Experimental validation of a heat transfer model for concentrating photovoltaic system

International Nuclear Information System (INIS)

Sendhil Kumar, Natarajan; Matty, Katz; Rita, Ebner; Simon, Weingaertner; Ortrun, Aßländer; Alex, Cole; Roland, Wertz; Tim, Giesen; Tapas Kumar, Mallick

2012-01-01

In this paper, a three dimensional heat transfer model is presented for a novel concentrating photovoltaic design for Active Solar Panel Initiative System (ASPIS). The concentration ratio of two systems (early and integrated prototype) are 5× and 10× respectively, designed for roof-top integrated Photovoltaic systems. ANSYS 12.1, CFX package was effectively used to predict the temperatures of the components of the both ASPIS systems at various boundary conditions. The predicted component temperatures of an early prototype were compared with experimental results of ASPIS, which were carried out in Solecta – Israel and at the Austrian Institute of Technology (AIT) – Austria. It was observed that the solar cell and lens temperature prediction shows good agreement with Solecta measurements. The minimum and maximum deviation of 3.8% and 17.9% were observed between numerical and Solecta measurements and the maximum deviations of 16.9% were observed between modeling and AIT measurements. Thus, the developed validated thermal model enables to predict the component temperatures for concentrating photovoltaic systems. - Highlights: ► Experimentally validated heat transfer model for concentrating Photovoltaic system developed. ► Predictions of solar cell temperatures for parallactic tracking CPV system for roof integration. ► The ASPIS module contains 2 mm wide 216 solar cells manufactured based on SATURN technology. ► A solar cell temperature of 44 °C was predicted for solar radiation intensity was 1000 W/m 2 and ambient temperature was 20 °C. ► Average deviation was 6% and enabled to predict temperature of any CPV system.

Efficiency gains of photovoltaic system using latent heat thermal energy storage

NARCIS (Netherlands)

Tan, Lippong; Date, Abhijit; Fernandes, Gabriel; Singh, Baljit; Ganguly, Sayantan

This paper presents experimental assessments of the thermal and electrical performance of photovoltaic (PV) system by comparing the latent heat-cooled PV panel with the naturally-cooled equivalent. It is commonly known that the energy conversion efficiency of the PV cells declines with the increment

Small-molecule azomethines : Organic photovoltaics via Schiff base condensation chemistry

NARCIS (Netherlands)

Petrus, M.L.; Bouwer, R.K.M.; Lafont, U.; Athanasopoulos, S.; Greenham, N.C.; Dingemans, T.J.

2014-01-01

Conjugated small-molecule azomethines for photovoltaic applications were prepared via Schiff base condensation chemistry. Bulk heterojunction (BHJ) devices exhibit efficiencies of 1.2% with MoOx as the hole-transporting layer. The versatility and simplicity of the chemistry is illustrated by

A novel solar-assisted heat pump driven by photovoltaic/thermal collectors: Dynamic simulation and thermoeconomic optimization

International Nuclear Information System (INIS)

Calise, Francesco; Dentice d'Accadia, Massimo; Figaj, Rafal Damian; Vanoli, Laura

2016-01-01

This paper presents a dynamic simulation model and a thermo-economic analysis of a novel polygeneration system based on a solar-assisted heat pump and an adsorption chiller, both driven by PVT (photovoltaic/thermal) collectors. The aim of this work is to design and dynamically simulate a novel ultra-high efficient solar heating and cooling system. The overall plant layout is designed to supply electricity, space heating and cooling and domestic hot water for a small residential building. The system combines solar cooling, solar-assisted heat pump and photovoltaic/thermal collector technologies in a novel solar polygeneration system. In fact, the polygeneration system is based on a PVT solar field, coupled with a water-to-water electric heat pump or to an adsorption chiller. PVT collectors simultaneously produce electricity and thermal energy. During the winter, hot water produced by PVT collectors primarily supplies the evaporator of the heat pump, whereas in summer, solar energy supplies an adsorption chiller providing the required space cooling. All year long, solar thermal energy in excess is converted into DHW (domestic hot water). The system model was developed in TRNSYS environment. 1-year dynamic simulations are performed for different case studies in various weather conditions. The results are analysed on different time bases presenting energetic, environmental and economic performance data. Finally, a sensitivity analysis and a thermoeconomic optimization were performed, in order to determine the set of system design/control parameters that minimize the simple pay-back period. The results showed a total energy efficiency of the PVT of 49%, a heat pump yearly coefficient of performance for heating mode above 4 and a coefficient of performance of the adsorption chiller of 0.55. Finally, it is also concluded that system performance is highly sensitive to the PVT field area. The system is profitable when a capital investment subsidy of 50% is considered

Solar photovoltaic applications seminar: design, installation and operation of small, stand-alone photovoltaic power systems

Energy Technology Data Exchange (ETDEWEB)

1980-07-01

This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.

Exergy analysis of photovoltaic solar collector

International Nuclear Information System (INIS)

Sopian, K.; Othman, M.Y.Hj.

1998-01-01

The exergy analysis (availability or second law analysis) is applied to the photovoltaic thermal solar collector. Photovoltaic thermal collector is a special type of solar collector where electricity and heat are produced simultaneously. The electricity produced from the photovoltaic thermal collector is all converted into useful work. The available quantity of the heat collected can readily be determined by taking into account both the quantity (heat quantity) and quality ( a function of temperature) of the thermal energy. Therefore, using the concept of exergy allows heat produced from the thermal collector and the electricity generated from the photovoltaic cells to be compared or to be evaluated on the basis of a common measure such as the effectiveness on solar energy collection or the total amount of available energy. In this paper, the effectiveness of solar energy collection is called combined photovoltaic thermal exergy efficiency. An experimental setup of a double pas photovoltaic thermal solar collector has been deigned, fabricated and tested. (author)

Development of small-scale photovoltaic systems; Le photovoltaique au coin de la rue

Energy Technology Data Exchange (ETDEWEB)

Anon.

2004-04-01

Small-scale photovoltaic installations are becoming competitive because the decrease in the price of solar panels is now combined with a drop in the electrical consumption levels of urban equipment. Emergency stop telephones and pay-and-display ticket machines for motorists have now become the most visible applications of photovoltaic technology. Solar installations of less than 150 W capacity are more and more present in the urban environment. (A.L.B.)

Turbulence convective heat transfer for cooling the photovoltaic cells

Science.gov (United States)

Arianmehr, Iman

Solar PV (photovoltaic) is a rapidly advancing renewable energy technology which converts sunlight directly into electricity. One of the outstanding challenges of the current PV technology is the reduction in its conversion efficiency with increasing PV panel temperature, which is closely associated with the increase in solar intensity and the ambient temperature surrounding the PV panels. To more effectively capture the available energy when the sun is most intense, significant efforts have been invested in active and passive cooling research over the last few years. While integrated cooling systems can lead to the highest total efficiencies, they are usually neither the most feasible nor the most cost effective solutions. This work examines some simple passive means of manipulating the prevailing wind turbulence to enhance convective heat transfer over a heated plate in a wind tunnel.

Distributed photovoltaic generation in Brazil: An economic viability analysis of small-scale photovoltaic systems in the residential and commercial sectors

International Nuclear Information System (INIS)

Holdermann, Claudius; Kissel, Johannes; Beigel, Jürgen

2014-01-01

This paper examines the economic viability of small-scale, grid-connected photovoltaics in the Brazilian residential and commercial sectors after the introduction of the net metering regulation in April 2012. This study uses the discounted cash flow method to calculate the specific investment costs that are necessary for photovoltaic systems to be economically viable for each of the 63 distribution networks in Brazil. We compare these values to the system costs that are estimated in the comprehensive study on photovoltaics that was developed by the Brazilian Association of Electric and Electronic Industries (ABINEE). In our calculation, we utilize the current electricity tariffs, including fees and taxes, which we obtained through telephone interviews and publicly available information. We obtained a second important parameter by simulating PV-systems with the program PV ⁎ Sol at the distribution company headquarters' locations. In our base case scenario that reflects the current situation, in none of the distribution networks photovoltaics is economically viable in either the commercial or residential sectors. We improved the environment for grid-connected photovoltaics in our scenarios by assuming both lower PV-system costs and a lower discount rate to determine the effect on photovoltaics viability. - Highlights: • We calculate the economic viability of photovoltaics in the residential and commercial sectors in Brazil. • The PV ⁎ Sol simulations are carried out at the headquarter locations for the 63 distribution companies. • Currently in none of the distribution networks, photovoltaics is economically viable in either the commercial or residential sectors. • We analyze how the variation of the specific investment costs and of the discount rate affects the economic viability

Performance study of heat-pipe solar photovoltaic/thermal heat pump system

International Nuclear Information System (INIS)

Chen, Hongbing; Zhang, Lei; Jie, Pengfei; Xiong, Yaxuan; Xu, Peng; Zhai, Huixing

2017-01-01

Highlights: • The testing device of HPS PV/T heat pump system was established by a finished product of PV panel. • A detailed mathematical model of heat pump was established to investigate the performance of each component. • The dynamic and static method was combined to solve the mathematical model of HPS PV/T heat pump system. • The HPS PV/T heat pump system was optimized by the mathematical model. • The influence of six factors on the performance of HPS PV/T heat pump system was analyzed. - Abstract: A heat-pipe solar (HPS) photovoltaic/thermal (PV/T) heat pump system, combining HPS PV/T collector with heat pump, is proposed in this paper. The HPS PV/T collector integrates heat pipes with PV panel, which can simultaneously generate electricity and thermal energy. The extracted heat from HPS PV/T collector can be used by heat pump, and then the photoelectric conversion efficiency is substantially improved because of the low temperature of PV cells. A mathematical model of the system is established in this paper. The model consists of a dynamic distributed parameter model of the HPS PV/T collection system and a quasi-steady state distributed parameter model of the heat pump. The mathematical model is validated by testing data, and the dynamic performance of the HPS PV/T heat pump system is discussed based on the validated model. Using the mathematical model, a reasonable accuracy in predicting the system’s dynamic performance with a relative error within ±15.0% can be obtained. The capacity of heat pump and the number of HPS collectors are optimized to improve the system performance based on the mathematical model. Six working modes are proposed and discussed to investigate the effect of solar radiation, ambient temperature, supply water temperature in condenser, PV packing factor, heat pipe pitch and PV backboard absorptivity on system performance by the validated model. It is found that the increase of solar radiation, ambient temperature and PV

Simulation of Solar Heat Pump Dryer Directly Driven by Photovoltaic Panels

Science.gov (United States)

Houhou, H.; Yuan, W.; Wang, G.

2017-05-01

This paper investigates a new type of solar heat pump dryer directly driven by photovoltaic panels. In order to design this system, a mathematical model has been established describing the whole drying process, including models of key components and phenomena of heat and mass transfer at the product layer and the air. The results of simulation at different drying air temperatures and velocities have been calculated and it indicate that the temperature of drying air is crucial external parameter compared to the velocity, with the increase of drying temperature from 45°C to 55°C, the product moisture content (Kg water/Kg dry product) decreased from 0.75 Kg/Kg to 0.3 Kg/Kg.

Recent progresses and achievements in photovoltaic-phase change material technology: A review with special treatment on photovoltaic thermal-phase change material systems

International Nuclear Information System (INIS)

Islam, M.M.; Pandey, A.K.; Hasanuzzaman, M.; Rahim, N.A.

2016-01-01

Highlights: • Broad summary of phase change materials based cooling for photovoltaic modules. • Compendium on phase change materials that are mostly used in photovoltaic systems. • Extension of heat availability period by 75–100% with phase change material. • Heat storage potential improves by 33–50% more with phase change material. • Future trend and move in photovoltaic thermal research. - Abstract: This communication lays out an appraisal on the recent works of phase change materials based thermal management techniques for photovoltaic systems with special focus on the so called photovoltaic thermal-phase change material system. Attempt has also been made to draw wide-ranging classification of both photovoltaic and photovoltaic thermal systems and their conventional cooling or heat harvesting methods developed so far so that feasible phase change materials application area in these systems can be pointed out. In addition, a brief literature on phase change materials with particular focus on their solar application has also been presented. Overview of the researches and studies establish that using phase change materials for photovoltaic thermal control is technically viable if some issues like thermal conductivity or phase stability are properly addressed. The photovoltaic thermal-phase change material systems are found to offer 33% (maximum 50%) more heat storage potential than the conventional photovoltaic-thermal water system and that with 75–100% extended heat availability period and around 9% escalation in output. Reduction in temperature attained with photovoltaic thermal-phase change material system is better than that with regular photovoltaic-thermal water system, too. Studies also show the potential of another emerging technology of photovoltaic thermal-microencapsulated phase change material system that makes use of microencapsulated phase change materials in thermal regulation. Future focus areas on photovoltaic thermal-phase change

Sustainable Heating, Cooling and Ventilation of a Plus-Energy House via Photovoltaic/Thermal Panels

DEFF Research Database (Denmark)

Kazanci, Ongun Berk; Skrupskelis, Martynas; Sevela, Pavel

2014-01-01

Present work addresses the HVAC and energy concerns of the Technical University of Denmark's house, Fold, for the competition Solar Decathlon Europe 2012. Various innovative solutions are investigated; photovoltaic/thermal (PV/T) panels, utilization of ground as a heat source/sink and phase change...... two separate systems. PV/T panels enable the house to perform as a plus-energy house. PV/T also yields to a solar fraction of 63% and 31% for Madrid and Copenhagen, respectively. The ground heat exchanger acts as the heat sink/source of the house. Free cooling enables the same cooling effect...

MATLAB Simulation of Photovoltaic and Photovoltaic/Thermal Systems Performance

Science.gov (United States)

Nasir, Farah H. M.; Husaini, Yusnira

2018-03-01

The efficiency of the photovoltaic reduces when the photovoltaic cell temperature increased due to solar irradiance. One solution is come up with the cooling system photovoltaic system. This combination is forming the photovoltaic-thermal (PV/T) system. Not only will it generate electricity also heat at the same time. The aim of this research is to focus on the modeling and simulation of photovoltaic (PV) and photovoltaic-thermal (PV/T) electrical performance by using single-diode equivalent circuit model. Both PV and PV/T models are developed in Matlab/Simulink. By providing the cooling system in PV/T, the efficiency of the system can be increased by decreasing the PV cell temperature. The maximum thermal, electrical and total efficiency values of PV/T in the present research are 35.18%, 15.56% and 50.74% at solar irradiance of 400 W/m2, mass flow rate of 0.05kgs-1 and inlet temperature of 25 °C respectively has been obtained. The photovoltaic-thermal shows that the higher efficiency performance compared to the photovoltaic system.

Enhancing Convective Heat Transfer over a Surrogate Photovoltaic Panel

Science.gov (United States)

Fouladi, Fama

This research is particularly focused on studying heat transfer enhancement of a photovoltaic (PV) panel by putting an obstacle at the panel's windward edge. The heat transfer enhancement is performed by disturbing the airflow over the surface and increasing the heat and momentum transfer. Different objects such as triangular, square, rectangular, and discrete rectangular ribs and partial grids were applied at the leading edge of a surrogate PV panel and flow and the heat transfer of the panel are investigated experimentally. This approach was selected to expand understanding of effect of these different objects on the flow and turbulence structures over a flat surface by analyzing the flow comprehensively. It is observed that, a transverse object at the plate's leading edge would cause some flow blockage in the streamwise direction, but at the same time creates some velocity in the normal and cross stream directions. In addition to that, the obstacle generates some turbulence over the surface which persists for a long downstream distance. Also, among all studied objects, discrete rectangular ribs demonstrate the highest heat transfer rate enhancement (maximum Nu/Nu0 of 1.5). However, ribs with larger gap ratios are observed to be more effective at enhancing the heat transfer augmentation at closer distances to the rib, while at larger downstream distances from the rib, discrete ribs with smaller gap ratios are more effective. Furthermore, this work attempted to recognize the most influential flow parameters on the heat transfer enhancement of the surface. It is seen that the flow structure over a surface downstream of an object (flow separation-reattachment behaviour) has a significant effect on the heat transfer enhancement trend. Also, turbulence intensities are the most dominant parameters in enhancing the heat transfer rate from the surface; however, flow velocity (mostly normal velocity) is also an important factor.

Double-pass photovoltaic / thermal (PV/T) solar collector with advanced heat transfer features

International Nuclear Information System (INIS)

Mohd Nazari Abu Bakar; Baharudin Yatim; Mohd Yusof Othman; Kamaruzzaman Sopian

2006-01-01

The use of PV/T in combination with concentrating reflectors has a potential to significantly increase power production from a given solar cell area. A prototype double-pass photovoltaic-thermal solar air collector with CPR and fins has been designed and fabricated and its performance over a range of operating conditions was studied. The absorber of the hybrid photovoltaic / thermal (PV/T) collector under investigation consists of an array of solar cells for generating electricity, compound parabolic concentrator (CPR) to increase the radiation intensity falling on the solar cells and fins attached to the back side of the absorber plate to improve heat transfer to the flowing air. The thermal, electrical and combined electrical and thermal efficiencies of the collector are presented and discussed

Impact of small-scale storage systems on the photovoltaic penetration potential at the municipal scale

Science.gov (United States)

Ramirez Camargo, Luis; Dorner, Wolfgang

2016-04-01

The yearly cumulated technical energy generation potential of grid-connected roof-top photovoltaic power plants is significantly larger than the demand of domestic buildings in sparsely populated municipalities in central Europe. However, an energy balance with cumulated annual values does not deliver the right picture about the actual potential for photovoltaics since these run on a highly variable energy source as solar radiation. The mismatch between the periods of generation and demand creates hard limitations for the deployment of the theoretical energy generation potential of roof-top photovoltaics. The actual penetration of roof-top photovoltaic is restricted by the energy quality requirements of the grid and/or the available storage capacity for the electricity production beyond the coverage of own demands. In this study we evaluate in how far small-scale storage systems can contribute to increment the grid-connected roof-top photovoltaic penetration in domestic buildings at a municipal scale. To accomplish this, we calculate, in a first step, the total technical roof-top photovoltaic energy generation potential of a municipality in a high spatiotemporal resolution using a procedure that relies on geographic information systems. Posteriorly, we constrain the set of potential photovoltaic plants to the ones that would be necessary to cover the total yearly demand of the municipality. We assume that photovoltaic plants with the highest yearly yield are the ones that should be installed. For this sub-set of photovoltaic plants we consider five scenarios: 1) no storage 2) one 7 kWh battery is installed in every building with a roof-top photovoltaic plant 3) one 10 kWh battery is installed in every building with a roof-top photovoltaic plant 4) one 7 kWh battery is installed in every domestic building in the municipality 5) one 10 kWh battery is installed in every domestic building in the municipality. Afterwards we evaluate the energy balance of the

Small heating reactors for local heating of communities

International Nuclear Information System (INIS)

Seifritz, W.

1985-08-01

The incentives to introduce relatively small heating reactors for local heating of communities are presented and the reasons why this vertically integrated energy system will meet the requirement of an emission - free substitution system are outlined. (author)

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

A happy marriage. In his private home, heating systems expert Ulrich Krausscombines photovoltaic power generation and geothermal heat; Eine glueckliche Verbindung. Heizungsfachmann Ulrich Krauss kombiniert in seinem Haus Photovoltaik und Erdwaerme

Energy Technology Data Exchange (ETDEWEB)

Simons, Kristina; Krause, Matthias B.

2010-11-15

The contribution presents a private home with photovoltaic cells installed on the garage roof and with geothermal heating. In spite of unfavourable boundary conditions, the solar modules produce more electric power than the geothermal heat pump consumes. (orig.)

Small-Molecule Organic Photovoltaic Modules Fabricated via Halogen-Free Solvent System with Roll-to-Roll Compatible Scalable Printing Method.

Science.gov (United States)

Heo, Youn-Jung; Jung, Yen-Sook; Hwang, Kyeongil; Kim, Jueng-Eun; Yeo, Jun-Seok; Lee, Sehyun; Jeon, Ye-Jin; Lee, Donmin; Kim, Dong-Yu

2017-11-15

For the first time, the photovoltaic modules composed of small molecule were successfully fabricated by using roll-to-roll compatible printing techniques. In this study, blend films of small molecules, BTR and PC 71 BM were slot-die coated using a halogen-free solvent system. As a result, high efficiencies of 7.46% and 6.56% were achieved from time-consuming solvent vapor annealing (SVA) treatment and roll-to-roll compatible solvent additive approaches, respectively. After successful verification of our roll-to-roll compatible method on small-area devices, we further fabricated large-area photovoltaic modules with a total active area of 10 cm 2 , achieving a power conversion efficiency (PCE) of 4.83%. This demonstration of large-area photovoltaic modules through roll-to-roll compatible printing methods, even based on a halogen-free solvent, suggests the great potential for the industrial-scale production of organic solar cells (OSCs).

Nanoscale structure, dynamics and power conversion efficiency correlations in small molecule and oligomer-based photovoltaic devices

Science.gov (United States)

Szarko, Jodi M.; Guo, Jianchang; Rolczynski, Brian S.; Chen, Lin X.

2011-01-01

Photovoltaic functions in organic materials are intimately connected to interfacial morphologies of molecular packing in films on the nanometer scale and molecular levels. This review will focus on current studies on correlations of nanoscale morphologies in organic photovoltaic (OPV) materials with fundamental processes relevant to photovoltaic functions, such as light harvesting, exciton splitting, exciton diffusion, and charge separation (CS) and diffusion. Small molecule photovoltaic materials will be discussed here. The donor and acceptor materials in small molecule OPV devices can be fabricated in vacuum-deposited, multilayer, crystalline thin films, or spin-coated together to form blended bulk heterojunction (BHJ) films. These two methods result in very different morphologies of the solar cell active layers. There is still a formidable debate regarding which morphology is favored for OPV optimization. The morphology of the conducting films has been systematically altered; using variations of the techniques above, the whole spectrum of film qualities can be fabricated. It is possible to form a highly crystalline material, one which is completely amorphous, or an intermediate morphology. In this review, we will summarize the past key findings that have driven organic solar cell research and the current state-of-the-art of small molecule and conducting oligomer materials. We will also discuss the merits and drawbacks of these devices. Finally, we will highlight some works that directly compare the spectra and morphology of systematically elongated oligothiophene derivatives and compare these oligomers to their polymer counterparts. We hope this review will shed some new light on the morphology differences of these two systems. PMID:22110870

Study of a pilot photovoltaic-electrolyser-fuel cell power system for a geothermal heat pump heated greenhouse and evaluation of the electrolyser efficiency and operational mode

Directory of Open Access Journals (Sweden)

Ileana Blanco

2014-11-01

Full Text Available The intrinsic factor of variability of renewable energy sources often limits their broader use. The photovoltaic solar systems can be provided with a power back up based on a combination of an electrolyser and a fuel cell stack. The integration of solar hydrogen power systems with greenhouse heating equipment can provide a possible option for powering stand-alone greenhouses. The aim of the research under development at the experimental farm of Department of Agro-Environmental Sciences of the University of Bari Aldo Moro is to investigate on the suitable solutions of a power system based on photovoltaic energy and on the use of hydrogen as energy vector, integrated with a ground source heat pump for greenhouse heating in a self sustained way. The excess energy produced by a purpose-built array of solar photovoltaic modules supplies an alkaline electrolyser; the produced hydrogen gas is stored in pressured storage tank. When the solar radiation level is insufficient to meet the heat pump power demand, the fuel cell starts converting the chemical energy stored by the hydrogen fuel into electricity. This paper reports on the description of the realised system. Furthermore the efficiency and the operational mode of the electrolyser were evaluated during a trial period characterised by mutable solar radiant energy. Anyway the electrolyser worked continuously in a transient state producing fluctuations of the hydrogen production and without ever reaching the steady-state conditions. The Faradic efficiency, evaluated by means of an empirical mathematic model, highlights that the suitable working range of the electrolyser was 1.5÷2.5 kW and then for hydrogen production more than 0.21 Nm3h–1.

Photovoltaic Wire, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

The Importance of End Groups for Solution-Processed Small-Molecule Bulk-Heterojunction Photovoltaic Cells.

