Interior design for passive solar homes

Energy Technology Data Exchange (ETDEWEB)

Breen, J. C.

1981-07-01

The increasing emphasis on refinement of passive solar systems has brought recognition to interior design as an integral part of passive solar architecture. Interior design can be used as a finetuning tool minimizing many of the problems associated with passive solar energy use in residential buildings. In addition, treatment of interior space in solar model homes may be a prime factor in determining sales success. A new style of interior design is evolving in response to changes in building form incorporating passive solar design features. The psychology behind passive solar architecture is reflected in interiors, and selection of interior components increasingly depends on the functional suitability of various interior elements.

Use of passive solar architecture design in energy saving, Morena tourist village

Energy Technology Data Exchange (ETDEWEB)

Mina, M.B.

1993-12-31

This document deals with energy saving in buildings,more precisely in the Morena tourist village. The concept of passive solar technology is developed in villas. The first prototype enabled to have measurements of temperatures and thermal graphs. A comparison between the initial architectural design and this prototype shows the efficiency of the use of passive solar energy (energy and money saving). (TEC). 5 figs., 1 tab.

Use of passive solar architecture design in energy saving, Morena tourist village

Energy Technology Data Exchange (ETDEWEB)

Mina, M B

1994-12-31

This document deals with energy saving in buildings,more precisely in the Morena tourist village. The concept of passive solar technology is developed in villas. The first prototype enabled to have measurements of temperatures and thermal graphs. A comparison between the initial architectural design and this prototype shows the efficiency of the use of passive solar energy (energy and money saving). (TEC). 5 figs., 1 tab.

Thermal Stability-Enhanced and High-Efficiency Planar Perovskite Solar Cells with Interface Passivation.

Science.gov (United States)

Zhang, Weihai; Xiong, Juan; Jiang, Li; Wang, Jianying; Mei, Tao; Wang, Xianbao; Gu, Haoshuang; Daoud, Walid A; Li, Jinhua

2017-11-08

As the electron transport layer (ETL) of perovskite solar cells, oxide semiconductor zinc oxide (ZnO) has been attracting great attention due to its relatively high mobility, optical transparency, low-temperature fabrication, and good environment stability. However, the nature of ZnO will react with the patron on methylamine, which would deteriorate the performance of cells. Although many methods, including high-temperature annealing, doping, and surface modification, have been studied to improve the efficiency and stability of perovskite solar cells with ZnO ETL, devices remain relatively low in efficiency and stability. Herein, we adopted a novel multistep annealing method to deposit a porous PbI 2 film and improved the quality and uniformity of perovskite films. The cells with ZnO ETL were fabricated at the temperature of perovskite film. Interestingly, the PCE of PCBM-passivated cells could reach nearly 19.1%. To our best knowledge, this is the highest PCE value of ZnO-based perovskite solar cells until now. More importantly, PCBM modification could effectively suppress the decomposition of MAPbI 3 and improve the thermal stability of cells. Therefore, the ZnO is a promising candidate of electron transport material for perovskite solar cells in future applications.

Advanced Passivation Technology and Loss Factor Minimization for High Efficiency Solar Cells.

Science.gov (United States)

Park, Cheolmin; Balaji, Nagarajan; Jung, Sungwook; Choi, Jaewoo; Ju, Minkyu; Lee, Seunghwan; Kim, Jungmo; Bong, Sungjae; Chung, Sungyoun; Lee, Youn-Jung; Yi, Junsin

2015-10-01

High-efficiency Si solar cells have attracted great attention from researchers, scientists, photovoltaic (PV) industry engineers for the past few decades. With thin wafers, surface passivation becomes necessary to increase the solar cells efficiency by overcoming several induced effects due to associated crystal defects and impurities of c-Si. This paper discusses suitable passivation schemes and optimization techniques to achieve high efficiency at low cost. SiNx film was optimized with higher transmittance and reduced recombination for using as an effective antireflection and passivation layer to attain higher solar cell efficiencies. The higher band gap increased the transmittance with reduced defect states that persisted at 1.68 and 1.80 eV in SiNx films. The thermal stability of SiN (Si-rich)/SiN (N-rich) stacks was also studied. Si-rich SiN with a refractive index of 2.7 was used as a passivation layer and N-rich SiN with a refractive index of 2.1 was used for thermal stability. An implied Voc of 720 mV with a stable lifetime of 1.5 ms was obtained for the stack layer after firing. Si-N and Si-H bonding concentration was analyzed by FTIR for the correlation of thermally stable passivation mechanism. The passivation property of spin coated Al2O3 films was also investigated. An effective surface recombination velocity of 55 cm/s with a high density of negative fixed charges (Qf) on the order of 9 x 10(11) cm(-2) was detected in Al2O3 films.

Enhanced Charge Collection with Passivation Layers in Perovskite Solar Cells.

Science.gov (United States)

Lee, Yong Hui; Luo, Jingshan; Son, Min-Kyu; Gao, Peng; Cho, Kyung Taek; Seo, Jiyoun; Zakeeruddin, Shaik M; Grätzel, Michael; Nazeeruddin, Mohammad Khaja

2016-05-01

The Al2 O3 passivation layer is beneficial for mesoporous TiO2 -based perovskite solar cells when it is deposited selectively on the compact TiO2 surface. Such a passivation layer suppressing surface recombination can be formed by thermal decomposition of the perovskite layer during post-annealing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High performance passive solar heating system with heat pipe energy transfer

NARCIS (Netherlands)

Wit, de M.H.; Hensen, J.L.M.; Dijk, van H.A.L.; Brink, van den G.J.; Galen, van E; Ouden, den C.

1984-01-01

The aim of the project is to develop a passive solar heating system with a higher efficiency (regarding accumulation and transfer of solar heat into dwellings) than convential concrete thermal storage walls and with restricted extra costs for manufacturing the system. This is to be achieved by the

Energy efficiency and comfort conditions in passive solar buildings: Effect of thermal mass at equatorial high altitudes

Science.gov (United States)

Ogoli, David Mwale

This dissertation is based on the philosophy that architectural design should not just be a function of aesthetics, but also of energy-efficiency, advanced technologies and passive solar strategies. A lot of published literature is silent regarding buildings in equatorial highland regions. This dissertation is part of the body of knowledge that attempts to provide a study of energy in buildings using thermal mass. The objectives were to establish (1) effect of equatorial high-altitude climate on thermal mass, (2) effect of thermal mass on moderating indoor temperatures, (3) effect of thermal mass in reducing heating and cooling energy, and (4) the amount of time lag and decrement factor of thermal mass. Evidence to analyze the effect of thermal mass issues came from three sources. First, experimental physical models involving four houses were parametrically conducted in Nairobi, Kenya. Second, energy computations were made using variations in thermal mass for determining annual energy usage and costs. Third, the data gathered were observed, evaluated, and compared with currently published research. The findings showed that: (1) Equatorial high-altitude climates that have diurnal temperature ranging about 10--15°C allow thermal mass to moderate indoor temperatures; (2) Several equations were established that indicate that indoor mean radiant temperatures can be predicted from outdoor temperatures; (3) Thermal mass can reduce annual energy for heating and cooling by about 71%; (4) Time lag and decrement of 200mm thick stone and concrete thermal mass can be predicted by a new formula; (5) All windows on a building should be shaded. East and west windows when shaded save 51% of the cooling energy. North and south windows when fully shaded account for a further 26% of the cooling energy; (6) Insulation on the outside of a wall reduces energy use by about 19.6% below the levels with insulation on the inside. The basic premise of this dissertation is that decisions that

Past, present and future of passive homes in solar village 3, Athens

Science.gov (United States)

Kalogridis, Achilles

Solar village 3 in Pefki, Athens, was part of an ambitious program for the promotion of solar technology, applied to a large scale social housing scheme, designed in mid 80's and firstly inhabited in the early 1990's. Among the aims of the project was the demonstration of the latest of technology in active solar systems and passive techniques, incorporated in a new settlement's layout and houses' building envelop, in order to create an energy saving, comfortable environment. More than fifteen years later, the housing complex remains the largest residential development of bioclimatic "solar" architecture in Athens, with the active and passive solar systems providing space and water heating for about 1750 inhabitants. The study focuses in the passive solar systems that have been applied to a number of the buildings of the settlement. The systems provide space heating with no need of any active mechanism, however with demand of the participation of the end users for their proper operation. The essay reviews various previous studies, monitoring reports and criticisms that have appeared throughout the past years, and identifies how the houses perform today, through a recent survey, sample monitoring and thermal comfort simulation. The report records things that have changed, features which worked well or others that did not and comments on the residents' behaviour. Interesting findings come into question, regarding the passive solar systems, their integration into the building's design, their current condition and their contribution to energy savings and thermal comfort conditions. Finally, current plans concerning the future of the settlement are highlighted, and considerations about the houses sustainability are suggested.

Passive solar heating

Energy Technology Data Exchange (ETDEWEB)

Wiberg, K

1981-11-10

The present work treats the possibilities for heating according to the passive solar heating method. Problems of 'spatial organization in an energy-saving society' are distinguished from among other social problems. The final delimination of the actual problems under investigation consists of the use of passive solar heating and especially the 'consequences of such solar heating exploitation upon the form and structures' of planning and construction. In the concluding chapter an applied example shows how this method can be used in designing an urban area and what are its limitations. The results indicate the possibilities and difficulties in attempting to transfer this ideal and general method into models and directives for form and structure from which examples of the actual possibilities in practical planning can be given.

Thermal Feature of a Modified Solar Phase Change Material Storage Wall System

Directory of Open Access Journals (Sweden)

Chenglong Luo

2018-01-01

Full Text Available This work is to study a novel solar PCM storage wall technology, that is, a dual-channel and thermal-insulation-in-the-middle type solar PCM storage wall (MSPCMW system. The system has the following four independent functions, passive solar heating, heat preservation, heat insulation, and passive cooling, and it can agilely cope with the requirements of climatization of buildings in different seasons throughout the year and is exactly suitable for building in regions characterized by hot summer and cold winter. The present work experimentally analyzes thermal feature of the system working in summer and winter modes, respectively.

A new insight into opaque envelopes in a passive solar house: Properties and roles

International Nuclear Information System (INIS)

Long, Linshuang; Ye, Hong; Liu, Minghou

2016-01-01

Highlights: • A new insight into the opaque envelopes of a passive solar house was gained. • Five parts of envelopes, i.e., roof, south/east/west/north walls, were discussed. • Each part of envelopes were analyzed separately rather than treated as a whole. • Ideal properties of materials for each envelope are diverse from one another. • Differences are related to the envelopes’ leading roles as a heater or a cooler. - Abstract: Passive solar houses are effective solutions for minimizing the operating energy of buildings. The building envelopes of passive solar houses exert a significant influence on the degree of indoor thermal comfort. The focus of this study was the construction of high-performance opaque envelopes, i.e., the roof and walls, for a passive solar house, and a new conception of the envelopes from the perspective of the relation between the properties and roles was provided. The discussion was conducted based on a comprehensive range of envelope materials that were distinguished by the thermal conductivity and volumetric heat capacity. For the first time, each part of the envelopes was analyzed separately rather than considered as an entire envelope. By analyzing each envelope individually, the optimum properties of each envelope were found to be distinct from each other. The distinctions are determined by the dominant role of each envelope, which is associated with the location and absorbed solar irradiation. For summer or hot climate applications, when the dominant role is a cooler, the envelope, e.g., the south wall, should consist of materials with high thermal conductivity and large heat capacity; if a heater is the dominant role, the envelope, e.g., the roof, should consist of materials with low thermal conductivity. For winter or cold climate applications, the envelopes with a leading role of a heater or a cooler require materials with high or low thermal conductivity, respectively. Under the guidance of the results, a discussion

Design, fabrication and performance of a hybrid photovoltaic/thermal (PV/T) active solar still

International Nuclear Information System (INIS)

Kumar, Shiv; Tiwari, Arvind

2010-01-01

Two solar stills (single slope passive and single slope photovoltaic/thermal (PV/T) active solar still) were fabricated and tested at solar energy park, IIT New Delhi (India) for composite climate. Photovoltaic operated DC water pump was used between solar still and photovoltaic (PV) integrated flat plate collector to re-circulate the water through the collectors and transfer it to the solar still. The newly designed hybrid (PV/T) active solar still is self-sustainable and can be used in remote areas, need to transport distilled water from a distance and not connected to grid, but blessed with ample solar energy. Experiments were performed for 0.05, 0.10, and 0.15 m water depth, round the year 2006-2007 for both the stills. It has been observed that maximum daily yield of 2.26 kg and 7.22 kg were obtained from passive and hybrid active solar still, respectively at 0.05 m water depth. The daily yield from hybrid active solar still is around 3.2 and 5.5 times higher than the passive solar still in summer and winter month, respectively. The study has shown that this design of the hybrid active solar still also provides higher electrical and overall thermal efficiency, which is about 20% higher than the passive solar still.

A passive solar heater-refrigerator

International Nuclear Information System (INIS)

D'Isep, F.; Sertorio, L.

1983-01-01

In this paper it is studied the nonequilibrium thermodynamic steady-state behaviour of a model system representing a core surrounded by an envelope in which the envelope interacts with the solar radiation and with an external bath having a given temperature profile. The heat flow between core and envelope can be controlled by varying the thermal conductivity of their interface. It is shown that this system acts as a passive heat pump raising the core average temperature with respect to the average equilibrium value corresponding to a fixed value of the interface conductivity, at the same time flattening its oscillation in time. By changing the time dependence of the conductivity the system vice versa acts as a refrigerator. It is shown how the limits of this performance depend on the passive parameters such as surfaces, conductivities, heat capacities. The periodicity considered in this study is the daily cycle

Performance of passive solar and energy conserving houses in California

Science.gov (United States)

Mahajan, S.; Newcomb, C.; Shea, M.; Mort, D.

1983-11-01

This report provides a technical description of the methodology and the results of a two year effort to collect field data on the performance of passive solar and energy conserving houses in California. Sixty-three passive solar houses were visited and several hours were spent with the homeowner obtaining building details, management procedures, architectural plans, photographs, and at least a year of billing data. With this information thermal performance parameters were calculated for each of the houses. Eleven of the above sixty-three Class C sites (nine passive solar and two energy conserving houses) were instrumented and monitored using the SERI Class B methodology as a guideline. Continuous data were collected for one year using up to 18 different sensors to measure temperatures, electric power, insolation, and the status of fans, gas burners, and moveable insulation. In addition careful one time measurements were made to determine the loss coefficient, infiltration rate, and furnace efficiency. Analysis of this data giving comfort conditions maintained and energy uses for a complete heating and cooling season for each of the houses is presented.

Passive Q switching of a solar-pumped Nd:YAG laser.

Science.gov (United States)

Lando, M; Shimony, Y; Noter, Y; Benmair, R M; Yogev, A

2000-04-20

Passive Q switching is a preferable choice for switching the Q factor of a solar-pumped laser because it requires neither a driver nor an electrical power supply. The superior thermal characteristics and durability of Cr(4+):YAG single crystals as passive Q switches for lamp and diode-pumped high-power lasers has been demonstrated. Here we report on an average power of 37 W and a switching efficiency of 80% obtained by use of a solar-pumped Nd:YAG laser Q switched by a Cr(4+):YAG saturable absorber. Concentration of the pumping solar energy on the laser crystal was obtained with a three-stage concentrator, composed of 12 heliostats, a three-dimensional compound parabolic concentrator (CPC) and a two-dimensional CPC. The water-cooled passive Q switch also served as the laser rear mirror. Repetition rates of as much as 50 kHz, at pulse durations between 190 and 310 ns (FWHM) were achieved. From the experimental results, the saturated single-pass power absorption of the Cr(4+):YAG device was estimated as 3 ? 1%.

THE USE OF PASSIVE SOLAR HEATING SYSTEMS AS PART OF THE PASSIVE HOUSE

Directory of Open Access Journals (Sweden)

Bryzgalin Vladislav Viktorovich

2018-05-01

Full Text Available Subject: systems of passive solar heating, which can, without the use of engineering equipment, capture and accumulate the solar heat used for heating buildings. Research objectives: study of the possibility to reach the passive house standard (buildings with near zero energy consumption for heating in climatic conditions of Russia using the systems of passive solar heating in combination with other solutions for reduction of energy costs of building developed in the past. Materials and methods: search and analysis of literature, containing descriptions of various passive solar heating systems, examples of their use in different climatic conditions and the resulting effect obtained from their use; analysis of thermophysical processes occurring in these systems. Results: we revealed the potential of using the solar heating systems in the climatic conditions of parts of the territories of the Russian Federation, identified the possibility of cheaper construction by the passive house standard with the use of these systems. Conclusions: more detailed analysis of thermophysical and other processes that take place in passive solar heating systems is required for creation of their computational models, which will allow us to more accurately predict their effectiveness and seek the most cost-effective design solutions, and include them in the list of means for achieving the passive house standard.

Thermal Feature of a Modified Solar Phase Change Material Storage Wall System

OpenAIRE

Luo, Chenglong; Xu, Lijie; Ji, Jie; Liao, Mengyin; Sun, Dan

2018-01-01

This work is to study a novel solar PCM storage wall technology, that is, a dual-channel and thermal-insulation-in-the-middle type solar PCM storage wall (MSPCMW) system. The system has the following four independent functions, passive solar heating, heat preservation, heat insulation, and passive cooling, and it can agilely cope with the requirements of climatization of buildings in different seasons throughout the year and is exactly suitable for building in regions characterized by hot sum...

CVD-Based Valence-Mending Passivation for Crystalline-Si Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Tao, Meng [Arizona State Univ., Mesa, AZ (United States)

2015-03-01

The objective of this project is to investigate a new surface passivation technique, valence-mending passivation, for its applications in crystalline-Si solar cells to achieve significant efficiency improvement and cost reduction. As the enabling technique, the project includes the development of chemical vapor deposition recipes to passivate textured Si(100) and multicrystalline-Si surfaces by sulfur and the characterization of the passivated Si surfaces, including thermal stability, Schottky barrier height, contact resistance and surface recombination. One important application is to replace the Ag finger electrode in Si cells with Al to reduce cost, by ~$0.1/Wp, and allow terawatt-scale deployment of crystalline-Si solar cells. These all-Al Si cells require a low-temperature metallization process for the Al electrode, to be compatible with valence-mending passivation and to prevent Al diffusion into n-type Si. Another application is to explore valence-mending passivation of grain boundaries in multicrystalline Si by diffusing sulfur into grain boundaries, to reduce the efficiency gas between monocrystalline-Si solar cells and multicrystalline-Si cells. The major accomplishments of this project include: 1) Demonstration of chemical vapor deposition processes for valence-mending passivation of both monocrystalline Si(100) and multicrystalline Si surfaces. Record Schottky barriers have been demonstrated, with the new record-low barrier of less than 0.08 eV between Al and sulfur-passivated n-type Si(100) and the new record-high barrier of 1.14 eV between Al and sulfur-passivated p-type Si(100). On the textured p-type monocrystalline Si(100) surface, the highest barrier with Al is 0.85 eV by valence-mending passivation. 2) Demonstration of a low-temperature metallization process for Al in crystalline-Si solar cells. The new metallization process is based on electroplating of Al in a room-temperature ionic liquid. The resistivity of the electroplated Al is ~7×10–6

On the Modern History of Passive Solar Architecture

DEFF Research Database (Denmark)

Marsh, Rob

2017-01-01

This article examines the paradox of passive solar architecture within the Nordic context of Denmark, Norway and Sweden. Regulative developments to reduce space heating demand since the 1970s oil crisis are explored, highlighting architectural responses and the rise in prom-inence of passive solar...... design. An empirical study of passive solar housing schemes docu-ments architectural strategy, energy savings and extensive problems with overheating. A theo-retical study examines how passive solar was seen as advantageous when viewed with the 1985-2005 space heating paradigm, but actually resulted...... of Nordic modernism meant that passive solar architecture became the de-facto visual, aesthetic and functional expression of environmental design at that time. The article concludes by explor-ing the implications of the environmental paradigm for the architectural profession. By positing the architectural...

Protocol Monitoring Passive Solar Energy. Background document

International Nuclear Information System (INIS)

Van den Ham, E.R.

1998-01-01

A method has been developed by means of which the contribution of passive solar energy to the Dutch energy balance can be quantified univocally. The monitoring will be directed at the absolute amount of used solar energy, the relative contribution of passive solar energy to the energy demand in the Netherlands, and the average efficiency of passive solar energy systems. Based on a model of the total building stock the quantities to be monitored can be determined. The most important parameters in the model are: the window surface per orientation, the average U-value (heat transfer coefficient) of windows, the average ZTA-value (incoming solar radiation factor) of windows, and the presence of sun lounges and atriums

Solar '95: Proceedings of the 20. national passive solar conference. Volume 20

International Nuclear Information System (INIS)

Campbell-Howe, R.; Wilkins-Crowder, B.

1995-01-01

This book contains the proceedings of the 20th National Passive Solar Conference, 1995, of the American Solar Energy Society. The topics of the papers include historical aspects of solar energy, daylighting, examination of passive system designs, sustainability concepts, building components, building design, application of solar architecture, case studies, education, and design tools

Analytical optimization of interior PCM for energy storage in a lightweight passive solar room

International Nuclear Information System (INIS)

Xiao Wei; Wang Xin; Zhang Yinping

2009-01-01

Lightweight envelopes are widely used in modern buildings but they lack sufficient thermal capacity for passive solar utilization. An attractive solution to increase the building thermal capacity is to incorporate phase change material (PCM) into the building envelope. In this paper, a simplified theoretical model is established to optimize an interior PCM for energy storage in a lightweight passive solar room. Analytical equations are presented to calculate the optimal phase change temperature and the total amount of latent heat capacity and to estimate the benefit of the interior PCM for energy storage. Further, as an example, the analytical optimization is applied to the interior PCM panels in a direct-gain room with realistic outdoor climatic conditions of Beijing. The analytical results agree well with the numerical results. The analytical results show that: (1) the optimal phase change temperature depends on the average indoor air temperature and the radiation absorbed by the PCM panels; (2) the interior PCM has little effect on average indoor air temperature; and (3) the amplitude of the indoor air temperature fluctuation depends on the product of surface heat transfer coefficient h in and area A of the PCM panels in a lightweight passive solar room.

High performance passive solar heating system with heat pipe energy transfer and latent heat storage

NARCIS (Netherlands)

Dijk, van H.A.L.; Galen, van E; Hensen, J.L.M.; Wit, de M.H.

1983-01-01

Preliminar results are reported from a current project on the development of a high performance passive solar heating system. Two special components are introduced: a. A heat pipe as a thermal diode tube for the efficient transfer of collected solar heat from the absorber plate to behind an

Comprehensive Planning for Passive Solar Architectural Retrofit

Science.gov (United States)

1980-05-01

technical information, and the natural environ- ment. Since the Air Force Energy plan stresses Passive Solar (Architecture) before using Active Solar...retrofitted by-1990, and the Air Force Energy Plan stresses Passive Solar Applications. Bdcause of this requirement, you must consider the following retrofit...OF THI SUN AT NOON ON O CUMIN 21 EXAWMKU[ AT 3M. AN I S - W Figure 12-4 12-3 Skylight- use a reflector ,with horizontal skylights to ,iincrease solar

Protocol Monitoring Passive Solar Energy

International Nuclear Information System (INIS)

Van den Ham, E.R.; Bosselaar, L.

1998-01-01

A method has been developed by means of which the contribution of passive solar energy to the Dutch energy balance can be quantified univocally. The contribution was 57 PJ in 1990 and also 57 PJ in 1995. The efficiency of passive solar energy systems increased from -31.5% to -28.1% in the period 1990-1995, mainly as a result of the use of extra insulating glazing. As a result of the reduction of energy consumption for heating in houses it is expected that the extra contribution of 2 PJ will not be realized in the year 2010. It is suggested that the method to determine the absolute contribution of passive solar energy to the energy demand of dwellings is to be included in the protocol monitoring renewable energy. For the method to be included in the energy statistics of Statistics Netherlands (CBS) it can be considered only to take into account the difference compared to 1990. 11 refs

Performance of a desiccant assisted packed bed passive solar dryer for copra processing

Directory of Open Access Journals (Sweden)

Padmanaban Govindarajulu

2017-01-01

Full Text Available In this paper, the performance of a novel desiccant assisted packed bed passive solar dryer was evaluated for copra processing and compared with conventional passive solar dryer. This novel solar dryer consists of a desiccant assisted packed bed solar air heater attached with a dryer cabin. The desiccant and phase change materials packed in the solar air heater has control the humidity and retains the heat for longer duration, respectively. The performance of the dryer was evaluated (in terms of drying time to attain the final equilibrium moisture content, drying rate, specific moisture extraction rate, pick-up efficiency, and dryer efficiency under the meteorological conditions of Coimbatore city in India during March and April 2016. The copra was dried from initial moisture content (wet basis of about 52% to the final moisture content (wet basis of about 8% in 62 hours with specific moisture extraction rate of 0.82 kg/kWh. The drying time was reduced by about 44 hours when compared to the conventional passive solar dryer. The dryer pick-up efficiency was varied between about 10% and 65%. The average dryer thermal efficiency was calculated to be about 32%. The quality of final dried product was found to be good.

Passive solar offices: integrated design

Energy Technology Data Exchange (ETDEWEB)

Evans, B

1992-05-06

Passive solar design in out-of-town offices can remove the need for air-conditioning by making greater use of daylight and natural ventilation. To promote the use of passive solar energy a series of design studies are being run by the Energy Technology Support Unit on behalf of the Department of Energy. The three reported here are designs for out-of-town business buildings. Each is a hypothetical building designed to a realistic brief for an organisation taking the role of real client. (author).

Structural evolution of tunneling oxide passivating contact upon thermal annealing.

Science.gov (United States)

Choi, Sungjin; Min, Kwan Hong; Jeong, Myeong Sang; Lee, Jeong In; Kang, Min Gu; Song, Hee-Eun; Kang, Yoonmook; Lee, Hae-Seok; Kim, Donghwan; Kim, Ka-Hyun

2017-10-16

We report on the structural evolution of tunneling oxide passivating contact (TOPCon) for high efficient solar cells upon thermal annealing. The evolution of doped hydrogenated amorphous silicon (a-Si:H) into polycrystalline-silicon (poly-Si) by thermal annealing was accompanied with significant structural changes. Annealing at 600 °C for one minute introduced an increase in the implied open circuit voltage (V oc ) due to the hydrogen motion, but the implied V oc decreased again at 600 °C for five minutes. At annealing temperature above 800 °C, a-Si:H crystallized and formed poly-Si and thickness of tunneling oxide slightly decreased. The thickness of the interface tunneling oxide gradually decreased and the pinholes are formed through the tunneling oxide at a higher annealing temperature up to 1000 °C, which introduced the deteriorated carrier selectivity of the TOPCon structure. Our results indicate a correlation between the structural evolution of the TOPCon passivating contact and its passivation property at different stages of structural transition from the a-Si:H to the poly-Si as well as changes in the thickness profile of the tunneling oxide upon thermal annealing. Our result suggests that there is an optimum thickness of the tunneling oxide for passivating electron contact, in a range between 1.2 to 1.5 nm.

Demonstration of Passive Fuel Cell Thermal Management Technology

Science.gov (United States)

Burke, Kenneth A.; Jakupca, Ian; Colozza, Anthony; Wynne, Robert; Miller, Michael; Meyer, Al; Smith, William

2012-01-01

The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates and integrated heat exchanger technology to collect the heat from the cooling plates (Ref. 1). The next step in the development of this passive thermal approach was the demonstration of the control of the heat removal process and the demonstration of the passive thermal control technology in actual fuel cell stacks. Tests were run with a simulated fuel cell stack passive thermal management system outfitted with passive cooling plates, an integrated heat exchanger and two types of cooling flow control valves. The tests were run to demonstrate the controllability of the passive thermal control approach. Finally, successful demonstrations of passive thermal control technology were conducted with fuel cell stacks from two fuel cell stack vendors.

Passive solar energy information user study

Energy Technology Data Exchange (ETDEWEB)

Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

1980-11-01

The results of a series of telephone interviews with groups of users of information on passive solar heating and cooling are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from seven passive groups respondents are analyzed in this report: Federally Funded Researchers, Manufacturer Representatives, Architects, Builders, Educators, Cooperative Extension Service County Agents, and Homeowners. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

Photovoltaic. Solar thermal. Solar thermal electricity

International Nuclear Information System (INIS)

2009-01-01

The year 2008 was excellent for solar energy in the European Union. The growth of the installed capacity for photovoltaic was +159% (it means +4747.018 MW) to reach 9689.952 MW and that for solar thermal was +51.5% (it means +3172.5 MW) to reach 19982.7 MW. Worldwide concentrated solar thermal capacity stood at 679 MW in 2009, while this figure may seem low, the sector has a promising future ahead of it. (A.C.)

Compact, semi-passive beam steering prism array for solar concentrators.

Science.gov (United States)

Zheng, Cheng; Li, Qiyuan; Rosengarten, Gary; Hawkes, Evatt; Taylor, Robert A

2017-05-10

In order to maximize solar energy utilization in a limited space (e.g., rooftops), solar collectors should track the sun. As an alternative to rotational tracking systems, this paper presents a compact, semi-passive beam steering prism array which has been designed, analyzed, and tested for solar applications. The proposed prism array enables a linear concentrator system to remain stationary so that it can integrate with a variety of different solar concentrators, and which should be particularly useful for systems which require a low profile (namely rooftop-mounted systems). A case study of this prism array working within a specific rooftop solar collector demonstrates that it can boost the average daily optical efficiency of the collector by 32.7% and expand its effective working time from 6 h to 7.33 h. Overall, the proposed design provides an alternative way to "follow" the sun for a wide range of solar thermal and photovoltaic concentrator systems.

Field Measurement and Evaluation of the Passive and Active Solar Heating Systems for Residential Building Based on the Qinghai-Tibetan Plateau Case

Directory of Open Access Journals (Sweden)

Zhijian Liu

2017-10-01

Full Text Available Passive and active solar heating systems have drawn much attention and are widely used in residence buildings in the Qinghai-Tibetan plateau due to its high radiation intensity. In fact, there is still lack of quantitative evaluation of the passive and active heating effect, especially for residential building in the Qinghai-Tibetan plateau areas. In this study, three kinds of heating strategies, including reference condition, passive solar heating condition and active solar heating condition, were tested in one demonstration residential building. The hourly air temperatures of each room under different conditions were obtained and analyzed. The results show the indoor air temperature in the living room and bedrooms (core zones was much higher than that of other rooms under both passive and active solar heating conditions. In addition, the heating effect with different strategies for core zones of the building was evaluated by the ratio of indoor and outdoor degree hour, which indicates that solar heating could effectively reduce the traditional energy consumption and improve the indoor thermal environment. The passive solar heating could undertake 49.8% degree hours for heating under an evaluation criterion of 14 °C and the active solar heating could undertake 75% degree hours for heating under evaluation criterion of 18 °C, which indicated that solar heating could effectively reduce the traditional energy consumption and improve the indoor thermal environment in this area. These findings could provide reference for the design and application of solar heating in similar climate areas.

Wallboard with Latent Heat Storage for Passive Solar Applications; TOPICAL

International Nuclear Information System (INIS)

Kedl, R.J.

2001-01-01

Conventional wallboard impregnated with octadecane paraffin[melting point-23 C (73.5 F)] is being developed as a building material with latent heat storage for passive solar and other applications. Impregnation was accomplished simply by soaking the wallboard in molten wax. Concentrations of wax in the combined product as high as 35% by weight can be achieved. Scale-up of the soaking process, from small laboratory samples to full-sized 4- by 8-ft sheets, has been successfully accomplished. The required construction properties of wallboard are maintained after impregnation, that is, it can be painted and spackled. Long-term, high-temperature exposure tests and thermal cycling tests showed no tendency of the paraffin to migrate within the wallboard, and there was no deterioration of thermal energy storage capacity. In support of this concept, a computer model was developed to handle thermal transport and storage by a phase change material (PCM) dispersed in a porous media. The computer model was confirmed by comparison with known analytical solutions and also by comparison with temperatures measured in wallboard during an experimentally generated thermal transient. Agreement between the model and known solution was excellent. Agreement between the model and thermal transient was good, only after the model was modified to allow the PCM to melt over a temperature range, rather than at a specific melting point. When the melting characteristics of the PCM (melting point, melting range, and heat of fusion), as determined from a differential scanning calorimeter plot, were used in the model, agreement between the model and transient data was very good. The confirmed computer model may now be used in conjunction with a building heating and cooling code to evaluate design parameters and operational characteristics of latent heat storage wallboard for passive solar applications

Proceedings of the 18th national passive solar conference. Volume 18

International Nuclear Information System (INIS)

Burley, S.; Arden, M.E.

1993-01-01

The American Solar Energy Society conducts the National Solar Energy Conference as an annual forum for exchange of information about advances in solar energy technologies, programs, and concepts. The SOLAR 93 conference presented papers on the following topics: passive design tools; passive performance; building case studies; passive components, construction and glazing; daylighting; passive cooling; sustainability theory; sustainability projects; vernacular architecture; emerging architecture; and education. A total of forty-nine papers were indexed separately for the data base

Approach to interior design for passive direct gain solar homes

Energy Technology Data Exchange (ETDEWEB)

Kachadorian, C.C.

1980-01-01

In response to requests from buyers and builders of direct gain passive solar homes interior design criteria either specific to, or emphasized by, passive solar buildings are investigated. Problems of high sunlight penetration, secondary illumination, material selection, sound control and psychology are approached. Material deterioration, fading, glare, noise, and a sense of spacial confinement can be minimized, contributing to the appeal and saleability of passive solar homes.

Passivated emitters in silicon solar cells

International Nuclear Information System (INIS)

King, R.R.; Gruenbaum, P.E.; Sinton, R.A.; Swanson, R.M.

1990-01-01

In high-efficiency silicon solar cells with low metal contact coverage fractions and high bulk lifetimes, cell performance is often dominated by recombination in the oxide-passivated diffusions on the cell surface. Measurements of the emitter saturation current density, J o , of oxide-passivated, boron and phosphorus diffusions are presented, and from these measurements, the dependence of surface recombination velocity on dopant concentration was extracted. The lowest observed values of J o which are stable under UV light are given for both boron- and phosphorus-doped, oxide-passivated diffusions, for both textured and untextured surfaces. Contour plots which incorporate the above data have been applied to two types of backside-contact solar cells with large area (37.5 cm 2 ) and one-sun efficiencies up to 22.7%

Passive solar design strategies: Remodeling guidelines for conserving energy at home

Science.gov (United States)

The idea of passive solar is simple, but applying it effectively does require information and attention to the details of design and construction. Some passive solar techniques are modest and low-cost, and require only small changes in remodeler's typical practice. At the other end of the spectrum, some passive solar systems can almost eliminate a house's need for purchased heating (and in some cases, cooling) energy - but probably at a relatively high first cost. In between are a broad range of energy-conserving passive solar techniques. Whether or not they are cost-effective, practical, and attractive enough to offer a market advantage to any individual remodeler depends on very specific factors such as local costs, climate, and market characteristics. Passive Solar Design Strategies: Remodeling Guidelines For Conserving Energy At Home is written to help give remodelers the information they need to make these decisions. Passive Solar Design Strategies is a package in three basic parts: the guidelines contain information about passive solar techniques and how they work, and provides specific examples of systems which will save various percentages of energy; the worksheets offer a simple, fill-in-the-blank method to pre-evaluate the performance of a specific design; and the worked example demonstrates how to complete the worksheets for a typical residence.

Development of a solar thermal storage system suitable for the farmhouse heating in northeast China

Energy Technology Data Exchange (ETDEWEB)

Jang, M.K. [Shenyang Agricultural Univ., Shenyang (China)

2010-07-01

This study reported on the performance of a passive solar radiant floor heating system designed for standard energy-saving farmhouses in northeast China. Weather data in the region was analyzed in terms of solar radiation, temperature, humidity and light levels. The heating characteristics of the building materials such as windows, doors, walls and roofs were also analyzed along with the indoor thermal environment of the farmhouse. The heating load was then calculated along with the size of the thermal storage element and the area of the collector element. The passive solar radiant floor heating system was designed for heating during the winter and cooling in summer. According to the results, the heating characteristics of the system have the potential to improve farming villages environment and the use of renewable energy.

Solar Thermal Upper Stage Cryogen System Engineering Checkout Test

Science.gov (United States)

Olsen, A. D; Cady, E. C.; Jenkins, D. S.

1999-01-01

The Solar Thermal Upper Stage technology (STUSTD) program is a solar thermal propulsion technology program cooperatively sponsored by a Boeing led team and by NASA MSFC. A key element of its technology program is development of a liquid hydrogen (LH2) storage and supply system which employs multi-layer insulation, liquid acquisition devices, active and passive thermodynamic vent systems, and variable 40W tank heaters to reliably provide near constant pressure H2 to a solar thermal engine in the low-gravity of space operation. The LH2 storage and supply system is designed to operate as a passive, pressure fed supply system at a constant pressure of about 45 psia. During operation of the solar thermal engine over a small portion of the orbit the LH2 storage and supply system propulsively vents through the enjoy at a controlled flowrate. During the long coast portion of the orbit, the LH2 tank is locked up (unvented). Thus, all of the vented H2 flow is used in the engine for thrust and none is wastefully vented overboard. The key to managing the tank pressure and therefore the H2 flow to the engine is to manage and balance the energy flow into the LH2 tank with the MLI and tank heaters with the energy flow out of the LH2 tank through the vented H2 flow. A moderate scale (71 cu ft) LH2 storage and supply system was installed and insulated at the NASA MSFC Test Area 300. The operation of the system is described in this paper. The test program for the LH2 system consisted of two parts: 1) a series of engineering tests to characterize the performance of the various components in the system: and 2) a 30-day simulation of a complete LEO and GEO transfer mission. This paper describes the results of the engineering tests, and correlates these results with analytical models used to design future advanced Solar Orbit Transfer Vehicles.

Stable High-Performance Perovskite Solar Cells via Grain Boundary Passivation

KAUST Repository

Niu, Tianqi

2018-03-12

The trap states at grain boundaries (GBs) within polycrystalline perovskite films deteriorate their optoelectronic properties, making GB engineering particularly important for stable high-performance optoelectronic devices. It is demonstrated that trap states within bulk films can be effectively passivated by semiconducting molecules with Lewis acid or base functional groups. The perovskite crystallization kinetics are studied using in situ synchrotron-based grazing-incidence X-ray scattering to explore the film formation mechanism. A model of the passivation mechanism is proposed to understand how the molecules simultaneously passivate the Pb-I antisite defects and vacancies created by under-coordinated Pb atoms. In addition, it also explains how the energy offset between the semiconducting molecules and the perovskite influences trap states and intergrain carrier transport. The superior optoelectronic properties are attained by optimizing the molecular passivation treatments. These benefits are translated into significant enhancements of the power conversion efficiencies to 19.3%, as well as improved environmental and thermal stability of solar cells. The passivated devices without encapsulation degrade only by ≈13% after 40 d of exposure in 50% relative humidity at room temperature, and only ≈10% after 24 h at 80 °C in controlled environment.

Energy balance in a passive solar building. An attempt at economic assessment

Directory of Open Access Journals (Sweden)

Sobczyk Wiktoria

2016-01-01

Full Text Available The paper emphasizes possibilities for substantially reducing energy consumption with modern ecofriendly buildings. Passive building construction is a sector of the construction industry that has extremely low demand for the energy for heating house interiors. A passive house requires a small amount of energy to provide thermal comfort, but it requires proper systems (HRU, heat pumps, solar collectors to accomplish that effect. The modification proposal presented in the paper has dramatically reduced the demand for heat capacity of the building. Unfortunately the passive standard has not been reached, but thermomodernisation would allow for a significant reduction of heating costs. The demand per 1 m2 of heated surface area in a traditional building was 41.9 W/m2, while after the modification – only 15.01 W/m2. The tested building, if located in a warmer climate, with an average outside temperature of ≥ -10ºC would certainly perform its function. The use of modern technology ensures high energy savings. Such solutions, however, are not the cheapest on the market, and therefore are less available. The construction of a passive solar buildings is a “green” investment with tangible environmental results. By ensuring the thermomodernisation of a traditional building we can enjoy real environmental and economic benefits.

Solar thermal aircraft

Science.gov (United States)

Bennett, Charles L.

2007-09-18

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Advanced phase change materials and systems for solar passive heating and cooling of residential buildings

Energy Technology Data Exchange (ETDEWEB)

Salyer, I.O.; Sircar, A.K.; Dantiki, S.

1988-01-01

During the last three years under the sponsorship of the DOE Solar Passive Division, the University of Dayton Research Institute (UDRI) has investigated four phase change material (PCM) systems for utility in thermal energy storage for solar passive heating and cooling applications. From this research on the basis of cost, performance, containment, and environmental acceptability, we have selected as our current and most promising series of candidate phase change materials, C-15 to C-24 linear crystalline alkyl hydrocarbons. The major part of the research during this contract period was directed toward the following three objectives. Find, test, and develop low-cost effective phase change materials (PCM) that melt and freeze sharply in the comfort temperature range of 73--77{degree}F for use in solar passive heating and cooling of buildings. Define practical materials and processes for fire retarding plasterboard/PCM building products. Develop cost-effective methods for incorporating PCM into building construction materials (concrete, plasterboard, etc.) which will lead to the commercial manufacture and sale of PCM-containing products resulting in significant energy conservation.

Hydrogen passivation of polycrystalline Si thin film solar cells

International Nuclear Information System (INIS)

Gorka, Benjamin

2010-01-01

found for poly-Si with largest grains and coincides with best solar cell results, obtained after rapid thermal annealing and hydrogen passivation. Hydrogen passivation of poly-Si films was successfully achieved with a parallel plate rf H plasma treatment at elevated temperatures around 500 C to 600 C. Yet it seems that treatment induced defect generation causes a loss in V OC with prolonged passivation time and should be minimized. In order to achieve high open circuit voltages larger than 450 mV, in addition to hydrogen passivation, low recombination at the interfaces becomes more and more important. (orig.)

