a solar dryer designed and constructed in laboratory. Under meteorological conditions of harvest period of mangoes, the results showed that 3 'typical days' of drying were necessary to reach the range of preservation water contents. During these 3 days of solar drying, 50%, 40% and 5% of unbound water were eliminated, respectively, at the first, second and the third day. The final water content obtained was about 16 {+-} 1.33% d.b. (13.79% w.b.). This final water content and the corresponding water activity (0.6 {+-} 0.02) were in accordance with previous work. The drying rates with correction for shrinkage and the critical water content were experimentally determined. The critical water content was close to 70% of the initial water content and the drying rates were reduced almost at 6% of their maximum value at night. The thin layer drying model made it possible to simulate suitably the solar drying kinetics of mango slices with a correlation coefficient of r{sup 2} = 0.990. This study thus contributed to the setting of solar drying time of mango and to the establishment of solar drying rates' curves of this fruit. (author)

  19. Solar heating and hot water system installed at Arlington Raquetball Club, Arlington, Virginia

    Science.gov (United States)

    1981-01-01

    A solar space and water heating system is described. The solar energy system consists of 2,520 sq. ft. of flat plate solar collectors and a 4,000 gallon solar storage tank. The transfer medium in the forced closed loop is a nontoxic antifreeze solution (50 percent water, 50 percent propylene glycol). The service hot water system consists of a preheat coil (60 ft. of 1 1/4 in copper tubing) located in the upper third of the solar storage tank and a recirculation loop between the preheat coil and the existing electric water heaters. The space heating system consists of two separate water to air heat exchangers located in the ducts of the existing space heating/cooling systems. The heating water is supplied from the solar storage tank. Extracts from site files, specification references for solar modifications to existing building heating and hot water systems, and installation, operation and maintenance instructions are included.

  20. Solar water splitting in a molecular photoelectrochemical cell.

    Science.gov (United States)

    Alibabaei, Leila; Brennaman, M Kyle; Norris, Michael R; Kalanyan, Berç; Song, Wenjing; Losego, Mark D; Concepcion, Javier J; Binstead, Robert A; Parsons, Gregory N; Meyer, Thomas J

    2013-12-10

    Artificial photosynthesis and the production of solar fuels could be a key element in a future renewable energy economy providing a solution to the energy storage problem in solar energy conversion. We describe a hybrid strategy for solar water splitting based on a dye sensitized photoelectrosynthesis cell. It uses a derivatized, core-shell nanostructured photoanode with the core a high surface area conductive metal oxide film--indium tin oxide or antimony tin oxide--coated with a thin outer shell of TiO2 formed by atomic layer deposition. A "chromophore-catalyst assembly" 1, [(PO3H2)2bpy)2Ru(4-Mebpy-4-bimpy)Rub(tpy)(OH2)](4+), which combines both light absorber and water oxidation catalyst in a single molecule, was attached to the TiO2 shell. Visible photolysis of the resulting core-shell assembly structure with a Pt cathode resulted in water splitting into hydrogen and oxygen with an absorbed photon conversion efficiency of 4.4% at peak photocurrent.

  1. Hybrid solar cells from water-soluble polymers

    Directory of Open Access Journals (Sweden)

    James T. McLeskey

    2006-01-01

    Full Text Available We report on the use of a water-soluble, light-absorbing polythiophene polymer to fabricate novel photovoltaic devices. The polymer is a water-soluble thiophene known as sodium poly[2-(3-thienyl-ethoxy-4-butylsulfonate] or PTEBS. The intention is to take advantage of the properties of conjugated polymers (flexible, tunable, and easy to process and incorporate the additional benefits of water solubility (easily controlled evaporation rates and environmentally friendly. The PTEBS polythiophene has shown significant photovoltaic response and has been found to be effective for making solar cells. To date, solar cells in three different configurations have been produced: titanium dioxide (TiO2 bilayer cells, TiO2 bulk heterojunction solar cells, and carbon nanotubes (CNTs in bulk heterojunctions. The best performance thus far has been achieved with TiO2 bilayer devices. These devices have an open circuit voltage (Voc of 0.84V, a short circuit current (Jsc of 0.15 mA/cm2, a fill factor (ff of 0.91, and an efficiency (η of 0.15 %.

  2. Water Detected in the Terrestrial Zone of Extreme Solar Systems

    Science.gov (United States)

    Farihi, Jay

    2015-12-01

    Life as we know it requires water in contact with a rocky planetary surface. In the Solar System, water and other volatiles must have been delivered to a dry Earth from planetesimals, where asteroids in the outer main belt and Jupiter-Saturn region are excellent candidates. The first extrasolar analog of these rocky and water-rich planetesimals was reported between ESS II and III (Farihi et al. 2013, Science, 342, 218), and there is now evidence for additional examples. These results imply an underlying population of large, extrasolar planetesimals formed near a snow line, and suggesting a common mechanism for water delivery to habitable exoplanets.I will present Hubble, Spitzer, and ground-based data that demonstrate the confirmed and likely water-rich nature of exo-asteroids identified in a growing number of white dwarf planetary systems. These extreme solar systems formed and evolved around A-type (and similar) stars -- now firmly retired -- and the asteroid debris now orbits and pollutes the white dwarf with heavy elements, including oxygen in excess of that expected for oxide minerals. The abundance patterns are also carbon-poor, indicating the parent bodies were not icy planetesimals analogous to comets, but instead similar in overall composition to asteroids in the outer main belt.Importantly, these remnant exoplanetary systems imply architectures similar to the Solar System, where a giant planet exterior to a snow line perturbs rocky asteroids on the interior. Thus, they appear to share basic characteristics with HR 8799, Vega, Fomalhaut, and epsilon Eridani where two disks of debris are separated by giant planet(s), with one belt near the snow line. If such archictectures are as common as implied by polluted white dwarfs, then at least 30% of 1.2-3.0 Msun stars have both the tools and ingredentients for water delivery in their terrestrial planet zones.

  3. Solar Water Splitting and Nitrogen Fixation with Layered Bismuth Oxyhalides.

    Science.gov (United States)

    Li, Jie; Li, Hao; Zhan, Guangming; Zhang, Lizhi

    2017-01-17

    Hydrogen and ammonia are the chemical molecules that are vital to Earth's energy, environmental, and biological processes. Hydrogen with renewable, carbon-free, and high combustion-enthalpy hallmarks lays the foundation of next-generation energy source, while ammonia furnishes the building blocks of fertilizers and proteins to sustain the lives of plants and organisms. Such merits fascinate worldwide scientists in developing viable strategies to produce hydrogen and ammonia. Currently, at the forefronts of hydrogen and ammonia syntheses are solar water splitting and nitrogen fixation, because they go beyond the high temperature and pressure requirements of methane stream reforming and Haber-Bosch reaction, respectively, as the commercialized hydrogen and ammonia production routes, and inherit the natural photosynthesis virtues that are green and sustainable and operate at room temperature and atmospheric pressure. The key to propelling such photochemical reactions lies in searching photocatalysts that enable water splitting into hydrogen and nitrogen fixation to make ammonia efficiently. Although the past 40 years have witnessed significant breakthroughs using the most widely studied TiO2, SrTiO3, (Ga1-xZnx)(N1-xOx), CdS, and g-C3N4 for solar chemical synthesis, two crucial yet still unsolved issues challenge their further progress toward robust solar water splitting and nitrogen fixation, including the inefficient steering of electron transportation from the bulk to the surface and the difficulty of activating the N≡N triple bond of N2. This Account details our endeavors that leverage layered bismuth oxyhalides as photocatalysts for efficient solar water splitting and nitrogen fixation, with a focus on addressing the above two problems. We first demonstrate that the layered structures of bismuth oxyhalides can stimulate an internal electric field (IEF) that is capable of efficiently separating electrons and holes after their formation and of precisely channeling

  4. Using Solar Hot Water to Address Piping Heat Losses in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Springer, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Seitzler, Matt [National Renewable Energy Lab. (NREL), Golden, CO (United States); Backman, Christine [National Renewable Energy Lab. (NREL), Golden, CO (United States); Weitzel, Elizabeth [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-10-01

    Solar thermal water heating is most cost effective when applied to multifamily buildings and some states offer incentives or other inducements to install them. However, typical solar water heating designs do not allow the solar generated heat to be applied to recirculation losses, only to reduce the amount of gas or electric energy needed for hot water that is delivered to the fixtures. For good reasons, hot water that is recirculated through the building is returned to the water heater, not to the solar storage tank. The project described in this report investigated the effectiveness of using automatic valves to divert water that is normally returned through the recirculation piping to the gas or electric water heater instead to the solar storage tank. The valves can be controlled so that the flow is only diverted when the returning water is cooler than the water in the solar storage tank.

  5. Using Solar Hot Water to Address Piping Heat Losses in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Springer, David [Alliance for Residential Building Innovation, Davis, CA (United States); Seitzler, Matt [Alliance for Residential Building Innovation, Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation, Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation, Davis, CA (United States)

    2015-10-01

    Solar thermal water heating is most cost effective when applied to multifamily buildings and some states offer incentives or other inducements to install them. However, typical solar water heating designs do not allow the solar generated heat to be applied to recirculation losses, only to reduce the amount of gas or electric energy needed for hot water that is delivered to the fixtures. For good reasons, hot water that is recirculated through the building is returned to the water heater, not to the solar storage tank. The project described in this report investigated the effectiveness of using automatic valves to divert water that is normally returned through the recirculation piping to the gas or electric water heater instead to the solar storage tank. The valves can be controlled so that the flow is only diverted when the returning water is cooler than the water in the solar storage tank.

  6. Building America Case Study: Addressing Multifamily Piping Losses with Solar Hot Water, Davis, California

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-01

    Solar thermal water heating is most cost effective when applied to multifamily buildings and some states offer incentives or other inducements to install them. However, typical solar water heating designs do not allow the solar generated heat to be applied to recirculation losses, only to reduce the amount of gas or electric energy needed for hot water that is delivered to the fixtures. For good reasons, hot water that is recirculated through the building is returned to the water heater, not to the solar storage tank. The project described in this report investigated the effectiveness of using automatic valves to divert water that is normally returned through the recirculation piping to the gas or electric water heater instead to the solar storage tank. The valves can be controlled so that the flow is only diverted when the returning water is cooler than the water in the solar storage tank.

  7. Solution transformation of Cu₂O into CuInS₂ for solar water splitting.

    Science.gov (United States)

    Luo, Jingshan; Tilley, S David; Steier, Ludmilla; Schreier, Marcel; Mayer, Matthew T; Fan, Hong Jin; Grätzel, Michael

    2015-02-11

    Though Cu2O has demonstrated high performance as a photocathode for solar water splitting, its band gap is too large for efficient use as the bottom cell in tandem configurations. Accordingly, copper chalcopyrites have recently attracted much attention for solar water splitting due to their smaller and tunable band gaps. However, their fabrication is mainly based on vacuum evaporation, which is an expensive and energy consuming process. Here, we have developed a novel and low-cost solution fabrication method, and CuInS2 was chosen as a model material due to its smaller band gap compared to Cu2O and relatively simple composition. The nanostructured CuInS2 electrodes were synthesized at low temperature in crystalline form by solvothermal treatment of electrochemically deposited Cu2O films. Following the coating of overlayers and decoration with Pt catalyst, the as-fabricated CuInS2 electrode demonstrated water splitting photocurrents of 3.5 mA cm(-2) under simulated solar illumination. To the best of our knowledge, this is the highest performance yet reported for a solution-processed copper chalcopyrite electrode for solar water splitting. Furthermore, the electrode showed good stability and had a broad incident photon-to-current efficiency (IPCE) response to wavelengths beyond 800 nm, consistent with the smaller bandgap of this material.

  8. Solar Water disinfection for human consumption; Desinfeccao Solar de Agua para consumo humano

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, A.; Vilar, V.; Boaventura, R.

    2008-07-01

    In this work a pilot plant with 0.59 m{sup 2} of solar collectors has been used for studying the disinfection by solar photo catalysis of waters contaminated with Escherichia coli, Enterococcus faecal or humic acids. the results obtained showed a higher resistance of Enterococcus to the photo catalytic treatment ([TiO{sub 2}] =50 mg/L) compared with E. coli, being necessary a higher amount of UV energy for killing them, using an initial bacteria concentration of 1x10{sup 5} CFU/mL. For the treatment of water contaminated with humic acids was applied 20 kJ UV/L to reduce the TOC concentration from 6.9 mg/L to 1 mg/L. (Author)

  9. Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Blair, N.; Dobos, A.

    2010-10-01

    Solar Advisor Model (SAM) is a free software package made available by the National Renewable Energy Laboratory (NREL), Sandia National Laboratory, and the US Department of Energy. SAM contains hourly system performance and economic models for concentrating solar power (CSP) systems, photovoltaic, solar hot-water, and generic fuel-use technologies. Versions of SAM prior to 2010 included only the parabolic trough model based on Excelergy. This model uses top-level empirical performance curves to characterize plant behavior, and thus is limited in predictive capability for new technologies or component configurations. To address this and other functionality challenges, a new trough model; derived from physical first principles was commissioned to supplement the Excelergy-based empirical model. This new 'physical model' approaches the task of characterizing the performance of the whole parabolic trough plant by replacing empirical curve-fit relationships with more detailed calculations where practical. The resulting model matches the annual performance of the SAM empirical model (which has been previously verified with plant data) while maintaining run-times compatible with parametric analysis, adding additional flexibility in modeled system configurations, and providing more detailed performance calculations in the solar field, power block, piping, and storage subsystems.

  10. Predictive Control Applied to a Solar Desalination Plant Connected to a Greenhouse with Daily Variation of Irrigation Water Demand

    Directory of Open Access Journals (Sweden)

    Lidia Roca

    2016-03-01

    Full Text Available The water deficit in the Mediterranean area is a known matter severely affecting agriculture. One way to avoid the aquifers’ exploitation is to supply water to crops by using thermal desalination processes. Moreover, in order to guarantee long-term sustainability, the required thermal energy for the desalination process can be provided by solar energy. This paper shows simulations for a case study in which a solar multi-effect distillation plant produces water for irrigation purposes. Detailed models of the involved systems are the base of a predictive controller to operate the desalination plant and fulfil the water demanded by the crops.

  11. Solar Water Heating with Low-Cost Plastic Systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-01

    Federal buildings consumed over 392,000 billion Btu of site delivered energy for buildings during FY 2007 at a total cost of $6.5 billion. Earlier data indicate that about 10% of this is used to heat water.[2] Targeting energy consumption in Federal buildings, the Energy Independence and Security Act of 2007 (EISA) requires new Federal buildings and major renovations to meet 30% of their hot water demand with solar energy, provided it is cost-effective over the life of the system. In October 2009, President Obama expanded the energy reduction and performance requirements of EISA and its subsequent regulations with his Executive Order 13514.

  12. Modeling Anomalous Hysteresis in Perovskite Solar Cells.

    Science.gov (United States)

    van Reenen, Stephan; Kemerink, Martijn; Snaith, Henry J

    2015-10-01

    Organic-inorganic lead halide perovskites are distinct from most other semiconductors because they exhibit characteristics of both electronic and ionic motion. Accurate understanding of the optoelectronic impact of such properties is important to fully optimize devices and be aware of any limitations of perovskite solar cells and broader optoelectronic devices. Here we use a numerical drift-diffusion model to describe device operation of perovskite solar cells. To achieve hysteresis in the modeled current-voltage characteristics, we must include both ion migration and electronic charge traps, serving as recombination centers. Trapped electronic charges recombine with oppositely charged free electronic carriers, of which the density depends on the bias-dependent ion distribution in the perovskite. Our results therefore show that reduction of either the density of mobile ionic species or carrier trapping at the perovskite interface will remove the adverse hysteresis in perovskite solar cells. This gives a clear target for ongoing research effort and unifies previously conflicting experimental observations and theories.

  13. Solar models with accretion. I. Application to the solar abundance problem

    CERN Document Server

    Serenelli, Aldo M; Pena-Garay, Carlos

    2011-01-01

    We generate new standard solar models using newly analyzed nuclear fusion cross sections and present results for helioseismic quantities and solar neutrino fluxes. We discuss the status of the solar abundance problem and investigate whether nonstandard solar models with accretion from the protoplanetary disk might alleviate the problem. We examine a broad range of possibilities, analyzing both metal-enriched and metal-depleted accretion models and exploring three scenarios for the timing of the accretion. Only partial solutions are found: one can bring either the depth of the convective zone or the surface helium abundance into agreement with helioseismic results, but not both simultaneously. In addition, detailed results for solar neutrino fluxes show that neutrinos are a competitive source of information about the solar core and can help constrain possible accretion histories of the Sun. Finally, we briefly discuss how measurements of solar neutrinos from the CN-cycle could shed light on the interaction bet...

  14. Model for computation of solar fraction in a single-slope solar still

    Energy Technology Data Exchange (ETDEWEB)

    Madhlopa, A.; Johnstone, C. [Energy Systems Research Unit, Department of Mechanical Engineering, University of Strathclyde, 75 Montrose Street, Glasgow G1 1XJ (United Kingdom)

    2009-06-15

    A new model that calculates the distribution of solar radiation inside a single-slope solar still has been proposed. In this model, the solar fraction on a vertical surface is divided into beam and diffuse parts and the optical view factors of surfaces inside the still are taken into account. To validate the model, outdoor tests of a conventional solar still were conducted under different weather conditions at the University of Strathclyde. The proposed model is compared with the previous one. It is found that the beam solar fraction is affected by both the geometry of the solar still and position of the sun in the sky. In contrast, the diffuse solar fraction is only dependent on the geometry of the solar distiller. The present model exhibited a lower root mean square error than that of the previous model. It appears that splitting the solar fraction into beam and diffuse parts improves the accuracy of modelling the performance of a single-slope solar still. (author)

  15. Role of Solar Water Heating in Multifamily Zero Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Williamson, James [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2016-04-08

    Solar domestic hot water (SDHW) systems have been installed on buildings for decades, but because of relatively high costs they have not achieved significant market penetration in most of the country. As more buildings move towards zero net energy consumption, however, many designers and developers are looking more closely at SDHW. In multifamily buildings especially, SDHW may be more practical for several reasons: 1) When designing for zero net energy consumption, solar water heating may be part of the lowest cost approach to meet water heating loads; 2) Because of better scale, SDHW systems in multifamily buildings cost significantly less per dwelling than in single-family homes; 3) Many low-load buildings are moving away from fossil fuels entirely. SDHW savings are substantially greater when displacing electric resistance water heating; and 4) In addition to federal tax incentives, some states have substantial financial incentives that dramatically reduce the costs (or increase the benefits) of SDHW systems in multifamily buildings. With support from the U.S. DOE Building America program, the Consortium for Advanced Residential Buildings (CARB) worked with a developer in western Massachusetts to evaluate a SDHW system on a 12-unit apartment building. Olive Street Development completed construction in spring of 2014, and CARB has been monitoring performance of the water heating systems since May 2014.

  16. Building America Case Study: Solar Water Heating in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    R. Aldrich and J. Williamson

    2016-05-01

    Solar domestic hot water (SDHW) systems have been installed on buildings for decades, but because of relatively high costs they have not achieved significant market penetration in most of the country. As more buildings move towards zero net energy consumption, however, many designers and developers are looking more closely at SDHW. In multifamily buildings especially, SDHW may be more practical for several reasons: (1) When designing for zero net energy consumption, solar water heating may be part of the lowest cost approach to meet water heating loads. (2.) Because of better scale, SDHW systems in multifamily buildings cost significantly less per dwelling than in single-family homes. (3) Many low-load buildings are moving away from fossil fuels entirely. SDHW savings are substantially greater when displacing electric resistance water heating. (4) In addition to federal tax incentives, some states have substantial financial incentives that dramatically reduce the costs (or increase the benefits) of SDHW systems in multifamily buildings. With support form the U.S. DOE Building America program, the Consortium for Advanced Residential Buildings (CARB) worked with a developer in western Massachusetts to evaluate a SDHW system on a 12-unit apartment building. Olive Street Development completed construction in spring of 2014, and CARB has been monitoring performance of the water heating systems since May 2014.

  17. Solar Electric Bicycle Body Modeling and Simulation

    Directory of Open Access Journals (Sweden)

    Zhikun Wang

    2013-10-01

    Full Text Available A new solar electric bicycle design and study were carried out on in this paper. Application of CAD technology to establish three-dimension geometric model, using the kinetic analysis on the frame and other parts for numerical simulation and static strength analysis for the vehicle model design, virtual assembly, complete frame dynamics analysis and vibration analysis, with considering other factors, first on the frame structure improvement, second on security of design calculation analysis and comparison, finally get the ideal body design.

  18. Feasibility evaluation solar heated textile process water. Volume II. Appendices. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hester, J. C.; Beard, J. N.; Robinson, G. F.; Harnett, R. M.

    1977-02-01

    The general objectives of this study are to determine the technical and economic feasibility of the use of solar energy for heating waters in the textile industry and to develop a plan for efforts beyond this feasibility study phase. Specific objectives include (1) determine the industry requirements for heated process water, (2) assess particular schemes and their economic impact, (3) study the total cost environment for solar water heating in this industry, and (4) recommend future experiments. This volume contains the appendices: (A) fiber distribution and end use data; (B) computer model description for textile plant energy balances; (C) computer model description to generate local solar potential; (D) computer model description for system synthesis and analysis; (E) computer model to determine pressure drop, flow distribution and plumbing components; (F) area requirement plots for various use rates, temperature levels, seasons, orientations and collector types for textile operations; (G) computer model description of economic variables for COSMO1 and COSMO2; (H) rate of return plots for various textile applications and energy cost scenerios; and (I) data base for efficiency curves for six collector types. (WHK)

  19. Solar Photocatalytic decomposition of pentachlorophenol in water; Descomposicion de pentaclorofenol en agua mediante fotocatalisis solar

    Energy Technology Data Exchange (ETDEWEB)

    Malato Rodriguez, S.

    1997-09-01

    In recent years, research in new water purification methods has focused on processes that chemically destroy the pollutants. During the last two decades, several laboratories have been using heterogeneous photocatalysis for the decomposition of very persistent organic substances dissolved in water using different kinds of lamps as the source of illumination and reactors designed to be illuminated by them. Since 1990, several research programs in the United States and the European Union have addressed the technological development necessary to use solar energy as the light source. The Plataforma Solar de Almeria (PSA) in the co-ordinator of several of the European programs, which has enabled it to install the facility used for the work presented here. This thesis focuses on :(i) the design, installation and start-up of the first pilot plant that allowed these projects to be undertaken at the PSA, (ii) the preliminary characterisation studies necessary to evaluate the data from experiments carried out in the plant and (iii) tests with a known pollutant in order to find out the pilot plant response to variation of different parameters selected as determinants in laboratory experimentation. The photocatalytic system used for this was: pentachlorophenol (CAS 87-86-5) as typical contaminant, ultraviolet made up to twelve parabolic-trough solar collectors (384 m``2), modified for photochemical use, 2500 L of water with tens of mg L``-1 of pollutant were treated (maximum). (Author)

  20. A Solar Model with g-Modes

    Science.gov (United States)

    Wolff, Charles L.; Niemann, Hasso (Technical Monitor)

    2002-01-01

    Good evidence is assembled showing that the Suit's core arid surface vary on time scales from a month to a decade arid that a number of scales are similar. The most plausible source for numerous long time scales and periodicities is long-lived global oscillations. This suggests g-modes (oscillations restored mainly by buoyancy) because they particularly affect the core and base of the convective envelope, which then indirectly modulates the surface. Also, standing g-modes have rotational properties that match many observed periodicities. But the standard solar model (SSM) has a static core and excites few if any g-modes. making new interior structures worth exploring. The model outlined here assumes two well mixed shells near 0.18 and 0.68 R, (13 = solar radius) where sound speed data shows sharp deviations from the SSM. Mixing is sustained by flows driven by the oscillations. The shells form a cavity that excludes g-modes from their main damping region below 0.1 R, assisting their net excitation and increasing their oscillation periods by at least a factor of two and probably much more. In terms of the solar luminosity L, the modes transport up through the cavity a power approx. 0.004 L as a lower limit and 0.11 L as all upper limit. The modes dissipate energy in the outer shell and cool the inner shell, asymmetrically in each case, and this stimulates occasional convective events whose response time is typically 0.8 years longer near the inner shell. Such events cool the core and reduce neutrino flux while heating the envelope and increasing solar activity. This gives a physical basis for a well mixed Sun with low neutrino flux and basis for the observed anticorrelation and lag of neutrino behind surface activity.

  1. A comparison of diesel, biodiesel and solar PV-based water pumping systems in the context of rural Nepal

    DEFF Research Database (Denmark)

    Parajuli, Ranjan; Pokharel, Govind Raj; Østergaard, Poul Alberg

    2014-01-01

    using petro-diesel, jatropha-based biodiesel and solar photovoltaic pumps. The technical system design consists of system sizing of prime mover (engine, solar panel and pumps) and estimation of reservoir capacity, which are based on the annual aggregate water demand modelling. With these investigations...... area, the levelised cost of pumping 1 L of water is higher than that of a solar pump and even higher when compared with diesel, if the seed yield per plant is less than 2 kg and without subsidy on the investment cost of cultivation and processing. With the productivity of 2.5 kg/plant, a biodiesel......-based system is more attractive than that of the diesel-based pump, but still remains more expensive than that of solar pump. From the technical perspective (reliability and easiness in operation) and economic evaluation of the technical alternatives, solar pumping system is found to be the most viable...

  2. Forced-circulation solar water heater using a solar battery; Taiyo denchi wo mochiita kyosei junkanshiki taiyonetsu onsuiki

    Energy Technology Data Exchange (ETDEWEB)

    Asai, S.; Mizuno, T. [Yazaki Resources Co. Ltd., Shizuoka (Japan)

    1996-10-27

    For the purpose of satisfying demands for qualitative improvement on tapwater temperature and pressure, an indirect-type solar water heater using solar cells, in which a closed type hot water storage tank connected directly to the water supply is integrated with a solar collector, was examined for its characteristics and performance. The heat collecting medium is a water solution of polypropylene glycol, which circulates through the solar collector pump, cistern, solar collector, and heat exchanger (hot water storage tank). The results of the test are summarized below. When comparison is made between the two solar collector pump control methods, the solar cells direct connection method and the differential thermo method utilizing temperature difference between the solar collector and the hot water storage tank, they are alike in collecting heat on clear days, but on cloudy days the latter collects 5% more than the former. In winter, when the heat exchanger heat transfer area is 0.4m{sup 2} large, a further increase in the area improves but a little the heat collecting efficiency. An increase in the medium flow rate and temperature, or in the Reynolds number, enhances the heat collecting efficiency. 13 figs., 6 tabs.

  3. CFD Study of Fluid Flow in an All-glass Evacuated Tube Solar Water Heater

    DEFF Research Database (Denmark)

    Ai, Ning; Fan, Jianhua; Li, Yumin

    2008-01-01

    Abstract: The all-glass evacuated tube solar water heater is one of the most widely used solar thermal technologies. The aim of the paper is to investigate fluid flow in the solar water heater by means of computational fluid dynamics (CFD). The investigation was carried out with a focus...