Science.gov (United States)

Duan, Ruomeng; Cui, Yong; Zhao, Yanfei; Li, Chen; Chen, Long; Hou, Jianhui; Wagner, Manfred; Baumgarten, Martin; He, Chang; Müllen, Klaus

2016-05-10

End groups in small-molecule photovoltaic materials are important owing to their strong influence on molecular stability, solubility, energy levels, and aggregation behaviors. In this work, a series of donor-acceptor pentads (D2 -A-D1 -A-D2 ) were designed and synthesized, aiming to investigate the effect of the end groups on the materials properties and photovoltaic device performance. These molecules share identical central A-D1 -A triads (with benzodithiophene as D1 and 6-carbonyl-thieno[3,4-b]thiophene as A), but with various D2 end groups composed of alkyl-substituted thiophene (T), thieno[3,2-b]thiophene (TT), and 2,2'-bithiophene (BT). The results indicate a relationship between conjugated segment/alkyl chain length of the end groups and the photovoltaic performance, which contributes to the evolving molecular design principles for high efficiency organic solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlling the Morphology of BDTT-DPP-Based Small Molecules via End-Group Functionalization for Highly Efficient Single and Tandem Organic Photovoltaic Cells.

Science.gov (United States)

Kim, Ji-Hoon; Park, Jong Baek; Yang, Hoichang; Jung, In Hwan; Yoon, Sung Cheol; Kim, Dongwook; Hwang, Do-Hoon

2015-11-04

A series of narrow-band gap, π-conjugated small molecules based on diketopyrrolopyrrole (DPP) electron acceptor units coupled with alkylthienyl-substituted-benzodithiophene (BDTT) electron donors were designed and synthesized for use as donor materials in solution-processed organic photovoltaic cells. In particular, by end-group functionalization of the small molecules with fluorine derivatives, the nanoscale morphologies of the photoactive layers of the photovoltaic cells were successfully controlled. The influences of different fluorine-based end-groups on the optoelectronic and morphological properties, carrier mobilities, and the photovoltaic performances of these materials were investigated. A high power conversion efficiency (PCE) of 6.00% under simulated solar light (AM 1.5G) illumination has been achieved for organic photovoltaic cells based on a small-molecule bulk heterojunction system consisting of a trifluoromethylbenzene (CF3) end-group-containing oligomer (BDTT-(DPP)2-CF3) as the donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor. As a result, the introduction of CF3 end-groups has been found to enhance both the short circuit current density (JSC) and fill factor (FF). A tandem photovoltaic device comprising an inverted BDTT-(DPP)2-CF3:PC71BM cell and a poly(3-hexylthiophene) (P3HT):indene-C60-bisadduct (IC60BA)-based cell as the top and bottom cell components, respectively, showed a maximum PCE of 8.30%. These results provide valuable guidelines for the rational design of conjugated small molecules for applications in high-performance organic photovoltaic cells. Furthermore, to the best of our knowledge, this is the first report on the design of fluorine-functionalized BDTT-DPP-based small molecules, which have been shown to be a viable candidate for use in inverted tandem cells.

Distribution of absorbed heat in luminescent solar concentrator lightguides and effect of temperatures of mounted photovoltaic cells

NARCIS (Netherlands)

Rajkumar, V.A.; Weijers, C.; Debije, M.G.

2015-01-01

Polymer plates containing fluorescent dyes with photovoltaic cells attached to one or more edges have the potential to be used for solar light collection in the built environment. The heating of the polymer plates and the resulting effects this may have on the operating temperatures of the attached

Effects of Solar Photovoltaic Panels on Roof Heat Transfer

Science.gov (United States)

Dominguez, A.; Klessl, J.; Samady, M.; Luvall, J. C.

2010-01-01

Building Heating, Ventilation and Air Conditioning (HVAC) is a major contributor to urban energy use. In single story buildings with large surface area such as warehouses most of the heat enters through the roof. A rooftop modification that has not been examined experimentally is solar photovoltaic (PV) arrays. In California alone, several GW in residential and commercial rooftop PV are approved or in the planning stages. With the PV solar conversion efficiency ranging from 5-20% and a typical installed PV solar reflectance of 16-27%, 53-79% of the solar energy heats the panel. Most of this heat is then either transferred to the atmosphere or the building underneath. Consequently solar PV has indirect effects on roof heat transfer. The effect of rooftop PV systems on the building roof and indoor energy balance as well as their economic impacts on building HVAC costs have not been investigated. Roof calculator models currently do not account for rooftop modifications such as PV arrays. In this study, we report extensive measurements of a building containing a flush mount and a tilted solar PV array as well as exposed reference roof. Exterior air and surface temperature, wind speed, and solar radiation were measured and thermal infrared (TIR) images of the interior ceiling were taken. We found that in daytime the ceiling surface temperature under the PV arrays was significantly cooler than under the exposed roof. The maximum difference of 2.5 C was observed at around 1800h, close to typical time of peak energy demand. Conversely at night, the ceiling temperature under the PV arrays was warmer, especially for the array mounted flat onto the roof. A one dimensional conductive heat flux model was used to calculate the temperature profile through the roof. The heat flux into the bottom layer was used as an estimate of the heat flux into the building. The mean daytime heat flux (1200-2000 PST) under the exposed roof in the model was 14.0 Watts per square meter larger than

Photovoltaic power supply for appliances and small systems. Final report; Photovoltaik fuer Geraete und Kleinsysteme. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Roth, W.; Anton, L.; Benz, J.; Kaiser, R.; Kuhmann, J.; Puls, H.G.; Pfanner, N.; Schmidt, H.; Schulz, W.; Steinhueser, A.

2002-06-01

The economic prospects of PV power supply to appliances and small systems were investigated. The research project was aimed at improving the conditions for efficient development of appliances and small systems with photovoltaic power supply and autonomous systems not connected to the grid. Innovative products were developed and tested in cooperation with industrial organizations. The project is to help small and medium-sized organizations with a technological orientation and enhance technology transfer between science and industry.

Hybrid renewable energy system application for electricity and heat supply of a residential building

Directory of Open Access Journals (Sweden)

Nakomčić-Smaragdakis Branka B.

2016-01-01

Full Text Available Renewable and distributed energy systems could provide a solution to the burning issue of reliable and clean supply of energy, having in mind current state and future predictions for population growth and fossil fuel scarcity. Hybrid renewable energy systems are novelty in Serbia and warrant further detailed research. The aim of this paper is to analyze the application of renewable energy sources(RES for electricity and heat supply of a typical household in Serbia, as well as the cost-effectiveness of the proposed system. The influence of feed-in tariff change on the value of the investment is analyzed. Small, grid-connected hybrid system (for energy supply of a standard household, consisting of geothermal heat pump for heating/cooling, solar photovoltaic panels and small wind turbine for power supply is analyzed as a case study. System analysis was conducted with the help of RETScreen software. Results of techno-economics analysis have shown that investing in geothermal heat pump and photovoltaic panels is cost-effective, while that is not the case with small wind turbine.

A review of concentrated photovoltaic-thermal (CPVT) hybrid solar systems with waste heat recovery (WHR)

Institute of Scientific and Technical Information of China (English)

Xing Ju; Chao Xu; Zhirong Liao; Xiaoze Du; Gaosheng Wei; Zhifeng Wang; Yongping Yang

2017-01-01

In conventional photovoltaic (PV) systems,a large portion of solar energy is dissipated as waste heat since the generating efficiency is usually less than 30％.As the dissipated heat can be recovered for various applications,the wasted heat recovery concentrator PV/thermal (WHR CPVT) hybrid systems have been developed.They can provide both electricity and usable heat by combining thermal systems with concentrator PV (CPV) module,which dramatically improves the overall conversion efficiency of solar energy.This paper systematically and comprehensively reviews the research and development ofWHR CPVT systems.WHR CPVT systems with innovative design configurations,different theoretical evaluation models and experimental test processes for several implementations are presented in an integrated manner.We aim to provide a global point of view on the research trends,market potential,technical obstacles,and the future work which is required in the development of WHR CPVT technology.Possibly,it will offer a generic guide to the investigators who are interested in the study of WHR CPVT systems.

Battery charging characteristics in small scaled photovoltaic system using resonant DC-DC converter with electric isolation

International Nuclear Information System (INIS)

Isoda, H.; Kimura, G.; Shioya, M.

1990-01-01

The solar energy has been drawing attention of the whole world as a clean and infinite energy, since the globe resource, the globe ecology and so on came into question. The wide applications of the solar energy are being expected in a range from electric power plants to household systems. But the output power induced in the photovoltaic modules is influenced by an intensity of the solar radiation, a temperature of the solar cells and so on, so the various useful forms of the solar energy are being proposed for a purpose of stable power supply. a system described in this paper is a small scaled photovoltaic system with storage batteries. This paper describes the theoretical analyses of the photovoltaic system using a resonant DC-DC converter in order to clarify a desirable circuit condition, besides the experimental results of the battery charging characteristics are presented

Estimation of non-linear continuous time models for the heat exchange dynamics of building integrated photovoltaic modules

DEFF Research Database (Denmark)

Jimenez, M.J.; Madsen, Henrik; Bloem, J.J.

2008-01-01

This paper focuses on a method for linear or non-linear continuous time modelling of physical systems using discrete time data. This approach facilitates a more appropriate modelling of more realistic non-linear systems. Particularly concerning advanced building components, convective and radiati...... that a description of the non-linear heat transfer is essential. The resulting model is a non-linear first order stochastic differential equation for the heat transfer of the PV component....... heat interchanges are non-linear effects and represent significant contributions in a variety of components such as photovoltaic integrated facades or roofs and those using these effects as passive cooling strategies, etc. Since models are approximations of the physical system and data is encumbered...

Regulatory potential for increasing small scale grid connected photovoltaic (PV) deployment in Australia

International Nuclear Information System (INIS)

Sivaraman, Deepak; Horne, Ralph E.

2011-01-01

The last decade has seen significant innovation and change in regulatory incentives to support photovoltaic deployment globally. With high fossil fuel dependency and abundant solar resource availability in Australia, grid connected photovoltaics are a viable low carbon technology option in existing electricity grids. Drawing on international examples, the potential to increase grid PV deployment through government response and regulation is explored. For each renewable energy certificate (REC) earned by small scale photovoltaics until 2012, the market provides four additional certificates under the current banded renewable targets. Our analysis indicates that REC eligibility is not accurately estimated currently, and an energy model is developed to calculate the variance. The energy model estimates as much as 26% additional REC's to be obtained by a 3 kWp PV system, when compared to the currently used regulatory method. Moreover, the provision of REC's increases benefits to PV technologies, in the process distorting CO 2 abatement (0.21 tonne/REC) by 68%, when PV displaces peaking natural gas plants. Consideration of the secondary effects of a banded structure on emissions trading market is important in the context of designing a range of initiatives intended to support a transition to a low carbon electricity sector. - Research Highlights: →Grid connected photovoltaics hedge spikes in peak demand summer electricity prices. →Nationwide feed in tariff and new building regulations needed to increase PV deployment. →Australia has transitioned from a solar rebate to a banded solar credit structure. →The currently used regulatory deeming method underestimates REC eligibility by 27%. →The banded structure can potentially distort CO 2 abatement by as much as 68%.

High performance photovoltaic applications using solution-processed small molecules.

Science.gov (United States)

Chen, Yongsheng; Wan, Xiangjian; Long, Guankui

2013-11-19

Energy remains a critical issue for the survival and prosperity of humancivilization. Many experts believe that the eventual solution for sustainable energy is the use of direct solar energy as the main energy source. Among the options for renewable energy, photovoltaic technologies that harness solar energy offer a way to harness an unlimited resource and minimum environment impact in contrast with other alternatives such as water, nuclear, and wind energy. Currently, almost all commercial photovoltaic technologies use Si-based technology, which has a number of disadvantages including high cost, lack of flexibility, and the serious environmental impact of the Si industry. Other technologies, such as organic photovoltaic (OPV) cells, can overcome some of these issues. Today, polymer-based OPV (P-OPV) devices have achieved power conversion efficiencies (PCEs) that exceed 9%. Compared with P-OPV, small molecules based OPV (SM-OPV) offers further advantages, including a defined structure for more reproducible performance, higher mobility and open circuit voltage, and easier synthetic control that leads to more diversified structures. Therefore, while largely undeveloped, SM-OPV is an important emerging technology with performance comparable to P-OPV. In this Account, we summarize our recent results on solution-processed SM-OPV. We believe that solution processing is essential for taking full advantage of OPV technologies. Our work started with the synthesis of oligothiophene derivatives with an acceptor-donor-acceptor (A-D-A) structure. Both the backbone conjugation length and electron withdrawing terminal groups play an important role in the light absorption, energy levels and performance of the devices. Among those molecules, devices using a 7-thiophene-unit backbone and a 3-ethylrhodanine (RD) terminal unit produced a 6.1% PCE. With the optimized conjugation length and terminal unit, we borrowed from the results with P-OPV devices to optimize the backbone. Thus we

Experimental Studies on the Flammability and Fire Hazards of Photovoltaic Modules.

Science.gov (United States)

Yang, Hong-Yun; Zhou, Xiao-Dong; Yang, Li-Zhong; Zhang, Tao-Lin

2015-07-09

Many of the photovoltaic (PV) systems on buildings are of sufficiently high voltages, with potential to cause or promote fires. However, research about photovoltaic fires is insufficient. This paper focuses on the flammability and fire hazards of photovoltaic modules. Bench-scale experiments based on polycrystalline silicon PV modules have been conducted using a cone calorimeter. Several parameters including ignition time ( t ig ), mass loss, heat release rate (HRR), carbon monoxide (CO) and carbon dioxide (CO₂) concentration, were investigated. The fire behaviours, fire hazards and toxicity of gases released by PV modules are assessed based on experimental results. The results show that PV modules under tests are inflammable with the critical heat flux of 26 kW/m². This work will lead to better understanding on photovoltaic fires and how to help authorities determine the appropriate fire safety provisions for controlling photovoltaic fires.

The photovoltaic ambitious of EDF

International Nuclear Information System (INIS)

Houot, G.

2008-01-01

Added to the wind energy, EDF develops the photovoltaic by its subsidiaries EDF Energies Nouvelles, for the big power plants and EDF Energies Nouvelles Reparties centralized on the market of small installations for roofs. The author analyzes the society management and project concerning the photovoltaic development. (A.L.B.)

Photovoltaics information user study

Energy Technology Data Exchange (ETDEWEB)

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

1980-10-01

The results of a series of telephone interviews with groups of users of information on photovoltaics (PV) 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. It covers these technological areas: photovoltaics, passive solar heating and cooling, active solar heating and cooling, biomass energy, solar thermal electric power, solar industrial and agricultural process heat, wind energy, ocean energy, and advanced energy storage. 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 PV groups respondents are analyzed in this report: DOE-Funded Researchers, Non-DOE-Funded Researchers, Researchers Working for Manufacturers, Representatives of Other Manufacturers, Representatives of Utilities, Electric Power Engineers, and Educators.

Socioeconomic impact of photovoltaic power at Schuchuli, Arizona

Science.gov (United States)

Bahr, D.; Garrett, B. G.; Chrisman, C.

1980-01-01

The social and economic impact of photovoltaic power on a small, remote native American village is studied. Village history, group life, energy use in general, and the use of photovoltaic-powered appliances are discussed. No significant impacts due to the photovoltaic power system were observed.

Solar photovoltaic/thermal residential experiment. Phase I. Final report

Energy Technology Data Exchange (ETDEWEB)

Darkazalli, G.

1980-07-01

Month-by-month energy transfer data between an occupied residence and its energy supply systems are presented. The data were obtained during the first phase of photovoltaic/thermal residential research conducted at the University of Texas at Arlington/Solar Energy Research Facility. This research was part of the US Department of Energy Photovoltaic/Thermal Project managed by the M.I.T. Lincoln Laboratory. Energy transfer data are divided into different categories depending on how the energy is consumed. Energy transfers between some system components are also categorized. These components include a flat-plate thermal collector array, a flat-plate photovoltaic array, a dc-to-ac inverter, thermal storage tanks, and a series heat pump. System operations included directing surplus electrical energy (generated by the photovoltaic array) into the local utility grid. The heat pump used off-peak utility power to chill water during the cooling season.

Optimal coordinated scheduling of combined heat and power fuel cell, wind, and photovoltaic units in micro grids considering uncertainties

International Nuclear Information System (INIS)

Bornapour, Mosayeb; Hooshmand, Rahmat-Allah; Khodabakhshian, Amin; Parastegari, Moein

2016-01-01

In this paper, a stochastic model is proposed for coordinated scheduling of combined heat and power units in micro grid considering wind turbine and photovoltaic units. Uncertainties of electrical market price; the speed of wind and solar radiation are considered using a scenario-based method. In the method, scenarios are generated using roulette wheel mechanism based on probability distribution functions of input random variables. Using this method, the probabilistic specifics of the problem are distributed and the problem is converted to a deterministic one. The type of the objective function, coordinated scheduling of combined heat and power, wind turbine, and photovoltaic units change this problem to a mixed integer nonlinear one. Therefore to solve this problem modified particle swarm optimization algorithm is employed. The mentioned uncertainties lead to an increase in profit. Moreover, the optimal coordinated scheduling of renewable energy resources and thermal units in micro grids increase the total profit. In order to evaluate the performance of the proposed method, its performance is executed on modified 33 bus distributed system as a micro grid. - Highlights: • Stochastic model is proposed for coordinated scheduling of renewable energy sources. • The effect of combined heat and power is considered. • Maximizing profits of micro grid is considered as objective function. • Considering the uncertainties of problem lead to profit increasing. • Optimal scheduling of renewable energy sources and thermal units increases profit.

Experimental Studies on the Flammability and Fire Hazards of Photovoltaic Modules

Directory of Open Access Journals (Sweden)

Hong-Yun Yang

2015-07-01

Full Text Available Many of the photovoltaic (PV systems on buildings are of sufficiently high voltages, with potential to cause or promote fires. However, research about photovoltaic fires is insufficient. This paper focuses on the flammability and fire hazards of photovoltaic modules. Bench-scale experiments based on polycrystalline silicon PV modules have been conducted using a cone calorimeter. Several parameters including ignition time (tig, mass loss, heat release rate (HRR, carbon monoxide (CO and carbon dioxide (CO2 concentration, were investigated. The fire behaviours, fire hazards and toxicity of gases released by PV modules are assessed based on experimental results. The results show that PV modules under tests are inflammable with the critical heat flux of 26 kW/m2. This work will lead to better understanding on photovoltaic fires and how to help authorities determine the appropriate fire safety provisions for controlling photovoltaic fires.

Heating load of buildings. Room heat from decentralized renewable electricity; Heizlast von Gebaeuden. Raumwaerme aus dezentral erneuerbarem Strom

Energy Technology Data Exchange (ETDEWEB)

Hartmann, Frank

2013-10-15

If one would like to get the heating load of a building by using peripheral generated electrical energy from photovoltaics or small wind power, one must deal with both the specific building, as well as the heating load, the heating temperature limit and the differentiation of specific heating period for the building. Here, a ground source heat pump with an intelligent energy storage system seems to be the first choice. [German] Moechte man mit dezentral erzeugter elektrischer Energie aus Photovoltaik oder Kleinst-Windkraft die Heizlast eines Gebaeudes besorgen, muss man sich sowohl mit dem spezifischen Gebaeude, als auch mit der Heizlast, der Heizgrenztemperatur und der Differenzierung der spezifischen Heizperiode fuer das Gebaeude auseinandersetzen. Dabei scheint eine erdgekoppelte Waermepumpe mit einem intelligenten Speichersystem die erste Wahl.

A profitability assessment of small-scale photovoltaic systems in an electricity market without subsidies

International Nuclear Information System (INIS)

Cucchiella, Federica; D’Adamo, Idiano; Gastaldi, Massimo

2016-01-01

Highlights: • Net Present Value varies from 437 to 624 € per kW installed. • Discounted Payback Time ranges from 4 years to 6 years. • Reduction of emissions of 21 tCO 2 eq for each kW installed during the 20 years. • Break-even point of increase of self-consumption varies from 6% to 13%. • The opportunity to keep a 50% of fiscal deduction for 5 years. - Abstract: The installation of photovoltaic power plants in 2015 compared to 2014 registered a growth of 25.6%, reaching a cumulative power equal to 229 GW. In developed solar markets, as many European countries, the sector is pushed by the alignment between the electric power demanded and the one offered. Consequently, self-consumption makes consumers active players of the energy transition. Italy is evaluated as a case study in this paper, in fact is the first country in the world where solar energy contributes largely to the national energetic demand. This paper aims to evaluate photovoltaic systems in residential sector without subsidies. Economic and environmental results are proposed and the indicators used are Net Present Value, Discounted Payback Time and Reduction in the Emissions of Carbon Dioxide. Three sizes (3 kW, 6 kW and 20 kW) are evaluated. In addition, a sensitivity analysis of critical variables (investment cost, annual electricity purchase price, annual electricity sales price, opportunity cost, tax deduction unitary, period of fiscal deduction, average annual insolation and percentage of energy self-consumption) demonstrates the robustness of the economic results. Also for environmental evaluation, alternative scenarios are proposed varying the value of emissions released by source energy analysed (photovoltaic, coal, oil and gas). Economic and environmental results suggest that small-scale photovoltaic systems can support the transition towards a sustainable energy mix.

Fabrication and performance analysis of concentrated hybrid photovoltaic system

Directory of Open Access Journals (Sweden)

Murthy Krishna

2018-01-01

Full Text Available Sun is the most important source of renewable source of energy. During the past few decades there has been an ever-increasing interest in Photovoltaic (PV cells as it directly converts solar radiation into electricity. This paper involves the performance study of photovoltaic system under concentrated solar radiation. The main problem with the concentration solar energy is the drastic increase in temperature of the photovoltaic module resulting in a decrease in performance efficiency of the system. This problem of overheating of the system can be overcome by providing cooling which would ensure operation of the module in the optimal temperature range. Hence, the setup would function as a hybrid model serving the dual purpose of power generation while also utilizing the waste heat for water heating applications. The experimental set up consist of a novel arrangement of concentrator and reflector and the cooling system. The Hybrid Photovoltaic System was repeatedly tested under real time conditions on several days. A comparison was drawn between the results obtained from direct exposure of a standard photovoltaic module to that obtained from the hybrid system in order to better understand the improvement in performance parameters. The study shown a significant improvement of output of standard photovoltaic module under the concentrated solar radiation.

Comparative Study of Two New Configurations of Solar Photovoltaic Thermal Collectors

OpenAIRE

K. Touafek; A. Khelifa; E. H. Khettaf; A. Embarek

2013-01-01

Hybrid photovoltaic thermal (PV/T) solar system comprises a solar collector which is disposed on photovoltaic solar cells. The disadvantage of a conventional photovoltaic cell is that its performance decreases as the temperature increases. Indeed, part of the solar radiation is converted into electricity and is dissipated as heat, increasing the temperature of the photovoltaic cell with respect to the ambient temperature. The objective of this work is to study experimentally and implement a h...

UPVG efforts to commercialize photovoltaics

International Nuclear Information System (INIS)

Serfass, J.A.; Wills, B.N.

1995-01-01

The Utility PhotoVoltaic Group (UPVG) was formed in October of 1992 with a mission to accelerate the use of cost-effective small-scale and emerging grid-connected applications of photovoltaics for the benefit of electric utilities and their customers. The UPVG is now implementing a program to install up to 50 megawatts of photovoltaics in small-scale and grid-connected applications. This program, called TEAM-UP, is a partnership of the US electric utility industry and the US Department of Energy to help develop utility PV markets. TEAM-UP is a utility-directed program to significantly increase utility PV experience by promoting installations of utility PV systems. Two primary program areas are proposed for TEAM-UP: (1) Small-Scale Applications (SSA)--an initiative to aggregate utility purchases of small-scale, grid-independent applications; and (2) Grid-Connected Applications (GCA)--an initiative to identify and competitively award cost-sharing contracts for grid-connected PV systems with high market growth potential, or collective purchase programs involving multiple buyers. This paper describes these programs and outlines the schedule, the procurement status, and the results of the TEAM-UP process

Photovoltaic conversion in Austria: Inventory 1994

International Nuclear Information System (INIS)

Faninger, G.

1995-05-01

On January 1, 1995 photovoltaic systems with a maxiumum capacity of about 1063 kW (peak) were installed in Austria. 48% of the photovoltaic systems are connected with the grid, 24% are stand-alone systems and about 28% are small systems (<200 W) for different applications. (author)

The role of photovoltaics in reducing greenhouse gas emissions

International Nuclear Information System (INIS)

Blakers, A.; Green, M.; Leo, T.; Outhred, H.; Robins, B.