Passive solar design strategies: Remodeling guidelines for conserving energy at home

Energy Technology Data Exchange (ETDEWEB)

1991-01-01

The idea of passive solar is simple, but applying it effectively does require information and attention to the details of design and construction. Some passive solar techniques are modest and low-cost, and require only small changes in remodeler's typical practice. At the other end of the spectrum, some passive solar systems can almost eliminate a house's need for purchased heating (and in some cases, cooling) energy -- but probably at a relatively high first cost. In between are a broad range of energy-conserving passive solar techniques. Whether or not they are cost-effective, practical and attractive enough to offer a market advantage to any individual remodeler depends on very specific factors such as local costs, climate, and market characteristics. Passive solar design strategies: Remodeling Guidelines For Conserving Energy At Homes is written to help give remodelers the information they need to make these decisions. Passive Solar Design Strategies is a package in three basic parts: The Guidelines contain information about passive solar techniques and how they work, and provides specific examples of systems which will save various percentages of energy; The Worksheets offer a simple, fill-in-the-blank method to pre-evaluate the performance of a specific design; The Worked Example demonstrates how to complete the worksheets for a typical residence.

Surface Passivation for Silicon Heterojunction Solar Cells

NARCIS (Netherlands)

Deligiannis, D.

2017-01-01

Silicon heterojunction solar cells (SHJ) are currently one of the most promising solar cell technologies in the world. The SHJ solar cell is based on a crystalline silicon (c-Si) wafer, passivated on both sides with a thin intrinsic hydrogenated amorphous silicon (a-Si:H) layer. Subsequently, p-type

Solar thermal barometer

International Nuclear Information System (INIS)

Anon.

2004-01-01

After the bad year of 2002, the european solar thermal market returned to double-digit growth rate in 2003: 22%. Nevertheless, the sector still has not recovered the growth rate it had in the early 2000 and European Commission targets are still far from being reached. This paper presents the thermal solar industry barometer. Data on the evolution of annually installed surfaces in the european union since 1993, the cumulated capacity of thermal collectors installed in the European Union, the estimation of the annual energy production associated to european solar thermal capacities and the main companies of the European Union thermal solar sector are presented and discussed. (A.L.B.)

Efficiency improvement of multicrystalline silicon solar cells after surface and grain boundaries passivation using vanadium oxide

Energy Technology Data Exchange (ETDEWEB)

Derbali, L., E-mail: rayan.slat@yahoo.fr [Photovoltaiec Laboratory, Research and Technology Center of Energy, Technopole de Borj-Cedria, BP 95, Hammam-Lif 2050 (Tunisia); Ezzaouia, H. [Photovoltaiec Laboratory, Research and Technology Center of Energy, Technopole de Borj-Cedria, BP 95, Hammam-Lif 2050 (Tunisia)

2012-08-01

Highlights: Black-Right-Pointing-Pointer Evaporation of vanadium pentoxide onto the front surface leads to reduce the surface reflectivity considerably. Black-Right-Pointing-Pointer An efficient surface passivation can be obtained after thermal treatment of obtained films. Black-Right-Pointing-Pointer Efficiency of the obtained solar cells has been improved noticeably after thermal treatment of deposited thin films. - Abstract: The aim of this work is to investigate the effect of vanadium oxide deposition onto the front surface of multicrystalline silicon (mc-Si) substrat, without any additional cost in the fabrication process and leading to an efficient surface and grain boundaries (GBs) passivation that have not been reported before. The lowest reflectance of mc-Si coated with vanadium oxide film of 9% was achieved by annealing the deposited film at 600 Degree-Sign C. Vanadium pentoxide (V{sub 2}O{sub 5}) were thermally evaporated onto the surface of mc-Si substrates, followed by a short annealing duration at a temperature ranging between 600 Degree-Sign C and 800 Degree-Sign C, under O{sub 2} atmosphere. The chemical composition of the films was analyzed by means of Fourier transform infrared spectroscopy (FTIR). Surface and cross-section morphology were determined by atomic force microscope (AFM) and a scanning electron microscope (SEM), respectively. The deposited vanadium oxide thin films make the possibility of combining in one processing step an antireflection coating deposition along with efficient surface state passivation, as compared to a reference wafer. Silicon solar cells based on untreated and treated mc-Si wafers were achieved. We showed that mc-silicon solar cells, subjected to the above treatment, have better short circuit currents and open-circuit voltages than those made from untreated wafers. Thus, the efficiency of obtained solar cells has been improved.

Efficiency improvement of multicrystalline silicon solar cells after surface and grain boundaries passivation using vanadium oxide

International Nuclear Information System (INIS)

Derbali, L.; Ezzaouia, H.

2012-01-01

Highlights: ► Evaporation of vanadium pentoxide onto the front surface leads to reduce the surface reflectivity considerably. ► An efficient surface passivation can be obtained after thermal treatment of obtained films. ► Efficiency of the obtained solar cells has been improved noticeably after thermal treatment of deposited thin films. - Abstract: The aim of this work is to investigate the effect of vanadium oxide deposition onto the front surface of multicrystalline silicon (mc-Si) substrat, without any additional cost in the fabrication process and leading to an efficient surface and grain boundaries (GBs) passivation that have not been reported before. The lowest reflectance of mc-Si coated with vanadium oxide film of 9% was achieved by annealing the deposited film at 600 °C. Vanadium pentoxide (V 2 O 5 ) were thermally evaporated onto the surface of mc-Si substrates, followed by a short annealing duration at a temperature ranging between 600 °C and 800 °C, under O 2 atmosphere. The chemical composition of the films was analyzed by means of Fourier transform infrared spectroscopy (FTIR). Surface and cross-section morphology were determined by atomic force microscope (AFM) and a scanning electron microscope (SEM), respectively. The deposited vanadium oxide thin films make the possibility of combining in one processing step an antireflection coating deposition along with efficient surface state passivation, as compared to a reference wafer. Silicon solar cells based on untreated and treated mc-Si wafers were achieved. We showed that mc-silicon solar cells, subjected to the above treatment, have better short circuit currents and open-circuit voltages than those made from untreated wafers. Thus, the efficiency of obtained solar cells has been improved.

Solar Thermal Energy; Energia Solar Termica

Energy Technology Data Exchange (ETDEWEB)

Perez-Martinez, M; Cuesta-Santianes, M J; Cabrera Jimenez, J A

2008-07-01

Approximately, 50 % of worldwide primary energy consumption is done in the form of heat in applications with a temperature lower than 250 degree centigree (low-medium temperature heat). These data clearly demonstrate the great potential of solar thermal energy to substitute conventional fossil fuels, which are becoming more expensive and are responsible for global warming. Low-medium temperature solar thermal energy is mainly used to obtain domestic hot water and provide space heating. Active solar thermal systems are those related to the use of solar thermal collectors. This study is dealing with low temperature solar thermal applications, mainly focusing on active solar thermal systems. This kind of systems has been extensively growing worldwide during the last years. At the end of 2006, the collector capacity in operation worldwide equalled 127.8 GWth. The technology is considered to be already developed and actions should be aimed at favouring a greater market penetration: diffusion, financial support, regulations establishment, etc. China and USA are the leading countries with a technology based on evacuated tube collectors and unglazed collectors, respectively. The rest of the world markets are dominated by the flat glazed collectors technology. (Author) 15 refs.

Thermal performance of evacuated tube heat pipe solar collector

Science.gov (United States)

Putra, Nandy; Kristian, M. R.; David, R.; Haliansyah, K.; Ariantara, Bambang

2016-06-01

The high fossil energy consumption not only causes the scarcity of energy but also raises problems of global warming. Increasing needs of fossil fuel could be reduced through the utilization of solar energy by using solar collectors. Indonesia has the abundant potential for solar energy, but non-renewable energy sources still dominate energy consumption. With heat pipe as passive heat transfer device, evacuated tube solar collector is expected to heat up water for industrial and home usage without external power supply needed to circulate water inside the solar collector. This research was conducted to determine the performance of heat pipe-based evacuated tube solar collector as solar water heater experimentally. The experiments were carried out using stainless steel screen mesh as a wick material, and water and Al2O3-water 0.1% nanofluid as working fluid, and applying inclination angles of 0°, 15°, 30°, and 45°. To analyze the heat absorbed and transferred by the prototype, water at 30°C was circulated through the condenser. A 150 Watt halogen lamp was used as sun simulator, and the prototype was covered by an insulation box to obtain a steady state condition with a minimum affection of ambient changes. Experimental results show that the usage of Al2O3-water 0.1% nanofluid at 30° inclination angle provides the highest thermal performance, which gives efficiency as high as 0.196 and thermal resistance as low as 5.32 °C/W. The use of nanofluid as working fluid enhances thermal performance due to high thermal conductivity of the working fluid. The increase of the inclination angle plays a role in the drainage of the condensate to the evaporator that leads to higher thermal performance until the optimal inclination angle is reached.

Stable High-Performance Perovskite Solar Cells via Grain Boundary Passivation.

Science.gov (United States)

Niu, Tianqi; Lu, Jing; Munir, Rahim; Li, Jianbo; Barrit, Dounya; Zhang, Xu; Hu, Hanlin; Yang, Zhou; Amassian, Aram; Zhao, Kui; Liu, Shengzhong Frank

2018-04-01

The trap states at grain boundaries (GBs) within polycrystalline perovskite films deteriorate their optoelectronic properties, making GB engineering particularly important for stable high-performance optoelectronic devices. It is demonstrated that trap states within bulk films can be effectively passivated by semiconducting molecules with Lewis acid or base functional groups. The perovskite crystallization kinetics are studied using in situ synchrotron-based grazing-incidence X-ray scattering to explore the film formation mechanism. A model of the passivation mechanism is proposed to understand how the molecules simultaneously passivate the Pb-I antisite defects and vacancies created by under-coordinated Pb atoms. In addition, it also explains how the energy offset between the semiconducting molecules and the perovskite influences trap states and intergrain carrier transport. The superior optoelectronic properties are attained by optimizing the molecular passivation treatments. These benefits are translated into significant enhancements of the power conversion efficiencies to 19.3%, as well as improved environmental and thermal stability of solar cells. The passivated devices without encapsulation degrade only by ≈13% after 40 d of exposure in 50% relative humidity at room temperature, and only ≈10% after 24 h at 80 °C in controlled environment. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carrier population control and surface passivation in solar cells

KAUST Repository

Cuevas, Andres

2018-05-02

Controlling the concentration of charge carriers near the surface is essential for solar cells. It permits to form regions with selective conductivity for either electrons or holes and it also helps to reduce the rate at which they recombine. Chemical passivation of the surfaces is equally important, and it can be combined with population control to implement carrier-selective, passivating contacts for solar cells. This paper discusses different approaches to suppress surface recombination and to manipulate the concentration of carriers by means of doping, work function and charge. It also describes some of the many surface-passivating contacts that are being developed for silicon solar cells, restricted to experiments performed by the authors.

Hydrogen passivation of polycrystalline Si thin film solar cells

Energy Technology Data Exchange (ETDEWEB)

Gorka, Benjamin

2010-12-15

of 2.5.10{sup 16} cm{sup -3} after passivation was found for poly-Si with largest grains and coincides with best solar cell results, obtained after rapid thermal annealing and hydrogen passivation. Hydrogen passivation of poly-Si films was successfully achieved with a parallel plate rf H plasma treatment at elevated temperatures around 500 C to 600 C. Yet it seems that treatment induced defect generation causes a loss in V{sub OC} with prolonged passivation time and should be minimized. In order to achieve high open circuit voltages larger than 450 mV, in addition to hydrogen passivation, low recombination at the interfaces becomes more and more important. (orig.)

Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

Science.gov (United States)

Longe, Karen M.; McClelland, Michael J.

Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

Hybrid Solar: A Review on Photovoltaic and Thermal Power Integration

Directory of Open Access Journals (Sweden)

T. T. Chow

2012-01-01

Full Text Available The market of solar thermal and photovoltaic electricity generation is growing rapidly. New ideas on hybrid solar technology evolve for a wide range of applications, such as in buildings, processing plants, and agriculture. In the building sector in particular, the limited building space for the accommodation of solar devices has driven a demand on the use of hybrid solar technology for the multigeneration of active power and/or passive solar devices. The importance is escalating with the worldwide trend on the development of low-carbon/zero-energy buildings. Hybrid photovoltaic/thermal (PVT collector systems had been studied theoretically, numerically, and experimentally in depth in the past decades. Together with alternative means, a range of innovative products and systems has been put forward. The final success of the integrative technologies relies on the coexistence of robust product design/construction and reliable system operation/maintenance in the long run to satisfy the user needs. This paper gives a broad review on the published academic works, with an emphasis placed on the research and development activities in the last decade.

Nanolayer surface passivation schemes for silicon solar cells

NARCIS (Netherlands)

Dingemans, G.

2011-01-01

This thesis is concerned with nanolayer surface passivation schemes and corresponding deposition processes, for envisaged applications in crystalline silicon solar cells. Surface passivation, i.e. the reduction of electronic recombination processes at semiconductor surfaces, is essential for

Hydrogen passivation of multi-crystalline silicon solar cells

Institute of Scientific and Technical Information of China (English)

胡志华; 廖显伯; 刘祖明; 夏朝凤; 陈庭金

2003-01-01

The effects of hydrogen passivation on multi-crystalline silicon (mc-Si) solar cells are reported in this paper.Hydrogen plasma was generated by means of ac glow discharge in a hydrogen atmosphere. Hydrogen passivation was carried out with three different groups of mc-Si solar cells after finishing contacts. The experimental results demonstrated that the photovoltaic performances of the solar cell samples have been improved after hydrogen plasma treatment, with a relative increase in conversion efficiency up to 10.6%. A calculation modelling has been performed to interpret the experimental results using the model for analysis of microelectronic and photonic structures developed at Pennsylvania State University.

PECVD-ONO: A New Deposited Firing Stable Rear Surface Passivation Layer System for Crystalline Silicon Solar Cells

Directory of Open Access Journals (Sweden)

M. Hofmann

2008-01-01

Full Text Available A novel plasma-enhanced chemical vapour deposited (PECVD stack layer system consisting of a-SiOx:H, a-SiNx:H, and a-SiOx:H is presented for silicon solar cell rear side passivation. Surface recombination velocities below 60 cm/s (after firing and below 30 cm/s (after forming gas anneal were achieved. Solar cell precursors without front and rear metallisation showed implied open-circuit voltages Voc values extracted from quasi-steady-state photoconductance (QSSPC measurements above 680 mV. Fully finished solar cells with up to 20.0% energy conversion efficiency are presented. A fit of the cell's internal quantum efficiency using software tool PC1D and a comparison to a full-area aluminium-back surface field (Al-BSF and thermal SiO2 is shown. PECVD-ONO was found to be clearly superior to Al-BSF. A separation of recombination at the metallised and the passivated area at the solar cell's rear is presented using the equations of Fischer and Kray. Nuclear reaction analysis (NRA has been used to evaluate the hydrogen depth profile of the passivation layer system at different stages.

Phase-change drywalls in a passive-solar building

Energy Technology Data Exchange (ETDEWEB)

Darkwa, K.; O' Callaghan, P.W.; Tetlow, D. [School of the Built Environment, The Applied Energy and Environmental Engineering Group, Nottingham Trent University, Burton Street, Nottingham NG1 4BU (United Kingdom)

2006-05-15

Integration of phase-change materials (PCMs) into building fabrics is considered to be one of the potential and effective ways of minimising energy-consumption and CO{sub 2}-emissions in the building sector. In order to assess the thermal effectiveness of this concept, composite PCM drywall samples (i.e., randomly mixed and laminated PCM drywalls) have been evaluated in a model passive-solar building. For a broader assessment, the effects of three phase-change zones (narrow, intermediate and wide) of the PCM sample were considered. The results showed that the laminated PCM sample with a narrow phase-change zone was capable of increasing the minimum room temperature by about 17% more than the randomly mixed type. Even though there was some display of a non-isothermal phase-change process, the laminated system proved to be thermally more effective in terms of evolution and utilisation of latent heat. A further heat-transfer enhancement process is, however, required for the development of the laminated system. . (author)

Passive solar design strategies: Remodeling guidelines for conserving energy at home. [Final report

Energy Technology Data Exchange (ETDEWEB)

1991-12-31

The idea of passive solar is simple, but applying it effectively does require information and attention to the details of design and construction. Some passive solar techniques are modest and low-cost, and require only small changes in remodeler`s typical practice. At the other end of the spectrum, some passive solar systems can almost eliminate a house`s need for purchased heating (and in some cases, cooling) energy -- but probably at a relatively high first cost. In between are a broad range of energy-conserving passive solar techniques. Whether or not they are cost-effective, practical and attractive enough to offer a market advantage to any individual remodeler depends on very specific factors such as local costs, climate, and market characteristics. Passive solar design strategies: Remodeling Guidelines For Conserving Energy At Homes is written to help give remodelers the information they need to make these decisions. Passive Solar Design Strategies is a package in three basic parts: The Guidelines contain information about passive solar techniques and how they work, and provides specific examples of systems which will save various percentages of energy; The Worksheets offer a simple, fill-in-the-blank method to pre-evaluate the performance of a specific design; The Worked Example demonstrates how to complete the worksheets for a typical residence.

Significantly enhanced thermal conductivity of indium arsenide nanowires via sulfur passivation.

Science.gov (United States)

Xiong, Yucheng; Tang, Hao; Wang, Xiaomeng; Zhao, Yang; Fu, Qiang; Yang, Juekuan; Xu, Dongyan

2017-10-16

In this work, we experimentally investigated the effect of sulfur passivation on thermal transport in indium arsenide (InAs) nanowires. Our measurement results show that thermal conductivity can be enhanced by a ratio up to 159% by sulfur passivation. Current-voltage (I-V) measurements were performed on both unpassivated and S-passivated InAs nanowires to understand the mechanism of thermal conductivity enhancement. We observed a remarkable improvement in electrical conductivity upon sulfur passivation and a significant contribution of electrons to thermal conductivity, which account for the enhanced thermal conductivity of the S-passivated InAs nanowires.

Design of an atrium for a passive-solar retrofit of an office buildings

Energy Technology Data Exchange (ETDEWEB)

Peterson, J.L.; Hunn, B.D.

1980-01-01

The Los Alamos Scientific Laboratory (LASL) has proposed to retrofit one of its administrative office buildings with a solar atrium. A 334 m/sup 2/ courtyard will be enclosed with a roof-mounted system of clerestory windows to maximize winter solar gain. This sunspace will thermally buffer the adjoining offices and also will preheat air supplied to the building's conventional heating, ventilating, and air-conditioning (HVAC) system. The use of the DOE-2 building energy analysis computer program in the design of the solar atrium is described. The results of a series of simulations are reported detailing the tradeoffs inherent in the selection of an optimal glazing area, the maintenance of acceptable comfort levels within the sunspace, and intergration of passive-solar devices with the conventional HVAC system. Potential energy savings are also discussed.

Solar thermal

International Nuclear Information System (INIS)

Jones, J.

2006-01-01

While wind power is widely acknowledged as the most developed of the 'new' renewables, the number two technology, in terms of installed capacity functioning worldwide, is solar heating, or solar thermal. The author has investigated recent industry reports on how these markets are developing. The authors of an International Energy Agency (IEA) survey studied 41 countries in depth at the end of 2004, revealing that 141 million m 3 - corresponding to an installed capacity of 98.4 GWth - were installed in the sample countries (these nations represent 3.74 billion people, about 57% of the world's population). The installed capacity within the areas studied represents approximately 85%-90% of the solar thermal market worldwide. The use of solar heating varies greatly between countries - even close neighbours - and between economic regions. Its uptake often has more to do with policy than solar resource. There is also different uptake of technology. In China, Europe and Japan, plants with flat-plate and evacuated tube collectors are used, mainly to heat water and for space heating. Unglazed plastic collectors, used mainly for swimming pool heating, meanwhile, dominate the North American markets. Though the majority of solar heating installations today are installed on domestic rooftops, the larger-scale installations should not be overlooked. One important part of the market is the hotel sector - in particular hotels in locations that serve the seasonal summer holiday market, where solar is extremely effective. Likewise hospitals and residential homes, multi-family apartment blocks and sports centres are all good examples of places where solar thermal can deliver results. There are also a growing number of industrial applications, where solar thermal can meet the hot water needs (and possibly more) of a range of industries, such as food processing and agriculture. The ability of solar to provide a heat source for cooling is expected to become increasingly important as

Solar thermal

Energy Technology Data Exchange (ETDEWEB)

Jones, J.

2006-07-15

While wind power is widely acknowledged as the most developed of the 'new' renewables, the number two technology, in terms of installed capacity functioning worldwide, is solar heating, or solar thermal. The author has investigated recent industry reports on how these markets are developing. The authors of an International Energy Agency (IEA) survey studied 41 countries in depth at the end of 2004, revealing that 141 million m{sup 3} - corresponding to an installed capacity of 98.4 GWth - were installed in the sample countries (these nations represent 3.74 billion people, about 57% of the world's population). The installed capacity within the areas studied represents approximately 85%-90% of the solar thermal market worldwide. The use of solar heating varies greatly between countries - even close neighbours - and between economic regions. Its uptake often has more to do with policy than solar resource. There is also different uptake of technology. In China, Europe and Japan, plants with flat-plate and evacuated tube collectors are used, mainly to heat water and for space heating. Unglazed plastic collectors, used mainly for swimming pool heating, meanwhile, dominate the North American markets. Though the majority of solar heating installations today are installed on domestic rooftops, the larger-scale installations should not be overlooked. One important part of the market is the hotel sector - in particular hotels in locations that serve the seasonal summer holiday market, where solar is extremely effective. Likewise hospitals and residential homes, multi-family apartment blocks and sports centres are all good examples of places where solar thermal can deliver results. There are also a growing number of industrial applications, where solar thermal can meet the hot water needs (and possibly more) of a range of industries, such as food processing and agriculture. The ability of solar to provide a heat source for cooling is expected to become

Excellent c-Si surface passivation by thermal atomic layer deposited aluminum oxide after industrial firing activation

International Nuclear Information System (INIS)

Liao, B; Stangl, R; Ma, F; Mueller, T; Lin, F; Aberle, A G; Bhatia, C S; Hoex, B

2013-01-01

We demonstrate that by using a water (H 2 O)-based thermal atomic layer deposited (ALD) aluminum oxide (Al 2 O 3 ) film, excellent surface passivation can be attained on planar low-resistivity silicon wafers. Effective carrier lifetime values of up to 12 ms and surface recombination velocities as low as 0.33 cm s −1 are achieved on float-zone wafers after a post-deposition thermal activation of the Al 2 O 3 passivation layer. This post-deposition activation is achieved using an industrial high-temperature firing process which is commonly used for contact formation of standard screen-printed silicon solar cells. Neither a low-temperature post-deposition anneal nor a silicon nitride capping layer is required in this case. Deposition temperatures in the 100–400 °C range and peak firing temperatures of about 800 °C (set temperature) are investigated. Photoluminescence imaging shows that the surface passivation is laterally uniform. Corona charging and capacitance–voltage measurements reveal that the negative fixed charge density near the AlO x /c-Si interface increases from 1.4 × 10 12 to 3.3 × 10 12 cm −2 due to firing, while the midgap interface defect density reduces from 3.3 × 10 11 to 0.8 × 10 11 cm −2 eV −1 . This work demonstrates that direct firing activation of thermal ALD Al 2 O 3 is feasible, which could be beneficial for solar cell manufacturing. (paper)

Effect of openings collectors and solar irradiance on the thermal efficiency of flat plate-finned collector for indirect-type passive solar dryer

Science.gov (United States)

Batubara, Fatimah; Dina, Sari Farah; Klaudia Kathryn Y., M.; Turmuzi, M.; Siregar, Fitri; Panjaitan, Nora

2017-06-01

Research on the effect of openings solar collector and solar irradiance to thermal efficiency has been done. Solar collector by flat plate-finned type consists of 3 ply insulator namely wood, Styrofoam and Rockwool with thickness respectively are 10 mm, 25 mm and 50 mm. Absorber plate made of aluminum sheet with thickness of 0.30 mm, painted by black-doff. Installation of 19 units fins (length x height x thickness: 1000x20x10 mm) on the collector will increase surface area of absorber so it can receive much more solar energy. The solar collector cover is made of glass (thickness of 5 mm). During the research, the solar irradiance and temperature of collector are measured and recorded every five minutes. Temperature measurement performed on the surface of the absorber plate, inside of collector, surface cover and the outer side insulator (plywood). This data is used to calculate the heat loss due to conduction, convection and radiation on the collector. Openings of collectors vary as follows: 100%, 75%, 15% and 0% (total enclosed). The data collecting was conducted from 09.00 am to 17.00 pm and triplicates. The collector thermal efficiency calculated based on the ratio of the amount of heat received to the solar irradiance absorbed. The results show that each of openings solar collector has different solar irradiance (because it was done on a different day) which is in units of W/m2: 390 (100% open), 376 (75% open), 429 (15% open), and 359 (totally enclosed). The highest thermal efficiency is in openings variation of 15% opened. These results indicate that the efficiency of the collector is influenced by the solar irradiance received by the collector and the temperature on the collector plate. The highest thermal efficiency is in variation of openings 15%. These indicate that the efficiency of the collector was influenced by solar irradiance received by the collector and openings of the collector plate.

Energy savings solutions: passive solar design in Iranian cold climate

Energy Technology Data Exchange (ETDEWEB)

Nassehzadeh Tabriz, Shahram [Department of Architecture, Miyaneh Branch, Islamic Azad University (Iran, Islamic Republic of)], email: sh_nassehzadeh@m-iau.ac.ir; Mahdavi Tabatabaei Fard, Fariborz [SABAT TARH CO. (Iran, Islamic Republic of)], email: sabat_arc@yahoo.com; Aliyev, Fagan [International Eco-energy Academy (Azerbaijan)], email: ie_academy@yahoo.com

2011-07-01

In recent years, there has been a significant increase in the cost of fuel gas, fuel oil and electricity and much thought has been given to the use of solar energy. Living in a solar heated house gives peace of mind and body and it makes good sense in mountainous regions. Severe winters in such regions make more energy for standard living activities in buildings necessary. This paper discusses passive solar building design as an energy saving solution. In this type of design, windows, walls and floors act as storage and distribution devices for solar energy in winter and deflect solar heat in summer. Passive solar design techniques influence the choice of building site, design and materials within the general framework of enriching the quality of life of the inhabitants. As a result, natural resources are saved and the environment is conserved for future generations. In conclusion, it is seen that passive design keeps a home cool and comfortable in summer and warm and cozy in winter with minimal heating and cooling requirements.

Thermal solar energy

International Nuclear Information System (INIS)

Gonzalez, J.C.; Leal C, H.

1998-01-01

Some relative aspects to the development and current state of thermal solar energy are summarized, so much at domestic level as international. To facilitate the criteria understanding as the size of the facilities in thermal solar systems, topics as availability of the solar resource and its interactions with the matter are included. Finally, some perspectives for the development of this energetic alternative are presented

Enhancing Stability of Perovskite Solar Cells to Moisture by the Facile Hydrophobic Passivation.

Science.gov (United States)

Hwang, Insung; Jeong, Inyoung; Lee, Jinwoo; Ko, Min Jae; Yong, Kijung

2015-08-12

In this study, a novel and facile passivation process for a perovskite solar cell is reported. Poor stability in ambient atmosphere, which is the most critical demerit of a perovskite solar cell, is overcome by a simple passivation process using a hydrophobic polymer layer. Teflon, the hydrophobic polymer, is deposited on the top of a perovskite solar cell by a spin-coating method. With the hydrophobic passivation, the perovskite solar cell shows negligible degradation after a 30 day storage in ambient atmosphere. Suppressed degradation of the perovskite film is proved in various ways: X-ray diffraction, light absorption spectrum, and quartz crystal microbalance. This simple but effective passivation process suggests new kind of approach to enhance stability of perovskite solar cells to moisture.

Photovoltaic Thermal panels in collective thermal solar systems

International Nuclear Information System (INIS)

Elswijk, M.J.; Strootman, K.J.; Jong, M.J.M.; De Lange, E.T.N.; Smit, W.F.

2003-12-01

A feasibility study has been carried out to assess the options to apply photovoltaic/thermal panels (PVT-panels) in collective solar thermal systems in urban areas in the Netherlands. The study was focused on the technical (architecture and installations) and the economical feasibility of collective PVT-systems in comparison with conventional solar thermal systems and combinations of photovoltaic (PV) panels and solar collectors. The results of the study also give insight into cost and the market for PVT-panels. Three case studies in which collective solar collector systems were applied are analyzed again by simulating the installation of a PVT-panels system and a separate solar thermal PV system [nl

Solar thermal utilization--an overview

International Nuclear Information System (INIS)

Chen Deming; Xu Gang

2007-01-01

Solar energy is an ideal renewable energy source and its thermal utilization is one of its most important applications. We review the status of solar thermal utilization, including: (1) developed technologies which are already widely used all over the world, such as solar assisted water heaters, solar cookers, solar heated buildings and so on; (2) advanced technologies which are still in the development or laboratory stage and could have more innovative applications, including thermal power generation, refrigeration, hydrogen production, desalination, and chimneys; (3) major problems which need to be resolved for advanced utilizaiton of solar thermal energy. (authors)

Energy Conservation and Passive Solar Techniques in Campus Renovation.

Science.gov (United States)

Probasco, Jack; And Others

1981-01-01

The analysis of a building from an energy conservation and passive solar potential has three aspects: building envelope, landscaping, and room utilization. Typical conservation and solar control modifications are listed. (Author/MLF)

Optically Transparent Thermally Insulating Silica Aerogels for Solar Thermal Insulation.

Science.gov (United States)

Günay, A Alperen; Kim, Hannah; Nagarajan, Naveen; Lopez, Mateusz; Kantharaj, Rajath; Alsaati, Albraa; Marconnet, Amy; Lenert, Andrej; Miljkovic, Nenad

2018-04-18

Rooftop solar thermal collectors have the potential to meet residential heating demands if deployed efficiently at low solar irradiance (i.e., 1 sun). The efficiency of solar thermal collectors depends on their ability to absorb incoming solar energy and minimize thermal losses. Most techniques utilize a vacuum gap between the solar absorber and the surroundings to eliminate conduction and convection losses, in combination with surface coatings to minimize reradiation losses. Here, we present an alternative approach that operates at atmospheric pressure with simple, black, absorbing surfaces. Silica based aerogels coated on black surfaces have the potential to act as simple and inexpensive solar thermal collectors because of their high transmission to solar radiation and low transmission to thermal radiation. To demonstrate their heat-trapping properties, we fabricated tetramethyl orthosilicate-based silica aerogels. A hydrophilic aerogel with a thickness of 1 cm exhibited a solar-averaged transmission of 76% and thermally averaged transmission of ≈1% (at 100 °C). To minimize unwanted solar absorption by O-H groups, we functionalized the aerogel to be hydrophobic, resulting in a solar-averaged transmission of 88%. To provide a deeper understanding of the link between aerogel properties and overall efficiency, we developed a coupled radiative-conductive heat transfer model and used it to predict solar thermal performance. Instantaneous solar thermal efficiencies approaching 55% at 1 sun and 80 °C were predicted. This study sheds light on the applicability of silica aerogels on black coatings for solar thermal collectors and offers design priorities for next-generation solar thermal aerogels.

Solar passive buildings for developing countries

International Nuclear Information System (INIS)

Gupta, C.L.

1993-01-01

This paper is meant to be an indicative survey of developments in solar passive building technology relevant to developing countries. The evolution of this area during the last fifty years is reported along with the scientific principles and design concepts underlying these developments. Factors to be considered for design strategies such as direct gain, isolated gain, indirect gain and roof evaporative systems are then described. Rating parameters for assessing the performance and benefit and cost parameters are then outlined. Successful examples illustrating each of the design concepts, mainly from Indian buildings constructed during the last fifteen years, are then detailed along with their performance based on actual monitoring, if available. Concluding remarks indicate the current and future trends. A survey is made of papers marking significant milestones in the development of solar passive building technology relevant to developing countries. (author). 48 refs., 14 figs., 3 tabs

Two or three decades of passive directions

International Nuclear Information System (INIS)

Cook, J.

1995-01-01

This paper presents an overview of the direction of passive solar architecture. The topics of the paper include design temperatures for buildings, active vs passive, fuel vs philosophy, engineering vs architecture, the thermal scale: heating vs cooling, fuel subsidies, divergent practices, sustainability, lighting, health, the place of passive technology

Passive solar homes in Michigan's Upper Peninsula

Energy Technology Data Exchange (ETDEWEB)

Kindred, G.F. [Garfield Kindred Associates, Hancock, MI (United States)

2001-07-01

This paper discussed the construction and design of 3 affordable passive solar homes located in high latitudes: (1) the Kindred house located in a wooded subdivision in Hancock, Michigan; (2) the Autio house located in Laurium, Michigan; and the Mikkola house located in South Range, Michigan. The award-winning houses were part of the United States federal government's Energy Star program. The houses were constructed with common building materials in order to introduce the general public to the principles of energy-conscious passive solar design strategies and sustainable construction technologies. Super-insulation was used to retain solar heat gain in the houses. Air infiltration was minimized through the use of an airtight drywall sealing technique. Large windows were a prominent feature of the southern facades of the houses. The windows used fixed and casement low-e argon-filled insulated glazing. Average bills for the Kindred home are US$960 per year. It was concluded that passive solar design and construction strategies are now being used more often in the area as a result of the positive media coverage that the homes has received. 5 refs.

Advanced diffusion system for low contamination in-line rapid thermal processing of silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Biro, D.; Preu, R.; Schultz, O.; Peters, S.; Huljic, D.M.; Zickermann, D.; Schindler, R.; Luedemann, R.; Willeke, G. [Fraunhofer Institute for Solar Energy Systems ISE, Freiburg (Germany)

2002-10-01

A novel diffusion system for in-line rapid thermal diffusion is presented. The lamp-heated furnace has a low thermal mass and a metal free transport system based on the walking beam principle. The furnace has been used to process first solar cells with lightly and highly doped emitters respectively. Solar cells with shallow lightly doped emitters show that the emitters processed in the new device can be well passivated. Shallow emitters with sheet resistances of up to 40/sq. have been contacted successfully by means of screen printing and firing through a SiN{sub x} antireflection coating. (author)

Solar thermal - the new dynamics

International Nuclear Information System (INIS)

2017-01-01

This booklet is intended to engineering consultants and construction professionals and aims at showing them the real interest of solar thermal energy. It notably highlights the very high efficiency which can be reached, the high performance value compared to gas, the high rank of solar thermal energy in terms of profitability over a 20-year period, the fact that solar thermal energy is almost always the most economic solution for buildings and the less expensive in comparison with non renewable energies. It outlines that, as far as purchase is concerned, solar thermal energy is more than competitive, is also a leader as far as financing issues are concerned. It finally briefly describes how the SOCOL initiative can be a support at any step of a solar thermal project

More Efficient Solar Thermal-Energy Receiver

Science.gov (United States)

Dustin, M. O.

1987-01-01

Thermal stresses and reradiation reduced. Improved design for solar thermal-energy receiver overcomes three major deficiencies of solar dynamic receivers described in literature. Concentrator and receiver part of solar-thermal-energy system. Receiver divided into radiation section and storage section. Concentrated solar radiation falls on boiling ends of heat pipes, which transmit heat to thermal-energy-storage medium. Receiver used in number of applications to produce thermal energy directly for use or to store thermal energy for subsequent use in heat engine.

Molecular Monolayers for Electrical Passivation and Functionalization of Silicon-Based Solar Energy Devices.

Science.gov (United States)

Veerbeek, Janneke; Firet, Nienke J; Vijselaar, Wouter; Elbersen, Rick; Gardeniers, Han; Huskens, Jurriaan

2017-01-11

Silicon-based solar fuel devices require passivation for optimal performance yet at the same time need functionalization with (photo)catalysts for efficient solar fuel production. Here, we use molecular monolayers to enable electrical passivation and simultaneous functionalization of silicon-based solar cells. Organic monolayers were coupled to silicon surfaces by hydrosilylation in order to avoid an insulating silicon oxide layer at the surface. Monolayers of 1-tetradecyne were shown to passivate silicon micropillar-based solar cells with radial junctions, by which the efficiency increased from 8.7% to 9.9% for n + /p junctions and from 7.8% to 8.8% for p + /n junctions. This electrical passivation of the surface, most likely by removal of dangling bonds, is reflected in a higher shunt resistance in the J-V measurements. Monolayers of 1,8-nonadiyne were still reactive for click chemistry with a model catalyst, thus enabling simultaneous passivation and future catalyst coupling.

Development of Passive Fuel Cell Thermal Management Heat Exchanger

Science.gov (United States)

Burke, Kenneth A.; Jakupca, Ian J.; Colozza, Anthony J.

2010-01-01

The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates that could conduct the heat, provide a sufficiently uniform temperature heat sink for each cell of the fuel cell stack, and be substantially lighter than the conventional thermal management approach. Tests were run with different materials to evaluate the design approach to a heat exchanger that could interface with the edges of the passive cooling plates. Measurements were made during fuel cell operation to determine the temperature of individual cooling plates and also to determine the temperature uniformity from one cooling plate to another.

Passivation Using Molecular Halides Increases Quantum Dot Solar Cell Performance.

Science.gov (United States)

Lan, Xinzheng; Voznyy, Oleksandr; Kiani, Amirreza; García de Arquer, F Pelayo; Abbas, Abdullah Saud; Kim, Gi-Hwan; Liu, Mengxia; Yang, Zhenyu; Walters, Grant; Xu, Jixian; Yuan, Mingjian; Ning, Zhijun; Fan, Fengjia; Kanjanaboos, Pongsakorn; Kramer, Illan; Zhitomirsky, David; Lee, Philip; Perelgut, Alexander; Hoogland, Sjoerd; Sargent, Edward H

2016-01-13

A solution-based passivation scheme is developed featuring the use of molecular iodine and PbS colloidal quantum dots (CQDs). The improved passivation translates into a longer carrier diffusion length in the solid film. This allows thicker solar-cell devices to be built while preserving efficient charge collection, leading to a certified power conversion efficiency of 9.9%, which is a new record in CQD solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solar Thermal | Climate Neutral Research Campuses | NREL

Science.gov (United States)

building can still be designed and constructed to be solar ready with roof exposures and slopes that accept Solar Thermal Solar Thermal Solar thermal applications can be simple, cost effective, and diverse for research campuses. The following links go to sections that describe when and where solar thermal

Cold-season solar input and ambivalent thermal behavior brought by climber greenwalls

International Nuclear Information System (INIS)

Jim, C.Y.

2015-01-01

Most greenwall studies focus on cooling and energy conservation in the warm season, and tropical cold-season has received little attention. This field-experimental study in humid-subtropical Hong Kong evaluated winter thermal behavior of climber greenwalls. Orientation and weather factors regulated solar-irradiation regimes with critical impact on vegetation thermal responses. Temperature differentiation occurred mainly on sunny day, with subdued variations on cloudy and rainy days. The south greenwall on sunny day received the highest solar-energy input, bringing divergent surface temperature in three climber species. The daytime descending cooling sequence was: Control-air > Pyrostegia venusta > Bauhinia corymbosa > Ficus pumila > Control-surface. Heat-sink effect related to foliage-thickness and moisture-content influenced climber thermal responses. Exceeding a solar-irradiance threshold of 500 Wm"−"2 was a prerequisite for notable solar-warming and transpiration-cooling, bringing well-differentiated climber-surface temperature. Cooling of vegetation-surface and Anterior-ambient-air was contrasted by warming behind the greenwall. Posterior-airgap with trapped stagnant air and Posterior-concrete-surface were warmed consistently above control concrete-surface on sunny and cloudy days. This winter passive warming mechanism denotes a new dimension in thermal benefits operating behind the greenwall. The thermal-gradient can transmit heat into indoor space, with benefits on human comfort, health and energy conservation. - Highlights: • Cold-season thermal regimes and benefits of climber greenwalls in tropics was studied. • Greenwall plots were installed as a field-experiment to evaluated six related factors. • Descending cooling sequence: Pyrostegia venusta > Bauhinia corymbosa > Ficus pumila. • Solar radiation intensity and foliage heat-sink effect determined climber cooling. • Posterior airgap and Posterior concrete-surface were warmed to provide indoor

Solar thermal barometer

International Nuclear Information System (INIS)

Anon.

2010-01-01

In 2008, the European solar thermal market put on a strong spurt only to mark time in 2009 with about 4.2 million m 2 installed, which is 450000 m 2 less year-on-year. The main reasons of the decrease is the financial crisis and the low oil price, other reasons more specific to the country exist, for instance the property crisis has dragged the Spanish market down. In 2009, the solar thermal collector surface area in service in the European Union is of the magnitude of 32.6 million m 2 , equivalent to a capacity of 22.8 GWTh. The solar thermal sector is one of the renewable sectors that creates the highest number of jobs and wealth, partly because the vast majority of the system components sold in Europe are produced in Europe and partly because the sale, installation fitting and maintenance are labour-intensive. In 2009, there were 50000 direct or indirect jobs in the European solar thermal sector. The main European actors in this sector are GREENoneTEC, Bosch-Thermotechnik, Viessmann, Vaillant and Solvis. No clear recovery is expected before 2011. (A.C.)

Simulation of phase change drywalls in a passive solar building

Energy Technology Data Exchange (ETDEWEB)

Darkwa, K.; O' Callaghan, P.W. [School of the Built Environment, The Applied Energy and Environmental Engineering Group, Nottingham Trent University, Burton Street, Nottingham NG1 4BU (United Kingdom)

2006-06-15

Integration of phase change materials (PCMs) into building fabrics is considered to be one of the potential and effective ways of minimizing energy consumption and CO{sub 2} emissions in the building sector. In order to assess the thermal effectiveness of this concept, composite PCM drywall samples (i.e. randomly-mixed and laminated PCM drywalls) have been evaluated in a model passive solar building. For a broader assessment, effects of three phase change zones (narrow, intermediate and wide) of the PCM sample were considered. The results showed that the laminated PCM sample with a narrow phase change zone was capable of increasing the minimum room temperature by about 17% more than the randomly-mixed type. Even though there was some display of non-isothermal phase change process, the laminated system proved to be thermally more effective in terms of evolution and utilization of latent heat. Further heat transfer enhancement process is however required towards the development of the laminated system. [Author].