  4. Modeling the Effects of Solar Cell Attitude Distribution on Optical Cross Section for Solar Panel Simulations

    Science.gov (United States)

    Feirstine, K.; Bush, K.; Crosher, C.; Klein, M.; Bowers, D.; Wellems, D.; Duggin, M.; Vaughn, L.

    2012-09-01

    The Air Force Research Laboratory (AFRL) Time-domain Analysis Simulation for Advanced Tracking (TASAT) was used to explore the variation of Optical Cross Section (OCS) with glint angle for a solar panel with different solar cell attitude distribution statistics. Simulations were conducted using a 3D model of a solar panel with various solar cell tip and tilt distribution statistics. Modeling a solar panel as a single sheet of "solar cell" material is not appropriate for OCS glint studies. However, modeling each individual solar cell on the panel, the tips and tilts of which come from a distribution of specified statistics (distribution type, mean, and standard deviation), accurately captures the solar panel OCS with glint angle. The objective of the simulations was to vary the glint measurement angle about the maximum glint position of the solar panel and observe the variations in OCS with angle for a bi-static illumination condition. OCS was calculated relative to the simulated scattering of a Spectralon material in the glint orientation. Results show the importance of solar cell attitude distribution statistics in modeling the OCS observed for a solar panel.

  5. Material cycling solar system modeled ecosystem; Seitaikei wo model to shita busshitsu junkangata solar system

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M. [Hachinohe Institute of Technology, Aomori (Japan)

    1996-10-27

    It is proposed to establish an integrated system close to a natural ecosystem for an industrial complex, taking that in Hachinohe City, Aomori Pref. as the conceptual site. It is a system in which materials are recycled by solar energy and industrial waste heat for a complex food industry. The conceptual site, although blessed with various marine products, are sometimes attacked by cold weather. Waste heat from a 250,000kW power plant, if transported by EHD heat pipes to the site, could provide roughly 400 times the heat required for production of agricultural and marine products, such as cabbages and fish meat. The waste heat, coupled with solar energy, should solve the problems resulting from hot waste water, if they could be utilized for the industrial purposes. The food industrial site that produces agricultural and marine products is considered to be suited as the center of the solar industrial complex incorporating farms. 5 refs., 3 figs.

  6. Experimental studies on PCM filled Flat Plate Solar Water Heater without and with Fresnel lens glazing

    Directory of Open Access Journals (Sweden)

    R. Sivakumar

    2016-07-01

    Full Text Available Flat Plate Solar Water Heater (FPSWH is commonly used to harvest solar energy. Solar concentration techniques help to achieve higher temperatures of energy. The aim of this article is to compare the performance of a Fresnel lens glazed Flat Plate Solar Water Heater with Phase Change Material (PCM with that provided with an ordinary glazing. The effect of solar concentration using Fresnel lens on energy storage in PCM and heat gained by water are studied and compared with that having an ordinary glazing. Experiments showed 47% improvements in the heat gained by water.

  7. Development of a new solar thermal engine system for circulating water for aeration

    Energy Technology Data Exchange (ETDEWEB)

    Kerdchang, Pongsakorn; Win, Maung Maung; Teekasap, Sombat [South-East Asia Univ., Building Scientific Research Center, Bangkok (Thailand); Hirunlabh, Jongjit; Khedari, Joseph [King Mongkut' s Univ. of Technology Thonburi, Bangkok (Thailand); Zeghmati, Belkacem [Perpignan Univ., Centre d' Etudes Fondamentales, Groupe de Mecanique Acoustique et Instrumentation, Perpignan, 66 (France)

    2005-04-01

    This paper presents a numerical study about the performance of a Beta Stirling solar thermal engine system. This system is composed of a solar collector box connected to a regenerator hydraulic system and a transmitting power system. The objective of the system is to offer a new alternative to help solving stagnant water pollution in hot countries like Thailand by circulating water in canals, lakes, ponds etc. for aeration using solar energy. The purpose of this study is to determine the power output and actual heat transfer on the performance of the solar thermal engine. The solar thermal engine is analyzed using a mathematical model based on the first law of thermodynamics for processes with finite speed, with particular attention to the energy balance at the receiver. The result of calculations showed that the regenerator volume and phase angle must be chosen carefully to fulfill the requirement that total fluid mass in the system is constant and to obtain maximum power output throughout the day. (Author)

  8. Use of solar energy in the treatment of water contaminated with phenol by photochemical processes

    Directory of Open Access Journals (Sweden)

    K. R. B. Nogueira

    2008-12-01

    Full Text Available The solar driven photo-Fenton process for treating water containing phenol as a contaminant has been evaluated by means of pilot-scale experiments with a parabolic trough solar reactor (PTR. The effects of Fe(II (0.04-1.0 mmol L-1, H2O2 (7-270 mmol L-1, initial phenol concentration (100 and 500 mg C L-1, solar radiation, and operation mode (batch and fed-batch on the process efficiency were investigated. More than 90% of the dissolved organic carbon (DOC was removed within 3 hours of irradiation or less, a performance equivalent to that of artificially-irradiated reactors, indicating that solar light can be used either as an effective complementary or as an alternative source of photons for the photo-Fenton degradation process. A non-linear multivariable model based on a neural network was fit to the experimental results of batch-mode experiments in order to evaluate the relative importance of the process variables considered on the DOC removal over the reaction time. This included solar radiation, which is not a controlled variable. The observed behavior of the system in batch-mode was compared with fed-batch experiments carried out under similar conditions. The main contribution of the study consists of the results from experiments under different conditions and the discussion of the system behavior. Both constitute important information for the design and scale-up of solar radiation-based photodegradation processes.

  9. Development of Hot Water Solar Oven for Low Temperature Thermal Processes

    Directory of Open Access Journals (Sweden)

    Segun R. BELLO

    2009-07-01

    Full Text Available The most useful form of the Hottel-Whiller-Bliss generalized performance equations for flat plate collector utilizing heat removal factor and loss coefficients is used to model a solar oven- water heating system for low thermal process application. The water heating system was designed, tested and evaluated with a daily collector efficiency of 51.82%, an average daily solar radiation of 689.23 (w/ºc per day and a useful gain by collector of 563.85 (w/ºc. Loss in collector is 116.39 (w/ºc and total average daily heat gain by water in collector is 292.26 (w/ºc. Average Daily storage heat capacity of 582.83 (KJ and the daily convected heat delivered to test chamber is 147.07 (KJ. The overall System efficiency of 25.24% was obtained.

  10. Contribution to the modeling of solar spicules

    CERN Document Server

    Tavabi, E; Ajabshirizadeh, A

    2011-01-01

    Solar limb and disc spicule quasi- periodic motions have been reported for a long time, strongly suggesting that they are oscillating. In order to clear up the origin and possibly explain some solar limb and disc spicule quasi-periodic recurrences produced by overlapping effects, we present a simulation model assuming quasi- random positions of spicules. We also allow a set number of spicules with different physical properties (such as: height, lifetime and tilt angle as shown by an individual spicule) occurring randomly. Results of simulations made with three different spatial resolutions of the corresponding frames and also for different number density of spicules, are analyzed. The wavelet time/frequency method is used to obtain the exact period of spicule visibility. Results are compared with observations of the chromosphere from i/ the Transition Region and Coronal Explorer (TRACE) filtergrams taken at 1600 angstrom, ii/ the Solar Optical Telescope (SOT) of Hinode taken in the Ca II H-line and iii/ the S...

  11. Nonlinear Dynamic Model Explains The Solar Dynamic

    Science.gov (United States)

    Kuman, Maria

    Nonlinear mathematical model in torus representation describes the solar dynamic. Its graphic presentation shows that without perturbing force the orbits of the planets would be circles; only perturbing force could elongate the circular orbits into ellipses. Since the Hubble telescope found that the planetary orbits of other stars in the Milky Way are also ellipses, powerful perturbing force must be present in our galaxy. Such perturbing force is the Sagittarius Dwarf Galaxy with its heavy Black Hole and leftover stars, which we see orbiting around the center of our galaxy. Since observations of NASA's SDO found that magnetic fields rule the solar activity, we can expect when the planets align and their magnetic moments sum up, the already perturbed stars to reverse their magnetic parity (represented graphically as periodic looping through the hole of the torus). We predict that planets aligned on both sides of the Sun, when their magnetic moments sum-up, would induce more flares in the turbulent equatorial zone, which would bulge. When planets align only on one side of the Sun, the strong magnetic gradient of their asymmetric pull would flip the magnetic poles of the Sun. The Sun would elongate pole-to-pole, emit some energy through the poles, and the solar activity would cease. Similar reshaping and emission was observed in stars called magnetars and experimentally observed in super-liquid fast-spinning Helium nanodroplets. We are certain that NASA's SDO will confirm our predictions.

  12. Verification of high-speed solar wind stream forecasts using operational solar wind models

    Science.gov (United States)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.; Nikolic, Ljubomir; Vennerstrom, Susanne; Schöngassner, Florian; Hofmeister, Stefan J.

    2016-07-01

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation between the coronal hole area observed in Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images and solar wind properties at the near-Earth environment, the WSA model establishes a link between properties of the open magnetic field lines extending from the photosphere to the corona and the background solar wind conditions. We found that both solar wind models are capable of predicting the large-scale features of the observed solar wind speed (root-mean-square error, RMSE ≈100 km/s) but tend to either overestimate (ESWF) or underestimate (WSA) the number of high-speed solar wind streams (threat score, TS ≈ 0.37). The predicted high-speed streams show typical uncertainties in the arrival time of about 1 day and uncertainties in the speed of about 100 km/s. General advantages and disadvantages of the investigated solar wind models are diagnosed and outlined.

  13. Solar-Based Fuzzy Intelligent Water Sprinkle System

    Directory of Open Access Journals (Sweden)

    Riza Muhida

    2012-03-01

    Full Text Available A solar-based intelligent water sprinkler system project that has been developed to ensure the effectiveness in watering the plant is improved by making the system automated. The control system consists of an electrical capacitance soil moisture sensor installed into the ground which is interfaced to a controller unit of Motorola 68HC11 Handy board microcontroller. The microcontroller was programmed based on the decision rules made using fuzzy logic approach on when to water the lawn. The whole system is powered up by the solar energy which is then interfaced to a particular type of irrigation timer for plant fertilizing schedule and rain detector through a simple design of rain dual-collector tipping bucket. The controller unit automatically disrupted voltage signals sent to the control valves whenever irrigation was not needed. Using this system we combined the logic implementation in the area of irrigation and weather sensing equipment, and more efficient water delivery can be made possible. 

  14. Evaluation of Solar Photosensitised River Water Treatment in the Caribbean

    Directory of Open Access Journals (Sweden)

    K. Tota-Maharaj

    2013-01-01

    Full Text Available An economical supply of hygienic potable water is one of the most pressing public health issues facing developing countries in the Caribbean region today. This project investigates the performance of a novel solar photochemical reactor for disinfecting river water. The prototype photochemical reactor was designed, constructed, and tested for the microbiological degradation of faecal coliform present in River Water. The experiments evaluated the efficacy of two photosensitive dyes (malachite green and methylene blue as agents for detoxification with concentrations ranging from 0.5 to 3.0 mg/L. The photochemical reactor operated in a single-pass mode and compared the disinfection rates with direct photolysis. The photosensitizers showed a high efficacy rate using natural sunlight with microbial reduction ranging from 97 to 99% for concentrations as low as 0.5 mg/L of dye. The sensitizers were found to be photobleaching and were very effective at lower concentrations (0.01. Post-solar disinfection included the use of a coconut fiber filter which polished the water removing residual dye concentrations and bacterial contaminants.

  15. Two-component model of solar plages

    Institute of Scientific and Technical Information of China (English)

    LI; Jianping(李建平); DING; Mingde(丁明德); FANG; Cheng(方成)

    2002-01-01

    By use of the 2-m Mcmath-Pierce telescope at Kitt Peak, the high-quality spectra of a plage with moderate brightness near the center of solar disk were obtained. The data include seven spectral lines, which are Hα, Hβ, CaII H and K lines and the infrared triplet. With the consideration of fine structures of solar plages, a two-component atmospheric model is constructed by keeping the cool component to be the quiet atmosphere. Three cases of the hot component are given for different filling factors where the temperature and density distribution are adjusted in order to reproduce the seven observed spectral profiles. We also briefly discuss the influence of the column density at the base of the corona, m0, and the macro-turbulent velocity on the required filling factor and computed profiles. The two-component model is compared with precious one-component semi-empirical models. The limitation of the model is pointed out and further improvement is indicated.

  16. Remote sensing of water vapor within the solar spectrum

    Science.gov (United States)

    Bartsch, Barbara; Bakan, Stephan; Fischer, Juergen

    1995-01-01

    Due to the great importance of atmospheric water vapor for weather and climate, much effort is devoted to remote sensing of atmospheric water vapor. The detection over water is well established, while the situation over land surface is worse. Therefore, a new method is developed to derive the total atmospheric water vapor content over land surfaces even for higher aerosol contents with the aid of backscattered solar radiances. Numerous radiative transfer simulations with a matrix operator code of vertically backscattered solar radiance were carried out for different vertically stratified atmospheres. The resolution of 1.7 nm in the wavelength range from 700 to 1050 nm was adopted to the resolution of our multichannel spectrometer OVID (Optical Visible and near Infrared Detector). Various atmospheric conditions were chosen, which were defined by variable input parameters of: (a) vertical profiles of temperature, pressure, and water vapor, (b) total water vapor content, (c) aerosols, (d) surface reflectance, and (e) sun zenith angle. Clouds were not taken into account. From the evaluation of these theoretical calculations it can be concluded that this technique allows the detection of total atmospheric water vapor content over land surfaces with an error of less than 10%. This result is important with regard to future measurements planed with the MERIS imaging spectrometer on board the european satellite ENVISAT, which will be launched in 1998. In addition to these theoretical calculations also various aircraft measurements of the backscattered radiances in the wavelength range from 600 to 1650 nm were carried out. These measurements are done with the above mentioned OVID, a new multichannel array spectrometer of the Universities of Hamburg and Berlin. First comparisons of these airborne CCD measurements with calculated spectra are shown.

  17. P50/P90 Analysis for Solar Energy Systems Using the System Advisor Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dobos, A. P.; Gilman, P.; Kasberg, M.

    2012-06-01

    To secure competitive financing for a solar energy generation project, the economic risk associated with interannual solar resource variability must be quantified. One way to quantify this risk is to calculate exceedance probabilities representing the amount of energy expected to be produced by a plant. Many years of solar radiation and metereological data are required to determine these values, often called P50 or P90 values for the level of certainty they represent. This paper describes the two methods implemented in the National Renewable Energy Laboratory's System Advisor Model (SAM) to calculate P50 and P90 exceedance probabilities for solar energy projects. The methodology and supporting data sets are applicable to photovoltaic, solar water heating, and concentrating solar power (CSP) systems.

  18. Solar Panel Mathematical Modeling Using Simulink

    Directory of Open Access Journals (Sweden)

    Chandani Sharma

    2014-05-01

    Full Text Available For decades, electricity is a key driver of socio-economy development. Nowadays, in the context of competition there is a direct relationship between electricity generation and sustainable development of the country. This paper presents distinct use of a Photovoltaic array offering great potential as source of electricity. The simulation uses One-diode equivalent circuit in order to investigate I-V and P-V characteristics. The GUI model is designed with Simulink block libraries. The goals of proposed model are to perform a systematic analysis, modeling and evaluation of the key subsystems for obtaining Maximum Power Point of a solar cell. Effect of increasing number of cells is described at Standard Test Conditions by mathematical modeling of equations. It is desirable to achieve maximum power output at a minimum cost under various operating conditions. Index Terms—

  19. Elementary Students' Mental Models of the Solar System

    Science.gov (United States)

    Calderon-Canales, Elena; Flores-Camacho, Fernando; Gallegos-Cazares, Leticia

    2013-01-01

    This research project aimed to identify and analyze Mexican primary school students' ideas about the components of the solar system. In particular, this study focused on conceptions of the solar system and representations of the dynamics of the solar system based on the functional and structural models that students make in school. Using a…

  20. Model validation studies of solar systems, Phase III. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, L.J.; Winn, C.B.

    1978-12-01

    Results obtained from a validation study of the TRNSYS, SIMSHAC, and SOLCOST solar system simulation and design are presented. Also included are comparisons between the FCHART and SOLCOST solar system design programs and some changes that were made to the SOLCOST program. Finally, results obtained from the analysis of several solar radiation models are presented. Separate abstracts were prepared for ten papers.

  1. Elementary Students' Mental Models of the Solar System

    Science.gov (United States)

    Calderon-Canales, Elena; Flores-Camacho, Fernando; Gallegos-Cazares, Leticia

    2013-01-01

    This research project aimed to identify and analyze Mexican primary school students' ideas about the components of the solar system. In particular, this study focused on conceptions of the solar system and representations of the dynamics of the solar system based on the functional and structural models that students make in school. Using a…

  2. Elementary Students' Mental Models of the Solar System

    Science.gov (United States)

    Calderon-Canales, Elena; Flores-Camacho, Fernando; Gallegos-Cazares, Leticia

    2013-01-01

    This research project aimed to identify and analyze Mexican primary school students' ideas about the components of the solar system. In particular, this study focused on conceptions of the solar system and representations of the dynamics of the solar system based on the functional and structural models that students make in school. Using a…

  3. Solar Cogeneration of Electricity and Hot Water at DoD Installations

    Science.gov (United States)

    2014-05-01

    However, as the tank heats up, the solar array is able to add less and less heat. This is because the thermal efficiency of any solar thermal collector ...PRFTA: Parks Reserve Force Training Area PV: photovoltaic PVT: photovoltaic and thermal SHW: solar hot water EXECUTIVE SUMMARY Cogenra Solar ...Inc. set out to demonstrate an innovative hybrid electric/ thermal solar cogeneration system at Port Hueneme (Naval Base Ventura County) and the

  4. Selective solar photodegradation of organopollutant mixtures in water

    Energy Technology Data Exchange (ETDEWEB)

    Robert, D.; Piscopo, A.; Weber, J.V. [Metz Univ., Saint-Avold (France). Lab. de Chimie et Applications

    2004-11-01

    Heterogeneous photocatalysis in a water solution is recognised as a method of totally eliminating most recalcitrant organic pollutants found in such solutions. Our current work has tried to show that the heterogeneous photocatalysis process can also be a selective elimination method in the case of the mixture: 4-hydroxybenzoic acid (4-HBz) and benzamide (Bz) at semi-pilot plant scale (190 dm{sup 3}) under conditions of solar irradiation. The photocatalysis experiments performed by us were done at the 'Plataforma Solar de Almeria' and were carried out in the compound parabolic collectors' CPC system. We investigated in particular the influence of TiO{sub 2} loading, the effect of 4-HBz concentration and the effect of the presence of chloride anions and pH on the selectivity of the reaction process. (Author)

  5. Efficiencies and Physical Principles of Various Solar Energy Conversion Processes Leading to the Photolysis of Water

    Energy Technology Data Exchange (ETDEWEB)

    Bergene, T.

    1995-12-31

    In the application of solar energy, hydrogen is likely to be used as an energy carrier and a storage medium. Production of molecular hydrogen and oxygen from water requires energy input, which may come from solar energy in various ways. This thesis begins with a literature survey of the different conversion processes and the efficiencies, which is an introduction to a series of enclosed papers. These papers are: (1) Trapping of Minority Charge Carriers at Irradiated Semiconductor/Electrolyte Heterojunctions, (2) Model Calculations on Flat-Plate Solar Heat Collector With Integrated Solar Cells, and (3) Efficiencies and Physical Principles of Photolysis of Water By Microalgae. In the papers, The qualitative features of the ``illumination-current``-characteristic curve are deduced. The hypothesis is that trapping originates in some specific cases because of confinement, which leads to charge injections into energy states above that corresponding to the band edge. The quantitative features of certain hybrid photovoltaic/thermal configuration are deduced. An analysis of the theoretical and realizable efficiencies of the photolysis of water by micro algae is given. 151 refs., 18 figs., 1 table

  6. Effects of an Arctic under-ice bloom on solar radiant heating of the water column

    Science.gov (United States)

    Taskjelle, Torbjørn; Granskog, Mats A.; Pavlov, Alexey K.; Hudson, Stephen R.; Hamre, Børge

    2017-01-01

    The deposition of solar energy in the upper Arctic Ocean depends, among other things, on the composition of the water column. During the N-ICE2015 expedition, a drift in the Arctic pack ice north of Svalbard, an under-ice phytoplankton bloom was encountered in May 2015. This bloom led to significant changes in the inherent optical properties (IOPs) of the upper ocean. Mean values of total water absorption in the upper 20 m of the water column were up to 4 times higher during the bloom than prior to it. The total water attenuation coefficient increased by a factor of up to around 7. Radiative transfer modeling, with measured IOPs as input, has been performed with a coupled atmosphere-ice-ocean model. Simulations are used to investigate the change in depth-dependent solar heating of the ocean after the onset of the bloom, for wavelengths in the region 350-700 nm. Effects of clouds, sea ice cover, solar zenith angle, as well as the average cosine for scattering of the ocean inclusions are evaluated. An increase in energy absorption in the upper 10 m of about 36% is found under 25 cm ice with 2 cm snow, for bloom conditions relative to prebloom conditions, which may have implications for ice melt and growth in spring. Thicker clouds and lower sun reduce the irradiance available, but lead to an increase in relative absorption.

  7. Design, Simulation, and Analysis of Domestic Solar Water Heating Systems in Phoenix, Arizona

    Science.gov (United States)

    De Fresart, Edouard Thomas

    Research was conducted to quantify the energy and cost savings of two different domestic solar water heating systems compared to an all-electric water heater for a four-person household in Phoenix, Arizona. The knowledge gained from this research will enable utilities to better align incentives and consumers to make more informed decisions prior to purchasing a solar water heater. Daily energy and temperature data were collected in a controlled, closed environment lab. Three mathematical models were designed in TRNSYS 17, a transient system simulation tool. The data from the lab were used to validate the TRNSYS models, and the TRNSYS results were used to project annual cost and energy savings for the solar water heaters. The projected energy savings for a four-person household in Phoenix, Arizona are 80% when using the SunEarthRTM system with an insulated and glazed flat-plate collector, and 49% when using the FAFCO RTM system with unglazed, non-insulated flat-plate collectors. Utilizing all available federal, state, and utility incentives, a consumer could expect to recoup his or her investment after the fifth year if purchasing a SunEarth RTM system, and after the eighth year if purchasing a FAFCO RTM system. Over the 20-year analysis period, a consumer could expect to save 2,519 with the SunEarthRTM system, and 971 with the FAFCORTM system.

  8. Accelerated shallow water modeling

    Science.gov (United States)

    Gandham, Rajesh; Medina, David; Warburton, Timothy

    2015-04-01

    ln this talk we will describe our ongoing developments in accelerated numerical methods for modeling tsunamis, and oceanic fluid flows using two dimensional shallow water model and/or three dimensional incompressible Navier Stokes model discretized with high order discontinuous Galerkin methods. High order discontinuous Galerkin methods can be computationally demanding, requiring extensive computational time to simulate real time events on traditional CPU architectures. However, recent advances in computing architectures and hardware aware algorithms make it possible to reduce simulation time and provide accurate predictions in a timely manner. Hence we tailor these algorithms to take advantage of single instruction multiple data (SIMD) architecture that is seen in modern many core compute devices such as GPUs. We will discuss our unified and extensive many-core programming library OCCA that alleviates the need to completely re-design the solvers to keep up with constantly evolving parallel programming models and hardware architectures. We will present performance results for the flow simulations demonstrating performance leveraging multiple different multi-threading APIs on GPU and CPU targets.

  9. Verification of high-speed solar wind stream forecasts using operational solar wind models

    OpenAIRE

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.; Nikolic, Ljubomir; Vennerstrom, Susanne; Schoengassner, Florian; Hofmeister, Stefan J.

    2016-01-01

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the ACE spacecraft for ...