1991-01-01

This report examines the opportunities that will arise for the Australian photovoltaic industry if external costs of energy conversion are internalized. Such external costs include local pollution, resource depletion and the emission of greenhouse gases. Generation of electricity from photovoltaic (PV) modules is now a widely accepted environmentally friendly energy conversion technology. At present, high capital costs restricts its use to the provision of small amounts of power in remote areas, where it successfully competes against small diesel generators. However, as costs continue to decline, photovoltaic systems will compete successfully with progressively larger diesel-electric systems in Australia, in a market worth more than a billion dollars. Direct competition with electricity generated by conventional means for state grids is possible after the turn of the century. The present Australian photovoltaic industry is export oriented. The market for PV systems in poor rural areas in Asia is potentially very large. The cost of supplying small quantities of electricity to millions of rural households is high, making photovoltaics a competitive option. It is concluded that the Australian photovoltaic industry is in a good position to participate in the growth in this market sector. 48 refs., 28 tabs., 18 figs., ills

Small photovoltaic setup for the air conditioning system

Directory of Open Access Journals (Sweden)

Masiukiewicz Maciej

2017-01-01

Full Text Available The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES. The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system. Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

Small photovoltaic setup for the air conditioning system

Science.gov (United States)

Masiukiewicz, Maciej

2017-10-01

The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES). The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV) to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system). Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

Reliability and cost evaluation of small isolated power systems containing photovoltaic and wind energy

Science.gov (United States)

Karki, Rajesh

Renewable energy application in electric power systems is growing rapidly worldwide due to enhanced public concerns for adverse environmental impacts and escalation in energy costs associated with the use of conventional energy sources. Photovoltaics and wind energy sources are being increasingly recognized as cost effective generation sources. A comprehensive evaluation of reliability and cost is required to analyze the actual benefits of utilizing these energy sources. The reliability aspects of utilizing renewable energy sources have largely been ignored in the past due the relatively insignificant contribution of these sources in major power systems, and consequently due to the lack of appropriate techniques. Renewable energy sources have the potential to play a significant role in the electrical energy requirements of small isolated power systems which are primarily supplied by costly diesel fuel. A relatively high renewable energy penetration can significantly reduce the system fuel costs but can also have considerable impact on the system reliability. Small isolated systems routinely plan their generating facilities using deterministic adequacy methods that cannot incorporate the highly erratic behavior of renewable energy sources. The utilization of a single probabilistic risk index has not been generally accepted in small isolated system evaluation despite its utilization in most large power utilities. Deterministic and probabilistic techniques are combined in this thesis using a system well-being approach to provide useful adequacy indices for small isolated systems that include renewable energy. This thesis presents an evaluation model for small isolated systems containing renewable energy sources by integrating simulation models that generate appropriate atmospheric data, evaluate chronological renewable power outputs and combine total available energy and load to provide useful system indices. A software tool SIPSREL+ has been developed which generates

Electrical research on solar cells and photovoltaic materials

Science.gov (United States)

Orehotsky, J.

1984-01-01

The flat-plate solar cell array program which increases the service lifetime of the photovoltaic modules used for terrestrial energy applications is discussed. The current-voltage response characteristics of the solar cells encapsulated in the modules degrade with service time and this degradation places a limitation on the useful lifetime of the modules. The most desirable flat-plate array system involves solar cells consisting of highly polarizable materials with similar electrochemical potentials where the cells are encapsulated in polymers in which ionic concentrations and mobilities are negligibly small. Another possible mechanism limiting the service lifetime of the photovoltaic modules is the gradual loss of the electrical insulation characteristics of the polymer pottant due to water absorption or due to polymer degradation from light or heat effects. The mechanical properties of various polymer pottant materials and of electrochemical corrosion mechanisms in solar cell material are as follows: (1) electrical and ionic resistivity; (2) water absorption kinetics and water solubility limits; and (3) corrosion characterization of various metallization systems used in solar cell construction.

Modelling the heat dynamics of a monitored Test Reference Environment for Building Integrated Photovoltaic systems using stochastic differential equations

DEFF Research Database (Denmark)

Lodi, C.; Bacher, Peder; Cipriano, J.

2012-01-01

reduce the ventilation thermal losses of the building by pre-heating the fresh air. Furthermore, by decreasing PV module temperature, the ventilation air heat extraction can simultaneously increase electrical and thermal energy production of the building. A correct prediction of the PV module temperature...... and heat transfer coefficients is fundamental in order to improve the thermo-electrical production.The considered grey-box models are composed of a set of continuous time stochastic differential equations, holding the physical description of the system, combined with a set of discrete time measurement......This paper deals with grey-box modelling of the energy transfer of a double skin Building Integrated Photovoltaic (BIPV) system. Grey-box models are based on a combination of prior physical knowledge and statistics, which enable identification of the unknown parameters in the system and accurate...

Method of calculating heat transfer in furnaces of small power

Directory of Open Access Journals (Sweden)

Khavanov Pavel

2016-01-01

Full Text Available This publication presents the experiences and results of generalization criterion equation of importance in the analysis of the processes of heat transfer and thermal calculations of low-power heat generators cooled combustion chambers. With generalizing depending estimated contribution of radiation and convective heat transfer component in the complex for the combustion chambers of small capacity boilers. Determined qualitative and quantitative dependence of the integrated radiative-convective heat transfer from the main factors working combustion chambers of small volume.

The Effects of Cells Temperature Increment and Variations of Irradiation for Monocrystalline Photovoltaic

Science.gov (United States)

Fuad Rahman Soeharto, Faishal; Hermawan

2017-04-01

Photovoltaic cell technology has been developed to meet the target of 17% Renewable Energy in 2025 accordance with Indonesia Government Regulation No. 5 2006. Photovoltaic cells are made of semiconductor materials, namely silicon or germanium (p-n junction). These cells need the light that comes from solar irradiation which brings energy photons to convert light energy into electrical energy. It is different from the solar heater that requires heat energy or thermal of sunlight that is normally used for drying or heating water. Photovoltaic cells requires energy photons to perform the energy conversion process, the photon energy can be derived from sunlight. Energy photon is taken from the sun light along with the advent of heat due to black-body radiation, which can lead to temperature increments of photovoltaic cells. Increment of 1°C can decreased photovoltaic cell voltage of up to 2.3 mV per cell. In this research, it will be discuss the analysis of the effect of rising temperatures and variations of irradiation on the type monocrystalline photovoltaic. Those variation are analyzed, simulated and experiment by using a module of experiment. The test results show that increment temperature from 25° C to 80° C at cell of photovoltaic decrease the output voltage of the photovoltaic cell at 4.21 V, and it also affect the power output of the cell which decreases up to 0.7523 Watt. In addition, the bigger the value of irradiation received by cell at amount of 1000 W / m2, produce more output power cells at the same temperature.

SOFAS market inquiry 1998. Solar collectors and photovoltaic modules in the year 1998

International Nuclear Information System (INIS)

Nordmann, T.

1999-04-01

Beginning 1984, the Swiss Professional Association of Solar Energy Firms (SOFAS) collects data on solar collector and photovoltaic module sales in Switzerland. The data enter the 'Swiss statistics of renewable energy sources' in the annual report of the action programme 'Energy 2000' as well as the 'General energy statistics' of the Swiss government. In this way, the total energy output of solar heating systems (for domestic hot water preparation, space heating, swimming pool heating, and hay drying) as well as that of photovoltaic systems is available since 1993 in Switzerland. For years, the installed collector and module area is growing continuously. Especially for photovoltaics the subsidy programme of the government has a clear impact on the market tabs., figs [de

The Swiss heating reactor (SHR) for district heating of small communities

International Nuclear Information System (INIS)

Burgsmueller, P.; Jacobi, A.Jr.; Jaeger, J.F.; Klaentschi, M.J.; Seifritz, W.; Vuillemier, F.; Wegmann, F.

1987-01-01

With fossil fuel running out in a foreseeable future, it is essential to develop substitution strategies. Some 40-50 % of the heat demand in industrial countries is below 120 degrees C, for space heating and warm water production, causing a corresponding fraction of air pollution by SO 2 and to a lesser extent NO x if fossil fuels are used. Yet, contemporary LWR technology makes it feasible to supply a district heating network without basically new reactor development. Units in the power range 10-50 MW are most suitable for Switzerland, both in respect of network size and of the democratic decision making structure. A small BWR for heating purpose is being developed by parts of the Swiss Industry and the Swiss Federal Institute for Reactor Research (EIR). The economic target of 100-120 SFr/MWh heat at the consumer's seems achievable. (author)

Byproduct mineral commodities used for the production of photovoltaic cells

Science.gov (United States)

Bleiwas, Donald I.

2010-01-01

Rising fossil fuel costs, environmental concerns relating to global climate change, and Government policy to signifcantly increase our Nation's energy independence have placed greater emphasis on the generation of electricity from renewable sources, such as the Sun (light and heat), water, and wind, which for all intents and purposes are inexhaustible resources. Although the total amount of electricity generated from the direct conversion of sunlight through photovoltaic cells is relatively small compared with that from other forms of renewable energy, the rate of growth in the sector is signifcant. The total value of energy of photovoltaic cells produced worldwide increased to nearly 7 gigawatts (GW) in 2008 from 45 megawatts (MW) in 1990, a compound annual growth rate of about 30 percent. In the United States, manufacturing of photovoltaic cells has grown exponentially to about 480 MW in 2008, accounting for 6 percent of world production, from less than 10 MW of photovoltaic capacity in 1990 (Benner, 2007; U.S. Department of Energy, Energy Information Administration, 2010), a compound annual growth rate of approxi-mately 23 percent. A production capacity of 1 GW of electricity [or 8,760 gigawatthours1 (GWh)] is equivalent to the annual electricity requirements for roughly 800,000 average households in the United States (U.S. Department of Energy, Energy Information Administration, 2010). This estimate does not include losses of electricity, such as during transmission through power lines.

A Wearable All-Solid Photovoltaic Textile.

Science.gov (United States)

Zhang, Nannan; Chen, Jun; Huang, Yi; Guo, Wanwan; Yang, Jin; Du, Jun; Fan, Xing; Tao, Changyuan

2016-01-13

A solution is developed to power portable electronics in a wearable manner by fabricating an all-solid photovoltaic textile. In a similar way to plants absorbing solar energy for photosynthesis, humans can wear the as-fabricated photovoltaic textile to harness solar energy for powering small electronic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental Performance Investigation of Photovoltaic/Thermal (PV–T System

Directory of Open Access Journals (Sweden)

Bakir C.

2013-04-01

Full Text Available Photovoltaic solar cells convert light energy from the sun into electricity. Photovoltaic cells are produced by semi-conducting materials to convert the energy into electricity and during this process heat is absorbed by the solar radiation. This heat causes a loss of electricity generation efficiencies.In this study, an experimental setup was designed and established to test two separate photovoltaic panel systems with alone PV and with water cooling system PV/T to examine the heat effect on PV systems. The absorbed heat energy behind the photovoltaic cell's surface in insulated ambient was removed by means of a water cooling system and the tests for both systems were simultaneously performed along the July 2011. It is found that without active water cooling, the temperature of the PV module was higher during day time and solar cells could only achieve around 8% conversion efficiency. On the other hand, when the PV module was operated with active water cooling condition, the temperature dropped significantly, leading to an increase in the efficiency of solarcells as much as 13.6%. Gained from absorbed solar heat and maximum thermal conversion efficiencies of the system are determined as 49% and 51% for two different mass flow rates. It is observed that water flow rate is effective on the increasing the conversion efficiency as well as absorption and transitionrates of cover glass in PV/T (PV–Thermal collector, the insulation material and cell efficiency. As a conclusion, the conversion efficiency of the PV system with water cooling might be improved on average about 10%. Therefore, it is recommended that PV system should be designed with most efficient type cooling system to enhance the efficiency and to decrease the payback period.

Modular assembly of a photovoltaic solar energy receiver

Science.gov (United States)

Graven, Robert M.; Gorski, Anthony J.; Schertz, William W.; Graae, Johan E. A.

1978-01-01

There is provided a modular assembly of a solar energy concentrator having a photovoltaic energy receiver with passive cooling. Solar cell means are fixedly coupled to a radiant energy concentrator. Tension means bias a large area heat sink against the cell thereby allowing the cell to expand or contract with respect to the heat sink due to differential heat expansion.

Reuse of the Reflective Light and the Recycle Heat Energy in Concentrated Photovoltaic System

Directory of Open Access Journals (Sweden)

Hsin-Chien Chen

2013-01-01

Full Text Available A complex solar unit with microcrystalline silicon solar cells placed around the centered GaAs triple junction solar cell has been proposed and carried out. With the same illumination area and intensity, the total resultant power shows that the excess microcrystalline silicon solar cells increase the total output power by 13.2% by absorbing the reflective light from the surface of optical collimators. Furthermore, reusing the residual heat energy generated from the above-mentioned mechanism helps to increase the output power by around 14.1%. This mechanism provides a simple method to enhance the utility rate of concentrated photovoltaic (CPV system. Such concept can be further applied to the aerospace industry and the development of more efficient CPV solar energy applications.

Experimental Assessment of a Helical Coil Heat Exchanger Operating at Subcritical and Supercritical Conditions in a Small-Scale Solar Organic Rankine Cycle

Directory of Open Access Journals (Sweden)

Marija Lazova

2017-05-01

Full Text Available In this study, the performance of a helical coil heat exchanger operating at subcritical and supercritical conditions is analysed. The counter-current heat exchanger was specially designed to operate at a maximal pressure and temperature of 42 bar and 200 °C, respectively. The small-scale solar organic Rankine cycle (ORC installation has a net power output of 3 kWe. The first tests were done in a laboratory where an electrical heater was used instead of the concentrated photovoltaic/thermal (CPV/T collectors. The inlet heating fluid temperature of the water was 95 °C. The effects of different parameters on the heat transfer rate in the heat exchanger were investigated. Particularly, the performance analysis was elaborated considering the changes of the mass flow rate of the working fluid (R-404A in the range of 0.20–0.33 kg/s and the inlet pressure varying from 18 bar up to 41 bar. Hence, the variation of the heat flux was in the range of 5–9 kW/m2. The results show that the working fluid’s mass flow rate has significant influence on the heat transfer rate rather than the operational pressure. Furthermore, from the comparison between the experimental results with the heat transfer correlations from the literature, the experimental results fall within the uncertainty range for the supercritical analysis but there is a deviation of the investigated subcritical correlations.

International Photovoltaic Program Plan

Energy Technology Data Exchange (ETDEWEB)

Costello, D.; Koontz, R.; Posner, D.; Heiferling, P.; Carpenter, P.; Forman, S.; Perelman, L.

1979-12-01

The International Photovoltaics Program Plan is in direct response to the Solar Photovoltaic Energy Research, Development, and Demonstration Act of 1978 (PL 95-590). As stated in the Act, the primary objective of the plan is to accelerate the widespread use of photovoltaic systems in international markets. Benefits which could result from increased international sales by US companies include: stabilization and expansion of the US photovoltaic industry, preparing the industry for supplying future domestic needs; contribution to the economic and social advancement of developing countries; reduced world demand for oil; and improvements in the US balance of trade. The plan outlines programs for photovoltaic demonstrations, systems developments, supplier assistance, information dissemination/purchaser assistance, and an informaion clearinghouse. Each program element includes tactical objectives and summaries of approaches. A program management office will be established to coordinate and manage the program plan. Although the US Department of Energy (DOE) had the lead responsibility for preparing and implementing the plan, numerous federal organizations and agencies (US Departments of Commerce, Justice, State, Treasury; Agency for International Development; ACTION; Export/Import Bank; Federal Trade Commission; Small Business Administration) were involved in the plan's preparation and implementation.

A pulse-width modulated, high reliability charge controller for small photovoltaic systems

Energy Technology Data Exchange (ETDEWEB)

Gerken, K. [Morningstar Corp., Olney, MD (United States); Welsh, D. [Morningstar Corp., Encinitas, CA (United States)

1997-02-01

This report presents the results of a development effort to design, test and begin production of a new class of small photovoltaic (PV) charge controllers. Sandia National Laboratories provided technical support, test data and financial support through a Balance-of-System Development contract. One of the objectives of the development was to increase user confidence in small PV systems by improving the reliability and operating life of the system controllers. Another equally important objective was to improve the economics of small PV systems by extending the battery lifetimes. Using new technology and advanced manufacturing techniques, these objectives were accomplished. Because small stand-alone PV systems account for over one third of all PV modules shipped, the positive impact of improving the reliability and economics of PV systems in this market segment will be felt throughout the industry. The results of verification testing of the new product are also included in this report. The initial design goals and specifications were very aggressive, but the extensive testing demonstrates that all the goals were achieved. Production of the product started in May at a rate of 2,000 units per month. Over 40 Morningstar distributors (5 US and 35 overseas) have taken delivery in the first 2 months of shipments. Initial customer reactions to the new controller have been very favorable.

Dynamic of small photovoltaic systems

Science.gov (United States)

Mehrmann, A.; Kleinkauf, W.; Pigorsch, W.; Steeb, H.

The results of 1.5 yr of field-testing of two photovoltaic (PV) power plants, one equipped with an electrolyzer and H2 storage, are reported. Both systems were interconnected with the grid and featured the PV module, a power conditioning unit, ac and dc load connections, and control units. The rated power of both units was 100 Wp. The system with electrolysis was governed by control laws which maximized the electrolyzer current. The tests underscored the preference for a power conditioning unit, rather than direct output to load connections. A 1 kWp system was developed in a follow-up program and will be tested in concert with electrolysis and interconnection with several grid customers. The program is geared to eventual development of larger units for utility-size applications.

A new topology to mitigate the effect of shading for small photovoltaic installations in rural sub-Saharan Africa

International Nuclear Information System (INIS)

Ubisse, A.; Sebitosi, A.

2009-01-01

Many field researchers have in the past grappled with the problems of energy loss and panel damage as a result of shading and staining of PV panels after installation. A number of solutions have been proposed to try and minimize the effects of this problem in the field. The problem with all these solutions is that they address inter-panel connection topologies for very large installations. No particular attention has been paid to the topologies of individual panels. In sub-Saharan Africa most installations are single panel solar home systems and therefore small shading can result in an entire installation being disabled. This paper aims to study the effect of shading and staining on photovoltaic modules and propose a new topology that will reduce the effect of shading on the performance of individual photovoltaic modules.

Modeling the thermal absorption factor of photovoltaic/thermal combi-panels

NARCIS (Netherlands)

Santbergen, R.; Zolingen, van R.J.C.

2006-01-01

In a photovoltaic/thermal combi-panel solar cells generate electricity while residual heat is extracted to be used for tap water heating or room heating. In such a panel the entire solar spectrum can be used in principle. Unfortunately long wavelength solar irradiance is poorly absorbed by the

The Economics of Connecting of Small Buildings to Geothermal District Heating Systems

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin

2003-03-01

Many of the communities co-located with geothermal resources are very small and as a result the buildings they contain tend to be small as well. Generally, small buildings (10,000 ft2) use heating systems which are not hot water based. Since geothermal district heating systems deliver hot water, the costs associated with the conversion of small building heating systems to use hot water for heating is an issue of great influence in terms of the potential development of such systems. This paper examines the typical retrofit costs associated with conversion of small buildings and the level of savings necessary to attract the interest of owners. In general, the prospects for connection of such buildings based only on energy savings is not positive.

The economics of connecting of small buildings to geothermal district heating systems

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin

2001-01-01

Many of the communities co-located with geothermal resources are very small and as a result the buildings they contain tend to be small as well. Generally, small buildings (10,000 ft2) use heating systems which are not hot water based. Since geothermal district heating systems deliver hot water, the costs associated with the conversion of small building heating systems to use hot water for heating is an issue of great influence in terms of the potential development of such systems. This paper examines the typical retrofit costs associated with conversion of small buildings and the level of savings necessary to attract the interest of owners. In general, the prospects for connection of such buildings based only on energy savings is not positive.

Natural Flow Air Cooled Photovoltaics

Science.gov (United States)

Tanagnostopoulos, Y.; Themelis, P.

2010-01-01

Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. We performed experiments using a prototype based on three silicon photovoltaic modules placed in series to simulate a typical sloping building roof with photovoltaic installation. In this system the air flows through a channel on the rear side of PV panels. The potential for increasing the heat exchange from the photovoltaic panel to the circulating air by the addition of a thin metal sheet (TMS) in the middle of air channel or metal fins (FIN) along the air duct was examined. The operation of the device was studied with the air duct closed tightly to avoid air circulation (CLOSED) and the air duct open (REF), with the thin metal sheet (TMS) and with metal fins (FIN). In each case the experiments were performed under sunlight and the operating parameters of the experimental device determining the electrical and thermal performance of the system were observed and recorded during a whole day and for several days. We collected the data and form PV panels from the comparative diagrams of the experimental results regarding the temperature of solar cells, the electrical efficiency of the installation, the temperature of the back wall of the air duct and the temperature difference in the entrance and exit of the air duct. The comparative results from the measurements determine the improvement in electrical performance of the photovoltaic cells because of the reduction of their temperature, which is achieved by the naturally circulating air.

Numerical investigation of heat transfer effects in small wave rotor

International Nuclear Information System (INIS)

Deng, Shi; Okamoto, Koji; Teramoto, Susumu

2015-01-01

Although a wave rotor is expected to enhance the performance of the ultra-micro gas turbine, the device itself may be affected by downsizing. Apart from the immediate effect of viscosity on flow dynamics when downscaled, the effects of heat transfer on flow field increase at such small scales. To gain an insight into the effects of heat transfer on the internal flow dynamics, numerical investigations were carried out with adiabatic, isothermal and conjugate heat transfer boundary treatments at the wall, and the results compared and discussed in the present study. With the light shed by the discussion of adiabatic and conjugate heat transfer boundary treatments, this work presents investigations of the heat flux distributions, as well as the effects of heat transfer on the internal flow dynamics and the consequent charging and discharging processes for various sizes. When heat transfer is taken into account, states of fluid in the cell before compression process varies, shock waves in compression process are found to be weaker, and changes in the charging and discharging processes are observed. Heat transfer differences between conjugate heat transfer boundary treatment and isothermal boundary treatment are addressed through comparisons of local wall temperature and heat flux. As a result, the difference in discharging temperature of high pressure fluid is noticeable in all sizes investigated, and the rapid increase of differences between results of isothermal and conjugate heat transfer boundary treatment in small size reveals that for certain small sizes (length of cell < 23 mm) the thermal boundary treatment should be taken care of.