Molecular monolayers for electrical passivation and functionalization of silicon-based solar energy devices

NARCIS (Netherlands)

Veerbeek, Janneke; Firet, Nienke J.; Vijselaar, Wouter; Elbersen, R.; Gardeniers, Han; Huskens, Jurriaan

2017-01-01

Silicon-based solar fuel devices require passivation for optimal performance yet at the same time need functionalization with (photo)catalysts for efficient solar fuel production. Here, we use molecular monolayers to enable electrical passivation and simultaneous functionalization of silicon-based

Solar thermal aided power generation

International Nuclear Information System (INIS)

Hu, Eric; Yang, YongPing; Nishimura, Akira; Yilmaz, Ferdi; Kouzani, Abbas

2010-01-01

Fossil fuel based power generation is and will still be the back bone of our world economy, albeit such form of power generation significantly contributes to global CO 2 emissions. Solar energy is a clean, environmental friendly energy source for power generation, however solar photovoltaic electricity generation is not practical for large commercial scales due to its cost and high-tech nature. Solar thermal is another way to use solar energy to generate power. Many attempts to establish solar (solo) thermal power stations have been practiced all over the world. Although there are some advantages in solo solar thermal power systems, the efficiencies and costs of these systems are not so attractive. Alternately by modifying, if possible, the existing coal-fired power stations to generate green sustainable power, a much more efficient means of power generation can be reached. This paper presents the concept of solar aided power generation in conventional coal-fired power stations, i.e., integrating solar (thermal) energy into conventional fossil fuelled power generation cycles (termed as solar aided thermal power). The solar aided power generation (SAPG) concept has technically been derived to use the strong points of the two technologies (traditional regenerative Rankine cycle with relatively higher efficiency and solar heating at relatively low temperature range). The SAPG does not only contribute to increase the efficiencies of the conventional power station and reduce its emission of the greenhouse gases, but also provides a better way to use solar heat to generate the power. This paper presents the advantages of the SAPG at conceptual level.

Passivation Using Molecular Halides Increases Quantum Dot Solar Cell Performance

KAUST Repository

Lan, Xinzheng; Voznyy, Oleksandr; Kiani, Amirreza; Garcí a de Arquer, F. Pelayo; Abbas, Abdullah Saud; Kim, Gi-Hwan; Liu, Mengxia; Yang, Zhenyu; Walters, Grant; Xu, Jixian; Yuan, Mingjian; Ning, Zhijun; Fan, Fengjia; Kanjanaboos, Pongsakorn; Kramer, Illan; Zhitomirsky, David; Lee, Philip; Perelgut, Alexander; Hoogland, Sjoerd; Sargent, Edward H.

2015-01-01

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Here we report a solution-based passivation scheme is developed featuring the use of molecular iodine and PbS colloidal quantum dots (CQDs). The improved passivation translates into a longer carrier diffusion length in the solid film. This allows thicker solar-cell devices to be built while preserving efficient charge collection, leading to a certified power conversion efficiency of 9.9%, which is a new record in CQD solar cells.

Passivation Using Molecular Halides Increases Quantum Dot Solar Cell Performance

KAUST Repository

Lan, Xinzheng

2015-11-18

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Here we report a solution-based passivation scheme is developed featuring the use of molecular iodine and PbS colloidal quantum dots (CQDs). The improved passivation translates into a longer carrier diffusion length in the solid film. This allows thicker solar-cell devices to be built while preserving efficient charge collection, leading to a certified power conversion efficiency of 9.9%, which is a new record in CQD solar cells.

Effect of Organic and Inorganic Passivation in Quantum-Dot-Sensitized Solar Cells.

Science.gov (United States)

de la Fuente, Mauricio Solis; Sánchez, Rafael S; González-Pedro, Victoria; Boix, Pablo P; Mhaisalkar, S G; Rincón, Marina E; Bisquert, Juan; Mora-Seró, Iván

2013-05-02

The effect of semiconductor passivation on quantum-dot-sensitized solar cells (QDSCs) has been systematically characterized for CdS and CdS/ZnS. We have found that passivation strongly depends on the passivation agent, obtaining an enhancement of the solar cell efficiency for compounds containing amine and thiol groups and, in contrast, a decrease in performance for passivating agents with acid groups. Passivation can induce a change in the position of TiO2 conduction band and also in the recombination rate and nature, reflected in a change in the β parameter. Especially interesting is the finding that β, and consequently the fill factor can be increased with the passivation treatment. Applying this strategy, record cells of 4.65% efficiency for PbS-based QDSCs have been produced.

A completely passive continuous flow solar water purification system

Energy Technology Data Exchange (ETDEWEB)

Duff, William S.; Hodgson, David A. [Dept. of Mechanical Enginnering, Colorado State Univ., Fort Collins, CO (United States)

2008-07-01

Water-borne pathogens in developing countries cause several billion cases of disease and up to 10 million deaths each year, at least half of which are children. Solar water pasteurization is a potentially cost-effective, robust and reliable solution to these problems. A completely passively controlled solar water pasteurization system with a total collector area of 0.45 m{sup 2} has been constructed. The system most recently tested produced 337 litres per m{sup 2} of collector area of treated water on a sunny day. We developed our completely passive density-driven solar water pasteurization system over a five year span so that it now achieves reliable control for all possible variations in solar conditions. We have also substantially increased its daily pure water production efficiency over the same period. We will discuss the performance of our water purification system and provide an analyses that demonstrates that the system insures safe purified water production at all times. (orig.)

Spectrally-engineered solar thermal photovoltaic devices

Science.gov (United States)

Lenert, Andrej; Bierman, David; Chan, Walker; Celanovic, Ivan; Soljacic, Marin; Wang, Evelyn N.; Nam, Young Suk; McEnaney, Kenneth; Kraemer, Daniel; Chen, Gang

2018-03-27

A solar thermal photovoltaic device, and method of forming same, includes a solar absorber and a spectrally selective emitter formed on either side of a thermally conductive substrate. The solar absorber is configured to absorb incident solar radiation. The solar absorber and the spectrally selective emitter are configured with an optimized emitter-to-absorber area ratio. The solar thermal photovoltaic device also includes a photovoltaic cell in thermal communication with the spectrally selective emitter. The spectrally selective emitter is configured to permit high emittance for energies above a bandgap of the photovoltaic cell and configured to permit low emittance for energies below the bandgap.

Thermal performance of lived-in passive solar buildings: Pt. 2; School retrofit at Yeruham, Israel

Energy Technology Data Exchange (ETDEWEB)

Faiman, D. (Ben-Gurion Univ. of the Negev, Sede Boqer (Israel). J. Blaustein Inst. for Desert Research)

1992-07-01

This paper describes various, partially improvised, experiments that were devised in order to assess the thermal performance of a solar retrofit that was added to a school building. Typical measurements results are shown and analyzed. Two definitions are given for the system efficiency of solar retrofits to large-mass structures: one for the case when there is no backup system to complicate the analysis, and one for suggested use when auxiliary heating is present. (author).

The solarPACES strategy for the solar thermal breakthrough

International Nuclear Information System (INIS)

Burch, G.D.; Grasse, W.

1997-01-01

IEA(International Energy Agency)/SolarPACES(Solar Power and Chemical Energy systems)represents a world wide coalition for information sharing and collaboration on applications of concentrated solar energy. The current SolarPACES community has built up solar thermal system know-how over 15 years, is operating the three main solar test centres in the world. Its main activities are in the following four fields: solar thermal electric power systems, solar chemistry, solar technology and advanced applications and non-technical activities. The article presents the talk on the strategy of solarPACES given at the International Workshop on applied solar energy held in Tashkent(Uzbekistan) in June 1997. (A.A.D.)

Solar thermal power plants

International Nuclear Information System (INIS)

Schnatbaum, L.

2009-01-01

The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

Solar energy

International Nuclear Information System (INIS)

Anon.

1992-01-01

This chapter discusses the role solar energy may have in the energy future of the US. The topics discussed in the chapter include the solar resource, solar architecture including passive solar design and solar collectors, solar-thermal concentrating systems including parabolic troughs and dishes and central receivers, photovoltaic cells including photovoltaic systems for home use, and environmental, health and safety issues

solar thermal power systems advanced solar thermal technology project, advanced subsystems development

Science.gov (United States)

1979-01-01

The preliminary design for a prototype small (20 kWe) solar thermal electric generating unit was completed, consisting of several subsystems. The concentrator and the receiver collect solar energy and a thermal buffer storage with a transport system is used to provide a partially smoothed heat input to the Stirling engine. A fossil-fuel combustor is included in the receiver designs to permit operation with partial or no solar insolation (hybrid). The engine converts the heat input into mechanical action that powers a generator. To obtain electric power on a large scale, multiple solar modules will be required to operate in parallel. The small solar electric power plant used as a baseline design will provide electricity at remote sites and small communities.

Passive thermal management system for downhole electronics in harsh thermal environments

International Nuclear Information System (INIS)

Shang, Bofeng; Ma, Yupu; Hu, Run; Yuan, Chao; Hu, Jinyan; Luo, Xiaobing

2017-01-01

Highlights: • A passive thermal management system is proposed for downhole electronics. • Electronics temperature can be maintained within 125 °C for six-hour operating time. • The result shows potential application for the logging tool in oil and gas industry. - Abstract: The performance and reliability of downhole electronics will degrade in high temperature environments. Various active cooling techniques have been proposed for thermal management of such systems. However, these techniques require additional power input, cooling liquids and other moving components which complicate the system. This study presents a passive Thermal Management System (TMS) for downhole electronics. The TMS includes a vacuum flask, Phase Change Material (PCM) and heat pipes. The thermal characteristics of the TMS is evaluated experimentally. The results show that the system maintains equipment temperatures below 125 °C for a six-hour operating period in a 200 °C downhole environment, which will effectively protect the downhole electronics.

The SolarPACES strategy for the solar thermal breakthrough

Energy Technology Data Exchange (ETDEWEB)

Burch, G.D. [U.S. Department of Energy, Washington, DC (United States)

1997-12-31

Our national solar thermal research programs and our combined efforts conducted through IEA/SolarPACES have brought about many breakthroughs in the development of solar thermal technology. We have components and systems that are much more efficient, much more reliable, and can be built much more cost-efficiently than just a few years ago. As our technology development proceeds, we undoubtedly will continue to make significant progress, breakthroughs in fact, in all these areas - progress that will bring us even closer to economic parity with more conventional forms of energy. And while this progress is absolutely necessary, the question is whether it will be enough to allow solar thermal to break into the mainstream of global energy supply. Our new IEA/SolarPACES strategy, crafted and approved over the course of the past year, has recognized the changes we must face and given us license to begin to make those changes. We must begin addressing financial hurdles, work to create a more favorable regulatory and tax environment, support development of international partnerships, and expand the visibility and excitement of solar thermal technology to achieve the final breakthroughs we need to allow solar thermal energy to live up to its vast potential. (orig./AKF)

Polymeric materials for solar thermal applications

CERN Document Server

Köhl, Michael; Papillon, Philippe; Wallner, Gernot M; Saile, Sandrin

2012-01-01

Bridging the gap between basic science and technological applications, this is the first book devoted to polymers for solar thermal applications.Clearly divided into three major parts, the contributions are written by experts on solar thermal applications and polymer scientists alike. The first part explains the fundamentals of solar thermal energy especially for representatives of the plastics industry and researchers. Part two then goes on to provide introductory information on polymeric materials and processing for solar thermal experts. The third part combines both of these fields, dis

Radiation resistant passivation of silicon solar cells

International Nuclear Information System (INIS)

Swanson, R.M.; Gan, J.Y.; Gruenbaum, P.E.

1991-01-01

This patent describes a silicon solar cell having improved stability when exposed to concentrated solar radiation. It comprises a body of silicon material having a major surface for receiving radiation, a plurality of p and n conductivity regions in the body for collecting electrons and holes created by impinging radiation, and a passivation layer on the major surface including a first layer of silicon oxide in contact with the body and a polycrystalline silicon layer on the first layer of silicon oxide

Perspectives for solar thermal applications in Taiwan

International Nuclear Information System (INIS)

Chang, Keh-Chin; Lin, Wei-Min; Leu, Tzong-Shyng; Chung, Kung-Ming

2016-01-01

Taiwan has long depended on imported fossil energy. The government is thus actively promoting the use of renewable energy. Since 2000, domestic installations of solar water heaters have increased substantially because of the long-term subsidies provided for such systems. However, data on the annual installation area of solar collectors in recent years indicated that the solar thermal industry in Taiwan has reached a bottleneck. The long-term policy providing subsidies must thus be revised. It is proposed that future thermal applications in Taiwan should focus on building-integrated solar thermal, photovoltaic/thermal, and industrial heating processes. Regarding building-integrated solar thermal systems, the current subsidy model can be continued (according to area of solar collectors); nevertheless, the application of photovoltaic/thermal and industrial heating systems must be determined according to the thermal output of such systems. - Highlights: •The long-term subsidization for solar water heaters has lost effectiveness. •Solar thermal applications include BIST, PV/T and industrial heating process. •A performance-based subsidy policy should be implemented.

Surface Passivation of CIGS Solar Cells Using Gallium Oxide

KAUST Repository

Garud, Siddhartha

2018-02-27

This work proposes gallium oxide grown by plasma-enhanced atomic layer deposition, as a surface passivation material at the CdS buffer interface of Cu(In,Ga)Se2 (CIGS) solar cells. In preliminary experiments, a metal-insulator-semiconductor (MIS) structure is used to compare aluminium oxide, gallium oxide, and hafnium oxide as passivation layers at the CIGS-CdS interface. The findings suggest that gallium oxide on CIGS may show a density of positive charges and qualitatively, the least interface trap density. Subsequent solar cell results with an estimated 0.5 nm passivation layer show an substantial absolute improvement of 56 mV in open-circuit voltage (VOC), 1 mA cm−2 in short-circuit current density (JSC), and 2.6% in overall efficiency as compared to a reference (with the reference showing 8.5% under AM 1.5G).

Economic impact of latent heat thermal energy storage systems within direct steam generating solar thermal power plants with parabolic troughs

International Nuclear Information System (INIS)

Seitz, M.; Johnson, M.; Hübner, S.

2017-01-01

Highlights: • Integration of a latent heat thermal energy storage system into a solar direct steam generation power cycle. • Parametric study of solar field and storage size for determination of the optimal layout. • Evaluation of storage impact on the economic performance of the solar thermal power plant. • Economic comparison of new direct steam generation plant layout with state-of-the-art oil plant layout. - Abstract: One possible way to further reduce levelized costs of electricity of concentrated solar thermal energy is to directly use water/steam as the primary heat transfer fluid within a concentrated collector field. This so-called direct steam generation offers the opportunity of higher operating temperatures and better exergy efficiency. A technical challenge of the direct steam generation technology compared to oil-driven power cycles is a competitive storage technology for heat transfer fluids with a phase change. Latent heat thermal energy storages are suitable for storing heat at a constant temperature and can be used for direct steam generation power plants. The calculation of the economic impact of an economically optimized thermal energy storage system, based on a latent heat thermal energy storage system with phase change material, is the main focus of the presented work. To reach that goal, a thermal energy storage system for a direct steam generation power plant with parabolic troughs in the solar field was thermally designed to determine the boundary conditions. This paper discusses the economic impact of the designed thermal energy storage system based on the levelized costs of electricity results, provided via a wide parametric study. A state-of-the-art power cycle with a primary and a secondary heat transfer fluid and a two-tank thermal energy storage is used as a benchmark technology for electricity generation with solar thermal energy. The benchmark and direct steam generation systems are compared to each other, based respectively

Enhanced photovoltaic performance of inverted pyramid-based nanostructured black-silicon solar cells passivated by an atomic-layer-deposited Al2O3 layer.

Science.gov (United States)

Chen, Hong-Yan; Lu, Hong-Liang; Ren, Qing-Hua; Zhang, Yuan; Yang, Xiao-Feng; Ding, Shi-Jin; Zhang, David Wei

2015-10-07

Inverted pyramid-based nanostructured black-silicon (BS) solar cells with an Al2O3 passivation layer grown by atomic layer deposition (ALD) have been demonstrated. A multi-scale textured BS surface combining silicon nanowires (SiNWs) and inverted pyramids was obtained for the first time by lithography and metal catalyzed wet etching. The reflectance of the as-prepared BS surface was about 2% lower than that of the more commonly reported upright pyramid-based SiNW BS surface over the whole of the visible light spectrum, which led to a 1.7 mA cm(-2) increase in short circuit current density. Moreover, the as-prepared solar cells were further passivated by an ALD-Al2O3 layer. The effect of annealing temperature on the photovoltaic performance of the solar cells was investigated. It was found that the values of all solar cell parameters including short circuit current, open circuit voltage, and fill factor exhibit a further increase under an optimized annealing temperature. Minority carrier lifetime measurements indicate that the enhanced cell performance is due to the improved passivation quality of the Al2O3 layer after thermal annealing treatments. By combining these two refinements, the optimized SiNW BS solar cells achieved a maximum conversion efficiency enhancement of 7.6% compared to the cells with an upright pyramid-based SiNWs surface and conventional SiNx passivation.

The limits to solar thermal electricity

International Nuclear Information System (INIS)

Trainer, Ted

2014-01-01

The potential and limits of solar thermal power systems depend primarily on their capacity to meet electricity demand in mid-winter, and the associated cost, storage and other implications. Evidence on output and costs is analysed. Most attention is given to central receivers. Problems of low radiation levels, embodied energy costs, variability and storage are discussed and are found to set significant difficulties for large scale solar thermal supply in less than ideal latitudes and seasons. It is concluded that for solar thermal systems to meet a large fraction of anticipated global electricity demand in winter would involve prohibitive capital costs. - Highlights: • Output and capital cost data for various solar thermal technologies is examined. • Special attention is given to performance in winter. • Attention is also given to the effect of solar intermittency. • Implications for storage are considered. • It is concluded that there are significant limits to solar thermal power

Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

International Nuclear Information System (INIS)

Reichel, Christian; Feldmann, Frank; Müller, Ralph; Hermle, Martin; Glunz, Stefan W.; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

2015-01-01

Passivated contacts (poly-Si/SiO x /c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF 2 ), the ion implantation dose (5 × 10 14  cm −2 to 1 × 10 16  cm −2 ), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV oc ) of 725 and 720 mV, respectively. For p-type passivated contacts, BF 2 implantations into intrinsic a-Si yield well passivated contacts and allow for iV oc of 690 mV, whereas implanted B gives poor passivation with iV oc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V oc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF 2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V oc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts

Solar technologies for buildings. Fundamentals and practice examples. 2. rev. ed.; Solare Technologien fuer Gebaeude. Grundlagen und Praxisbeispiele

Energy Technology Data Exchange (ETDEWEB)

Eicker, Ursula

2012-07-01

Active and passive utilization of solar energy makes a significant contribution to energy supply in buildings. Solar heating and cooling systems, photovoltaic energy conversion systems and efficient daylighting and passive solar systems are available on the market and need to gain acceptance. The book presents the physical fundamentals and calculated examples for students. It also addresses engineers in practice, who are given concrete design procedures for solar technologies in domestic and administrative buildings. Subjects are, among others: Energy consumption of buildings and solar coverage potential - meteorological basis - solar powered heating - solar cooling - grid-connected photovoltaic systems - thermal analysis of building-integrated solar components - passive utilization of solar energy - lighting engineering and utilization of daylight.

Solar panel thermal cycling testing by solar simulation and infrared radiation methods

Science.gov (United States)

Nuss, H. E.

1980-01-01

For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method.

Solar-thermal jet pumping for irrigation

Science.gov (United States)

Clements, L. D.; Dellenback, P. A.; Bell, C. A.

1980-01-01

This paper describes a novel concept in solar powered irrigation pumping, gives measured performance data for the pump unit, and projected system performance. The solar-thermal jet pumping concept is centered around a conventional jet eductor pump which is commercially available at low cost. The jet eductor pump is powered by moderate temperature, moderate pressure Refrigerant-113 vapor supplied by a concentrating solar collector field. The R-113 vapor is direct condensed by the produced water and the two fluids are separated at the surface. The water goes on to use and the R-113 is repressurized and returned to the solar field. The key issue in the solar-thermal jet eductor concept is the efficiency of pump operation. Performance data from a small scale experimental unit which utilizes an electrically heated boiler in place of the solar field is presented. The solar-thermal jet eductor concept is compared with other solar irrigation concepts and optimal application situations are identified. Though having lower efficiencies than existing Rankine cycle solar-thermal irrigation systems, the mechanical and operational simplicity of this concept make it competitive with other solar powered irrigation schemes.

Solar Thermal Utilization: Past, Present and Future

Science.gov (United States)

2010-09-01

SO•C NON-FOCUSSING FLAT PLATE / (FPC) 100- 150•C For low temperature 50- 200•C COMPOUND applications PARABOLIC EVACUATED CONCENTRATOR ~ (ETC...2030 Ø 200GW BY 2050 Ø 20 MILLION SQ.METER SOLAR THERMAL COLLECTORS (20GW power) Ø 20 MILLION SOLAR LIGHTS LAUNCHING OF SOLAR INDIA SOLAR THERMAL...Temperature (20oC- 80oC) NALSUN ApplicationsThermal Conversion range SOLAR ENERGY COLLECTORS 40- GO•C UNGLAZED COLLECTORS 60- 90•C SOLAR POND 60

Solar Air Heaters with Thermal Heat Storages

OpenAIRE

Saxena, Abhishek; Goel, Varun

2013-01-01

Solar energy can be converted into different forms of energy, either to thermal energy or to electrical energy. Solar energy is converted directly into electrical power by photovoltaic modules, while solar collector converts solar energy into thermal energy. Solar collector works by absorbing the direct solar radiation and converting it into thermal energy, which can be stored in the form of sensible heat or latent heat or a combination of sensible and latent heats. A theoretical study has be...

Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

International Nuclear Information System (INIS)

Mathe, Vikas L.; Varma, Vijay; Raut, Suyog; Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R.K.; Bhoraskar, Sudha V.; Das, Asoka K.

2016-01-01

Graphical abstract: - Highlights: • Synthesis of nano crystalline Al (nAl) using DC thermal plasma reactor. • In situ passivation of nAl by palmitic acid and air. • Enhanced active aluminum content obtained for palmitic acid passivated nAl. • Palmitic acid passivated nAl are quite stable in humid atmospheres. - Abstract: Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

Energy Technology Data Exchange (ETDEWEB)

Mathe, Vikas L., E-mail: vlmathe@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Varma, Vijay; Raut, Suyog [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R.K. [High Energy Materials Research Lab, Sutarwadi, Pune 411021, Maharashtra (India); Bhoraskar, Sudha V. [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Das, Asoka K. [Utkal University, VaniVihar, Bhubaneswar, Odisha 751004 (India)

2016-04-15

Graphical abstract: - Highlights: • Synthesis of nano crystalline Al (nAl) using DC thermal plasma reactor. • In situ passivation of nAl by palmitic acid and air. • Enhanced active aluminum content obtained for palmitic acid passivated nAl. • Palmitic acid passivated nAl are quite stable in humid atmospheres. - Abstract: Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

Trends in observable passive solar design strategies for existing homes in the U.S

International Nuclear Information System (INIS)

Kruzner, Kelly; Cox, Kristin; Machmer, Brian; Klotz, Leidy

2013-01-01

Passive design strategies are among the most cost-effective methods to reduce energy consumption in buildings. However, the prevalence of these strategies in existing U.S. homes is not well understood. To help address this issue, this research evaluated a nationally-representative sample of 1000 existing homes distributed geographically across the U.S. Using satellite images, each building was evaluated for three passive design strategies: orientation, roof color, and level of shading. Several statistically significant regional trends were identified. For example, existing homes in the High Plains, Ohio Valley, Northwest, and Southern regions show a statistically significant trend towards orientation in the East–West direction, an effective passive design strategy. Less intuitively, in terms of what would seem to be optimal passive design, buildings in the High Plains and Ohio Valley generally have lighter roof colors than buildings in the warmer Southwest region. At the national level, no statistically significant trends were found towards the passive design strategies evaluated. These trends give us no reason to believe they were a major consideration in the design of existing homes. Policy measures and education may be required to take advantage of the opportunity for cost-effective energy savings through more widespread passive solar design. - Highlights: ► GoogleMaps to examine implementation of cost-effective, observable passive solar strategies in U.S. houses. ► No national trends toward passive solar design in U.S.—a missed opportunity. ► Some regional passive solar trends in U.S. for house orientation, roof color

Solar thermal power: the seamless solar link to the conventional power world

International Nuclear Information System (INIS)

Geyer, Michael; Quaschning, Volker

2000-01-01

This article focuses on solar thermal power generation and describes two solar thermal power concepts, namely, the parabolic trough or solar farm, and the solar central receiver or power tower. Details are given of grid-connected parabolic trough power plants in California and recent developments in collector design and absorber tubes, and the operation of power tower plants with different heat transfer media. Market issues are discussed, and solar thermal power projects under development, and application for support for solar thermal power projects under the Global Environment Facility's Operational Programme by Egypt, India, Iran, Mexico and Morocco are reported

Device physics underlying silicon heterojunction and passivating-contact solar cells: A topical review

KAUST Repository

Chavali, Raghu V. K.

2018-01-15

The device physics of commercially dominant diffused-junction silicon solar cells is well understood, allowing sophisticated optimization of this class of devices. Recently, so-called passivating-contact solar cell technologies have become prominent, with Kaneka setting the world\\'s silicon solar cell efficiency record of 26.63% using silicon heterojunction contacts in an interdigitated configuration. Although passivating-contact solar cells are remarkably efficient, their underlying device physics is not yet completely understood, not in the least because they are constructed from diverse materials that may introduce electronic barriers in the current flow. To bridge this gap in understanding, we explore the device physics of passivating contact silicon heterojunction (SHJ) solar cells. Here, we identify the key properties of heterojunctions that affect cell efficiency, analyze the dependence of key heterojunction properties on carrier transport under light and dark conditions, provide a self-consistent multiprobe approach to extract heterojunction parameters using several characterization techniques (including dark J-V, light J-V, C-V, admittance spectroscopy, and Suns-Voc), propose design guidelines to address bottlenecks in energy production in SHJ cells, and develop a process-to-module modeling framework to establish the module\\'s performance limits. We expect that our proposed guidelines resulting from this multiscale and self-consistent framework will improve the performance of future SHJ cells as well as other passivating contact-based solar cells.

Rapid Thermal Annealing and Hydrogen Passivation of Polycrystalline Silicon Thin-Film Solar Cells on Low-Temperature Glass

Directory of Open Access Journals (Sweden)

Mason L. Terry

2007-01-01

Full Text Available The changes in open-circuit voltage (Voc, short-circuit current density (Jsc, and internal quantum efficiency (IQE of aLuminum induced crystallization, ion-assisted deposition (ALICIA polycrystalline silicon thin-film solar cells on low-temperature glass substrates due to rapid thermal anneal (RTA treatment and subsequent remote microwave hydrogen plasma passivation (hydrogenation are examined. Voc improvements from 130 mV to 430 mV, Jsc improvements from 1.2 mA/cm2 to 11.3 mA/cm2, and peak IQE improvements from 16% to > 70% are achieved. A 1-second RTA plateau at 1000°C followed by hydrogenation increases the Jsc by a factor of 5.5. Secondary ion mass spectroscopy measurements are used to determine the concentration profiles of dopants, impurities, and hydrogen. Computer modeling based on simulations of the measured IQE data reveals that the minority carrier lifetime in the absorber region increases by 3 orders of magnitude to about 1 nanosecond (corresponding to a diffusion length of at least 1 μm due to RTA and subsequent hydrogenation. The evaluation of the changes in the quantum efficiency and Voc due to RTA and hydrogenation with computer modeling significantly improves the understanding of the limiting factors to cell performance.

Passive solar energy-efficient architectural building Design ...

African Journals Online (AJOL)

In this paper analyses have been done on the climate data for various climatic regions in North Cyprus to obtain physical architectural building design specification with a view to develop passive solar energy-efficient building. It utilizes a computer program, ARCHIPAK, together with climate data (for 25 year period) to get ...

Solar thermal and concentrated solar power barometer

International Nuclear Information System (INIS)

2013-01-01

The European concentrated solar power plant market is steeling itself for tough time ahead. The number of projects under construction is a pittance compared with 2012 that was an excellent year for installations (an additional 802.5 MW of capacity recorded). This drop is the result of the moratorium on renewable energy power plants introduced by the Spanish government. The European solar thermal market is hardly any more encouraging . EurObserv'ER holds that it slipped for the fourth year in a row (it dropped 5.5% between 2011 and 2012). The newly-installed solar thermal collector surface area in the EU now stands at 3.4 million m 2 , far short of its 2008 installation record of 4.6 million m 2 . The EU's solar thermal base to date at the end of 2012 is 29.6 GWth with 2.4 GWth installed during the year 2012. This article gives tables gathering the figures of the production for every European country for 2012 and describes the market and the general trend for every EU member

Reduction of carbon dioxide emissions by solar water heating systems and passive technologies in social housing

International Nuclear Information System (INIS)

Bessa, Vanessa M.T.; Prado, Racine T.A.

2015-01-01

Growing global concern regarding climate change motivates technological studies to minimize environmental impacts. In this context, solar water heating (SWH) systems are notably prominent in Brazil, primarily because of the abundance of solar energy in the country. However, SWH designs have not always been perfectly developed. In most projects, the installation option of the solar system only considers the electric power economy aspects and not the particular characteristics of each climatic zone. Thus, the primary objective of this paper is to assess the potential of carbon dioxide reduction with the use of SWH in comparison with electric showers in social housing in several Brazilian climatic zones. The Brazilian government authorities have created public policies to encourage the use of these technologies primarily among the low-income population. The results of this paper indicate that hot climactic regions demonstrate a low reduction of CO 2 emissions with SWH installations. Thus, solar radiation is not useful for water heating in those regions, but it does lead to a large fraction of household cooling loads, implying a demand for electrical energy for air conditioning or requiring the adoption of passive techniques to maintain indoor temperatures below threshold values. -- Graphical abstract: Display Omitted -- Highlights: •Brazil has created public policies to increase the use of solar water heating in social housing. •We have evaluated the potential for reduction of CO 2 emissions installing solar water heating. •We have found that the coldest regions have the greatest potential for reducing emissions. •Passive technologies for thermal comfort in hot climate households are more useful than solar water heating systems

The Effect of Passive Design Strategies on Thermal Performance of Female Secondary School Buildings during Warm Season in Hot Dry Climate

Directory of Open Access Journals (Sweden)

Sahar eZahiri

2016-03-01

Full Text Available This paper describes a series of field studies and simulation analysis to improve the thermal performance of school buildings in the city of Tehran in Iran during warm season. The field studies used on-site measurement and questionnaire-based survey in the warm spring season in a typical female secondary school building. The on-site monitoring assessed the indoor air temperature and humidity levels of six classrooms while the occupants completed questionnaires covering their thermal sensations and thermal preferences. Moreover, thermal simulation analysis was also carried out to evaluate and improve the thermal performance of the classrooms based on the students’ thermal requirements and passive design strategies. In this study, the environmental design guidelines for female secondary school buildings were introduced for the hot and dry climate of Tehran, using passive design strategies. The study shows that the application of passive design strategies including south and south-east orientation, 10cm thermal insulation in wall and 5cm in the roof, and the combination of 30cm side fins and overhangs as a solar shading devices, as well as all-day ventilation strategy and the use of thermal mass materials with 25cm-30cm thickness, has considerable impact on indoor air temperatures in warm season in Tehran and keeps the indoor environment in an acceptable thermal condition. The results of the field studies also indicated that most of the occupants found their thermal environment not to be comfortable and the simulation results showed that passive design techniques had a significant influence on the indoor air temperature and can keep it in an acceptable range based on the female students’ thermal requirement. Therefore, in order to enhance the indoor environment and to increase the learning performance of the students, it is necessary to use the appropriate passive design strategies, which also reduce the need for mechanical systems and

Photovoltaic. Solar thermal. Solar thermal electricity;Le Photovoltaique. Le solaire thermique. L'heliothermodynamique

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

The year 2008 was excellent for solar energy in the European Union. The growth of the installed capacity for photovoltaic was +159% (it means +4747.018 MW) to reach 9689.952 MW and that for solar thermal was +51.5% (it means +3172.5 MW) to reach 19982.7 MW. Worldwide concentrated solar thermal capacity stood at 679 MW in 2009, while this figure may seem low, the sector has a promising future ahead of it. (A.C.)

Thin Film Photovoltaic/Thermal Solar Panels

Institute of Scientific and Technical Information of China (English)

David JOHNSTON

2008-01-01

A solar panel is described.in which thin films of semiconductor are deposited onto a metal substrate.The semiconductor-metal combination forms a thin film photovoltaic cell,and also acts as a reflector,absorber tandem, which acts as a solar selective surface,thus enhancing the solar thermal performance of the collector plate.The use of thin films reduces the distance heat is required to flow from the absorbing surface to the metal plate and heat exchange conduits.Computer modelling demonstrated that,by suitable choice of materials,photovohaic efficiency call be maintained,with thermal performance slishtly reduced,compared to that for thermal-only panels.By grading the absorber layer-to reduce the band gap in the lower region-the thermal performance can be improved,approaching that for a thermal-only solar panel.

Concentrated solar thermal power - Now

Energy Technology Data Exchange (ETDEWEB)

Aringhoff, R.; Brakmann, G. [Solar Thermal Power Industry Association ESTIA, Avenue de la Fauconnerie 73, 1170 Brussels (Belgium); Geyer, M. [IEA SolarPACES Implementing Agreement, Avenida de la Paz 51, 04720 Aguadulce, Almeria (Spain); Teske, S. [Greenpeace International, Ottho Heldringstraat 5, 1066 AZ Amsterdam (Netherlands)

2005-09-15

This report demonstrates that there are no technical, economic or resource barriers to supplying 5% of the world's electricity needs from solar thermal power by 2040. It is written as practical blueprint to improve understanding of the solar thermal contribution to the world energy supply.

Investigation of Solar and Solar-Gas Thermal Energy Sources

OpenAIRE

Ivan Herec; Jan Zupa

2003-01-01

The article deals with the investigation of solar thermal sources of electrical and heat energy as well as the investigation of hybrid solar-gas thermal sources of electrical and heat energy (so called photothermal sources). Photothermal sources presented here utilize computer-controlled injection of the conversion fluid into special capillary porous substance that is adjusted to direct temperature treatment by the concentrated thermal radiation absorption.

Concentrated solar thermal power - Now

Energy Technology Data Exchange (ETDEWEB)

Aringhoff, R.; Brakmann, G. [Solar Thermal Power Industry Association ESTIA, Avenue de la Fauconnerie 73, 1170 Brussels (Belgium); Geyer, M. [IEA SolarPACES Implementing Agreement, Avenida de la Paz 51, 04720 Aguadulce, Almeria (Spain); Teske, S. [Greenpeace International, Ottho Heldringstraat 5, 1066 AZ Amsterdam (Netherlands)

2005-09-15

This report demonstrates that there are no technical, economic or resource barriers to supplying 5% of the world's electricity needs from solar thermal power by 2040. It is written as practical blueprint to improve understanding of the solar thermal contribution to the world energy supply.

A comparative study on three types of solar utilization technologies for buildings: Photovoltaic, solar thermal and hybrid photovoltaic/thermal systems

International Nuclear Information System (INIS)

Huide, Fu; Xuxin, Zhao; Lei, Ma; Tao, Zhang; Qixing, Wu; Hongyuan, Sun

2017-01-01

Highlights: • Models of Solar thermal, Photovoltaic and Photovoltaic/thermal systems are developed. • Experiments are performed to validate the simulation results. • Annual performances of the three solar systems used in china are predicted. • Energy comparison between the three solar systems is analyzed. - Abstract: Buildings need energy including heat and electricity, and both of them can be provided by the solar systems. Solar thermal and photovoltaic systems absorb the solar energy and can supply the heat and electricity for buildings, respectively. However, for the urban residential buildings, the limited available area makes installation of the solar thermal collectors and photovoltaic modules together impossible. A hybrid photovoltaic/thermal system can simultaneously generate heat and electricity, which is deemed to be quite suitable for the urban residential buildings application. And yet, for a rural house of China, the available area for installation of the solar collectors is large but daily domestic hot water demand of a rural family is generally not exceeded 300 L. If only the hybrid photovoltaic/thermal collectors are installed on the whole available area, this will lead to an overproduction of the thermal energy, especially in summer. Moreover, buildings requiring for the heat and electricity are different in different regions and different seasons. In this paper, simulation models of the solar thermal, photovoltaic and hybrid photovoltaic/thermal systems are presented, and experiments are also performed to validate the simulation results. Using the validated models, performances of the three solar systems for residential applications were predicted. And energy comparison between the three solar systems used in Hongkong, Lhasa, Shanghai and Beijing of China, respectively, were also studied. Results show that, for the urban residential building with limited available installation space, a hybrid photovoltaic/thermal system may have the

Breaking the cycle: Producer and consumer perspectives on the non-adoption of passive solar housing in the US

International Nuclear Information System (INIS)

Garrett, Vicki; Koontz, Tomas M.

2008-01-01

Creating the technologies to solve our energy and pollution problems is only one part of the solution. Getting the technologies adopted may be a larger hurdle. This study examines the adoption of a low- or no-cost technology, passive solar housing design, in the United States. Interviews with professionals involved in passive solar supply identified lack of demand as the most important factor, followed by availability, awareness, and economic incentives. Corresponding survey results from homebuyers in one region suggest that lack of demand represents not disinterest, but rather lack of availability when purchasing a home. Conventional homeowners are not familiar with passive solar design, but are predisposed to favor it, especially if it can be incorporated into traditional housing styles. In addition, to the extent that they can learn information to counter the perceptions that passive solar homes are too complicated or there is too little sun in their region, homebuyers would be more willing to purchase a passive solar home. Policy interventions to promote passive solar homes should focus on supply-side incentives as well as information for homebuyers

Breaking the cycle: Producer and consumer perspectives on the non-adoption of passive solar housing in the US

Energy Technology Data Exchange (ETDEWEB)

Garrett, Vicki; Koontz, Tomas M. [School of Environment and Natural Resources, The Ohio State University, 210 Kottman Hall, 2021 Coffey Road, Columbus, OH 43210 (United States)

2008-04-15

Creating the technologies to solve our energy and pollution problems is only one part of the solution. Getting the technologies adopted may be a larger hurdle. This study examines the adoption of a low- or no-cost technology, passive solar housing design, in the United States. Interviews with professionals involved in passive solar supply identified lack of demand as the most important factor, followed by availability, awareness, and economic incentives. Corresponding survey results from homebuyers in one region suggest that lack of demand represents not disinterest, but rather lack of availability when purchasing a home. Conventional homeowners are not familiar with passive solar design, but are predisposed to favor it, especially if it can be incorporated into traditional housing styles. In addition, to the extent that they can learn information to counter the perceptions that passive solar homes are too complicated or there is too little sun in their region, homebuyers would be more willing to purchase a passive solar home. Policy interventions to promote passive solar homes should focus on supply-side incentives as well as information for homebuyers. (author)

Supplementary material on passive solar heating concepts. A compilation of published articles

Energy Technology Data Exchange (ETDEWEB)

None

1979-05-01

A compilation of published articles and reports dealing with passive solar energy concepts for heating and cooling buildings is presented. The following are included: fundamental of passive systems, applications and technical analysis, graphic tools, and information sources. (MHR)

Approaches to passive safety in advanced thermal reactors

International Nuclear Information System (INIS)

Moses, D.L.

1986-01-01

Since 1980, there has been a proliferation of thermal reactor designs which incorporate passive safety features. The evolution of this trend is briefly traced, and the nature of various passive safety features is discussed with regard to how they have been incorporated into evolving design concepts. The key aspects of the passive safety features include reduced core power density, enhanced passive heat sinks, inherent assured shutdown mechanisms, elimination/minimization of potential leak paths from the primary coolant systems, enhanced robustness of fuel elements and improved coolant chemistry and component materials. An increased reliance on purely passive safety features typically translates into larger reactor structures at reduced power ratings. Proponents of the most innovative concepts seek to offset the increased costs by simplifying licensing requirements and reducing construction time

ZnSe passivation layer for the efficiency enhancement of CuInS2 quantum dots sensitized solar cells

International Nuclear Information System (INIS)

Peng, Zhuoyin; Liu, Yueli; Zhao, Yinghan; Chen, Keqiang; Cheng, Yuqing; Kovalev, Valery; Chen, Wen

2014-01-01

Highlights: • ZnSe is employed as passivation layer in CuInS 2 quantum dots sensitized solar cells. • Slight red-shift has been occurred in UV–vis absorption spectra with ZnSe coating. • CuInS 2 based solar cells coated by ZnSe have better efficiency than that of ZnS. • Higher rate of charge transport can be produced after coating with ZnSe. -- Abstract: The effect of ZnSe passivation layer is investigated in the CuInS 2 quantum dot sensitized solar cells, which is used to improve the photovoltaic performance. The CuInS 2 quantum dot sensitized TiO 2 photo-anodes are prepared by assembly linking technique, and then deposited by the ZnSe passivation layer using the successive ionic layer absorption and reaction technique. The optical absorption edge and photoluminescence peak have slightly red-shifted after the passivation layer coating. Under solar light illumination, the ZnSe passivation layer based CuInS 2 quantum dot sensitized solar cells have the higher photovoltaic efficiency of 0.95% and incident photon conversion efficiency response than that of pure CuInS 2 based solar cells and ZnS passivation layer based solar cells, as the electron injection rate becomes faster after coating with ZnSe passivation layer

Performance improvement of the finned passive PVT system using reflectors like removable insulation covers

International Nuclear Information System (INIS)

Ziapour, Behrooz M.; Palideh, Vahid; Mokhtari, Farhad

2016-01-01

Highlights: • A passive PVT system means the combination of a PV panel and a compact solar water heater. • Comparative study was done on performance characteristics in passive and hybrid PVT systems. • Reflectors effects on performance of a finned passive PVT system were numerically studied. • Results show that the finned passive PVT system has higher performance than the hybrid type. • Reflectors reduce the night heat losses and increase the solar radiation rate on PVT system. - Abstract: A passive photovoltaic–thermal system (PVT) is the combination of a photovoltaic (PV) panel and a compact solar water heater for co-generation of heat and electricity. This system bears considerable heat losses to ambient, particularly at noncollection times. One simple way to overcome this problem is to use a removable insulation cover on the collector's outer glazing. In this paper, the effects of the reflectors on day and night performance of a finned passive PVT system were numerically studied. At nonenergy collection time, the reflectors can turn and cover the collector cover glass as a nonconductor material. Simulation results showed that the reflectors reduce the night heat losses and increase the solar radiation rate on the absorber plate. The use of removable insulation reflectors resulted to saving extra sensibly thermal energy. Also, the solar cells power generation (P_s_c), in the case of reflectors installed, was reinforced.