  10. Modeling and analysis of solar distributed generation

    Science.gov (United States)

    Ortiz Rivera, Eduardo Ivan

    Recent changes in the global economy are creating a big impact in our daily life. The price of oil is increasing and the number of reserves are less every day. Also, dramatic demographic changes are impacting the viability of the electric infrastructure and ultimately the economic future of the industry. These are some of the reasons that many countries are looking for alternative energy to produce electric energy. The most common form of green energy in our daily life is solar energy. To convert solar energy into electrical energy is required solar panels, dc-dc converters, power control, sensors, and inverters. In this work, a photovoltaic module, PVM, model using the electrical characteristics provided by the manufacturer data sheet is presented for power system applications. Experimental results from testing are showed, verifying the proposed PVM model. Also in this work, three maximum power point tracker, MPPT, algorithms would be presented to obtain the maximum power from a PVM. The first MPPT algorithm is a method based on the Rolle's and Lagrange's Theorems and can provide at least an approximate answer to a family of transcendental functions that cannot be solved using differential calculus. The second MPPT algorithm is based on the approximation of the proposed PVM model using fractional polynomials where the shape, boundary conditions and performance of the proposed PVM model are satisfied. The third MPPT algorithm is based in the determination of the optimal duty cycle for a dc-dc converter and the previous knowledge of the load or load matching conditions. Also, four algorithms to calculate the effective irradiance level and temperature over a photovoltaic module are presented in this work. The main reasons to develop these algorithms are for monitoring climate conditions, the elimination of temperature and solar irradiance sensors, reductions in cost for a photovoltaic inverter system, and development of new algorithms to be integrated with maximum

  11. Solar water disinfection by singlet oxygen photogenerated with polymer-supported Ru(II) sensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Hernandez, M. Emilia; Manjon, Francisco; Garcia-Fresnadillo, David; Orellana, Guillermo [Laboratory of Applied Photochemistry, Department of Organic Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, 28040 Madrid (Spain)

    2006-10-15

    Using Escherichia coli and Enterococcus faecalis as model microorganisms, water disinfection has been demonstrated with singlet molecular oxygen (a reactive oxygen species) photogenerated by polymer-supported Ru(II) sensitizers and solar light. Both laboratory and sunlight tests were performed. The Ru(II) polypyridyl complex and its insoluble support have been optimized to provide maximum efficiency of singlet oxygen production and contact with the microorganism. (author)

  12. Thermal analysis and performance optimization of a solar hot water plant with economic evaluation

    KAUST Repository

    Kim, Youngdeuk

    2012-05-01

    The main objective of this study is to optimize the long-term performance of an existing active-indirect solar hot water plant (SHWP), which supplies hot water at 65 °C for use in a flight kitchen, using a micro genetic algorithm in conjunction with a relatively detailed model of each component in the plant and solar radiation model based on the measured data. The performance of SHWP at Changi International Airport Services (CIASs), Singapore, is studied for better payback period using the monthly average hourly diffuse and beam radiations and ambient temperature data. The data input for solar radiation model is obtained from the Singapore Meteorological Service (SMS), and these data have been compared with long-term average data of NASA (surface meteorology and solar energy or SSE). The comparison shows a good agreement between the predicted and measured hourly-averaged, horizontal global radiation. The SHWP at CIAS, which comprises 1200m 2 of evacuated-tube collectors, 50m 3 water storage tanks and a gas-fired auxiliary boiler, is first analyzed using a baseline configuration, i.e., (i) the local solar insolation input, (ii) a coolant flow rate through the headers of collector based on ASHRAE standards, (iii) a thermal load demand pattern amounting to 100m 3/day, and (iv) the augmentation of water temperature by auxiliary when the supply temperature from solar tank drops below the set point. A comparison between the baseline configuration and the measured performance of CIAS plant gives reasonably good validation of the simulation code. Optimization is further carried out for the following parameters, namely; (i) total collector area of the plant, (ii) storage volume, and (iii) three daily thermal demands. These studies are performed for both the CIAS plant and a slightly modified plant where the hot water supply to the load is adjusted constant at times when the water temperature from tank may exceed the set temperature. It is found that the latter

  13. WATER DIVERSION MODEL

    Energy Technology Data Exchange (ETDEWEB)

    J.B. Case

    1999-12-21

    The distribution of seepage in the proposed repository will be highly variable due in part to variations in the spatial distribution of percolations. The performance of the drip shield and the backfill system may divert the water flux around the waste packages to the invert. Diversion will occur along the drift surface, within the backfill, at the drip shield, and at the Waste Package (WP) surface, even after the drip shield and WP have been breached by corrosion. The purpose and objective of this Analysis and Modeling Report (AMR) are to develop a conceptual model and constitutive properties for bounding the volume and rate of seepage water that flows around the drip shield (CRWMS M&O 1999c). This analysis model is to be compatible with the selected repository conceptual design (Wilkins and Heath, 1999) and will be used to evaluate the performance of the Engineered Barrier System (EBS), and to provide input to the EBS Water Distribution and Removal Model. This model supports the Engineered Barrier System (EBS) postclosure performance assessment for the Site Recommendation (SR). This document characterizes the hydrological constitutive properties of the backfill and invert materials (Section 6.2) and a third material that represents a mixture of the two. These include the Overton Sand which is selected as a backfill (Section 5.2), crushed tuff which is selected as the invert (Section 5.1), and a combined material (Sections 5.9 and 5.10) which has retention and hydraulic conductivity properties intermediate to the selected materials for the backfill and the invert. The properties include the grain size distribution, the dry bulk density and porosity, the moisture retention, the intrinsic permeability, the relative permeability, and the material thermal properties. The van Genuchten relationships with curve fit parameters are used to define the basic retention relationship of moisture potential to volumetric moisture content, and the basic relationship of unsaturated

  14. Observations of Warm Water in Young Solar-System Analogs

    DEFF Research Database (Denmark)

    Persson, Magnus Vilhelm

    of water vapor in Earth’s atmosphere. Many of the lines that are observable from the ground are masing in star forming regions, making it hard to deduce abundances. The few lines that are observable, and shown not be masing are isotopologues, like HDO and D2O, making the estimates of the main isotopologue...... dioxide). The amount of warm water is deduced and its origin is observationally constrained. With both isotopologues observed, the HDO/H2O ratio is deduced. This ratio is then compared to other sources, e.g., comets and the Earth’s ocean, to gain understanding of the origin of the water in our own solar...

  15. Transtion metal oxides for solar water splitting devices

    Science.gov (United States)

    Smith, Adam M.

    Although the terrestrial flux of solar energy is enough to support human endeavors, storage of solar energy remains a significant challenge to large-scale implementation of solar energy production. One route to energy storage involves the capture and conversion of sunlight to chemical species such as molecular hydrogen and oxygen via water splitting devices. The oxygen evolution half-reaction particularly suffers from large kinetic overpotentials. Additionally, a photoactive material that exhibits stability in oxidizing conditions present during oxygen evolution represents a unique challenge for devices. These concerns can be potentially addressed with a metal oxide photoanode coupled with efficient water oxidation electrocatalysts. Despite decades of research, structure-composition to property relationships are still needed for the design of metal oxide oxygen evolution materials. This dissertation investigates transition metal oxide materials for the oxygen evolution portion of water splitting devices. Chapter I introduces key challenges for solar driven water splitting. Chapter II elucidates the growth mechanism of tungsten oxide (WOX) nanowires (NWs), a proposed photoanode material for water splitting. Key findings include (1) a planar defect-driven pseudo-one-dimensional growth mechanism and (2) morphological control through the supersaturation of vapor precursors. Result 1 is significant as it illustrates that common vapor-phase syntheses of WOX NWs depend on the formation of planar defects through NWs, which necessitates reconsideration of WOX as a photoanode. Chapter III presents work towards (1) single crystal WOX synthesis and characterization and (2) WOX NW device fabrication. Chapter IV makes use of the key result that WOX NWs are defect rich and therefore conductive in order to utilize them as a catalyst scaffold for oxygen evolution in acidic media. Work towards utilizing NW scaffolds include key results such as stability under anodic potentials and

  16. Research on the New Water Supply Model of Using Wind and Solar Complementation in Pastoral Areas%牧区风能太阳能供水新型模式研究

    Institute of Scientific and Technical Information of China (English)

    王世锋; 李亮; 曹亮

    2015-01-01

    我国北方牧区常规能源较为短缺,电网覆盖有限,很多地方还没有通电,但可再生能源的储量却非常丰富,在我国广大偏远北方牧区有丰富的风能和太阳能资源,风能太阳能供水已经成为解决牧区及偏远地区饮水安全问题的主力军。但由于风能太阳能能存在一定的不稳定性,靠单一能源供水保证率不高,不能很好满足牧区供水的需求。提出高保证率北方牧区风能太阳能互补供水新型高保证率的供水模式。%In the pastoral area of North China's conventional energy is shortage ,network coverage is limited ,and many places are still without electricity ,but renewable energy reserves is very rich ,is rich in wind and solar energy resources in China's vast remote pas‐toral areas in North China ,wind energy and solar energy water supply has become the main force to solve the drinking water security issues and pasturing areas and remote areas .But because the wind energy and solar energy can may be somewhat instable ,relying on a single energy guarantee rate of water supply is not high ,not very good for meeting the water demand in pastoral areas .This paper puts foward the high northern pastoral wind solar complementary water supply of new high assurance rate of water supply mode .

  17. Analysis of a solar water thermosyphon system; Analise do aquecimento solar de agua por sistema a termosifao

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, Abner Barzola

    1992-07-01

    A design methodology and to perform the simulation of flat plate solar collectors coupled with a water storage tank and operating by natural convection circulation is presented. For a given site the incident solar radiation on a tilted and previously oriented surface is determined from solar astronomy and the dally average of the monthly data of the horizontal total solar radiation. Huancayo situated in Peru (at 12.05 deg S, long. 76.18 deg W, altitude 3,312 m), is chosen as the site to be installed the solar water system, as a mean to improve the peasant's standard of life. An optimum tilt angle for a north oriented collector surface is obtained in order to have a maximum solar capture during the water. The theoretical methodology use here is based upon the ONG's paper (1976), and in attrition is considered the hot water drainage due to the dally consumption. For the sake of comparison, the calculated flowrate values are confronted with the experimental data obtained by FERNANDEZ, for a same site location (Rio de Janeiro) and are used identical dimensions for the water thermosyphon heater. Finally, the economic feasibility of the solar water system is demonstrated when it is compared with the usual immersion electric resistance boiler. For the Peruvian conditions the more adequate solar water system for a rural or domestic usage is a 1.4 m{sup 2} area solar collector (6 parallel, 15,875 mm copper tubes), 100 l capacity for the water storage tank, 33.5 mm for the connecting tubes, being of 300 mm. The height between the collector top and the bottom of the tank. (author)

  18. The Distribution of Solar Wind Speeds During Solar Minimum: Calibration for Numerical Solar Wind Modeling Constraints on the Source of the Slow Solar Wind (Postprint)

    Science.gov (United States)

    2012-03-05

    2003) and Schwadron et al. (2005) as constraints. The new relationship was tested by using it to drive the ENLIL 3‐D MHD solar wind model and obtain...it to drive the ENLIL 3‐D MHD solar wind model and obtain solar wind parameters at Earth (1.0 AU) and Ulysses (1.4 AU). The improvements in speed...propagated out into the heliosphere using the ENLIL solar wind model . ENLIL is a 3‐D Magne- tohydrodynamic ( MHD ) model of the heliosphere [Odstrcil, 2003

  19. Comparison of three systems of solar water heating by thermosiphon

    Science.gov (United States)

    Hernández, E.; Guzmán, R. E.

    2016-02-01

    The main purpose of this project was to elaborate a comparison between three water heating systems; using two plane water heating solar collector and another using a vacuum tube heater, all of them are on top of the cafeteria's roof on building of the “Universidad Pontificia Bolivariana” in Bucaramanga, Colombia. Through testing was determined each type of water heating systems' performance, where the Stainless Steel tube collector reached a maximum efficiency of 71.58%, the Copper Tubing Collector a maximum value of 76.31% and for the Vacuum Tube Heater Collector a maximum efficiency of 72.33%. The collector with copper coil was the system more efficient. So, taking into account the Performance and Temperature Curves, along with the weather conditions at the time of the testing we determined that the most efficient Solar Heating System is the one using a Vacuum Tube Heater Collector. Reaching a maximum efficiency of 72.33% and a maximum temperature of 62.6°C.

  20. Photoanodic Hybrid Semiconductor–Molecular Heterojunction for Solar Water Oxidation

    KAUST Repository

    Joya, Khurram Saleem

    2015-06-29

    Inorganic photo-responsive semiconducting materials have been employed in photoelectrochemical(PEC) water oxidation devicesin pursuit of solar to fuel conversion.[1]The reaction kinetics in semiconductors is limited by poor contact at the interfaces, and charge transfer is impeded by surface defects and the grain boundaries.[2]It has shown that successful surface functionalization of the photo-responsive semiconducting materials with co-catalysts can maximize the charge separation, hole delivery and its effective consumption, and enhances the efficiency and performane of the PEC based water oxidation assembly.[3]We present here unique modification of photoanodic hematite (α-Fe2O3) and bismuth vanadate (BiVO4) with molecular co-catalysts for enhanced photoelectrochemical water oxidation (Figure 1). These hybrid inorganic–organometallic heterojunctions manifest impressive cathodic shifts in the onset potentials, and the photocurrent densities have been enhanced by > 90% at all potentials relative to uncatalyzed α-Fe2O3 or BiVO4, and other catalyst-semiconductor based heterojunctions.This is a novel development in the solar to fuel conversion field, and is crucially important for designing a tandem device where light interfere very little with the catalyst layer on top of semiconducting light absorber.

  1. Water disinfection with solar radiation; Desinfeccion del agua con radiacion solar

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Alejandra; Cortes, Juana E; Rodriguez, Miriam; Mundo, Alfredo; Vazquez, Sandra [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico); Estrada, Claudio A [Centro de Investigacion en Energia, Temixco, Morelos (Mexico)

    2000-07-01

    Water disinfection by exposure to solar radiation is a low cost and easy application option to rural communities. The treatment of water can be done using plastic bags or plastic bottles of two litters setting on a reflective material. The efficient of the plastic bottles is lower than the one plastic bags, but the plastic bottles have a much better control of the treated water avoiding its recontamination. In order to increase the efficiency of disinfection using plastic bottles, two solar concentrators, using flat mirrors, were designed and built. Effluent water from a treatment plant of residual waters was used for the testing. Several comparison were carried out taking into account the position of the concentrators, the transparency of the bottles and the bags. The results show that using the concentrator that adjust its position to the sun every hour, a 100% disinfection is obtained in 4 hours of direct exposure to the sun rays in a sunny day. The period of time can be reduced up to 2 hours, if instead using transparent bottles, the bottles are black painted at their bottom half. With these results, the basis to design a cheap concentrator of easy construction to be used in rural communities have been settle. [Spanish] La desinfeccion del agua por exposicion a la luz solar fotodesinfeccion es una opcion de bajo costo y facil aplicacion para las comunidades rurales. El tratamiento puede llevarse a cabo utilizando bolsas o botellas de plastico transparente de dos litros de capacidad colocadas sobre un material reflejante. Las botellas son menos eficientes que las bolsas, pero permiten un mejor control del agua tratada evitando su recontaminacion. Para aumentar la eficiencia de la desinfeccion utilizando las botellas, se disenaron y construyeron dos concentradores solares de espejos planos que permitieron disminuir el tiempo de exposicion requerido cuando se utilizan estas. Para las pruebas de desinfeccion se utilizo agua del efluente de una planta de tratamiento

  2. An update of Leighton's solar dynamo model

    Science.gov (United States)

    Cameron, R. H.; Schüssler, M.

    2017-02-01

    In 1969, Leighton developed a quasi-1D mathematical model of the solar dynamo, building upon the phenomenological scenario of Babcock published in 1961. Here we present a modification and extension of Leighton's model. Using the axisymmetric component (longitudinal average) of the magnetic field, we consider the radial field component at the solar surface and the radially integrated toroidal magnetic flux in the convection zone, both as functions of latitude. No assumptions are made with regard to the radial location of the toroidal flux. The model includes the effects of (i) turbulent diffusion at the surface and in the convection zone; (ii) poleward meridional flow at the surface and an equatorward return flow affecting the toroidal flux; (iii) latitudinal differential rotation and the near-surface layer of radial rotational shear; (iv) downward convective pumping of magnetic flux in the shear layer; and (v) flux emergence in the form of tilted bipolar magnetic regions treated as a source term for the radial surface field. While the parameters relevant for the transport of the surface field are taken from observations, the model condenses the unknown properties of magnetic field and flow in the convection zone into a few free parameters (turbulent diffusivity, effective return flow, amplitude of the source term, and a parameter describing the effective radial shear). Comparison with the results of 2D flux transport dynamo codes shows that the model captures the essential features of these simulations. We make use of the computational efficiency of the model to carry out an extended parameter study. We cover an extended domain of the 4D parameter space and identify the parameter ranges that provide solar-like solutions. Dipole parity is always preferred and solutions with periods around 22 yr and a correct phase difference between flux emergence in low latitudes and the strength of the polar fields are found for a return flow speed around 2 m s-1, turbulent

  3. Study of thermal effects and optical properties of an innovative absorber in integrated collector storage solar water heater

    Science.gov (United States)

    Taheri, Yaser; Alimardani, Kazem; Ziapour, Behrooz M.

    2015-10-01

    Solar passive water heaters are potential candidates for enhanced heat transfer. Solar water heaters with an integrated water tank and with the low temperature energy resource are used as the simplest and cheapest recipient devices of the solar energy for heating and supplying hot water in the buildings. The solar thermal performances of one primitive absorber were determined by using both the experimental and the simulation model of it. All materials applied for absorber such as the cover glass, the black colored sands and the V shaped galvanized plate were submerged into the water. The water storage tank was manufactured from galvanized sheet of 0.0015 m in thickness and the effective area of the collector was 0.67 m2. The absorber was installed on a compact solar water heater. The constructed flat-plate collectors were tested outdoors. However the simulation results showed that the absorbers operated near to the gray materials and all experimental results showed that the thermal efficiencies of the collector are over than 70 %.

  4. Preliminary design package for solar heating and hot water system

    Energy Technology Data Exchange (ETDEWEB)

    Levine, P.; Meyer, R.; White, James S.

    1977-01-01

    A collection of documents submitted by the Fern Engineering Company for the preliminary design review on the development of two prototype solar heating and hot water systems is presented. The information includes system certification, system functional description, system configuration, system specification, system performance and other documents pertaining to the progress and the design of the system. This system, which is intended for use in the normal single-family residence, consists of the following subsystems: collector, storage, control, transport, and Government-furnished Site Data Acquisition. One of the two prototype units will be installed in Lansing, Michigan, and the other in Tunkhannock, Pennsylvania.

  5. Discovery of water ice nearly everywhere in the solar system

    Energy Technology Data Exchange (ETDEWEB)

    Zuppero, A.

    1995-10-01

    During the last decade we have discovered sources of accessible water in some form nearly everywhere in the solar system. Water ice has been found on the planet Mercury; probably on the Earth`s Moon; on Mars; on near Earth objects; on comets whose orbits frequently come close to that of Earth`s orbit; probably on Ceres, the largest inner asteroid; and on comets previously and incorrectly considered to be out of practical reach. The comets also provide massive quantities of hydrocarbons, similar to oil shale. The masses of either water or hydrocarbons are measured in units of cubic kilometers. The water is key to space transportation because it can be used as a rocket propellant directly, and because thermal process alone can be used to convert it and hydrocarbons into hydrogen, the highest performing rocket propellant. This presentation outlines what is currently known about the locations of the water ice, and sketches the requirements and environments of missions to prospect for and assay the water sources.

  6. Exegetic evaluation of solar heating water thermosyphonic; Evaluacion exergetica de sistemas de calentamiento de agua solares termosifonicos

    Energy Technology Data Exchange (ETDEWEB)

    Barral, J. R.; Andreani, R. J. L.; Lucchini, J. M.; Fasulo, A. J.

    2004-07-01

    A tool has been developed in order to analyse by means of the exegetic method the behaviour of a solar water heating thermosyphonic system composed by a flat plate collector and a tank, aided by a auxiliary conventional heater. A computational model run annual simulations, using data obtained from normalized test for commercial flat plate collectors. Taking into account the hot water demand and the climatic conditions, it is possible to determine the critical points of exergy destruction from de project design and the assembly of the system components, integrating the values for one typical year. Therefore, different combinations collector-tank can be tested in order to select the necessary auxiliary heater, looking for an economic optimized system. (Author)

  7. Combined Active and Passive Solar Space Heating and Solar Hot Water Systems for an Elementary School in Boise, Idaho.

    Science.gov (United States)

    Smull, Neil A.; Armstrong, Gerald L.

    1979-01-01

    Amity Elementary School in Boise, Idaho, features a solar space heating and domestic hot water system along with an earth covering to accommodate the passive aspects of energy conservation. (Author/MLF)

  8. 新型建筑制冷采暖热水一体化系统及模型分析%New Integrated Solar System of Refrigeration and Heating with Hot Water for Building and Model Analysis

    Institute of Scientific and Technical Information of China (English)

    山石泉; 李媛

    2016-01-01

    立足于节能减排的大背景,提出一种新型的制冷采暖热水一体化系统。基于 DeST 软件平台模拟的气象数据,通过建立系统各个模块的模型对系统的节能性、经济性以及 CO2减排性进行了分析,结果表明一体化系统有显著的节能及环保性。如果能大规模使用,会有可观的经济与社会效益。%Based on the background of energy saving and emission reduction, a new type of integrat-ed solar system for refrigeration and heating with hot water is proposed. Based on the meteorological data from DeST software simulation platform, the energy saving, economy and CO2 emission reduction of the sys-tem is analyzed by establishing the system model of the various parts of the system. The results show that the integrated system has obvious energy saving property and environmental protection property. If it can be used on a large scale, there will be considerable economic and social benefits.

  9. Study on Water Model of Solar Energy and Vacuum Glass Grain Drying Equipment%太阳能真空玻璃谷物干燥装置水势模型研究

    Institute of Scientific and Technical Information of China (English)

    沈辉; 叶盛勇; 鞠海蒙; 孙亚; 孙健

    2014-01-01

    The paper introduces the process flow of solar energy and vacuum glass grain drying equipment. Research on the water flow model of inside grain. Calculate grain moisture content about each drying cycle. Researches show that grain moisture content falls below 14.036 8%after nine drying loops,and falling below 12.974 1%after twelve drying loops,and It is hard to continue to reducing the moisture. Calculated the dry-ing time is 2.57 hours.%在设计太阳能真空玻璃谷物干燥装置的基础上,对其干燥工艺流程进行分析,建立谷物内部水分的流动模型,对谷物干燥循环过程中谷物的含水率进行模拟计算,试验研究与分析表明,干燥9个循环时间后,谷物的含水率达到14.0368%,在12个循环之后,谷物含水率下降到12.9741%,之后很难继续降低含水率。干燥效率最佳,谷物在仓内干燥最佳时间为2.57 h。

  10. Modeling Scattering Polarization for Probing Solar Magnetism

    CERN Document Server

    Bueno, Javier Trujillo

    2011-01-01

    This paper considers the problem of modeling the light polarization that emerges from an astrophysical plasma composed of atoms whose excitation state is significantly influenced by the anisotropy of the incident radiation field. In particular, it highlights how radiative transfer simulations in three-dimensional models of the quiet solar atmosphere may help us to probe its thermal and magnetic structure, from the near equilibrium photosphere to the highly non-equilibrium upper chromosphere. The paper finishes with predictions concerning the amplitudes and magnetic sensitivities of the linear polarization signals produced by scattering processes in two transition region lines, which should encourage us to develop UV polarimeters for sounding rockets and space telescopes with the aim of opening up a new diagnostic window in astrophysics.

  11. Study on Thermal Performance Assessment of Solar Hot Water Systems in Malaysia

    Directory of Open Access Journals (Sweden)

    Sulaiman Shaharin Anwar

    2014-07-01

    Full Text Available Solar Hot Water Systems (SHWS are gaining popularity in Malaysia due to increasing cost of electricity and also awareness of environmental issues related to the use of fossil fuels. The introduction of solar hot water systems in Malaysia is an indication that it has potential market. However, there is a need for a proper methodology for rating the energy performance of these systems. The main objective of this study is to assess the thermal performance of several SHWS subject to four different locations in Malaysia using combined direct measurement and computer modelling using the TRNSYS simulation program. The results showed distinct differences in performance of the systems as a result of locations and manufacturers. The findings could be used further in developing an acceptable rating system for SHWS in Malaysia.

  12. Preliminary ECLSS waste water model

    Science.gov (United States)

    Carter, Donald L.; Holder, Donald W., Jr.; Alexander, Kevin; Shaw, R. G.; Hayase, John K.

    1991-01-01

    A preliminary waste water model for input to the Space Station Freedom (SSF) Environmental Control and Life Support System (ECLSS) Water Processor (WP) has been generated for design purposes. Data have been compiled from various ECLSS tests and flight sample analyses. A discussion of the characterization of the waste streams comprising the model is presented, along with a discussion of the waste water model and the rationale for the inclusion of contaminants in their respective concentrations. The major objective is to establish a methodology for the development of a waste water model and to present the current state of that model.

  13. Preliminary ECLSS waste water model

    Science.gov (United States)

    Carter, Donald L.; Holder, Donald W., Jr.; Alexander, Kevin; Shaw, R. G.; Hayase, John K.

    1991-01-01

    A preliminary waste water model for input to the Space Station Freedom (SSF) Environmental Control and Life Support System (ECLSS) Water Processor (WP) has been generated for design purposes. Data have been compiled from various ECLSS tests and flight sample analyses. A discussion of the characterization of the waste streams comprising the model is presented, along with a discussion of the waste water model and the rationale for the inclusion of contaminants in their respective concentrations. The major objective is to establish a methodology for the development of a waste water model and to present the current state of that model.

  14. Solar spectral irradiance variability in cycle 24: observations and models

    Directory of Open Access Journals (Sweden)

    Marchenko Sergey V.

    2016-01-01

    Full Text Available Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI, we characterize both short-term (solar rotation and long-term (solar cycle changes of the solar spectral irradiance (SSI between 265 and 500 nm during the ongoing cycle 24. We supplement the OMI data with concurrent observations from the Global Ozone Monitoring Experiment-2 (GOME-2 and Solar Radiation and Climate Experiment (SORCE instruments and find fair-to-excellent, depending on wavelength, agreement among the observations, and predictions of the Naval Research Laboratory Solar Spectral Irradiance (NRLSSI2 and Spectral And Total Irradiance REconstruction for the Satellite era (SATIRE-S models.

  15. Solar Radiation Model for Development and Control of Solar Energy Sources

    Directory of Open Access Journals (Sweden)

    Dominykas Vasarevičius

    2016-06-01

    Full Text Available The model of solar radiation, which takes into account direct, diffused and reflected components of solar energy, has been presented. Model is associated with geographical coordinates and local time of every day of the year. It is shown that using analytic equations for modelling the direct component, it is possible to adopt it for embedded systems with low computational power and use in solar tracking applications. Reflected and diffused components are especially useful in determining the performance of photovoltaic modules in certain location and surroundings. The statistical method for cloud layer simulation based on local meteorological data is offered. The presented method can’t be used for prediction of weather conditions but it provides patterns of solar radiation in time comparable to those measured with pyranometer. Cloud layer simulation together with total solar radiation model is a useful tool for development and analysis of maximum power point tracking controllers for PV modules.

  16. Solar Water Splitting: Photocatalyst Materials Discovery and Systems Development

    Energy Technology Data Exchange (ETDEWEB)

    McNulty, Thomas F.

    2008-05-02

    Hydrogen promises to be an attractive transportation fuel in the post-fossil fuel era. Relatively abundant and clean burning (water being the principal byproduct), hydrogen offers the potential to significantly reduce greenhouse gas emissions. However, there are significant technical barriers that require solutions before hydrogen can be implemented in large scale. These are: · Sources (e.g. hydrocarbon, water) · Transportation · Storage Each of the aforementioned barriers carries with it important considerations. First, would a hydrocarbon-based hydrogen source be of any benefit compared to conventional fossil fuels? Second, will a system based on centralized generation and distribution be viable? Finally, methods of on-board storage, whether they are liquefaction, adsorption, or intercalation, are far from optimized. The scope of this program is limited to hydrogen generation, specifically generation using solarinitiated water electrolysis. Though concept of making hydrogen using water and sunlight may sound somewhat far-fetched, in reality the concept is very real. Since the discovery of solar-generated hydrogen, termed photoelectrochemical hydrogen, nearly 30 years ago by Fujishima and Honda, significant advances in both fundamental understanding and technological capability have been made. Using solar radiation to generate hydrogen in a fashion akin to using solar to generate electricity offers many advantages. First, hydrogen can be generated at the point of use, reducing the importance of transportation. Second, using water as the hydrogen source eliminates greenhouse gas evolution and the consequences that come with it. Finally, because the process uses very little electricity (pumps and compressors predominantly), the quantity of chemical fuel produced far exceeds the amount of electricity consumed. Consequently, there is some level of truth to the notion that photoelectrochemically-derived hydrogen offers the potential to nearly eliminate greenhouse

  17. Thermal performance of solar water heater system in Yemen

    Energy Technology Data Exchange (ETDEWEB)

    Abdulla Aziz, G.M.; Mukbel, M.A. (Aden Univ., (Yemen, Republic of). Faculty of Engineering)

    1994-01-01

    A thermosyphonic solar water heating system was designed and fabricated from available materials. The risers of galvanized iron are fixed to an aluminium absorber plate by using an Omiga-in and Omiga-out technique. The collector absorber has an aperture area of 127 cm x 91 cm and is connected to a storage tank with 124 l capacity. The system was then tested under the climatical conditions of Aden city. The performance of characteristics of the system, under 'nondrawn off' and ''drawoff'' hot water conditions, are experimentally determined and then compared with the theoretical results. The results are quite satisfactory. The maximum efficiency reached 79%, with mean storage tank temperature of 60[sup o]C. (author)

  18. Promising freeze protection alternatives in solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, D.E.

    1997-12-31

    Since the gains associated with solar thermal energy technologies are comparatively small in relation to the required capital investment, it is vital to maximize conversion efficiency. While providing the necessary function of freeze protection, the heat exchanger commonly included in solar domestic water heating systems represents a system inefficiency. This thesis explores two alternate methods of providing freeze protection without resorting to a heat exchanger. Commonly, collectors are made of rigid copper tubes separated by copper or aluminum fins. Cracking damage can occur when water is allowed to freeze and expand inside the non compliant tubes. The possibility of making collectors out of an elastic material was investigated and shown to be effective. Since unlike copper, elastomers typically have low thermal conductivities, the standard collector performance prediction equations do not apply. Modified thermal performance prediction equations were developed which can be used for both low and high thermal conductivity materials to provide accurate predictions within a limited range of plate geometries. An elastomeric collector plate was then designed and shown to have comparable performance to a copper plate collector whose aperture area is approximately 33% smaller. Another options for providing freeze protection to an SDHW system is to turn it off during the winter. Choosing a three-season operating period means two things. First, the system will have different optimums such as slope and collector area. Second, the wintertime solar energy incident on the collector is unavailable for meeting a heating load. However, the system`s heat exchanger becomes unnecessary and removing it increases the amount of energy that arrives at the storage tank during those periods in which the system is operating.