Incoherently Coupled Grey-Grey Spatial Soliton Pairs in Biased Two-Photon Photovoltaic Photorefractive Crystals

International Nuclear Information System (INIS)

Su Yanli; Jiang Qichang; Ji Xuanmang

2010-01-01

The incoherently coupled grey-grey screening-photovoltaic spatial soliton pairs are predicted in biased two-photon photovoltaic photorefractive crystals under steady-state conditions. These grey-grey screening-photovoltaic soliton pairs can be established provided that the incident beams have the same polarization, wavelength, and are mutually incoherent. The grey-grey screening-photovoltaic soliton pairs can be considered as the united form of grey-grey screening soliton pairs and open or closed-circuit grey-grey photovoltaic soliton pairs. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

A new photovoltaic solar-assisted loop heat pipe/heat-pump system%新型光伏-太阳能环形热管/热泵复合系统

Institute of Scientific and Technical Information of China (English)

张龙灿; 裴刚; 张涛; 季杰

2014-01-01

The photovoltaic solar assisted loop heat pipe system/heat-pump (PV-SALHP/HP) is the combination of solar assisted loop heat pipe system (SALHP) and solar assisted heat pipe (SAHP). A photovoltaic/thermal (PVT) evaporator and condenser could be shared by two circling modes, and so is the working medium. The loop heat pipe mode will be utilized when solar radiation is strong and the temperature of working medium in PVT evaporator is higher than that in condenser. Correspondingly, the heat pump mode will be started when solar radiation is weak or the temperature difference of working medium in PVT evaporator and condenser cannot satisfy the condition of loop heat pipe mode. The loop heat pipe mode is passive and the heat pump mode is active, which means that the loop heat pipe mode does not consume work and the heat pump mode does. Therefore, the transformable mode of system could heavily reduce power consumption, raise the utilization ratio of solar energy, and promote energy saving. A PV-SAHP/LHP test rig is built. The instantaneous and daily performance of the loop heat pipe mode and heat pump mode is studied.%光伏-太阳能环形热管/热泵复合系统将太阳能环形热管循环模式和太阳能热泵循环模式有机结合，两者采用相同的工质，共用一个PVT蒸发器和冷凝器。当太阳辐照强度较强，工质在PVT蒸发器中的温度高于冷凝器中的温度时，可以利用环形热管模式制热；当太阳辐照强度较弱或工质在PVT蒸发器中与冷凝器中的温差无法满足环形热管模式运行时，可以利用热泵模式制热。两种模式既能够独立运行，又可以互相切换，确保热能的稳定供应，同时能够明显降低系统耗电量。搭建了光伏-太阳能环形热管/热泵复合系统实验平台，对复合系统在环形热管模式和热泵模式独立运行时的瞬时性能和全天性能进行了实验研究。

Cost and primary energy efficiency of small-scale district heating systems

International Nuclear Information System (INIS)

Truong, Nguyen Le; Gustavsson, Leif

2014-01-01

Highlights: • We analyzed minimum-cost options for small-scale DHSs under different contexts. • District heat production cost increases with reduced DHS scales. • Fewer technical options are suitable for small-scale DHSs. • Systems with combined technologies are less sensitive to changes in fuel prices. - Abstract: Efficient district heat production systems (DHSs) can contribute to achieving environmental targets and energy security for countries that have demands for space and water heating. The optimal options for a DHS vary with the environmental and social-political contexts and the scale of district heat production, which further depends on the size of the community served and the local climatic conditions. In this study, we design a small-scale, minimum-cost DHS that produces approximately 100 GWh heat per year and estimate the yearly production cost and primary energy use of this system. We consider conventional technologies, such as heat-only boilers, electric heat pumps and combined heat and power (CHP) units, as well as emerging technologies, such as biomass-based organic Rankine cycle (BORC) and solar water heating (SWH). We explore how different environmental and social-political situations influence the design of a minimum-cost DHS and consider both proven and potential technologies for small-scale applications. Our calculations are based on the real heat load duration curve for a town in southern Sweden. We find that the district heat production cost increases and that the potential for cogeneration decreases with smaller district heat production systems. Although the selection of technologies for a minimum-cost DHS depends on environmental and social-political contexts, fewer technical options are suitable for small-scale systems. Emerging technologies such as CHP-BORC and SWH improve the efficiency of primary energy use for heat production, but these technologies are more costly than conventional heat-only boilers. However, systems with

A molecular spin-photovoltaic device.

Science.gov (United States)

Sun, Xiangnan; Vélez, Saül; Atxabal, Ainhoa; Bedoya-Pinto, Amilcar; Parui, Subir; Zhu, Xiangwei; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E

2017-08-18

We fabricated a C 60 fullerene-based molecular spin-photovoltaic device that integrates a photovoltaic response with the spin transport across the molecular layer. The photovoltaic response can be modified under the application of a small magnetic field, with a magnetophotovoltage of up to 5% at room temperature. Device functionalities include a magnetic current inverter and the presence of diverging magnetocurrent at certain illumination levels that could be useful for sensing. Completely spin-polarized currents can be created by balancing the external partially spin-polarized injection with the photogenerated carriers. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Effect of heat-insulating wall on input energy of a photovoltaic/solar/air-heat system for a residence; Jutaku no kodannetsuka ni yoru taiyoko netsu/taiki netsu system no donyu energy sakugen koka

Energy Technology Data Exchange (ETDEWEB)

Kenmoku, Y; Sakakibara, T [Toyohashi University of Technology, Aichi (Japan); Nakagawa, S [Maizuru College of Technology, Kyoto (Japan)

1996-10-27

A proposal was made to introduce a photovoltaic/solar/air-heat system which positively utilizes natural energy in order to curtail consumption of fossil energy, corroborating that the system has greatly reduced energy input in the primary energy level in a house. This paper examines the effect of curtailment of energy input in the case of reducing the load of air conditioning through the high heat insulation of a house. The energy input was evaluated by calculating additional equipment energy needed newly for the high heat insulation. The system performance and the energy load varied greatly depending on weather conditions. The subject system consisted of solar cells, inverter, heat concentrator, heat storage tank, heat pump and gas hot-water supply device. The thickening of the insulation sharply reduced heating load in the house, thereby decreasing fuel energy substantially. An insulation material of 100mm thick was capable of reducing energy input by 16-23% compared with that of 50mm thick. 5 refs., 5 figs, 3 tabs.

Wind tunnel study of natural ventilation of building integrated photovoltaics double skin façade

Science.gov (United States)

Hudişteanu, Sebastian Valeriu; Popovici, Cătălin George; Cherecheş, Nelu-Cristian

2018-02-01

The paper presents a wind tunnel experimental analysis of a small-scale building model (1:30). The objective of the study is to determine the wind influence on the ventilation of a double skin façade channel (DSF) and the cooling effect over integrated photovoltaic panels. The tests were achieved by conceiving and implementation of an experimental program using a wind tunnel with atmospheric boundary layer. The effect of the wind over the ventilation of the horizontal channels of double skin façades is evaluated for different incident velocities. The results are generalized for the average steady state values of the velocities analysed. The experimental results put in evidence the correlation between the reference wind velocity and the dynamics of the air movement inside the double skin façade. These values are used to determine the convective heat transfer and the cooling effect of the air streams inside the channel upon the integrated photovoltaic panels. The decrease of the photovoltaic panels temperature determines a raise of 11% in efficiency and power generated.

Wind tunnel study of natural ventilation of building integrated photovoltaics double skin façade

Directory of Open Access Journals (Sweden)

Hudişteanu Sebastian Valeriu

2018-01-01

Full Text Available The paper presents a wind tunnel experimental analysis of a small-scale building model (1:30. The objective of the study is to determine the wind influence on the ventilation of a double skin façade channel (DSF and the cooling effect over integrated photovoltaic panels. The tests were achieved by conceiving and implementation of an experimental program using a wind tunnel with atmospheric boundary layer. The effect of the wind over the ventilation of the horizontal channels of double skin façades is evaluated for different incident velocities. The results are generalized for the average steady state values of the velocities analysed. The experimental results put in evidence the correlation between the reference wind velocity and the dynamics of the air movement inside the double skin façade. These values are used to determine the convective heat transfer and the cooling effect of the air streams inside the channel upon the integrated photovoltaic panels. The decrease of the photovoltaic panels temperature determines a raise of 11% in efficiency and power generated.

Enhanced Light Absorption in Fluorinated Ternary Small-Molecule Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Eastham, Nicholas D. [Department; Dudnik, Alexander S. [Department; Harutyunyan, Boris [Department; Aldrich, Thomas J. [Department; Leonardi, Matthew J. [Department; Manley, Eric F. [Department; Chemical; Butler, Melanie R. [Department; Harschneck, Tobias [Department; Ratner, Mark A. [Department; Chen, Lin X. [Department; Chemical; Bedzyk, Michael J. [Department; Department; Melkonyan, Ferdinand S. [Department; Facchetti, Antonio [Department; Chang, Robert P. H. [Department; Marks, Tobin J. [Department; Department

2017-06-14

Using small-molecule donor (SMD) semiconductors in organic photovoltaics (OPVs) has historically afforded lower power conversion efficiencies (PCEs) than their polymeric counterparts. The PCE difference is attributed to shorter conjugated backbones, resulting in reduced intermolecular interactions. Here, a new pair of SMDs is synthesized based on the diketopyrrolopyrrole-benzodithiophene-diketopyrrolopyrrole (BDT-DPP2) skeleton but having fluorinated and fluorinefree aromatic side-chain substituents. Ternary OPVs having varied ratios of the two SMDs with PC61BM as the acceptor exhibit tunable open-circuit voltages (Vocs) between 0.833 and 0.944 V due to a fluorination-induced shift in energy levels and the electronic “alloy” formed from the miscibility of the two SMDs. A 15% increase in PCE is observed at the optimal ternary SMD ratio, with the short-circuit current density (Jsc) significantly increased to 9.18 mA/cm2. The origin of Jsc enhancement is analyzed via charge generation, transport, and diffuse reflectance measurements, and is attributed to increased optical absorption arising from a maximum in film crystallinity at this SMD ratio, observed by grazing incidence wide-angle X-ray scattering.

Development of small and medium reactors for power and heat production

International Nuclear Information System (INIS)

Becka, J.

1978-01-01

Data are given on the current state of development of small and medium-power reactors designed mainly for electric power production in small power grids, for heat production for small- and medium-power desalination plants with possible electric power generation, for process steam production and heat development for district heating systems, again combined with electric power generation, and for propelling big and fast passenger ships. A diagram is shown of the primary system of an integrated PWR derived from the Otto Hahn reactor. The family is listed of the standard sizes of the integral INTERATOM company pressurized water reactors. Also listed are the specifications and design of CAS 2CG and AS 3G type reactors used mainly for long-distance heating systems. (J.B.)

相变储能光伏太阳能热泵干燥系统的研究%Research on Phase Change Energy Storage Photovoltaic Solar Heat Pump Drying System

Institute of Scientific and Technical Information of China (English)

胡静; 蒋绿林; 侯亚祥; 王昌领; 张亮

2017-01-01

The experimental platform of phase change energy storage photovoltaic solar heat pump drying system is estab-lished in this paper ,it is introduced the way of the system and the matching of photovoltaic solar heating evaporator and dc compressor is calculated and finally the experiment data is analyzed in detail .It is concluded that when the solar radiation amount is 800 W/m2 and photovoltaic solar heating evaporator area is 12 m2 ,heat capacity is 10 kW and solar photovoltaic power generation is 6 .2 kW·h ,in which the photovoltaic power consumption is greater than the compressor ,meeting the op-eration requirements without additional power .The COP of system is 3 .25 .The phase change energy storage can solve run-ning problem of the system ,which is caused by the amount of solar irradiance fluctuation ,and so it has significant energy saving and environmental protection .%建立了相变储能光伏太阳能热泵干燥系统实验平台，介绍了系统的运行方式以及太阳能光伏集热蒸发器与直流压缩机的匹配计算，最后对实验数据进行了分析。结果表明，太阳能辐照量为800 W／m2、光伏集热蒸发器面积为12m2的条件下，系统制热功率为10kW，太阳能光伏集热蒸发器发电量为6．2kW·h，大于直流压缩机的耗电量，满足供电要求；实验所得系统COP为3．25。相变储能可以解决太阳辐照波动导致的系统运行不稳定问题，具有显著的节能性和环保性。

Is the photovoltaic to be saved?

International Nuclear Information System (INIS)

Nifenecker, H.

2011-01-01

This paper first proposes a critical overview of the current financial support given to the photovoltaic energy. He notably criticizes the obligation for EDF to purchase the electricity so produced, and the obtained results in terms of renewable energy production, emission reduction, development of the photovoltaic industry sector, and development of decentralized energy productions. He proposes a better philosophy for the development of solar energy in Europe: to use solar in energy rather in Spain than in northern Europe, to use solar energy for heating rather than for electricity production in France, to develop storage practices, to encourage self-consumption

Transient Model of Hybrid Concentrated Photovoltaic with Thermoelectric Generator

DEFF Research Database (Denmark)

Mahmoudi Nezhad, Sajjad; Qing, Shaowei; Rezaniakolaei, Alireza

2017-01-01

Transient performance of a concentrated photovoltaic thermoelectric (CPV-TEG) hybrid system is modeled and investigated. A heat sink with water, as the working fluid has been implemented as the cold reservoir of the hybrid system to harvest the heat loss from CPV cell and to increase the efficiency...

Solar Process Heat Basics | NREL

Science.gov (United States)

Process Heat Basics Solar Process Heat Basics Commercial and industrial buildings may use the same solar technologies-photovoltaics, passive heating, daylighting, and water heating-that are used for residential buildings. These nonresidential buildings can also use solar energy technologies that would be

Subcooled flow boiling heat transfer from microporous surfaces in a small channel

International Nuclear Information System (INIS)

Yan, Sun; Li, Zhang; Hong, Xu; Xiaocheng, Zhong

2011-01-01

The continuously increasing requirement for high heat transfer rate in a compact space can be met by combining the small channel/microchannel and heat transfer enhancement methods during fluid subcooled flow boiling. In this paper, the sintered microporous coating, as an efficient means of enhancing nucleate boiling, was applied to a horizontal, rectangular small channel. Water flow boiling heat transfer characteristics from the small channel with/without the microporous coating were experimentally investigated. The small channel, even without the coating, presented flow boiling heat transfer enhancement at low vapor quality due to size effects of the channel. This enhancement was also verified by under-predictions from macro-scale correlations. In addition to the enhancement from the channel size, all six microporous coatings with various structural parameters were found to further enhance nucleate boiling significantly. Effects of the coating structural parameters, fluid mass flux and inlet subcooling were also investigated to identify the optimum condition for heat transfer enhancement. Under the optimum condition, the microporous coating could produce the heat transfer coefficients 2.7 times the smooth surface value in subcooled flow boiling and 3 times in saturated flow boiling. The combination of the microporous coating and small channel led to excellent heat transfer performance, and therefore was deemed to have promising application prospects in many areas such as air conditioning, chip cooling, refrigeration systems, and many others involving compact heat exchangers. (authors)

Photovoltaic Self-Consumption; Autoconsumo fotovoltaico

Energy Technology Data Exchange (ETDEWEB)

Alonso Abella, M.; Chenlo Romero, F.

2013-02-01

This paper analyzes the photovoltaic (PV) self consumption, or the option of using photovoltaic systems connected to the electric grid for the purpose of consuming the PV generated energy in the own installation (homes, small industries, office buildings, etc.) in order to reduce the external demand and the electric bill. At this time there is a legal vacuum regarding the installation of these generation systems for self-consumption, and the PV business sector and society are calling for the establishment of a legal and economic framework. Assuming that what can be saved with a photovoltaic system for domestic self-consumption is the cost of the kWh consumed currently 15c/kWh that there are no additional charges and that the cost of the turnkey photovoltaic system currently ranges from 1.8/Wp to 2.5/Wp, the resulting amortization period would be between 8 and 11 years for the condition of annual net metering. (Author) 31 refs.

The future of the photovoltaic market (demand side/supply side)

International Nuclear Information System (INIS)

Zahedi, A.

1998-01-01

At present the main PV application market sectors are communications, leisure, boating, solar home systems, and water pumping. It is predicted that in the future, the largest photovoltaic market segments will be solar home photovoltaic systems, grid-connected small-scale photovoltaic systems, grid-connected medium-to-large scale photovoltaic systems, the communications sector and in the electrification of remote and isolated areas. The main factors favoring photovoltaic technology in remote and isolated areas result from: the high costs of conventional energy sources in remote locations; the loss of a scale-economy effect, which means specific costs of small photovoltaic systems are not much higher than those of larger photovoltaic systems; price of fuel, fuel transportation and spare part supplies. The major factors inhibiting the photovoltaic technology include high initial costs, lack of skilled man power, lack of good quality data and social acceptance. A roof top mounted photovoltaic system is one type of PV system which has attracted lots of interest among the people of north America and Europe. The generation of electricity by this system is attractive because: generation is on-site. This results in reduction of transmission costs and transmission losses; the cost of roofing tiles can be eliminated by using mounted PV systems instead; there is no need for additional land for power generation; visual impacts are limited. The objective of this paper is to review the development of the photovoltaic market in the recent 10 year period and discuss the future markets for this technology with respect to supply and demand

Regional Analysis of Aids and Prices for Small-scale Grid-connected Solar Photovoltaic Systems in Spain

International Nuclear Information System (INIS)

Varela, M.; Ramirez, L.; Mora, L.; Sidrach de Cardona, M.

2002-01-01

Electricity production from small solar photovoltaic systems in Spain obtains a premium pnce of 0,36 ε/kWh over the electricity market price or a fix price of 0,40 ε/kWh. The development of these small systems in Spain clearly demonstrates that the established prime is not sufficient in the majority of locations. On the other hand, the prime revision set up by the RD 2818/98, considering the profitability of the renewable installations, demand a regional analysis of small PV systems profitability necessary in Spain. The accomplished results permit to conclude that the amount of the current prime is by itself insufficient to make profitable the small grid-connected PV systems in anywhere of the national geography. To guarantee the profitability of these systems it should be necessary to place the fix price at around 0,93 ε/kWh. However, if the duplication of the current price obtained by these installations was considered, this could ensure the profitability of these small systems in at least the 77% of the land. (Author) 12 refs

Optimal stochastic coordinated scheduling of proton exchange membrane fuel cell-combined heat and power, wind and photovoltaic units in micro grids considering hydrogen storage

International Nuclear Information System (INIS)

Bornapour, Mosayeb; Hooshmand, Rahmat-Allah; Khodabakhshian, Amin; Parastegari, Moein

2017-01-01

Highlights: •Stochastic model is proposed for coordinated scheduling of renewable energy sources. •The effect of combined heat and power is considered. •Hydrogen storage is considered for fuel cells. •Maximizing profits of micro grid is considered as objective function. •Considering the uncertainties of problem lead to profit increasing. -- Abstract: Nowadays, renewable energy sources and combined heat and power units are extremely used in micro grids, so it is necessary to schedule these units to improve the performance of the system. In this regard, a stochastic model is proposed in this paper to schedule proton exchange membrane fuel cell-combined heat and power, wind turbines, and photovoltaic units coordinately in a micro grid while considering hydrogen storage. Hydrogen storage strategy is considered for the operation of proton exchange membrane fuel cell-combined heat and power units. To consider stochastic generation of renewable energy source units in this paper, a scenario-based method is used. In this method, the uncertainties of electrical market price, the wind speed, and solar irradiance are considered. This stochastic scheduling problem is a mixed integer- nonlinear programming which considers the proposed objective function and variables of coordinated scheduling of PEMFC-CHP, wind turbines and photovoltaic units. It also considers hydrogen storage strategy and converts it to a mixed integer nonlinear problem. In this study a modified firefly algorithm is used to solve the problem. This method is examined on modified 33-bus distributed network as a MG for its performance.

Solar cooling for small office buildings: Comparison of solar thermal and photovoltaic options for two different European climates

Energy Technology Data Exchange (ETDEWEB)

Hartmann, N. [University of Stuttgart, Institute of Energy Economics and the Rational Use of Energy (IER), Hessbruehlstr. 49a, 70565 Stuttgart (Germany); Glueck, C. [Karlsruhe Institute of Technology (KIT), Institute of Fluid Machinery (FSM), Kaiserstr. 12, 76131 Karlsruhe (Germany); Schmidt, F.P. [Karlsruhe Institute of Technology (KIT), Institute of Fluid Machinery (FSM), Kaiserstr. 12, 76131 Karlsruhe (Germany); Fraunhofer ISE, Heidenhofstr. 2, 79110 Freiburg (Germany)

2011-05-15

We present a comparison of solar thermal and solar electric cooling for a typical small office building exposed to two different European climates (Freiburg and Madrid). The investigation is based on load series for heating and cooling obtained previously from annual building simulations in TRNSYS. A conventional compression chiller is used as the reference system against which the solar options are evaluated with respect to primary energy savings and additional cost. A parametric study on collector and storage size is carried out for the solar thermal system to reach achieve the minimal cost per unit of primary energy saved. The simulated solar electric system consists of the reference system, equipped with a grid connected photovoltaic module, which can be varied in size. For cost comparison of the two systems, the electric grid is assumed to function as a cost-free storage. A method to include macroeconomic effects in the comparison is presented and discussed. Within the system parameters and assumptions used here, the grid coupled PV system leads to lower costs of primary energy savings than the solar thermal system at both locations. The presumed macroeconomic advantages of the solar thermal system, due to the non-usage of energy during peak demand, can be confirmed for Madrid. (author)

Copper oxide/N-silicon heterojunction photovoltaic device

Science.gov (United States)

Feng, Tom; Ghosh, Amal K.

1982-01-01

A photovoltaic device having characteristics of a high efficiency solar cell comprising a Cu.sub.x O/n-Si heterojunction. The Cu.sub.x O layer is formed by heating a deposited copper layer in an oxygen containing ambient.

Systematic procedures for sizing photovoltaic pumping system, using water tank storage

International Nuclear Information System (INIS)

Hamidat, A.; Benyoucef, B.

2009-01-01

In this work, the performances of the photovoltaic pumping destined to supply drinking water in remote and scattered small villages have been studied. The methodology adopted proposes various procedures based on the water consumption profiles, total head, tank capacity and photovoltaic array peak power. A method of the load losses probability (LLP) has been used to optimize sizing of the photovoltaic pumping systems with a similarity between the storage energy in batteries and water in tanks. The results were carried out using measured meteorological data for four localities in Algeria: Algiers and Oran in the north, Bechar and Tamanrasset in the south. The results show that the performance of the photovoltaic pumping system depends deeply on the pumping total head and the peak power of the photovoltaic array. Also, for the southern localities, the LLP method shows that the size of the photovoltaic array varies versus LLP on a small scale. On the other hand, for the northern localities, the sizing of the photovoltaic array is situated on a large scale power. Because of the current high crud-oil price, the photovoltaic pumping still to be the best adopted energy resource to supply drinking water in remote and scattered villages

Cost Estimates Of Concentrated Photovoltaic Heat Sink Production

Science.gov (United States)

2016-06-01

PV), return on investment (ROI) 15. NUMBER OF PAGES 59 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY...improvements increase overall system returns on investment and 11 provide pathways for further reduction in system costs (Phillips et al., 2015). Phillips...generation. As the CPV market has matured, production costs have come down to near flat-panel photovoltaic (PV) production costs. CPV units

Performance Evaluation of a Helical Coil Heat Exchanger Working under Supercritical Conditions in a Solar Organic Rankine Cycle Installation

Directory of Open Access Journals (Sweden)

Marija Lazova

2016-06-01

Full Text Available Worldwide interest in low grade heat valorization using organic Rankine cycle (ORC technologies has increased significantly. A new small-scale ORC with a net capacity of 3 kW was efficiently integrated with a concentrated solar power technology for electricity generation. The excess heat source from Photovoltaic (PV collectors with a maximum temperature of 100 °C was utilized through a supercritical heat exchanger that uses R-404A as working medium. By ensuring supercritical heat transfer leads to a better thermal match in the heat exchanger and improved overall cycle efficiency. A helical coil heat exchanger was designed by using heat transfer correlations from the literature. These heat transfer correlations were derived for different conditions than ORCs and their estimated uncertainty is ~20%. In order to account for the heat transfer correlation uncertainties this component was oversized by 20%. Next, a prototype was built and installed in an integrated concentrated photovoltaic/thermal (CPV/T/Rankine system. The results from the measurements show that for better estimation of the sizing of the heat exchanger a more accurate correlation is required in order to design an optimal configuration and thus employ cheaper components.

Stand-alone photovoltaic (PV) integrated with earth to air heat exchanger (EAHE) for space heating/cooling of adobe house in New Delhi (India)

International Nuclear Information System (INIS)

Chel, Arvind; Tiwari, G.N.

2010-01-01

This paper deals with an experimental outdoor annual performance evaluation of 2.32 kW P photovoltaic (PV) power system located at solar energy park in New Delhi composite climatic conditions. This PV system operates the daily electrical load nearly 10 kW h/day which comprises of various applications such as electric air blower of an earth to air heat exchanger (EAHE) used for heating/cooling of adobe house, ceiling fan, fluorescent tube-light, computer, submersible water pump, etc. The outdoor efficiencies, power generated and lost in PV system components were determined using hourly experimental measured data for 1 year on typical clear day in each month. These realistic data are useful for design engineers for outdoor assessment of PV system components. The energy conservation, mitigation of CO 2 emission and carbon credit potential of the existing PV integrated EAHE system is presented in this paper. Also, the energy payback time (EPBT) and unit cost of electricity were determined for both stand-alone PV (SAPV) and building roof integrated PV (BIPV) systems.

Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking

OpenAIRE

Basil M Hamed; Mohammed S. El-Moghany

2012-01-01

The cell has optimum operating point to be able to get maximum power. To obtain Maximum Power from photovoltaic array, photovoltaic power system usually requires Maximum Power Point Tracking (MPPT) controller. This paper provides a small power photovoltaic control system based on fuzzy control with FPGA technology design and implementation for MPPT. The system composed of photovoltaic module, buck converter and the fuzzy logic controller implemented on FPGA for controlling on/off time of MOSF...

Spatial solitons in biased photovoltaic photorefractive materials with the pyroelectric effect

Energy Technology Data Exchange (ETDEWEB)

Katti, Aavishkar; Yadav, R.A., E-mail: rayadav@bhu.ac.in

2017-01-23

Spatial solitons in biased photorefractive media due to the photovoltaic effect and the pyroelectric effect are investigated. The pyroelectric field considered is induced due to the heating by the incident beam's energy. These solitons can be called screening photovoltaic pyroelectric solitons. It is shown that the solitons can exist in the bright and dark realizations. The conditions for formation of these solitons are discussed. Relevant example is considered to illustrate the self trapping of such solitons. The external electric field interacts with the photovoltaic field and the pyroelectric field to either support or oppose the self trapping. - Highlights: • Effect of pyroelectric field on screening photovoltaic solitons is studied. • Illumination induced pyroelectric field is considered for the first time. • Self trapping depends on external, pyroelectric and photovoltaic space charge field.

Solar energy – new photovoltaic technologies

DEFF Research Database (Denmark)

Sommer-Larsen, Peter

2009-01-01

Solar energy technologies directly convert sunlight into electricity and heat, or power chemical reactions that convert simple molecules into synthetic chemicals and fuels. The sun is by far the most abundant source of energy, and a sustainable society will need to rely on solar energy as one...... of its major energy sources. Solar energy is a focus point in many strategies for a sustainable energy supply. The European Commission’s Strategic Energy Plan (SET-plan) envisages a Solar Europe Initiative, where photovoltaics and concentrated solar power (CSP) supply as much power as wind mills...... in the future. Much focus is directed towards photovoltaics presently. Installation of solar cell occurs at an unprecedented pace and the expectations of the photovoltaics industry are high: a total PV capacity of 40 GW by 2012 as reported by a recent study. The talk progresses from general solar energy topics...

Numerical and Experimental Study on Energy Performance of Photovoltaic-Heat Pipe Solar Collector in Northern China

Directory of Open Access Journals (Sweden)

Hongbing Chen

2015-01-01

Full Text Available Several studies have found that the decrease of photovoltaic (PV cell temperature would increase the solar-to-electricity conversion efficiency. Water type PV/thermal (PV/T system was a good choice but it could become freezing in cold areas of Northern China. This paper proposed a simple combination of common-used PV panel and heat pipe, called PV-heat pipe (PV-HP solar collector, for both electrical and thermal energy generation. A simplified one-dimensional steady state model was developed to study the electrical and thermal performance of the PV-HP solar collector under different solar radiations, water flow rates, and water temperatures at the inlet of manifold. A testing rig was conducted to verify the model and the testing data matched very well with the simulation values. The results indicated that the thermal efficiency could be minus in the afternoon. The thermal and electrical efficiencies decreased linearly as the inlet water temperature and water flow rate increased. The thermal efficiency increased while the electrical efficiency decreased linearly as the solar radiation increased.

Fire-induced reradiation underneath photovoltaic arrays on flat roofs

DEFF Research Database (Denmark)

Kristensen, Jens Steemann; Merci, Bart; Jomaas, Grunde

2018-01-01

The impact of the reflection of fire-induced heat from a gas burner was studied experimentally to gain knowledge on the interaction between photovoltaic (PV) panels and a fire on flat roofs. The heat flux was measured in a total of eight points at the same level as the top of the gas burner. The ...

Performance Analysis of a Photovoltaic-Thermal Integrated System

International Nuclear Information System (INIS)

Radziemska, E.

2009-01-01

The present commercial photovoltaic solar cells (PV) converts solar energy into electricity with a relatively low efficiency, less than 20%. More than 80% of the absorbed solar energy is dumped to the surroundings again after photovoltaic conversion. Hybrid PV/T systems consist of PV modules coupled with the heat extraction devices. The PV/T collectors generate electric power and heat simultaneously. Stabilizing temperature of photovoltaic modules at low level is highly desirable to obtain efficiency increase. The total efficiency of 60-80% can be achieved with the whole PV/T system provided that the T system is operated near ambient temperature. The value of the low-T heat energy is typically much smaller than the value of the PV electricity. The PV/T systems can exist in many designs, but the most common models are with the use of water or air as a working fuid. Efficiency is the most valuable parameter for the economic analysis. It has substantial meaning in the case of installations with great nominal power, as air-cooled Building Integrated Photovoltaic Systems (BIPV). In this paper the performance analysis of a hybrid PV/T system is presented: an energetic analysis as well as an exergetic analysis. Exergy is always destroyed when a process involves a temperature change. This destruction is proportional to the entropy increase of the system together with its surroundings the destroyed exergy has been called energy. Exergy analysis identifies the location, the magnitude, and the sources of thermodynamic inefficiencies in a system. This information, which cannot be provided by other means (e.g., an energy analysis), is very useful for the improvement and cost-effectiveness of the system. Calculations were carried out for the tested water-cooled ASE-100-DGL-SM Solar watt module.

Performance Analysis of a Photovoltaic-Thermal Integrated System

Directory of Open Access Journals (Sweden)

Ewa Radziemska

2009-01-01

Full Text Available The present commercial photovoltaic solar cells (PV converts solar energy into electricity with a relatively low efficiency, less than 20%. More than 80% of the absorbed solar energy is dumped to the surroundings again after photovoltaic conversion. Hybrid PV/T systems consist of PV modules coupled with the heat extraction devices. The PV/T collectors generate electric power and heat simultaneously. Stabilizing temperature of photovoltaic modules at low level is higly desirable to obtain efficiency increase. The total efficiency of 60–80% can be achieved with the whole PV/T system provided that the T system is operated near ambient temperature. The value of the low-T heat energy is typically much smaller than the value of the PV electricity. The PV/T systems can exist in many designs, but the most common models are with the use of water or air as a working fuid. Efficiency is the most valuable parameter for the economic analysis. It has substantial meaning in the case of installations with great nominal power, as air-cooled Building Integrated Photovoltaic Systems (BIPV. In this paper the performance analysis of a hybrid PV/T system is presented: an energetic analysis as well as an exergetic analysis. Exergy is always destroyed when a process involves a temperature change. This destruction is proportional to the entropy increase of the system together with its surroundings—the destroyed exergy has been called anergy. Exergy analysis identifies the location, the magnitude, and the sources of thermodynamic inefficiences in a system. This information, which cannot be provided by other means (e.g., an energy analysis, is very useful for the improvement and cost-effictiveness of the system. Calculations were carried out for the tested water-cooled ASE-100-DGL-SM Solarwatt module.

Photovoltaic power generation system with photovoltaic cells as bypass diodes

Science.gov (United States)

Lentine, Anthony L.; Nielson, Gregory N.; Tauke-Pedretti, Anna; Cruz-Campa, Jose Luis; Okandan, Murat

2017-11-28

A photovoltaic power generation system that includes a solar panel is described herein. The solar panel includes a photovoltaic sub-module, which includes a group of microsystem enabled photovoltaic cells. The group includes a first string of photovoltaic cells, a second string of photovoltaic cells, and a differing photovoltaic cell. Photovoltaic cells in the first string are electrically connected in series, and photovoltaic cells in the second string are electrically connected in series. Further, the first string of photovoltaic cells, the second string of photovoltaic cells, and the differing photovoltaic cell are electrically connected in parallel. Moreover, the differing photovoltaic cell is used as a bypass diode for the first string of photovoltaic cells and the second string of photovoltaic cells.

Feasibility and parametric evaluation of hybrid concentrated photovoltaic-thermoelectric system

DEFF Research Database (Denmark)

Rezaniakolaei, Alireza; Rosendahl, Lasse Aistrup

2017-01-01

Concentrated photovoltaic (CPV) system integrated with thermoelectric generators (TEGs) is a novel technology that has potential to offer high efficient system. In this study, a thermally coupled model of concentrated photovoltaic-thermoelctric (CPV/TEG) system is established to investigate...... than CPV-only system. The results indicate that contribution of the TEG in power generation enhances at high sun concentrations. Depending to critical design parameters of the CPV and the TEG, there are optimal values for heat transfer coefficient in the heat sink that offer minimum energy cost....... feasibility of the hybrid system over wide range of solar concentrations and different types of heat sinks. The model takes into account critical design parameters in the CPV and the TEG module. The results of this study show that for thermoelectric materials with ZT ≈ 1, the CPV/TEG system is more efficient...

Standard Specification for Physical Characteristics of Nonconcentrator Terrestrial Photovoltaic Reference Cells

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This specification describes the physical requirements for primary and secondary terrestrial nonconcentrator photovoltaic reference cells. A reference cell is defined as a device that meets the requirements of this specification and is calibrated in accordance with Test Method E1125 or Test Method E1362. 1.2 Reference cells are used in the determination of the electrical performance of photovoltaic devices, as stated in Test Methods E948 and E1036. 1.3 Two reference cell physical specifications are described: 1.3.1 Small-Cell Package Design—A small, durable package with a low thermal mass, wide optical field-of-view, and standardized dimensions intended for photovoltaic devices up to 20 by 20 mm, and 1.3.2 Module-Package Design—A package intended to simulate the optical and thermal properties of a photovoltaic module design, but electric connections are made to only one photovoltaic cell in order to eliminate problems with calibrating series and parallel connections of cells. Physical dimensions ...

Optoelectronic insights into the photovoltaic losses from photocurrent, voltage, and energy perspectives

Science.gov (United States)

Shang, Aixue; An, Yidan; Ma, Dong; Li, Xiaofeng

2017-08-01

Photocurrent and voltage losses are the fundamental limitations for improving the efficiency of photovoltaic devices. It is indeed that a comprehensive and quantitative differentiation of the performance degradation in solar cells will promote the understanding of photovoltaic physics as well as provide a useful guidance to design highly-efficient and cost-effective solar cells. Based on optoelectronic simulation that addresses electromagnetic and carrier-transport responses in a coupled finite-element method, we report a detailed quantitative analysis of photocurrent and voltage losses in solar cells. We not only concentrate on the wavelength-dependent photocurrent loss, but also quantify the variations of photocurrent and operating voltage under different forward electrical biases. Further, the device output power and power losses due to carrier recombination, thermalization, Joule heat, and Peltier heat are studied through the optoelectronic simulation. The deep insight into the gains and losses of the photocurrent, voltage, and energy will contribute to the accurate clarifications of the performance degradation of photovoltaic devices, enabling a better control of the photovoltaic behaviors for high performance.

Comparative analysis of heat pump and biomass boiler for small detached house heating

Directory of Open Access Journals (Sweden)

Olkowski Tomasz

2017-01-01

Full Text Available The purpose of the work is to answer the question - which of the two selected heat sources is more economically beneficial for small detached house: heat pump or biomass boiler fuelled with wood-pellets? The comparative analysis of these sources was carried out to discuss the issue. First, cost of both, equipment and operation of selected heat systems were analysed. Additionally, CO2 emission levels associated with these heat systems were determined. The comparative analysis of the costs of both considered heat systems showed that equipment cost of heat pump system is considerably bigger than the cost of biomass boiler system. The comparison of annual operation costs showed that heat pump operation cost is slightly lower than operation cost of biomass boiler. The analysis of above results shows that lower operation cost of heat pump in comparison with biomass boiler cost lets qualify heat pump as more economically justified only after 38 years of work. For both analysed devices, CO2 emission levels were determined. The considerations take into account the fact that heat pump consumes electricity. It is mostly generated through combustion of coal in Poland. The results show that in Poland biomass boiler can be described as not only more economically justified system but also as considerably more ecological.

Comparative analysis of heat pump and biomass boiler for small detached house heating

Science.gov (United States)

Olkowski, Tomasz; Lipiński, Seweryn; Olędzka, Aneta

2017-10-01

The purpose of the work is to answer the question - which of the two selected heat sources is more economically beneficial for small detached house: heat pump or biomass boiler fuelled with wood-pellets? The comparative analysis of these sources was carried out to discuss the issue. First, cost of both, equipment and operation of selected heat systems were analysed. Additionally, CO2 emission levels associated with these heat systems were determined. The comparative analysis of the costs of both considered heat systems showed that equipment cost of heat pump system is considerably bigger than the cost of biomass boiler system. The comparison of annual operation costs showed that heat pump operation cost is slightly lower than operation cost of biomass boiler. The analysis of above results shows that lower operation cost of heat pump in comparison with biomass boiler cost lets qualify heat pump as more economically justified only after 38 years of work. For both analysed devices, CO2 emission levels were determined. The considerations take into account the fact that heat pump consumes electricity. It is mostly generated through combustion of coal in Poland. The results show that in Poland biomass boiler can be described as not only more economically justified system but also as considerably more ecological.

Solution Processed Organic Photovoltaic Cells Using D-A-D-A-D Type Small Molecular Donor Materials with Benzodithiophene and Diketopyrrolopyrrole Units.

Science.gov (United States)

Park, Sangman; Nam, So Yeon; Suh, Dong Hack; Lee, Jaemin; Lee, Changjin; Yoon, Sung Cheol

2016-03-01

Organic photovoltaic Cells (OPVs) have been considered to be a next-generation energy source to overcome exhaustion of resources. Currently, OPVs are developed based on two types of donor material with polymer and small molecule. Polymeric donor materials have shown better power conversion efficiency (PCE) than small molecular donor materials, since it's easy to control the morphology of photoactive film. However, the difficulty in synthetic reproducibility and purification of polymeric donor were main drawback to overcome. And then, recently small molecule donor materials have been overcome bad morphology of OPVs film by using appropriate alkyl substituents and relatively long conjugation system. In this study, we designed and synthesized D-A-D-A-D type small molecular donor materials containing alternatively linked benzodithiophene (BDT) and diketopyrrolopyrrole (DPP) units. Also, we studied on the effect of photovoltaic performance of prepared small molecular D-A-D-A-D type donor with variation of thiophene links and with/without hexyl substituent. Our small molecular donors showed HOMO energy levels from -5.26 to -5.34 eV and optical bandgaps from 1.70 to 1.87 eV by CV (cyclic voltammetry) and UV/Vis spectroscopy, respectively. Finally, 3.4% of PCE can be obtained using a mixture of BDT(DPP)2-T2 and PCBM as an active layer with a Voc of 0.78 V, a Jsc of 9.72 mA/cm2, and a fill factor of 0.44 under 100 mW/cm2 AM 1.5G simulated light. We will discuss the performance of D-A-D-A-D type small molecular donor based OPVs with variation of both terminal substituents.

Photovoltaic module and interlocked stack of photovoltaic modules

Science.gov (United States)

Wares, Brian S.

2014-09-02

One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

Characterization and Monitoring of a Self-Constructible Photovoltaic-Based Refrigerator

Directory of Open Access Journals (Sweden)

Claudio Del Pero

2016-09-01

Full Text Available At present, in the developing countries, the power grids do not reach every small town and, even when they do, they are not reliable. For this reason, preservation of food and medicines is a sensitive issue for a large number of people. This work introduces the characterization of a new, self-constructible refrigerator, powered by photovoltaic (PV energy, suitable for the preservation of food in rural villages, with a specific focus on Africa’s tropical-equatorial belt. A thermally-insulated envelope, equipped with thermal energy storage, has been designed to be built on-site, by using local materials, and assembled with technical components (direct current (DC compressor, heat exchangers, photovoltaic module. The monitoring activity presented in this work was carried out on a first prototype of the system and enabled the validation of numerical simulations, aimed at assessing its appropriate operability under laboratory conditions. In particular, the work demonstrates that the basic module of the refrigerator, with a net capacity of 250 L and an ice storage of 12.5 kg, is able to maintain an internal temperature below 10 °C also in critical boundary conditions.

Performance Analysis of Photovoltaic Panels with Earth Water Heat Exchanger Cooling

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Jakhar Sanjeev

2016-01-01

Full Text Available The operating temperature is an important factor affecting the performance and life span of the Photovoltaic (PV panels. The rising temperature can be maintained within certain limit using proper cooling techniques. In the present research a novel system for cooling of PV panels named as Earth Water Heat Exchanger (EWHE is proposed and modelled in transient analysis simulation tool (TRNSYS v17.0 for the conditions of Pilani, Rajasthan (India.The various parameters which include cell temperature, PV power output and cell efficiency are observed with respect to variation in mass flow rate of fluid. Simulation results of the system without cooling show that the maximum PV panel temperature reached up to 79.31 °C with electrical efficiency dropped to 9% during peak sunshine hour. On the other hand, when PV panels are coupled with EWHE system, the panel temperature drops to 46.29 °C with an efficiency improving to 11% for a mass flow rate of 0.022 kg/s. In the end the cooling potential of EWHE is found to be in direct correlation with mass flow rate. The proposed system is very useful for the arid regions of western India which are blessed with high solar insolation throughout the year.

Cost of electricity from small scale co-generation of electricity and heat

Energy Technology Data Exchange (ETDEWEB)

Kjellstroem, Bjoern

2012-07-15

There is an increasing interest in Sweden for using also small heat loads for cogeneration of electricity and heat. Increased use of small CHP-plants with heat supply capacities from a few 100 kW(h) up to 10 MW(h) cannot change the structure of the electricity supply system significantly, but could give an important contribution of 2 - 6 TWh(e) annually. The objective of this study was to clarify under what conditions electricity can be generated in small wood fired CHP-plants in Sweden at costs that can compete with those for plants using fossil fuels or nuclear energy. The capacity range studied was 2 - 10 MW(h). The results should facilitate decisions about the meaningfulness of considering CHP as an option when new heat supply systems for small communities or sawmills are planned. At the price for green certificates in Sweden, 250 - 300 SEK/MWh(e), generation costs in small wood fired CHP-plants should be below about 775 SEK/MWh(e) to compete with new nuclear power plants and below about 925 SEK/MWh(e) to compete with generation using fossil fuels.

Joint energy demand and thermal comfort optimization in photovoltaic-equipped interconnected microgrids

International Nuclear Information System (INIS)

Baldi, Simone; Karagevrekis, Athanasios; Michailidis, Iakovos T.; Kosmatopoulos, Elias B.

2015-01-01

Highlights: • Energy efficient operation of photovoltaic-equipped interconnected microgrids. • Optimized energy demand for a block of heterogeneous buildings with different sizes. • Multiobjective optimization: matching demand and supply taking into account thermal comfort. • Intelligent control mechanism for heating, ventilating, and air conditioning units. • Optimization of energy consumption and thermal comfort at the aggregate microgrid level. - Abstract: Electrical smart microgrids equipped with small-scale renewable-energy generation systems are emerging progressively as an alternative or an enhancement to the central electrical grid: due to the intermittent nature of the renewable energy sources, appropriate algorithms are required to integrate these two typologies of grids and, in particular, to perform efficiently dynamic energy demand and distributed generation management, while guaranteeing satisfactory thermal comfort for the occupants. This paper presents a novel control algorithm for joint energy demand and thermal comfort optimization in photovoltaic-equipped interconnected microgrids. Energy demand shaping is achieved via an intelligent control mechanism for heating, ventilating, and air conditioning units. The intelligent control mechanism takes into account the available solar energy, the building dynamics and the thermal comfort of the buildings’ occupants. The control design is accomplished in a simulation-based fashion using an energy simulation model, developed in EnergyPlus, of an interconnected microgrid. Rather than focusing only on how each building behaves individually, the optimization algorithm employs a central controller that allows interaction among the buildings of the microgrid. The control objective is to optimize the aggregate microgrid performance. Simulation results demonstrate that the optimization algorithm efficiently integrates the microgrid with the photovoltaic system that provides free electric energy: in

Simulation of an active cooling system for photovoltaic modules

International Nuclear Information System (INIS)

Abdelhakim, Lotfi

2016-01-01

Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

Simulation of an active cooling system for photovoltaic modules

Energy Technology Data Exchange (ETDEWEB)

Abdelhakim, Lotfi [Széchenyi István University of Applied Sciences, Department of Mathematics, P.O.Box 701, H-9007 Győr (Hungary)

2016-06-08

Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

Design method for photovoltaics-battery storage systems under tropical conditions

Energy Technology Data Exchange (ETDEWEB)

Salem, A I.E.; Bassyouni, A H; Al-Motawakel, M K

1989-01-01

A very limited number of the available design methods can be used with confidence in sizing and costing the stand-alone photovoltaic-battery storage systems operating under the weather conditions of the tropical countries located between 0 and 30/sup 0/N. For this reason we investigated the performance and economics of various photovoltaic-battery storage system configurations. The aim was to prepare a number of sizing and costing design diagrams which detail the effect of climatic, social, and economics parameters on the choice of the stand-alone photovoltaic-battery storage systems. Our strategy was to guide designers, particularly those trying to utilize the stand-alone photovoltaic-battery storage systems in Sana'a (15/sup 0/N) and Cairo (30/sup 0/N), to the logic for selecting a system that physically and economically matches the site potential and the user's electrical needs. Considered here are the relatively small stand-alone photovoltaic-battery storage systems that can be purchased by individuals or commercial and governmental firms to supply all or part of the electrical needs consumed in residence, farms, remote rural communities, or small factories.

Thermoelectric cooling in combination with photovoltaics and thermal energy storage

Directory of Open Access Journals (Sweden)

Skovajsa Jan

2017-01-01

Full Text Available The article deals with the use of modern technologies that can improve the thermal comfort in buildings. The article describes the usage of thermal energy storage device based on the phase change material (PCM. The technology improves the thermal capacity of the building and it is possible to use it for active heating and cooling. It is designed as a “green technology” so it is able to use renewable energy sources, e.g., photovoltaic panels, solar thermal collectors, and heat pump. Moreover, an interesting possibility is the ability to use thermal energy storage in combination with a photovoltaic system and thermoelectric coolers. In the research, there were made measurements of the different operating modes and the results are presented in the text.

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.

Structural and chemical transformations in SnS thin films used in chemically deposited photovoltaic cells

International Nuclear Information System (INIS)

Avellaneda, David; Delgado, Guadalupe; Nair, M.T.S.; Nair, P.K.

2007-01-01

Chemically deposited SnS thin films possess p-type electrical conductivity. We report a photovoltaic structure: SnO 2 :F-CdS-SnS-(CuS)-silver print, with V oc > 300 mV and J sc up to 5 mA/cm 2 under 850 W/m 2 tungsten halogen illumination. Here, SnO 2 :F is a commercial spray-CVD (Pilkington TEC-8) coating, and the rest deposited from different chemical baths: CdS (80 nm) at 333 K, SnS (450 nm) and CuS (80 nm) at 293-303 K. The structure may be heated in nitrogen at 573 K, before applying the silver print. The photovoltaic behavior of the structure varies with heating: V oc ∼ 400 mV and J sc 2 , when heated at 423 K in air, but V oc decreases and J sc increases when heated at higher temperatures. These photovoltaic structures have been found to be stable over a period extending over one year by now. The overall cost of materials, simplicity of the deposition process, and possibility of easily varying the parameters to improve the cell characteristics inspire further work. Here we report two different baths for the deposition of SnS thin films of about 500 nm by chemical deposition. There is a considerable difference in the nature of growth, crystalline structure and chemical stability of these films under air-heating at 623-823 K or while heating SnS-CuS layers, evidenced in XRF and grazing incidence angle XRD studies. Heating of SnS-CuS films results in the formation of SnS-Cu x SnS y . 'All-chemically deposited photovoltaic structures' involving these materials are presented

Combined heat and power solar system

International Nuclear Information System (INIS)

Anon

2000-01-01

An Australian-designed photovoltaic (PV) power system that also supplies hot water is close to commercial release. PVs have been around for decades and solar concentrators have been efficiently heating water for nearly a century. The Australian National University, Department of Engineering - Centre for Sustainable Energy systems (CSES), has designed a domestic scale modular system that not only generates electricity but also provides concentrated thermal energy to heat water for a Solahart hot water system and is designed to be deployed into small to medium scale applications such as hospitals, schools and dwellings with an easily assembled galvanised steel frame. A market research was carried out and is envisaged that at least 7,500 units will be installed annually by the year 2005 and up to 25,000 units by 2008

Photovoltaic for the Chinese; Du photovoltaique pour les Chinois

Energy Technology Data Exchange (ETDEWEB)

Bahjejian, L.