Design and Development of a Solar Thermal Collector with Single Axis Solar Tracking Mechanism

Directory of Open Access Journals (Sweden)

Theebhan Mogana

2016-01-01

Full Text Available The solar energy is a source of energy that is abundant in Malaysia and can be easily harvested. However, because of the rotation of the Earth about its axis, it is impossible to harvest the solar energy to the maximum capacity if the solar thermal collector is placed fix to a certain angle. In this research, a solar thermal dish with single axis solar tracking mechanism that will rotate the dish according to the position of the sun in the sky is designed and developed, so that more solar rays can be reflected to a focal point and solar thermal energy can be harvested from the focal point. Data were collected for different weather conditions and performance of the solar thermal collector with a solar tracker were studied and compared with stationary solar thermal collector.

Solar-thermal conversion and thermal energy storage of graphene foam-based composite

KAUST Repository

Zhang, Lianbin

2016-07-11

Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

Solar-thermal conversion and thermal energy storage of graphene foam-based composites.

Science.gov (United States)

Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

2016-08-14

Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

Review of the Department of Trade and Industry passive solar programme. Pt. 2: non-domestic buildings. Final report

International Nuclear Information System (INIS)

1997-06-01

The aim of the Passive Solar Programme (PSP) was to quantify the nature, size and timing of passive solar contribution to the UK building stock and the energy savings; to determine the best and most cost effective methods of achieving savings; to explore and develop better techniques; and to transfer the information to the appropriate people. There are over 1.25 million non-domestic buildings in the UK. It has been calculated that it is technically and economically possible to use passive solar design along with improved efficiency measures to reduce energy consumption in the UK by 25% in most existing non-domestic buildings and over 50% in new buildings. From the UK Government's point of view the savings are potentially very significant, and initiatives are aimed at bringing passive solar design into wide use at the earliest possible date. The PSP was intended to encourage the use of passive solar design and displace other forms of energy consumption. The earlier passive solar programme was focused on the domestic sector, where the primary concern was to reduce energy consumed in space heating. Its extension to non-domestic buildings demanded a broader definition of the potential benefits. (author)

Solar-Thermal Engine Testing

Science.gov (United States)

Tucker, Stephen; Salvail, Pat; Haynes, Davy (Technical Monitor)

2001-01-01

A solar-thermal engine serves as a high-temperature solar-radiation absorber, heat exchanger, and rocket nozzle. collecting concentrated solar radiation into an absorber cavity and transferring this energy to a propellant as heat. Propellant gas can be heated to temperatures approaching 4,500 F and expanded in a rocket nozzle, creating low thrust with a high specific impulse (I(sub sp)). The Shooting Star Experiment (SSE) solar-thermal engine is made of 100 percent chemical vapor deposited (CVD) rhenium. The engine 'module' consists of an engine assembly, propellant feedline, engine support structure, thermal insulation, and instrumentation. Engine thermal performance tests consist of a series of high-temperature thermal cycles intended to characterize the propulsive performance of the engines and the thermal effectiveness of the engine support structure and insulation system. A silicone-carbide electrical resistance heater, placed inside the inner shell, substitutes for solar radiation and heats the engine. Although the preferred propellant is hydrogen, the propellant used in these tests is gaseous nitrogen. Because rhenium oxidizes at elevated temperatures, the tests are performed in a vacuum chamber. Test data will include transient and steady state temperatures on selected engine surfaces, propellant pressures and flow rates, and engine thrust levels. The engine propellant-feed system is designed to Supply GN2 to the engine at a constant inlet pressure of 60 psia, producing a near-constant thrust of 1.0 lb. Gaseous hydrogen will be used in subsequent tests. The propellant flow rate decreases with increasing propellant temperature, while maintaining constant thrust, increasing engine I(sub sp). In conjunction with analytical models of the heat exchanger, the temperature data will provide insight into the effectiveness of the insulation system, the structural support system, and the overall engine performance. These tests also provide experience on operational

Passive solar design studies for non-domestic buildings. Case studies

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

Of the passive solar designs reported, those for a light industrial building, a nurses hostel and a low rise office block were considered to be clearly cost effective. A retrofit study of a secondary school showed that incorporating passive solar measures into refurbishment could be cost effective. Designs for a sports hall and medium rise office block were considered to be only marginally cost effective and those for a hotel bedroom block and DIY superstore were judged not to be cost effective. The maximization of daylight penetration coupled with controls on the lighting systems produced the main energy saving. This orientation, built form, fenestration, window shape, perimeter (and overhead) daylight and atria were primary solar features. Direct gain considered in conjunction with building weight/response factor could contribute to a lesser degree. Trombe walls were shown to be generally uneconomic for this type of building and conservatories contributed to amenity value more than to savings.

Progress in passive solar energy systems. Volume 8. Part 1

Energy Technology Data Exchange (ETDEWEB)

Hayes, J.; Andrejko, D.A.

1983-01-01

This book presents the papers given at a conference sponsored by the US DOE, the Solar Energy Research Institute, SolarVision, Inc., and the Southern California Solar Energy Society. The topics considered at the conference included sizing solar energy systems for agricultural applications, a farm scale ethanol production plant, the EEC wind energy RandD program, the passive solar performance assessment of an earth-sheltered house, the ARCO 1 MW photovoltaic power plant, the performance of a dendritic web photovoltaic module, second generation point focused concentrators, linear fresnel lens concentrating photovoltaic collectors, photovoltaic conversion efficiency, amorphous silicon thin film solar cells, a photovoltaic system for a shopping center, photovoltaic power generation for the utility industry, spectral solar radiation, and the analysis of insolation data.

Passive Solar still: Recent advancement in design and related Performance.

Science.gov (United States)

Awasthi, Anuradha; Kumari, Kanchan; Panchal, Hitesh; Sathyamurthy, Ravishankar

2018-05-31

Present review paper mainly focuses on different varieties of solar stills and highlights mostly the passive solar still with advanced modifications in the design and development of material, single and multi-effect solar still with augmentation of different materials, energy absorbing, insulators, mechanisms of heat and mass transfer to improve the loss of heat and enhance the productivity of solar still. The cost-benefit analysis along with the progressive advancement for solar stills is the major highlights of this review. To increase the output of solar still nowadays, applications of advance modifications is one of the promising tools, and it is anticipated that shortly more vigor will be added in this area with the modifications in designs of solar stills.

Semiconductor-based Multilayer Selective Solar Absorber for Unconcentrated Solar Thermal Energy Conversion.

Science.gov (United States)

Thomas, Nathan H; Chen, Zhen; Fan, Shanhui; Minnich, Austin J

2017-07-13

Solar thermal energy conversion has attracted substantial renewed interest due to its applications in industrial heating, air conditioning, and electricity generation. Achieving stagnation temperatures exceeding 200 °C, pertinent to these technologies, with unconcentrated sunlight requires spectrally selective absorbers with exceptionally low emissivity in the thermal wavelength range and high visible absorptivity for the solar spectrum. In this Communication, we report a semiconductor-based multilayer selective absorber that exploits the sharp drop in optical absorption at the bandgap energy to achieve a measured absorptance of 76% at solar wavelengths and a low emittance of approximately 5% at thermal wavelengths. In field tests, we obtain a peak temperature of 225 °C, comparable to that achieved with state-of-the-art selective surfaces. With straightforward optimization to improve solar absorption, our work shows the potential for unconcentrated solar thermal systems to reach stagnation temperatures exceeding 300 °C, thereby eliminating the need for solar concentrators for mid-temperature solar applications such as supplying process heat.

Thermal solar energy, towards a sunny interval?

International Nuclear Information System (INIS)

Anon.

2017-01-01

While its market results are continuously decreasing, the thermal solar sector regains confidence with the perspectives of a new thermal legislation in France, a higher carbon tax and the growing volume of installed equipment. This document contains 5 articles, which themes are: The renewal of the thermal solar energy sector in France, notably for the building market, due to a new regulation and a reduction in costs; Several companies are developing large capacity thermal solar plant for industrial facilities (one of them covers 10000 m 2 ) while another company is developing an all-in-one containerised system (less than 1 MW); Another example is given with a Caribbean chemical company which use thermal solar energy for its processes, with a reduction of the fuel consumption by a 2.5 factor; The return of experience show that hybrid solar panels present some limitations, especially in terms of performances and sizing; A collective building (35 apartments) in the West of France has 100 pc of its heating needs (hot water production and space heating) satisfied with solar energy

Thermal-hydraulic modeling needs for passive reactors

Energy Technology Data Exchange (ETDEWEB)

Kelly, J.M. [Nuclear Regulatory Commission, Washington, DC (United States)

1997-07-01

The U.S. Nuclear Regulatory Commission has received an application for design certification from the Westinghouse Electric Corporation for an Advanced Light Water Reactor design known as the AP600. As part of the design certification process, the USNRC uses its thermal-hydraulic system analysis codes to independently audit the vendor calculations. The focus of this effort has been the small break LOCA transients that rely upon the passive safety features of the design to depressurize the primary system sufficiently so that gravity driven injection can provide a stable source for long term cooling. Of course, large break LOCAs have also been considered, but as the involved phenomena do not appear to be appreciably different from those of current plants, they were not discussed in this paper. Although the SBLOCA scenario does not appear to threaten core coolability - indeed, heatup is not even expected to occur - there have been concerns as to the performance of the passive safety systems. For example, the passive systems drive flows with small heads, consequently requiring more precision in the analysis compared to active systems methods for passive plants as compared to current plants with active systems. For the analysis of SBLOCAs and operating transients, the USNRC uses the RELAP5 thermal-hydraulic system analysis code. To assure the applicability of RELAP5 to the analysis of these transients for the AP600 design, a four year long program of code development and assessment has been undertaken.

Thermal-hydraulic modeling needs for passive reactors

International Nuclear Information System (INIS)

Kelly, J.M.

1997-01-01

The U.S. Nuclear Regulatory Commission has received an application for design certification from the Westinghouse Electric Corporation for an Advanced Light Water Reactor design known as the AP600. As part of the design certification process, the USNRC uses its thermal-hydraulic system analysis codes to independently audit the vendor calculations. The focus of this effort has been the small break LOCA transients that rely upon the passive safety features of the design to depressurize the primary system sufficiently so that gravity driven injection can provide a stable source for long term cooling. Of course, large break LOCAs have also been considered, but as the involved phenomena do not appear to be appreciably different from those of current plants, they were not discussed in this paper. Although the SBLOCA scenario does not appear to threaten core coolability - indeed, heatup is not even expected to occur - there have been concerns as to the performance of the passive safety systems. For example, the passive systems drive flows with small heads, consequently requiring more precision in the analysis compared to active systems methods for passive plants as compared to current plants with active systems. For the analysis of SBLOCAs and operating transients, the USNRC uses the RELAP5 thermal-hydraulic system analysis code. To assure the applicability of RELAP5 to the analysis of these transients for the AP600 design, a four year long program of code development and assessment has been undertaken

A hybrid solar and chemical looping combustion system for solar thermal energy storage

International Nuclear Information System (INIS)

Jafarian, Mehdi; Arjomandi, Maziar; Nathan, Graham J.

2013-01-01

Highlights: ► A novel solar–CLC hybrid system is proposed which integrates a CLC with solar thermal energy. ► The oxygen carrier particles are used as storage medium for thermal energy storage. ► A solar cavity reactor is proposed for fuel reactor. ► The absorbed solar energy is stored in the particles to produce a base heat load. -- Abstract: A novel hybrid of a solar thermal energy and a chemical looping combustion (CLC) system is proposed here, which employs the oxygen carrier particles in a CLC system to provide diurnal thermal energy storage for concentrated solar thermal energy. In taking advantage of the chemical and sensible energy storage systems that are an inherent part of a CLC system, this hybrid offers potential to achieve cost effective, base load power generation for solar energy. In the proposed system, three reservoirs have been added to a conventional CLC system to allow storage of the oxygen carrier particles, while a cavity solar receiver has been chosen for the fuel reactor. The performance of the system is evaluated using ASPEN PLUS software, with the model being validated using independent simulation result reported previously. Operating temperature, solar efficiency, solar fraction, exergy efficiency and the fraction of the solar thermal energy stored for a based load power generation application are reported.

Solar thermal power meeting - Proceedings

International Nuclear Information System (INIS)

2011-07-01

This document summarizes the presentations and debates of the first edition of the Solar thermal power meeting. Content: 1 - Opening talk (Jean-Louis BAL, SER); 2 - Solar thermal power, European and global road-maps (Cedric Philibert, IEA; Mariangels Perez Latorre, Estela); 3 - first round-table on the international development of solar energy (Philippe Lorec, DGEC France; Said Mouline, Aderee Morocco; Obaid Amrane, Masen Morocco; Kawther Lihidheb, ANME Tunisia; Abdelaziz Boumahra, Rouiba Eclairage, Algeria; Badis Derradji, NEAL Algeria; Yao Azoumah, Lesee, 2IE Foundation Burkina Faso; Mamadou Amadou Kane, MPEM Mauritania; Jean-Charles Mulet, Bertin Technologies); 4 - Second round-table on the French solar thermal offer for export (Georgina Grenon, DGEC; Stephanie Bouzigueseschmann, DG Tresor; Armand Pineda, Alstom; Florent Brunet, Mena-Areva; Roger Pujol, CNIM; Gilles David, Enertime; Michel Wohrer, Saed; Mathieu Vrinat, Sogreah; Marc Benmarraze, Solar Euromed; 5 - Presentation of Amisole - Moroccan association of solar and wind industries (Ahmed Squalli, Amisole); 6 - Third round-table on French research at the solar industry service (Gilles Flamant, Promes Lab. CNRS; Francois Moisan, Ademe; Tahar Melliti, CGI; Andre Joffre, Derbi; Michel Wohrer, Capenergies; 7 - Fourth round table on projects financing (Vincent Girard, Loan Officer BEI; Bertrand Marchais, Miga World Bank; Philippe Meunier, CDC Climat Groupe Caisse des Depots; Christian de Gromard, AFD; Laurent Belouze, Natixis; Piotr Michalowski, Loan Officer BEI); 8 - Closing of the meeting (Roger Pujol, SER)

Rankine-Brayton engine powered solar thermal aircraft

Science.gov (United States)

Bennett, Charles L [Livermore, CA

2009-12-29

A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Rankline-Brayton engine powered solar thermal aircraft

Science.gov (United States)

Bennett, Charles L [Livermore, CA

2012-03-13

A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

ZnSe passivation layer for the efficiency enhancement of CuInS{sub 2} quantum dots sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Peng, Zhuoyin; Liu, Yueli; Zhao, Yinghan; Chen, Keqiang; Cheng, Yuqing [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070 (China); Kovalev, Valery [Department of Mechanics and Mathematics, Moscow State University named after M.V. Lomonosov, Leninskie Gory 1, 119992 Moscow (Russian Federation); Chen, Wen, E-mail: chenw@whut.edu.cn [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070 (China)

2014-02-25

Highlights: • ZnSe is employed as passivation layer in CuInS{sub 2} quantum dots sensitized solar cells. • Slight red-shift has been occurred in UV–vis absorption spectra with ZnSe coating. • CuInS{sub 2} based solar cells coated by ZnSe have better efficiency than that of ZnS. • Higher rate of charge transport can be produced after coating with ZnSe. -- Abstract: The effect of ZnSe passivation layer is investigated in the CuInS{sub 2} quantum dot sensitized solar cells, which is used to improve the photovoltaic performance. The CuInS{sub 2} quantum dot sensitized TiO{sub 2} photo-anodes are prepared by assembly linking technique, and then deposited by the ZnSe passivation layer using the successive ionic layer absorption and reaction technique. The optical absorption edge and photoluminescence peak have slightly red-shifted after the passivation layer coating. Under solar light illumination, the ZnSe passivation layer based CuInS{sub 2} quantum dot sensitized solar cells have the higher photovoltaic efficiency of 0.95% and incident photon conversion efficiency response than that of pure CuInS{sub 2} based solar cells and ZnS passivation layer based solar cells, as the electron injection rate becomes faster after coating with ZnSe passivation layer.

Techno-Economic Assessment of Heat Transfer Fluid Buffering for Thermal Energy Storage in the Solar Field of Parabolic Trough Solar Thermal Power Plants

Directory of Open Access Journals (Sweden)

Jorge M. Llamas

2017-08-01

Full Text Available Currently, operating parabolic trough (PT solar thermal power plants, either solar-only or with thermal storage block, use the solar field as a heat transfer fluid (HTF thermal storage system to provide extra thermal capacity when it is needed. This is done by circulating heat transfer fluid into the solar field piping in order to create a heat fluid buffer. In the same way, by oversizing the solar field, it can work as an alternative thermal energy storage (TES system to the traditionally applied methods. This paper presents a solar field TES model for a standard solar field from a 50-MWe solar power plant. An oversized solar model is analyzed to increase the capacity storage system (HTF buffering. A mathematical model has been developed and different simulations have been carried out over a cycle of one year with six different solar multiples considered to represent the different oversized solar field configurations. Annual electricity generation and levelized cost of energy (LCOE are calculated to find the solar multiple (SM which makes the highest solar field thermal storage capacity possible within the minimum LCOE.

Device physics underlying silicon heterojunction and passivating-contact solar cells: A topical review

KAUST Repository

Chavali, Raghu V. K.; De Wolf, Stefaan; Alam, Muhammad A.

2018-01-01

The device physics of commercially dominant diffused-junction silicon solar cells is well understood, allowing sophisticated optimization of this class of devices. Recently, so-called passivating-contact solar cell technologies have become prominent

Window structure for passivating solar cells based on gallium arsenide

Science.gov (United States)

Barnett, Allen M. (Inventor)

1985-01-01

Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.

Solar engineering of thermal processes

CERN Document Server

Duffie, John A

2013-01-01

The updated fourth edition of the ""bible"" of solar energy theory and applications Over several editions, Solar Engineering of Thermal Processes has become a classic solar engineering text and reference. This revised Fourth Edition offers current coverage of solar energy theory, systems design, and applications in different market sectors along with an emphasis on solar system design and analysis using simulations to help readers translate theory into practice. An important resource for students of solar engineering, solar energy, and alternative energy as well

CURRENT TRENDS IN THE USE OF SOLAR ENERGY

OpenAIRE

Vanya Zhivkova

2013-01-01

Solar energy represents the amount of solar radiation per unit time on unit area. Solar energy is used to obtain thermal energy through solar, and electrical energy through exist for solar energy: passive and active. The utilization of solar energy is essential for the development of human civilization.

Full-spectrum volumetric solar thermal conversion via photonic nanofluids.

Science.gov (United States)

Liu, Xianglei; Xuan, Yimin

2017-10-12

Volumetric solar thermal conversion is an emerging technique for a plethora of applications such as solar thermal power generation, desalination, and solar water splitting. However, achieving broadband solar thermal absorption via dilute nanofluids is still a daunting challenge. In this work, full-spectrum volumetric solar thermal conversion is demonstrated over a thin layer of the proposed 'photonic nanofluids'. The underlying mechanism is found to be the photonic superposition of core resonances, shell plasmons, and core-shell resonances at different wavelengths, whose coexistence is enabled by the broken symmetry of specially designed composite nanoparticles, i.e., Janus nanoparticles. The solar thermal conversion efficiency can be improved by 10.8% compared with core-shell nanofluids. The extinction coefficient of Janus dimers with various configurations is also investigated to unveil the effects of particle couplings. This work provides the possibility to achieve full-spectrum volumetric solar thermal conversion, and may have potential applications in efficient solar energy harvesting and utilization.

An Isotope Study of Hydrogenation of poly-Si/SiOx Passivated Contacts for Si Solar Cells: Preprint

Energy Technology Data Exchange (ETDEWEB)

Schnabel, Manuel; Nemeth, William; van de Loo, Bas, W.H.; Macco, Bart; Kessels, Wilhelmus, M.M.; Stradins, Paul; Young, David, L.

2017-06-26

For many years, the record Si solar cell efficiency stood at 25.0%. Only recently have several companies and institutes managed to produce more efficient cells, using passivated contacts of made doped poly-Si or a-Si:H and a passivating intrinsic interlayer in all cases. Common to these designs is the need to passivate the layer stack with hydrogen. In this contribution, we perform a systematic study of passivated contact passivation by hydrogen, using poly-Si/SiOx passivated contacts on n-Cz-Si, and ALD Al2O3 followed by a forming gas anneal (FGA) as the hydrogen source. We study p-type and n-type passivated contacts with implied Voc exceeding 690 and 720 mV, respectively, and perform either the ALD step or the FGA with deuterium instead of hydrogen in order to separate the two processes via SIMS. By examining the deuterium concentration at the SiOx in both types of samples, we demonstrate that the FGA supplies negligible hydrogen species to the SiOx, regardless of whether the FGA is hydrogenated or deuterated. Instead, it supplies the thermal energy needed for hydrogen species in the Al2O3 to diffuse there. Furthermore, the concentration of hydrogen species at the SiOx can saturate while implied Voc continues to increase, showing that the energy from the FGA is also required for hydrogen species already at the SiOx to find recombination-active defects to passivate.

Solar thermal production of zinc: Program strategy

Energy Technology Data Exchange (ETDEWEB)

Steinfeld, A; Weidenkaff, A; Moeller, S; Palumbo, R [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

The solar thermal production of zinc is considered for the conversion of solar energy into storable and transportable chemical fuels. The ultimate objective is to develop a technically and economically viable technology that can produce solar zinc. The program strategy for achieving such a goal involves research on two paths: a direct path via the solar thermal splitting of ZnO in the absence of fossil fuels, and an indirect path via the solar carbothermal/CH{sub 4}-thermal reduction of Zn O, with fossil fuels (coke or natural gas) as chemical reducing agents. Both paths make use of concentrated solar energy for high-temperature process heat. The direct path brings us to the complete substitution of fossil fuels with solar fuels for a sustainable energy supply system. The indirect path creates a link between today`s fossil-fuel-based technology and tomorrow`s solar chemical technology and builds bridges between present and future energy economies. (author) 1 fig., 15 refs.

Enhancing Efficiency of Perovskite Solar Cells via Surface Passivation with Graphene Oxide Interlayer.

Science.gov (United States)

Li, Hao; Tao, Leiming; Huang, Feihong; Sun, Qiang; Zhao, Xiaojuan; Han, Junbo; Shen, Yan; Wang, Mingkui

2017-11-08

Perovskite solar cells have been demonstrated as promising low-cost and highly efficient next-generation solar cells. Enhancing V OC by minimization the interfacial recombination kinetics can further improve device performance. In this work, we for the first time reported on surface passivation of perovskite layers with chemical modified graphene oxides, which act as efficient interlayer to reduce interfacial recombination and enhance hole extraction as well. Our modeling points out that the passivation effect mainly comes from the interaction between functional group (4-fluorophenyl) and under-coordinated Pb ions. The resulting perovskite solar cells achieved high efficient power conversion efficiency of 18.75% with enhanced high open circuit V OC of 1.11 V. Ultrafast spectroscopy, photovoltage/photocurrent transient decay, and electronic impedance spectroscopy characterizations reveal the effective passivation effect and the energy loss mechanism. This work sheds light on the importance of interfacial engineering on the surface of perovskite layers and provides possible ways to improve device efficiency.

Solar Passive Modification Increase Radiation Safety Standards Inside Accelerator Building

International Nuclear Information System (INIS)

Eid, A. F.; Keshk, A. B.

2010-01-01

Irradiation processing by accelerated electrons is considering one of the most important and useful industrial irradiation treatments. It is depending on two principle attachment elements which are architecture of irradiation building and the accelerator characteristic that was arranged inside irradiation building. Negative environmental measurements were recorded inside the main building and were exceeded the international standards (humidity, air speed, high thermal effects and ozone concentration). The study showed that it is essential to improve the natural environmental standards inside the main irradiation building in order to improve the work environment and to reduce ozone concentration from 220 ppb to international standard. The main goals and advantages were achieved by using environmental architecture (desert architecture) indoor the irradiation building. The work depends on passive solar system which is economic, same architectural elements, comfort / health, and radiation safety, and without mechanical means. The experimental work was accomplished under these modifications. The registered results of various environmental concentrations have proved their normal standards.

CURRENT TRENDS IN THE USE OF SOLAR ENERGY

Directory of Open Access Journals (Sweden)

Vanya Zhivkova

2013-06-01

Full Text Available Solar energy represents the amount of solar radiation per unit time on unit area. Solar energy is used to obtain thermal energy through solar, and electrical energy through exist for solar energy: passive and active. The utilization of solar energy is essential for the development of human civilization.

Silicon heterojunction solar cell passivation in combination with nanocrystalline silicon oxide emitters

NARCIS (Netherlands)

Gatz, H.A.; Rath, J.K.; Verheijen, M.A.; Kessels, W.M.M.; Schropp, R.E.I.

2016-01-01

Silicon heterojunction solar cells (SHJ) are well known for their high efficiencies, enabled by their remarkably high open-circuit voltages (VOC). A key factor in achieving these values is a good passivation of the crystalline wafer interface. One of the restrictions during SHJ solar cell production

Market potential of solar thermal system in Malaysia

International Nuclear Information System (INIS)

Othman, M.Y.H.; Sopian, K.; Dalimin, M.N.

1992-01-01

This paper reviews the market potential for solar thermal systems in Malaysia. Our study indicates that solar thermal systems such as solar drying, solar water heating and process heating have a good potential for commercialization. The primary obstacle facing the utilization of these technologies is the financial aspects. (author)

Proposal of leak path passivation for InGaN solar cells to reduce the leakage current

Energy Technology Data Exchange (ETDEWEB)

Wang, Ke, E-mail: ke.wang@chiba-u.jp; Imai, Daichi; Kusakabe, Kazuhide [Center for SMART Green Innovation Research, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Yoshikawa, Akihiko, E-mail: yoshi@faculty.chiba-u.jp [Center for SMART Green Innovation Research, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Department of Information and Communication Engineering, Graduate School of Engineering, Kogakuin University, Nakano-cho, Hachioji, Tokyo 2665-1 (Japan)

2016-01-25

We propose some general ways to passivate the leak paths in InGaN solar cells and report some experimental evidences of its effectiveness. By adopting an AlOx passivation process, the photovoltaic performances of GaN pn-junctions and InGaN solar cells, grown by molecular beam epitaxy, have been significantly improved. The open circuit voltage under 1 sun illumination increases from 1.46 to 2.26 V for a GaN pn junction, and from 0.95 to 1.27 V for an InGaN solar cell, demonstrating evidence of leak path passivation (LPP) by AlOx. The proposed LPP is expected to be a realistic way to exploit the potential of thick and relaxed but defective InGaN for solar cell applications.

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 %.

A new structure for comparing surface passivation materials of GaAs solar cells

Science.gov (United States)

Desalvo, Gregory C.; Barnett, Allen M.

1989-01-01

The surface recombination velocity (S sub rec) for bare GaAs is typically as high as 10 to the 6th power to 10 to the 7th power cm/sec, which dramatically lowers the efficiency of GaAs solar cells. Early attempts to circumvent this problem by making an ultra thin junction (xj less than .1 micron) proved unsuccessful when compared to lowering S sub rec by surface passivation. Present day GaAs solar cells use an GaAlAs window layer to passivate the top surface. The advantages of GaAlAs in surface passivation are its high bandgap energy and lattice matching to GaAs. Although GaAlAs is successful in reducing the surface recombination velocity, it has other inherent problems of chemical instability (Al readily oxidizes) and ohmic contact formation. The search for new, more stable window layer materials requires a means to compare their surface passivation ability. Therefore, a device structure is needed to easily test the performance of different passivating candidates. Such a test device is described.

Solar 92: The 1992 American Solar Energy Society annual conference

International Nuclear Information System (INIS)

Burley, S.; Arden, M.E.

1992-01-01

The purpose of this symposium is to document the lessons learned from federal and state policies and programs in the late 1970's and 1980's aimed at promoting consumer use of solar energy. During this period the primary emphasis was on solar thermal technologies and passive solar design that could be used at the residential level, though there was also some information on stand-alone photovoltaic systems as well

IBC c-Si solar cells based on ion-implanted poly-silicon passivating contacts

NARCIS (Netherlands)

Yang, G.; Ingenito, A.; Isabella, O.; Zeman, M.

2016-01-01

Ion-implanted poly-crystalline silicon (poly-Si), in combination with a tunnel oxide layer, is investigated as a carrier-selective passivating contact in c-Si solar cells based on an interdigitated back contact (IBC) architecture. The optimized poly-Si passivating contacts enable low interface

Dynamic Characterization of an Inflatable Concentrator for Solar Thermal Propulsion

Science.gov (United States)

Leigh, Larry; Hamidzadeh, Hamid; Tinker, Michael L.; Rodriguez, Pedro I. (Technical Monitor)

2001-01-01

An inflatable structural system that is a technology demonstrator for solar thermal propulsion and other applications is characterized for structural dynamic behavior both experimentally and computationally. The inflatable structure is a pressurized assembly developed for use in orbit to support a Fresnel lens or inflatable lenticular element for focusing sunlight into a solar thermal rocket engine. When the engine temperature reaches a pre-set level, the propellant is injected into the engine, absorbs heat from an exchanger, and is expanded through the nozzle to produce thrust. The inflatable structure is a passively adaptive system in that a regulator and relief valve are utilized to maintain pressure within design limits during the full range of orbital conditions. Modeling and test activities are complicated by the fact that the polyimide film material used for construction of the inflatable is nonlinear, with modulus varying as a function of frequency, temperature, and level of excitation. Modal vibration testing and finite element modeling are described in detail in this paper. The test database is used for validation and modification of the model. This work is highly significant because of the current interest in inflatable structures for space application, and because of the difficulty in accurately modeling such systems.

Builder experience with low-cost high-value passive solar

International Nuclear Information System (INIS)

Aitken, D.W.; Neuffer, P.

1993-01-01

This article reports on passive solar tract home construction in the Reno, Nevada, area, that has enhanced the builder's market, made buying a home more affordable for the entry-level customer and made living in that home more attractive, displaced energy at $1.50/MMBtu, and attracted the local utility into seriously considering offering cash incentives for the construction and sale of those homes as a very cost-effective gas demand side management program. The builder's solar models, costs and marketing experience are described, and the utility's economic analysis is presented

Solar thermal in France

International Nuclear Information System (INIS)

Letz, T.

2006-01-01

This article gives details of Plan Soleil established in 2000 by the French Agency for Environment and Energy Management and its identification of solar hot water systems and combined domestic solar hot water and space heating as promising sectors for development. The setting up of a support scheme for investment by Plan Soleil is discussed along with subsidies and grants, manufacturers and importers, the guarantee of solar results, and the quality of plants, components, and installers. The costs of thermal solar equipment, and results of the French assessment programme are considered. The need for quality standards is stressed

Passivation Layers for Indoor Solar Cells at Low Irradiation Intensities

OpenAIRE

Rühle, K.; Rauer, M.; Rüdiger, M.; Giesecke, J.; Niewelt, T.; Schmiga, C.; Glunz, S.W.; Kasemann, M.

2012-01-01

The passivation mechanisms and qualities of Al2O3, SiNx, SiO2 and a-Si:H(i) on p- and n-type silicon are investigated by quasi-steady-state photoluminescence measurements. This technique allows effective lifetime measurements in an extremely large injection range between 1010 cm-3 and 1017 cm-3. The measurements are discussed focusing on injections below 1012 cm-3 in order to determine the most effective passivation layer for solar cells arranged for indoor applications. Fixed negative charge...

evaluation of a modified passive solar housing system for poultry

African Journals Online (AJOL)

User

The hourly efficiency of the solar brick passive system was estimated at about 78.42% in a day of May and ... to high cost and unavailability of kerosene in most developing .... sulted in intermittent rainfall, cloud cover and sunshine. From the ...

Study of the development of solar energy in Rhone-Alpes. Presentation of the photovoltaic sector, Presentation of the solar thermal sector, Sunshine mapping, Assessment of installations by the end 2009, Development potential for solar thermal energy, Development potential for solar photovoltaic energy

International Nuclear Information System (INIS)

2010-12-01

A first part proposes a wide presentation of the photovoltaic sector with an overview of largest plants, a market analysis (on the 2001-2009 period in the World, Europe and France, per technology, in terms of industrial tissue and R and D activity in France, evolution per region and per technology), a presentation of the different technologies (from the first to the third generation, in terms of costs, and of perspective for the different sectors), an environmental assessment of the different sectors (CO 2 emissions and avoided emissions), a presentation of the main actors of the photovoltaic sector (silicon producers, cell producers, thin layer producers, developers), a presentation of tracking technologies (trackers gains), and a perspective for the photovoltaic sector in Europe and in the World. In a same way, a second part presents the solar thermal sector: market analysis, active and passive technologies, solar concentration technology, environmental assessment, future perspective in Europe and in the World. A sunshine mapping is then proposed for the Rhone-Alpes region. The next part discusses various stakes: regulation for roof-based installations and for ground-based photovoltaic plants with respect to various issues (land planning, environment, biodiversity, agriculture, landscape, cultural heritage, natural risks). The next part proposes an assessment of solar thermal and photovoltaic installations at the end of 2009

Passive solar power in the shade of French energy policy, 1945-1986

International Nuclear Information System (INIS)

Teissier, Pierre

2013-01-01

The installation in 1949 of the LES (solar energy laboratory) on Mont Louis-Odeillo in the Pyrenees, was emblematic of public commitment to passive solar power. Throughout the 1950's solar furnaces were supported for research into materials and solar powered homes, moving in phase with colonial policy. Then, with the construction at Odeillo of a giant solar furnace as part of the 'policy of grandeur', policy swung in the opposite direction. The study concludes with the role that the LES played at the time of the energy crisis in the 1970's and questions the French model of not developing solar energy

Concentrating solar thermal power.

Science.gov (United States)

Müller-Steinhagen, Hans

2013-08-13

In addition to wind and photovoltaic power, concentrating solar thermal power (CSP) will make a major contribution to electricity provision from renewable energies. Drawing on almost 30 years of operational experience in the multi-megawatt range, CSP is now a proven technology with a reliable cost and performance record. In conjunction with thermal energy storage, electricity can be provided according to demand. To date, solar thermal power plants with a total capacity of 1.3 GW are in operation worldwide, with an additional 2.3 GW under construction and 31.7 GW in advanced planning stage. Depending on the concentration factors, temperatures up to 1000°C can be reached to produce saturated or superheated steam for steam turbine cycles or compressed hot gas for gas turbine cycles. The heat rejected from these thermodynamic cycles can be used for sea water desalination, process heat and centralized provision of chilled water. While electricity generation from CSP plants is still more expensive than from wind turbines or photovoltaic panels, its independence from fluctuations and daily variation of wind speed and solar radiation provides it with a higher value. To become competitive with mid-load electricity from conventional power plants within the next 10-15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations. On 30 October 2009, a number of major industrial companies joined forces to establish the so-called DESERTEC Industry Initiative, which aims at providing by 2050 15 per cent of European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. Solar thermal power plants are in the heart of this concept.

Volumetric solar thermal receiver principles and technological approach

International Nuclear Information System (INIS)

Sagie, D.; Gruntman, S.; Taragan, E.; Danino, M.; Weiss, S.; Mimon, Y.

1996-01-01

Solar energy has received much interest in recent years, being a clean free of pollution or other environmental dotage), and inexhaustible energy source. It is also considered safer than some other non conventional energy sources (like nuclear energy). The interest in solar energy is motivated mainly by the growing awareness of the environmental problems associated with the use of . conventional keels. However, solar energy may become a serious alternative only if it can be used efficiently in major energy consuming industries (like the chemical industry), or be used for electricity generation. Those facilities are nowadays solely depend on fossil fuels as the prime source of energy . The solar energy, reaches file Earth as radiation, can be utilized either by direct quantum conversion using photo-voltaic solar cells, or by converting the radiation into thermal energy, to be used directly for heating, or to feed a thermal to electric converting cycle. Alter three decades of huge spending on the development of photo-voltaic systems those devices are commercially competitive only on very small energy scale, while solar thermal commercial applications are evident. The prominent examples are the domestic heating water receivers (direct thermal), and LUZ International electricity generation plants which are currently operated on a commercial basis, supplying 80 MWe per plant. Direct thermal exploitation of solar energy is naturally more efficient than converting to electricity but is limited to specific applications and locations especially since thermal storage at high temperature is not commercially viable. Efficient electricity production at competitive price is clearly the biggest opportunity for solar energy. (authors)

Solar thermal organic rankine cycle for micro-generation

Science.gov (United States)

Alkahli, N. A.; Abdullah, H.; Darus, A. N.; Jalaludin, A. F.

2012-06-01

The conceptual design of an Organic Rankine Cycle (ORC) driven by solar thermal energy is developed for the decentralized production of electricity of up to 50 kW. Conventional Rankine Cycle uses water as the working fluid whereas ORC uses organic compound as the working fluid and it is particularly suitable for low temperature applications. The ORC and the solar collector will be sized according to the solar flux distribution in the Republic of Yemen for the required power output of 50 kW. This will be a micro power generation system that consists of two cycles, the solar thermal cycle that harness solar energy and the power cycle, which is the ORC that generates electricity. As for the solar thermal cycle, heat transfer fluid (HTF) circulates the cycle while absorbing thermal energy from the sun through a parabolic trough collector and then storing it in a thermal storage to increase system efficiency and maintains system operation during low radiation. The heat is then transferred to the organic fluid in the ORC via a heat exchanger. The organic fluids to be used and analyzed in the ORC are hydrocarbons R600a and R290.

Advanced passivation techniques for Si solar cells with high-κ dielectric materials

International Nuclear Information System (INIS)

Geng, Huijuan; Lin, Tingjui; Letha, Ayra Jagadhamma; Hwang, Huey-Liang; Kyznetsov, Fedor A.; Smirnova, Tamara P.; Saraev, Andrey A.; Kaichev, Vasily V.

2014-01-01

Electronic recombination losses at the wafer surface significantly reduce the efficiency of Si solar cells. Surface passivation using a suitable thin dielectric layer can minimize the recombination losses. Herein, advanced passivation using simple materials (Al 2 O 3 , HfO 2 ) and their compounds H (Hf) A (Al) O deposited by atomic layer deposition (ALD) was investigated. The chemical composition of Hf and Al oxide films were determined by X-ray photoelectron spectroscopy (XPS). The XPS depth profiles exhibit continuous uniform dense layers. The ALD-Al 2 O 3 film has been found to provide negative fixed charge (−6.4 × 10 11  cm −2 ), whereas HfO 2 film provides positive fixed charge (3.2 × 10 12  cm −2 ). The effective lifetimes can be improved after oxygen gas annealing for 1 min. I-V characteristics of Si solar cells with high-κ dielectric materials as passivation layers indicate that the performance is significantly improved, and ALD-HfO 2 film would provide better passivation properties than that of the ALD-Al 2 O 3 film in this research work.

Solar thermal systems successful planning and construction

CERN Document Server

Peuser, Dr Felix A; Schnauss, Martin

2013-01-01

Solar Thermal Systems summarizes the theoretical and practical knowledge gained from over 20 years of research, implementation and operation of thermal solar installations. This work provides answers to a variety of key questions by examining current solar installations, drawing upon past experiences and making proposals for future planning.- how do system components and materials behave under continuous operation?- which components have proven themselves and how are they used properly?- what are the causes of defects and how can they be avoided?- how long is the service life of modern solar i

Flexible thermal cycle test equipment for concentrator solar cells

Science.gov (United States)

Hebert, Peter H [Glendale, CA; Brandt, Randolph J [Palmdale, CA

2012-06-19

A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

Environmentally friendly education: A passive solar, straw-bale school

Energy Technology Data Exchange (ETDEWEB)

Stone, L.; Dickinson, J.

1999-07-01

The Waldorf students in the Roaring Fork Valley of western Colorado are learning their reading, writing and arithmetic in the cozy confines of a solar heated, naturally lit, straw-bale school. The Waldorf education system, founded in 1919 by Austrian Rudolph Steiner, stresses what's appropriate for the kids, not what's easiest to teach. In constructing a new school, the Waldorf community wanted a building that would reflect their philosophy. There was a long list of requirements: natural, energy efficient, light, warm, alive, and earthy. Passive solar straw-bale construction brought together all those qualities.

Proceedings of the General Committee for solar thermal energy 2015

International Nuclear Information System (INIS)

Gibert, Francois; Loyen, Richard; Khebchache, Bouzid; Cholin, Xavier; Leicher, David; Mozas, Kevin; Leclercq, Martine; Laugier, Patrick; Dias, Pedro; Kuczer, Eric; Benabdelkarim, Mohamed; Brottier, Laetitia; Soussana, Max; Cheze, David; Mugnier, Daniel; Laplagne, Valerie; Mykieta, Frederic; Ducloux, Antoine; Egret, Dominique; Noisette, Nadege; Peneau, Yvan; Seguis, Anne-Sophie; Gerard, Roland

2017-10-01

After an introducing contribution which discussed the difficult evolution of the solar thermal energy sector in 2015, contributions addressed development plans for SOCOL (a plan for collective solar thermal and solar heat) which aims at reviving the market and at opening new markets. A next set of contributions discussed how solar thermal energy can be at the service of energy transition. Following sessions addressed issues like innovation at the service of solar thermal energy, energetic display of solar systems and application of the Ecodesign and Labelling directives, and the reduction of carbon footprint and the energy dependence of territories

U.S. Light-duty Vehicle Air Conditioning Fuel Use and the Impact of Four Solar/Thermal Control Technologies

Energy Technology Data Exchange (ETDEWEB)

Rugh, John P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kekelia, Bidzina [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kreutzer, Cory J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Titov, Eugene V [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-11-28

The U.S. uses 7.6 billion gallons of fuel per year for vehicle air conditioning (A/C), equivalent to 5.7 percent of the total national light-duty vehicle (LDV) fuel use. This equates to 30 gallons/year per vehicle, or 23.5 grams (g) of carbon dioxide (CO2) per mile, for an average U.S. vehicle. A/C is a significant contribution to national fuel use; therefore, technologies that reduce A/C loads may reduce operational costs, A/C fuel use, and CO2 emissions. Since A/C is not operated during standard EPA fuel economy testing protocols, EPA provides off-cycle credits to encourage OEMs to implement advanced A/C technologies that reduce fuel use in the real world. NREL researchers assessed thermal/solar off-cycle credits available in the U.S. Environmental Protection Agency's (EPA's) Final Rule for Model Year 2017 and Later Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Economy. Credits include glazings, solar reflective paint, and passive and active cabin ventilation. Implementing solar control glass reduced CO2 emissions by 2.0 g/mi, and solar reflective paint resulted in a reduction of 0.8 g/mi. Active and passive ventilation strategies only reduced emissions by 0.1 and 0.2 g/mi, respectively. The national-level analysis process is powerful and general; it can be used to determine the impact of a wide range of new vehicle thermal technologies on fuel use, EV range, and CO2 emissions.