  19. Promising freeze protection alternatives in solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, David E. [Univ. of Wisconsin, Madison, WI (United States)

    1997-01-01

    Since the gains associated with solar thermal energy technologies are comparatively small in relation to the required capital investment, it is vital to maximize conversion efficiency. While providing the necessary function of freeze protection, the heat exchanger commonly included in solar domestic water heating systems represents a system inefficiency. This thesis explores two alternate methods of providing freeze protection without resorting to a heat exchanger. Commonly, collectors are made of rigid copper tubes separated by copper or aluminum fins. Cracking damage can occur when water is allowed to freeze and expand inside the non compliant tubes. The possibility of making collectors out of an elastic material was investigated and shown to be effective. Since unlike copper, elastomers typically have low thermal conductivities, the standard collector performance prediction equations do not apply. Modified thermal performance prediction equations were developed which can be used for both low and high thermal conductivity materials to provide accurate predictions within a limited range of plate geometries. An elastomeric collector plate was then designed and shown to have comparable performance to a copper plate collector whose aperture area is approximately 33% smaller. Another options for providing freeze protection to an SDHW system is to turn it off during the winter. Choosing a three-season operating period means two things. First, the system will have different optimums such as slope and collector area. Second, the wintertime solar energy incident on the collector is unavailable for meeting a heating load. However, the system`s heat exchanger becomes unnecessary and removing it increases the amount of energy that arrives at the storage tank during those periods in which the system is operating.

  20. Multithread Hydrodynamic Modeling of a Solar Flare

    Science.gov (United States)

    Warren, Harry P.

    2006-01-01

    Past hydrodynamic simulations have been able to reproduce the high temperatures and densities characteristic of solar flares. These simulations, however, have not been able to account for the slow decay of the observed flare emission or the absence of blueshifts in high spectral resolution line profiles. Recent work has suggested that modeling a flare as a sequence of independently heated threads instead of as a single loop may resolve the discrepancies between the simulations and observations. In this paper, we present a method for computing multithread, time-dependent hydrodynamic simulations of solar flares and apply it to observations of the Masuda flare of 1992 January 13. We show that it is possible to reproduce the temporal evolution of high temperature thermal flare plasma observed with the instruments on the GOES and Yohkoh satellites. The results from these simulations suggest that the heating timescale for a individual thread is on the order of 200 s. Significantly shorter heating timescales (20 s) lead to very high temperatures and are inconsistent with the emission observed by Yohkoh.

  1. SELCO: A model for solar rural electrification in India

    Science.gov (United States)

    Hande, H. Harish

    1999-11-01

    The following thesis presents the concept of a Rural Energy Service Company in India, known as SELCO. The model is being set up as a sustainable proposition for the implementation of solar photovoltaics as a viable alternative to provide reliable home lighting in the rural areas of India. The SELCO approach has already achieved noteworthy social and commercial results. Institutional, policy and operational problems have long plagued the rural electrification programs in India, resulting in thousands of villages without access to electricity. SELCO is a solar energy service company operating in Southern India since 1995, focusing on the enormous untapped market for home lighting where thousands of households have no access to electricity and severe power shortages face those already connected to the electric grid. The Company has installed nearly 2,000 solar home lighting systems. From a modest two employees company in 1995, it has grown to 35 in 1997 and from one office to eight. The hypothesis to be tested in this study is that in rural India, in a market not subsidized by the government, a solar service company with available loans from local banks and cooperatives and with sales, installation, and maintenance personnel in the villages can be successful in introducing photovoltaic systems to provide basic amenities such as lighting and water pumping for the improvement of the quality of life, public health, and the environment. The initial success of SELCO lends considerable evidence to the acceptance of the hypothesis. To accomplish its mission, SELCO works with commercial, retail, and rural development banks with large rural branch networks to stimulate loans to SELCO's customers based on a standard set of attractive financing terms. SELCO through its successful model has convinced the policy makers that a way to increase rural families' access to consumer financing for solar home lighting systems is through the existing financial network available in the

  2. A Physics-based Analytical Model for Perovskite Solar Cells

    OpenAIRE

    Sun, Xingshu; Asadpour, Reza; Nie, Wanyi; Mohite, Aditya D.; Alam, Muhammad A.

    2015-01-01

    Perovskites are promising next-generation absorber materials for low-cost and high-efficiency solar cells. Although perovskite cells are configured similar to the classical solar cells, their operation is unique and requires development of a new physical model for characterization, optimization of the cells, and prediction of the panel performance. In this paper, we develop such a physics-based analytical model to describe the operation of different types of perovskite solar cells, explicitly...

  3. Conserving water in and applying solar power to haemodialysis: 'green dialysis' through wiser resource utilization.

    Science.gov (United States)

    Agar, John W M

    2010-06-01

    Natural resources are under worldwide pressure, water and sustainable energy being the paramount issues. Haemodialysis, a water-voracious and energy-hungry healthcare procedure, thoughtlessly wastes water and leaves a heavy carbon footprint. In our service, 100 000 L/week of previously discarded reverse osmosis reject water--water which satisfies all World Health Organisation criteria for potable (drinking) water--no longer drains to waste but is captured for reuse. Reject water from the hospital-based dialysis unit provides autoclave steam for instrument sterilization, ward toilet flushing, janitor stations and garden maintenance. Satellite centre reject water is tanker-trucked to community sporting fields, schools and aged-care gardens. Home-based nocturnal dialysis patient reuse reject water for home domestic utilities, gardens and animal watering. Although these and other potential water reuse practices should be mandated through legislation for all dialysis services, this is yet to occur. In addition, we now are piloting the use of solar power for the reverse osmosis plant and the dialysis machines in our home dialysis training service. If previously attempted, these have yet to be reported. After measuring the power requirements of both dialytic processes and modelling the projected costs, a programme has begun to solar power all dialysis-related equipment in a three-station home haemodialysis training unit. Income-generation with the national electricity grid via a grid-share and reimbursement arrangement predicts a revenue stream back to the dialysis service. Dialysis services must no longer ignore the non-medical aspects of their programmes but plan, trial, implement and embrace 'green dialysis' resource management practices.

  4. Solar radiation disinfection of drinking water at temperate latitudes: inactivation rates for an optimised reactor configuration.

    Science.gov (United States)

    Davies, C M; Roser, D J; Feitz, A J; Ashbolt, N J

    2009-02-01

    Solar radiation-driven inactivation of bacteria, virus and protozoan pathogen models was quantified in simulated drinking water at a temperate latitude (34 degrees S). The water was seeded with Enterococcus faecalis, Clostridium sporogenes spores, and P22 bacteriophage, each at ca 1x10(5) mL(-1), and exposed to natural sunlight in 30-L reaction vessels. Water temperature ranged from 17 to 39 degrees C during the experiments lasting up to 6h. Dark controls showed little inactivation and so it was concluded that the inactivation observed was primarily driven by non-thermal processes. The optimised reactor design achieved S90 values (cumulative exposure required for 90% reduction) for the test microorganisms in the range 0.63-1.82 MJ m(-2) of Global Solar Exposure (GSX) without the need for TiO2 as a catalyst. High turbidity (840-920 NTU) only reduced the S(90) value by 0.05). However, inactivation was significantly reduced for E. faecalis and P22 when the transmittance of UV wavelengths was attenuated by water with high colour (140 PtCo units) or a suboptimally transparent reactor lid (prob.waters and microorganisms. Although temperatures required for SODIS type pasteurization were not produced, non-thermal inactivation alone appeared to offer a viable means for reliably disinfecting low colour source waters by greater than 4 orders of magnitude on sunny days at 34 degrees S latitude.

  5. Solar Coronal Jets: Observations, Theory, and Modeling

    CERN Document Server

    Raouafi, N E; Pariat, E; Young, P R; Sterling, A C; Savcheva, A; Shimojo, M; Moreno-Insertis, F; DeVore, C R; Archontis, V; Török, T; Mason, H; Curdt, W; Meyer, K; Dalmasse, K; Matsui, Y

    2016-01-01

    Coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of significant mass and energy input to the upper solar atmosphere and the solar wind. While the energy involved in a jet-like event is smaller than that of "nominal" solar flares and coronal mass ejections (CMEs), jets share many common properties with these phenomena, in particular, the explosive magnetically driven dynamics. Studies of jets could, therefore, provide critical insight for understanding the larger, more complex drivers of the solar activity. On the other side of the size-spectrum, the study of jets could also supply important clues on the physics of transients close or at the limit of the current spatial resolution such as spicules. Furthermore, jet phenomena may hint to basic process for heating the corona and accelerating the solar wind; consequently their study gives us the opportunity to attack a broad range of solar-heliospheric problems.

  6. Surface-effect corrections for the solar model

    CERN Document Server

    Magic, Zazralt

    2016-01-01

    Solar p-mode oscillations exhibit a systematic offset towards higher frequencies due to shortcomings in the 1D stellar structure models, especially, the lack of turbulent pressure in the superadiabatic layers just below the optical surface, arising from the convective velocity field. We study the influence of the turbulent expansion, chemical composition, and magnetic fields on the stratification in the upper layers of the solar models in comparison with solar observations. Furthermore, we test alternative averages for improved results on the oscillation frequencies. We appended temporally and spatially averaged stratifications to 1D models to compute adiabatic oscillation frequencies that we then tested against observations. We also developed depth-dependent corrections for the solar 1D model, for which we expanded the geometrical depth to match the pressure stratification of the solar model, and we reduced the density that is caused by the turbulent pressure. We obtain the same results with our models a...

  7. Water and Volatiles in the Outer Solar System

    Science.gov (United States)

    Grasset, O.; Castillo-Rogez, J.; Guillot, T.; Fletcher, L. N.; Tosi, F.

    2017-08-01

    Space exploration and ground-based observations have provided outstanding evidence of the diversity and the complexity of the outer solar system. This work presents our current understanding of the nature and distribution of water and water-rich materials from the water snow line to the Kuiper Belt. This synthesis is timely, since a thorough exploration of at least one object in each region of the outer solar system has now been achieved. Next steps, starting with the Juno mission now in orbit around Jupiter, will be more focused on understanding the processes at work than on describing the general characteristics of each giant planet systems. This review is organized in three parts. First, the nature and the distribution of water and volatiles in giant and intermediary planets are described from their inner core to their outer envelopes. A special focus is given to Jupiter and Saturn, which are much better understood than the two ice giants (Uranus and Neptune) thanks to the Galileo and Cassini missions. Second, the icy moons will be discussed. Space missions and ground-based observations have revealed the variety of icy surfaces in the outer system. While Europa, Enceladus, and maybe Titan present past or even active tectonic and volcanic activities, many other moons have been dead worlds for more than 3 billion years. Ice compositions found at these bodies are also complex and it is now commonly admitted that icy surfaces are never composed of pure ices. A detailed review of the distribution of non-ice materials on the surfaces and in the tenuous atmospheres of the moons is proposed, followed by a more focused discussion on the nature and the characteristics of the liquid layers trapped below the cold icy crusts that have been suggested in the icy Galilean moons, and in Enceladus, Dione, and Titan at Saturn. Finally, the recent observations collected by Dawn at Ceres and New Horizons at Pluto, as well as the state of knowledge of other transneptunian objects

  8. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.

    2016-01-01

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...... high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation...... between the coronal hole area observed in Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images and solar wind properties at the near-Earth environment, the WSA model establishes a link between properties of the open magnetic field lines extending from the photosphere to the corona...

  9. Solar system tests of brane world models

    CERN Document Server

    Boehmer, Christian G; Lobo, Francisco S N

    2008-01-01

    The classical tests of general relativity (perihelion precession, deflection of light, and the radar echo delay) are considered for the Dadhich, Maartens, Papadopoulos and Rezania (DMPR) solution of the spherically symmetric static vacuum field equations in brane world models. For this solution the metric in the vacuum exterior to a brane world star is similar to the Reissner-Nordstrom form of classical general relativity, with the role of the charge played by the tidal effects arising from projections of the fifth dimension. The existing observational solar system data on the perihelion shift of Mercury, on the light bending around the Sun (obtained using long-baseline radio interferometry), and ranging to Mars using the Viking lander, constrain the numerical values of the bulk tidal parameter and of the brane tension.

  10. Theoretical model of a photoelectrochemical solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, S.; Singh, S.L.; Khare, N.

    1986-03-01

    A Schottky barrier theoretical model for explaining the J-V characteristic of a photoelectrochemical solar cell (PESC) has been developed considering the effect of dark current, space-charge recombination, surface states, and detailed charge transfer kinetics at the interface. Both isoenergetic charge transfer and inelastic charge transfers (via surface states) at the interface have been considered and their relative importance are discussed. The theory has been applied to explain the (a) J-V characteristic for n-GaAs/SeS , SeS 2 junction and (b) Fermi-level pinning observed in GaAs PESC. The inelastic charge transfer via surfaces states has been shown to play an important role in deciding these characteristics.

  11. A UNIFIED MODEL FOR SOLAR FLARES

    Institute of Scientific and Technical Information of China (English)

    ChenPengfei; FangCheng; DingMingde; TangYuhua

    1999-01-01

    We performed 2.5 - dimensional numerical simulation for two cases, one with the the reconnection point at a high altitude, the other with the reconnection point at a low altitude, in the high-altitude case, the bright loop appears to rise for a long time, with its two footpoints separating and the field lines below the bright loop shrinking,which are all typical features of two - ribbon flares. In the low- altitude case, the bright loops cease rising only a short time after the impulsive phase of the reconnection and then become rather stable, which shows a large similarity to the compact flares. The results imply that the two types of solar flares, i. e., the two - ribbon flares and the compact ones, might be unified into the same magnetic reconnection model, where the height of the reconnection point leads to the bifurcation.

  12. Solar system tests of brane world models

    Energy Technology Data Exchange (ETDEWEB)

    Boehmer, Christian G [Department of Mathematics, University College London, Gower Street, London WC1E 6BT (United Kingdom); Harko, Tiberiu [Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong); Lobo, Francisco S N [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 2EG (United Kingdom)], E-mail: c.boehmer@ucl.ac.uk, E-mail: harko@hkucc.hku.hk, E-mail: francisco.lobo@port.ac.uk

    2008-02-21

    The classical tests of general relativity (perihelion precession, deflection of light and the radar echo delay) are considered for the Dadhich, Maartens, Papadopoulos and Rezania (DMPR) solution of the spherically symmetric static vacuum field equations in brane world models. For this solution the metric in the vacuum exterior to a brane world star is similar to the Reissner-Nordstroem form of classical general relativity, with the role of the charge played by the tidal effects arising from projections of the fifth dimension. The existing observational solar system data on the perihelion shift of Mercury, on the light bending around the Sun (obtained using long-baseline radio interferometry), and ranging to Mars using the Viking lander, constrain the numerical values of the bulk tidal parameter and of the brane tension.

  13. Operation of the computer model for microenvironment solar exposure

    Science.gov (United States)

    Gillis, J. R.; Bourassa, R. J.; Gruenbaum, P. E.

    1995-01-01

    A computer model for microenvironmental solar exposure was developed to predict solar exposure to satellite surfaces which may shadow or reflect on one another. This document describes the technical features of the model as well as instructions for the installation and use of the program.

  14. INTEGRATED MODEL OF A SOLAR CHIMNEY EQUIPPED WITH AXIAL TURBINES

    OpenAIRE

    2015-01-01

    An integrated model of solar chim??ney (solar collector; turbine; tower) is presented; validated against data of the Manzanares plant; extended to the case of a 1000m tower. The model includes off-design performance of collector/turbine.

  15. Mathematical and computational modeling simulation of solar drying Systems

    Science.gov (United States)

    Mathematical modeling of solar drying systems has the primary aim of predicting the required drying time for a given commodity, dryer type, and environment. Both fundamental (Fickian diffusion) and semi-empirical drying models have been applied to the solar drying of a variety of agricultural commo...

  16. FIRST NEW SOLAR MODELS WITH OPAS OPACITY TABLES

    Energy Technology Data Exchange (ETDEWEB)

    Le Pennec, M.; Turck-Chièze, S.; Salmon, S. [CEA/IRFU/Service d’Astrophysique, CE Saclay, F-91191 Gif sur Yvette (France); Blancard, C.; Cossé, P.; Faussurier, G.; Mondet, G. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2015-11-10

    Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However, the particular case of the Sun is still challenging. For about a decade now, the helioseismic sound-speed determination has continued to disagree with the standard solar model (SSM) prediction, questioning the reliability of this model. One of the sources of uncertainty could be in the treatment of the transport of radiation from the solar core to the surface. In this Letter, we use the new OPAS opacity tables, recently available for solar modeling, to address this issue. We discuss first the peculiarities of these tables, then we quantify their impact on the solar sound-speed and density profiles using the reduced OPAS tables taken on the grids of the OPAL ones. We use the two evolution codes, Modules for Experiments in Stellar Astrophysics and Code Liégeois d’Evolution Stellaire, that led to similar conclusions in the solar radiative zone. In comparison to commonly used OPAL opacity tables, the new solar models are computed for the most recent photospheric composition with OPAS tables and present improvements to the location of the base of the convective zone and to the description of the solar radiative zone in comparison to the helioseismic observations, even if the differences in the Rosseland mean opacity do not exceed 6%. We finally carry out a comparison to a solar model computed with the OP opacity tables.

  17. Design of absorption system water-ammonia by using solar radiation as thermal source

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti, Eduardo J. Cidade; Souza, Luiz Guilherme Meira [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Tecnlogia. Dept. de Engenharia Mecanica], E-mails: educanti@gmail.com, lguilherme@dem.ufrn.br

    2010-07-01

    An absorption refrigeration system with the single effect of par ammonia water with 1.758 kW (1 / 2 RT) cooling capacity was designed. The system was operating under conditions of 5 degree C evaporation and 45 degree C condensation temperature. The absorption system has a heat exchanger to improve performance. The heat source is the cylinder parabolic solar concentrator (CPC). The design of the concentrator was estimated based on experimental data of the pilot plant built in the Solar Energy Laboratory, Federal University of Rio Grande do Norte. The thermodynamic model with heat and mass transfer was made to the project areas of heat exchange (absorber) and consequent construction of the system. The rectifying column was modeling assuming that liquid is in equilibrium with the vapor state in all plate. The results should show the dimensions of the compact and allows a future assessment of the operational cost. (author)

  18. Modelling water temperature in TOXSWA

    NARCIS (Netherlands)

    Jacobs, C.M.J.; Deneer, J.W.; Adriaanse, P.I.

    2010-01-01

    A reasonably accurate estimate of the water temperature is necessary for a good description of the degradation of plant protection products in water which is used in the surface water model TOXSWA. Based on a consideration of basic physical processes that describe the influence of weather on the

  19. Experimental Investigation on a Thermal Model for a Basin Solar Still with an External Reflector

    Directory of Open Access Journals (Sweden)

    Masoud Afrand

    2016-12-01

    Full Text Available In this study, a thermal model for estimating the efficiency of a basin solar still with an external reflector was introduced using the energy balance equations of different parts of the solar still. Then, in order to verify the precision and accuracy of this model, a basin solar still with an external reflector was constructed and some experiments were performed. The hourly temperature values for different places of the still and amount of distilled water were calculated using the thermal model and compared with experimental measurements. Comparisons show that the thermal model of the still is in good agreement with the experimental results. Therefore, it can be concluded that the introduced thermal model can be used reliably to estimate the amount of distilled water and efficiency of the basin solar still with an external reflector. Results also revealed that the efficiency of the solar still is low in the early hours, while it was enhanced 44% in the afternoon. Furthermore, it was concluded that the accumulated distilled water is 4600 mL/day and 4300 mL/day for theoretical and experimental examinations, respectively.

  20. Simulation and design of solar-blind Raman Lidar for water vapor measurement

    Science.gov (United States)

    Shi, Dongchen; Hua, Dengxin; Gao, Fei; Lei, Ning; Wang, Li

    2017-02-01

    A novel water vapor Raman Lidar is developed at a solar-blind wavelength of 266nm. To obtain signals of Mie-Rayleigh scattering spectra and Raman scattering spectra of H2O, N2 and O2 with fine separation and high efficient extraction, a newly high-efficiency Raman polychromatic system is designed using the combination of dichroic mirrors and narrow- band interference filters. Using the standard atmospheric scattering models and aerosol extinction coefficients, the rejection rate of Mie-Rayleigh scattering signals and the signal-to-noise ratio of atmospheric water vapor measurement are simulated. The optimal parameters of Lidar system are obtained based on the detailed analysis and the discussion of the SNR of echo signals. Lidar emission wavelength and Raman scattering echo wavelengths are all in the ultraviolet range below 300nm known as the "solar-blind" region, because practically all radiation at these wavelengths is absorbed by the ozone layer in the stratosphere. It has the advantage of detecting water vapor in the daytime without the influence of solar background radiation in the system. Through the comparison between the Raman Lidars at the wavelengths of 266nm and 355nm respectively, it is concluded that the detection performance of the designed system at 266nm is better than the Raman Lidar system at 355nm during the daytime measurement, and the measurement height can be up to the 4 km.

  1. Solar Desalination System Model for Sizing of Photovoltaic Reverse Osmosis (PVRO)

    KAUST Repository

    Habib, Abdulelah

    2015-06-28

    The focus of this paper is to optimize the solar energy utilization in the water desalination process. Due to variable nature of solar energy, new system design is needed to address this challenge. Here, reverse osmosis units, as the electrical loads, are considered as an ON/OFF units to track these solar energy variations. Reverse osmosis units are different in sizes and numbers. Various combinations of reverse osmosis units in size and capacity provide different water desalination system performances. To assess each scenario of reverse osmosis units, the total capital cost and operation and maintenance (O&M) cost are considered. The implemented optimization algorithm search all of the possible scenarios to find the best solution. This paper deploys the solar irradiance data which is provided from west coast (Red Sea) of Saudi Arabia for model construction and optimization algorithm implementation.

  2. The thermotidal exciting function for water vapour absorption of solar radiation

    Directory of Open Access Journals (Sweden)

    M. BONAFEDE

    1976-06-01

    Full Text Available The thermotidal exciting function J is considered, for
    the absorption of solar radiation by water vapour, according to the model
    derived by Siebert. The Mugge-Moller formula for water vapour absorption
    is integrated numerically, using experimental data for the water vapour
    concentration in the troposphere and the stratosphere. It appears that
    Siebort's formula is a reasonable approximation at low tropospheric levels
    but it dramatically overestimates the water vapour thermotidal heating
    in the upper troposphere and in the stratosphere. It seems thus possible
    that, if the correct vertical profile is employed for J , the amplitudes and
    phases of the diurnal temperature oscillations and of the tidal wind speeds
    may suffer significant changes from those previously calculated and possibly explain the three hours delay of the observed phases from the computed values.

  3. Simple solar systems for heating, hot water and cooking in high altitude regions with high solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C.; Schwarzer, K. [Solar-Inst., Juelich (Germany); Kleine-Hering, H. [Ecoandina, Salta (Argentina)

    2004-07-01

    In connection with a BMBF research project (FKZ 17104.01), a new system has been developed to provide solar heating and hot water. The system is designed to be used in areas with high solar radiation and low ambient temperatures, conditions which occur typically in high altitude regions. The main considerations in developing this system were robust technology, low cost and easy maintenance. To ensure robustness, air is used as the heat transfer medium. Air has the advantage of a low thermal capacity and enables the system to be immediately ready for use, and does not have the disadvantages of water at temperatures below the freezing point. The units were installed in two public buildings in the Argentinean Altiplano at an altitude of 3600 m, as part of a BMZ (Ministry for Cooperation) project. The local partner in the project was Ecoandina. Because of the high level of direct solar insolation in this area, concentrating solar cookers for families and institutions have a very high acceptance. As part of the BMZ project, four community cookers with Fixed-Focus reflectors (Scheffler reflectors) each with 3 kW power were installed. Further installations included solar hot water systems, drip irrigation systems with solar pumps and parabolic cookers for families. One of the villages equipped with these units is now to receive an award for being the first Solar Village in Argentina. (orig.)

  4. Predicting Solar Cycle 25 using Surface Flux Transport Model

    Science.gov (United States)

    Imada, Shinsuke; Iijima, Haruhisa; Hotta, Hideyuki; Shiota, Daiko; Kusano, Kanya

    2017-08-01

    It is thought that the longer-term variations of the solar activity may affect the Earth’s climate. Therefore, predicting the next solar cycle is crucial for the forecast of the “solar-terrestrial environment”. To build prediction schemes for the next solar cycle is a key for the long-term space weather study. Recently, the relationship between polar magnetic field at the solar minimum and next solar activity is intensively discussed. Because we can determine the polar magnetic field at the solar minimum roughly 3 years before the next solar maximum, we may discuss the next solar cycle 3years before. Further, the longer term (~5 years) prediction might be achieved by estimating the polar magnetic field with the Surface Flux Transport (SFT) model. Now, we are developing a prediction scheme by SFT model as a part of the PSTEP (Project for Solar-Terrestrial Environment Prediction) and adapting to the Cycle 25 prediction. The predicted polar field strength of Cycle 24/25 minimum is several tens of percent smaller than Cycle 23/24 minimum. The result suggests that the amplitude of Cycle 25 is weaker than the current cycle. We also try to obtain the meridional flow, differential rotation, and turbulent diffusivity from recent modern observations (Hinode and Solar Dynamics Observatory). These parameters will be used in the SFT models to predict the polar magnetic fields strength at the solar minimum. In this presentation, we will explain the outline of our strategy to predict the next solar cycle and discuss the initial results for Cycle 25 prediction.