2010-10-15

China produces and exports about half of the photovoltaic cells made in the world. About 1000 Chinese enterprises work in the photovoltaic sector and the offer grows too fast to allow some enterprises to cope with lower and lower production costs. Research activities are a key element for the reduction of production costs but small companies can not usually sustain sufficient research. Economists foresee a strong reorganization of the sector: some enterprises will cease their photovoltaic activities, others will face financial difficulties, others will merge to make bigger companies. To make the demand bigger Chinese authorities are taking steps to develop the photovoltaic home market. The installed capacity of photovoltaic plants in China is expected to be somewhere between 11 GWc and 18 GWc in 2015, figures to be compared with only 0.9 GWc in 2010. (A.C.)

Small-scale heat detection using catalytic microengines irradiated by laser

Science.gov (United States)

Liu, Zhaoqian; Li, Jinxing; Wang, Jiao; Huang, Gaoshan; Liu, Ran; Mei, Yongfeng

2013-01-01

We demonstrate a novel approach to modulating the motion speed of catalytic microtubular engines via laser irradiation/heating with regard to small-scale heat detection. Laser irradiation on the engines leads to a thermal heating effect and thus enhances the engine speed. During a laser on/off period, the motion behaviour of a microengine can be repeatable and reversible, demonstrating a regulation of motion speeds triggered by laser illumination. Also, the engine velocity exhibits a linear dependence on laser power in various fuel concentrations, which implies an application potential as local heat sensors. Our work may hold great promise in applications such as lab on a chip, micro/nano factories, and environmental detection.We demonstrate a novel approach to modulating the motion speed of catalytic microtubular engines via laser irradiation/heating with regard to small-scale heat detection. Laser irradiation on the engines leads to a thermal heating effect and thus enhances the engine speed. During a laser on/off period, the motion behaviour of a microengine can be repeatable and reversible, demonstrating a regulation of motion speeds triggered by laser illumination. Also, the engine velocity exhibits a linear dependence on laser power in various fuel concentrations, which implies an application potential as local heat sensors. Our work may hold great promise in applications such as lab on a chip, micro/nano factories, and environmental detection. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr32494f

Peltier heat of a small polaron in a magnetic semiconductor

International Nuclear Information System (INIS)

Liu, N.H.; Emin, D.

1985-01-01

For the first time the heat transported with a small polaron in both antiferromagnetic and ferromagnetic semiconductors is calculated. This heat, the Peltier heat, π, is obtained from the change of the entropy of the total system upon introduction of a charge carrier. We explicitly consider both the intrasite and intersite exchange interactions between a small polaron and the interacting spins of a spin-1/2 magnet. There are two competing magnetic contributions to the Peltier heat. First, adding the carrier increases the spin entropy of the system. This provides a positive contribution to π. Second, the exchange between the carrier and the sites about it enhances the exchange binding between these sites. This reduces the energetically allowable spin configurations and provides a negative contribution to π. At extremely high temperatures when kT exceeds the intrasite exchange energy, the first effect dominates. Then π is simply augmented by kT ln 2. However, well below the magnetic transition temperature the second effect dominates. In the experimentally accessible range between these limits both effects are comparable and sizable. The net magnetic contribution to the Peltier heat rises with temperature. Thus, a carrier's interactions with its magnetic environment produces a significant and distinctive contribution to its Peltier heat

Peltier heat of a small polaron in a magnetic semiconductor

International Nuclear Information System (INIS)

Liu, N.L.H.; Emin, D.

1984-01-01

The heat transported with a small polaron in both antiferromagnetic and ferromagnetic semiconductors is calculated. This heat, the Peltier heat, π, is obtained from the change of the entropy of the total system upon introduction of a charge carrier. We explicitly consider both the intrasite and intersite exchange interactions between a small polaron and the interacting spins of a spin-1/2 magnet. There are two competing magnetic contributions to the Peltier heat. First, adding the carrier increases the spin entropy of the system. This provides a positive contribution to π. Second, the exchange between the carrier and the sites about it enhances the exchange binding between these sites. This reduces the energetically allowable spin configurations and provides a negative contribution to π. At extremely high temperature when kT exceeds the intrasite exchange energy, the first effect dominates. Then π is simply augmented by kTln2. However, well below the magnetic transition temperature the second effect dominates. In the experimentally accessible range between these limits both effects are comparable and sizable. The net magnetic contribution to the Peltier heat rises with temperature. Thus, a carrier's interactions with its magnetic environment produces a significant and distinctive contribution to its Peltier heat

Ultrathin TaOx film based photovoltaic device

International Nuclear Information System (INIS)

Tyagi, Pawan

2011-01-01

Application of the economical metal oxide thin-film photovoltaic devices is hindered by the poor energy efficiency. This paper investigates the photovoltaic effect with an ultrathin tantalum oxide (TaOx) tunnel barrier, formed by the plasma oxidation of a pre-deposited tantalum (Ta) film. These ∼ 3 nm TaOx tunnel barriers showed approximately 160 mV open circuit voltage and 3-5% energy efficiency, for varying light intensity. The ultrathin TaOx (∼ 3 nm) could absorb approximately 12% of the incident light radiation in 400-1000 nm wavelength range; this strong light absorbing capability was found to be associated with the dramatically large extinction coefficient. Spectroscopic ellipsometry revealed that the extinction coefficient of 3 nm TaOx was ∼ 0.2, two orders higher than that of tantalum penta oxide (Ta 2 O 5 ). Interestingly, refractive index of this 3 nm thick TaOx was comparable with that of stochiometeric Ta 2 O 5 . However, heating and prolonged high-intensity light exposure deteriorated the photovoltaic effect in TaOx junctions. This study provides the basis to explore the photovoltaic effect in a highly economical and easily processable ultrathin metal oxide tunnel barrier or analogous systems.

Photovoltaic-thermal (PV/T) solar collectors: Features and performance modelling

International Nuclear Information System (INIS)

Atienza-Márquez, Antonio; Bruno, Joan Carles; Coronas, Alberto; Korolija, Ivan; Greenough, Richard; Wright, Andy

2017-01-01

Currently, the electrical efficiency of photovoltaic (PV) solar cells ranges between 5–25%. One of the most important parameters that affects the electrical efficiency of a PV collector is the temperature of its cells: the higher temperature, the lower is the efficiency. Photovoltaic/thermal (PV/T) technology is a potential solution to ensure an acceptable solar energy conversion. The PV/T technology produces both electrical and thermal energy simultaneously. It is suitable for low temperature applications (25–40 o C) and overall efficiency increases compared to individual collectors. This paper describes an installation in a single-family house where PV/T collectors are coupled with a ground heat exchanger and a heat pump for domestic hot water and space heating purposes. The aim of this work is twofold. First, the features of the PV/T technology are analyzed. Second, a model of a flat-plate PV/T water collector was developed in TRNSYS in order to analyze collectors performance. (author)

Photovoltaic Reliability Group activities in USA and Brazil (Presentation Recording)

Science.gov (United States)

Dhere, Neelkanth G.; Cruz, Leila R. O.

2015-09-01

Recently prices of photovoltaic (PV) systems have been reduced considerably and may continue to be reduced making them attractive. If these systems provide electricity over the stipulated warranty period, it would be possible attain socket parity within the next few years. Current photovoltaic module qualifications tests help in minimizing infant mortality but do not guarantee useful lifetime over the warranty period. The PV Module Quality Assurance Task Force (PVQAT) is trying to formulate accelerated tests that will be useful towards achieving the ultimate goal of assuring useful lifetime over the warranty period as well as to assure manufacturing quality. Unfortunately, assuring the manufacturing quality may require 24/7 presence. Alternatively, collecting data on the performance of fielded systems would assist in assuring manufacturing quality. Here PV systems installed by home-owners and small businesses can constitute as an important untapped source of data. The volunteer group, PV - Reliable, Safe and Sustainable Quality! (PVRessQ!) is providing valuable service to small PV system owners. Photovoltaic Reliability Group (PVRG) is initiating activities in USA and Brazil to assist home owners and small businesses in monitoring photovoltaic (PV) module performance and enforcing warranty. It will work in collaboration with small PV system owners, consumer protection agencies. Brazil is endowed with excellent solar irradiance making it attractive for installation of PV systems. Participating owners of small PV systems would instruct inverter manufacturers to copy the daily e-mails to PVRG and as necessary, will authorize the PVRG to carry out review of PV systems. The presentation will consist of overall activities of PVRG in USA and Brazil.

Effects of Non-equilibrium Solidification on the Material Properties of Brick Silicon for Photovoltaics

Science.gov (United States)

Regnault, W. F.; Yoo, K. C.; Soltani, P. K.; Johnson, S. M.

1984-01-01

Silicon ingot growth technologies like the Ubiquitous Crystallization Process (UCP) are solidified within a shaping crucible. The rate at which heat can be lost from this crucible minus the rate at which heat is input from an external source determines the rate at which crystallization will occur. Occasionally, when the process parameters for solidification are exceeded, the normally large multi-centimeter grain size material assocated with the UCP will break down into regions containing extremely small, millimeter or less, grain size material. Accompanying this breakdown in grain growth is the development of so called sinuous grain boundaries. The breakdown in grain growth which results in this type of small grain structure with sinuous boundaries is usually associated with the rapid crystallization that would accompany a system failure. This suggests that there are limits to the growth velocity that one can obtain and still expect to produce material that would possess good photovoltaic properties. It is the purpose to determine the causes behind the breakdown of this material and what parameters will determine the best rates of solidification.

Cold local heating. Agrothermal heat supply of an ecovillage; Kalt Nahwaerme. Agrothermische Waermeversorgung einer Plusenergiesiedlung

Energy Technology Data Exchange (ETDEWEB)

Pietruschka, Dirk [Hochschule fuer Technik Stuttgart (Germany). Forschungszentrum fuer Nachhaltige Energietechnik; Kluge, Juergen [Doppelacker GmbH, Petershagen-Eggersdorf (Germany)

2013-03-01

An ecovillage with highly efficient residential buildings is arisen in the Swabian community Wuestenrot. The power generation in these residential buildings by means of photovoltaic power plants is greater than the energy consumption. Decentralized heat plants supply thermal energy for the space heating and industrial waste. Central agrothermal collectors provide the necessary low-temperature heat for the effective operation of heat pumps over a so-called cold heat grid.

Reflective photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Lentine, Anthony L.; Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Goeke, Ronald S.

2018-03-06

A photovoltaic module includes colorized reflective photovoltaic cells that act as pixels. The colorized reflective photovoltaic cells are arranged so that reflections from the photovoltaic cells or pixels visually combine into an image on the photovoltaic module. The colorized photovoltaic cell or pixel is composed of a set of 100 to 256 base color sub-pixel reflective segments or sub-pixels. The color of each pixel is determined by the combination of base color sub-pixels forming the pixel. As a result, each pixel can have a wide variety of colors using a set of base colors, which are created, from sub-pixel reflective segments having standard film thicknesses.

Design and Implementation of a Simulator for Photovoltaic Modules

Directory of Open Access Journals (Sweden)

Kuang-Hui Tang

2012-01-01

Full Text Available Proposed in this paper is the development of a photovoltaic module simulator, one capable of running an output characteristic simulation under normal operation according to various electrical parameters specified and exhibiting multiple advantages of being low cost, small sized, and easy to implement. In comparison with commercial simulation tools, Pspice and Solar Pro, the simulator developed demonstrates a comparable I-V as well as a P-V output characteristic curve. In addition, a series-parallel configuration of individual modules constitutes a photovoltaic module array, which turns into a photovoltaic power generation system with an integrated power conditioner.

Photovoltaic solar concentrator

Science.gov (United States)

Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J.; Sanchez, Carlos Anthony; Clews, Peggy J.; Gupta, Vipin P.

2015-09-08

A process including forming a photovoltaic solar cell on a substrate, the photovoltaic solar cell comprising an anchor positioned between the photovoltaic solar cell and the substrate to suspend the photovoltaic solar cell from the substrate. A surface of the photovoltaic solar cell opposite the substrate is attached to a receiving substrate. The receiving substrate may be bonded to the photovoltaic solar cell using an adhesive force or a metal connecting member. The photovoltaic solar cell is then detached from the substrate by lifting the receiving substrate having the photovoltaic solar cell attached thereto and severing the anchor connecting the photovoltaic solar cell to the substrate. Depending upon the type of receiving substrate used, the photovoltaic solar cell may be removed from the receiving substrate or remain on the receiving substrate for use in the final product.

Small reactors for low-temperature nuclear heat applications

International Nuclear Information System (INIS)

1988-06-01

In accordance with the Member States' calls for information exchange in the field of nuclear heat application (NHA) two IAEA meetings were organized already in 1976 and 1977. After this ''promising period'', the development of relevant programmes in IAEA Member States was slowed down and therefore only after several years interruption a new Technical Committee Meeting with a Workshop was organized in late 1983, to review the status of NHA, after a few new specific plans appeared in some IAEA Member States in the early 1980's for the use of heat from existing or constructed NPPs and for developing nuclear heating plants (NHP). In June 1987 an Advisory Group Meeting was convened in Winnipeg, Canada, to discuss and formulate a state-of-the-art review on ''Small Reactors for Low Temperature Nuclear Heat Application''. Information on this subject gained up to 1987 in the Member States whose experts attended this meeting is embodied in the present Technical Report. Figs and tabs

Cost and optimal feed-in tariff for small scale photovoltaic systems in China

International Nuclear Information System (INIS)

Rigter, Jasper; Vidican, Georgeta

2010-01-01

China has recently become a dominant player in the solar photovoltaic (PV) industry, producing more than one-third of the global supply of solar cells in 2008. However, as of 2008, less than 1% of global installations were based in China. Recently, the government has stated its grand ambitions of expanding the share of electricity derived from solar power. As part of this initiative, policy makers are currently in the process of drafting a feed-in tariff policy to support the development of the solar energy market. In this paper, we aim to calculate what the level of such a tariff should be. We develop a closed form equation for the cost of PV, and use forecasts on prices of solar systems to derive an optimal feed-in tariff, including a digression rate. The focus is on the potential of residential and small scale commercial solar PV installations. We show that the cost of small scale PV in China has decreased rapidly during the period 2005-2009. Our analysis also shows that optimal feed-in tariffs vary widely between regions within China, and that grid parity could be reached in large parts of the country depending on the expected escalation in electricity prices. (author)

A study of photovoltaic/thermal (PVT)-ground source heat pump hybrid system by using fuzzy logic control

International Nuclear Information System (INIS)

Andrew Putrayudha, S.; Kang, Eun Chul; Evgueniy, E.; Libing, Y.; Lee, Euy Joon

2015-01-01

Renewable Heat Obligation (RHO) implementation in every country becomes an important issue to utilize more renewable energy sources while reducing the usage of fossil fuel. In 2014, South Korea has a target that every commercial building construction that exceeding 10,000 m 2 has to have on-site new & renewable power generation such as combined heat in the beginning of 2016. Photovoltaic/Thermal (PVT) and Geothermal hybrid systems have been introduced in previous research (E.J. Lee et al.) and it showed a great result from its efficiency and also its power consumption for single and multi-building cases. In this paper, Fuzzy Logic control has been applied to optimize the energy consumption of the system. By comparing it with conventional on–off control, fuzzy logic control system shows a better result in reducing primary energy consumption for both heating and cooling systems annually. Two cases were introduced in this paper, GSHP system and PVT–GSHP system with both on–off and fuzzy logic applied respectively. As a result, it shows that fuzzy logic control consumed 13.3% less energy compared with on–off controller for GSHP system annually and 18.3% less energy compared to on–off controller for PVT–GSHP system annually. - Highlights: • Two renewable systems were designed to produce heating, cooling and electricity. • System optimization by applying Fuzzy Logic in terms of energy saving. • Conventional on–off control system vs advance fuzzy logic control system. • Assumption used based on previous research experience, guidelines.

The heat exchanger of small pellet boiler for phytomass

Science.gov (United States)

Mičieta, Jozef; Lenhard, Richard; Jandačka, Jozef

2014-08-01

Combustion of pellets from plant biomass (phytomass) causes various troubles. Main problem is slagging ash because of low melting temperature of ash from phytomass. This problem is possible to solve either improving energetic properties of phytomass by additives or modification of boiler construction. A small-scale boiler for phytomass is different in construction of heat exchanger and furnace mainly. We solve major problem - slagging ash, by decreasing combustion temperature via redesign of pellet burner and boiler body. Consequence of lower combustion temperature is also lower temperature gradient of combustion gas. It means that is necessary to design larger heat exchanging surface. We plane to use underfed burner, so we would utilize circle symmetry heat exchanger. Paper deals design of heat exchanger construction with help of CFD simulation. Our purpose is to keep uniform water flux and combustion gas flux in heat exchanger without zone of local overheating and excess cooling.

A study of a small nuclear power plant system for district heating

International Nuclear Information System (INIS)

Imamura, Mitsuru; Sato, Kotaro; Narabayashi, Tadashi; Shimazu, Yoichiro; Tsuji, Masashi

2008-01-01

We have studied nuclear power plant for district heating. Already some towns and villages in Hokkaido have requested small reactor for district heating. Using existing technology allows us to shorten development period and to keep a lid on development cost. We decided to develop new reactor based on 'MUTSU' reactor technology. 'MUTSU' had already proved its safety. And 'MUTSU' reactor was boron free reactor. It allows plant system to become more compact and simple. And load following capability by core reactivity become bigger. It means to reduce control rod movement. It leads to dependability enhancement. We calculated burn-up calculation of erbium addition fuel. In the result the core life became about 10 years. In the district heating system, there are not only district heating but also snow melting with warm water. It uses steam condenser's heat, which are only discharged now. This small plant has passive safety system. It is natural cooling of containment vessel. In case of loss of coolant accident, decay heat can remove by natural convection air cooling after 6 hours. Decay heat within 6 hours can remove by evaporative heat transfer of pool on containment vessel. (author)

Work-Function and Surface Energy Tunable Cyanoacrylic Acid Small-Molecule Derivative Interlayer on Planar ZnO Nanorods for Improved Organic Photovoltaic Performance.

Science.gov (United States)

Ambade, Swapnil B; Ambade, Rohan B; Bagde, Sushil S; Lee, Soo-Hyoung

2016-12-28

The issue of work-function and surface energy is fundamental to "decode" the critical inorganic/organic interface in hybrid organic photovoltaics, which influences important photovoltaic events like exciton dissociation, charge transfer, photocurrent (J sc ), open-circuit voltage (V oc ), etc. We demonstrate that by incorporating an interlayer of cyanoacrylic acid small molecular layer (SML) on solution-processed, spin-coated, planar ZnO nanorods (P-ZnO NRs), higher photovoltaic (PV) performances were achieved in both inverted organic photovoltaic (iOPV) and hybrid organic photovoltaic (HOPV) devices, where ZnO acts as an "electron-transporting layer" and as an "electron acceptor", respectively. For the tuned range of surface energy from 52.5 to 33 mN/m, the power conversion efficiency (PCE) in bulk heterojunction (BHJ) iOPVs based on poly(3-hexylthiophene) (P3HT) and phenyl-C 60 -butyric acid methyl ester (PC 60 BM) increases from 3.16% to 3.68%, and that based on poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene)-2-carboxylate-2-6-diyl)] (PTB7:Th):[6,6]-phenyl C 71 butyric acid methyl ester (PC 71 BM) photoactive BHJ increases from 6.55% to 8.0%, respectively. The improved PV performance in iOPV devices is majorly attributed to enhanced photocurrents achieved as a result of reduced surface energy and greater electron affinity from the covalent attachment of the strong electron-withdrawing cyano moiety, while that in HOPV devices, where PCE increases from 0.21% to 0.79% for SML-modified devices, is ascribed to a large increase in V oc benefitted due to reduced work function effected from the presence of strong dipole moment in SML that points away from P-ZnO NRs.

Snow melting system with electric heating using photovoltaic power generation; Solar yusetsuko

Energy Technology Data Exchange (ETDEWEB)

Sasaki, M; Fujita, S; Kaga, T; Koyama, N [Hachinohe Institute of Technology, Aomori (Japan)

1996-10-27

This paper clarifies the solar characteristics in Hachinohe district, to investigate a possibility of the snow melting system with electric heating using solar energy. Power demand for snow melting, power generated by the photovoltaic (PV) array, area of PV array, and working conditions of the system, as to temperature, precipitation and snowfall, were investigated. The percentage of sunshine is 44% in Hachinohe district, which has more fortunate natural condition for utilizing solar radiation compared with that of 20% in Aomori prefecture. The intensity of solar radiation in winter from December to March is around 500 W/m{sup 2} in average, which is equivalent to the quantity of solar radiation, around 2 kWh/m{sup 2} a day. When assuming that snow on the road surface is frozen at the snowfall under the air temperature below -3{degree}C, the occurrence frequency is 50% during January and February in Hachinohe district, which means one frozen day for two days and is equivalent to the occurrence frequency of frozen days, 34% in average during winter. The electric application ratio is 0.34 at the maximum in winter. That is, days of 34% for one month are required for snow melting. 3 figs., 3 tabs.

Thermal analysis of a multi-layer microchannel heat sink for cooling concentrator photovoltaic (CPV) cells

Science.gov (United States)

Siyabi, Idris Al; Shanks, Katie; Mallick, Tapas; Sundaram, Senthilarasu

2017-09-01

Concentrator Photovoltaic (CPV) technology is increasingly being considered as an alternative option for solar electricity generation. However, increasing the light concentration ratio could decrease the system output power due to the increase in the temperature of the cells. The performance of a multi-layer microchannel heat sink configuration was evaluated using numerical analysis. In this analysis, three dimensional incompressible laminar steady flow model was solved numerically. An electrical and thermal solar cell model was coupled for solar cell temperature and efficiency calculations. Thermal resistance, solar cell temperature and pumping power were used for the system efficiency evaluation. An increase in the number of microchannel layers exhibited the best overall performance in terms of the thermal resistance, solar cell temperature uniformity and pressure drop. The channel height and width has no effect on the solar cell maximum temperature. However, increasing channel height leads to a reduction in the pressure drop and hence less fluid pumping power.

Initial crystallographic studies of a small heat-shock protein from Xylella fastidiosa

International Nuclear Information System (INIS)

Tada, Susely F. S.; Saraiva, Antonio Marcos; Lorite, Gabriela S.; Rosselli-Murai, Luciana K.; Pelloso, Alexandre César; Santos, Marcelo Leite dos; Trivella, Daniela B. B.; Cotta, Mônica A.; Souza, Anete Pereira de; Aparicio, Ricardo

2012-01-01

Initial crystallographic studies of the X. fastidiosa small heat-shock protein HSP17.9 are reported. The ORF XF2234 in the Xylella fastidiosa genome was identified as encoding a small heat-shock protein of 17.9 kDa (HSP17.9). HSP17.9 was found as one of the proteins that are induced during X. fastidiosa proliferation and infection in citrus culture. Recombinant HSP17.9 was crystallized and surface atomic force microscopy experiments were conducted with the aim of better characterizing the HSP17.9 crystals. X-ray diffraction data were collected at 2.7 Å resolution. The crystal belonged to space group P4 3 22, with unit-cell parameters a = 68.90, b = 68.90, c = 72.51 Å, and is the first small heat-shock protein to crystallize in this space group

Feasibility and parametric evaluation of hybrid concentrated photovoltaic-thermoelectric system

DEFF Research Database (Denmark)

Rezaniakolaei, Alireza; Rosendahl, Lasse Aistrup

2017-01-01

Concentrated photovoltaic (CPV) system integrated with thermoelectric generators (TEGs) is a novel technology that has potential to offer high efficient system. In this study, a thermally coupled model of concentrated photovoltaic-thermoelctric (CPV/TEG) system is established to investigate...... feasibility of the hybrid system over wide range of solar concentrations and different types of heat sinks. The model takes into account critical design parameters in the CPV and the TEG module. The results of this study show that for thermoelectric materials with ZT ≈ 1, the CPV/TEG system is more efficient...