Solar energy in building construction practice. Solar architecture and solar engineering - fundamentals and uses. Sonnenenergie in der Baupraxis. Solar-Architektur und Solar-Technik - Grundlagen und Anwendungen

Energy Technology Data Exchange (ETDEWEB)

Weik, H.; Hahn, G.; Marschall, F.; Meister, H.; Peters, W.; Ranft, F.

1991-01-01

This anthology presents a number of overall suggestions for modern, trend-setting building construction. Details are given about active in addition to passive solar energy utilization, i.e. combinations of solar architecture and solar engineering. In an intelligible way accessible to non-physicist readers, part one discusses the related physicotechnical and town-planning fundamentals. Parts two and three are dedicated to building construction practice. They discuss the various problems of solar energy utilization from the point of view of architects, and refer to economic aspects and thermal insulation. Numerous pictures, diagrams and tables complete the book. (BWI) With 59 figs.

Review and summary of Solar Thermal Conversion Program planning assistance

Energy Technology Data Exchange (ETDEWEB)

1975-06-01

The Solar Thermal Conversion Program comprises a major part of the national solar energy program which must be continuously reviewed and modified where necessary. Modifications are typically required to reflect technical achievements and uncertainties which arise from within the program or from other technical programs, changes in budgets available for supporting the program as well as internal program funding priorities, changing goals such as through acceleration or stretch-out of the program schedule, significant organizational changes involving responsible governmental agencies, the introduction of new project management support contractors, and required budget or schedule changes occurring within individual projects that make up the Solar Thermal Conversion Program. The Aerospace Corporation has provided data to assist in planning, review, coordination, and documentation of the overall Solar Thermal Conversion Program. The Solar Thermal Conversion Program Plan is described in detail. Sections 2.0 through 5.0 cover the discussion and detail planning covering the objectives, justification, basic and alternative plans, budgets, and schedules for the Solar Thermal sub-unit portion of the Solar Electric Applications effort. Appendices B1, B2, and B3 include the March 21, March 28, and April 5, 1975, Program Plan submissions of the complete Solar Electric Applications effort. In Appendix B the Solar Thermal, Solar Photovoltaic, Wind Energy, and Ocean Thermal sub-unit texts have been condensed and formatted for integration in the overall ERDA budget package. (WHK)

Solar thermal barometer - EurObserv'ER - May 2016

International Nuclear Information System (INIS)

2016-05-01

In 2015, the European Union saw its solar thermal market contract for the seventh year in a row. EurObserv'ER puts sales of solar thermal capacity installed for the heating market (hot water and space heating) at 1861 MWth, equivalent to a 2.7 million m"2 of collectors... a further 8.6% decrease on the previous year's poor performance. Combined solar thermal capacity installed to date in the EU stands at 34.3 GWth, or 49 million m"2 of collectors

High reduction of interfacial charge recombination in colloidal quantum dot solar cells by metal oxide surface passivation.

Science.gov (United States)

Chang, Jin; Kuga, Yuki; Mora-Seró, Iván; Toyoda, Taro; Ogomi, Yuhei; Hayase, Shuzi; Bisquert, Juan; Shen, Qing

2015-03-12

Bulk heterojunction (BHJ) solar cells based on colloidal QDs and metal oxide nanowires (NWs) possess unique and outstanding advantages in enhancing light harvesting and charge collection in comparison to planar architectures. However, the high surface area of the NW structure often brings about a large amount of recombination (especially interfacial recombination) and limits the open-circuit voltage in BHJ solar cells. This problem is solved here by passivating the surface of the metal oxide component in PbS colloidal quantum dot solar cells (CQDSCs). By coating thin TiO2 layers onto ZnO-NW surfaces, the open-circuit voltage and power conversion efficiency have been improved by over 40% in PbS CQDSCs. Characterization by transient photovoltage decay and impedance spectroscopy indicated that the interfacial recombination was significantly reduced by the surface passivation strategy. An efficiency as high as 6.13% was achieved through the passivation approach and optimization for the length of the ZnO-NW arrays (device active area: 16 mm2). All solar cells were tested in air, and exhibited excellent air storage stability (without any performance decline over more than 130 days). This work highlights the significance of metal oxide passivation in achieving high performance BHJ solar cells. The charge recombination mechanism uncovered in this work could shed light on the further improvement of PbS CQDSCs and/or other types of solar cells.

Solar Thermal Power.

Science.gov (United States)

McDaniels, David K.

The different approaches to the generation of power from solar energy may be roughly divided into five categories: distributed collectors; central receivers; biomass; ocean thermal energy conversion; and photovoltaic devices. The first approach (distributed collectors) is the subject of this module. The material presented is designed to…

Passive-solar: lessons from the past

Energy Technology Data Exchange (ETDEWEB)

Kennedy, R.

The article reports on a research project conducted in Tunisia, in which ancient underground Roman homes in Bulla Reggia and similar inhabited Berber homes in Matmata were studied. Data were gathered on the passive-solar gain, compass orientations, and room measurements of the homes, and on natural lighting techniques, ventilation systems, earth-sheltered construction methods, cooling concepts, and domestic water collection systems used for these ancient dwellings. In addition, numerous sun-facing hill towns, cliff dwellings, and underground villages in Italy, France, and Spain were visited, with data recorded on window, shutter, and vent details, vegetation for climate control, and design concepts for climate-responsive town planning.

Development of Non-Tracking Solar Thermal Technology

Science.gov (United States)

Winston, Roland; Johnston, Bruce; Balkowski, Kevin

2011-11-01

The aims of this research is to develop high temperature solar thermal collectors that do not require complex solar tracking devices to maintain optimal performance. The collector technology developed through these efforts uses non-imaging optics and is referred to as an external compound parabolic concentrator. It is able to operate with a solar thermal efficiency of approximately 50% at a temperature of 200 ° C and can be readily manufactured at a cost between 15 and 18 per square foot.

Hydrogen passivation of silicon sheet solar cells

International Nuclear Information System (INIS)

Tsuo, Y.S.; Milstein, J.B.

1984-01-01

Significant improvements in the efficiencies of dendritic web and edge-supported-pulling silicon sheet solar cells have been obtained after hydrogen ion beam passivation for a period of ten minutes or less. We have studied the effects of the hydrogen ion beam treatment with respect to silicon material damage, silicon sputter rate, introduction of impurities, and changes in reflectance. The silicon sputter rate for constant ion beam flux of 0.60 +- 0.05 mA/cm 2 exhibits a maximum at approximately 1400-eV ion beam energy

Revising the limits of net gain glazing: a tool for passive solar design

Energy Technology Data Exchange (ETDEWEB)

Lee, T. [Australian National Univ., Canberra, ACT (Australia)

1996-12-31

The prevailing advice five years ago on shading of northerly fenestration had been motivated traditionally by a desire to shade the windows to sill level for as long as possible each day in summer and for as much of the summer as possible. Fixed shading, however, reduces the window area admitting direct sunlight, the top shaded section usually loses more heat to the outside than it admits. Over the whole heating season, the cumulative effect can be net loss of heat for the window as a whole, irrespective of its orientation. The concern of this study is to employ the improved thermal simulation computer program CHEETAH, and the Australian Solar Radiation Data Handbook, to revisit the original question, at what point does the combination of fixed shading of a window (due to eaves generally) and off-north orientation actually result in the window having a net heat loss (to the outside) over the whole heating season. The combined effect of eaves overhang and off-north orientation has been quantified and set out in graphical form for the use of architects seeking to apply the potential of passive solar heating to their designs. (author). 3 figs., 12 refs.

Can passive house be the solution to our energy problems, and particularly with solar energy?

OpenAIRE

Merciadri, Luca

2007-01-01

A description about the main characteristics of the passive house concept. The aim of this document is to answer to the question ``Can passive house be the solution to our energy problems, and particularly with solar energy ?'' in an objective way.

Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

Directory of Open Access Journals (Sweden)

Alexandre Hugo

2012-10-01

Full Text Available The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1 reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2 using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS software. Second, several design alternatives with improved thermal resistance for walls, ceiling and windows, increased overall air tightness, and increased window-to-wall ratio of South facing windows are evaluated with respect to the life cycle energy use, life cycle emissions and life cycle cost. The solution that minimizes the energy demand is chosen as a reference house for the study of long-term thermal storage. Third, the computer simulation of a solar heating system with solar thermal collectors and long-term thermal storage capacity is presented. Finally, the life cycle cost and life cycle energy use of the solar combisystem are estimated for flat-plate solar collectors and evacuated tube solar collectors, respectively, for the economic and climatic conditions of this study.

Hierarchical Graphene Foam for Efficient Omnidirectional Solar-Thermal Energy Conversion.

Science.gov (United States)

Ren, Huaying; Tang, Miao; Guan, Baolu; Wang, Kexin; Yang, Jiawei; Wang, Feifan; Wang, Mingzhan; Shan, Jingyuan; Chen, Zhaolong; Wei, Di; Peng, Hailin; Liu, Zhongfan

2017-10-01

Efficient solar-thermal energy conversion is essential for the harvesting and transformation of abundant solar energy, leading to the exploration and design of efficient solar-thermal materials. Carbon-based materials, especially graphene, have the advantages of broadband absorption and excellent photothermal properties, and hold promise for solar-thermal energy conversion. However, to date, graphene-based solar-thermal materials with superior omnidirectional light harvesting performances remain elusive. Herein, hierarchical graphene foam (h-G foam) with continuous porosity grown via plasma-enhanced chemical vapor deposition is reported, showing dramatic enhancement of broadband and omnidirectional absorption of sunlight, which thereby can enable a considerable elevation of temperature. Used as a heating material, the external solar-thermal energy conversion efficiency of the h-G foam impressively reaches up to ≈93.4%, and the solar-vapor conversion efficiency exceeds 90% for seawater desalination with high endurance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The thermal solar energy - September 2010

International Nuclear Information System (INIS)

Acket, C.

2010-01-01

The author first notices that the use of solar heat to produce electricity is much lesser known than the production of electricity by photovoltaic effect. He also notices that few efforts have been made in France to develop this technology (thermal solar energy, also called helio-thermodynamics). He evokes the Themis project and also some initiatives in Spain and in California. He recalls some data about solar heat, presents the solar concentration technique which either uses a parabolic configuration (point focus concentration) or a cylindrical and parabolic configuration (line concentration system). He briefly presents the different techniques used to transform solar heat into electricity and to store the electricity. He briefly presents different solutions which have been tested over the past years in France, Germany, Spain, California and Israel (tower and air, gas and Stirling cycle, tower and direct vapour production, cylindrical-parabolic collector). He discusses the effect of intermittency and the French context, and questions and discusses the choice between thermal and photovoltaic solar energy (advantages and drawbacks)

Solar applications of thermal energy storage. Final report

Energy Technology Data Exchange (ETDEWEB)

Lee, C.; Taylor, L.; DeVries, J.; Heibein, S.

1979-01-01

A technology assessment is presented on solar energy systems which use thermal energy storage. The study includes characterization of the current state-of-the-art of thermal energy storage, an assessment of the energy storage needs of solar energy systems, and the synthesis of this information into preliminary design criteria which would form the basis for detailed designs of thermal energy storage. (MHR)

Comparison of selective transmitters for solar thermal applications.

Science.gov (United States)

Taylor, Robert A; Hewakuruppu, Yasitha; DeJarnette, Drew; Otanicar, Todd P

2016-05-10

Solar thermal collectors are radiative heat exchangers. Their efficacy is dictated predominantly by their absorption of short wavelength solar radiation and, importantly, by their emission of long wavelength thermal radiation. In conventional collector designs, the receiver is coated with a selectively absorbing surface (Black Chrome, TiNOx, etc.), which serves both of these aims. As the leading commercial absorber, TiNOx consists of several thin, vapor deposited layers (of metals and ceramics) on a metal substrate. In this technology, the solar absorption to thermal emission ratio can exceed 20. If a solar system requires an analogous transparent component-one which transmits the full AM1.5 solar spectrum, but reflects long wavelength thermal emission-the technology is much less developed. Bespoke "heat mirrors" are available from optics suppliers at high cost, but the closest mass-produced commercial technology is low-e glass. Low-e glasses are designed for visible light transmission and, as such, they reflect up to 50% of available solar energy. To address this technical gap, this study investigated selected combinations of thin films that could be deposited to serve as transparent, selective solar covers. A comparative numerical analysis of feasible materials and configurations was investigated using a nondimensional metric termed the efficiency factor for selectivity (EFS). This metric is dependent on the operation temperature and solar concentration ratio of the system, so our analysis covered the practical range for these parameters. It was found that thin films of indium tin oxide (ITO) and ZnS-Ag-ZnS provided the highest EFS. Of these, ITO represents the more commercially viable solution for large-scale development. Based on these optimized designs, proof-of-concept ITO depositions were fabricated and compared to commercial depositions. Overall, this study presents a systematic guide for creating a new class of selective, transparent optics for solar

Photoswitchable Molecular Rings for Solar-Thermal Energy Storage.

Science.gov (United States)

Durgun, E; Grossman, Jeffrey C

2013-03-21

Solar-thermal fuels reversibly store solar energy in the chemical bonds of molecules by photoconversion, and can release this stored energy in the form of heat upon activation. Many conventional photoswichable molecules could be considered as solar thermal fuels, although they suffer from low energy density or short lifetime in the photoinduced high-energy metastable state, rendering their practical use unfeasible. We present a new approach to the design of chemistries for solar thermal fuel applications, wherein well-known photoswitchable molecules are connected by different linker agents to form molecular rings. This approach allows for a significant increase in both the amount of stored energy per molecule and the stability of the fuels. Our results suggest a range of possibilities for tuning the energy density and thermal stability as a function of the type of the photoswitchable molecule, the ring size, or the type of linkers.

Thermal-hydraulic unreliability of passive systems

International Nuclear Information System (INIS)

Tzanos, C.P.; Saltos, N.T.

1995-01-01

Advanced light water reactor designs like AP600 and the simplified boiling water reactor (SBWR) use passive safety systems for accident prevention and mitigation. Because these systems rely on natural forces for their operation, their unavailability due to hardware failures and human error is significantly smaller than that of active systems. However, the coolant flows predicted to be delivered by these systems can be subject to significant uncertainties, which in turn can lead to a significant uncertainty in the predicted thermal-hydraulic performance of the plant under accident conditions. Because of these uncertainties, there is a probability that an accident sequence for which a best estimate thermal-hydraulic analysis predicts no core damage (success sequence) may actually lead to core damage. For brevity, this probability will be called thermal-hydraulic unreliability. The assessment of this unreliability for all the success sequences requires very expensive computations. Moreover, the computational cost increases drastically as the required thermal-hydraulic reliability increases. The required computational effort can be greatly reduced if a bounding approach can be used that either eliminates the need to compute thermal-hydraulic unreliabilities, or it leads to the analysis of a few bounding sequences for which the required thermal-hydraulic reliability is relatively small. The objective of this paper is to present such an approach and determine the order of magnitude of the thermal-hydraulic unreliabilities that may have to be computed

Solar energy

International Nuclear Information System (INIS)

Kruisheer, N.

1992-01-01

In five brief articles product information is given on solar energy applications with special attention to the Netherlands. After an introduction on solar energy availability in the Netherlands the developments in solar boiler techniques are dealt with. Solar water heaters have advantages for the environment, and government subsidies stimulate different uses of such water heaters. Also the developments of solar cells show good prospects, not only for developing countries, but also for the industrialized countries. In brief the developments in solar energy storage and the connection of solar equipment to the grid are discussed. Finally attention is paid to the applications of passive solar energy in the housing construction, the use of transparent thermal insulation and the developments of translucent materials. 18 figs., 18 ills

10.6% Certified Colloidal Quantum Dot Solar Cells via Solvent-Polarity-Engineered Halide Passivation.

Science.gov (United States)

Lan, Xinzheng; Voznyy, Oleksandr; García de Arquer, F Pelayo; Liu, Mengxia; Xu, Jixian; Proppe, Andrew H; Walters, Grant; Fan, Fengjia; Tan, Hairen; Liu, Min; Yang, Zhenyu; Hoogland, Sjoerd; Sargent, Edward H

2016-07-13

Colloidal quantum dot (CQD) solar cells are solution-processed photovoltaics with broad spectral absorption tunability. Major advances in their efficiency have been made via improved CQD surface passivation and device architectures with enhanced charge carrier collection. Herein, we demonstrate a new strategy to improve further the passivation of CQDs starting from the solution phase. A cosolvent system is employed to tune the solvent polarity in order to achieve the solvation of methylammonium iodide (MAI) and the dispersion of hydrophobic PbS CQDs simultaneously in a homogeneous phase, otherwise not achieved in a single solvent. This process enables MAI to access the CQDs to confer improved passivation. This, in turn, allows for efficient charge extraction from a thicker photoactive layer device, leading to a certified solar cell power conversion efficiency of 10.6%, a new certified record in CQD photovoltaics.

Sulfur passivation and contact methods for GaAs nanowire solar cells

International Nuclear Information System (INIS)

Tajik, N; Peng, Z; Kuyanov, P; LaPierre, R R

2011-01-01

The effect of sulfur passivation on core-shell p-n junction GaAs nanowire (NW) solar cells has been investigated. Devices of two types were investigated, consisting of indium tin oxide contact dots or opaque Au finger electrodes. Lateral carrier transport from the NWs to the contact fingers was achieved via a p-doped GaAs surface conduction layer. NWs between the opaque contact fingers had sidewall surfaces exposed for passivation by sulfur. The relative cell efficiency increased by 19% upon passivation. The contribution of the thin film grown between the NWs to the total cell efficiency was estimated by removing the NWs using a sonication procedure. Mechanisms of carrier transport and photovoltaic effects are discussed on the basis of spatially resolved laser scanning measurements.

Hybrids of Solar Sail, Solar Electric, and Solar Thermal Propulsion for Solar-System Exploration

Science.gov (United States)

Wilcox, Brian H.

2012-01-01

Solar sails have long been known to be an attractive method of propulsion in the inner solar system if the areal density of the overall spacecraft (S/C) could be reduced to approx.10 g/sq m. It has also long been recognized that the figure (precise shape) of useful solar sails needs to be reasonably good, so that the reflected light goes mostly in the desired direction. If one could make large reflective surfaces with reasonable figure at an areal density of approx.10 g/sq m, then several other attractive options emerge. One is to use such sails as solar concentrators for solar-electric propulsion. Current flight solar arrays have a specific output of approx. 100W/kg at 1 Astronomical Unit (AU) from the sun, and near-term advances promise to significantly increase this figure. A S/C with an areal density of 10 g/sq m could accelerate up to 29 km/s per year as a solar sail at 1 AU. Using the same sail as a concentrator at 30 AU, the same spacecraft could have up to approx. 45 W of electric power per kg of total S/C mass available for electric propulsion (EP). With an EP system that is 50% power-efficient, exhausting 10% of the initial S/C mass per year as propellant, the exhaust velocity is approx. 119 km/s and the acceleration is approx. 12 km/s per year. This hybrid thus opens attractive options for missions to the outer solar system, including sample-return missions. If solar-thermal propulsion were perfected, it would offer an attractive intermediate between solar sailing in the inner solar system and solar electric propulsion for the outer solar system. In the example above, both the solar sail and solar electric systems don't have a specific impulse that is near-optimal for the mission. Solar thermal propulsion, with an exhaust velocity of the order of 10 km/s, is better matched to many solar system exploration missions. This paper derives the basic relationships between these three propulsion options and gives examples of missions that might be enabled by

Azobenzene-functionalized carbon nanotubes as high-energy density solar thermal fuels.

Science.gov (United States)

Kolpak, Alexie M; Grossman, Jeffrey C

2011-08-10

Solar thermal fuels, which reversibly store solar energy in molecular bonds, are a tantalizing prospect for clean, renewable, and transportable energy conversion/storage. However, large-scale adoption requires enhanced energy storage capacity and thermal stability. Here we present a novel solar thermal fuel, composed of azobenzene-functionalized carbon nanotubes, with the volumetric energy density of Li-ion batteries. Our work also demonstrates that the inclusion of nanoscale templates is an effective strategy for design of highly cyclable, thermally stable, and energy-dense solar thermal fuels.

Solar thermal electric power information user study

Energy Technology Data Exchange (ETDEWEB)

Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

1981-02-01

The results of a series of telephone interviews with groups of users of information on solar thermal electric power are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from five solar thermal electric power groups of respondents are analyzed: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Utilities, Electric Power Engineers, and Educators. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

Solar thermal energy conversion to electrical power

International Nuclear Information System (INIS)

Trinh, Anh-Khoi; González, Ivan; Fournier, Luc; Pelletier, Rémi; Sandoval V, Juan C.; Lesage, Frédéric J.

2014-01-01

The conversion of solar energy to electricity currently relies primarily on the photovoltaic effect in which photon bombardment of photovoltaic cells drives an electromotive force within the material. Alternatively, recent studies have investigated the potential of converting solar radiation to electricity by way of the Seebeck effect in which charge carrier mobility is generated by an asymmetric thermal differential. The present study builds upon these latest advancements in the state-of-the-art of thermoelectric system management by combining solar evacuated tube technology with commercially available Bismuth Telluride semiconductor modules. The target heat source is solar radiation and the target heat sink is thermal convection into the ambient air relying on wind aided forced convection. These sources of energy are reproduced in a laboratory controlled environment in order to maintain a thermal dipole across a thermoelectric module. The apparatus is then tested in a natural environment. The novelty of the present work lies in a net thermoelectric power gain for ambient environment applications and an experimental validation of theoretical electrical characteristics relative to a varying electrical load. - Highlights: • Solar radiation maintains a thermal tension which drives an electromotive force. • Voltage, current and electric power are reported and discussed. • Theoretical optimal thermoelectric conversion predictions are presented. • Theory is validated with experimentally measured data

Low temperature desalination using solar collectors augmented by thermal energy storage

International Nuclear Information System (INIS)

Gude, Veera Gnaneswar; Nirmalakhandan, Nagamany; Deng, Shuguang; Maganti, Anand

2012-01-01

Highlights: ► A new low temperature desalination process using solar collectors was investigated. ► A thermal energy storage tank (TES) was included for continuous process operation. ► Solar collector area and TES volumes were optimized by theoretical simulations. ► Economic analysis for the entire process was compared with and without TES tank. ► Energy and emission payback periods for the solar collector system were reported. -- Abstract: A low temperature desalination process capable of producing 100 L/d freshwater was designed to utilize solar energy harvested from flat plate solar collectors. Since solar insolation is intermittent, a thermal energy storage system was incorporated to run the desalination process round the clock. The requirements for solar collector area as well as thermal energy storage volume were estimated based on the variations in solar insolation. Results from this theoretical study confirm that thermal energy storage is a useful component of the system for conserving thermal energy to meet the energy demand when direct solar energy resource is not available. Thermodynamic advantages of the low temperature desalination using thermal energy storage, as well as energy and environmental emissions payback period of the system powered by flat plate solar collectors are presented. It has been determined that a solar collector area of 18 m 2 with a thermal energy storage volume of 3 m 3 is adequate to produce 100 L/d of freshwater round the clock considering fluctuations in the weather conditions. An economic analysis on the desalination system with thermal energy storage is also presented.

Passive House Solutions

Energy Technology Data Exchange (ETDEWEB)

Strom, I.; Joosten, L.; Boonstra, C. [DHV Sustainability Consultants, Eindhoiven (Netherlands)

2006-05-15

PEP stands for 'Promotion of European Passive Houses' and is a consortium of European partners, supported by the European Commission, Directorate General for Energy and Transport. In this working paper an overview is given of Passive House solutions. An inventory has been made of Passive House solutions for new build residences applied in each country. Based on this, the most common basic solutions have been identified and described in further detail, including the extent to which solutions are applied in common and best practice and expected barriers for the implementation in each country. An inventory per country is included in the appendix. The analysis of Passive House solutions in partner countries shows high priority with regard to the performance of the thermal envelope, such as high insulation of walls, roofs, floors and windows/ doors, thermal bridge-free construction and air tightness. Due to the required air tightness, special attention must be paid to indoor air quality through proper ventilation. Finally, efficient ((semi-)solar) heating systems for combined space and DHW heating still require a significant amount of attention in most partner countries. Other basic Passive House solutions show a smaller discrepancy with common practice and fewer barriers have been encountered in partner countries. In the next section, the general barriers in partner countries have been inventoried. For each type of barrier a suggested approach has been given. Most frequently encountered barriers in partner countries are: limited know-how; limited contractor skills; and acceptation of Passive Houses in the market. Based on the suggested approaches to overcoming barriers, this means that a great deal of attention must be paid to providing practical information and solutions to building professionals, providing practical training to installers and contractors and communication about the Passive House concept to the market.

Relation of lifetime to surface passivation for atomic-layer-deposited Al2O3 on crystalline silicon solar cell

International Nuclear Information System (INIS)

Cho, Young Joon; Song, Hee Eun; Chang, Hyo Sik

2015-01-01

Highlights: • We investigated the relation of potassium contamination on Si solar wafer to lifetime. • We deposited Al 2 O 3 layer by atomic layer deposition (ALD) on Si solar wafer after several cleaning process. • Potassium can be left on Si surface by incomplete cleaning process and degrade the Al 2 O 3 passivation quality. - Abstract: We investigated the relation of potassium contamination on a crystalline silicon (c-Si) surface after potassium hydroxide (KOH) etching to the lifetime of the c-Si solar cell. Alkaline solution was employed for saw damage removal (SDR), texturing, and planarization of a textured c-Si solar wafer prior to atomic layer deposition (ALD) Al 2 O 3 growth. In the solar-cell manufacturing process, ALD Al 2 O 3 passivation is utilized to obtain higher conversion efficiency. ALD Al 2 O 3 shows excellent surface passivation, though minority carrier lifetime varies with cleaning conditions. In the present study, we investigated the relation of potassium contamination to lifetime in solar-cell processing. The results showed that the potassium-contaminated samples, due to incomplete cleaning of KOH, had a short lifetime, thus establishing that residual potassium can degrade Al 2 O 3 surface passivation

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)

Reverse Non-Equilibrium Molecular Dynamics Demonstrate That Surface Passivation Controls Thermal Transport at Semiconductor-Solvent Interfaces.

Science.gov (United States)

Hannah, Daniel C; Gezelter, J Daniel; Schaller, Richard D; Schatz, George C

2015-06-23

We examine the role played by surface structure and passivation in thermal transport at semiconductor/organic interfaces. Such interfaces dominate thermal transport in semiconductor nanomaterials owing to material dimensions much smaller than the bulk phonon mean free path. Utilizing reverse nonequilibrium molecular dynamics simulations, we calculate the interfacial thermal conductance (G) between a hexane solvent and chemically passivated wurtzite CdSe surfaces. In particular, we examine the dependence of G on the CdSe slab thickness, the particular exposed crystal facet, and the extent of surface passivation. Our results indicate a nonmonotonic dependence of G on ligand-grafting density, with interfaces generally exhibiting higher thermal conductance for increasing surface coverage up to ∼0.08 ligands/Å(2) (75-100% of a monolayer, depending on the particular exposed facet) and decreasing for still higher coverages. By analyzing orientational ordering and solvent penetration into the ligand layer, we show that a balance of competing effects is responsible for this nonmonotonic dependence. Although the various unpassivated CdSe surfaces exhibit similar G values, the crystal structure of an exposed facet nevertheless plays an important role in determining the interfacial thermal conductance of passivated surfaces, as the density of binding sites on a surface determines the ligand-grafting densities that may ultimately be achieved. We demonstrate that surface passivation can increase G relative to a bare surface by roughly 1 order of magnitude and that, for a given extent of passivation, thermal conductance can vary by up to a factor of ∼2 between different surfaces, suggesting that appropriately tailored nanostructures may direct heat flow in an anisotropic fashion for interface-limited thermal transport.

Thermal Analysis of MIRIS Space Observation Camera for Verification of Passive Cooling

Directory of Open Access Journals (Sweden)

Duk-Hang Lee

2012-09-01

Full Text Available We conducted thermal analyses and cooling tests of the space observation camera (SOC of the multi-purpose infrared imaging system (MIRIS to verify passive cooling. The thermal analyses were conducted with NX 7.0 TMG for two cases of attitude of the MIRIS: for the worst hot case and normal case. Through the thermal analyses of the flight model, it was found that even in the worst case the telescope could be cooled to less than 206°K. This is similar to the results of the passive cooling test (~200.2°K. For the normal attitude case of the analysis, on the other hand, the SOC telescope was cooled to about 160°K in 10 days. Based on the results of these analyses and the test, it was determined that the telescope of the MIRIS SOC could be successfully cooled to below 200°K with passive cooling. The SOC is, therefore, expected to have optimal performance under cooled conditions in orbit.

Integration of plasmonic Ag nanoparticles as a back reflector in ultra-thin Cu(In,Ga)Se_2 solar cells

International Nuclear Information System (INIS)

Yin, Guanchao; Steigert, Alexander; Andrae, Patrick; Goebelt, Manuela; Latzel, Michael; Manley, Phillip; Lauermann, Iver; Christiansen, Silke; Schmid, Martina

2015-01-01

Graphical abstract: Plasmonic Ag nanoparticles as a back reflector in ultra-thin Cu(In,Ga)Se_2 (CIGSe) solar cells are investigated. Ag diffusion is successfully passivated by reducing the substrate temperature and introducing a 50 nm atomic layer deposition (ALD) prepared Al_2O_3 film. This clears the thermal obstacle in incorporating Ag nanoparticles in CIGSe solar cells. Simulations show that Ag nanoparticles have the potential to greatly enhance the light absorption in ultra-thin CIGSe solar cells. - Highlights: • Ag nanoparticles are able to diffuse through ITO substrate into CIGSe absorber even at a low substrate temperature of 440 °C. • The direction (inserting a dielectric passivation layer) to thermally block the Ag diffusion and the requirements for the passivation layer are indicated and generalized. • An atomic layer deposited Al_2O_3 layer is experimentally proved to be able to thermally passivate the Ag nanoparticles, which clears the thermal obstacle in using Ag nanoparticles as a back reflector in ultra-thin CIGSe solar cells. • It is theoretically proved that the Ag nanoparticles as a back reflector have the potential to effectively enhance the absorption in ultra-thin CIGSe solar cells. - Abstract: Integration of plasmonic Ag nanoparticles as a back reflector in ultra-thin Cu(In,Ga)Se_2 (CIGSe) solar cells is investigated. X-ray photoelectron spectroscopy results show that Ag nanoparticles underneath a Sn:In_2O_3 back contact could not be thermally passivated even at a low substrate temperature of 440 °C during CIGSe deposition. It is shown that a 50 nm thick Al_2O_3 film prepared by atomic layer deposition is able to block the diffusion of Ag, clearing the thermal obstacle in utilizing Ag nanoparticles as a back reflector in ultra-thin CIGSe solar cells. Via 3-D finite element optical simulation, it is proved that the Ag nanoparticles show the potential to contribute the effective absorption in CIGSe solar cells.

Solar thermal power plants simulation using the TRNSYS software

Energy Technology Data Exchange (ETDEWEB)

Popel, O.S.; Frid, S.E.; Shpilrain, E.E. [Institute for High Temperatures, Russian Academy of Sciences (IVTAN), Moscow (Russian Federation)

1999-03-01

The paper describes activity directed on the TRNSYS software application for mathematical simulation of solar thermal power plants. First stage of developments has been devoted to simulation and thermodynamic analysis of the Hybrid Solar-Fuel Thermal Power Plants (HSFTPP) with gas turbine installations. Three schemes of HSFTPP, namely: Gas Turbine Regenerative Cycle, Brayton Cycle with Steam Injection and Combined Brayton-Rankine Cycle,- have been assembled and tested under the TRNSYS. For this purpose 18 new models of the schemes components (gas and steam turbines, compressor, heat-exchangers, steam generator, solar receiver, condenser, controllers, etc) have been elaborated and incorporated into the TRNSYS library of 'standard' components. The authors do expect that this initiative and received results will stimulate experts involved in the mathematical simulation of solar thermal power plants to join the described activity to contribute to acceleration of development and expansion of 'Solar Thermal Power Plants' branch of the TRNSYS. The proposed approach could provide an appropriate basis for standardization of analysis, models and assumptions for well-founded comparison of different schemes of advanced solar power plants. (authors)

Mathematical model for thermal solar collectors by using magnetohydrodynamic Maxwell nanofluid with slip conditions, thermal radiation and variable thermal conductivity

Directory of Open Access Journals (Sweden)

Asif Mahmood

Full Text Available Solar energy is the cleanest, renewable and most abundant source of energy available on earth. The main use of solar energy is to heat and cool buildings, heat water and to generate electricity. There are two types of solar energy collection system, the photovoltaic systems and the solar thermal collectors. The efficiency of any solar thermal system depend on the thermophysical properties of the operating fluids and the geometry/length of the system in which fluid is flowing. In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The flow is induced by a non-uniform stretching of the porous sheet and the uniform magnetic field is applied in the transverse direction to the flow. The non-Newtonian Maxwell fluid model is utilized for the working fluid along with slip boundary conditions. Moreover the high temperature effect of thermal radiation and temperature dependent thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for cu-water and TiO2-water nanofluids. Results are presented for the velocity and temperature profiles as well as the skin friction coefficient and Nusselt number and the discussion is concluded on the effect of various governing parameters on the motion, temperature variation, velocity gradient and the rate of heat transfer at the boundary. Keywords: Solar energy, Thermal collectors, Maxwell-nanofluid, Thermal radiation, Partial slip, Variable thermal conductivity

Electrochemical-thermal modeling and microscale phase change for passive internal thermal management of lithium ion batteries.

Energy Technology Data Exchange (ETDEWEB)

Fuller, Thomas F. (Georgia Institute of Technology, Atlanta, GA); Bandhauer, Todd (Georgia Institute of Technology, Atlanta, GA); Garimella, Srinivas (Georgia Institute of Technology, Atlanta, GA)

2012-01-01

A fully coupled electrochemical and thermal model for lithium-ion batteries is developed to investigate the impact of different thermal management strategies on battery performance. In contrast to previous modeling efforts focused either exclusively on particle electrochemistry on the one hand or overall vehicle simulations on the other, the present work predicts local electrochemical reaction rates using temperature-dependent data on commercially available batteries designed for high rates (C/LiFePO{sub 4}) in a computationally efficient manner. Simulation results show that conventional external cooling systems for these batteries, which have a low composite thermal conductivity ({approx}1 W/m-K), cause either large temperature rises or internal temperature gradients. Thus, a novel, passive internal cooling system that uses heat removal through liquid-vapor phase change is developed. Although there have been prior investigations of phase change at the microscales, fluid flow at the conditions expected here is not well understood. A first-principles based cooling system performance model is developed and validated experimentally, and is integrated into the coupled electrochemical-thermal model for assessment of performance improvement relative to conventional thermal management strategies. The proposed cooling system passively removes heat almost isothermally with negligible thermal resistances between the heat source and cooling fluid. Thus, the minimization of peak temperatures and gradients within batteries allow increased power and energy densities unencumbered by thermal limitations.

Solar passive ceiling system. Final report. [Passive solar heating system with venetian blind reflectors and latent heat storage in ceiling

Energy Technology Data Exchange (ETDEWEB)

Schneider, A.R.

1980-01-01

The construction of a 1200 square foot building, with full basement, built to be used as a branch library in a rural area is described. The primary heating source is a passive solar system consisting of a south facing window system. The system consists of: a set of windows located in the south facing wall only, composed of double glazed units; a set of reflectors mounted in each window which reflects sunlight up to the ceiling (the reflectors are similar to venetian blinds); a storage area in the ceiling which absorbs the heat from the reflected sunlight and stores it in foil salt pouches laid in the ceiling; and an automated curtain which automatically covers and uncovers the south facing window system. The system is totally passive and uses no blowers, pumps or other active types of heat distribution equipment. The building contains a basement which is normally not heated, and the north facing wall is bermed four feet high around the north side.

A Low Resistance Calcium/Reduced Titania Passivated Contact for High Efficiency Crystalline Silicon Solar Cells

KAUST Repository

Allen, Thomas G.; Bullock, James; Jeangros, Quentin; Samundsett, Christian; Wan, Yimao; Cui, Jie; Hessler-Wyser, Aï cha; De Wolf, Stefaan; Javey, Ali; Cuevas, Andres

2017-01-01

Recent advances in the efficiency of crystalline silicon (c-Si) solar cells have come through the implementation of passivated contacts that simultaneously reduce recombination and resistive losses within the contact structure. In this contribution, low resistivity passivated contacts are demonstrated based on reduced titania (TiOx) contacted with the low work function metal, calcium (Ca). By using Ca as the overlying metal in the contact structure we are able to achieve a reduction in the contact resistivity of TiOx passivated contacts of up to two orders of magnitude compared to previously reported data on Al/TiOx contacts, allowing for the application of the Ca/TiOx contact to n-type c-Si solar cells with partial rear contacts. Implementing this contact structure on the cell level results in a power conversion efficiency of 21.8% where the Ca/TiOx contact comprises only ≈6% of the rear surface of the solar cell, an increase of 1.5% absolute compared to a similar device fabricated without the TiOx interlayer.

A Low Resistance Calcium/Reduced Titania Passivated Contact for High Efficiency Crystalline Silicon Solar Cells

KAUST Repository

Allen, Thomas G.

2017-02-04

Recent advances in the efficiency of crystalline silicon (c-Si) solar cells have come through the implementation of passivated contacts that simultaneously reduce recombination and resistive losses within the contact structure. In this contribution, low resistivity passivated contacts are demonstrated based on reduced titania (TiOx) contacted with the low work function metal, calcium (Ca). By using Ca as the overlying metal in the contact structure we are able to achieve a reduction in the contact resistivity of TiOx passivated contacts of up to two orders of magnitude compared to previously reported data on Al/TiOx contacts, allowing for the application of the Ca/TiOx contact to n-type c-Si solar cells with partial rear contacts. Implementing this contact structure on the cell level results in a power conversion efficiency of 21.8% where the Ca/TiOx contact comprises only ≈6% of the rear surface of the solar cell, an increase of 1.5% absolute compared to a similar device fabricated without the TiOx interlayer.

Highly reflective rear surface passivation design for ultra-thin Cu(In,Ga)Se{sub 2} solar cells

Energy Technology Data Exchange (ETDEWEB)

Vermang, Bart, E-mail: Bart.Vermang@angstrom.uu.se [Ångström Solar Center, University of Uppsala, Uppsala 75121 (Sweden); ESAT-KU Leuven, University of Leuven, Leuven 3001 (Belgium); Wätjen, Jörn Timo; Fjällström, Viktor; Rostvall, Fredrik; Edoff, Marika [Ångström Solar Center, University of Uppsala, Uppsala 75121 (Sweden); Gunnarsson, Rickard; Pilch, Iris; Helmersson, Ulf [Plasma & Coatings Physics, University of Linköping, Linköping 58183 (Sweden); Kotipalli, Ratan; Henry, Frederic; Flandre, Denis [ICTEAM/IMNC, Université Catholique de Louvain, Louvain-la-Neuve 1348 (Belgium)

2015-05-01

Al{sub 2}O{sub 3} rear surface passivated ultra-thin Cu(In,Ga)Se{sub 2} (CIGS) solar cells with Mo nano-particles (NPs) as local rear contacts are developed to demonstrate their potential to improve optical confinement in ultra-thin CIGS solar cells. The CIGS absorber layer is 380 nm thick and the Mo NPs are deposited uniformly by an up-scalable technique and have typical diameters of 150 to 200 nm. The Al{sub 2}O{sub 3} layer passivates the CIGS rear surface between the Mo NPs, while the rear CIGS interface in contact with the Mo NP is passivated by [Ga]/([Ga] + [In]) (GGI) grading. It is shown that photon scattering due to the Mo NP contributes to an absolute increase in short circuit current density of 3.4 mA/cm{sup 2}; as compared to equivalent CIGS solar cells with a standard back contact. - Highlights: • Proof-of-principle ultra-thin CIGS solar cells have been fabricated. • The cells have Mo nano-particles (NPs) as local rear contacts. • An Al{sub 2}O{sub 3} film passivates the CIGS rear surface between these nano-particles. • [Ga]/([Ga] + [In]) grading is used to reduce Mo-NP/CIGS interface recombination.

The solarisation of welfare housing: Is passive solar design a boon to those who don`t choose it?

Energy Technology Data Exchange (ETDEWEB)

Lee, T. [Australian National Univ., Canberra, ACT (Australia)

1994-12-31

The solarized housing built for what is now the ACT Housing Trust in Canberra in the early 1980`s is revisited to see what lessons can be learned. Several hundred solarized (solar efficient) houses were built by the Federal Government and were the first `passive solar` public housing in Australia. Some houses, due to a combination of slope and expansive soil foundations, were constructed with foil-insulated suspended timber floors instead of concrete slabs and thus had negligible effective thermal mass irrespective of the floor finish chosen by the tenant. It is apparent that many occupants of the early solarized dwellings revisited are not getting the full measure of energy savings and enhanced comfort that the designs allow. In several cases, occupant action in building out their own solar access indicates a low or possible even negative value is placed on their solar heating capabilities. Alternatively, it may indicate that the conceptual extension of living spaces onto a northerly patio, an integral part of many of the original designs, is so attractive as to tempt the owners into extending the roof in translucent material to protect the pleasurable times they have there. This post-occupancy evaluation suggests that acceptance of solar housing should be more closely examined to ensure that future low energy designs fully accommodate the preferred living patterns and needs of their target audience and that further attempts at occupant education are effective in reducing actual home energy consumption. (author). photos. 2 refs.