  5. The influence of the solar radiation model on the calcutated solar radiation from a horizontal surface to a tilted surface

    DEFF Research Database (Denmark)

    Andersen, Elsa; Lund, Hans; Furbo, Simon

    2004-01-01

    in the calculation. The weather data are measured at the solar radiation measurement station, SMS at the Department of Civil Engineering at the Technical University of Denmark. In this study the weather data are combined with solar collector calculations based on solar collector test carried out at Solar Energy......Measured solar radiation data are most commonly available as total solar radiation on a horizontal surface. When using solar radiation measured on horizontal to calculate the solar radiation on tilted surfaces and thereby the thermal performance of different applications such as buildings and solar...... heating systems, different solar radiation models can be used. The calculation of beam radiation from a horizontal surface to a tilted surface can be done exactly whereas different solar radiation models can calculate the sky diffuse radiation. The sky diffuse radiation can either be assumed evenly...

  6. Finite element modelling and simulation of free convection heat transfer in solar oven

    Energy Technology Data Exchange (ETDEWEB)

    Sobamowo, M.G.; Ogunmola, B.Y.; Ayerin A.M. [Department of Mechanical Engineering, University of Lagos, Akoka, Lagos (Nigeria)

    2013-07-01

    The use of solar energy for baking, heating or drying represents a sustainable way of solar energy applications with negligible negative effects. Solar oven is an alternative to conventional oven that rely heavily on coal and wood or Electric oven that uses the power from the National grid of which the end users have little or no control. Since the Solar oven uses no fuel and it costs nothing to run, it uses are widely promoted especially in situations where minimum fuel consumption or fire risks are considered highly important. As useful as the Solar Oven proved, it major setback in the area of applications has been its future sustainability. For the use of Solar Oven/Cookers to be sustained in the future, the design and development of solar oven must rely on sound analytical tools. Therefore, this work focused on the design and development of the solar oven. To test the performance of the Small Solar Oven a 5000cm3 beaker of water was put into the Oven and the temperature of the water was found to reach 810C after about 3hrs under an average ambient temperature of 300C. On no load test, the oven reached a maximum temperature of 112oC in 6hrs. In order to carry out the parametric studies and improve the performance of the Solar Oven, Mathematical models were developed and solved by using Characteristics-Based Split (CBS) Finite Element Method. The Model results were compared with the Experimental results and a good agreement was found between the two results.

  7. Finite element modelling and simulation of free convection heat transfer in solar oven

    Directory of Open Access Journals (Sweden)

    Sobamowo M.G., Ogunmola B.Y., Ayerin A. M.

    2014-01-01

    Full Text Available The use of solar energy for baking, heating or drying represents a sustainable way of solar energy applications with negligible negative effects. Solar oven is an alternative to conventional oven that rely heavily on coal and wood or Electric oven that uses the power from the National grid of which the end users have little or no control. Since the Solar oven uses no fuel and it costs nothing to run, it uses are widely promoted especially in situations where minimum fuel consumption or fire risks are considered highly important. As useful as the Solar Oven proved, it major setback in the area of applications has been its future sustainability. For the use of Solar Oven/Cookers to be sustained in the future, the design and development of solar oven must rely on sound analytical tools. Therefore, this work focused on the design and development of the solar oven. To test the performance of the Small Solar Oven a 5000cm3 beaker of water was put into the Oven and the temperature of the water was found to reach 810C after about 3hrs under an average ambient temperature of 300C. On no load test, the oven reached a maximum temperature of 112oC in 6hrs. In order to carry out the parametric studies and improve the performance of the Solar Oven, Mathematical models were developed and solved by using Characteristics-Based Split (CBS Finite Element Method. The Model results were compared with the Experimental results and a good agreement was found between the two results.

  8. Water use and supply concerns for utility-scale solar projects in the Southwestern United States.

    Energy Technology Data Exchange (ETDEWEB)

    Klise, Geoffrey Taylor; Tidwell, Vincent Carroll; Reno, Marissa Devan; Moreland, Barbara Denise.; Zemlick, Katie M.; Macknick, Jordan

    2013-07-01

    As large utility-scale solar photovoltaic (PV) and concentrating solar power (CSP) facilities are currently being built and planned for locations in the U.S. with the greatest solar resource potential, an understanding of water use for construction and operations is needed as siting tends to target locations with low natural rainfall and where most existing freshwater is already appropriated. Using methods outlined by the Bureau of Land Management (BLM) to determine water used in designated solar energy zones (SEZs) for construction and operations & maintenance, an estimate of water used over the lifetime at the solar power plant is determined and applied to each watershed in six Southwestern states. Results indicate that that PV systems overall use little water, though construction usage is high compared to O&M water use over the lifetime of the facility. Also noted is a transition being made from wet cooled to dry cooled CSP facilities that will significantly reduce operational water use at these facilities. Using these water use factors, estimates of future water demand for current and planned solar development was made. In efforts to determine where water could be a limiting factor in solar energy development, water availability, cost, and projected future competing demands were mapped for the six Southwestern states. Ten watersheds, 9 in California, and one in New Mexico were identified as being of particular concern because of limited water availability.

  9. Producing propellants from water in lunar soil using solar lasers

    Science.gov (United States)

    de Morais Mendonca Teles, Antonio

    The exploration of the Solar System is directly related to the efficiency of engines designed to explore it, and consequently, to the propulsion techniques, materials and propellants for those engines. With the present day propulsion techniques it is necessary great quantities of propellants to impulse a manned spacecraft to Mars and beyond in the Solar System, which makes these operations financially very expensive because of the costs involved in launching it from planet Earth, due to its high gravity field strength. To solve this problem, it is needed a planetary place with smaller gravity field strength, near to the Earth and with great quantities of substances at the surface necessary for the in-situ production of propellants for spacecrafts. The only place available is Earth's natural satellite the Moon. So, here in this paper, I propose the creation of a Lunar Propellant Manufacturer. It is a robot-spacecraft which can be launched from Earth using an Energia Rocket, and to land on the Moon in an area (principally near to the north pole where it was discovered water molecules ice recently) with great quantities of oxygen and hydrogen (propellants) in the silicate soil, previously observed and mapped by spacecrafts in lunar orbit, for the extraction of those molecules from the soil and the in-situ production of the necessary propellants. The Lunar Propellant Manufacturer (LPM) spacecraft consists of: 1) a landing system with four legs (extendable) and rovers -when the spacecraft touches down, the legs retract in order that two apparatuses, analogue to tractor's wheeled belts parallel sided and below the spacecraft, can touch firmly the ground -it will be necessary for the displacement of the spacecraft to new areas with richer propellants content, when the early place has already exhausted in propellants; 2) a digging machine -a long, resistant extendable arm with an excavator hand, in the outer part of the spacecraft -it will extend itself to the ground

  10. Development of a Stochastic Hourly Solar Irradiation Model

    Directory of Open Access Journals (Sweden)

    Kristijan Brecl

    2014-01-01

    Full Text Available We have developed a new solar irradiation model and implemented it in the SunIrradiance photovoltaic cell/module simulator. This model uses stochastic methods to generate the hourly distribution of solar irradiation on a horizontal or inclined surface from monthly irradiation values on the horizontal surface of a selected location and was verified with the measured irradiance data in Ljubljana, located in Central Europe. The new model shows better simulation results with regard to the share of the diffuse irradiation in the region than the other models. The simulation results show that the new solar irradiation model is excellent for photovoltaic system simulations of single junction PV technologies.

  11. Final report : testing and evaluation for solar hot water reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Caudell, Thomas P. (University of New Mexico, Albuquerque, NM); He, Hongbo (University of New Mexico, Albuquerque, NM); Menicucci, David F. (Building Specialists, Inc., Albuquerque, NM); Mammoli, Andrea A. (University of New Mexico, Albuquerque, NM); Burch, Jay (National Renewable Energy Laboratory, Golden CO)

    2011-07-01

    Solar hot water (SHW) systems are being installed by the thousands. Tax credits and utility rebate programs are spurring this burgeoning market. However, the reliability of these systems is virtually unknown. Recent work by Sandia National Laboratories (SNL) has shown that few data exist to quantify the mean time to failure of these systems. However, there is keen interest in developing new techniques to measure SHW reliability, particularly among utilities that use ratepayer money to pay the rebates. This document reports on an effort to develop and test new, simplified techniques to directly measure the state of health of fielded SHW systems. One approach was developed by the National Renewable Energy Laboratory (NREL) and is based on the idea that the performance of the solar storage tank can reliably indicate the operational status of the SHW systems. Another approach, developed by the University of New Mexico (UNM), uses adaptive resonance theory, a type of neural network, to detect and predict failures. This method uses the same sensors that are normally used to control the SHW system. The NREL method uses two additional temperature sensors on the solar tank. The theories, development, application, and testing of both methods are described in the report. Testing was performed on the SHW Reliability Testbed at UNM, a highly instrumented SHW system developed jointly by SNL and UNM. The two methods were tested against a number of simulated failures. The results show that both methods show promise for inclusion in conventional SHW controllers, giving them advanced capability in detecting and predicting component failures.

  12. Alive and well: a short review about standard solar models

    CERN Document Server

    Serenelli, Aldo

    2016-01-01

    Standard solar models (SSMs) provide a reference framework across a number of research fields: solar and stellar models, solar neutrinos, particle physics the most conspicuous among them. The accuracy of the physical description of the global properties of the Sun that SSMs provide has been challenged in the last decade by a number of developments in stellar spectroscopic techniques. Over the same period of time, solar neutrino experiments, and Borexino in particular, have measured the four solar neutrino fluxes from the pp-chains that are associated with 99\\% of the nuclear energy generated in the Sun. Borexino has also set the most stringent limit on CNO energy generation, only $\\sim 40\\%$ larger than predicted by SSMs. More recently, and for the first time, radiative opacity experiments have been performed at conditions that closely resemble those at the base of the solar convective envelope. In this article, we review these developments and discuss the current status of SSMs, including its intrinsic limit...

  13. Alive and well: A short review about standard solar models

    Energy Technology Data Exchange (ETDEWEB)

    Serenelli, Aldo [Campus UAB, Carrer de Can Magrans S/N, Instituto de Ciencias del Espacio (ICE/CSIC-IEEC), Cerdanyola del Valles (Spain)

    2016-04-15

    Standard solar models (SSMs) provide a reference framework across a number of research fields: solar and stellar models, solar neutrinos, particle physics the most conspicuous among them. The accuracy of the physical description of the global properties of the Sun that SSMs provide has been challenged in the last decade by a number of developments in stellar spectroscopic techniques. Over the same period of time, solar neutrino experiments, and Borexino in particular, have measured the four solar neutrino fluxes from the pp-chains that are associated with 99% of the nuclear energy generated in the Sun. Borexino has also set the most stringent limit on CNO energy generation, only ∝ 40% larger than predicted by SSMs. More recently, and for the first time, radiative opacity experiments have been performed at conditions that closely resemble those at the base of the solar convective envelope. In this article, we review these developments and discuss the current status of SSMs, including its intrinsic limitations. (orig.)

  14. How mixing during hot water draw-offs influence the thermal performance of small solar domestic hot water systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Shah, Louise Jivan

    2005-01-01

    CFD calculations on the mixing during hot water draw-offs in vertical hot water tanks with different diameters have been carried out. The calculations, which were carried out with the same cold water inlet design, showed that the extent of mixing is strongly influenced by the tank diameter....... The extent of mixing is increasing for increasing tank diameter. Further, calculations of the yearly thermal performance of small solar domestic hot water systems with hot water tanks with different mixing rates during hot water draw-offs were carried out. Both solar domestic hot water systems with mantle......, and that a decreased auxiliary volume in the tanks and an increased height/diameter ratio of the tanks will increase the thermal performance of the systems. The investigations showed further, that mixing during hot water draw-offs decreases the thermal performance of solar domestic hot water systems. The mixing...

  15. Feasibility study of a solar photovoltaic water pumping system for rural Ethiopia

    Directory of Open Access Journals (Sweden)

    Misrak Girma

    2015-06-01

    Full Text Available Solar Photovoltaic (SPV water pumping system is one of the best technologies that utilize the solar energy to pump water from deep well underground water sources and to provide clean drinking water worldwide. The availability of abundant solar radiation and enough underground water sources in Ethiopia can be combined together to make clean drinking water available to rural communities. The software PVsyst 5.56 was used to study the feasibility of solar photovoltaic water pumping system in the selected sites. The designed system is capable of providing a daily average of 10.5, 7 and 6.5 m3/day for 700, 467 and 433 people in Siadberand Wayu, Wolmera and Enderta sites respectively, with average daily water consumption of 15 liters per day per person and the costs of water without any subsidy, are approximately 0.1, 0.14 and 0.16 $/m3for each site respectively. If diesel generator is used instead of solar photovoltaic water pumping system, to provide the same average daily water for the selected community, the costs of water without any subsidy are approximately 0.2, 0.23 and 0.27 $/m3 for each site respectively. A life cycle cost analysis method was also carried out for economic comparison between solar PV and the diesel pumping system. The results of this study are encouraging the use of the PV system for drinking water supply in the remote areas of the country.

  16. Solar Spectral Irradiance Variability in Cycle 24: Observations and Models

    CERN Document Server

    Marchenko, S V; Lean, J L

    2016-01-01

    Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI), we characterize both short-term (solar rotation) and long-term (solar cycle) changes of the solar spectral irradiance (SSI) between 265-500 nm during the on-going Cycle 24. We supplement the OMI data with concurrent observations from the GOME-2 and SORCE instruments and find fair-to-excellent, depending on wavelength, agreement among the observations and predictions of the NRLSSI2 and SATIRE-S models.

  17. Thermal performance of a photographic laboratory process: Solar Hot Water System

    Science.gov (United States)

    Walker, J. A.; Jensen, R. N.

    1982-01-01

    The thermal performance of a solar process hot water system is described. The system was designed to supply 22,000 liters (5,500 gallons) per day of 66 C (150 F) process water for photographic processing. The 328 sq m (3,528 sq. ft.) solar field has supplied 58% of the thermal energy for the system. Techniques used for analyzing various thermal values are given. Load and performance factors and the resulting solar contribution are discussed.

  18. Water Stress Projection Modeling

    Science.gov (United States)

    2016-09-01

    facility. Stationing analysis done with climate forecasting in mind recognizes an unpredictable future, while striving to best prepare for the...to support additional growth. This attribute places a threshold ca- pacity on water supply and treatment, which may be related to treat- ment plant ...et al. 2013). 3.3 Military impacts reduced water Extreme weather events such as droughts, floods, snow, and ice storms have significant impacts on

  19. Ensemble prediction model of solar proton events associated with solar flares and coronal mass ejections

    Institute of Scientific and Technical Information of China (English)

    Xin Huang; Hua-Ning Wang; Le-Ping Li

    2012-01-01

    An ensemble prediction model of solar proton events (SPEs),combining the information of solar flares and coronal mass ejections (CMEs),is built.In this model,solar flares are parameterized by the peak flux,the duration and the longitude.In addition,CMEs are parameterized by the width,the speed and the measurement position angle.The importance of each parameter for the occurrence of SPEs is estimated by the information gain ratio.We find that the CME width and speed are more informative than the flare's peak flux and duration.As the physical mechanism of SPEs is not very clear,a hidden naive Bayes approach,which is a probability-based calculation method from the field of machine learning,is used to build the prediction model from the observational data.As is known,SPEs originate from solar flares and/or shock waves associated with CMEs.Hence,we first build two base prediction models using the properties of solar flares and CMEs,respectively.Then the outputs of these models are combined to generate the ensemble prediction model of SPEs.The ensemble prediction model incorporating the complementary information of solar flares and CMEs achieves better performance than each base prediction model taken separately.

  20. Excystation of Cryptosporidium parvum at temperatures that are reached during solar water disinfection.

    Science.gov (United States)

    Gómez-Couso, H; Fontán-Sainz, M; Fernández-Alonso, J; Ares-Mazás, E

    2009-04-01

    Species belonging to the genera Cryptosporidium are recognized as waterborne pathogens. Solar water disinfection (SODIS) is a simple method that involves the use of solar radiation to destroy pathogenic microorganisms that cause waterborne diseases. A notable increase in water temperature and the existence of a large number of empty or partially excysted (i.e. unviable) oocysts have been observed in previous SODIS studies with water experimentally contaminated with Cryptosporidium parvum oocysts under field conditions. The aim of the present study was to evaluate the effect of the temperatures that can be reached during exposure of water samples to natural sunlight (37-50 degrees C), on the excystation of C. parvum in the absence of other stimuli. In samples exposed to 40-48 degrees C, a gradual increase in the percentage of excystation was observed as the time of exposure increased and a maximum of 53.81% of excystation was obtained on exposure of the water to a temperature of 46 degrees C for 12 h (versus 8.80% initial isolate). Under such conditions, the oocyst infectivity evaluated in a neonatal murine model decreased statistically with respect to the initial isolate (19.38% versus 100%). The results demonstrate the important effect of the temperature on the excystation of C. parvum and therefore on its viability and infectivity.

  1. Solar disinfection of water for low income communities; Desinfeccao solar de agua para comunidades de baixa renda

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Lorna Falcao

    2010-03-15

    The use of solar energy for water disinfection, and is accessible to disadvantaged communities because of its low cost, has the advantage of using disposable materials such as bottles of polyethylene terephthalate (PET). We present a study that used two methods of disinfection: the methodology proposed by the project Solar Water Disinfection (SODIS), which consisted of water disinfection by solar radiation and temperature and the methodology which the temperature of the water for disinfection. In both, we seek to eliminate microorganisms that cause serious diseases such as dysentery, typhoid, cholera, etc. Water samples were collected in the community of Bass, where the population has low income and the incidence of waterborne diseases is high. The experiments were divided into two stages. In step 1 we studied the feasibility of disinfection and in step 2 the feasibility of the pilot plant to obtain adequate levels of disinfection temperatures desired. The results showed the efficiency of the disinfection process, reaching an average of 80 to 100% death of microorganisms, but regrowth was observed in some samples. Finally on the good results of stage 1, is designed and built and tested in an experimental pilot plant, which has shown to be feasible to promote water disinfection through the use of solar energy. The water after treatment is in accordance with the limits established by Brazilian legislation for clean water, maintaining a positive performance for the disinfection and acceptable levels of bacterial regrowth. (author)

  2. Application of the genetic algorithm for optimisation of large solar hot water systems

    NARCIS (Netherlands)

    Loomans, M.G.L.C.; Visser, H.

    2002-01-01

    An implementation of the genetic algorithm in a design support tool for (large) solar hot water systems is described. The tool calculates the yield and the costs of solar hot water systems based on technical and financial data of the system components. The genetic algorithm allows for optimisation o

  3. Application of the genetic algorithm for optimisation of large solar hot water systems

    NARCIS (Netherlands)

    Loomans, M.G.L.C.; Visser, H.

    2002-01-01

    An implementation of the genetic algorithm in a design support tool for (large) solar hot water systems is described. The tool calculates the yield and the costs of solar hot water systems based on technical and financial data of the system components. The genetic algorithm allows for optimisation

  4. A rhetorical investigation of energy-related environmental issues and a proposed modeling of variables influencing the employment of domestic solar water heaters with a focus on mobilizing information

    Science.gov (United States)

    Garner, Lilla Gayle

    how the variables and information identified in the rhetorical investigation might be actualized in the construction of messages related to a particular consumer energy behavior, the proposed modeling of variables is used as a framework for a heuristic experimental study. This experimental study is designed to test the influence of one particular variable found at the beliefs level---action strategies and skills, or mobilizing information---on consumers' attitudes and intentions to behave toward a specific energy-related topic, the employment of domestic solar water heaters.

  5. Verification of high-speed solar wind stream forecasts using operational solar wind models

    CERN Document Server

    Reiss, Martin A; Veronig, Astrid M; Nikolic, Ljubomir; Vennerstrom, Susanne; Schoengassner, Florian; Hofmeister, Stefan J

    2016-01-01

    High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the ACE spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation between the coronal hole area observed in Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images and solar wind properties at the near-Earth environment, the WSA model establishes a link between properties of the open magnetic field lines extending from the photosphere to the corona and the background solar wind conditions. We found that both solar wind models are capable of predicting the large-scale features of the observed sol...

  6. Effect of hot-water consumption on temperature distribution in a horizontal solar water storage tank

    Energy Technology Data Exchange (ETDEWEB)

    Helwa, N.H.; El-Ghetany, H.H. [National Research Center, Cairo (Egypt). Dept. of Solar Energy; Mobarak, A.M.; El-Sallak, M.S. [Cairo Univ. (Egypt). Dept. of Mechanical Engineering

    1995-12-31

    This experimental investigation assesses the behaviour of a solar water heater provided with a liquid heat exchanger in a horizontal storage tank. The factors that affect the stratification inside the storage tank are considered. The performance of the system is studied in the light of the daily consumption of hot water of an Egyptian family. The results obtained show that in the places where it is necessary to use a horizontal tank it must be supplied with an auxiliary electric heater to meet the required load at the required temperature, especially in winter. (author)

  7. Establishing solar water disinfection as a water treatment method at household level

    Directory of Open Access Journals (Sweden)

    Regula Meierhofer

    2006-12-01

    Full Text Available 1.1 billion People worldwide do not have access to safe drinking water and therefore are exposed to a high risk for diarrhoeal diseases. As a consequence, about 6,000 children die each day of dehydration due to diarrhoea. Adequate water treatment methods and safe storage of drinking water, combined with hygiene promotion, are required to prevent the population without access to safe drinking water from illness and death. Solar water disinfection (SODIS is a new water treatment to be applied at household level with a great potential to reduce diarrhoea incidence of users. The method is very simple and the only resources required for its application are transparent PET plastic bottles (or glass bottles and sufficient sunlight: microbiologically contaminated water is filled into the bottles and exposed to the full sunlight for 6 hours. During solar exposure, the diarrhoea causing pathogens are killed by the UV-A radiation of the sunlight. At present, SODIS is used by about 2 Million users in more than 20 countries of the South. Diarrhoea incidence of users significantly has been reduced by 30 to 70 %. A careful and long-term community education process that involves creating awareness on the importance of treating drinking water and initiates behaviour change is required to establish the sustainable practice of SODIS at community level. In Madagascar, more than 160 children younger than 5 years die each day from malaria, diarrhoea and acute respiratory illnesses. The application of household water treatment methods such as SODIS significantly could contribute to improve their health.

  8. Implications of Topographically Induced Variations in Solar Radiation for Water Balance, Vegetation and Soil Development.

    Science.gov (United States)

    Seyfried, M. S.; Flerchinger, G. N.; Link, T. E.; McNamara, J. P.

    2016-12-01

    Vegetation cover and stature in semiarid regions are highly sensitive to variations in evaporative demand and precipitation. Where the terrain is complex, this may result in a spatial mosaic of vegetation cover related to topographically induced variations in solar radiation and hence evaporative demand. The associated energy and water fluxes and carbon stocks probably do not scale linearly, but are potentially predictable. Johnston Draw, a small, semiarid, granitic catchment in the Reynolds Creek Experimental Watershed in Idaho, is dominated by steep north and south-facing slopes. Vegetation on North-facing slopes is more complete. We made spatially extensive, periodic measurements of soil temperature (Ts) soil water content (Ws) to establish the spatial variability of those parameters. In addition, we monitored Ts and Ws in profiles to bedrock, snow depth and meteorological parameters at three paired, north- and south-facing slope locations. These data were compared to simulations of water and energy flux calculated using the Simultaneous Heat and Water (SHAW) model. We found dramatic differences in Ts, with the annual average soil temperature about 5 C warmer on south-facing slopes. Differences varied seasonally, with the biggest differences in the summer, exactly out of phase with the solar radiation differences. Each year soils dried to consistent, low values, but the north-facing soils retained water about one month longer, on average, owing mostly to the greater depth, and hence available water, on those soils. Modeling results indicate that water is retained longer in north-facing soils and the differences in Ts are due to differences in soil cover, primarily from the greater density of vegetative cover. These differences appear to have evolved over time as the result of feedbacks between atmospheric forcings and vegetation response, which promote greater carbon accumulations and deeper soil formation.

  9. Magneto-Vortex Dynamo Model in Solar convection zone

    CERN Document Server

    Ershkov, Sergey V

    2011-01-01

    Here is presented a new magneto-vortex dynamo model for modeling & predicting of a processes in Solar plasma convection zone. Solar convection zone is located above the level r > 0,6-0,7 R, where R is a Solar radius. A key feature of such a model is that equation of Solar plasma motion as well as equation of magnetic fields evolution - are reduced to Helmholtz's vortex equation, which is up-graded in according with alpha-effect (Coriolis force forms an additional vorticity field or magnetic field due to Sun's differential rotation). Such an additional vorticity or magnetic field are proved to be concentrated at the proper belt in Solar convection zone under the influence of Coriolis force (at the middle latitudes of the Sun in respect to equator). Besides, such an an additional vorticity & magnetic fields are to be the basic sources of well-known phenomena "Maunder's butterfly" diagram.

  10. DETAILED MODELLING OF CHARGING BEHAVIOUR OF SMART SOLAR TANKS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Andersen, Elsa; Furbo, Simon

    2010-01-01

    The charging behaviour of smart solar tanks for solar combisystems for one-family houses is investigated with detailed Computational Fluid Dynamics (CFD) modelling and Particle Image Velocimetry (PIV) measurements. The smart solar tank can be charged with a variable auxiliary volume fitted...... to the expected future energy demand. Therefore the heat loss from the tank is decreased and the thermal performance of the solar heating system is increased compared to a traditional system with a fixed auxiliary volume. The solar tank can be charged either by an electric heating element situated in the tank...... or by an electric heating element in a side-arm mounted on the side of the tank. Detailed CFD models of the smart tanks are built with different mesh densities in the tank and in the side-arm. The thermal conditions of the tank during charging are calculated with the CFD models. The fluid flow and temperature...

  11. DETAILED MODELLING OF CHARGING BEHAVIOUR OF SMART SOLAR TANKS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Andersen, Elsa; Furbo, Simon

    The charging behaviour of smart solar tanks for solar combisystems for one-family houses is investigated with detailed Computational Fluid Dynamics (CFD) modelling and Particle Image Velocimetry (PIV) measurements. The smart solar tank can be charged with a variable auxiliary volume fitted...... to the expected future energy demand. Therefore the heat loss from the tank is decreased and the thermal performance of the solar heating system is increased compared to a traditional system with a fixed auxiliary volume. The solar tank can be charged either by an electric heating element situated in the tank...... or by an electric heating element in a side-arm mounted on the side of the tank. Detailed CFD models of the smart tanks are built with different mesh densities in the tank and in the side-arm. The thermal conditions of the tank during charging are calculated with the CFD models. The fluid flow and temperature...