Thermoeconomic Modeling and Parametric Study of a Photovoltaic-Assisted 1 MWe Combined Cooling, Heating, and Power System

Directory of Open Access Journals (Sweden)

Alexandros Arsalis

2016-08-01

Full Text Available In this study a small-scale, completely autonomous combined cooling, heating, and power (CCHP system is coupled to a photovoltaic (PV subsystem, to investigate the possibility of reducing fuel consumption. The CCHP system generates electrical energy with the use of a simple gas turbine cycle, with a rated nominal power output of 1 MWe. The nominal power output of the PV subsystem is examined in a parametric study, ranging from 0 to 600 kWe, to investigate which configuration results in a minimum lifecycle cost (LCC for a system lifetime of 20 years of service. The load profile considered is applied for a complex of households in Nicosia, Cyprus. The solar data for the PV subsystem are taken on an hourly basis for a whole year. The results suggest that apart from economic benefits, the proposed system also results in high efficiency and reduced CO2 emissions. The parametric study shows that the optimum PV capacity is 300 kWe. The minimum lifecycle cost for the PV-assisted CCHP system is found to be 3.509 million €, as compared to 3.577 million € for a system without a PV subsystem. The total cost for the PV subsystem is 547,445 €, while the total cost for operating the system (fuel is 731,814 € (compared to 952,201 € for a CCHP system without PVs. Overall the proposed system generates a total energy output of 210,520 kWh (during its whole lifetime, which translates to a unit cost of 17 €/kWh.

Vacuum-Ultraviolet Photovoltaic Detector.

Science.gov (United States)

Zheng, Wei; Lin, Richeng; Ran, Junxue; Zhang, Zhaojun; Ji, Xu; Huang, Feng

2018-01-23

Over the past two decades, solar- and astrophysicists and material scientists have been researching and developing new-generation semiconductor-based vacuum ultraviolet (VUV) detectors with low power consumption and small size for replacing traditional heavy and high-energy-consuming microchannel-detection systems, to study the formation and evolution of stars. However, the most desirable semiconductor-based VUV photovoltaic detector capable of achieving zero power consumption has not yet been achieved. With high-crystallinity multistep epitaxial grown AlN as a VUV-absorbing layer for photogenerated carriers and p-type graphene (with unexpected VUV transmittance >96%) as a transparent electrode to collect excited holes, we constructed a heterojunction device with photovoltaic detection for VUV light. The device exhibits an encouraging VUV photoresponse, high external quantum efficiency (EQE) and extremely fast tempera response (80 ns, 10 4 -10 6 times faster than that of the currently reported VUV photoconductive devices). This work has provided an idea for developing zero power consumption and integrated VUV photovoltaic detectors with ultrafast and high-sensitivity VUV detection capability, which not only allows future spacecraft to operate with longer service time and lower launching cost but also ensures an ultrafast evolution of interstellar objects.

Photovoltaic solar energy; Photovoltaische Solarenergie

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-01

for a renewable power supply? (G. Bopp); (17) Electrochemical energy storage for a stationary intermediate storage - Concepts and perspectives (M. Wohlfahrt-Mehrens); (18) Decentral photovoltaics: Autonomy, own consumption and grid relief by means of local power and heat storage systems (J. Binder); (19) Maximization of the lifetime of electric batteries in PV systems by means of battery hybrid storage systems (V. Spaeth); (20) Possibilities for grid integration of a high amount of photovoltaic power plants in the area of low performance (G. Wirth); (21) Change of load of grid components at the implementation of photovoltaic power into the power distribution system (G. Herold); (22) Feeding management and limitation of the supply of the active power to 70 % according to the new EEG 2012 (A. Umland); (23) Power quality and dynamic grid support: Do the medium voltage regulations correspond to the properties of PV inverters? (G. Doetter); (24) Perspectives of wafer based solar modules, technology and costs (R. Brendel); (25) Why is solar power not climate neutral but still environmentally friendly? Actual ecobalances to photovoltaics (M. Stucki); (26) Are photovoltaic power plants ''highly dangerous''? (H. Laukamp); (27) Power-to-Gas - Storage of renewable energies in the natural gas distribution system (M. Specht); (28) Utilization of own photovoltaic power - Fluctuation of radiation and load (B. Wille-Haussmann); (29) Arc detection in photovoltaic power plants - A system comparison between USA and Europe (A. Haeing); (30) 20 years 1,000 roofs program - Long-term experiences from Saxonia (M. Reiner); (31) Quality assurance of PV inverters - 20 years of field experiences with photovoltaic power plants in grid interconnection (J. Laschinski); (32) Experiences with the installation and operation of photovoltaic storage systems: Field tests of Sol-ion systems in southern Germany, Guadeloupe, Martinique and at research institutes (H.-D. Mohring); (33) Do

基于太阳能光伏光热组件的双热源热泵机组的实验研究%Experimental Research of Dual-source Heat Pump Unit Based on Solar Photovoltaic and Photothermal Component

Institute of Scientific and Technical Information of China (English)

陈剑波; 孙坤; 聂琳杰; 陈雷田

2015-01-01

本文基于太阳能光伏光热一体化系统,设计出应用太阳能光伏光热及空气源的双热源热泵机组。使热泵与太阳能光伏光热组件结合组成太阳能热泵系统,利用太阳能光伏光热组件( PV/T)内循环水及空气源的能量制取生活热水,同时降低太阳能光伏光热组件内循环水的温度,从而降低太阳能光伏板的温度。通过实验测得机组在水冷蒸发侧进水温度20℃,热水出水温度50℃的额定工况下,制冷量为2.855 kW,制热量为3.594 kW,COP为3.6。机组在水-水工况及水-风工况下运行的节能性研究结果表明,相对于单一空气源热泵,双热源热泵机组在满足家庭用生活热水需求的前提下,利用热泵技术回收太阳能光伏光热的热量制取生活热水节能性显著。%Based on the solar photovoltaic-thermal integrated system, we designed a dual-source, i. e. , solar photovoltaic-thermal and air source, heat pump unit. The unit becomes solar assisted heat pump system when combined with solar photovoltaic thermal unit, which produces domestic hot water by air source and circulating water in the solar photovoltaic solar-thermal components ( PV/T) and reduces circulating water temperature and solar photovoltaic panel temperature. We drew the conclusion by experiment that when the inflow water temperature is 20 ℃ on the evaporation side and the outflow hot water temperature is 50 ℃ under the rated conditions, the unit capacity is 2. 855 kW for refrigeration and 3. 594 kW for heating, and the COP is 3. 6. When the unit operates in the water-water condition and wa-ter-air condition, the experiment result shows the dual-source heat pump unit has remarkable energy-saving compared with single air source heat pump when the photovoltaic-thermal solar heat is used for domestic hot water.

Thin Film Photovoltaic Partnership Project | Photovoltaic Research | NREL

Science.gov (United States)

Thin Film Photovoltaic Partnership Project Thin Film Photovoltaic Partnership Project NREL's Thin Film Photovoltaic (PV) Partnership Project led R&D on emerging thin-film solar technologies in the United States from 1994 to 2009. The project made many advances in thin-film PV technologies that allowed

Standard Practice for Visual Inspections of Photovoltaic Modules

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This practice covers procedures and criteria for visual inspections of photovoltaic modules. 1.2 Visual inspections of photovoltaic modules are normally performed before and after modules have been subjected to environmental, electrical, or mechanical stress testing, such as thermal cycling, humidity-freeze cycling, damp heat exposure, ultraviolet exposure, mechanical loading, hail impact testing, outdoor exposure, or other stress testing that may be part of photovoltaic module testing sequence. 1.3 This practice does not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of this practice. 1.4 There is no similar or equivalent ISO standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Reactor waste heat utilization and district heating reactors. Nuclear district heating in Sweden - Regional reject heat utilization schemes and small heat-only reactors

International Nuclear Information System (INIS)

Hannerz, K.; Larsson, Y.; Margen, P.

1977-01-01

A brief review is given of the current status of district heating in Sweden. In future, district heating schemes will become increasingly interesting as a means of utilizing heat from nuclear reactors. Present recommendations in Sweden are that large reactors should not be located closer than about 20 km from large population centres. Reject heat from such reactors is cheap at source. To minimize the cost of long distance hot water transmission large heat rates must be transmitted. Only areas with large populations can meet this requirement. The three areas of main interest are Malmoe/Lund/Helsingborg housing close to 0.5 million; Greater Stockholm housing 1 to 1.5 million and Greater Gothenburg housing about 0.5 million people. There is an active proposal that the Malmoe/Lund/Helsingborg region would be served by a third nuclear unit at Barsebaeck, located about 20 km from Malmoe/Lund and supplying 950 MW of base load heat. Preliminary proposals for Stockholm involve a 2000 MW heat supply; proposals for Gothenburg are more tentative. The paper describes progress on these proposals and their technology. It also outlines technology under development to increase the economic range of large scale heat transport and to make distribution economic even for low heat-density family housing estates. Regions apart from the few major urban areas mentioned above require the adoption of a different approach. To this end the development of a small, simple low-temperature reactor for heat-only production suitable for urban location has been started in Sweden in close contact with Finland. Some results of the work in progress are presented, with emphasis on the safety requirements. An outline is given in the paper as to how problems of regional heat planning and institutional and legislative issues are being approached

High-Efficiency Small-Scale Combined Heat and Power Organic Binary Rankine Cycles

OpenAIRE

Costante Mario Invernizzi; Nadeem Ahmed Sheikh

2018-01-01

Small-CHP (Combined Heat and Power) systems are generally considered a valuable technological option to the conventional boilers, in a technology developed context. If small-CHP systems are associated with the use of renewable energies (biomass, for example) they could play an important role in distributed generation even in developing countries or, in any case, where there are no extensive electricity networks. Traditionally the considered heat engines for micro- or mini-CHP are: the gas eng...

The photovoltaic pilot projects of the European Community

Science.gov (United States)

Schnell, W.

The Commission of the European Communities has started in 1980 a programme for the design and construction of a series of photovoltaic pilot projects in the range of 30-300 kWp. Virtually all important industries and other development organisations in Europe working on photovoltaic cells and systems are involved in this programme. The different technologies which are being developed concern the modules, the cabling of the array, structure design, storage strategy and power conditioning. The various applications include powering of an island, villages, recreation centres, water desalination and disinfection, powering of radio transmitters, emergency power plants, dairy farm, training school, cooling, water pumping, powering of a solar heated swimming pool and last but not least, hydrogen production.

Thermocleavable pi-Conjugated polymers. Synthesis and photovoltaic applications

Energy Technology Data Exchange (ETDEWEB)

Helgesen, M

2009-10-15

Polymer solar cells (plastic solar cells) have seen remarkable improvements in recent years where power conversion efficiencies of up to 6% have been reported for small area devices. However in terms of stability polymer solar cells degrade during illumination and in the dark leading to operational lifetimes that are generally very poor. There has been a recent interest in the operational stability of devices and more importantly on the understanding of why devices and materials break down. This has lead to the discovery of a new class of materials that enable exceptionally long device lifetimes (>20000 hours). This Ph.D. thesis describes the synthesis, characterization and photovoltaic applications of these novel polymer materials. A key feature of these materials is that solubilizing thermocleavable alkyl ester side chains are introduced on the polymer backbone. The side chains make the polymer soluble in organic solvents and allow film formation via solution processing. Subsequently they can be removed by heating in a post-processing step forming a harder insoluble material with enhanced stability. These new thermocleavable materials can potentially offer higher chromophore density, higher level processing and improved stability in a solar cell device. Methods are developed for the incorporation of alkoxy chains and thermocleavable ester groups on the benzothiadiazole and the thiophene units in an attempt to evolve the PDTBT system to a more advanced level. The synthesis and photovoltaic applications of the PDTTP and PDTBT systems is described. (author)

Evaluation of external heat loss from a small-scale expander used in organic Rankine cycle

International Nuclear Information System (INIS)

Li Jing; Pei Gang; Li Yunzhu; Ji Jie

2011-01-01

With the scaling down of the Organic Rankine Cycle (ORC), the engine shaft power is not only determined by the enthalpy drop in the expansion process but also the external heat loss from the expander. Theoretical and experimental support in evaluating small-scale expander heat loss is rare. This paper presents a quantitative study on the convection, radiation, and conduction heat transfer from a kW-scale expander. A mathematical model is built and validated. The results show that the external radiative or convective heat loss coefficient was about 3.2 or 7.0 W/K.m 2 when the ORC operated around 100 o C. Radiative and convective heat loss coefficients increased as the expander operation temperature increased. Conductive heat loss due to the connection between the expander and the support accounted for a large proportion of the total heat loss. The fitting relationships between heat loss and mean temperature difference were established. It is suggested that low conductivity material be embodied in the support of expander. Mattress insulation for compact expander could be eliminated when the operation temperature is around 100 o C. - Highlights: → A close examination of external heat loss from a small expander is presented. → Theoretical analysis and experimental test were conducted. → The established formulas can be applied to other small ORC expanders. → The results are useful in further research of small-scale ORC.

Photovoltaic module and laminate

Science.gov (United States)

Bunea, Gabriela E.; Kim, Sung Dug; Kavulak, David F.J.

2018-04-10

A photovoltaic module is disclosed. The photovoltaic module has a first side directed toward the sun during normal operation and a second, lower side. The photovoltaic module comprises a perimeter frame and a photovoltaic laminate at least partially enclosed by and supported by the perimeter frame. The photovoltaic laminate comprises a transparent cover layer positioned toward the first side of the photovoltaic module, an upper encapsulant layer beneath and adhering to the cover layer, a plurality of photovoltaic solar cells beneath the upper encapsulant layer, the photovoltaic solar cells electrically interconnected, a lower encapsulant layer beneath the plurality of photovoltaic solar cells, the upper and lower encapsulant layers enclosing the plurality of photovoltaic solar cells, and a homogenous rear environmental protection layer, the rear environmental protection layer adhering to the lower encapsulant layer, the rear environmental protection layer exposed to the ambient environment on the second side of the photovoltaic module.

Optimal Scheduling of Integrated Energy Systems with Combined Heat and Power Generation, Photovoltaic and Energy Storage Considering Battery Lifetime Loss

Directory of Open Access Journals (Sweden)

Yongli Wang

2018-06-01

Full Text Available Integrated energy systems (IESs are considered a trending solution for the energy crisis and environmental problems. However, the diversity of energy sources and the complexity of the IES have brought challenges to the economic operation of IESs. Aiming at achieving optimal scheduling of components, an IES operation optimization model including photovoltaic, combined heat and power generation system (CHP and battery energy storage is developed in this paper. The goal of the optimization model is to minimize the operation cost under the system constraints. For the optimization process, an optimization principle is conducted, which achieves maximized utilization of photovoltaic by adjusting the controllable units such as energy storage and gas turbine, as well as taking into account the battery lifetime loss. In addition, an integrated energy system project is taken as a research case to validate the effectiveness of the model via the improved differential evolution algorithm (IDEA. The comparison between IDEA and a traditional differential evolution algorithm shows that IDEA could find the optimal solution faster, owing to the double variation differential strategy. The simulation results in three different battery states which show that the battery lifetime loss is an inevitable factor in the optimization model, and the optimized operation cost in 2016 drastically decreased compared with actual operation data.

Technological status of organic photovoltaics (OPV)

DEFF Research Database (Denmark)

Carlé, Jon Eggert; Krebs, Frederik C

2013-01-01

This paper gives a technological status of organic and polymer photovoltaics (OPV) for both single and tandem junctions. We list the current state-of-the-art at the laboratory level for very small rigid and mostly vacuum processed devices to larger area flexible and printed devices. In comparison...

Thermal resistance analysis and optimization of photovoltaic-thermoelectric hybrid system

International Nuclear Information System (INIS)

Yin, Ershuai; Li, Qiang; Xuan, Yimin

2017-01-01

Highlights: • A detailed thermal resistance analysis of the PV-TE hybrid system is proposed. • c-Si PV and p-Si PV cells are proved to be inapplicable for the PV-TE hybrid system. • Some criteria for selecting coupling devices and optimal design are obtained. • A detailed process of designing the practical PV-TE hybrid system is provided. - Abstract: The thermal resistance theory is introduced into the theoretical model of the photovoltaic-thermoelectric (PV-TE) hybrid system. A detailed thermal resistance analysis is proposed to optimize the design of the coupled system in terms of optimal total conversion efficiency. Systems using four types of photovoltaic cells are investigated, including monocrystalline silicon photovoltaic cell, polycrystalline silicon photovoltaic cell, amorphous silicon photovoltaic cell and polymer photovoltaic cell. Three cooling methods, including natural cooling, forced air cooling and water cooling, are compared, which demonstrates a significant superiority of water cooling for the concentrating photovoltaic-thermoelectric hybrid system. Influences of the optical concentrating ratio and velocity of water are studied together and the optimal values are revealed. The impacts of the thermal resistances of the contact surface, TE generator and the upper heat loss thermal resistance on the property of the coupled system are investigated, respectively. The results indicate that amorphous silicon PV cell and polymer PV cell are more appropriate for the concentrating hybrid system. Enlarging the thermal resistance of the thermoelectric generator can significantly increase the performance of the coupled system using amorphous silicon PV cell or polymer PV cell.

A study of a small nuclear power plant system for district heating

International Nuclear Information System (INIS)

Imamura, Mitsuru; Sato, Kotaro; Narabayashi, Tadashi; Shimazu, Yoichiro; Tsuji, Masashi

2009-01-01

We have studied nuclear power plant for district heating. Already some towns and villages in Hokkaido have requested small reactor for district heating. Using existing technology allows us to shorten development period and to keep a lid on development cost. We decided to develop new reactor based on 'MUTSU' reactor technology because 'MUTSU' had already proved its safety. And this reactor was boron free reactor. It allows plant system to reduce the chemical control system. And moderator temperature coefficient is deeply negative. It means to improve its operability and leads to dependability enhancement. We calculated burn-up calculation of erbium addition fuel. In the result, the core life became about 10 years. And we adapt the cassette type refueling during outagein in order to maintain nonproliferation. In the district heating system, a double heat exchanger system enables to response to load change in season. To obtain the acceptance of public, this system has a leak prevention system of radioactive materials to public. And road heating system of low grade heat utilization from turbine condenser leads to improve the heat utilization efficiency. We carried out performance evaluation test of district heating pipeline. Then the heat loss of pipeline is estimated at about 0.440degC/km. This result meets general condition, which is about 1degC/km. This small plant has passive safety system. It is natural cooling of containment vessel. In case of loss of coolant accident, decay heat can remove by natural convection air cooling after 6 hours. Decay heat within 6 hours can remove by evaporative heat transfer of pool on containment vessel. (author)

Photovoltaic research and development in Japan

Science.gov (United States)

Shimada, K.

1983-01-01

The status of the Japanese photovoltaic (PV) R&D activities was surveyed through literature searches, private communications, and site visits in 1982. The results show that the Japanese photovoltaic technology is maturing rapidly, consistent with the steady government funding under the Sunshine Project. Two main thrusts of the Project are: (1) completion of the solar panel production pilot plants using cast ingot and sheet silicon materials, and (2) development of large area amorphous silicon solar cells with acceptable efficiency (10 to 12%). An experimental automated solar panel production plant rated at 500 kW/yr is currently under construction for the Sunshine Project for completion in March 1983. Efficiencies demonstrated by experimental large are amorphous silicon solar cells are approaching 8%. Small area amorphous silicon solar cells are, however, currently being mass produced and marketed by several companies at an equivalent annual rate of 2 MW/yr for consumer electronic applications. There is no evidence of an immediate move by the Japanese PV industry to enter extensively into the photovoltaic power market, domestic or otherwise. However, the photovoltaic technology itself could become ready for such an entry in the very near future, especially by making use of advanced process automation technologies.

Commercial Application of a Photovoltaic Concentrator system. Phase I. Final report, 1 June 1978-28 February 1979

Energy Technology Data Exchange (ETDEWEB)

Anderson, D.J.; Anderson, E.R.; Bardwell, K.M.

1980-04-01

This report documents the design and analysis of the BDM CAPVC (Commercial Application of a Photovoltaic Concentrator) system. The preliminary design, prototype test and evaluation, system analysis, and final design of a large-scale concentrating photovoltaic system are described. The application is on an attractive new office building which represents a large potential market. The photovoltaic concentrating array is a roof-mounted, single-axis linear parabolic trough, using single crystalline silicon photovoltaic cells. A total of 6720 square feet of aperture is focussed on 13,944 PV cells. The photovoltaic system operates in parallel with the local utility in an augmentary loadsharing operating mode. The array is actively cooled and the thermal energy utilized for building heat during winter months. (WHK)

A new future for the French photovoltaic industry

International Nuclear Information System (INIS)

Laborde, E.

2009-01-01

The French photovoltaic industry counts two major players: Photowatt and Tenesol (formerly Total-energy). Specialized in distribution networks and systems engineering, Tenesol has recently become involved in assembling photovoltaic panels; it holds a strong position in its historical markets (France's overseas territories and departments). Photowatt, now celebrating its 30. birthday, is the only French manufacturer of solar wafers, cells and modules. It represents the core of France's photovoltaic industry. Although some small businesses are emerging in this sector, very few of them are involved in technological activities capable of achieving an industrial scale. For a long time, Photowatt has been leading the market and has even risen to number five worldwide. It is thriving thanks to niche markets (isolated sites, solar pumps) with public funding (national or international). (author)

Present condition and the future of photovoltaic generating systems. Part 5. Future perspective of photovoltaic power systems; Taiyo hikarihatsuden system no genjo to shorai. 5. Taiyo hikarihatsuden system no shorai tenbo

Energy Technology Data Exchange (ETDEWEB)

Horigome, T

1994-12-20

In this paper, as the future perspective of photovoltaic power systems, the establishment of the legal environment for the popularization of the photovoltaic power systems in large amounts and the future prediction of the popularization of power generation are described. Specially the following grand ideas are introduced: building in high seas regeneratable energy transformation plants with solar energy as the main energy, generating combined power of photovoltaic, solar heat, wave and temperature difference of the sea water, biomass, solar-bio power generating without CO2 exhaustion, building hard solar plants to produce electricity, hydrogen, methanol and fresh water from regeneratable energy, and breeding fish, shells and see weed in the sea pasture land under the plants, which are the so called `Energy sea pasture high breed plants (REPO Plan)` and also space power generating i.e. setting up special satellites for solar power generation in synchronous orbits, generating power through solar batteries or solar heat and then transmitting it to the earth through microwave. 12 refs., 4 figs.

Photovoltaic module and interlocked stack of photovoltaic modules

Science.gov (United States)

Wares, Brian S.

2012-09-04

One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame having at least a top member and a bottom member. A plurality of alignment features are included on the top member of each frame, and a plurality of alignment features are included on the bottom member of each frame. Adjacent photovoltaic modules are interlocked by the alignment features on the top member of a lower module fitting together with the alignment features on the bottom member of an upper module. Other embodiments, features and aspects are also disclosed.

Simplified analysis of passive residual heat removal systems for small size PWR's

International Nuclear Information System (INIS)

Botelho, D.A.

1992-02-01

The function and general objectives of a passive residual heat removal system for small size PWR's are defined. The characteristic configuration, the components and the operation modes of this system are concisely described. A preliminary conceptual specification of this system, for a small size PWR of 400 MW thermal, is made analogous to the decay heat removal system of the AP-600 reactor. It is shown by analytic models that such passive systems can dissipate 2% of nominal power within the thermal limits allowed to the reactor fuel elements. (author)

Performance of double -pass solar collector with CPC and fins for heat transfer enhancement

Science.gov (United States)

Alfegi, Ebrahim M. A.; Abosbaia, Alhadi A. S.; Mezughi, Khaled M. A.; Sopian, Kamaruzzaman

2013-06-01

The temperature of photovoltaic modules increases when it absorbs solar radiation, causing a decrease in efficiency. This undesirable effect can be partially avoided by applying a heat recovery unit with fluid circulation (air or water) with the photovoltaic module. Such unit is called photovoltaic / thermal collector (pv/t) or hybrid (pv/t). In this unit, photovoltaic cells were pasted directly on the flat plate absorber. An experimental study of a solar air heater with photovoltaic cell located at the absorber with fins and compound parabolic collector for heat transfer enhancement and increasing the number of reflection on the cells have been conducted. The performance of the photovoltaic, thermal, and combined pv/t collector over range of operating conditions and the results was discussed. Results at solar irradiance of 500 W/m2 show that the combined pv/t efficiency is increasing from 37.28 % to 81.41 % at mass flow rates various from 0.029 to 0.436 kg/s.