Thermal performance analysis of a solar heating plant

DEFF Research Database (Denmark)

Fan, Jianhua; Huang, Junpeng; Andersen, Ola Lie

was developed to calculate thermal performances of the plant. In the Trnsys model, three solar collector fields with a total solar collector area of 33,300 m2, a seasonal water pit heat storage of 75,000 m3, a simplified CO2 HP, a simplified ORC unit and a simplified wood chip boiler were included. The energy......Detailed measurements were carried out on a large scale solar heating plant located in southern Denmark in order to evaluate thermal performances of the plant. Based on the measurements, energy flows of the plant were evaluated. A modified Trnsys model of the Marstal solar heating plant...... consumption of the district heating net was modeled by volume flow rate and given forward and return temperatures of the district heating net. Weather data from a weather station at the site of the plant were used in the calculations. The Trnsys calculated yearly thermal performance of the solar heating plant...

Photoluminescence, structural and electrical properties of passivated a-Si:H based thin films and corresponding solar cells

International Nuclear Information System (INIS)

Pincik, E.; Kobayashi, H.; Takahashi, M.; Fujiwara, N.; Brunner, R.; Gleskova, H.; Jergel, M.; Muellerova, J.; Kucera, M.; Falcony, C.; Ortega, L.; Rusnak, J.; Mikula, M.; Zahoran, M.; Jurani, R.; Kral, M.

2004-01-01

This paper deals with the photoluminescence, structural and electrical properties of chemically passivated a-Si:H based thin films and corresponding thin film solar cells. The structures were chemically passivated in three types of KCN and HCN solutions containing MeOH and/or with water. The photoluminescence measurements were performed at 6 K using Ar laser and lock-in signal recording device containing Ge and Si photodetectors. Optically determined band gap related photoluminescence signals were observed between 1.1 and 1.7 eV. The electrical properties were measured by a high-sensitive charge version of deep level transient spectroscopy (Q-DLTS). The evolution of three basic groups of defects was observed. The structural studies were realized by the standard X-ray diffraction analysis. The cyanide treatment improved significantly the electrical characteristics of both corresponding MOS structures and solar cells due to the passivation of some parts of the dangling bonds by CN group. Particularly, the passivation of the defects at interfaces in MOS or solar cell multilayer structures was achieved which is of primary practical importance

Development and evaluation of a ceiling ventilation system enhanced by solar photovoltaic thermal collectors and phase change materials

International Nuclear Information System (INIS)

Lin, Wenye; Ma, Zhenjun; Sohel, M. Imroz; Cooper, Paul

2014-01-01

Highlights: • A novel ceiling ventilation system enhanced by PVT and PCMs was proposed. • PCM was used to increase the local thermal mass and to serve as a storage unit. • The proposed system can enhance indoor thermal comfort in winter and summer. - Abstract: This paper presents the development and performance evaluation of a novel ceiling ventilation system integrated with solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs). The PVT collectors are used to generate electricity and provide low grade heating and cooling energy for buildings by using winter daytime solar radiation and summer night-time sky radiative cooling, respectively. The PCM is integrated into the building ceiling as a part of the ceiling insulation and at the same time, as a centralized thermal energy storage to temporally store low grade energy collected from the PVT collectors. The performance of the proposed system was numerically evaluated based on a Solar Decathlon house using TRNSYS. The results showed that, in winter conditions, the proposed PVT–PCM integrated ventilation system can significantly improve the indoor thermal comfort of passive buildings without using air-conditioning systems with a maximum air temperature rise of 23.1 °C from the PVT collectors. Compared with the system using PCM but without using PVT collectors, the coefficient of thermal comfort enhancement in the kitchen, dining room and living room of the case building studied using the proposed system improved from almost zero to 0.9823 while the coefficient of thermal comfort enhancement in the study room improved from 0.0060 to 0.9921. In summer conditions, the proposed system can also enhance indoor thermal comfort through night-time sky radiative cooling

Solar energy in Amersfoort, Netherlands

International Nuclear Information System (INIS)

Eijpe, H.A.

1997-01-01

For the first time in the world a newly to be built housing area (Nieuwland in Amersfoort, Netherlands) will be constructed, exclusively on the basis of sustainability. First, the use of three forms of solar energy conversion techniques (thermal solar energy, passive solar energy and photovoltaic energy) is going to be integrated in 50 rental houses. At the end of this century 10,000 m 2 of solar cells will be installed with a capacity of 1 MWp. 2 figs

Using passive cooling strategies to improve thermal performance and reduce energy consumption of residential buildings in U.A.E. buildings

Directory of Open Access Journals (Sweden)

Hanan M. Taleb

2014-06-01

Full Text Available Passive design responds to local climate and site conditions in order to maximise the comfort and health of building users while minimising energy use. The key to designing a passive building is to take best advantage of the local climate. Passive cooling refers to any technologies or design features adopted to reduce the temperature of buildings without the need for power consumption. Consequently, the aim of this study is to test the usefulness of applying selected passive cooling strategies to improve thermal performance and to reduce energy consumption of residential buildings in hot arid climate settings, namely Dubai, United Arab Emirates. One case building was selected and eight passive cooling strategies were applied. Energy simulation software – namely IES – was used to assess the performance of the building. Solar shading performance was also assessed using Sun Cast Analysis, as a part of the IES software. Energy reduction was achieved due to both the harnessing of natural ventilation and the minimising of heat gain in line with applying good shading devices alongside the use of double glazing. Additionally, green roofing proved its potential by acting as an effective roof insulation. The study revealed several significant findings including that the total annual energy consumption of a residential building in Dubai may be reduced by up to 23.6% when a building uses passive cooling strategies.

Solar thermal technology report, FY 1981. Volume 1: Executive summary

Science.gov (United States)

1982-01-01

The activities of the Department of Energy's Solar Thermal Technology Program are discussed. Highlights of technical activities and brief descriptions of each technology are given. Solar thermal conversion concepts are discussed in detail, particularily concentrating collectors and salt-gradient solar ponds.

STDAC: Solar Thermal Design Assistance Center annual report fiscal year 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

The Solar Thermal Design Assistance Center (STDAC) at Sandia is a resource provided by the DOE Solar Thermal Program. The STDAC`s major objective is to accelerate the use of solar thermal systems by providing direct technical assistance to users in industry, government, and foreign countries; cooperating with industry to test, evaluate, and develop renewable energy systems and components; and educating public and private professionals, administrators, and decision makers. This FY94 report highlights the activities and accomplishments of the STDAC. In 1994, the STDAC continued to provide significant direct technical assistance to domestic and international organizations in industry, government, and education, Applying solar thermal technology to solve energy problems is a vital element of direct technical assistance. The STDAC provides information on the status of new, existing, and developing solar technologies; helps users screen applications; predicts the performance of components and systems; and incorporates the experience of Sandia`s solar energy personnel and facilities to provide expert guidance. The STDAC directly enhances the US solar industry`s ability to successfully bring improved systems to the marketplace. By collaborating with Sandia`s Photovoltaic Design Assistance Center and the National Renewable Energy Laboratory the STDAC is able to offer each customer complete service in applying solar thermal technology. At the National Solar Thermal Test Facility the STDAC tests and evaluates new and innovative solar thermal technologies. Evaluations are conducted in dose cooperation with manufacturers, and the results are used to improve the product and/or quantify its performance characteristics. Manufacturers, in turn, benefit from the improved design, economic performance, and operation of their solar thermal technology. The STDAC provides cost sharing and in-kind service to manufacturers in the development and improvement of solar technology.

Research on passive solar energy application in Cyprus. Part 1. Meteorological characteristics of Cyprus

Energy Technology Data Exchange (ETDEWEB)

Ishihara, O; Savva, M [Kumamoto University, Kumamoto (Japan); Saito, I [Yatsushiro Institute of Technology, Kumamoto (Japan)

1996-10-27

For application of passive solar systems to houses in Cyprus, meteorological and geographical characteristics were studied. Solar energy is not yet in wide use in Cyprus. Meteorological subjects are also not yet clarified for application of passive solar systems to houses. Annual temperature difference is estimated to be nearly 10{degree}C between the lowland and highland, and a drop in temperature with altitude is 0.33-0.76{degree}C/100m. Sunshine duration is longer in summer in everywhere showing 10-13.2 hours in August, while it is shorter in winter showing 3.5-6 hours in January. It is shorter in highland than lowland all the year through. Solar radiation intensity is obviously lower in winter than summer. Relative humidity is considerably low in highland, and it is low during the daytime in summer in lowland. In general, the relative humidity remarkably increases in the night all the year through and the daytime in winter. As the survey result, meteorological conditions are more suitable in Cyprus than Tokyo and Kumamoto for application of solar systems to houses. 4 refs., 10 figs., 1 tab.

Beam-Forming Concentrating Solar Thermal Array Power Systems

Science.gov (United States)

Cwik, Thomas A. (Inventor); Dimotakis, Paul E. (Inventor); Hoppe, Daniel J. (Inventor)

2016-01-01

The present invention relates to concentrating solar-power systems and, more particularly, beam-forming concentrating solar thermal array power systems. A solar thermal array power system is provided, including a plurality of solar concentrators arranged in pods. Each solar concentrator includes a solar collector, one or more beam-forming elements, and one or more beam-steering elements. The solar collector is dimensioned to collect and divert incoming rays of sunlight. The beam-forming elements intercept the diverted rays of sunlight, and are shaped to concentrate the rays of sunlight into a beam. The steering elements are shaped, dimensioned, positioned, and/or oriented to deflect the beam toward a beam output path. The beams from the concentrators are converted to heat at a receiver, and the heat may be temporarily stored or directly used to generate electricity.

2D layered insulator hexagonal boron nitride enabled surface passivation in dye sensitized solar cells.

Science.gov (United States)

Shanmugam, Mariyappan; Jacobs-Gedrim, Robin; Durcan, Chris; Yu, Bin

2013-11-21

A two-dimensional layered insulator, hexagonal boron nitride (h-BN), is demonstrated as a new class of surface passivation materials in dye-sensitized solar cells (DSSCs) to reduce interfacial carrier recombination. We observe ~57% enhancement in the photo-conversion efficiency of the DSSC utilizing h-BN coated semiconductor TiO2 as compared with the device without surface passivation. The h-BN coated TiO2 is characterized by Raman spectroscopy to confirm the presence of highly crystalline, mixed monolayer/few-layer h-BN nanoflakes on the surface of TiO2. The passivation helps to minimize electron-hole recombination at the TiO2/dye/electrolyte interfaces. The DSSC with h-BN passivation exhibits significantly lower dark saturation current in the low forward bias region and higher saturation in the high forward bias region, respectively, suggesting that the interface quality is largely improved without impeding carrier transport at the material interface. The experimental results reveal that the emerging 2D layered insulator could be used for effective surface passivation in solar cell applications attributed to desirable material features such as high crystallinity and self-terminated/dangling-bond-free atomic planes as compared with high-k thin-film dielectrics.

Tunnel oxide passivated rear contact for large area n-type front junction silicon solar cells providing excellent carrier selectivity

Directory of Open Access Journals (Sweden)

Yuguo Tao

2016-01-01

Full Text Available Carrier-selective contact with low minority carrier recombination and efficient majority carrier transport is mandatory to eliminate metal-induced recombination for higher energy conversion efficiency for silicon (Si solar cells. In the present study, the carrier-selective contact consists of an ultra-thin tunnel oxide and a phosphorus-doped polycrystalline Si (poly-Si thin film formed by plasma enhanced chemical vapor deposition (PECVD and subsequent thermal crystallization. It is shown that the poly-Si film properties (doping level, crystallization and dopant activation anneal temperature are crucial for achieving excellent contact passivation quality. It is also demonstrated quantitatively that the tunnel oxide plays a critical role in this tunnel oxide passivated contact (TOPCON scheme to realize desired carrier selectivity. Presence of tunnel oxide increases the implied Voc (iVoc by ~ 125 mV. The iVoc value as high as 728 mV is achieved on symmetric structure with TOPCON on both sides. Large area (239 cm2 n-type Czochralski (Cz Si solar cells are fabricated with homogeneous implanted boron emitter and screen-printed contact on the front and TOPCON on the back, achieving 21.2% cell efficiency. Detailed analysis shows that the performance of these cells is mainly limited by boron emitter recombination on the front side.

Scenarios for solar thermal energy applications in Brazil

International Nuclear Information System (INIS)

Martins, F.R.; Abreu, S.L.; Pereira, E.B.

2012-01-01

The Solar and Wind Energy Resource Assessment (SWERA) database is used to prepare and discuss scenarios for solar thermal applications in Brazil. The paper discusses low temperature applications (small and large scale water heating) and solar power plants for electricity production (concentrated solar power plants and solar chimney plants) in Brazil. The results demonstrate the feasibility of large-scale application of solar energy for water heating and electricity generation in Brazil. Payback periods for water heating systems are typically below 4 years if they were used to replace residential electric showerheads in low-income families. Large-scale water heating systems also present high feasibility and many commercial companies are adopting this technology to reduce operational costs. The best sites to set up CSP plants are in the Brazilian semi-arid region where the annual energy achieves 2.2 MW h/m 2 and averages of daily solar irradiation are larger than 5.0 kW h/m 2 /day. The western area of Brazilian Northeastern region meets all technical requirements to exploit solar thermal energy for electricity generation based on solar chimney technology. Highlights: ► Scenarios for solar thermal applications are presented. ► Payback is typically below 4 years for small scale water heating systems. ► Large-scale water heating systems also present high feasibility. ► The Brazilian semi-arid region is the best sites for CSP and chimney tower plants.

Thermal efficiency of low cost solar collectors - CSBC; Eficiencia termica de coletores solares de baixo custo - CSBC

Energy Technology Data Exchange (ETDEWEB)

Pereira, Renato C.; Shiota, Robson T.; Mello, Samuel F.; Assis Junior, Valdir; Bartoli, Julio R. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Quimica. Dept. de Tecnologia de Polimeros

2006-07-01

The thermal performance of a low cost flat panel solar collector was measured. This Low Cost Solar Collector is a novel concept for water heating using only thermoplastics materials, used on building: ceiling and tubes made of unplasticized PVC, but without transparent cover. The top side of the UPVC panel was black painted to be the solar radiation absorber surface. Prototypes were installed on two charity houses around Campinas and at the FEQ campus, being used without any trouble for one year. The thermal efficiency analysis followed ABNT NBR 10184 standard at the Green-Solar Laboratory, Brazilian Centre for Development of Solar Thermal Energy, PUC-Minas. It was measured a thermal efficiency of 67%, compared to the 75% usually found on conventional solar collectors made of copper tubes and with glass cover. (author)

National Solar Thermal Test Facility

Data.gov (United States)

Federal Laboratory Consortium — The National Solar Thermal Test Facility (NSTTF) is the only test facility in the United States of its type. This unique facility provides experimental engineering...

The challenge of screen printed Ag metallization on nano-scale poly-silicon passivated contacts for silicon solar cells

Science.gov (United States)

Jiang, Lin; Song, Lixin; Yan, Li; Becht, Gregory; Zhang, Yi; Hoerteis, Matthias

2017-08-01

Passivated contacts can be used to reduce metal-induced recombination for higher energy conversion efficiency for silicon solar cells, and are obtained increasing attentions by PV industries in recent years. The reported thicknesses of passivated contact layers are mostly within tens of nanometer range, and the corresponding metallization methods are realized mainly by plating/evaporation technology. This high cost metallization cannot compete with the screen printing technology, and may affect its market potential comparing with the presently dominant solar cell technology. Very few works have been reported on screen printing metallization on passivated contact solar cells. Hence, there is a rising demand to realize screen printing metallization technology on this topic. In this work, we investigate applying screen printing metallization pastes on poly-silicon passivated contacts. The critical challenge for us is to build low contact resistance that can be competitive to standard technology while restricting the paste penetrations within the thin nano-scale passivated contact layers. The contact resistivity of 1.1mohm-cm2 and the open circuit voltages > 660mV are achieved, and the most appropriate thickness range is estimated to be around 80 150nm.

Advances in solar thermal energy in Uruguay

International Nuclear Information System (INIS)

Franco Noceto, P.

2012-01-01

This article is about the law 18585 which declared de solar thermal energy as national interest. This law establishes the obligation to incorporate solar heating systems in health care centers, hotels and sports clubs.

Crystalline Silicon Solar Cells with Thin Silicon Passivation Film Deposited prior to Phosphorous Diffusion

Directory of Open Access Journals (Sweden)

Ching-Tao Li

2014-01-01

Full Text Available We demonstrate the performance improvement of p-type single-crystalline silicon (sc-Si solar cells resulting from front surface passivation by a thin amorphous silicon (a-Si film deposited prior to phosphorus diffusion. The conversion efficiency was improved for the sample with an a-Si film of ~5 nm thickness deposited on the front surface prior to high-temperature phosphorus diffusion, with respect to the samples with an a-Si film deposited on the front surface after phosphorus diffusion. The improvement in conversion efficiency is 0.4% absolute with respect to a-Si film passivated cells, that is, the cells with an a-Si film deposited on the front surface after phosphorus diffusion. The new technique provided a 0.5% improvement in conversion efficiency compared to the cells without a-Si passivation. Such performance improvements result from reduced surface recombination as well as lowered contact resistance, the latter of which induces a high fill factor of the solar cell.

Solar thermal heating and cooling. A bibliography with abstracts

Science.gov (United States)

Arenson, M.

1979-01-01

This bibliographic series cites and abstracts the literature and technical papers on the heating and cooling of buildings with solar thermal energy. Over 650 citations are arranged in the following categories: space heating and cooling systems; space heating and cooling models; building energy conservation; architectural considerations, thermal load computations; thermal load measurements, domestic hot water, solar and atmospheric radiation, swimming pools; and economics.

Semi-transparent solar energy thermal storage device

Science.gov (United States)

McClelland, John F.

1985-06-18

A visually transmitting solar energy absorbing thermal storage module includes a thermal storage liquid containment chamber defined by an interior solar absorber panel, an exterior transparent panel having a heat mirror surface substantially covering the exterior surface thereof and associated top, bottom and side walls, Evaporation of the thermal storage liquid is controlled by a low vapor pressure liquid layer that floats on and seals the top surface of the liquid. Porous filter plugs are placed in filler holes of the module. An algicide and a chelating compound are added to the liquid to control biological and chemical activity while retaining visual clarity. A plurality of modules may be supported in stacked relation by a support frame to form a thermal storage wall structure.

Sol–gel derived solar selective coatings on SS 321 substrates for solar thermal applications

Energy Technology Data Exchange (ETDEWEB)

Subasri, R., E-mail: subasri@arci.res.in; Soma Raju, K.R.C.; Reddy, D.S.; Hebalkar, Neha Y.; Padmanabham, G.

2016-01-01

Sol–gel derived multilayered solar selective coatings were generated on AISI SS 321 substrates using Ag-TiO{sub 2} as the cermet layer, titania and silica as the dielectric layers with high and low refractive indices respectively. The phase compositions of the individual layers were independently confirmed using grazing angle incidence X-ray diffraction, which was corroborated by X-ray photoelectron spectroscopic analysis. Thickness of the layers was measured using variable angle spectroscopic ellipsometry. The solar absorbance was measured over the UV–Vis-NIR wavelength range. Thermal emissivity was determined using FTIR spectroscopic analysis. The durability of the coatings was ascertained using accelerated corrosion testing methods as well as by measuring the optical properties after thermal cycling experiments. The promising nature of hexavalent chrome-free, environmental friendly, multilayered solar selective coating was ascertained with respect to amenability to scale-up. - Highlights: • Sol–gel derived multilayered solar selective coatings developed on SS321 • Solar absorptance and thermal emittance at par with toxic chrome coating • Thermal stability and corrosion resistance of coatings studied • Coating performance found to be promising for large scale applications • Scale-up amenability investigated by coating generation on 1 m tubes.

Sol–gel derived solar selective coatings on SS 321 substrates for solar thermal applications

International Nuclear Information System (INIS)

Subasri, R.; Soma Raju, K.R.C.; Reddy, D.S.; Hebalkar, Neha Y.; Padmanabham, G.

2016-01-01

Sol–gel derived multilayered solar selective coatings were generated on AISI SS 321 substrates using Ag-TiO_2 as the cermet layer, titania and silica as the dielectric layers with high and low refractive indices respectively. The phase compositions of the individual layers were independently confirmed using grazing angle incidence X-ray diffraction, which was corroborated by X-ray photoelectron spectroscopic analysis. Thickness of the layers was measured using variable angle spectroscopic ellipsometry. The solar absorbance was measured over the UV–Vis-NIR wavelength range. Thermal emissivity was determined using FTIR spectroscopic analysis. The durability of the coatings was ascertained using accelerated corrosion testing methods as well as by measuring the optical properties after thermal cycling experiments. The promising nature of hexavalent chrome-free, environmental friendly, multilayered solar selective coating was ascertained with respect to amenability to scale-up. - Highlights: • Sol–gel derived multilayered solar selective coatings developed on SS321 • Solar absorptance and thermal emittance at par with toxic chrome coating • Thermal stability and corrosion resistance of coatings studied • Coating performance found to be promising for large scale applications • Scale-up amenability investigated by coating generation on 1 m tubes

Solar thermal power system

Science.gov (United States)

Bennett, Charles L.

2010-06-15

A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

SolarOil Project, Phase I preliminary design report. [Solar Thermal Enhanced Oil Recovery project

Energy Technology Data Exchange (ETDEWEB)

Baccaglini, G.; Bass, J.; Neill, J.; Nicolayeff, V.; Openshaw, F.

1980-03-01

The preliminary design of the Solar Thermal Enhanced Oil Recovery (SolarOil) Plant is described in this document. This plant is designed to demonstrate that using solar thermal energy is technically feasible and economically viable in enhanced oil recovery (EOR). The SolarOil Plant uses the fixed mirror solar concentrator (FMSC) to heat high thermal capacity oil (MCS-2046) to 322/sup 0/C (611/sup 0/F). The hot fluid is pumped from a hot oil storage tank (20 min capacity) through a once-through steam generator which produces 4.8 MPa (700 psi) steam at 80% quality. The plant net output, averaged over 24 hr/day for 365 days/yr, is equivalent to that of a 2.4 MW (8.33 x 10/sup 6/ Btu/hr) oil-fired steam generator having an 86% availability. The net plant efficiency is 57.3% at equinox noon, a 30%/yr average. The plant will be demonstrated at an oilfield site near Oildale, California.

Thermally-Induced Structural Disturbances of Rigid Panel Solar Arrays

Science.gov (United States)

Johnston, John D.; Thornton, Earl A.

1997-01-01

The performance of a significant number of spacecraft has been impacted negatively by attitude disturbances resulting from thermally-induced motions of flexible structures. Recent examples of spacecraft affected by these disturbances include the Hubble Space Telescope (HST) and the Upper Atmosphere Research Satellite (UARS). Thermally-induced structural disturbances occur as the result of rapid changes in thermal loading typically initiated as a satellite exits or enters the Earth's shadow. Temperature differences in flexible appendages give rise to structural deformations, which in turn result in disturbance torques reacting back on the spacecraft. Structures which have proven susceptible to these disturbances include deployable booms and solar arrays. This paper investigates disturbances resulting from thermally-induced deformations of rigid panel solar arrays. An analytical model for the thermal-structural response of the solar array and the corresponding disturbance torque are presented. The effect of these disturbances on the attitude dynamics of a simple spacecraft is then investigated using a coupled system of governing equations which includes the effects of thermally-induced deformations. Numerical results demonstrate the effect of varying solar array geometry on the dynamic response of the system.

Cheap effective thermal solar-energy collectors

Energy Technology Data Exchange (ETDEWEB)

Highgate, D.J.; Probert, S.D. [Cranfield University, Bedford (United Kingdom). Dept. of Applied Energy

1996-04-01

A light-weight flexible solar-collector, with a wavelength-selective absorption surface and an insolation-transparent thermal-insulation protecter for its aperture, was built and tested. Its cheapness and high performance, relative to a conventional flat-plate solar-collector, provide a prima-facie case for the more widespread adoption of its design. (author)

Solar cells based upon multicrystalline Si with DLC antireflection and passivating coatings

International Nuclear Information System (INIS)

Klyui, N.; Litovchenko, V.; Neselevska, L.; Kostylyov, V.; Sarikov, A.; Taraschenko, N.; Kittler, M.; Seifert, W.

2006-01-01

The characteristics of multicrystalline Si solar cells covered by diamond-like carbon (DLC) antireflection coatings been experimentally studied. It has been shown that this kind of coating provides a significant increase of the efficiency of solar cells mainly due to the increase of the short-circuit current density. The effects of antireflection and of the surface and bulk passivation on the SC current-voltage characteristics due to the DLC deposition have been investigated theoretically. Physical mechanisms underlying the observed effects have been proposed

The role of Solar thermal in Future Energy Systems

DEFF Research Database (Denmark)

Mathiesen, Brian Vad; Hansen, Kenneth

This report deals with solar thermal technologies and investigates possible roles for solar thermal in future energy systems for four national energy systems; Germany, Austria, Italy and Denmark. The project period started in January 2014 and finished by October 2017. This report is based...

Interreg IIIA SR - AT project SOLARSTRAT. Results of the interviews with experts on solar-thermal energy utilization. Possibilities of support to thermal-solar systems installation

International Nuclear Information System (INIS)

Ilias, I.

2005-01-01

In this presentation author presented the results of collecting of important data for solar-thermal market scenario modelling through interviews with Slovak stakeholders. Interviews with Slovak experts on thermal-solar energy utilisation represents important project activity in order to give a general review of current status of the market in target Bratislava region and to collect important data for next market analyses, which will be prepared by Austrian partner - IFAST. The results of face-to-face interviews and filled questionnaires can be generally presented as follows: - public attitude towards the renewable energy sources and solar energy utilisation is slowly getting better in Slovakia; - evaluating public awareness only 15% share of population is able to consider the possibilities of thermal-solar technologies; - expected increase of fossil fuels and energy prices will help to spread of thermal-solar systems through shorten the pay-back period of investment while prices of thermal-solar systems will increase only slightly; - also expected increase of political and economic public awareness about energy production and demand on thermal-solar systems will help to promote the further development of solar energy utilisation in Slovakia. Respondents were also evaluating the main barriers for better solar energy utilisation: (1) Weak public awareness, no systematic information campaign (examples from real life); (2) Missing support to installation for physical persons, no tax allowances; (3) High investment costs; (4) Unfriendly legislation. Other important barriers for better development of the sector were presented. E.g. assembling companies cannot afford effective promotion, only big producers are able to fund the marketing on their products, which are mainly expensive systems. Public is still considering solar systems as too expensive ('I can't afford it'). Renewable energy sources (RES) are often presented as the alternative to nuclear energy - this

Interreg IIIA SR - AT project SOLARSTRAT. Results of the interviews with experts on solar-thermal energy utilization. Possibilities of support to thermal-solar systems installation

International Nuclear Information System (INIS)

Ilias, I.

2005-01-01

In this presentation author presented the results of collecting of important data for solar-thermal market scenario modelling through interviews with Slovak stakeholders. Interviews with Slovak experts on thermal-solar energy utilisation represents important project activity in order to give a general review of current status of the market in target Bratislava region and to collect important data for next market analyses, which will be prepared by Austrian partner - IFAST. The results of face-to-face interviews and filled questionnaires can be generally presented as follows: - public attitude towards the renewable energy sources and solar energy utilisation is slowly getting better in Slovakia; - evaluating public awareness only 15% share of population is able to consider the possibilities of thermal-solar technologies; - expected increase of fossil fuels and energy prices will help to spread of thermal-solar systems through shorten the pay-back period of investment while prices of thermal-solar systems will increase only slightly; - also expected increase of political and economic public awareness about energy production and demand on thermal-solar systems will help to promote the further development of solar energy utilisation in Slovakia. Respondent were also evaluating the main barriers for better solar energy utilisation: (1) Weak public awareness, no systematic information campaign (examples from real life); (2) Missing support to installation for physical persons, no tax allowances; (3) High investment costs; (4) Unfriendly legislation Other important barriers for better development of the sector were presented. E.g. assembling companies cannot afford effective promotion, only big producers are able to fund the marketing on their products, which are mainly expensive systems. Public is still considering solar systems as too expensive ('I can't afford it'). Renewable energy sources (RES) are often presented as the alternative to nuclear energy - this argument

Positioning Your Library for Solar (and Financial) Gain. Improving Energy Efficiency, Lighting, and Ventilation with Primarily Passive Techniques

Science.gov (United States)

Shane, Jackie

2012-01-01

This article stresses the importance of building design above technology as a relatively inexpensive way to reduce energy costs for a library. Emphasis is placed on passive solar design for heat and daylighting, but also examines passive ventilation and cooling, green roofs, and building materials. Passive design is weighed against technologies…

Robust optimization of a tandem grating solar thermal absorber

Science.gov (United States)

Choi, Jongin; Kim, Mingeon; Kang, Kyeonghwan; Lee, Ikjin; Lee, Bong Jae

2018-04-01

Ideal solar thermal absorbers need to have a high value of the spectral absorptance in the broad solar spectrum to utilize the solar radiation effectively. Majority of recent studies about solar thermal absorbers focus on achieving nearly perfect absorption using nanostructures, whose characteristic dimension is smaller than the wavelength of sunlight. However, precise fabrication of such nanostructures is not easy in reality; that is, unavoidable errors always occur to some extent in the dimension of fabricated nanostructures, causing an undesirable deviation of the absorption performance between the designed structure and the actually fabricated one. In order to minimize the variation in the solar absorptance due to the fabrication error, the robust optimization can be performed during the design process. However, the optimization of solar thermal absorber considering all design variables often requires tremendous computational costs to find an optimum combination of design variables with the robustness as well as the high performance. To achieve this goal, we apply the robust optimization using the Kriging method and the genetic algorithm for designing a tandem grating solar absorber. By constructing a surrogate model through the Kriging method, computational cost can be substantially reduced because exact calculation of the performance for every combination of variables is not necessary. Using the surrogate model and the genetic algorithm, we successfully design an effective solar thermal absorber exhibiting a low-level of performance degradation due to the fabrication uncertainty of design variables.

Efficient Solar-Thermal Energy Harvest Driven by Interfacial Plasmonic Heating-Assisted Evaporation.

Science.gov (United States)

Chang, Chao; Yang, Chao; Liu, Yanming; Tao, Peng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Deng, Tao

2016-09-07

The plasmonic heating effect of noble nanoparticles has recently received tremendous attention for various important applications. Herein, we report the utilization of interfacial plasmonic heating-assisted evaporation for efficient and facile solar-thermal energy harvest. An airlaid paper-supported gold nanoparticle thin film was placed at the thermal energy conversion region within a sealed chamber to convert solar energy into thermal energy. The generated thermal energy instantly vaporizes the water underneath into hot vapors that quickly diffuse to the thermal energy release region of the chamber to condense into liquids and release the collected thermal energy. The condensed water automatically flows back to the thermal energy conversion region under the capillary force from the hydrophilic copper mesh. Such an approach simultaneously realizes efficient solar-to-thermal energy conversion and rapid transportation of converted thermal energy to target application terminals. Compared to conventional external photothermal conversion design, the solar-thermal harvesting device driven by the internal plasmonic heating effect has reduced the overall thermal resistance by more than 50% and has demonstrated more than 25% improvement of solar water heating efficiency.

The influence of weather on the thermal performance of solar heating systems

DEFF Research Database (Denmark)

Andersen, Elsa; Furbo, Simon; Shah, Louise Jivan

2003-01-01

. The investigation is based on calculations with validated models. Solar heating systems with different solar collector types, heat storage volumes and solar fractions are included in the investigation. The yearly solar radiation varies with approximately 20 % in the period from 1990 until 2002. The calculations......The influence of weather on the thermal performance of solar combi systems, solar domestic hot water systems and solar heating plants is investigated. The investigation is based on weather data from the Danish Design Reference Year, DRY and weather data measured for a period from 1990 until 2002...... show that the thermal performance of the investigated systems varies due to the weather variation. The variation of the yearly thermal performance of a solar heating plant is about 40 % while the variation of the yearly thermal performance of a solar domestic hot water system is about 30...

Value and cost analyses for solar thermal-storage systems

Energy Technology Data Exchange (ETDEWEB)

Luft, W.; Copeland, R.J.

1983-04-01

Value and cost data for thermal energy storage are presented for solar thermal central receiver systems for which thermal energy storage appears to be attractive. Both solar thermal electric power and industrial process heat applications are evaluated. The value of storage is based on the cost for fossil fuel and solar thermal collector systems in 1990. The costing uses a standard lifetime methodology with the storage capacity as a parameter. Both value and costs are functions of storage capacity. However, the value function depends on the application. Value/cost analyses for first-generation storage concepts for five central receiver systems (molten salt, water/steam, organic fluid, air, and liquid metal) established the reference against which new systems were compared. Some promising second-generation energy storage concepts have been identified, and some more advanced concepts have also been evaluated.

Study on the use of TiO2 passivation layer to reduce recombination losses in dye sensitized solar cells

International Nuclear Information System (INIS)

Eskander bin Samsudin, Adel; Mohamed, Norani Muti; Nayan, Nafarizal; Ali, Riyaz Ahmad Mohamed; Shariffuddin, Sharifah Amira Amir; Omar, Salwa

2012-01-01

A lot of research on various aspects of dye solar cells (DSC) has been carried out in order to improve efficiency. This paper analyzes the utilization of TiO 2 passivation layers of different thicknesses by improving the electron transport properties. Four different thicknesses of passivation layers namely 10, 20, 50 and 100 nm were deposited onto the working electrode using r.f sputtering. The electrodes were assembled into TiO 2 based DSC with active area of 1 cm 2 . The solar performance was investigated using 100 mW/cm 2 of AM 1.5 simulated sunlight from solar simulator. The kinetics of the solar cells was investigated using Electrochemical Impedance Spectroscopy (EIS) measurement and the spectral response was measured using Incident Photon to Electron Conversion (IPCE) measurement system. The highest efficiency was found for DSC with 20 nm passivation layer. DSCs with the passivation layer have open circuit voltage, V OC increased by 57 mV, their current density, J SC increased by 0.774 mA cm −2 compared to the one without the passivation layer. The quantum efficiency of the 20 nm passivation layer is the highest, peaking at the wavelength of 534 nm, resulting in the highest performance. All DSCs with the passivation layer recorded higher ratio of R BR /R T where R T is the diffusion resistance of the TiO 2 particles in the mesoscopic layer and R BR is the recombination resistance of the electron to the electrolyte. This implies that the recombination of the electrolyte I − 3 /3I − couple at the substrate/electrolyte interface has been effectively reduced resulting in an enhanced efficiency.

Amorphous silicon passivation for 23.3% laser processed back contact solar cells

Science.gov (United States)

Carstens, Kai; Dahlinger, Morris; Hoffmann, Erik; Zapf-Gottwick, Renate; Werner, Jürgen H.

2017-08-01

This paper presents amorphous silicon deposited at temperatures below 200 °C, leading to an excellent passivation layer for boron doped emitter and phosphorus doped back surface field areas in interdigitated back contact solar cells. A higher deposition temperature degrades the passivation of the boron emitter by an increased hydrogen effusion due to lower silicon hydrogen bond energy, proved by hydrogen effusion measurements. The high boron surface doping in crystalline silicon causes a band bending in the amorphous silicon. Under these conditions, at the interface, the intentionally undoped amorphous silicon becomes p-type conducting, with the consequence of an increased dangling bond defect density. For bulk amorphous silicon this effect is described by the defect pool model. We demonstrate, that the defect pool model is also applicable to the interface between amorphous and crystalline silicon. Our simulation shows the shift of the Fermi energy towards the valence band edge to be more pronounced for high temperature deposited amorphous silicon having a small bandgap. Application of optimized amorphous silicon as passivation layer for the boron doped emitter and phosphorus doped back surface field on the rear side of laser processed back contact solar cells, fabricated using four laser processing steps, yields an efficiency of 23.3%.

Simulation on the Performance of Dye Solar Cell Incorporated with TiO2 Passivation Layer

Directory of Open Access Journals (Sweden)

Unan Yusmaniar Oktiawati

2016-01-01

Full Text Available Dye Solar Cell (DSC has started to gain interest in the recent years for practical application because of its ecofriendly, low cost, and easy fabrication. However, its efficiency is still not as competitive as the conventional silicon based solar cell. One of the research efforts to improve the efficiency of DSC is to use the passivation layer in between the photoelectrode material and the conductive oxide substrate. Thus, the objective of this simulation study is to investigate the effect of passivation layer on the performance of DSC. Properties from literatures which are based on physical work were captured as the input for the simulation using process, ATHENA, and device, ATLAS, simulator. Results have shown that the addition of two-20 nm TiO2 passivation layers on DSC can enhance the efficiency by 11% as the result of less recombination, higher electron mobility, and longer electron lifetime.

Extraction of thermal Green's function using diffuse fields: a passive approach applied to thermography

Science.gov (United States)

Capriotti, Margherita; Sternini, Simone; Lanza di Scalea, Francesco; Mariani, Stefano

2016-04-01

In the field of non-destructive evaluation, defect detection and visualization can be performed exploiting different techniques relying either on an active or a passive approach. In the following paper the passive technique is investigated due to its numerous advantages and its application to thermography is explored. In previous works, it has been shown that it is possible to reconstruct the Green's function between any pair of points of a sensing grid by using noise originated from diffuse fields in acoustic environments. The extraction of the Green's function can be achieved by cross-correlating these random recorded waves. Averaging, filtering and length of the measured signals play an important role in this process. This concept is here applied in an NDE perspective utilizing thermal fluctuations present on structural materials. Temperature variations interacting with thermal properties of the specimen allow for the characterization of the material and its health condition. The exploitation of the thermographic image resolution as a dense grid of sensors constitutes the basic idea underlying passive thermography. Particular attention will be placed on the creation of a proper diffuse thermal field, studying the number, placement and excitation signal of heat sources. Results from numerical simulations will be presented to assess the capabilities and performances of the passive thermal technique devoted to defect detection and imaging of structural components.

Economic impact of solar thermal electricity deployment in Spain

International Nuclear Information System (INIS)

Caldes, N.; Varela, M.; Santamaria, M.; Saez, R.

2009-01-01

The objective of the work is to estimate the socio-economic impacts of increasing the installed solar thermal energy power capacity in Spain. Using an input-output (I-O) analysis, this paper estimates the increase in the demand for goods and services as well as in employment derived from solar thermal plants in Spain under two different scenarios: (a) based on two solar thermal power plants currently in operation (with 50 and 17 MW of installed capacity); (b) the compliance to the Spanish Renewable Energy Plan (PER) 2005-2010 reaching 500 MW by 2010. Results show that the multiplier effect of the PER is 2.3 and the total employment generated would reach 108,992 equivalent full-time jobs of 1 year of duration. Despite this is an aggregated result, this figure represents 4.5% of current Spanish unemployment. It can be concluded that the socio-economic effect of the PER's solar thermal installed capacity goal would be remarkable.

Solar chimney integrated with passive evaporative cooler applied on glazing surfaces

International Nuclear Information System (INIS)

Al Touma, Albert; Ghali, Kamel; Ghaddar, Nesreen; Ismail, Nagham

2016-01-01

This study investigates the performance of a hybrid system applied on glazing surfaces for reducing the space cooling load and radiation asymmetry. The proposed system combines the principles of passive evaporative cooling with the natural buoyant flow in solar chimneys to entrain outdoor air and attenuate the window surface temperature. A predictive heat and mass transport model combining the evaporative cooler, glazing section, solar chimney and an office space is developed to study the system performance in harshly hot climates. The developed model was validated through experiments conducted in a twin climatic chamber for given ambient temperature, humidity, and solar radiation conditions. Good agreement was found between the measured and the predicted window temperatures and space loads at maximum discrepancy lower than 4.3%. The proposed system is applied to a typical office space to analyze its effectiveness in reducing the window temperature, the space load and radiation asymmetry, while maintaining the indoor comfort conditions. Results have shown that the system is reduced the space load by −19.8% and attenuated the radiation asymmetry significantly for office spaces having window-to-wall ratio of 40% in climate of Riyadh, KSA. The system performance diminished when applied in locations suffering from humid weather climates. - Highlights: • A passive evaporative-cooled solar chimney system is introduced to decrease window temperature. • A mathematical model is developed of the system to predict induce air flow and window surface temperature. • The model is validated with experiments in twin room climatic chamber and using artificial solar lamps. • The system reduces window maximum temperature by 5 °C in the hot dry climate of Riyadh, KSA. • It reduced the space load by 19.4% for office spaces at window-to-wall ratio of 40% in Riyadh, KSA.

Development of space heating and domestic hot water systems with compact thermal energy storage. Compact thermal energy storage: Material development for System Integration

NARCIS (Netherlands)

Davidson, J.H.; Quinnell, J.; Burch, J.; Zondag, H.A.; Boer, R. de; Finck, C.J.; Cuypers, R.; Cabeza, L.F.; Heinz, A.; Jahnig, D.; Furbo, S.; Bertsch, F.

2013-01-01

Long-term, compact thermal energy storage (TES) is essential to the development of cost-effective solar and passive building-integrated space heating systems and may enhance the annual technical and economic performance of solar domestic hot water (DHW) systems. Systems should provide high energy

Solar thermal barometer. More than 2 million m2 installed in 2005

International Nuclear Information System (INIS)

Anon.

2006-01-01

With 22,8% growth, the european union solar thermal market (glazed, vacuum and unglazed collectors) has passed the 2 million m 2 benchmark corresponding to installed capacity of approximately 1450 MWth. This growth can be explained by the very good performance of the three leading EU solar thermal markets: Germany, Austria and Greece and the increase in importance of the French and Spanish markets. Statistical data are provided for the european union on the annually installed surfaces, breakdown by technologies of the solar thermal market, the solar thermal capacity in operation, the representative companies of the thermal solar sector and a comparison of current trend with the white book objectives. (A.L.B.)