  12. Solar Deployment System (SolarDS) Model: Documentation and Sample Results

    Energy Technology Data Exchange (ETDEWEB)

    Denholm, P.; Drury, E.; Margolis, R.

    2009-09-01

    The Solar Deployment System (SolarDS) model is a bottom-up, market penetration model that simulates the potential adoption of photovoltaics (PV) on residential and commercial rooftops in the continental United States through 2030. NREL developed SolarDS to examine the market competitiveness of PV based on regional solar resources, capital costs, electricity prices, utility rate structures, and federal and local incentives. The model uses the projected financial performance of PV systems to simulate PV adoption for building types and regions then aggregates adoption to state and national levels. The main components of SolarDS include a PV performance simulator, a PV annual revenue calculator, a PV financial performance calculator, a PV market share calculator, and a regional aggregator. The model simulates a variety of installed PV capacity for a range of user-specified input parameters. PV market penetration levels from 15 to 193 GW by 2030 were simulated in preliminary model runs. SolarDS results are primarily driven by three model assumptions: (1) future PV cost reductions, (2) the maximum PV market share assumed for systems with given financial performance, and (3) PV financing parameters and policy-driven assumptions, such as the possible future cost of carbon emissions.

  13. Helicity of Solar Active Regions from a Dynamo Model

    Indian Academy of Sciences (India)

    Piyali Chatterjee

    2006-06-01

    We calculate helicities of solar active regions based on the idea that poloidal flux lines get wrapped around a toroidal flux tube rising through the convection zone, thereby giving rise to the helicity. We use our solar dynamo model based on the Babcock–Leighton -effect to study how helicity varies with latitude and time.

  14. Magnetosonic Waveguide Model of Solar Wind Flow Tubes

    Indian Academy of Sciences (India)

    A. K. Srivastava; B. N. Dwivedi

    2006-06-01

    We consider solar wind flow tubes as a magnetosonic wave-guide. Assuming a symmetric expansion in edges of slab-modelled wave-guide, we study the propagation characteristics of magnetosonic wave in the solar wind flow tubes. We present the preliminary results and discuss their implications.

  15. How mixing during hot water draw-offs influence the thermal performance of small solar domestic hot water systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Shah, Louise Jivan

    2005-01-01

    CFD calculations on the mixing during hot water draw-offs in vertical hot water tanks with different diameters have been carried out. The calculations, which were carried out with the same cold water inlet design, showed that the extent of mixing is strongly influenced by the tank diameter. The e...... consideration of the required hot water comfort.......CFD calculations on the mixing during hot water draw-offs in vertical hot water tanks with different diameters have been carried out. The calculations, which were carried out with the same cold water inlet design, showed that the extent of mixing is strongly influenced by the tank diameter....... The extent of mixing is increasing for increasing tank diameter. Further, calculations of the yearly thermal performance of small solar domestic hot water systems with hot water tanks with different mixing rates during hot water draw-offs were carried out. Both solar domestic hot water systems with mantle...

  16. Glycol/water evacuated-tube solar collector

    Science.gov (United States)

    1980-01-01

    Report describes performance of 8 tube and 10 tube commercially produced solar collectors. Tests include thermal efficiency, time constant for temperature drop after solar flux is cut, change in efficiency with Sun angle, and temperature rise if circulation is stopped.

  17. Comparison of Columnar Water Vapor Measurements During The Fall 1997 ARM Intensive Observation Period: Solar Transmittance Methods

    Science.gov (United States)

    Schmid, B.; Michalsky, J. J.; Slater, D. W.; Barnard, J. C.; Halthore, R. N.; Liljegren, J. C.; Holben, B. N.; Eck, T. F.; Livingston, J. M.; Russell, P. B.

    2000-01-01

    In the fall of 1997, during an Intensive Observation Period (IOP), the Atmospheric Radiation Measurement (ARM) program conducted a study of water vapor abundance measurement at its Southern Great Plains (SGP) site. Among a large number of instruments, four sun-tracking radiometers were present to measure the columnar water vapor (CWV). All four solar radiometers retrieve CWV by measuring total solar transmittance in the 0.94-gm water vapor absorption band and subtracting contributions due to Rayleigh, ozone and aerosol transmittances. The aerosol optical depth comparisons among the same four radiometers has been presented elsewhere (Geophys. Res. Lett., 26, 17, 2725-2728, 1999). We have used three different methods to retrieve CWV. In a first round of comparison no attempt was made to standardize on the same radiative transfer model and its underlying water vapor spectroscopy. In the second round of comparison we used the same line-by-line code (which includes recently corrected H2O spectroscopy) to retrieve CAN from all four suntracking radiometers. This decreased the mean CWV by 8% or 13%. The spread of 8% in the solar radiometer results found when using the same model is an indication of the other-than-model uncertainties involved in determining CWV from solar transmittance measurements with current instrumentation.

  18. Thermodynamic simulation of solar/gas hybrid system os water sea desalination; Simulacion termodinamica de un sistema hibrido solar/gas de desalacion de agua de mar

    Energy Technology Data Exchange (ETDEWEB)

    Alarcon, D.; Blanco, J.; Sanchez, B.; Malato, S.; Maldonado, M. I.; Fernandez, P.

    2004-07-01

    Desalination of seawater is one of the most promising applications of solar thermal energy and one of the possible solutions to the water stress the planet is now undergoing. This paper shows the different solar desalination system configurations that have been studied during the research phase of AQUASOL European Project (EVK1-CT2001-00102). These configurations have been modeled and the analysis of the corresponding simulations has allowed determining the approximate temperatures and flow rates obtained in the various subsystems. The choice of the best configuration can only be made after the system has been installed at the Plataforma Solar de Almeria and its experimental evaluation in the demonstration phase of the project. (Author)

  19. Optofluidic planar reactors for photocatalytic water treatment using solar energy

    Science.gov (United States)

    Lei, Lei; Wang, Ning; Zhang, X. M.; Tai, Qidong; Tsai, Din Ping; Chan, Helen L. W.

    2010-01-01

    Optofluidics may hold the key to greater success of photocatalytic water treatment. This is evidenced by our findings in this paper that the planar microfluidic reactor can overcome the limitations of mass transfer and photon transfer in the previous photocatalytic reactors and improve the photoreaction efficiency by more than 100 times. The microreactor has a planar chamber (5 cm×1.8 cm×100 μm) enclosed by two TiO2-coated glass slides as the top cover and bottom substrate and a microstructured UV-cured NOA81 layer as the sealant and flow input∕output. In experiment, the microreactor achieves 30% degradation of 3 ml 3×10−5M methylene blue within 5 min and shows a reaction rate constant two orders higher than the bulk reactor. Under optimized conditions, a reaction rate of 8% s−1 is achieved under solar irradiation. The average apparent quantum efficiency is found to be only 0.25%, but the effective apparent quantum efficiency reaches as high as 25%. Optofluidic reactors inherit the merits of microfluidics, such as large surface∕volume ratio, easy flow control, and rapid fabrication and offer a promising prospect for large-volume photocatalytic water treatment. PMID:21267436

  20. Water Purification and Disinfection by using Solar Energy: Towards Green Energy Challenge

    Directory of Open Access Journals (Sweden)

    Md Z.H. Khan

    2015-12-01

    Full Text Available The aim of this work was to design a solar water treatment plant for household purpose. Water purification is the process of eradicating detrimental chemicals, biological poisons, suspended solids and gases from contaminated water. In this work we have reported an investigation of compact filter which is cost effective for developing countries and ease of maintenance. We have arranged a solar water disinfection system that improves the microbiological quality of drinking water at household level. We get 14 L pure water and 16 ml water vapour within 240 min by using filtration method. From our work we get hot water up to 49°C. The efficiency of the system at sunny days and cloudy days are 18.23% and 18.13% respectively. This simple solar hybrid system helps to remove turbidity as well as chemical and pathogenic contaminants from water sources in the most affordable, and expedient manner possibly.

  1. Modeling Water Filtration

    Science.gov (United States)

    Parks, Melissa

    2014-01-01

    Model-eliciting activities (MEAs) are not new to those in engineering or mathematics, but they were new to Melissa Parks. Model-eliciting activities are simulated real-world problems that integrate engineering, mathematical, and scientific thinking as students find solutions for specific scenarios. During this process, students generate solutions…

  2. Solar heating and hot water system installed at Saint Louis, Missouri

    Science.gov (United States)

    1980-01-01

    The solar heating and hot water system installed at the William Tao & Associates, Inc., office building in St. Louis, Missouri is described, including maintenance and construction problems, final drawings, system requirements, and manufacturer's component data. The solar system was designed to provide 50 percent of the hot water requirements and 45 percent of the space heating needs for a 900 sq ft office space and drafting room. The solar facility has 252 sq ft of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

  3. Solar heating and hot water system installed at St. Louis, Missouri. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-04-01

    Information is provided on the solar heating and hot water system installed at the William Tao and Associates, Inc., office building in St. Louis, Missouri. The information consists of description, photos, maintenance and construction problems, final drawing, system requirements and manufacturer's component data. The solar system was designed to provide 50% of the hot water requirements and 45% of the space heating needs for a 900 square foot office space and drafting room. The solar facility has 252 square foot of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

  4. Energetic Performances Study of an Integrated Collector Storage Solar Water Heater

    Directory of Open Access Journals (Sweden)

    O. Helal

    2010-01-01

    Full Text Available Problem statement: Although that the interest attributed to the solar energy remains relatively limited, we attend today to the conception of several installations using the sun as energy source among which we quote the solar water heater. Approach: A study of energetic performances was taken on an integrated collector/storage solar water heater made in the National School of Engineers of Gabes. This water heater is equipped with a concentration system containing a reflector composed of three parabolic branches favorating a better absorption of solar radiance. Results: The comparison between this system and two other systems of solar water heater, composed of a storage ball with asymmetrical CPC and symmetrical CPC, showed important energetic performances despite the simplicity and the little cost of the collector. Conclusion: Several improvements are necessary to increase the direct flow whilst decrease the thermal losses and therefore make the system simpler to be installed on the building roof.

  5. Analysis of a Residential Heating System Utilizing a Solar Assisted Water-to-Air Heat Pump.

    Science.gov (United States)

    1979-07-01

    heat pump heating system were analyzed. A realistic residence and solar assisted water-to-air heat pump system were modeled for this northern climate using the transient simulation computer code TRNSYS developed by the University of Wisconsin. The system was studied over a one month winter period, December, using actual hourly weather data. The system was analyzed for both the cloudiest and clearest December weather recorded in the last 30 years. The collector area and storage tank capacity were varied and the effects on system performance were

  6. Experimental Analysis of Desalination Unit Coupled with Solar Water Lens Concentrator

    Science.gov (United States)

    Chaithanya, K. K.; Rajesh, V. R.; Suresh, Rahul

    2016-09-01

    The main problem that the world faces in this scenario is shortage of potable water. Hence this research work rivets to increase the yield of desalination system in an economical way. The integration of solar concentrator and desalination unit can project the desired yield, but the commercially available concentrated solar power technologies (CSP) are not economically viable. So this study proposes a novel method to concentrate ample amount of solar radiation in a cost effective way. Water acting as lens is a highlighted technology initiated in this work, which can be a substitute for CSP systems. And water lens can accelerate the desalination process so as to increase the yield economically. The solar irradiance passing through the water will be concentrated at a focal point, and the concentration depends on curvature of water lens. The experimental analysis of water lens makes use of transparent thin sheet, supported on a metallic structure. The Plano convex shape of water lens is developed by varying the volume of water that is being poured on the transparent thin sheet. From the experimental analysis it is inferred that, as the curvature of water lens increases, solar irradiance can be focused more accurately on to the focus and a higher water temperature is obtained inside the solar still.

  7. Modeled ground water age distributions

    Science.gov (United States)

    Woolfenden, Linda R.; Ginn, Timothy R.

    2009-01-01

    The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

  8. 3D electron density distributions in the solar corona during solar minima: assessment for more realistic solar wind modeling

    CERN Document Server

    de Patoul, Judith; Riley, Pete

    2015-01-01

    Knowledge of the electron density distribution in the solar corona put constraints on the magnetic field configurations for coronal modeling and on initial conditions for solar wind modeling. We work with polarized SOHO/LASCO-C2 images from the last two recent minima of solar activity (1996-1997 and 2008-2010), devoid of coronal mass ejections. The goals are to derive the 4D electron density distributions in the corona by applying a newly developed time-dependent tomographic reconstruction method and to compare the results between the two solar minima and with two magnetohydrodynamic models. First, we confirm that the values of the density distribution in thermodynamic models are more realistic than in polytropic ones. The tomography provides more accurate distributions in the polar regions, and we find that the density in tomographic and thermodynamic solutions varies with the solar cycle in both polar and equatorial regions. Second, we find that the highest-density structures do not always correspond to the...

  9. Mathematical modelling of unglazed solar collectors under extreme operating conditions

    DEFF Research Database (Denmark)

    Bunea, M.; Perers, Bengt; Eicher, S.

    2015-01-01

    average temperature levels at the evaporator. Simulation of these systems requires a collector model that can take into account operation at very low temperatures (below freezing) and under various weather conditions, particularly operation without solar irradiation.A solar collector mathematical model......Combined heat pumps and solar collectors got a renewed interest on the heating system market worldwide. Connected to the heat pump evaporator, unglazed solar collectors can considerably increase their efficiency, but they also raise the coefficient of performance of the heat pump with higher...... was found due to the condensation phenomenon and up to 40% due to frost under no solar irradiation. This work also points out the influence of the operating conditions on the collector's characteristics.Based on experiments carried out at a test facility, every heat flux on the absorber was separately...

  10. Comparative Study of MHD Modeling of the Background Solar Wind

    CERN Document Server

    Gressl, C; Temmer, M; Odstrcil, D; Linker, J A; Mikic, Z; Riley, P

    2013-01-01

    Knowledge about the background solar wind plays a crucial role in the framework of space weather forecasting. In-situ measurements of the background solar wind are only available for a few points in the heliosphere where spacecraft are located, therefore we have to rely on heliospheric models to derive the distribution of solar wind parameters in interplanetary space. We test the performance of different solar wind models, namely Magnetohydrodynamic Algorithm outside a Sphere/ENLIL (MAS/ENLIL), Wang-Sheeley-Arge/ENLIL (WSA/ENLIL), and MAS/MAS, by comparing model results with in-situ measurements from spacecraft located at 1 AU distance to the Sun (ACE, Wind). To exclude the influence of interplanetary coronal mass ejections (ICMEs), we chose the year 2007 as a time period with low solar activity for our comparison. We found that the general structure of the background solar wind is well reproduced by all models. The best model results were obtained for the parameter solar wind speed. However, the predicted ar...

  11. Simulation and modeling of solar radiation in Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Zuhairy, A.A.; Sayigh, A.A.M. [Reading Univ. (United Kingdom). Dept. of Engineering

    1995-04-01

    A mathematical model is used to generate the hourly data for the total solar radiation on a horizontal surface. The generated data are based on the hourly recorded visibility data for 20 years (1970-1989). The model year technique was then applied to model the 20 years of hourly data of solar radiation into one statistically representative year. A model year of hourly data was then generated for the beam and diffuse components of solar radiation on a horizontal surface. Similarly, a model year of hourly data was also generated for the total solar radiation on tilted surfaces with different orientations with its beam, diffuse and reflected components. A simple methodology is proposed for calculating the solar radiation on vertical surfaces, based on a solar impact factor (SIF). Monthly means and daily totals of hourly sums for each month of the year are discussed. The hourly data of solar radiation for a typical day for each month of the year are presented. The data were generated for the four climatic zones of Saudi Arabia, the hot-dry (Riyadh), the warm-humid (Jeddah), the maritime inland desert climate (Dhahran) and the upland climate zone (Taif). The accuracy of the results is discussed and found to be above 90% representative. (author)

  12. Storm Water Management Model (SWMM)

    Science.gov (United States)

    EPA's Storm Water Management Model (SWMM) is used throughout the world for planning, analysis and design related to stormwater runoff, combined and sanitary sewers, and other drainage systems in urban areas.

  13. Modelling Ballast Water Transport

    Digital Repository Service at National Institute of Oceanography (India)

    Jayakumar, S.; Babu, M.T.; Vethamony, P.

    by toolbox, available in MIKE software, by predicting the water elevation using the four major constituents M2, S2, K1 and O1 at the coastal tidal stations Okha and Godia (International Hydrographic Bureau, Spec. Pub, Monaco). Subsequently the tidal...-gulf is the highest compared to that on the northern and southern coasts. References Panvelkar, J.S., Bendre, V.M. and A.S.Barve (1986). ?Software for harmonic and spectral analysis of tidal data?, Proc. 3rd Indian Conference on ocean engineering, IIT Bombay, Dec...

  14. Natural convection heat exchangers for solar water heating systems. Technical progress report, September 15, 1996--November 14, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J.H.

    1998-06-01

    The goals of this project are: (1) to develop guidelines for the design and use of thermosyphon side-arm heat exchangers in solar domestic water heating systems, and (2) to establish appropriate modeling and testing criteria for evaluating the performance of systems using this type of heat exchanger. The tasks for the project are as follows: (1) Develop a model of the thermal performance of thermosyphon heat exchangers in solar water heating applications. A test protocol will be developed which minimizes the number of tests required to adequately account for mixed convection effects. The TRNSYS component model will be fully integrated in a system component model and will use data acquired with the specified test protocol. (2) Conduct a fundamental study to establish friction and heat transfer correlations for conditions and geometries typical of thermosyphon heat exchangers in solar systems. Data will be obtained as a function of a buoyancy parameter based on Grashof and Reynolds numbers. The experimental domain will encompass the ranges expected in solar water heating systems.

  15. Heat exchanger modelling in central receiver solar power plant using dense particle suspension

    Science.gov (United States)

    Reyes-Belmonte, Miguel A.; Gómez-García, Fabrisio; González-Aguilar, José; Romero, Manuel; Benoit, Hadrien; Flamant, Gilles

    2017-06-01

    In this paper, a detailed thermodynamic model for a heat exchanger (HX) working with a dense particle suspension (DPS) as heat transfer fluid (HTF) in the solar loop and water-steam as working fluid is presented. HX modelling is based on fluidized bed (FB) technology and its design has been conceived to couple solar plant using DPS as HTF and storage media with Rankine cycle for power generation. Using DPS as heat transfer fluid allows extending operating temperature range what will help to reduce thermal energy storage costs favoring higher energy densities but will also allow running power cycle at higher temperature what will increase its efficiency. Besides HX modelling description, this model will be used to reproduce solar plant performance under steady state and transient conditions.

  16. Elimination of disinfection byproduct formation potential in reclaimed water during solar light irradiation.

    Science.gov (United States)

    Qian-Yuan, Wu; Chao, Li; Ye, Du; Wen-Long, Wang; Huang, Huang; Hong-Ying, Hu

    2016-05-15

    Ecological storage of reclaimed water in ponds and lakes is widely applied in water reuse. During reclaimed water storage, solar light can degrade pollutants and improve water quality. This study investigated the effects of solar light irradiation on the disinfection byproduct formation potential in reclaimed water, including haloacetonitriles (HANs), trichloronitromethane (TCNM), trihalomethanes (THMs), haloketones (HKs) and chloral hydrate (CH). Natural solar light significantly decreased the formation potential of HANs, TCNM, and HKs in reclaimed water, but had a limited effect on the formation potential of THMs and CH. Ultraviolet (UV) light in solar radiation played a dominant role in the decrease of the formation potential of HANs, TCNM and HKs. Among the disinfection byproducts, the removal kinetic constant of dichloroacetonitrile (DCAN) with irradiation dose was much larger than those for dichloropropanone (1,1-DCP), trichloropropanone (1,1,1-TCP) and TCNM. During solar irradiation, fluorescence spectra intensities of reclaimed water also decreased significantly. The removal of tyrosine (Tyr)-like and tryptophan (Trp)-like protein fluorescence spectra intensity volumes was correlated to the decrease in DCAN formation potential. Solar irradiation was demonstrated to degrade Trp, Tyr and their DCAN formation potential. The photolysis products of Trp after solar irradiation were detected as kynurenine and tryptamine, which had chloroform, CH and DCAN formation potential lower than those of Trp.

  17. Experimental Study on Performance of a Box Solar Cooker with Flat Plate Collector to Boil Water

    Science.gov (United States)

    Sitepu, T.; Gunawan, S.; Nasution, D. M.; Ambarita, H.; Siregar, R. E. T.; Ronowikarto, A. D.

    2017-03-01

    In this study, a flat plate type solar cooker is tested by exposing in solar irradiation. The objective is to examine the performance of solar cooker in boiling water. The solar cooker is a box type with collector area and height are 100 × 100 cm and 40 cm, respectively. Vessel for water is made of aluminum plate with diameter and height of 22 cm and 15 cm. The experiments are performed by varying mass of the water. It is 2 kg and 4 kg, respectively. Every experiment starts from 10:00 AM until the boiling temperature is reached. The parameters measured are radiance intensity, ambient and solar box cooker temperatures, and wind speed. The results show that the duration of water heating up to 100°C with water mass 2 kg within 2 hours 45 minutes and water mass 4 kg within 3 hours 17 minutes. The maximum temperatur of solar box cooker is 117°C at 12:56 PM and maximum efficiency is 46.30%. The main conclusion can be drawn here is that a simple solar box cooker can be used to boil water.

  18. Kinematic solar dynamo models with a deep meridional flow

    Science.gov (United States)

    Guerrero, G. A.; Muñoz, J. D.

    2004-05-01

    We develop two different solar dynamo models to verify the hypothesis that a deep meridional flow can restrict the appearance of sunspots below 45°, proposed recently by Nandy & Choudhuri. In the first one, a single polytropic approximation for the density profile was taken, for both radiative and convective zones. In the second one, that of Pinzon & Calvo-Mozo, two polytropes were used to distinguish between both zones. The magnetic buoyancy mechanism proposed by Dikpati & Charbonneau was chosen in both models. We have in fact obtained that a deep meridional flow pushes the maxima of toroidal magnetic field towards the solar equator, but, in contrast to Nandy & Choudhuri, a second zone of maximal fields remains at the poles. The second model, although closely resembling the solar standard model of Bahcall et al., gives solar cycles three times longer than observed.

  19. Kinematic solar dynamo models with a deep meridional flow

    CERN Document Server

    Guerrero, G A

    2004-01-01

    We develop two different solar dynamo models to verify the hypothesis that a deep meridional flow can restrict the apperance of sunspots below 45 degrees, proposed by Nandy & Choudhuri (2002). In the first one, a single polytropic approximation for the density profile was taken, for both radiative and convective zones. In the second one, two polytropes were used to distinguish between both zones Pinzon & Calvo-Mozo (2001). The magnetic buoyancy mechanism proposed by Dikpati & Charbonneau (1999) was chosen in both models. We, actually, have obtained that a deep meridional flow pushes the maxima of toroidal magnetic field toward the solar equator, but in contrast to Nandy & Choudhuri (2002) a second zone of maximal fields remains at the poles. The second model, although closely resembling the solar standard model of Bahcall, Pinsonneault & Wasserbug (1995); Bahcall, Pinsonneault & Basu (2001), gives solar cyles three times longer than observed.

  20. Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

    Directory of Open Access Journals (Sweden)

    Thomas Semenou

    2015-01-01

    Full Text Available Nowadays, in several types of commercial or institutional buildings, a significant rise of transpired solar collectors used to preheat the fresh air of the building can be observed. Nevertheless, when the air mass flow rate is low, the collector efficiency collapses and a large amount of energy remains unused. This paper presents a simple yet effective mathematical model of a transparent transpired solar collector (TTC with dual intake in order to remove stagnation problems in the plenum and ensure a better thermal efficiency and more heat recovery. A thermal model and a pressure loss model were developed. Then, the combined model was validated with experimental data from the Solar Rating and Certification Corporation (SRCC. The results show that the collector efficiency can be up to 70% and even 80% regardless of operating conditions. The temperature gain is able to reach 20°K when the solar irradiation is high.

  1. Dimensioning of a solar water heater made from PET bottles; Dimensionamento de um aquecedor solar de agua feito com garrafas PET

    Energy Technology Data Exchange (ETDEWEB)

    Bertoleti, Pedro Henrique Fonseca; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis

    2008-07-01

    This document show the solar water heater made of PET bottles, a simple-construction solar water heater that try to give us two important solutions, water heating using solar energy and reutilization of the PET bottles left in the nature. Also, it will be showed how to do the dimensioning of it. Based on the showed dimensioning a application / software is developed and after that simulations are made using the application to provide how is the economy if it's used this kind of solar water heater and their environmental contribution by reutilization of the PET bottles abandoned in the nature. For example, in a common home the economy is about 45% of the electricity bill considering that the warmed water is used just to take a shower. So, the conclusion is: the solar water heater made by PET bottles is a very relevant equipment to the use of the solar energy, to useful applications and environmental contribution. (author)

  2. Modeling the heliospheric current sheet: Solar cycle variations

    Science.gov (United States)

    Riley, Pete; Linker, J. A.; Mikić, Z.

    2002-07-01

    In this report we employ an empirically driven, three-dimensional MHD model to explore the evolution of the heliospheric current sheet (HCS) during the course of the solar cycle. We compare our results with a simpler ``constant-speed'' approach for mapping the HCS outward into the solar wind to demonstrate that dynamic effects can substantially deform the HCS in the inner heliosphere (ballerina skirt,'' we discuss an interval approaching the maximum of solar cycle 23 (Carrington rotations 1960 and 1961) when the shape would be better described as ``conch shell''-like. We use Ulysses magnetic field measurements to support the model results.

  3. Modeling Jets in the Corona and Solar Wind

    CERN Document Server

    Torok, T; Titov, V S; Leake, J E; Mikic, Z; Linker, J A; Linton, M G

    2015-01-01

    Coronal jets are transient, collimated eruptions that occur in regions of predominantly open magnetic field in the solar corona. Our understanding of these events has greatly evolved in recent years but several open questions, such as the contribution of coronal jets to the solar wind, remain. Here we present an overview of the observations and numerical modeling of coronal jets, followed by a brief description of "next-generation" simulations that include an advanced description of the energy transfer in the corona ("thermodynamic MHD"), large spherical computational domains, and the solar wind. These new models will allow us to address some of the open questions.

  4. A Smoothed Eclipse Model for Solar Electric Propulsion Trajectory Optimization

    Science.gov (United States)

    Aziz, Jonathan; Scheeres, Daniel; Parker, Jeffrey; Englander, Jacob

    2017-01-01

    Solar electric propulsion (SEP) is the dominant design option for employing low-thrust propulsion on a space mission. Spacecraft solar arrays power the SEP system but are subject to blackout periods during solar eclipse conditions. Discontinuity in power available to the spacecraft must be accounted for in trajectory optimization, but gradient-based methods require a differentiable power model. This work presents a power model that smooths the eclipse transition from total eclipse to total sunlight with a logistic function. Example trajectories are computed with differential dynamic programming, a second-order gradient-based method.