4. meeting on passive solar energy houses. Proceedings; 4. Passivhaus Tagung. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

Feist, W [ed.; Sariri, V; Nagel, M [comps.; Passivhaus Institut, Darmstadt (Germany)

2000-03-01

This is the report on the 4th Passive Building Conference, which took place at Kassel on March 10/11, 2000. There were eight sections: (a) Planners' workshop; (b) Architecture; (c) Ventilation; (d) Construction practice; (e) Subjective users' comfort and measured results; (f) Practical implementation; (g) economic and ecological assessment; (h) Solar architecture; (i) Heat supply. It was considered particularly favourable that passive solar buildings do not only offer a solution to ecological problems but also a growing market. [German] Der Tagungsband der '4. Passivhaus Tagung', die von 10. bis 11. Maerz 2000 in Kassel stattgefunden hat, beinhalten Beitraege, die in acht Arbeitsgruppen vorgetragen worden: (a) Planer-Werkstatt; (b) Architektur; (c) Lueftungsplanung; (d) Baupraxis; (e) Wohnerfahrung, Messergebnisse; (f) Umsetzung; (g) oekonomische und oekologische Bewertung; (h) Solararchitektur; (i) Waermeversorgung. Es wird vom Herausgeber als besonders erfreulich herausgestellt, dass durch eine erfolgreiche Passivhaus-Entwicklung neben der Loesung der Klimaprobleme zugleich ein neuer Wachstumsmarkt geschaffen werde, der mit einer Mehrung von Wertschoepfung und Wohlstand verbunden ist. (AKF)

The development of a volumetric solar thermal receiver: an overview

International Nuclear Information System (INIS)

Sagie, D.

1996-01-01

Solar energy has received much interest in recent years, being a clean (free of pollution or other environmental damage) and inexhaustible energy source. It is also considered safer than some other non conventional energy sources (like nuclear energy). The interest in solar energy is motivated mainly by the growing awareness of the environmental problems associated with the use of conventional fuels. However, solar energy may become a serious alternative only if it can be used efficiently in major energy consuming industries (like the chemical industry), or be used for electricity generation. Those facilities are nowadays solely dependent on fossil fuels as the prime source of energy. The solar energy, reaching the earth in the form of radiation, can be utilized either by direct quantum conversion using photo-voltaic solar cells, or by converting the radiation into thermal energy, to be used directly for heating, or to feed a thermal to electric converting cycle. After three decades of huge spending on the development of photo-voltaic systems those devices are commercially competitive only on a very small energy scale, while solar thermal commercial applications are more attractive. Prominent examples are the domestic heating water receivers (direct thermal), and LUZ International electricity generation plants which are currently operated on a commercial basis, supplying 80 MWe per plant. Direct thermal exploitation of solar energy is naturally more efficient than converting to electricity, but is limited to specific applications and locations especially since thermal storage at high temperature is not commercially viable. Efficient electricity production at a competitive price is clearly the biggest opportunity for solar energy . (author)

Solar thermal and concentrated solar power barometer - EurObserv'ER - May 2012

International Nuclear Information System (INIS)

2012-05-01

27545 MWth: the EU's solar thermal base to date at the end of 2011. After two years of sharp decline, the European solar thermal market is bottoming out. The EurObserv'ER survey findings are that the installation figure fell just 1.9% in comparison with 2010, giving a newly-installed collector area of 3.7 million m 2 . The concentrated solar power sector has been forging ahead alongside the heat production applications, and at the end of 2011 installed capacity passed the one gigawatt mark in Spain for the first time with 1157.2 MWe

Effect of low thermal budget annealing on surface passivation of silicon by ALD based aluminum oxide films.

Science.gov (United States)

Vandana; Batra, Neha; Gope, Jhuma; Singh, Rajbir; Panigrahi, Jagannath; Tyagi, Sanjay; Pathi, P; Srivastava, S K; Rauthan, C M S; Singh, P K

2014-10-21

Thermal ALD deposited Al2O3 films on silicon show a marked difference in surface passivation quality as a function of annealing time (using a rapid thermal process). An effective and quality passivation is realized in short anneal duration (∼100 s) in nitrogen ambient which is reflected in the low surface recombination velocity (SRV passivation. Both as-deposited and low thermal budget annealed films show the presence of positive fixed charges and this is never been reported in the literature before. The role of field and chemical passivation is investigated in terms of fixed charge and interface defect densities. Further, the importance of the annealing step sequence in the MIS structure fabrication protocol is also investigated from the view point of its effect on the nature of fixed charges.

estec2007 - 3rd European solar thermal energy conference. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-12-14

The sessions of the 'estec2007 - 3{sup rd} European Solar Thermal Energy Conference held in Freiburg, Germany have the following titles: The solar thermal sector at a turning point; Cooling and Process Heat, Country reports Europe; Standards and Certification; Country reports outside Europe; Awareness raising and marketing; Domestic hot water and space heating; Domestic hot water and space heating; Quality Assurance and Solar Thermal Energy Service Companies; Collectors and other key technical issues; Policy - Financial incentives; Country Reports; Marketing and Awareness Raising; Quality Assurance Measures/Monistoring; Standards and Certification; Collectors; Domestic Hot Water and Space Heating; Industrial Process Heat; Storage; Solar Cooling. (AKF)

estec2007 - 3rd European solar thermal energy conference. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-12-14

The sessions of the 'estec2007 - 3{sup rd} European Solar Thermal Energy Conference held in Freiburg, Germany have the following titles: The solar thermal sector at a turning point; Cooling and Process Heat, Country reports Europe; Standards and Certification; Country reports outside Europe; Awareness raising and marketing; Domestic hot water and space heating; Domestic hot water and space heating; Quality Assurance and Solar Thermal Energy Service Companies; Collectors and other key technical issues; Policy - Financial incentives; Country Reports; Marketing and Awareness Raising; Quality Assurance Measures/Monistoring; Standards and Certification; Collectors; Domestic Hot Water and Space Heating; Industrial Process Heat; Storage; Solar Cooling. (AKF)

Energetic and exergetic performances analysis of a PV/T (photovoltaic thermal) solar system tested and simulated under to Tunisian (North Africa) climatic conditions

International Nuclear Information System (INIS)

Hazami, Majdi; Riahi, Ali; Mehdaoui, Farah; Nouicer, Omeima; Farhat, Abdelhamid

2016-01-01

The endeavor of this paper is to study the potential offered by the expenditure of a PV/T (photovoltaic thermal) solar system in Tunisian households. This investigation is performed according to two-folded approaches. Firstly, outdoor experiments were carried out during July 2014 for both passive and active mode. An exhaustive energy and exergy analysis was then performed to evaluate the instantaneous thermal and the electrical exergy outputs of the PV/T solar system. The results showed that the maximum instantaneous thermal and electric energy efficiency in active mode are about 50 and 15%, respectively. It was found also that the maximum thermal and electric exergy efficiencies were about 50 and 14.8%, respectively. The second approach is the evaluation of the monthly/annual performances of the PV/T solar system under typical climate area of Tunisia by using TRNSYS program. The results showed that the active mode enhances the electric efficiency and the exergy of the PV/T system by 3 and 2.5% points, respectively. The results showed that the optimized PV/T solar system covert the major part of the hot water and the electric needs of Tunisian household's with an expected annual average gain of about 14.60 and 5.33%, respectively. An economic appraisal was performed. - Highlights: • The present work studies the potential of using PV/T solar collector in Tunisian. • The maximum thermal and electric efficiencies are 50 and 15%, respectively. • The maximum thermal and electric exergy efficiencies were 50 and 14.8%. • The results showed that the expected annual gain are 14.60 and 5.33%. • The PV/T is compared to a high quality commercial solar collectors and a PV panel.

Passive residual energy utilization system in thermal cycles on water-cooled power reactors

International Nuclear Information System (INIS)

Placco, Guilherme M.; Guimaraes, Lamartine N.F.; Santos, Rubens S. dos

2013-01-01

This work presents a concept of a residual energy utilization in nuclear plants thermal cycles. After taking notice of the causes of the Fukushima nuclear plant accident, an idea arose to adapt a passive thermal circuit as part of the ECCS (Emergency Core Cooling System). One of the research topics of IEAv (Institute for Advanced Studies), as part of the heat conversion of a space nuclear power system is a passive multi fluid turbine. One of the main characteristics of this device is its passive capability of staying inert and be brought to power at moments notice. During the first experiments and testing of this passive device, it became clear that any small amount of gas flow would generate power. Given that in the first stages of the Fukushima accident and even during the whole event there was plenty availability of steam flow that would be the proper condition to make the proposed system to work. This system starts in case of failure of the ECCS, including loss of site power, loss of diesel generators and loss of the battery power. This system does not requires electricity to run and will work with bleed steam. It will generate enough power to supply the plant safety system avoiding overheating of the reactor core produced by the decay heat. This passive system uses a modified Tesla type turbine. With the tests conducted until now, it is possible to ensure that the operation of this new turbine in a thermal cycle is very satisfactory and it performs as expected. (author)

Passive and hybrid solar technologies program summary

Science.gov (United States)

1985-05-01

The goal of the national energy policy is to foster an adequate supply of energy at reasonable prices. This policy recognizes that adequate supply requires flexibility, with no undue reliance on any single source of supply. The goal of reasonable prices suggests economic efficiency so that consumers, individuals, commercial and industrial users alike, are not penalized by government regulation or subside. The strategies for achieving this energy policy goal are: (1) to minimize federal regulation in energy pricing while maintaining public health and safety and environmental quality, and (2) to promote a balanced and mixed energy resource system through research and development. One of the keys to energy sufficiently is the scientific application of passive solar energy techniques.

Performance analysis of a lunar based solar thermal power system with regolith thermal storage

International Nuclear Information System (INIS)

Lu, Xiaochen; Ma, Rong; Wang, Chao; Yao, Wei

2016-01-01

The manned deep-space exploration is a hot topic of the current space activities. The continuous supply of thermal and electrical energy for the scientific equipment and human beings is a crucial issue for the lunar outposts. Since the night lasts for periods of about 350 h at most locations on the lunar surface, massive energy storage is required for continuous energy supply during the lengthy lunar night and the in-situ resource utilization is demanded. A lunar based solar thermal power system with regolith thermal storage is presented in this paper. The performance analysis is carried out by the finite-time thermodynamics to take into account major irreversible losses. The influences of some key design parameters are analyzed for system optimization. The analytical results shows that the lunar based solar thermal power system with regolith thermal storage can meet the requirement of the continuous energy supply for lunar outposts. - Highlights: • A lunar based solar thermal power system with regolith thermal storage is presented. • The performance analysis is carried out by the finite-time thermodynamics. • The influences of some key design parameters are analyzed.

High-performance flat-panel solar thermoelectric generators with high thermal concentration

Science.gov (United States)

Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J. Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

2011-07-01

The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m-2) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity.

High-performance flat-panel solar thermoelectric generators with high thermal concentration.

Science.gov (United States)

Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

2011-05-01

The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m(-2)) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity. © 2011 Macmillan Publishers Limited. All rights reserved

Economic Feasibility and Market Readiness of Solar Technologies. Draft Final Report. Volume I.

Energy Technology Data Exchange (ETDEWEB)

Flaim, Silvio J.; Buchanan, Deborah L.; Christmas, Susan; Fellhauer, Cheryl; Glenn, Barbara; Ketels, Peter A.; Levary, Arnon; Mourning, Pete; Steggerda, Paul; Trivedi, Harit; Witholder, Robert E.

1978-09-01

Systems descriptions, costs, technical and market readiness assessments are reported for ten solar technologies: solar heating and cooling of buildings (SHACOB), passive, agricultural and industrial process heat (A/IPH), biomass, ocean thermal (OTEC), wind (WECS), solar thermal electric, photovoltaics, satellite power station (SPS), and solar total energy systems (STES). Study objectives, scope, and methods. are presented. of Joint Task The cost and market analyses portion 5213/6103 will be used to make commercialization assessments in the conclusions of. the final report.

Materials research for passive solar systems: Solid-state phase-change materials

Science.gov (United States)

Benson, D. K.; Webb, J. D.; Burrows, R. W.; McFadden, J. D. O.; Christensen, C.

1985-03-01

A set of solid-state phase-change materials is being evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol (C5H12O4), pentaglycerinve (C5H12O3), and neopentyl glycol (C5H12O2). Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature between 25 C and 188 C, and have latent heats of transformation etween 20 and 70 cal/g. Transformation temperatures, specific heats, and latent heats of transformation have been measured for a number of these materials. Limited cyclic experiments suggest that the solid solutions are stable. These phase-change materials exhibit large amounts of undercooling; however, the addition of certain nucleating agents as particulate dispersions in the solid phase-change material greatly reduces this effect. Computer simulations suggest that the use of an optimized solid-state phase-change material in a Trombe wall could provide better performance than a concrete Trombe wall four times thicker and nine times heavier.

Myo-inositol based nano-PCM for solar thermal energy storage

International Nuclear Information System (INIS)

Singh, D.K.; Suresh, S.; Singh, H.; Rose, B.A.J.; Tassou, S.; Anantharaman, N.

2017-01-01

Highlights: • Properties of Myo-Inositol laden with Al_2O_3 and CuO nanoparticles was studied. • The melting point was found to increase for MI-A and decrease for MI-C. • MI interacted only physically on addition of NPs. • Mass changes were <3% after thermal cycling of MI-A and MI-C. • MI-A is more suited for thermal energy storage than MI-C. - Abstract: The thermo-physical behavior of Myo-Inositol (MI), (a sugar alcohol), was investigated as a potential material for developing more compact solar thermal energy storage systems than those currently available. This latent heat storage medium could be utilized for commercial and industrial applications using solar thermal energy storage in the temperature range of 160–260 °C, if its thermal performance was modified. The objective of this investigation was to determine via experimentation, if Al_2O_3 and CuO nanoparticles dispersed in pure MI for mixtures of 1, 2 and 3% (by weight) improved the thermal performance of MI for solar thermal energy systems. Nanoparticles only physically interacted with MI, and not chemically, even after 50 thermal cycles. The distribution of CuO nanoparticles in the nano-PCM was found to be more uniform than alumina nanoparticles. After cycling, nano-MIs studied here suffered a lower decrease in heat of fusion than pure MI, which makes nano-MIs more suitable for solar thermal storage applications at 160–260 °C. Between CuO and Al_2O_3 nanoparticles, latter was found to be more suitable for compact solar thermal energy storage owing to an increase in melting point observed.

Solar thermal repowering systems integration. Final report

Energy Technology Data Exchange (ETDEWEB)

Dubberly, L. J.; Gormely, J. E.; McKenzie, A. W.

1979-08-01

This report is a solar repowering integration analysis which defines the balance-of-plant characteristics and costs associated with the solar thermal repowering of existing gas/oil-fired electric generating plants. Solar repowering interface requirements for water/steam and salt or sodium-cooled central receivers are defined for unit sizes ranging from 50 MWe non-reheat to 350 MWe reheat. Finally balance-of-plant cost estimates are presented for each of six combinations of plant type, receiver type and percent solar repowering.

Solar Energy: Energy Conservation and Passive Design Concepts: Student Material. First Edition.

Science.gov (United States)

Younger, Charles; Orsak, Charles G., Jr.

Designed for student use in "Energy Conservation and Passive Design Concepts," one of 11 courses in a 2-year associate degree program in solar technology, this manual provides readings, bibliographies, and illustrations for seven course modules. The manual, which corresponds to an instructor guide for the same course, covers the…

Atomic-layer deposited Nb2O5 as transparent passivating electron contact for c-Si solar cells

NARCIS (Netherlands)

Macco, Bart; Black, Lachlan E.; Melskens, Jimmy; van de Loo, Bas W.H.; Berghuis, Willem Jan H.; Verheijen, Marcel A.; Kessels, Wilhelmus M.M.

2018-01-01

Passivating contacts based on metal oxides have proven to enable high energy conversion efficiencies for crystalline silicon (c-Si) solar cells at low processing complexity. In this work, the potential of atomic-layer deposited (ALD) Nb2O5 as novel electron-selective passivating contact is explored

Energy Efficiency Enhancement of Photovoltaics by Phase Change Materials through Thermal Energy Recovery

Directory of Open Access Journals (Sweden)

Ahmad Hasan

2016-09-01

Full Text Available Photovoltaic (PV panels convert a certain amount of incident solar radiation into electricity, while the rest is converted to heat, leading to a temperature rise in the PV. This elevated temperature deteriorates the power output and induces structural degradation, resulting in reduced PV lifespan. One potential solution entails PV thermal management employing active and passive means. The traditional passive means are found to be largely ineffective, while active means are considered to be energy intensive. A passive thermal management system using phase change materials (PCMs can effectively limit PV temperature rises. The PCM-based approach however is cost inefficient unless the stored thermal energy is recovered effectively. The current article investigates a way to utilize the thermal energy stored in the PCM behind the PV for domestic water heating applications. The system is evaluated in the winter conditions of UAE to deliver heat during water heating demand periods. The proposed system achieved a ~1.3% increase in PV electrical conversion efficiency, along with the recovery of ~41% of the thermal energy compared to the incident solar radiation.

Willow Park II Community Center. Design report for the passive solar commercial buildings design assistance and demonstration program

Energy Technology Data Exchange (ETDEWEB)

None

1981-01-15

The design process for a passive solar community center in Texas is documented. Weather data are given. Energy analysis for early drawings is performed using the ENERGYLOOK program and the results shown graphically. Energy consumption and cost data are given. The design evolution is then traced and the performance of alternative designs compared. Design indicators for best strategies and concepts are discussed and the final design is presented. Energy consumption and cost are given, along with incremental passive solar design costs. A schematic review meeting report and life cycle value tables are included. Overviews, unavailable information, incremental passive design costs, performance comparison of alternatives, and architectural compatibility are discussed for each step in the design process. (LEW)

Output performance analyses of solar array on stratospheric airship with thermal effect

International Nuclear Information System (INIS)

Li, Jun; Lv, Mingyun; Tan, Dongjie; Zhu, Weiyu; Sun, Kangwen; Zhang, Yuanyuan

2016-01-01

Highlights: • A model investigating the output power of solar array is proposed. • The output power in the cruise condition with thermal effect is researched. • The effect of some factors on output performance is discussed in detail. • A suitable transmissivity of external layer is crucial in preliminary design step. - Abstract: Output performance analyses of the solar array are very critical for solving the energy problem of a long endurance stratospheric airship, and the solar cell efficiency is very sensitive to temperature of the solar cell. But the research about output performance of solar array with thermal effect is rare. This paper outlines a numerical model including the thermal model of airship and solar cells, the incident solar radiation model on the solar array, and the power output model. Based on this numerical model, a MATLAB computer program is developed. In the course of the investigation, the comparisons of the simulation results with and without considering thermal effect are reported. Furthermore, effects of the transmissivity of external encapsulation layer of solar array and wind speed on the thermal performance and output power of solar array are discussed in detail. The results indicate that this method is helpful for planning energy management.

Simulation of an active solar energy system integrated in a passive building in order to obtain system efficiency

Science.gov (United States)

Ceacaru, Mihai C.

2012-11-01

In this work we present a simulation of an active solar energy system. This system belongs to the first passive office building (2086 square meters) in Romania and it is used for water heating consumption. This office building was opened in February 2009 and was built based on passive house design solutions. For this simulation, we use Solar Water Heating module, which belongs to the software RETSCREEN and this simulation is done for several cities in Romania. Results obtained will be compared graphically.

Thermo-economic analysis of Shiraz solar thermal power plant

Energy Technology Data Exchange (ETDEWEB)

Yaghoubi, M. [Academy of Science, Tehran (Iran, Islamic Republic of); Mokhtari, A.; Hesami, R. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). School of Engineering

2007-07-01

The Shiraz solar thermal power plant in Iran has 48 parabolic trough collectors (PTCs) which are used to heat the working oil. There is potential to significantly increase the performance and reduce the cost of PTC solar thermal electric technologies. Conventional energy analysis based on the first law of thermodynamics does qualitatively assess the various losses occurring in the components. Therefore, exergy analysis, based on the second law of thermodynamics, can be applied to better assess various losses quantitatively as well as qualitatively. This paper presented a newly developed exergy-economic model for the Shiraz solar thermal power plant. The objective was to find the minimum exergetic production cost (EPC), based on the second law of thermodynamics. The application of exergy-economic analysis includes the evaluation of utility supply costs for production plants, and the energy costs for process operations. The purpose of the analysis was to minimize the total operating costs of the solar thermal power plant by assuming a fixed rate of electricity production and process steam. 21 refs., 3 tabs., 8 figs.

Al-Si alloy point contact formation and rear surface passivation for silicon solar cells using double layer porous silicon

International Nuclear Information System (INIS)

Moumni, Besma; Ben Jaballah, Abdelkader; Bessais, Brahim

2012-01-01

Lowering the rear surface recombination velocities by a dielectric layer has fascinating advantages compared with the standard fully covered Al back-contact silicon solar cells. In this work the passivation effect by double layer porous silicon (PS) (wide band gap) and the formation of Al-Si alloy in narrow p-type Si point contact areas for rear passivated solar cells are analysed. As revealed by Fourier transform infrared spectroscopy, we found that a thin passivating aluminum oxide (Al 2 O 3 ) layer is formed. Scanning electron microscopy analysis performed in cross sections shows that with bilayer PS, liquid Al penetrates into the openings, alloying with the Si substrate at depth and decreasing the contact resistivity. At the solar cell level, the reduction in the contact area and resistivity leads to a minimization of the fill factor losses.

Passive thermal management using phase change materials

Science.gov (United States)

Ganatra, Yash Yogesh

The trend of enhanced functionality and reducing thickness of mobile devices has. led to a rapid increase in power density and a potential thermal bottleneck since. thermal limits of components remain unchanged. Active cooling mechanisms are not. feasible due to size, weight and cost constraints. This work explores the feasibility. of a passive cooling system based on Phase Change Materials (PCMs) for thermal. management of mobile devices. PCMs stabilize temperatures due to the latent heat. of phase change thus increasing the operating time of the device before threshold. temperatures are exceeded. The primary contribution of this work is the identification. of key parameters which influence the design of a PCM based thermal management. system from both the experiments and the numerical models. This work first identifies strategies for integrating PCMs in an electronic device. A. detailed review of past research, including experimental techniques and computational. models, yields key material properties and metrics to evaluate the performance of. PCMs. Subsequently, a miniaturized version of a conventional thermal conductivity. measurement technique is developed to characterize thermal resistance of PCMs. Further, latent heat and transition temperatures are also characterized for a wide. range of PCMs. In-situ measurements with PCMs placed on the processor indicate that some. PCMs can extend the operating time of the device by as much as a factor of 2.48. relative to baseline tests (with no PCMs). This increase in operating time is investigated. by computational thermal models that explore various integration locations, both at the package and device level.

Anti-reflecting and passivating coatings for silicon solar cells on a basis of SO2 and TiO2 layers

International Nuclear Information System (INIS)

Taurbaev, T.I.; Nikulin, V.Eh.; Shorin, V.F.; Topanov, B.G.; Dikhanbaev, K.K.

2002-01-01

An analysis of influence of passivating layer on performance of anti-reflection coating of solar cells is carried out. The introduction of passivating SiO 2 layer between a frontal surface of the solar cell and TiO 2 +SiO 2 anti-reflection coating increase total reflection. If a thickness of a passivating layer no more than 20 Angstrom an increase of reflection does not exceed 0.5 %. However, for effective passivation the thickness of the passivating layer has to be within 100-1000 Angstrom region, thus the interference contribution of the passivating layer becomes essential and the AC is necessary to calculate as triple system SiO 2 -TiO 2 -SiO 2 . Such the three layers system ensuring average coefficient of reflection less of 3.5 % in a range 0.4-1.1 μm if the thickness of passivating SiO 2 layer no more 200 Angstrom. For solar cells with passivating SiO 2 layer thickness of 100 Angstrom and protective glass of non-interference thickness the single layer AC from TiO 2 allows to receive average value of reflection coefficient for a spectral range 0.4-1.1 μm no more than 9.5 %. The introduction of two additional layers SiO 2 and TiO 2 allows to reduce this value on 2.0-3.0 %. The comparison of calculation and experimental results is given. (author)

Solar dryer with thermal storage and biomass-backup heater

Energy Technology Data Exchange (ETDEWEB)

Madhlopa, A. [Department of Physics and Biochemical Sciences, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi); Ngwalo, G. [Department of Mechanical Engineering, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi)

2007-04-15

An indirect type natural convection solar dryer with integrated collector-storage solar and biomass-backup heaters has been designed, constructed and evaluated. The major components of the dryer are biomass burner (with a rectangular duct and flue gas chimney), collector-storage thermal mass and drying chamber (with a conventional solar chimney). The thermal mass was placed in the top part of the biomass burner enclosure. The dryer was fabricated using simple materials, tools and skills, and it was tested in three modes of operation (solar, biomass and solar-biomass) by drying twelve batches of fresh pineapple (Ananas comosus), with each batch weighing about 20 kg. Meteorological conditions were monitored during the dehydration process. Moisture and vitamin C contents were determined in both fresh and dried samples. Results show that the thermal mass was capable of storing part of the absorbed solar energy and heat from the burner. It was possible to dry a batch of pineapples using solar energy only on clear days. Drying proceeded successfully even under unfavorable weather conditions in the solar-biomass mode of operation. In this operational mode, the dryer reduced the moisture content of pineapple slices from about 669 to 11% (db) and yielded a nutritious dried product. The average values of the final-day moisture-pickup efficiency were 15%, 11% and 13% in the solar, biomass and solar-biomass modes of operation respectively. It appears that the solar dryer is suitable for preservation of pineapples and other fresh foods. Further improvements to the system design are suggested. (author)

Profits or preferences? Assessing the adoption of residential solar thermal technologies

International Nuclear Information System (INIS)

Mills, Bradford F.; Schleich, Joachim

2009-01-01

Solar thermal technologies offer the potential to meet a substantial share of residential water and space heating needs in the EU, but current levels of adoption are low. This paper uses data from a large sample of German households to assess the effects of geographic, residence, and household characteristics on the adoption of solar thermal water and space heating technologies. In addition, the impact of solar thermal technology adoption on household energy expenditures is estimated after controlling for observed household heterogeneity in geographic, residential, and household characteristics. While evidence is found of moderate household energy expenditure savings from combined solar water and space heating systems, the findings generally confirm that low in-home energy cost savings and fixed housing stocks limit the diffusion of residential solar thermal technologies. Little evidence is found of differential adoption by distinct socio-economic groups.

Climate classification and passive solar design implications in China

Energy Technology Data Exchange (ETDEWEB)

Lau, Chris C.S.; Lam, Joseph C. [Building Energy Research Group, Department of Building and Construction, City University of Hong Kong, Kowloon, Hong Kong (China); Yang, Liu [School of Architecture, Xi' an University of Architecture and Technology, Shaanxi 710055 (China)

2007-07-15

China's climate differs greatly in various regions, ranging from severe cold to hot and arid to humid. This has significant influences on energy efficient building design strategies and energy use. Solar radiation data from 123 measuring stations were used to propose a map indicating the solar radiation climates in China. A cluster analysis was adopted to identify the prevailing solar climates using the monthly average daily clearness index, K{sub t}, as climatic variable. Five major solar climates were identified with annual average K{sub t} ranging from 0.3 in the Sichuan Basin to 0.65 in the north and northwest regions. The solar climates were compared with the more widely used general (thermal) climates (severe cold, cold, hot summer and cold winter, mild and hot summer and warm winter) and the major topography (basin, plain and plateau), and implications for building designs were briefly discussed. (author)

Climate classification and passive solar design implications in China

International Nuclear Information System (INIS)

Lau, Chris C.S.; Lam, Joseph C.; Yang, Liu

2007-01-01

China's climate differs greatly in various regions, ranging from severe cold to hot and arid to humid. This has significant influences on energy efficient building design strategies and energy use. Solar radiation data from 123 measuring stations were used to propose a map indicating the solar radiation climates in China. A cluster analysis was adopted to identify the prevailing solar climates using the monthly average daily clearness index, K t , as climatic variable. Five major solar climates were identified with annual average K t ranging from 0.3 in the Sichuan Basin to 0.65 in the north and northwest regions. The solar climates were compared with the more widely used general (thermal) climates (severe cold, cold, hot summer and cold winter, mild and hot summer and warm winter) and the major topography (basin, plain and plateau), and implications for building designs were briefly discussed

Thermal energy storage for CSP (Concentrating Solar Power)

Science.gov (United States)

Py, Xavier; Sadiki, Najim; Olives, Régis; Goetz, Vincent; Falcoz, Quentin

2017-07-01

The major advantage of concentrating solar power before photovoltaic is the possibility to store thermal energy at large scale allowing dispatchability. Then, only CSP solar power plants including thermal storage can be operated 24 h/day using exclusively the solar resource. Nevertheless, due to a too low availability in mined nitrate salts, the actual mature technology of the two tanks molten salts cannot be applied to achieve the expected international share in the power production for 2050. Then alternative storage materials are under studies such as natural rocks and recycled ceramics made from industrial wastes. The present paper is a review of those alternative approaches.

Thermal energy storage for CSP (Concentrating Solar Power

Directory of Open Access Journals (Sweden)

Py Xavier

2017-01-01

Full Text Available The major advantage of concentrating solar power before photovoltaic is the possibility to store thermal energy at large scale allowing dispatchability. Then, only CSP solar power plants including thermal storage can be operated 24 h/day using exclusively the solar resource. Nevertheless, due to a too low availability in mined nitrate salts, the actual mature technology of the two tanks molten salts cannot be applied to achieve the expected international share in the power production for 2050. Then alternative storage materials are under studies such as natural rocks and recycled ceramics made from industrial wastes. The present paper is a review of those alternative approaches.

Monitoring solar-thermal systems: An outline of methods and procedures

Energy Technology Data Exchange (ETDEWEB)

Rosenthal, A. [New Mexico State Univ., Las Cruces, NM (United States). Southwest Technology Development Inst.

1994-04-01

This manual discusses the technical issues associated with monitoring solar-thermal systems. It discusses some successful monitoring programs that have been implemented in the past. It gives the rationale for selecting a program of monitoring and gives guidelines for the design of new programs. In this report, solar thermal monitoring systems are classified into three levels. For each level, the report discusses the kinds of information obtained by monitoring, the effort needed to support the monitoring program, the hardware required, and the costs involved. Ultimately, all monitoring programs share one common requirement: the collection of accurate data that characterize some aspect or aspects of the system under study. This report addresses most of the issues involved with monitoring solar thermal systems. It does not address such topics as design fundamentals of thermal systems or the relative merits of the many different technologies employed for collection of solar energy.

Mathematical model for thermal solar collectors by using magnetohydrodynamic Maxwell nanofluid with slip conditions, thermal radiation and variable thermal conductivity

Science.gov (United States)

Mahmood, Asif; Aziz, Asim; Jamshed, Wasim; Hussain, Sajid

Solar energy is the cleanest, renewable and most abundant source of energy available on earth. The main use of solar energy is to heat and cool buildings, heat water and to generate electricity. There are two types of solar energy collection system, the photovoltaic systems and the solar thermal collectors. The efficiency of any solar thermal system depend on the thermophysical properties of the operating fluids and the geometry/length of the system in which fluid is flowing. In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The flow is induced by a non-uniform stretching of the porous sheet and the uniform magnetic field is applied in the transverse direction to the flow. The non-Newtonian Maxwell fluid model is utilized for the working fluid along with slip boundary conditions. Moreover the high temperature effect of thermal radiation and temperature dependent thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for cu-water and TiO2 -water nanofluids. Results are presented for the velocity and temperature profiles as well as the skin friction coefficient and Nusselt number and the discussion is concluded on the effect of various governing parameters on the motion, temperature variation, velocity gradient and the rate of heat transfer at the boundary.

High thermal performance lithium-ion battery pack including hybrid active–passive thermal management system for using in hybrid/electric vehicles

International Nuclear Information System (INIS)

Fathabadi, Hassan

2014-01-01

In this study, a novel Li-ion battery pack design including hybrid active–passive thermal management system is presented. The battery pack is suitable for using in hybrid/electric vehicles. Active part of the hybrid thermal management system uses distributed thin ducts, air flow and natural convection as cooling media while the passive part utilizes phase change material/expanded graphite composite (PCM/EG) as cooling/heating component to optimize the thermal performance of the proposed battery pack. High melting enthalpy of PCM/EG composite together with melting of PCM/EG composite at the temperature of 58.9 °C remains the temperature distribution of the battery units in the desired temperature range (below 60 °C). The temperature and voltage distributions in the proposed battery pack design consisting of battery units, distributed thin ducts and PCM/EG composite are calculated by numerical solving of the related partial differential equations. Simulation results obtained by writing M-files code in Matlab environment and plotting the numerical data are presented to validate the theoretical results. A comparison between the thermal and physical characteristics of the proposed battery pack and other latest works is presented that explicitly proves the battery pack performance. - Highlights: • Novel Li-ion battery pack including active and passive thermal management systems. • The battery pack has high thermal performance for ambient temperatures until 55 °C. • Uniform temperature and voltage distributions. • The maximum observed temperature in each battery unit is less than other works. • The maximum temperature dispersion in each battery is less than other works

The solar thermal market in Greece - review and perspectives

International Nuclear Information System (INIS)

Argiriou, A.A.; Mirasgedis, S.

2003-01-01

The Hellenic solar thermal market is actually one of the most developed worldwide. This paper provides an overview of the evolution of this market since its start in the mid-1970s until today. The reasons for its success are discussed in detail: the role of the manufacturers, the quality assurance practices applied and the incentives on the demand and supply sides. The role of economic instruments towards the development of the Hellenic solar thermal market is investigated using a cost-benefit analysis (CBA). Although commercially successful, solar thermal applications today in Greece still cover a very limited percentage of their potential applications. The perspectives and potential barriers for their future development are presented, analysed by a CBA and discussed. This information is useful for all parties related to this market, manufacturers, potential users, policy makers, etc. Countries having a solar energy potential similar to that of Greece but a less developed solar market may also identify in this work parameters that will contribute to the development of their national market. (author)

Ambient plasma treatment of silicon wafers for surface passivation recovery

Science.gov (United States)

Ge, Jia; Prinz, Markus; Markert, Thomas; Aberle, Armin G.; Mueller, Thomas

2017-08-01

In this work, the effect of an ambient plasma treatment powered by compressed dry air on the passivation quality of silicon wafers coated with intrinsic amorphous silicon sub-oxide is investigated. While long-time storage deteriorates the effective lifetime of all samples, a short ambient plasma treatment improves their passivation qualities. By studying the influence of the plasma treatment parameters on the passivation layers, an optimized process condition was identified which even boosted the passivation quality beyond its original value obtained immediately after deposition. On the other hand, the absence of stringent requirement on gas precursors, vacuum condition and longtime processing makes the ambient plasma treatment an excellent candidate to replace conventional thermal annealing in industrial heterojunction solar cell production.

Solar heating at the P. E. I. Ark

Energy Technology Data Exchange (ETDEWEB)

MacKay, K.T.

1979-01-01

Both active and passive solar heating systems are employed at the P.E.I. Ark. An active drain-down system, which stores heat in water located in 70,000 litre concrete tanks, supplies heat to the living area. Domestic hot water is heated by a thermosiphon drain-down solar system coupled to a wood cookstove. Environmental design of the Ark allows for maximum use of passive solar energy. The passive system supplies the majority of the heating load on sunny days, while wood stoves supply the back-up heat. The performance of the active system has required high maintenance because of problems in the mechanical and electrical systems. This, coupled with the high initial cost, has not made the system cost effective. The 178m/sup 2/ commercial greenhouse uses a hybrid system with both active and passive systems. The active system employs a fan to draw air through rock storage. The passive system employs the high thermal mass of the deep soil beds, a concrete slab, and most importantly, 53,200 litres of water in translucent tanks. These tanks are then used for fish rearing and are the basis for a solar hatchery. The greenhouse has performed very well, producing crops year round since 1976.

Low temperature surface passivation of crystalline silicon and its application to interdigitated back contact silicon heterojunction (ibc-shj) solar cell

Science.gov (United States)

Shu, Zhan

With the absence of shading loss together with improved quality of surface passivation introduced by low temperature processed amorphous silicon crystalline silicon (a-Si:H/c-Si) heterojunction, the interdigitated back contact silicon heterojunction (IBC-SHJ) solar cell exhibits a potential for higher conversion efficiency and lower cost than a traditional front contact diffused junction solar cell. In such solar cells, the front surface passivation is of great importance to achieve both high open-circuit voltage (Voc) and short-circuit current (Jsc). Therefore, the motivation of this work is to develop a low temperature processed structure for the front surface passivation of IBC-SHJ solar cells, which must have an excellent and stable passivation quality as well as a good anti-reflection property. Four different thin film materials/structures were studied and evaluated for this purpose, namely: amorphous silicon nitride (a-SiNx:H), thick amorphous silicon film (a-Si:H), amorphous silicon/silicon nitride/silicon carbide (a-Si:H/a-SiN x:H/a-SiC:H) stack structure with an ultra-thin a-Si:H layer, and zinc sulfide (ZnS). It was demonstrated that the a-Si:H/a-SiNx:H/a-SiC:H stack surpasses other candidates due to both of its excellent surface passivation quality (SRVSi surface is found to be resulted from (i) field effect passivation due to the positive fixed charge (Q fix~1x1011 cm-2 with 5 nm a-Si:H layer) in a-SiNx:H as measured from capacitance-voltage technique, and (ii) reduced defect state density (mid-gap Dit~4x1010 cm-2eV-1) at a-Si:H/c-Si interface provided by a 5 nm thick a-Si:H layer, as characterized by conductance-frequency measurements. Paralleled with the experimental studies, a computer program was developed in this work based on the extended Shockley-Read-Hall (SRH) model of surface recombination. With the help of this program, the experimental injection level dependent SRV curves of the stack passivated c-Si samples were successfully reproduced and

Applicability of advanced automotive heat engines to solar thermal power

Science.gov (United States)

Beremand, D. G.; Evans, D. G.; Alger, D. L.

The requirements of a solar thermal power system are reviewed and compared with the predicted characteristics of automobile engines under development. A good match is found in terms of power level and efficiency when the automobile engines, designed for maximum powers of 65-100 kW (87 to 133 hp) are operated to the nominal 20-40 kW electric output requirement of the solar thermal application. At these reduced power levels it appears that the automotive gas turbine and Stirling engines have the potential to deliver the 40+ percent efficiency goal of the solar thermal program.

Thermal performance of a transpired solar collector updraft tower

International Nuclear Information System (INIS)

Eryener, Dogan; Hollick, John; Kuscu, Hilmi

2017-01-01

Highlights: • Transpired solar collector updraft tower has been studied experimentally. • Transpired solar collector updraft tower efficiency ranges from 60 to 80%. • A comparison has been made with other SUT prototypes. • Three times higher efficiency compared to the glazed collectors of conventional solar towers. - Abstract: A novel solar updraft tower prototype, which consists of transpired solar collector, is studied, its function principle is described and its experimental thermal performance is presented for the first time. A test unit of transpired solar collector updraft tower was installed at the campus of Trakya University Engineering Faculty in Edirne-Turkey in 2014. Solar radiation, ambient temperature, collector cavity temperatures, and chimney velocities were monitored during summer and winter period. The results showed that transpired solar collector efficiency ranges from 60% to 80%. The maximum temperature rise in the collector area is found to be 16–18 °C on the typical sunny day. Compared to conventional solar tower glazed collectors, three times higher efficiency is obtained. With increased thermal efficiency, large solar collector areas for solar towers can be reduced in half or less.

Passive and hybrid solar manufactured housing and buildings. [Includes architectural drawings

Energy Technology Data Exchange (ETDEWEB)

Scholz, D; Bowling, C; Winter, S; Levy, E; Marks, R; Zgolinski, A

1980-01-01

The final design work on a passive solar two story modular home to be built by Unibilt Industries is summarized. After reviewing alternative insulation, glazing, and water wall schemes, five options were identified for detailed energy use and life cycle cost analysis. Using the PASCALC/SLR analysis procedure, the performance of the base case home and each of the energy conservation options was calculated. (MHR)

Investigation of exergy and yield of a passive solar water desalination system with a parabolic concentrator incorporated with latent heat storage medium

International Nuclear Information System (INIS)

Kabeel, A.E.; Elkelawy, Medhat; Alm El Din, Hagar; Alghrubah, Adel

2017-01-01

Highlights: • The impact of PCM and solar concentrator on the production of solar still studied experimentally under Egyptian conditions. • Exergetic analysis studied for passive solar still in winter and summer at different water depth. • Experimental study of water depth effect on solar still with PCM and solar concentrator. • A comparison between improved still with and usual still is carried out for winter and summer. - Abstract: In the present study, two solar stills were assembled and experienced to evaluate the yield and energy performance of an improved passive solar desalination system compared to a conventional one. The improved still is incorporated with a latent heat thermal energy storage medium and a parabolic solar concentrator. A parabolic solar concentrator was added to concentrate and increase the amount of solar irradiance absorbed by the still basin. Paraffin wax was applied as phase change material (PCM) in the solar still bottom plate. In the current study also, the effect of impure water profundity inside the still on still’s accumulated yield have been assessed. The following study involved a mathematical analysis for calculation of the exergetic proficiency as an efficient tool for the optimization, and yield evaluation of any energy systems and solar stills as well. Experimental research conducted in steady days of summer and winter at six different values of impure water profundity inside the solar still basin. The salinity of the impure water tested was about 3000–5000 ppm, while the salinity for the resulted drinkable water was about 550–500 ppm. The performed outcomes revealed that during summer, exergetic efficiency is higher than its qualified value in winter with approximately (10–15%) for the same water profundity. Results also disclosed that, the exergetic efficiency is higher when the water profundity in the basin is lower with approximately (6–9%). The experimental findings reveals that, the solar still with

Solar thermal electricity generation

Science.gov (United States)

Gasemagha, Khairy Ramadan

1993-01-01

This report presents the results of modeling the thermal performance and economic feasibility of large (utility scale) and small solar thermal power plants for electricity generation. A number of solar concepts for power systems applications have been investigated. Each concept has been analyzed over a range of plant power ratings from 1 MW(sub e) to 300 MW(sub e) and over a range of capacity factors from a no-storage case (capacity factor of about 0.25 to 0.30) up to intermediate load capacity factors in the range of 0.46 to 0.60. The solar plant's economic viability is investigated by examining the effect of various parameters on the plant costs (both capital and O & M) and the levelized energy costs (LEC). The cost components are reported in six categories: collectors, energy transport, energy storage, energy conversion, balance of plant, and indirect/contingency costs. Concentrator and receiver costs are included in the collector category. Thermal and electric energy transport costs are included in the energy transport category. Costs for the thermal or electric storage are included in the energy storage category; energy conversion costs are included in the energy conversion category. The balance of plant cost category comprises the structures, land, service facilities, power conditioning, instrumentation and controls, and spare part costs. The indirect/contingency category consists of the indirect construction and the contingency costs. The concepts included in the study are (1) molten salt cavity central receiver with salt storage (PFCR/R-C-Salt); (2) molten salt external central receiver with salt storage (PFCR/R-E-Salt); (3) sodium external central receiver with sodium storage (PFCR/RE-Na); (4) sodium external central receiver with salt storage (PFCR/R-E-Na/Salt); (5) water/steam external central receiver with oil/rock storage (PFCR/R-E-W/S); (6) parabolic dish with stirling engine conversion and lead acid battery storage (PFDR/SLAB); (7) parabolic dish

Thermal performance of Danish solar combi systems in practice and in theory

DEFF Research Database (Denmark)

Andersen, Elsa; Shah, Louise Jivan; Furbo, Simon

2004-01-01

An overview of measured thermal performances of Danish solar combi systems in practice is given. The thermal performance varies greatly from system to system. Measured and calculated thermal performances of different solar combi systems are compared and the main reasons for the different thermal ...... as theoretically expected....

4. meeting on passive solar energy houses. Proceedings; 4. Passivhaus Tagung. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

Feist, W. [ed.; Sariri, V.; Nagel, M. [comps.] [Passivhaus Institut, Darmstadt (Germany)

2000-03-01

This is the report on the 4th Passive Building Conference, which took place at Kassel on March 10/11, 2000. There were eight sections: (a) Planners' workshop; (b) Architecture; (c) Ventilation; (d) Construction practice; (e) Subjective users' comfort and measured results; (f) Practical implementation; (g) economic and ecological assessment; (h) Solar architecture; (i) Heat supply. It was considered particularly favourable that passive solar buildings do not only offer a solution to ecological problems but also a growing market. [German] Der Tagungsband der '4. Passivhaus Tagung', die von 10. bis 11. Maerz 2000 in Kassel stattgefunden hat, beinhalten Beitraege, die in acht Arbeitsgruppen vorgetragen worden: (a) Planer-Werkstatt; (b) Architektur; (c) Lueftungsplanung; (d) Baupraxis; (e) Wohnerfahrung, Messergebnisse; (f) Umsetzung; (g) oekonomische und oekologische Bewertung; (h) Solararchitektur; (i) Waermeversorgung. Es wird vom Herausgeber als besonders erfreulich herausgestellt, dass durch eine erfolgreiche Passivhaus-Entwicklung neben der Loesung der Klimaprobleme zugleich ein neuer Wachstumsmarkt geschaffen werde, der mit einer Mehrung von Wertschoepfung und Wohlstand verbunden ist. (AKF)

Proceedings of the General Committee for solar thermal energy 2017

International Nuclear Information System (INIS)

Loyen, Richard; Gibert, Francois; Porcheyre, Edwige; Laplagne, Valerie; Lambertucci, Stefano; Hauser, Eva; Delmas, Pierre; Mozas, Kevin; Servier, Gerard; Girard, Jean-Paul; Haim, Philippe; Gendron, Marc; Haas, Benjamin; Leclech, Rodrigue; Eberhardt, Mathieu; Bettwy, Fabrice; Berthomieu, Nadine; Barais, Claire; Mingant, Sylvie; Daniel, Charles; GODIN, Olivier; PELe, Charles; Benabdelkarim, Mohamed; Brottier, Laetitia; Cholin, Xavier; Mugnier, Daniel; Marchal, David; Khebchache, Bouzid

2017-10-01

The contributions of this conference first proposed an overview of the status and perspectives of the solar thermal energy sector with a presentation of the present situation and perspectives for the French market, and an overview of situations and initiatives in neighbouring European countries. A second session addressed the possible new economical and marketing models able to face challenges of solar thermal energy in 2018 with focuses on heat kWh purchase, on supply portage through a global operator contract (design-realisation-exploitation-maintenance contracts or CREM contracts, energy performance contracts or CPE), and on issues related to building renovation (solar-gas synergy) and to new buildings (regulatory evolution, E+C label). The third session proposed examples of local good practices: development of solar thermal networks in Auvergne-Rhone-Alpes with the development of these networks and a support to commissioners, ADEME's support with patrimony-rehabilitation contracts, and the solar policy implemented by the Brest metropole. A technological focus was then proposed. It addressed communications about the SOCOL approach, concentration-based solar technology (technology, applications, realisations), and solar heating (assets in new and renovated buildings). Before a synthesis, two interventions addressed the production of solar electron and calories, and works performed on the increase of the solar coverage rate

Thermal-CFD Analysis of Combined Solar-Nuclear Cycle Systems.

Energy Technology Data Exchange (ETDEWEB)

Fathi, Nima [Univ. of New Mexico, Albuquerque, NM (United States); McDaniel, Patrick [Univ. of New Mexico, Albuquerque, NM (United States); Vorobieff, Peter [Univ. of New Mexico, Albuquerque, NM (United States); de Oliveira, Cassiano [Univ. of New Mexico, Albuquerque, NM (United States); Rodriguez, Salvador B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Aleyasin, Seyed Sobhan [Univ. of Manitoba (Canada)

2015-09-01

The aim of this paper is evaluating the efficiency of a novel combined solar-nuclear cycle. CFD-Thermal analysis is performed to apply the available surplus heat from the nuclear cycle and measure the available kinetic energy of air for the turbine of a solar chimney power plant system (SCPPS). The presented idea helps to decrease the thermal pollution and handle the water shortage supply for water plant by replacing the cooling tower by solar chimney power plant to get the surplus heat from the available warm air in the secondary loop of the reactor. By applying this idea to a typical 1000 MW nuclear power plant with a 0.33 thermal efficiency, we can increase it to 0.39.

Surface Passivation and Antireflection Behavior of ALD on n-Type Silicon for Solar Cells

Directory of Open Access Journals (Sweden)

Ing-Song Yu

2013-01-01

Full Text Available Atomic layer deposition, a method of excellent step coverage and conformal deposition, was used to deposit TiO2 thin films for the surface passivation and antireflection coating of silicon solar cells. TiO2 thin films deposited at different temperatures (200°C, 300°C, 400°C, and 500°C on FZ n-type silicon wafers are in the thickness of 66.4 nm ± 1.1 nm and in the form of self-limiting growth. For the properties of surface passivation, Si surface is effectively passivated by the 200°C deposition TiO2 thin film. Its effective minority carrier lifetime, measured by the photoconductance decay method, is improved 133% at the injection level of  cm−3. Depending on different deposition parameters and annealing processes, we can control the crystallinity of TiO2 and find low-temperature TiO2 phase (anatase better passivation performance than the high-temperature one (rutile, which is consistent with the results of work function measured by Kelvin probe. In addition, TiO2 thin films on polished Si wafer serve as good ARC layers with refractive index between 2.13 and 2.44 at 632.8 nm. Weighted average reflectance at AM1.5G reduces more than half after the deposition of TiO2. Finally, surface passivation and antireflection properties of TiO2 are stable after the cofire process of conventional crystalline Si solar cells.

Thermal stability studies on atomically clean and sulphur passivated InGaAs surfaces

Energy Technology Data Exchange (ETDEWEB)

Chauhan, Lalit; Hughes, Greg [School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland)

2013-03-15

High resolution synchrotron radiation core level photoemission measurements have been used to study the high temperature stability of sulphur passivated InGaAs surfaces and comparisons made with atomically clean surfaces subjected to the same annealing temperatures. Sulphur passivation of clean InGaAs surfaces prepared by the thermal removal of an arsenic capping layer was carried out using an in situ molecular sulphur treatment in ultra high vacuum. The elemental composition of the surfaces of these materials was measured at a series of annealing temperatures up to 530 C. Following a 480 C anneal In:Ga ratio was found to have dropped by 33% on sulphur passivated surface indicating a significant loss of indium, while no drop in indium signal was recorded at this temperature on the atomically InGaAs surface. No significant change in the As surface concentration was measured at this temperature. These results reflect the reduced thermal stability of the sulphur passivated InGaAs compared to the atomically clean surface which has implications for device fabrication. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Study on the use of TiO{sub 2} passivation layer to reduce recombination losses in dye sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Eskander bin Samsudin, Adel; Mohamed, Norani Muti; Nayan, Nafarizal; Ali, Riyaz Ahmad Mohamed; Shariffuddin, Sharifah Amira Amir; Omar, Salwa [Electrical and Electronics Department, 31750, Tronoh, Universiti Teknologi PETRONAS (Malaysia); Fundamental and Applied Sciences Department, 31750, Tronoh, Universiti Teknologi PETRONAS (Malaysia); Electronic Engineering Department, Electrical and Electronic Engineering Faculty, Universiti Tun Hussein Onn Malaysia (UTHM) (Malaysia)

2012-09-26

A lot of research on various aspects of dye solar cells (DSC) has been carried out in order to improve efficiency. This paper analyzes the utilization of TiO{sub 2} passivation layers of different thicknesses by improving the electron transport properties. Four different thicknesses of passivation layers namely 10, 20, 50 and 100 nm were deposited onto the working electrode using r.f sputtering. The electrodes were assembled into TiO{sub 2} based DSC with active area of 1 cm{sup 2}. The solar performance was investigated using 100 mW/cm{sup 2} of AM 1.5 simulated sunlight from solar simulator. The kinetics of the solar cells was investigated using Electrochemical Impedance Spectroscopy (EIS) measurement and the spectral response was measured using Incident Photon to Electron Conversion (IPCE) measurement system. The highest efficiency was found for DSC with 20 nm passivation layer. DSCs with the passivation layer have open circuit voltage, V{sub OC} increased by 57 mV, their current density, J{sub SC} increased by 0.774 mA cm{sup -2} compared to the one without the passivation layer. The quantum efficiency of the 20 nm passivation layer is the highest, peaking at the wavelength of 534 nm, resulting in the highest performance. All DSCs with the passivation layer recorded higher ratio of R{sub BR}/R{sub T} where R{sub T} is the diffusion resistance of the TiO{sub 2} particles in the mesoscopic layer and R{sub BR} is the recombination resistance of the electron to the electrolyte. This implies that the recombination of the electrolyte I{sup -}{sub 3}/3I{sup -} couple at the substrate/electrolyte interface has been effectively reduced resulting in an enhanced efficiency.

Graphene-enhanced thermal interface materials for heat removal from photovoltaic solar cells

Science.gov (United States)

Saadah, M.; Gamalath, D.; Hernandez, E.; Balandin, A. A.

2016-09-01

The increase in the temperature of photovoltaic (PV) solar cells affects negatively their power conversion efficiency and decreases their lifetime. The negative effects are particularly pronounced in concentrator solar cells. Therefore, it is crucial to limit the PV cell temperature by effectively removing the excess heat. Conventional thermal phase change materials (PCMs) and thermal interface materials (TIMs) do not possess the thermal conductivity values sufficient for thermal management of the next generation of PV cells. In this paper, we report the results of investigation of the increased efficiency of PV cells with the use of graphene-enhanced TIMs. Graphene reveals the highest values of the intrinsic thermal conductivity. It was also shown that the thermal conductivity of composites can be increased via utilization of graphene fillers. We prepared TIMs with up to 6% of graphene designed specifically for PV cell application. The solar cells were tested using the solar simulation module. It was found that the drop in the output voltage of the solar panel under two-sun concentrated illumination can be reduced from 19% to 6% when grapheneenhanced TIMs are used. The proposed method can recover up to 75% of the power loss in solar cells.

Solar thermal energy utilization in Brazil: a perspective; Utilizacao da energia solar termica no Brasil: uma perspectiva

Energy Technology Data Exchange (ETDEWEB)

Miller, Francisco Mateus [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2004-07-01

Although Brazil has a large insolation potential, utilization of solar thermal energy is still limited to few applications, like residential and commercial water heating and drying of grains. However, there are in other countries more intensive applications, like electricity generation, industrial heat and fresh water production. The present work describes which are the other ways of using solar thermal energy that have been developed in the world, approaches the main technical aspects that affect its utilization, the perspective of increasing it in Brazil and its possible barriers and, finally, PETROBRAS' studies in this area, positioning itself as an Energy Company. The main solar thermal technologies currently used in the world are evacuated collectors, that work efficiently at temperatures up to 130 deg C, and concentrating solar technologies, that can reach the temperature of 1200 deg C. Among the latter, solar trough is the technology that is already considered mature, and near to become economically viable. Brazil, at the moment, has two technological challenges: development of national technology to manufacture high performance solar collectors, like evacuated collectors and solar troughs, and the development of thermal equipment to operate at temperatures under 120 deg C, like adsorption and absorption chillers and desalination towers, that can be economically competitive. (author)

Solar thermal barometer

International Nuclear Information System (INIS)

Anon.

2009-01-01

The european solar thermal system market grew spectacularly in 2008 with over 4,6 million m 2 installed as against less than 3,1 million in 2007. This was largely due to the doubling of the German market, bu strong growth in Southern Europe also played a vital part. While 2009 is looking uncertain, the medium and long term growth prospects are still very exciting. This barometer provides statistical data on the production, market, capacity and enterprises. (A.L.B.)

Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

Science.gov (United States)

Baharin, Nuraida'Aadilia; Arzami, Amir Afiq; Singh, Baljit; Remeli, Muhammad Fairuz; Tan, Lippong; Oberoi, Amandeep

2017-04-01

In this study, a thermoelectric generator heat exchanger system was designed and simulated for electricity generation from solar pond. A thermoelectric generator heat exchanger was studied by using Computational Fluid Dynamics to simulate flow and heat transfer. A thermoelectric generator heat exchanger designed for passive in-pond flow used in solar pond for electrical power generation. A simple analysis simulation was developed to obtain the amount of electricity generated at different conditions for hot temperatures of a solar pond at different flow rates. Results indicated that the system is capable of producing electricity. This study and design provides an alternative way to generate electricity from solar pond in tropical countries like Malaysia for possible renewable energy applications.

Housing and sustainable development: perspectives offered by thermal solar energy. Particle emissions: prospective investigation of primary particle emissions in France by 2030

International Nuclear Information System (INIS)

Brignon, J.M.; Cauret, L.; Sambat, S.

2004-09-01

This publication proposes two investigation reports. A first study proposes a prospective analysis of the housing 'stock' in France and the evolution of global energy consumptions and CO 2 emissions by the housing sector, a prospective study of space heating and hot water needs by defining reference scenarios as well as a target scenario for heating consumption (based on the factor 4 of reduction of emissions by 2050), and an assessment of the contribution of the thermal solar energy applied to winter comfort under the form of direct solar floors and passive solar contributions, and applied to hot water by 2050. The contribution of the thermal solar energy is studied within its regulatory context. An analysis of urban forms is also performed to assess the potential of integration of renewable energy solutions in the existing housing stock, and thus to assess the morphological limits of an attempt of generalized solarization of roofs. The second study proposes a detailed identification and assessment of the various sources of primary particles (combustion, industrial processes, mineral extraction and processing, road transport, waste processing and elimination, agriculture, natural sources, forest fires), providing more precise results and methodological complements for some sources. It also proposes a prospective assessment of emissions and identifies the main factors of particle concentrations in urban environment

Improvement of energy performances of existing buildings by application of solar thermal systems

Directory of Open Access Journals (Sweden)

Krstić-Furundžić Aleksandra

2009-01-01

Full Text Available Improvement of energy performances of the existing buildings in the suburban settlement Konjarnik in Belgrade, by the application of solar thermal systems is the topic presented in this paper. Hypothetical models of building improvements are created to allow the benefits of applying solar thermal collectors to residential buildings in Belgrade climate conditions to be estimated. This case study presents different design variants of solar thermal collectors integrated into a multifamily building envelope. The following aspects of solar thermal systems integration are analyzed in the paper: energy, architectural, ecological and economic. The results show that in Belgrade climatic conditions significant energy savings and reduction of CO2 emissions can be obtained with the application of solar thermal collectors.

Cost-effective and reliable design of a solar thermal power plant

International Nuclear Information System (INIS)

Aliabadi, A.A.; Wallace, J.S.

2009-01-01

A design study was conducted to evaluate the cost-effectiveness of solar thermal power generation in a 50 kWe power plant that could be used in a remote location. The system combines a solar collector-thermal storage system utilizing a heat transfer fluid and a simple Rankine cycle power generator utilizing R123 refrigerant. Evacuated tube solar collectors heat mineral oil and supply it to a thermal storage tank. A mineral oil to refrigerant heat exchanger generates superheated refrigerant vapor, which drives a radial turbogenerator. Supplemental natural gas firing maintains a constant thermal storage temperature irregardless of solar conditions enabling the system to produce a constant 50 kWe output. A simulation was carried out to predict the performance of the system in the hottest summer day and the coldest winter day for southern California solar conditions. A rigorous economic analysis was conducted. The system offers advantages over advanced solar thermal power plants by implementing simple fixed evacuated tube collectors, which are less prone to damage in harsh desert environment. Also, backed up by fossil fuel power generation, it is possible to obtain continued operation even during low insolation sky conditions and at night, a feature that stand-alone PV systems do not offer. (author)

Low cost thermal solar collector

International Nuclear Information System (INIS)

Abugderah, M. M.; Schneider, E. L.; Tontini, M. V.

2006-01-01

Solar energy is a good alternative in the economy of the electric energy mainly for the water heating. However, the solar heaters used demand a high initial investment, becoming the warm water from solar energy inaccessible to a large part of the society. Thus, a low cost solar heater was developed, constructed and tested in the chemical engineering department of West Parana State University-Unioeste. This equipment consists of 300 cans, divided in 30 columns of 10 cans each, all painted in black to enhance the obsorption of the solar radiation. The columns are connected to a pipe of pvc of 8 liters with 0.085m of external diameter. The equipment is capable to heat 120 liters of water in temperatures around 60 degree centigrade. The heater is insolated in its inferior part with cardboard and aluminum, covered with a transparent plastic in its superior. The system still counts with a insulated thermal reservoir, which can conserve the water in temperatures adjusted for the night non-solar days domestic use. The advantage of the constructed is it low cost material. The results are given an graphical tabular from showing acceptable efficiencies.(Autho

Solar thermal electric power generation - an attractive option for Pakistan

International Nuclear Information System (INIS)

Khan, N.A

1999-01-01

Solar Thermal Energy is being successfully used for production of electricity in few developed countries for more than 10 years. In solar Electric Generating Systems high temperature is generated by concentrating solar energy on black absorber pipe in evacuated glass tubes. This heat is absorbed and transported with the help of high temperature oil in to highly insulated heat exchanger storage tanks. They are subsequently used to produce steam that generates power through steam turbines as in standard thermal power plants. Various components involved in Solar thermal field have been developed at the Solar Systems Laboratory of College of EME, NUST Rawalpindi. It is considered as a cost effective alternate for power generation. The research has been partially sponsored by Ministry of Science and Technology under its Public Sector Development Program (PSDP) in (1996-1998). Parabolic mirror design, fabrication, polishing, installation, solar tracking, absorber pipe, glass tubes, steam generation al have been developed. This paper will cover the details of indigenous technological break through made in this direction. (author)

Layered insulator hexagonal boron nitride for surface passivation in quantum dot solar cell

International Nuclear Information System (INIS)

Shanmugam, Mariyappan; Jain, Nikhil; Jacobs-Gedrim, Robin; Yu, Bin; Xu, Yang

2013-01-01

Single crystalline, two dimensional (2D) layered insulator hexagonal boron nitride (h-BN), is demonstrated as an emerging material candidate for surface passivation on mesoporous TiO 2 . Cadmium selenide (CdSe) quantum dot based bulk heterojunction (BHJ) solar cell employed h-BN passivated TiO 2 as an electron acceptor exhibits photoconversion efficiency ∼46% more than BHJ employed unpassivated TiO 2 . Dominant interfacial recombination pathways such as electron capture by TiO 2 surface states and recombination with hole at valence band of CdSe are efficiently controlled by h-BN enabled surface passivation, leading to improved photovoltaic performance. Highly crystalline, confirmed by transmission electron microscopy, dangling bond-free 2D layered h-BN with self-terminated atomic planes, achieved by chemical exfoliation, enables efficient passivation on TiO 2 , allowing electronic transport at TiO 2 /h-BN/CdSe interface with much lower recombination rate compared to an unpassivated TiO 2 /CdSe interface

Solar thermal energy receiver

Science.gov (United States)

Baker, Karl W. (Inventor); Dustin, Miles O. (Inventor)

1992-01-01

A plurality of heat pipes in a shell receive concentrated solar energy and transfer the energy to a heat activated system. To provide for even distribution of the energy despite uneven impingement of solar energy on the heat pipes, absence of solar energy at times, or failure of one or more of the heat pipes, energy storage means are disposed on the heat pipes which extend through a heat pipe thermal coupling means into the heat activated device. To enhance energy transfer to the heat activated device, the heat pipe coupling cavity means may be provided with extensions into the device. For use with a Stirling engine having passages for working gas, heat transfer members may be positioned to contact the gas and the heat pipes. The shell may be divided into sections by transverse walls. To prevent cavity working fluid from collecting in the extensions, a porous body is positioned in the cavity.

Solar Thermal Energy Storage in a Photochromic Macrocycle.

Science.gov (United States)

Vlasceanu, Alexandru; Broman, Søren L; Hansen, Anne S; Skov, Anders B; Cacciarini, Martina; Kadziola, Anders; Kjaergaard, Henrik G; Mikkelsen, Kurt V; Nielsen, Mogens Brøndsted

2016-07-25

The conversion and efficient storage of solar energy is recognized to hold significant potential with regard to future energy solutions. Molecular solar thermal batteries based on photochromic systems exemplify one possible technology able to harness and apply this potential. Herein is described the synthesis of a macrocycle based on a dimer of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermal couple. By taking advantage of conformational strain, this DHA-DHA macrocycle presents an improved ability to absorb and store incident light energy in chemical bonds (VHF-VHF). A stepwise energy release over two sequential ring-closing reactions (VHF→DHA) combines the advantages of an initially fast discharge, hypothetically addressing immediate energy consumption needs, followed by a slow process for consistent, long-term use. This exemplifies another step forward in the molecular engineering and design of functional organic materials towards solar thermal energy storage and release. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Laser-beam-induced current mapping evaluation of porous silicon-based passivation in polycrystalline silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Rabha, M. Ben; Bessais, B. [Laboratoire de Nanomateriaux et des Systemes pour l' Energie, Centre de Recherches et des Technologies de l' Energie - Technopole de Borj-Cedria BP 95, 2050 Hammam-Lif (Tunisia); Dimassi, W.; Bouaicha, M.; Ezzaouia, H. [Laboratoire de photovoltaique, des semiconducteurs et des nanostructures, Centre de Recherches et des Technologies de l' Energie - Technopole de Borj-Cedria BP 95, 2050 Hammam-Lif (Tunisia)

2009-05-15

In the present work, we report on the effect of introducing a superficial porous silicon (PS) layer on the performance of polycrystalline silicon (pc-Si) solar cells. Laser-beam-induced current (LBIC) mapping shows that the PS treatment on the emitter of pc-Si solar cells improves their quantum response and reduce the grain boundaries (GBs) activity. After the porous silicon treatment, mapping investigation shows an enhancement of the LBIC and the internal quantum efficiency (IQE), due to an improvement of the minority carrier diffusion length and the passivation of recombination centers at the GBs as compared to the reference substrate. It was quantitatively shown that porous silicon treatment can passivate both the grains and GBs. (author)

Improved performance in GaInNAs solar cells by hydrogen passivation

International Nuclear Information System (INIS)

Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R.; Hossain, K.; Golding, T. D.; Leroux, M.; Al Khalfioui, M.

2015-01-01

The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells

Study on thermal-hydraulic phenomena identification of passive heat removal facilities

International Nuclear Information System (INIS)

Park, J. Y.

2011-01-01

Recently, passive heat removal facilities have been integral features of new generation or future reactor designs worldwide. This is because the passive heat removal facilities depending on a natural force such as buoyancy can give much higher operational reliability compared to active heat removal facilities depending on pumped fluid flow and as a result they can decrease core damage frequency of a nuclear power plant drastically ever achievable before. Keeping pace with this global trend, SMART and APR+ reactors also have introduced passive heat removal features such as a passive residual heat removal system (PRHRS) and a passive auxiliary feed water system (PAFS) in their designs. Since many thermal-hydraulic (T-H) phenomena including steam condensation are involved during operation of the passive heat removal facilities, they ought to be properly simulated by T-H codes such as MARS-KS and RELAP5 in order to guarantee reliable safety analysis by these codes. Unfortunately, however, these T-H codes are not well validated with respect to phenomena related to passive heat removal mechanism because previous focus on these codes validation was mainly on the LB LOCA and resulting phenomena. To resolve this gap, Korea Institute of Nuclear Safety has initiated a research program on the development of safety analysis technology for passive heat removal facilities. The main target of this program is PRHRS and PAFS in SMART and APR+ reactors and through this program, validation of capability of existing T-H codes and improvement of codes regarding passive facilities analysis are to be sought. In part of this research, T-H phenomena important to passive heat removal facilities (PRHRS and PAFS) are investigated in the present study

Experimental Study on Solar Cooling Tube Using Thermal/Vacuum Emptying Method

Directory of Open Access Journals (Sweden)

Huizhong Zhao

2012-01-01

Full Text Available A solar cooling tube using thermal/vacuum emptying method was experimentally studied in this paper. The coefficient of performance (COP of the solar cooling tube was mostly affected by the vacuum degree of the system. In past research, the thermal vacuum method, using an electric oven and iodine-tungsten lamp to heat up the adsorbent bed and H2O vapor to expel the air from the solar cooling tube, was used to manufacture solar cooling tubes. This paper presents a novel thermal vacuum combined with vacuum pump method allowing an increased vacuum state for producing solar cooling tubes. The following conclusions are reached: the adsorbent bed temperature of solar cooling tube could reaches up to 233°C, and this temperature is sufficient to meet desorption demand; the refrigerator power of a single solar cooling tube varies from 1 W to 12 W; the total supply refrigerating capacity is about 287 kJ; and the COP of this solar cooling tube is about 0.215.

Solar thermal and concentrated solar power barometer - EurObserv'ER - May 2013

International Nuclear Information System (INIS)

2013-05-01

The European concentrated solar power plant market is steeling itself for tough time ahead. The number of projects under construction is a pittance compared with 2012 that was an excellent year for installations (an additional 802.5 MW of capacity recorded). This drop is the result of the moratorium on renewable energy power plants introduced by the Spanish government. The European solar thermal market is hardly any more encouraging. EurObserv'ER holds that it slipped for the fourth year in a row (it dropped 5.5% between 2011 and 2012). The newly-installed solar thermal collector surface area in the EU now stands at 3.4 million m 2 , far short of its 2008 installation record of 4.6 million m 2

THERMAL PERFORMANCE OF FLAT PLATE SOLAR COLLECTOR

Directory of Open Access Journals (Sweden)

TABET I.

2017-06-01

Full Text Available In this paper, a theoretical and experimental studyof flat platesolar water collector with reflectors.A mathematical model based on energy balance equations saw the thermal behavior of the collector is investigated. The experimental test was made at the unit research applies in renewable energy (URAER located in southern Algeria.An increase of 23% for solar radiation incident on the collector surface with the addition of the planers reflectors in the day of May, this increase causes an improvement of the performance of the collector,the fluid temperature increases with an average of 5%. Thetests conducted on the flat plate solar water collector in open circuit enabled the determination of thermal performance of the collector by estimating the daily output The thermal efficiency of the collector ranges from 1% -63% during the day, a mean value of 36%obtained.

Estec2003: European solar thermal energy conference. Proceedings; Estec2003: Europaeische Solarthermie-Konferenz. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

In December 2002 more than 40 solar thermal companies and associations joined forces in the European Solar Thermal Industry Federation (ESTIF), to strengthen support for this clean technology on the European level. ESTIF aims at building a close partnership between industry and public authorities in order to overcome the main barriers to growth. Over the last 6 months we have seen some positive developments, which we could build upon. Here are some examples: 1. Germany, the country with the largest demand for solar thermal technology, is back on track to repeat the growth rates we have witnessed in the 1990s. 2. The rules for the solar Keymark quality label were approved by CEN board in January 2003. 3. The city of Madrid became the first European capital to follow the example of Barcelona in requiring the use of solar thermal in new residential buildings. 4. The long awaited ''Sun in Action II - a solar thermal strategy for Europe was published last month. 5. Now, the first European Solar Thermal Energy Conference brings together decision makers from industry and politics to discuss the future of renewable heating and cooling in Europe. - Solar thermal has a great potential - 1.4 billion square meters in the 15 EU member states alone. 99% of this potential are still to be developed. ESTIF has made it its mission 'to achieve high priority and acceptance for solar thermal as a key element for sustainable heating and cooling in Europe and to work for the implementation, as soon as possible, of all steps necessary to realise the high potential of solar thermal'. With estec2003 we offer a platform to exchange information and opinions concerning how this goal can be achieved. The developments in different countries show that the use of solar thermal technologies does not depend on climatic conditions alone. (orig.)

High temperature solar thermal technology: The North Africa Market

Energy Technology Data Exchange (ETDEWEB)

1990-12-01

High temperature solar thermal (HTST) technology offers an attractive option for both industrialized and non-industrialized countries to generate electricity and industrial process steam. The purpose of this report is to assess the potential market for solar thermal applications in the North African countries of Algeria, Egypt, Morocco and Tunisia. North Africa was selected because of its outstanding solar resource base and the variety of applications to be found there. Diminishing oil and gas resources, coupled with expanding energy needs, opens a large potential market for the US industry. The US high temperature solar trough industry has little competition globally and could build a large market in these areas. The US is already familiar with certain solar markets in North Africa due to the supplying of substantial quantities of US-manufactured flat plate collectors to this region.

Thermal solar energy. Collective domestic hot water installations

International Nuclear Information System (INIS)

Garnier, Cedric; Chauvet, Chrystele; Fourrier, Pascal

2016-01-01

This brochure, edited by ADEME, the French office for energy management and sustainable development, gives a basic outlook on the way to complete the installation of a collective domestic water solar heating system. After some recall of what is solar energy, the thermal solar technology and the energy savings it may induce, this document presents the main hydraulic configurations of a solar heating system with water storage, the dimensioning of a solar water heating system and its cost estimation, the installation and the commissioning of the system, the monitoring and maintenance operations

Ultrafast Thermal Cycling of Solar Panels

National Research Council Canada - National Science Library

Wall, T

1998-01-01

Two new cyclers that utilize a novel hybrid approach to perform fast thermal cycling of solar panels have been built and are now operational in the Mechanics and Materials Technology Center at The Aerospace Corporation...

Here comes the sun. Solar energy technology in the USA

International Nuclear Information System (INIS)

Van der Wees, G.

1998-01-01

An overview is given of the energy policy in the USA with respect to solar energy technology and the marketing of solar energy applications. In particular, attention is paid to the Million Solar Roofs programme, small-scale and medium-scale photovoltaic (PV) systems (Residential PV and Utility Scale PV), solar thermal systems (Parabolic Trough, Power tower, and Solar Dish/Engine). Also examples of passive solar systems are given. Finally, a number of aspects with regard to market implementation, e.g. net-metering. 9 refs

Application of nanomaterials in solar thermal energy storage

Science.gov (United States)

Shamshirgaran, Seyed Reza; Khalaji Assadi, Morteza; Viswanatha Sharma, Korada

2018-06-01

Solar thermal conversion technology harvests the sun's energy, rather than fossil fuels, to generate low-cost, low/zero-emission energy in the form of heating, cooling or electrical form for residential, commercial, and industrial sectors. The advent of nanofluids and nanocomposites or phase change materials, is a new field of study which is adapted to enhance the efficiency of solar collectors. The concepts of thermal energy storage technologies are investigated and the role of nanomaterials in energy conversion is discussed. This review revealed that although the exploitation of nanomaterials will boost the performance of solar collectors almost in all cases, this would be accompanied by certain challenges such as production cost, instability, agglomeration and erosion. Earlier studies have dealt with the enhancement of thermal conductivity and heat capacity; however, less attention has been given to the facing challenges. Moreover, no exact criteria can be found for the selection of appropriate nanomaterials and their properties for a specific application. In most research studies, the nanoparticles' material and properties have not been selected based on estimated values so that all the aspects of desired application could be considered simultaneously. The wide spread use of nanomaterials can lead to cost effective solutions as well. Therefore, it seems there should be a sense of techno-economic optimization in exploiting nanomaterials for solar thermal energy storage applications. The optimization should cover the key parameters, particularly nanoparticle type, size, loading and shape which depends on the sort of application and also dispersion technology.

Application of nanomaterials in solar thermal energy storage

Science.gov (United States)

Shamshirgaran, Seyed Reza; Khalaji Assadi, Morteza; Viswanatha Sharma, Korada

2017-12-01

Solar thermal conversion technology harvests the sun's energy, rather than fossil fuels, to generate low-cost, low/zero-emission energy in the form of heating, cooling or electrical form for residential, commercial, and industrial sectors. The advent of nanofluids and nanocomposites or phase change materials, is a new field of study which is adapted to enhance the efficiency of solar collectors. The concepts of thermal energy storage technologies are investigated and the role of nanomaterials in energy conversion is discussed. This review revealed that although the exploitation of nanomaterials will boost the performance of solar collectors almost in all cases, this would be accompanied by certain challenges such as production cost, instability, agglomeration and erosion. Earlier studies have dealt with the enhancement of thermal conductivity and heat capacity; however, less attention has been given to the facing challenges. Moreover, no exact criteria can be found for the selection of appropriate nanomaterials and their properties for a specific application. In most research studies, the nanoparticles' material and properties have not been selected based on estimated values so that all the aspects of desired application could be considered simultaneously. The wide spread use of nanomaterials can lead to cost effective solutions as well. Therefore, it seems there should be a sense of techno-economic optimization in exploiting nanomaterials for solar thermal energy storage applications. The optimization should cover the key parameters, particularly nanoparticle type, size, loading and shape which depends on the sort of application and also dispersion technology.

Efficient and stable solution-processed planar perovskite solar cells via contact passivation

KAUST Repository

Tan, Hairen; Jain, Ankit; Voznyy, Oleksandr; Lan, Xinzheng; Garcí a de Arquer, F. Pelayo; Fan, James Z.; Quintero-Bermudez, Rafael; Yuan, Mingjian; Zhang, Bo; Zhao, Yicheng; Fan, Fengjia; Li, Peicheng; Quan, Li Na; Zhao, Yongbiao; Lu, Zheng-Hong; Yang, Zhenyu; Hoogland, Sjoerd; Sargent, Edward H.

2017-01-01

Planar perovskite solar cells (PSCs) made entirely via solution processing at low temperatures (<150°C) offer promise for simple manufacturing, compatibility with flexible substrates, and perovskite-based tandem devices. However, these PSCs require an electron-selective layer that performs well with similar processing. We report a contact-passivation strategy using chlorine-capped TiO2 colloidal nanocrystal film that mitigates interfacial recombination and improves interface binding in low-temperature planar solar cells. We fabricated solar cells with certified efficiencies of 20.1 and 19.5% for active areas of 0.049 and 1.1 square centimeters, respectively, achieved via low-temperature solution processing. Solar cells with efficiency greater than 20% retained 90% (97% after dark recovery) of their initial performance after 500 hours of continuous room-temperature operation at their maximum power point under 1-sun illumination (where 1 sun is defined as the standard illumination at AM1.5, or 1 kilowatt/square meter).

Efficient and stable solution-processed planar perovskite solar cells via contact passivation

KAUST Repository

Tan, Hairen

2017-02-03

Planar perovskite solar cells (PSCs) made entirely via solution processing at low temperatures (<150°C) offer promise for simple manufacturing, compatibility with flexible substrates, and perovskite-based tandem devices. However, these PSCs require an electron-selective layer that performs well with similar processing. We report a contact-passivation strategy using chlorine-capped TiO2 colloidal nanocrystal film that mitigates interfacial recombination and improves interface binding in low-temperature planar solar cells. We fabricated solar cells with certified efficiencies of 20.1 and 19.5% for active areas of 0.049 and 1.1 square centimeters, respectively, achieved via low-temperature solution processing. Solar cells with efficiency greater than 20% retained 90% (97% after dark recovery) of their initial performance after 500 hours of continuous room-temperature operation at their maximum power point under 1-sun illumination (where 1 sun is defined as the standard illumination at AM1.5, or 1 kilowatt/square meter).

Impacts of Thermal Atomic Layer-Deposited AlN Passivation Layer on GaN-on-Si High Electron Mobility Transistors.

Science.gov (United States)

Zhao, Sheng-Xun; Liu, Xiao-Yong; Zhang, Lin-Qing; Huang, Hong-Fan; Shi, Jin-Shan; Wang, Peng-Fei

2016-12-01

Thermal atomic layer deposition (ALD)-grown AlN passivation layer is applied on AlGaN/GaN-on-Si HEMT, and the impacts on drive current and leakage current are investigated. The thermal ALD-grown 30-nm amorphous AlN results in a suppressed off-state leakage; however, its drive current is unchanged. It was also observed by nano-beam diffraction method that thermal ALD-amorphous AlN layer barely enhanced the polarization. On the other hand, the plasma-enhanced chemical vapor deposition (PECVD)-deposited SiN layer enhanced the polarization and resulted in an improved drive current. The capacitance-voltage (C-V) measurement also indicates that thermal ALD passivation results in a better interface quality compared with the SiN passivation.

Solar energy in practice

International Nuclear Information System (INIS)

Eijpe, H.A.

1996-01-01

One of the Dutch energy distribution companies (REMU) applies integrated passive, thermal and photovoltaic solar energy systems in fifty newly built dwellings in Amersfoort, Netherlands. The houses are equipped with a combi-boiler (solar energy and natural gas) and 22.5m 2 photovoltaic panels to produce electricity. Six houses are equipped with an electric heat pump, while the other 44 houses have a high-efficiency low-NO x combi-boiler. The experiences with the project so-far are outlined. 6 figs., 1 tab., 10 refs

Yearly thermal performances of solar heating plants in Denmark – Measured and calculated

DEFF Research Database (Denmark)

Furbo, Simon; Dragsted, Janne; Perers, Bengt

2018-01-01

The thermal performance of solar collector fields depends mainly on the mean solar collector fluid temperature of the collector field and on the solar radiation. For Danish solar collector fields for district heating the measured yearly thermal performances per collector area varied in the period...... 2012–2016 between 313 kWh/m2 and 577 kWh/m2, with averages between 411 kWh/m2 and 463 kWh/m2. The percentage difference between the highest and lowest measured yearly thermal performance is about 84%. Calculated yearly thermal performances of typically designed large solar collector fields at six...... different locations in Denmark with measured weather data for the years 2002–2010 vary between 405 kWh/m2 collector and 566 kWh/m2 collector, if a mean solar collector fluid temperature of 60 °C is assumed. This corresponds to a percentage difference between the highest and lowest calculated yearly thermal...

High Performance Flat Plate Solar Thermal Collector Evaluation

Energy Technology Data Exchange (ETDEWEB)

Rockenbaugh, Caleb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lovullo, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lisell, Lars [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barker, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hanckock, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States); Norton, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-09-01

This report was prepared for the General Services Administration by the National Renewable Energy Laboratory. The Honeycomb Solar Thermal Collector (HSTC) is a flat plate solar thermal collector that shows promising high efficiencies over a wide range of climate zones. The technical objectives of this study are to: 1) verify collector performance, 2) compare that performance to other market-available collectors, 3) verify overheat protection, and 4) analyze the economic performance of the HSTC both at the demonstration sites and across a matrix of climate zones and utility markets.

Solar thermal collectors at design and technology activity days

OpenAIRE

Petrina, Darinka

2016-01-01

Thesis encompases usage of renewable resources of energy, especially solar energy, which is essential for our future. On one hand, certain ways of exploiting solar energy (with solar cells) have been well established and is included in the Design and technology curriculum, on the other hand however, solar thermal collectors have not been recognized enough in spite of their distribution, applicability and environmentally friendly technology. Consequently thesis emphasizes the usage of solar en...

Thermal photovoltaic solar integrated system analysis using neural networks

Energy Technology Data Exchange (ETDEWEB)

Ashhab, S. [Hashemite Univ., Zarqa (Jordan). Dept. of Mechanical Engineering

2007-07-01

The energy demand in Jordan is primarily met by petroleum products. As such, the development of renewable energy systems is quite attractive. In particular, solar energy is a promising renewable energy source in Jordan and has been used for food canning, paper production, air-conditioning and sterilization. Artificial neural networks (ANNs) have received significant attention due to their capabilities in forecasting, modelling of complex nonlinear systems and control. ANNs have been used for forecasting solar energy. This paper presented a study that examined a thermal photovoltaic solar integrated system that was built in Jordan. Historical input-output system data that was collected experimentally was used to train an ANN that predicted the collector, PV module, pump and total efficiencies. The model predicted the efficiencies well and can therefore be utilized to find the operating conditions of the system that will produce the maximum system efficiencies. The paper provided a description of the photovoltaic solar system including equations for PV module efficiency; pump efficiency; and total efficiency. The paper also presented data relevant to the system performance and neural networks. The results of a neural net model were also presented based on the thermal PV solar integrated system data that was collected. It was concluded that the neural net model of the thermal photovoltaic solar integrated system set the background for achieving the best system performance. 10 refs., 6 figs.

Solar energy guide

International Nuclear Information System (INIS)

Lentz, A.; Winter, R.

1993-07-01

Many aspects with regard to the practical use of solar energy are discussed. This guide is aimed at informing local and regional administrators, committee members of housing corporations and public utilities and public relations officers on the possibilities to use solar energy. In chapter one an overview is given of the use of solar energy in the housing sector, the recreational sector, agricultural sector, industry, trade and other sectors. In the chapters two, three and four attention is paid to passive solar energy, active thermal solar energy and photovoltaic energy respectively. In the chapters five and six aspects concerning the implementation of solar energy systems in practice are discussed. First an outline of the parties involved in implementing solar energy is given: the municipality, the energy utility, the province, local authorities, advisors, housing constructors and the occupants of the buildings. Then attention is paid to the consequences of implementing solar energy for the building inspection and regulations, the finances, energy savings and the environment. In chapter seven an overview is given of the subsidy regulations of the European Community, the Dutch national and local governments. Chapter contains addresses of solar thermal systems, photovoltaic systems and other institutes operating in the field of solar energy, as well as the titles of a number of brochures and courses. 51 figs., 7 tabs., 86 refs