  5. A dissipative model of solar system

    Science.gov (United States)

    Vladimir, V. G.

    2009-04-01

    In classical model of Solar system of a planet are represented by the material points cooperating under the law of universal gravitation. This model remains fair if planet to consider as absolutely firm spheres with spherical distribution of density. The gravitational potential of such body coincides with potential of a material point, and rotation of each sphere concerning his centre of weights occurs to constant angular speed. Movement concerning the centre of weights of a sphere is represented by rotation with constant angular speed concerning an axis of an any direction, and movement of the centers of weights of spherical planets identically to movement in the appropriate problem of N points. Let's notice, that forms of planets of Solar system are close to spherical as dominant forces at formation of planets are gravitational forces to which forces of molecular interaction in substance of a planet counteract. The model of the isolated Solar system submitted in a not indignant condition N by homogeneous viscoelastic spheres is considered. Under action of own rotation and tidal gravitational forces the spherical planet changes the form: there is "flattening" a planet in a direction of a vector of its angular speed and formation of tidal humps on the lines connecting the centre of a planet with the centers of other planets. From a variational principle of Hamilton the full system of the equations describing movements of the centers of weights of planets, rotations of systems of coordinates, by integrated image connected with planets, and deformations of planets be relative these of systems of coordinates is received. It is supposed, that tidal gravitational, centrifugal and elastic forces result in small change of the spherical form of a planet. In system there are small parameters - inversely proportional of the Young modules of materials of the planets, providing small deformations of planets at influence on them of the centrifugal forces produced by own

  6. Performance enhancement of modified solar still using water sprinkler: An experimental approach

    Directory of Open Access Journals (Sweden)

    Bhupendra Gupta

    2016-09-01

    Full Text Available In this communication, existing design of single slope solar still has been modified, developed and tested. The modifications in conventional single slope solar still include (i inside walls painted with white colour and (ii attachment of water sprinkler with constant water flow rate of 0.0001 kg/s on the glass cover. The performance of modified single slope solar still has been evaluated and compared with conventional solar still. Experiments have been carried out on both modified and conventional single slope solar still for 05 cm water depth in the month of April at Jabalpur (Latitude 23°18′ N; Longitude 79°95′ E India. The distilled water output was recorded 2940 ml and 3541 ml from conventional and modified solar stills respectively. Water productivity or yield of single slope solar still is increased by 20% from above modifications. The overall efficiency is increased by 21% over the conventional solar still.

  7. Design, Fabrication, and Efficiency Study of a Novel Solar Thermal Water Heating System: Towards Sustainable Development

    Directory of Open Access Journals (Sweden)

    M. Z. H. Khan

    2016-01-01

    Full Text Available This paper investigated a novel loop-heat-pipe based solar thermal heat-pump system for small scale hot water production for household purposes. The effective use of solar energy is hindered by the intermittent nature of its availability, limiting its use and effectiveness in domestic and industrial applications especially in water heating. The easiest and the most used method is the conversion of solar energy into thermal energy. We developed a prototype solar water heating system for experimental test. We reported the investigation of solar thermal conversion efficiency in different seasons which is 29.24% in summer, 14.75% in winter, and 15.53% in rainy season. This paper also discusses the DC heater for backup system and the current by using thermoelectric generator which are 3.20 V in summer, 2.120 V in winter, and 1.843 V in rainy season. This solar water heating system is mostly suited for its ease of operation and simple maintenance. It is expected that such novel solar thermal technology would further contribute to the development of the renewable energy (solar driven heating/hot water service and therefore lead to significant environmental benefits.

  8. Combined photovoltaic/thermal solar array dc electrical model

    Energy Technology Data Exchange (ETDEWEB)

    Krikorian, J.S. Jr.

    1981-12-01

    An electrical model of a combined photovoltaic/thermal solar array has been developed to predict the steady state behavior of the line currents, power output and array voltage. The effects of temperature on the solar cell characteristics is included in the analysis. The model includes line isolation diodes and ''open cell'' bypass diodes. A numerical procedure based on the Contraction Mapping Fixed Point Theorem is used to solve the associated nonlinear equations. 6 refs.

  9. Availability modeling methodology applied to solar power systems

    Science.gov (United States)

    Unione, A.; Burns, E.; Husseiny, A.

    1981-01-01

    Availability is discussed as a measure for estimating the expected performance for solar- and wind-powered generation systems and for identifying causes of performance loss. Applicable analysis techniques, ranging from simple system models to probabilistic fault tree analysis, are reviewed. A methodology incorporating typical availability models is developed for estimating reliable plant capacity. Examples illustrating the impact of design and configurational differences on the expected capacity of a solar-thermal power plant with a fossil-fired backup unit are given.

  10. Solar hot water system installed at Day's Inn Motel, Dallas, Texas (Valley View)

    Science.gov (United States)

    1980-09-01

    The solar system was designed to provide 65 percent of the total domestic hot water (DHW) demand. A liquid (water) flat plate collector (1,000 square feet) system automatically drains into the 1,000 gallon steel storage tank when the solar pump is not running. Heat is transferred from the DHW tanks through a shell and tube heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up standby losses. All pumps are controlled by differential temperature controllers.

  11. To the Problem of Designing Water Heating Solar Systems with Flat Collectors for Individual Dwellings

    Directory of Open Access Journals (Sweden)

    B. M. Khroustalev

    2011-01-01

    Full Text Available The variant of efficient combination of two renewable energy sources as a biogas system and a water heating solar system has been considered for power supply of individual dwellings. Criteria dependence has been suggested for determination of solar system power efficiency. Its legitimacy has been proved by an experiment. Power efficient solar system has been proposed with peculiar features of its designing and due account of energy flow distribution in technology of biogas production.

  12. Cost Effective System Modeling of Active Micro- Module Solar Tracker

    Directory of Open Access Journals (Sweden)

    Md. Faisal Shuvo

    2014-01-01

    Full Text Available The increasing interests in using renewable energies are coming from solar thermal energy and solar photovoltaic systems to the micro production of electricity. Usually we already have considered the solar tracking topology in large scale applications like power plants and satellite but most of small scale applications don’t have any solar tracker system, mainly because of its high cost and complex circuit design. From that aspect, this paper confab microcontroller based one dimensional active micro-module solar tracking system, in which inexpensive LDR is used to generate reference voltage to operate microcontroller for functioning the tracking system. This system provides a fast response of tracking system to the parameters like change of light intensity as well as temperature variations. This micro-module model of tracking system can be used for small scale applications like portable electronic devices and running vehicles.

  13. Solar Spectral Irradiance under Clear and Cloudy Skies: Measurements and a Semiempirical Model.

    Science.gov (United States)

    Nann, Stefan; Riordan, Carol

    1991-04-01

    In a combined effort, the Centre for Solar Energy and Hydrogen Research in Germany and the Solar Energy Research Institute in the United States analyzed several thousand measurements of the solar spectral irradiance recorded at four sites. The goal was to develop a semiempirical model that describes the total solar spectral irradiance for clear and cloudy sky conditions based on readily available input data.To investigate how the spectral transmission of clouds deviates from an assumed neutral density filter, the measured spectra are compared with simulated clear-sky spectra. A correlation is established between the cloud thickness and the relatively higher transmission of clouds in the ultraviolet and blue region of the solar spectrum. Using this approach, a semiempirical model is proposed based solely on global and diffuse broadband irradiance measurements, precipitable water-vapor data, and the sun's position. The model, called SEDESI, is applied to calculate spectral irradiance in short time steps (30 or 60 minutes) that are needed for either the design and performance analysis of spectrally selective solar energy conversion systems or to predict daylight availability. The results are also applicable to current climate research areas such as validating radiative transfer codes.

  14. The MSFC Solar Activity Future Estimation (MSAFE) Model

    Science.gov (United States)

    Suggs, Ron

    2017-01-01

    The Natural Environments Branch of the Engineering Directorate at Marshall Space Flight Center (MSFC) provides solar cycle forecasts for NASA space flight programs and the aerospace community. These forecasts provide future statistical estimates of sunspot number, solar radio 10.7 cm flux (F10.7), and the geomagnetic planetary index, Ap, for input to various space environment models. For example, many thermosphere density computer models used in spacecraft operations, orbital lifetime analysis, and the planning of future spacecraft missions require as inputs the F10.7 and Ap. The solar forecast is updated each month by executing MSAFE using historical and the latest month's observed solar indices to provide estimates for the balance of the current solar cycle. The forecasted solar indices represent the 13-month smoothed values consisting of a best estimate value stated as a 50 percentile value along with approximate +/- 2 sigma values stated as 95 and 5 percentile statistical values. This presentation will give an overview of the MSAFE model and the forecast for the current solar cycle.

  15. Solar energy water desalination in the United States and Saudi Arabia

    Science.gov (United States)

    Luft, W.; William, J.

    1981-01-01

    Five solar energy water desalination systems were designed to deliver 6000 cubic m/day of desalted water from either seawater or brackish water. Two systems will be selected for pilot plant construction. The pilot plants will have capacities in the range of 100 to 400 m/day. Goals of the Project Agreement for Cooperation in the Field of Solar Energy, under the auspices of the United States-Saudi Arabian Joint Commission on Economic Cooperation, are to: (1) cooperate in the field of solar energy technology for the mutual benefit of the two countries, including the development and stimulation of solar industries within the two countries; (2) advance the development of solar energy technology in the two countries; and (3) facilitate the transfer between the two countries of technology developed under this agreement.

  16. Field Surveys of Non-Residential Solar Water Heating Systems in Taiwan

    Directory of Open Access Journals (Sweden)

    Kung-Ming Chung

    2012-02-01

    Full Text Available To develop indigenous alternative and renewable energy resources, long-term subsidy programs (1986–1991 and 2000–present for solar water heaters have been enforced in Taiwan. By the end of 2010, the total installed area of solar collectors had exceeded 2 million square meters. However, over 98% of solar water heaters were used in residential systems for hot water production, with the areas of installed solar collector being less than 10 square meters. There were only 98 systems with area of solar collectors installed exceeding 100 square meters put into operation from 2001 to 2010. These systems were mainly installed for water heating in dormitories, swimming pools, restaurants, and manufacturing plants. In the present study, a comprehensive survey of these large-scale solar water heaters was conducted. The objectives of the survey were to assess the system performance and to collect feedback from individual users. It is found that lack of experience in system design and maintenance are the key factors affecting reliable operation of a system. Hourly, daily and long-term field measurements of a dormitory system were also examined to evaluate its thermal efficiencies. Results indicated that thermal efficiency of the system is associated with the daily solar radiation. Hot water use pattern and operation of auxiliary heater should be taken into account in system design.

  17. The Utilisation of Solar System in Combined Heating System of Water

    Directory of Open Access Journals (Sweden)

    Ján Jobbágy

    2017-01-01

    Full Text Available The paper assessed the topicality and returns of solar system utilization to heating of water. Practical measurements were conducted after reconstruction of the family house. (in Nesvady, Slovak republic, on which the solar system were assembled. The system consists of the gas heater, solar panels, distributions and circulation pump. The solar system was assembled due to decreasing of operation costs and connected with conventional already used gas heating system by boiler Quantum (V = 115 L. The conventional system was used for 21 days to gather basic values for evaluation. At this point it was observed that 11.93 m3 of gas is needed to heat up 1 m3 of water. Used water in this case was heated from initial 16.14 °C to 52.04 °C of output temperature. Stand by regime of boiler was characterized by 0.012 m3.h-1 consumption of gas. The rest of the measurements represent the annual (from 03/2013 to 02/2014 operation process of boiler Tatramat VTS 200L (trivalent with 200 litres of volume (as a part of Thermosolar solar system. The solar collectors TS 300 are also part of the solar system. An input and output temperatures of heating water we observed along with water and gas consumption, intensity of solar radiation and actual weather conditions. The amount of heat produced by solar system was then calculated. Total investment on solar system were 2,187.7 € (1,475.7 € with subsidy. Therefore, return on investment for the construction of the solar system was set at 23 years even with subsidy.

  18. Early solar system. Early accretion of water in the inner solar system from a carbonaceous chondrite-like source.

    Science.gov (United States)

    Sarafian, Adam R; Nielsen, Sune G; Marschall, Horst R; McCubbin, Francis M; Monteleone, Brian D

    2014-10-31

    Determining the origin of water and the timing of its accretion within the inner solar system is important for understanding the dynamics of planet formation. The timing of water accretion to the inner solar system also has implications for how and when life emerged on Earth. We report in situ measurements of the hydrogen isotopic composition of the mineral apatite in eucrite meteorites, whose parent body is the main-belt asteroid 4 Vesta. These measurements sample one of the oldest hydrogen reservoirs in the solar system and show that Vesta contains the same hydrogen isotopic composition as that of carbonaceous chondrites. Taking into account the old ages of eucrite meteorites and their similarity to Earth's isotopic ratios of hydrogen, carbon, and nitrogen, we demonstrate that these volatiles could have been added early to Earth, rather than gained during a late accretion event.

  19. Near Earth Asteroid Scout Solar Sail Thrust and Torque Model

    Science.gov (United States)

    Heaton, Andy; Ahmad, Naeem; Miller, Kyle

    2017-01-01

    The Near Earth Asteroid (NEA) Scout is a solar sail mission whose objective is to scout at least one Near Earth Asteroid to help prepare for human missions to Near Earth Asteroids. NEA Scout will launch as a secondary payload on the first SLS-Orion mission. NEA Scout will perform a small trim maneuver shortly after deploy from the spent SLS upper stage using a cold gas propulsion system, but from that point on will depend entirely on the solar sail for thrust. As such, it is important to accurately characterize the thrust of the sail in order to achieve mission success. Additionally, the solar sail creates a relatively large solar disturbance torque that must be mitigated. For early mission design studies a flat plate model of the solar sail with a fixed center of pressure was adequate, but as mission concepts and the sail design matured, greater fidelity was required. Here we discuss the progress to a three-dimensional sail model that includes the effects of tension and thermal deformation that has been derived from a large structural Finite Element Model (FEM) developed by the Langley Research Center. We have found that the deformed sail membrane affects torque relatively much more than thrust; a flat plate model could potentially model thrust well enough to close mission design studies, but a three-dimensional solar sail is essential to control system design. The three-dimensional solar sail model revealed that thermal deformations of unshielded booms would create unacceptably large solar disturbance torques. The original large FEM model was used in control and mission simulations, but was resulted in simulations with prohibitive run times. This led us to adapt the Generalized Sail Model (GSM) of Rios-Reyes. A design reference sail model has been baselined for NEA Scout and has been used to design the mission and control system for the sailcraft. Additionally, since NEA Scout uses reaction wheels for attitude pointing and control, the solar torque model is

  20. A Systematic Evaluation Model for Solar Cell Technologies

    Directory of Open Access Journals (Sweden)

    Chang-Fu Hsu

    2014-01-01

    Full Text Available Fossil fuels, including coal, petroleum, natural gas, and nuclear energy, are the primary electricity sources currently. However, with depletion of fossil fuels, global warming, nuclear crisis, and increasing environmental consciousness, the demand for renewable energy resources has skyrocketed. Solar energy is one of the most popular renewable energy resources for meeting global energy demands. Even though there are abundant studies on various solar technology developments, there is a lack of studies on solar technology evaluation and selection. Therefore, this research develops a model using interpretive structural modeling (ISM, benefits, opportunities, costs, and risks concept (BOCR, and fuzzy analytic network process (FANP to aggregate experts' opinions in evaluating current available solar cell technology. A case study in a photovoltaics (PV firm is used to examine the practicality of the proposed model in selecting the most suitable technology for the firm in manufacturing new products.

  1. River water quality modelling: II

    DEFF Research Database (Denmark)

    Shanahan, P.; Henze, Mogens; Koncsos, L.

    1998-01-01

    The U.S. EPA QUAL2E model is currently the standard for river water quality modelling. While QUAL2E is adequate for the regulatory situation for which it was developed (the U.S. wasteload allocation process), there is a need for a more comprehensive framework for research and teaching. Moreover......, and to achieve robust model calibration. Mass balance problems arise from failure to account for mass in the sediment as well as in the water column and due to the fundamental imprecision of BOD as a state variable. (C) 1998 IAWQ Published by Elsevier Science Ltd. All rights reserved....

  2. Chemo-dynamical deuterium fractionation in the early solar nebula: The origin of water on Earth and in asteroids and comets

    CERN Document Server

    Albertsson, T; Henning, Th

    2014-01-01

    Formation and evolution of water in the Solar System and the origin of water on Earth constitute one of the most interesting questions in astronomy. The prevailing hypothesis for the origin of water on Earth is by delivery through water-rich small Solar system bodies. In this paper, the isotopic and chemical evolution of water during the early history of the solar nebula, before the onset of planetesimal formation, is studied. A gas-grain chemical model that includes multiply-deuterated species and nuclear spin-states is combined with a steady-state solar nebula model. To calculate initial abundances, we simulated 1 Myr of evolution of a cold and dark TMC1-like prestellar core. Two time-dependent chemical models of the solar nebula are calculated over 1 Myr: (1) a laminar model and (2) a model with 2D turbulent mixing. We find that the radial outward increase of the H2O D/H ratio is shallower in the chemo-dynamical nebular model compared to the laminar model. This is related to more efficient de-fractionation...

  3. Hawaii Solar Integration Study: Solar Modeling Developments and Study Results; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Orwig, K.; Corbus, D.; Piwko, R.; Schuerger, M.; Matsuura, M.; Roose, L.

    2012-12-01

    The Hawaii Solar Integration Study (HSIS) is a follow-up to the Oahu Wind Integration and Transmission Study completed in 2010. HSIS focuses on the impacts of higher penetrations of solar energy on the electrical grid and on other generation. HSIS goes beyond the island of Oahu and investigates Maui as well. The study examines reserve strategies, impacts on thermal unit commitment and dispatch, utilization of energy storage, renewable energy curtailment, and other aspects of grid reliability and operation. For the study, high-frequency (2-second) solar power profiles were generated using a new combined Numerical Weather Prediction model/ stochastic-kinematic cloud model approach, which represents the 'sharp-edge' effects of clouds passing over solar facilities. As part of the validation process, the solar data was evaluated using a variety of analysis techniques including wavelets, power spectral densities, ramp distributions, extreme values, and cross correlations. This paper provides an overview of the study objectives, results of the solar profile validation, and study results.

  4. Modeling Polarized Solar Radiation for Correction of Satellite Data

    Science.gov (United States)

    Sun, W.

    2014-12-01

    Reflected solar radiation from the Earth-atmosphere system is polarized. If a non-polarimetric sensor has some polarization dependence, it can result in errors in the measured radiance. To correct the polarization-caused errors in satellite data, the polarization state of the reflected solar light must be known. In this presentation, recent studies of the polarized solar radiation from the ocean-atmosphere system with the adding-doubling radiative-transfer model (ADRTM) are reported. The modeled polarized solar radiation quantities are compared with PARASOL satellite measurements and DISORT model results. Sensitivities of reflected solar radiation's polarization to various ocean-surface and atmospheric conditions are addressed. A novel super-thin cloud detection method based on polarization measurements is also discussed. This study demonstrates that the modeling can provide a reliable approach for making the spectral Polarization Distribution Models (PDMs) for satellite inter-calibration applications of NASA's future Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission. Key words: Reflected solar radiation, polarization, correction of satellite data.

  5. A Model for Hourly Solar Radiation Data Generation from Daily Solar Radiation Data Using a Generalized Regression Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Tamer Khatib

    2015-01-01

    Full Text Available This paper presents a model for predicting hourly solar radiation data using daily solar radiation averages. The proposed model is a generalized regression artificial neural network. This model has three inputs, namely, mean daily solar radiation, hour angle, and sunset hour angle. The output layer has one node which is mean hourly solar radiation. The training and development of the proposed model are done using MATLAB and 43800 records of hourly global solar radiation. The results show that the proposed model has better prediction accuracy compared to some empirical and statistical models. Two error statistics are used in this research to evaluate the proposed model, namely, mean absolute percentage error and root mean square error. These values for the proposed model are 11.8% and −3.1%, respectively. Finally, the proposed model shows better ability in overcoming the sophistic nature of the solar radiation data.

  6. Solar heating and domestic hot water system installed at North Dallas High School

    Science.gov (United States)

    1980-01-01

    The solar energy system located at the North Dallas High School, Dallas, Texas is discussed. The system is designed as a retrofit in a three story with basement, concrete frame high school building. Extracts from the site files, specification references for solar modification to existing building heating and domestic hot water systems, drawings, installation, operation and maintenance instructions are included.

  7. Analysis of off-grid hybrid wind turbine/solar PV water pumping systems

    Science.gov (United States)

    While many remote water pumping systems exist (e.g. mechanical windmills, solar photovoltaic , wind-electric, diesel powered), very few combine both the wind and solar energy resources to possibly improve the reliability and the performance of the system. In this paper, off-grid wind turbine (WT) a...

  8. Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application

    Directory of Open Access Journals (Sweden)

    Hrushikesh Bhujangrao Kulkarni

    2016-02-01

    Full Text Available Concentrating collectors absorbs solar energy and convert it into heat for generating hot water, steam at required temperature, which can be further used for solar thermal applications. The developing countries like India where solar energy is abundantly available; there is need to develop technology for harnessing solar energy for power production, but the main problem associated with concentrating solar power technology is the high cost of installation and low output efficiency. To solve this problem, a prototype cylindrical parabolic solar collector having aperture area of 1.89 m2 is designed and developed using low cost highly reflecting and absorbing material to reduce initial cost of project and improve thermal efficiency. ASHRAE Standard 93, 1986 was used to evaluate the thermal performance and it was observed that this system can generate hot water at an average temperature of 500C per day with an average efficiency of 49% which is considerable higher than flat plate solar collectors. Hot water produced by this system can be useful for domestic, agricultural, industrial process heat applications.Article History: Received Sept 19, 2015; Received in revised form Dec 23, 2015; Accepted February 2, 2016; Available online How to Cite This Article: Bhujangrao, K.H. (2016. Design and Development of Prototype Cylindrical Parabolic Solar Collector for Water Heating Application. International Journal of Renewable Energy Development, 5(1, 49-55 http://dx.doi.org/10.14710/ijred.5.1.49-55 

  9. Solar optical codes evaluation for modeling and analyzing complex solar receiver geometries

    Science.gov (United States)

    Yellowhair, Julius; Ortega, Jesus D.; Christian, Joshua M.; Ho, Clifford K.

    2014-09-01

    Solar optical modeling tools are valuable for modeling and predicting the performance of solar technology systems. Four optical modeling tools were evaluated using the National Solar Thermal Test Facility heliostat field combined with flat plate receiver geometry as a benchmark. The four optical modeling tools evaluated were DELSOL, HELIOS, SolTrace, and Tonatiuh. All are available for free from their respective developers. DELSOL and HELIOS both use a convolution of the sunshape and optical errors for rapid calculation of the incident irradiance profiles on the receiver surfaces. SolTrace and Tonatiuh use ray-tracing methods to intersect the reflected solar rays with the receiver surfaces and construct irradiance profiles. We found the ray-tracing tools, although slower in computation speed, to be more flexible for modeling complex receiver geometries, whereas DELSOL and HELIOS were limited to standard receiver geometries such as flat plate, cylinder, and cavity receivers. We also list the strengths and deficiencies of the tools to show tool preference depending on the modeling and design needs. We provide an example of using SolTrace for modeling nonconventional receiver geometries. The goal is to transfer the irradiance profiles on the receiver surfaces calculated in an optical code to a computational fluid dynamics code such as ANSYS Fluent. This approach eliminates the need for using discrete ordinance or discrete radiation transfer models, which are computationally intensive, within the CFD code. The irradiance profiles on the receiver surfaces then allows for thermal and fluid analysis on the receiver.

  10. Estimating Water Footprints of Vegetable Crops: Influence of Growing Season, Solar Radiation Data and Functional Unit

    Directory of Open Access Journals (Sweden)

    Betsie le Roux

    2016-10-01

    Full Text Available Water footprint (WF accounting as proposed by the Water Footprint Network (WFN can potentially provide important information for water resource management, especially in water scarce countries relying on irrigation to help meet their food requirements. However, calculating accurate WFs of short-season vegetable crops such as carrots, cabbage, beetroot, broccoli and lettuce presented some challenges. Planting dates and inter-annual weather conditions impact WF results. Joining weather datasets of just rainfall, minimum and maximum temperature with ones that include solar radiation and wind-speed affected crop model estimates and WF results. The functional unit selected can also have a major impact on results. For example, WFs according to the WFN approach do not account for crop residues used for other purposes, like composting and animal feed. Using yields in dry matter rather than fresh mass also impacts WF metrics, making comparisons difficult. To overcome this, using the nutritional value of crops as a functional unit can connect water use more directly to potential benefits derived from different crops and allow more straightforward comparisons. Grey WFs based on nitrogen only disregards water pollution caused by phosphates, pesticides and salinization. Poor understanding of the fate of nitrogen complicates estimation of nitrogen loads into the aquifer.

  11. Comparison between a new TRNSYS model and experimental data of phase change materials in a solar combisystem

    Energy Technology Data Exchange (ETDEWEB)

    Bony, J.; Citherlet, S.

    2007-07-01

    In the framework of the IEA Task 32 (Solar Heating and Cooling Programme), we developed a numeric model to simulate heat transfer in phase change materials (PCM), and experimental data. The analyzed system is bulk PCM plunged in a water tank storage of a solar combisystem (heating and domestic hot water production). The numerical model, based on the enthalpy approach, takes into account hysteresis and subcooling characteristic and also the conduction and the convection in the PCM. This model has been implemented in an existing TRNSYS type of water tank storage. The simulations has been compared with experimental data obtained with a solar installation using water tank storage of about 900 litres, already studied during the IEA Task 26 (Weiss 2003). (author)

  12. Solar XUV and ENA-driven water loss from early Venus' steam atmosphere

    Science.gov (United States)

    Lichtenegger, H. I. M.; Kislyakova, K. G.; Odert, P.; Erkaev, N. V.; Lammer, H.; Gröller, H.; Johnstone, C. P.; Elkins-Tanton, L.; Tu, L.; Güdel, M.; Holmström, M.

    2016-05-01

    We present a study on the influence of the upper atmosphere hydrodynamic escape of hydrogen, driven by the solar soft X-ray and extreme ultraviolet radiation (XUV), on an expected outgassed steam atmosphere of early Venus. By assuming that the young Sun was either a weak or moderately active young G star, we estimated the water loss from a hydrogen dominated thermosphere due to the absorption of the solar XUV flux and the precipitation of solar wind produced energetic hydrogen atoms (ENAs). The production of ENAs and their interaction with the hydrodynamic extended upper atmosphere, including collision-related feedback processes, have been calculated by means of Monte Carlo models. ENAs that collide in the upper atmosphere deposit their energy and heat the surrounding atmosphere mainly above the main XUV energy deposition layer. It is shown that precipitating ENAs modify the thermal structure of the upper atmosphere, but the enhancement of the thermal escape rates caused by these energetic hydrogen atoms is negligible. Our results also indicate that the majority of oxygen arising from dissociated H2O molecules is left behind during the first 100 Myr. It is thus suggested that the main part of the remaining oxygen has been absorbed by crustal oxidation.

  13. Modeling water waves beyond perturbations

    CERN Document Server

    Clamond, Didier

    2015-01-01

    In this chapter, we illustrate the advantage of variational principles for modeling water waves from an elementary practical viewpoint. The method is based on a `relaxed' variational principle, i.e., on a Lagrangian involving as many variables as possible, and imposing some suitable subordinate constraints. This approach allows the construction of approximations without necessarily relying on a small parameter. This is illustrated via simple examples, namely the Serre equations in shallow water, a generalization of the Klein-Gordon equation in deep water and how to unify these equations in arbitrary depth. The chapter ends with a discussion and caution on how this approach should be used in practice.

  14. Improved Solar-Radiation-Pressure Models for GPS Satellites

    Science.gov (United States)

    Bar-Sever, Yoaz; Kuang, Da

    2006-01-01

    A report describes a series of computational models conceived as an improvement over prior models for determining effects of solar-radiation pressure on orbits of Global Positioning System (GPS) satellites. These models are based on fitting coefficients of Fourier functions of Sun-spacecraft- Earth angles to observed spacecraft orbital motions.

  15. Primitive Liquid Water of the Solar System in an Aqueous Altered Carbonaceous Chondrite

    Science.gov (United States)

    Tsuchiyama, A.; Miyake, A.; Kitayama, A.; Matsuno, J.; Takeuchi, A.; Uesugi, K.; Suzuki, Y.; Nakano, T.; Zolensky, M. E.

    2016-01-01

    Non-destructive 3D observations of the aqueous altered CM chondrite Sutter's Mill using scanning imaging x-ray microscopy (SIXM) showed that some of calcite and enstatite grains contain two-phase inclusion, which is most probably composed of liquid water and bubbles. This water should be primitive water responsible for aqueous alteration in an asteroid in the early solar system.

  16. Solar Energy Water Desalination in the United States and Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Luft, W.

    1981-04-01

    Five solar energy water desalination systems are described. The systems will each deliver 6000 m3/day of desalted water from either seawater or brackish water. After the system definition study is completed in August 1981, two systems will be selected for pilot plant construction. The pilot plants will have capacities in the range of 1 00 to 400 m3/day.

  17. Design package for a complete residential solar space heating and hot water system

    Science.gov (United States)

    1978-01-01

    Information necessary to evaluate the design of a solar space heating and hot water system is reported. System performance specifications, the design data brochure, the system description, and other information pertaining to the design are included.

  18. Study of the distribution of the absorbed solar radiation on the performance of a CPC-type ICS water heater

    Energy Technology Data Exchange (ETDEWEB)

    Souliotis, M.; Tripanagnostopoulos, Y. [Physics Department, University of Patras, 26504 Patras (Greece)

    2008-05-15

    An Integrated Collector Storage (ICS) solar water heater was designed, constructed and studied with an emphasis on its optical and thermal performance. The ICS system consists of one cylindrical horizontal tank properly mounted in a stationary symmetrical Compound Parabolic Concentrating (CPC) reflector trough. The main objective was the design and the construction of a low cost solar system with improved thermal performance based on the exploitation of the non-uniform distribution of the absorbed solar radiation on the cylindrical storage tank surface. A ray-tracing model was developed to gauge the distribution of the incoming solar radiation on the absorber surface and the results were compared with those from a theoretical optical model based on the average number of reflections. The variation of the optical efficiency as function of the incident angle of the incoming solar radiation along with its dependence on the month during annual operation of ICS system is presented. The ICS device was experimentally tested outdoors during a whole year in order to correlate the observed temperature rise and stratification of the stored water with the non-uniform distribution of the absorbed solar radiation. The results show that the upper part of the tank surface collects the larger fraction of the total absorbed solar radiation for all incident angles throughout the year. This is found to have a significant effect on the overall thermal performance of the ICS unit. In addition, the presented results can be considered important for the design and the operation of ICS systems consisting of cylindrical tank and CPC reflectors. (author)

  19. The Search for Surviving Direct Samples of Early Solar System Water

    Science.gov (United States)

    Zolensky, Michael

    2016-01-01

    We have become increasingly aware of the fundamental importance of water, and aqueous alteration, on primitive solar-system bodies. All classes of astromaterials studied show some degree of interaction with aqueous fluids. Nevertheless, we are still lacking fundamental information such as the location and timing of the aqueous alteration and the detailed nature of the aqueous fluids. Halite crystals in two meteorite regolith breccias were found to contain aqueous fluid inclusions (brines) trapped approx. 4.5 BYBP. Heating/freezing studies of the aqueous fluid inclusions in these halites demonstrated that they were trapped near 25 C. The initial results of our O and H isotopic measurements on these brine inclusions can be explained by a simple model mixing asteroidal and cometary water. We have been analyzing solids and organics trapped alongside the brines in the halites by FTIR, C-XANES, SXRD and Raman, as clues to the origin of the water. The organics show thermal effects that span the entire range witnessed by organics in all chondrite types. Since we identified water-soluble aromatics, including partially halogenated methanol, in some of the halite, we suspected amino acids were also present, but have thus far found that levels of amino acids were undetectable (which is very interesting). We have also been locating aqueous fluid inclusions in other astromaterials, principally carbonates in CI and CM chondrites. Although we have advanced slowly towards detailed analysis of these ancient brines, since they require techniques right at or just beyond current analytical capabilities, their eventual full characterization will completely open the window onto the origin and activity of early solar system water.

  20. The reconstruction of solar activity in the context of solar dynamo modeling

    Science.gov (United States)

    Sokoloff, D.

    2017-01-01

    We discuss problems of interpretation of sunspot data for use in solar dynamo modelling. The variety of the current sunspot reconstructions of archival data creates substantial difficulties for such an endeavour. We suggest a possible strategy to avoid these problems. The point is that we have to accept the possibility of several solar activity reconstructions that are contradictory in detail, and have to compare several possible reconstructions with dynamo models. The point is that a given reconstruction may not cover all the time interval of interest because this reconstruction requires information unavailable at earlier or later times.

  1. Measurements and Modeling of Total Solar Irradiance in X-Class Solar Flares

    CERN Document Server

    Moore, Christopher Samuel; Hock, Rachel

    2015-01-01

    The Total Irradiance Monitor (TIM) from NASA's SOlar Radiation and Climate Experiment (SORCE) can detect changes in the Total Solar Irradiance (TSI) to a precision of 2 ppm, allowing observations of variations due to the largest X-Class solar ares for the first time. Presented here is a robust algorithm for determining the radiative output in the TIM TSI measurements, in both the impulsive and gradual phases, for the four solar ares presented in Woods et al. (2006), as well as an additional are measured on 2006 December 6. The radiative outputs for both phases of these five ares are then compared to the Vacuum Ultraviolet (VUV) irradiance output from the Flare Irradiance Spectral Model (FISM) in order to derive an empirical relationship between the FISM VUV model and the TIM TSI data output to estimate the TSI radiative output for eight other X-Class ares. This model provides the basis for the bolometric energy estimates for the solar ares analyzed in the Emslie et al. (2012) study.

  2. Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

    OpenAIRE

    Thomas Semenou; Rousse, Daniel R.; Brice Le Lostec; Hervé F. Nouanegue; Pierre-Luc Paradis

    2015-01-01

    Nowadays, in several types of commercial or institutional buildings, a significant rise of transpired solar collectors used to preheat the fresh air of the building can be observed. Nevertheless, when the air mass flow rate is low, the collector efficiency collapses and a large amount of energy remains unused. This paper presents a simple yet effective mathematical model of a transparent transpired solar collector (TTC) with dual intake in order to remove stagnation problems in the plenum and...

  3. PREDICTION OF OPTIMUM ANGLE OF SOLAR WATER HEATER FOR COIMBATORE LOCATION

    OpenAIRE

    M. Sekar; DR M. SAKTHIVEL; O. MANIYARASU; N.ALAGU MURUGAN

    2013-01-01

    The objective of this work was to investigate ways to enhance the performance of solar water heater system to encourage many households using it. The integrated collector storage is the type of solar water heater that has retained its existence for well over a century. The flat absorber plate integrated collector storage type is a relatively recent addition. Being effective, low cost and simple to manufacture, their importance has been further enhanced by the recent upsurge in efforts to effe...

  4. A radiative transfer module for calculating photolysis rates and solar heating in climate models: Solar-J v7.5

    Directory of Open Access Journals (Sweden)

    J. Hsu

    2017-07-01

    Full Text Available Solar-J is a comprehensive radiative transfer model for the solar spectrum that addresses the needs of both solar heating and photochemistry in Earth system models. Solar-J is a spectral extension of Cloud-J, a standard in many chemical models that calculates photolysis rates in the 0.18–0.8 µm region. The Cloud-J core consists of an eight-stream scattering, plane-parallel radiative transfer solver with corrections for sphericity. Cloud-J uses cloud quadrature to accurately average over correlated cloud layers. It uses the scattering phase function of aerosols and clouds expanded to eighth order and thus avoids isotropic-equivalent approximations prevalent in most solar heating codes. The spectral extension from 0.8 to 12 µm enables calculation of both scattered and absorbed sunlight and thus aerosol direct radiative effects and heating rates throughout the Earth's atmosphere.The Solar-J extension adopts the correlated-k gas absorption bins, primarily water vapor, from the shortwave Rapid Radiative Transfer Model for general circulation model (GCM applications (RRTMG-SW. Solar-J successfully matches RRTMG-SW's tropospheric heating profile in a clear-sky, aerosol-free, tropical atmosphere. We compare both codes in cloudy atmospheres with a liquid-water stratus cloud and an ice-crystal cirrus cloud. For the stratus cloud, both models use the same physical properties, and we find a systematic low bias of about 3 % in planetary albedo across all solar zenith angles caused by RRTMG-SW's two-stream scattering. Discrepancies with the cirrus cloud using any of RRTMG-SW's three different parameterizations are as large as about 20–40 % depending on the solar zenith angles and occur throughout the atmosphere.Effectively, Solar-J has combined the best components of RRTMG-SW and Cloud-J to build a high-fidelity module for the scattering and absorption of sunlight in the Earth's atmosphere, for which the three major components – wavelength

  5. A radiative transfer module for calculating photolysis rates and solar heating in climate models: Solar-J v7.5

    Science.gov (United States)

    Hsu, Juno; Prather, Michael J.; Cameron-Smith, Philip; Veidenbaum, Alex; Nicolau, Alex

    2017-07-01

    Solar-J is a comprehensive radiative transfer model for the solar spectrum that addresses the needs of both solar heating and photochemistry in Earth system models. Solar-J is a spectral extension of Cloud-J, a standard in many chemical models that calculates photolysis rates in the 0.18-0.8 µm region. The Cloud-J core consists of an eight-stream scattering, plane-parallel radiative transfer solver with corrections for sphericity. Cloud-J uses cloud quadrature to accurately average over correlated cloud layers. It uses the scattering phase function of aerosols and clouds expanded to eighth order and thus avoids isotropic-equivalent approximations prevalent in most solar heating codes. The spectral extension from 0.8 to 12 µm enables calculation of both scattered and absorbed sunlight and thus aerosol direct radiative effects and heating rates throughout the Earth's atmosphere.The Solar-J extension adopts the correlated-k gas absorption bins, primarily water vapor, from the shortwave Rapid Radiative Transfer Model for general circulation model (GCM) applications (RRTMG-SW). Solar-J successfully matches RRTMG-SW's tropospheric heating profile in a clear-sky, aerosol-free, tropical atmosphere. We compare both codes in cloudy atmospheres with a liquid-water stratus cloud and an ice-crystal cirrus cloud. For the stratus cloud, both models use the same physical properties, and we find a systematic low bias of about 3 % in planetary albedo across all solar zenith angles caused by RRTMG-SW's two-stream scattering. Discrepancies with the cirrus cloud using any of RRTMG-SW's three different parameterizations are as large as about 20-40 % depending on the solar zenith angles and occur throughout the atmosphere.Effectively, Solar-J has combined the best components of RRTMG-SW and Cloud-J to build a high-fidelity module for the scattering and absorption of sunlight in the Earth's atmosphere, for which the three major components - wavelength integration, scattering, and

  6. Application of solar hot water and geothermal principles to closed-cycle aquaculture

    Science.gov (United States)

    Yanzito, R. A.

    1981-04-01

    The design of an underground silo where warm water food fish could be raised to market size under controlled conditions. The building and solar concept analysis for the closed cycle aquaculture system are described. Energy conservation features of the design include Earth berming and insulation of the production silo and enclosure, a waste water reclaim system and a solar heating system. Much of the water surface area is covered with removable plants to minimize evaporative heat losses. An energy conservation analysis is also reported and the F-Chart computer program is described. The system chosen utilizes single glazed flat plate collectors in a closed loop antifreeze system. Makeup water is introduced during an 8 hour period each day. Solar energy is transferred from the antifreeze solution to the makeup water after it leaves the waste water heat exchanger.

  7. SRADLIB: A C Library for Solar Radiation Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Balenzategui, J. L. [Ciemat. Madrid (Spain)

    2000-07-01

    This document shows the result of an exhaustive study about the theoretical and numerical models available in the literature about solar radiation modelling. The purpose of this study is to develop or adapt mathematical models describing the solar radiation specifically for Spain locations as well as to create computer tools able to support the labour of researchers or engineers needing solar radiation data to solve or improve the technical or energetic performance of solar systems. As results of this study and revision, a C library (SRADLIB) is presented as a key for the compilation of the mathematical models from different authors, for the comparison among the different approaches and for its application in computer programs. Different topics related to solar radiation and its modelling are first discussed, including the assumptions and conventions adopted and describing the most accepted and used current state-of-the-art models. some typical problems in the numerical calculation of radiation values are also posed with the proposed solution. The document includes next a complete reference of the developed functions, with many examples of application and calculus. (Author) 24 refs.

  8. Solar production of industrial process hot water: operation and evaluation of the Campbell Soup hot water solar facility. Final report, September 1, 1979-December 10, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Kull, J. I.; Niemeyer, W. N.; Youngblood, S. B.

    1980-12-01

    The operation and evaluation of a solar hot water facility designed by Acurex Corporation and installed (November 1977) at the Campbell Soup Company Sacramento, California canning plant is summarized. The period of evaluation was for 12 months from October 1979 through September 1980. The objective of the work was to obtain additional, long term data on the operation and performance of the facility. Minor modifications to the facility were completed. The system was operated for 15 months, and 12 months of detailed data were evaluated. The facility was available for operation 99% of the time during the last 8 months of evaluation. A detailed description of the solar facility and of the operating experience is given, and a summary of system performance for the 12 month operation/evaluation period is presented. Recommendations for large-scale solar facilities based on this project's experience are given, and an environmental impact assessment for the Campbell Soup solar facility is provided. (WHK)

  9. A Compound model for the origin of Earth's water

    CERN Document Server

    Torres, K de Souza; Izidoro, A; Haghighipour, N

    2013-01-01

    One of the most important subjects of debate in the formation of the solar system is the origin of Earth's water. Comets have long been considered as the most likely source of the delivery of water to Earth. However, elemental and isotopic arguments suggest a very small contribution from these objects. Other sources have also been proposed, among which, local adsorption of water vapor onto dust grains in the primordial nebula and delivery through planetesimals and planetary embryos have become more prominent. However, no sole source of water provides a satisfactory explanation for Earth's water as a whole. In view of that, using numerical simulations, we have developed a compound model incorporating both the principal endogenous and exogenous theories, and investigating their implications for terrestrial planet formation and water-delivery. Comets are also considered in the final analysis, as it is likely that at least some of Earth's water has cometary origin. We analyze our results comparing two different w...

  10. Model document for code officials on solar heating and cooling of buildings. Second draft

    Energy Technology Data Exchange (ETDEWEB)

    Trant, B. S.

    1979-09-01

    Guidelines and codes for the construction, alteration, moving, demolition, repair and use of solar energy systems and parts thereof used for space heating and cooling, for water heating and for processing purposes in, on, or adjacent to buildings and appurtenant structures are presented. The necessary references are included wherever these provisions affect or are affected by the requirments of nationally recognized standards or model codes. The purpose of this document is to safeguard life and limb, health, property and public welfare by regulating and controlling the design, construction, quality of materials, location and maintenance of solar energy systems in, on, or adjacent to buildings and appurtenant structures.

  11. The EPANET water quality model

    Energy Technology Data Exchange (ETDEWEB)

    Rossman, L.A. [Environmental Protection Agency, Cincinnati, OH (United States)

    1995-10-01

    EPANET is a software package developed by US EPA`s Drinking Water Research Division for modeling hydraulic and water quality behavior within water distribution systems. Starting with a geometric description of the pipe network, a set of initial conditions, estimates of water usage, and a set of rules for how the system is operated, EPANET predicts all flows, pressures, and water quality levels throughout the network during an extended period of operation. In addition to substance concentration, water age and source tracing can also be simulated. EPANET offers a number of advanced features including: modular, highly portable C language code with no pre-set limits on network size; a simple data input format based on a problem oriented language; a full-featured hydraulic simulator; improved water quality algorithms; analysis of water quality reactions both within the bulk flow and at the pipe wall; an optional graphical user interface running under Microsoft{reg_sign} Windows{trademark}. The Windows user interface allows one to edit EPANET input files, run a simulation, and view the results all within a single program. Simulation output can be visualized through: color-coded maps of the distribution system with full zooming, panning and labeling capabilities and a slider control to move forward or backward through time; spreadsheet-like tables that can be searched for entries meeting a specified criterion; and time series graphs of both predicted and observed values for any variable at any location in the network. EPANET is currently being used to analyze a number of water quality issues in different distribution systems across the country. These include: chlorine decay dynamics, raw water source blending, altered tank operation, and integration with real-time monitoring and control systems.

  12. Water Distribution and Removal Model

    Energy Technology Data Exchange (ETDEWEB)

    Y. Deng; N. Chipman; E.L. Hardin

    2005-08-26

    The design of the Yucca Mountain high level radioactive waste repository depends on the performance of the engineered barrier system (EBS). To support the total system performance assessment (TSPA), the Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is developed to describe the thermal, mechanical, chemical, hydrological, biological, and radionuclide transport processes within the emplacement drifts, which includes the following major analysis/model reports (AMRs): (1) EBS Water Distribution and Removal (WD&R) Model; (2) EBS Physical and Chemical Environment (P&CE) Model; (3) EBS Radionuclide Transport (EBS RNT) Model; and (4) EBS Multiscale Thermohydrologic (TH) Model. Technical information, including data, analyses, models, software, and supporting documents will be provided to defend the applicability of these models for their intended purpose of evaluating the postclosure performance of the Yucca Mountain repository system. The WD&R model ARM is important to the site recommendation. Water distribution and removal represents one component of the overall EBS. Under some conditions, liquid water will seep into emplacement drifts through fractures in the host rock and move generally downward, potentially contacting waste packages. After waste packages are breached by corrosion, some of this seepage water will contact the waste, dissolve or suspend radionuclides, and ultimately carry radionuclides through the EBS to the near-field host rock. Lateral diversion of liquid water within the drift will occur at the inner drift surface, and more significantly from the operation of engineered structures such as drip shields and the outer surface of waste packages. If most of the seepage flux can be diverted laterally and removed from the drifts before contacting the wastes, the release of radionuclides from the EBS can be controlled, resulting in a proportional reduction in dose release at the accessible environment. The purposes

  13. Influence of orbital forcing and solar activity on water isotopes in precipitation during the mid- and late Holocene

    Directory of Open Access Journals (Sweden)

    S. Dietrich

    2013-01-01

    Full Text Available In this study we investigate the impact of mid- and late Holocene orbital forcing and solar activity on variations of the oxygen isotopic composition in precipitation. The investigation is motivated by a recently published speleothem δ18O record from the well-monitored Bunker Cave in Germany. The record reveals some high variability on multi-centennial to millennial scales that does not linearly correspond to orbital forcing. Our model study is based on a set of novel climate simulations performed with the atmosphere general circulation model ECHAM5-wiso enhanced by explicit water isotope diagnostics. From the performed model experiments, we derive the following major results: (1 the response of both orbital and solar forcing lead to changes in surface temperatures and δ18O in precipitation with similar magnitudes during the mid- and late Holocene. (2 Past δ18O anomalies correspond to changing temperatures in the orbital driven simulations. This does not hold true if an additional solar forcing is added. (3 Two orbital driven mid-Holocene experiments, simulating the mean climate state approximately 5000 and 6000 yr ago, yield very similar results. However, if an identical additional solar activity-induced forcing is added, the simulated changes of surface temperatures as well as δ18O between both periods differ. We conclude from our simulation results that non-linear effects and feedbacks of the orbital and solar activity forcing substantially alter the δ18O in precipitation pattern and its relation to temperature change.

  14. Production of solar radiation bankable datasets from high-resolution solar irradiance derived with dynamical downscaling Numerical Weather prediction model

    Directory of Open Access Journals (Sweden)

    Yassine Charabi

    2016-11-01

    Full Text Available A bankable solar radiation database is required for the financial viability of solar energy project. Accurate estimation of solar energy resources in a country is very important for proper siting, sizing and life cycle cost analysis of solar energy systems. During the last decade an important progress has been made to develop multiple solar irradiance database (Global Horizontal Irradiance (GHI and Direct Normal Irradiance (DNI, using satellite of different resolution and sophisticated models. This paper assesses the performance of High-resolution solar irradiance derived with dynamical downscaling Numerical Weather Prediction model with, GIS topographical solar radiation model, satellite data and ground measurements, for the production of bankable solar radiation datasets. For this investigation, NWP model namely Consortium for Small-scale Modeling (COSMO is used for the dynamical downscaling of solar radiation. The obtained results increase confidence in solar radiation data base obtained from dynamical downscaled NWP model. The mean bias of dynamical downscaled NWP model is small, on the order of a few percents for GHI, and it could be ranked as a bankable datasets. Fortunately, these data are usually archived in the meteorological department and gives a good idea of the hourly, monthly, and annual incident energy. Such short time-interval data are valuable in designing and operating the solar energy facility. The advantage of the NWP model is that it can be used for solar radiation forecast since it can estimate the weather condition within the next 72–120 hours. This gives a reasonable estimation of the solar radiation that in turns can be used to forecast the electric power generation by the solar power plant.

  15. Economic Investigation of Different Configurations of Inclined Solar Water Desalination Systems

    Directory of Open Access Journals (Sweden)

    O. Phillips Agboola

    2014-02-01

    Full Text Available This study empirically investigated the performance of four configurations of inclined solar water desalination (ISWD system for parameters such as daily production, efficiency, system cost, and distilled water production cost. The empirical findings show that in terms of daily productivity improved inclined solar water desalination (IISWD performed best with 6.41 kg/m2/day while improved inclined solar water desalination with wire mesh (IISWDWM produced the least with 3.0 kg/m2/day. In terms of cost price of the systems, the control system inclined solar water desalination (ISWD is the cheapest while IISWDWM is the most expensive system. Distilled water cost price ranges from 0.059 TL/kg, for IISWDW, to 0.134 TL/kg, for IISWDWM system. All the systems are economically and technically feasible as a solar desalination system for potable water in northern Cyprus. Potable water from vendors/hawkers ranges from 0.2 to 0.3 TL/kg.

  16. Experimental comparison of alternative convection suppression arrangements for concentrating integral collector storage solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, M.; McGarrigle, P.; Eames, P.C. [Ulster Univ., School of the Built Environment, Newtownabbey, Northern Ireland (United Kingdom); Norton, B. [Dublin Inst. of Technology, Dublin (Ireland)

    2005-02-01

    An experimental investigation of an inverted absorber integrated collector storage solar water heater mounted in the tertiary cavity of a compound parabolic concentrator with a secondary cylindrical reflector has been performed under simulated solar conditions. The solar water heaters performance was determined with the aperture parallel to the simulator for a range of transparent baffles positioned at different locations within the collector cavity. Results indicate that glass baffles located at the upper portion of the exit aperture of the CPC can reduce thermal losses through convection suppression without significantly increasing optical losses. (Author)

  17. Solar Hydrogen Production via a Samarium Oxide-Based Thermochemical Water Splitting Cycle

    OpenAIRE

    Rahul Bhosale; Anand Kumar; Fares AlMomani; Ujjal Ghosh; Mohammad Saad Anis; Konstantinos Kakosimos; Rajesh Shende; Marc A. Rosen

    2016-01-01

    The computational thermodynamic analysis of a samarium oxide-based two-step solar thermochemical water splitting cycle is reported. The analysis is performed using HSC chemistry software and databases. The first (solar-based) step drives the thermal reduction of Sm2O3 into Sm and O2. The second (non-solar) step corresponds to the production of H2 via a water splitting reaction and the oxidation of Sm to Sm2O3. The equilibrium thermodynamic compositions related to the thermal reduction and wat...

  18. Solar Energy for Domestic Hot Water: Case Studies in Sisimiut 1999-2005

    DEFF Research Database (Denmark)

    Reimann, Gregers Peter

    2005-01-01

    Two pioneer solar domestic hot water systems were installed at Bygge- og Anlægsskolen in Sisimiut in 1999 and 2000. Detailed measurements of energy flows and solar radiation incl. snow reflectance has been undertaken for both plants. Since August 2004 data logging of the measurements was made...... available online on the website www.arcticsolar.com. Measurements show that solar plant 1 and 2 cover 22% and 23%, respectively, of the energy spent for domestic hot water heating. This paper summarises the findings from the past 5 years....

  19. Solar Energy for Domestic Hot Water: Case Studies in Sisimiut 1999-2005

    DEFF Research Database (Denmark)

    Reimann, Gregers Peter

    2005-01-01

    Two pioneer solar domestic hot water systems were installed at Bygge- og Anlægsskolen in Sisimiut in 1999 and 2000. Detailed measurements of energy flows and solar radiation incl. snow reflectance has been undertaken for both plants. Since August 2004 data logging of the measurements was made...... available online on the website www.arcticsolar.com. Measurements show that solar plant 1 and 2 cover 22% and 23%, respectively, of the energy spent for domestic hot water heating. This paper summarises the findings from the past 5 years....

  20. PERFORMANCE OF EVACUATED TUBE SOLAR COLLECTOR USING WATER-BASED TITANIUM OXIDE NANOFLUID

    OpenAIRE

    M. Mahendran; Lee, G C; Sharma, K. V.; A. Shahrani; R. A. Bakar

    2012-01-01

    Experiments are undertaken to determine the efficiency of an evacuated tube solar collector using water-based Titanium Oxide (TiO2) nanofluid at the Pekan Campus (3˚32’ N, 103˚25’ E), Faculty of Mechanical Engineering, University Malaysia Pahang, for the conversion of solar thermal energy. Malaysia lies in the equatorial zone with an average daily solar insolation of more than 900 W/m², which can reach a maximum of 1200 W/m² for most of the year. Traditionally water is pumped through the coll...