A photovoltaic module

DEFF Research Database (Denmark)

2013-01-01

The present invention relates to a photovoltaic module comprising a carrier substrate, said carrier substrate carrying a purely printed structure comprising printed positive and negative module terminals, a plurality of printed photovoltaic cell units each comprising one or more printed...... photovoltaic cells, wherein the plurality of printed photovoltaic cell units are electrically connected in series between the positive and the negative module terminals such that any two neighbouring photovoltaic cell units are electrically connected by a printed interconnecting electrical conductor....... The carrier substrate comprises a foil and the total thickness of the photovoltaic module is below 500 [mu]m. Moreover, the nominal voltage level between the positive and the negative terminals is at least 5 kV DC....

Photovoltaic device

Energy Technology Data Exchange (ETDEWEB)

Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R

2017-03-21

The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

Photovoltaic device

Science.gov (United States)

Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

2015-06-02

The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

Photovoltaic-Thermal New Technology Demonstration

Energy Technology Data Exchange (ETDEWEB)

Dean, Jesse [National Renewable Energy Laboratory (NREL), Golden, CO (United States); McNutt, Peter [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lisell, Lars [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Burch, Jay [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jones, Dennis [Group14 Engineering, Inc., Denver, CO (United States); Heinicke, David [Group14 Engineering, Inc., Denver, CO (United States)

2015-01-01

Photovoltaic-thermal (PV-T) hybrid solar systems offer increased electricity production by cooling the PV panel, and using the removed thermal energy to heat water - all in the same footprint as a standard PV system. GPG's assessment of the nation's first large-scale PV-T system installed at the Thomas P. O'Neill, Jr. Federal Building in Boston, MA, provided numerous lessons learned in system design, and identified a target market of locations with high utility costs and electric hot water backup.

Hopes doomed for French photovoltaic

International Nuclear Information System (INIS)

Piro, P.

2013-01-01

The photovoltaic industry has lost 15000 jobs in 2 years in France and the emergency measures taken by French authorities seem to be not sufficient to curb the trend. Some measures have led to delay or even cancel some projects while what is the most important today is to generate enough activity in small and intermediate enterprises to safeguard jobs

Technologies for small scale wood-fueled combined heat and power systems

Energy Technology Data Exchange (ETDEWEB)

Houmann Jakobsen, H.; Houmoeller, S.; Thaaning Pedersen, L.

1998-01-01

The aim of this study is to describe and compare different technologies for small cogeneration systems (up to 2-3 MW{sub e}), based on wood as fuel. For decentralized cogeneration, i.e. for recovering energy from saw mill wood wastes or heat supply for small villages, it is vital to know the advantages and disadvantages of the different technologies. Also, for the decision-makers it is of importance to know the price levels of the different technologies. A typical obstacle for small wood cogeneration systems is the installation costs. The specific price (per kW) is usually higher than for larger plants or plants using fossil fuels. For a saw mill choosing between cogeneration and simple heat production, however, the larger installation costs are counter weighed by the sale of electricity, while the fuel consumption is the same. Whether it is profitable or not to invest in cogeneration is often hard to decide. For many years small wood cogeneration systems have been too expensive, leading to the construction of only heat producing systems due to too high price levels of small steam turbines. In recent years a great deal of effort has been put into research and developing of new technologies to replace this traditional steam turbine. Among these are: Steam engines; Stirling engines; Indirectly fired gas turbines; Pressurized down draft combustion. Along with the small scale traditional steam turbines, these technologies will be evaluated in this study. When some or all these technologies are fully developed and commercial, a strong means of reducing the strain on the environment and the greenhouse effect will be available, as the total efficiency is high (up to 90%) and wood is an energy source in balance with nature. (au) EFP-95. 19 refs.

Organic photovoltaics

DEFF Research Database (Denmark)

Demming, Anna; Krebs, Frederik C; Chen, Hongzheng

2013-01-01

's supply, even at our increasingly ravenous rate of global energy consumption [1]. But it's not what you have got it's what you do with it. Hence the intense focus on photovoltaic research to find more efficient ways to harness energy from the Sun. Recently much of this research has centred on organic...... solar cells since they offer simple, low-cost, light-weight and large-area flexible photovoltaic structures. This issue with guest editors Frederik C Krebs and Hongzheng Chen focuses on some of the developments at the frontier of organic photovoltaic technology. Improving the power conversion efficiency...... of organic photovoltaic systems, while maintaining the inherent material, economic and fabrication benefits, has absorbed a great deal of research attention in recent years. Here significant progress has been made with reports now of organic photovoltaic devices with efficiencies of around 10%. Yet operating...

Photovoltaic barometer

International Nuclear Information System (INIS)

2014-01-01

The global solar photovoltaic market enjoyed a strong revival in 2013. Preliminary estimates put it in excess of 37 GWp, compared to 30 GWp in 2012 and 2011. The solar photovoltaic sector led the annual installed capacity ratings for renewable energies, taking worldwide capacity up to 137 GWp by the end of the year which means a 35% year-on-year increase. At global level the high growth markets - China, Japan and America - contrast sharply with the contracting European Union market. The strong recovery of the global photovoltaic market is due to the drop in module prices which in some zones has dropped below the conventional electricity price. In the E.U, in 2013 the photovoltaic electricity reached 80.2 TWh while the capacity connected during this year was 9922.2 MWp. Concerning the capacity connected in 2013 the 2 main contributors in Europe are Germany (3310.0 MWc) and Italy (1462.0 MWc). These 2 countries represent also 68% of the cumulated and connected capacity in Europe. All along the article various charts and tables give the figures of the photovoltaic capacity per inhabitant for each E.U country in 2013, the electricity production from photovoltaic power for each E.U country, and the main photovoltaic module manufacturers in 2013 worldwide reporting production and turnover

Photovoltaic device

Science.gov (United States)

Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

2015-09-01

The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

Performance of a Solar Heating System with Photovoltaic Thermal Hybrid Collectors and Heat Pump

DEFF Research Database (Denmark)

Dannemand, Mark; Furbo, Simon; Perers, Bengt

2017-01-01

. When the solar collectors are unable to supply the heat demand an auxiliary heat source is used. Heat pumps can generate this heat. Liquid/water heat pumps have better performance than air/water heat pumps in cold climates but requires installation of a tubing system for the cold side of the heat pump....... The tubes are typically placed in the ground, requires a significant land area and increase the installation cost. A new system design of a solar heating system with two storage tanks and a liquid/water heat pump is presented. The system consists of PVT collectors that generate both heat and electricity......The energy consumption in buildings accounts for a large part of the World’s CO2 emissions. Much energy is used for appliances, domestic hot water preparation and space heating. In solar heating systems, heat is captured by solar collectors when the sun is shining and used for heating purposes...

Is the photovoltaic to be saved?; Faut-il sauver le Photovoltaique?

Energy Technology Data Exchange (ETDEWEB)

Nifenecker, H.

2011-07-01

This paper first proposes a critical overview of the current financial support given to the photovoltaic energy. He notably criticizes the obligation for EDF to purchase the electricity so produced, and the obtained results in terms of renewable energy production, emission reduction, development of the photovoltaic industry sector, and development of decentralized energy productions. He proposes a better philosophy for the development of solar energy in Europe: to use solar in energy rather in Spain than in northern Europe, to use solar energy for heating rather than for electricity production in France, to develop storage practices, to encourage self-consumption

Performance of double –pass solar collector with CPC and fins for heat transfer enhancement

International Nuclear Information System (INIS)

Alfegi, Ebrahim M A; Abosbaia, Alhadi A S; Mezughi, Khaled M A; Sopian, Kamaruzzaman

2013-01-01

The temperature of photovoltaic modules increases when it absorbs solar radiation, causing a decrease in efficiency. This undesirable effect can be partially avoided by applying a heat recovery unit with fluid circulation (air or water) with the photovoltaic module. Such unit is called photovoltaic / thermal collector (pv/t) or hybrid (pv/t). In this unit, photovoltaic cells were pasted directly on the flat plate absorber. An experimental study of a solar air heater with photovoltaic cell located at the absorber with fins and compound parabolic collector for heat transfer enhancement and increasing the number of reflection on the cells have been conducted. The performance of the photovoltaic, thermal, and combined pv/t collector over range of operating conditions and the results was discussed. Results at solar irradiance of 500 W/m 2 show that the combined pv/t efficiency is increasing from 37.28 % to 81.41 % at mass flow rates various from 0.029 to 0.436 kg/s.

Solar photovoltaic: a better tomorrow

International Nuclear Information System (INIS)

Signoret, Stephane

2016-01-01

This article comments statements and works performed by a professional body (Enerplan) and a think tank (FTS, France Territoire Solaire) which describe a glorious future for solar photovoltaic energy even though the present situation is rather dull. They foresee ground-based solar plants of more than 1 MW, and assess the potential production for very large, medium and small sized roofs, for domestic installations

Space Photovoltaic Concentrator Using Robust Fresnel Lenses, 4-Junction Cells, Graphene Radiators, and Articulating Receivers

Science.gov (United States)

O'Neill, Mark; McDanal, A. J.; Brandhorst, Henry; Spence, Brian; Iqbal, Shawn; Sharps, Paul; McPheeters, Clay; Steinfeldt, Jeff; Piszczor, Michael; Myers, Matt

2016-01-01

At the 42nd PVSC, our team presented recent advances in our space photovoltaic concentrator technology. These advances include more robust Fresnel lenses for optical concentration, more thermally conductive graphene radiators for waste heat rejection, improved color-mixing lens technology to minimize chromatic aberration losses with 4-junction solar cells, and an articulating photovoltaic receiver enabling single-axis sun-tracking, while maintaining a sharp focal line despite large beta angles of incidence. In the past year, under a NASA Phase II SBIR program, our team has made much additional progress in the development of this new space photovoltaic concentrator technology, as described in this paper.

Photovoltaic Cells

OpenAIRE

Karolis Kiela

2012-01-01

The article deals with an overview of photovoltaic cells that are currently manufactured and those being developed, including one or several p-n junction, organic and dye-sensitized cells using quantum dots. The paper describes the advantages and disadvantages of various photovoltaic cells, identifies the main parameters, explains the main reasons for the losses that may occur in photovoltaic cells and looks at the ways to minimize them.Article in Lithuanian

Thermal Fluid Analysis of the Heat Sink and Chip Carrier Assembly for a US Army Research Laboratory Liquid-Fueled Thermophotovoltaic Power Source Demonstrator

Science.gov (United States)

2016-09-01

temperatures above 500 °C.1 Figure 1 describes the primary components of a TPV system : a heat source, an emitter, and a photovoltaic converter. The heat...carrier surface not covered by the photovoltaic cell. 4. Mesh The mesh was set to level 3 with the minimum gap size manually set to 0.01 inch. A...heat sink to control the temperature of the photovoltaic cell while exposed to radiation from the emitter. 15. SUBJECT TERMS TPV

Heat transfer with water in forced convection without boiling in small diameter tubes

International Nuclear Information System (INIS)

Ricque, Roger; Siboul, Roger

1969-01-01

This note presents the measurements performed for the establishment of an empirical heat transfer law for water in forced convection without boiling in small diameter tubes (2 and 4 mm), with high flow velocity and strong heat flux, and for relatively low fluid temperatures. A correlation of experimental points is obtained with a very small maximum dispersion: Nu fl = 0,0092 Re fl 0,88 Pr 0,5 (μ fl /μ p ) 0,14 . A correlation for the fiction coefficient is also presented [fr

Photovoltaic barometer

International Nuclear Information System (INIS)

2013-01-01

After the euphoria of 2011, the European Union's photovoltaic market slowed right down in 2012. EurObserv'ER puts newly connected capacity in 2012 at 16.5 GWp compared to 22 GWp in 2011, which is a 25% drop. At global level the market generally held up, with just over 30 GWp installed, bolstered by the build-up of the American and Asian markets. The photovoltaic electricity generated in the EU reached 68.1 TWh in 2012. The article begins with the description of the worldwide situation of photovoltaic electricity, then details the situation for each EU member with the help of tables and charts and ends with the state of photovoltaic industry at the world scale

Hydrogen and renewable energy sources integrated system for greenhouse heating

Directory of Open Access Journals (Sweden)

Ileana Blanco

2013-09-01

Full Text Available A research is under development at the Department of Agro- Environmental Sciences of the University of Bari “Aldo Moro” in order to investigate the suitable solutions of a power system based on solar energy (photovoltaic and hydrogen, integrated with a geothermal heat pump for powering a self sustained heated greenhouse. The electrical energy for heat pump operation is provided by a purpose-built array of solar photovoltaic modules, which supplies also a water electrolyser system controlled by embedded pc; the generated dry hydrogen gas is conserved in suitable pressured storage tank. The hydrogen is used to produce electricity in a fuel cell in order to meet the above mentioned heat pump power demand when the photovoltaic system is inactive during winter night-time or the solar radiation level is insufficient to meet the electrical demand. The present work reports some theoretical and observed data about the electrolyzer operation. Indeed the electrolyzer has required particular attention because during the experimental tests it did not show a stable operation and it was registered a performance not properly consistent with the predicted performance by means of the theoretical study.

Photovoltaic panel clamp

Science.gov (United States)

Mittan, Margaret Birmingham [Oakland, CA; Miros, Robert H. J. [Fairfax, CA; Brown, Malcolm P [San Francisco, CA; Stancel, Robert [Loss Altos Hills, CA

2012-06-05

A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

Portable photovoltaic irrigation pumps

Energy Technology Data Exchange (ETDEWEB)

Furber, J. D.

1980-07-01

Experiences in developing a solar-powered irrigation pump to meet the needs of poor farmers in developing nations are summarized. The design which evolved is small and portable, employing a high-efficiency electric pump, powered by photovoltaic panels. Particular emphasis is placed on how the system works, and on early field problems experienced with the first prototypes. The resolution of these problems and the performance of actual systems in various countries is presented and user responses are noted.

Heat Loads Due To Small Penetrations In Multilayer Insulation Blankets

Science.gov (United States)

Johnson, W. L.; Heckle, K. W.; E Fesmire, J.

2017-12-01

The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to ease the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fourier’s Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at ∼76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

Costs comparison between solar photovoltaic system and moto-generator for supplying the isolated small community

International Nuclear Information System (INIS)

Fadigas, E.A.F.A.; Faga, M.T.W.

1993-01-01

This work describes a technical configuration from which making an economic evaluation that comparing the photovoltaic option with moto-generator, energy source very used in rural community, presenting the relations of implantation cost between two options, showing the sensibility of these cost in function of some variables like: demand, reduction tax, solar radiation, and, as the solar energy market photovoltaic presents cost upper than international cost due to the inexpressive scale economy, make the analysis with one prices range, possibility an evaluation not limited to the national market. 3 refs, 8 figs

Photovoltaic mounting/demounting unit

DEFF Research Database (Denmark)

2014-01-01

The present invention relates to a photovoltaic arrangement comprising a photovoltaic assembly comprising a support structure defining a mounting surface onto which a photovoltaic module is detachably mounted; and a mounting/demounting unit comprising at least one mounting/demounting apparatus...... which when the mounting/demounting unit is moved along the mounting surface, causes the photovoltaic module to be mounted or demounted to the support structure; wherein the photovoltaic module comprises a carrier foil and wherein a total thickness of the photo voltaic module is below 500 muiotaeta....... The present invention further relates to an associated method for mounting/demounting photovoltaic modules....

Small-scale automated biomass energy heating systems: a viable option for remote Canadian communities?

Energy Technology Data Exchange (ETDEWEB)

McCallum, B. [Canadian Forest Service, Ottawa, ON (Canada). Industry, Economics and Programs Branch

1997-12-31

The potential benefits of wood energy (forest biomass) for space heating in Canada`s remote communities was discussed. Diesel fuel and heating oil must be transported into these communities to produce electricity and to heat large public buildings. Below the treeline, roundwood is often used to heat private homes. The move toward environmentally sustainable development has focussed much attention on renewable energy technologies such as biomass energy, (i.e. any form of energy derived from plant or animal materials). Wood is the most readily available biomass fuel in remote communities. Woodchips and sawmill waste can be burned in automated biomass heating systems which provide a convenient way to use low-grade wood to heat large buildings or groups of buildings which would not be feasible to heat with roundwood. It was shown that one cord of spruce can produce 1.5 tonnes of woodchips to ultimately displace 300 litres of heating oil. A description of a small-commercial and small-industrial biomass system was presented. The benefits of biomass were described as: (1) direct savings compared to high-cost oil heat, (2) increased circulation of energy dollars inside the community, and (3) employment opportunities in harvesting, processing and operating biomass systems. A steady supply of good quality woodchips to the heating plant must be ensured. 1 ref., 3 figs.

Organic photovoltaic energy in Japan

International Nuclear Information System (INIS)

2007-01-01

Japan finances research programs on photovoltaic conversion since 1974. Research in this domain is one of the 11 priorities of NEDO, the agency of means of the ministry of economy, trade and industry of Japan. The search for an abatement of production costs and of an increase of cells efficiency is mentioned in NEDO's programs as soon as the beginning of the 1990's. A road map has been defined which foresees photovoltaic energy production costs equivalent to the ones of thermal conversion by 2030, i.e. 7 yen/kWh (4.4 cents of euro/kWh). The use of new materials in dye-sensitized solar cells (DSSC) or organic solar cells, and of new structures (multi-junctions) is explored to reach this objective. The organic photovoltaic technology is more particularly considered for small generation units in mobile or domestic technologies. Japan is particularly in advance in the improvement of DSSC cells efficiency, in particular in the domain of the research on solid electrolytes. Europe seems more in advance in the domain of the new generation of organic solar cells. Therefore, a complementarity may be found between Japan and French teams in the domain of organic solar cells improvement through collaboration programs. (J.S.)

Evaluation of optimal dual axis concentrated photovoltaic thermal system with active ventilation using Frog Leap algorithm

International Nuclear Information System (INIS)

Gholami, H.; Sarwat, A.I.; Hosseinian, H.; Khalilnejad, A.

2015-01-01

Highlights: • Electro-thermal performance of open-loop controlled dual axis CPVT is investigated. • For using the absorbed heat, active ventilation with a heat storage tank is used. • Economic optimization of the system is performed, using Frog Leap algorithm. • Detailed model of all sections is simulated with their characteristics evaluation. • Triple-junction photovoltaic cells, which are the most recent technology, are used. - Abstract: In this study, design and optimization of a concentrated photovoltaic thermal (CPVT) system considering electrical, mechanical, and economical aspects is investigated. For this purpose, each section of the system is simulated in MATLAB, in detail. Triple-junction photovoltaic cells, which are the most recent technology, are used in this study. They are more efficient in comparison to conventional photovoltaic cells. Unlike ordinary procedures, in this work active ventilation is used for absorbing the thermal power of radiation, using heat storage tanks, which not only results in increasing the electrical efficiency of the system through decreasing the temperature, but also leads to storing and managing produced thermal energy and increasing the total efficiency of the system up to 85 percent. The operation of the CPVT system is investigated for total hours of the year, considering the needed thermal load, meteorological conditions, and hourly radiation of Khuznin, a city in Qazvin province, Iran. Finally, the collector used for this system is optimized economically, using frog leap algorithm, which resulted in the cost of 13.4 $/m"2 for a collector with the optimal distance between tubes of 6.34 cm.

Building America Best Practices Series, Volume 6: High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems

Energy Technology Data Exchange (ETDEWEB)

Baechler, Michael C.; Gilbride, Theresa L.; Ruiz, Kathleen A.; Steward, Heidi E.; Love, Pat M.

2007-06-04

This guide is was written by PNNL for the US Department of Energy's Building America program to provide information for residential production builders interested in building near zero energy homes. The guide provides indepth descriptions of various roof-top photovoltaic power generating systems for homes. The guide also provides extensive information on various designs of solar thermal water heating systems for homes. The guide also provides construction company owners and managers with an understanding of how solar technologies can be added to their homes in a way that is cost effective, practical, and marketable. Twelve case studies provide examples of production builders across the United States who are building energy-efficient homes with photovoltaic or solar water heating systems.

Applications of photovoltaics

International Nuclear Information System (INIS)

Pearsall, N.

1999-01-01

The author points out that although photovoltaics can be used for generating electricity for the same applications as many other means of generation, they really come into their own where disadvantages associated with an intermittent unpredictable supply are not severe. The paper discusses the advantages and disadvantages to be taken into account when considering a photovoltaic power system. Five main applications, based on the system features, are listed and explained. They are: consumer, professional, rural electrification, building-integrated, centralised grid connected and space power. A brief history of the applications of photovoltaics is presented with statistical data on the growth of installed capacity since 1992. The developing market for photovoltaics is discussed together with how environmental issues have become a driver for development of building-integrated photovoltaics

Mathematical modeling of photovoltaic thermal PV/T system with v-groove collector

Science.gov (United States)

Zohri, M.; Fudholi, A.; Ruslan, M. H.; Sopian, K.

2017-07-01

The use of v-groove in solar collector has a higher thermal efficiency in references. Dropping the working heat of photovoltaic panel was able to raise the electrical efficiency performance. Electrical and thermal efficiency were produced by photovoltaic thermal (PV/T) system concurrently. Mathematical modeling based on steady-state thermal analysis of PV/T system with v-groove was conducted. With matrix inversion method, the energy balance equations are explained by means of the investigative method. The comparison results show that in the PV/T system with the V-groove collector is higher temperature, thermal and electrical efficiency than other collectors.

Combining CFD simulations with blockoriented heatflow-network model for prediction of photovoltaic energy-production

International Nuclear Information System (INIS)

Haber, I E; Farkas, I

2011-01-01

The exterior factors which influencing the working circumstances of photovoltaic modules are the irradiation, the optical air layer (Air Mass - AM), the irradiation angle, the environmental temperature and the cooling effect of the wind. The efficiency of photovoltaic (PV) devices is inversely proportional to the cell temperature and therefore the mounting of the PV modules can have a big affect on the cooling, due to wind flow-around and naturally convection. The construction of the modules could be described by a heatflow-network model, and that can define the equation which determines the cells temperature. An equation like this can be solved as a block oriented model with hybrid-analogue simulator such as Matlab-Simulink. In view of the flow field and the heat transfer, witch was calculated numerically, the heat transfer coefficients can be determined. Five inflow rates were set up for both pitched and flat roof cases, to let the trend of the heat transfer coefficient know, while these functions can be used for the Matlab/Simulink model. To model the free convection flows, the Boussinesq-approximation were used, integrated into the Navier-Stokes equations and the energy equation. It has been found that under a constant solar heat gain, the air velocity around the modules and behind the pitched-roof mounted module is increasing, proportionately to the wind velocities, and as result the heat transfer coefficient increases linearly, and can be described by a function in both cases. To the block based model the meteorological parameters and the results of the CFD simulations as single functions were attached. The final aim was to make a model that could be used for planning photovoltaic systems, and define their accurate performance for better sizing of an array of modules.

A Decision Model for Choosing Among Photovoltaic Technologies to Generate Electricity at Grid-Connected Air Force Facilities: A Value-Focused Approach

Science.gov (United States)

2006-03-01

goals, but it is also carries significant political interest. 1.1.4. Photovoltaic Effect A monocrystalline silicon photovoltaic cell (Figure 2) is...developed the industry by creating small photovoltaic panels to power watches and calculators (Archer, 2001; Wronski and Carlson, 2001). Amorphous silicon...Clinton, 1999). One particularly promising renewable energy source is solar energy converted to electricity by solar photovoltaic panels . Previous

Small-Scale Combined Heat and Power Plants Using Biofuels

Energy Technology Data Exchange (ETDEWEB)

Salomon-Popa, Marianne [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

2002-11-01

In this time period where energy supply and climate change are of special concern, biomass-based fuels have attracted much interest due to their plentiful supply and favorable environmental characteristics (if properly managed). The effective capture and continued sustainability of this renewable resource requires a new generation of biomass power plants with high fuel energy conversion. At the same time, deregulation of the electricity market offers new opportunities for small-scale power plants in a decentralized scheme. These two important factors have opened up possibilities for small-scale combined heat and power (CHP) plants based on biofuels. The objective of this pre-study is to assess the possibilities and technical limitations for increased efficiency and energy utilization of biofuels in small size plants (approximately 10 MWe or lower). Various energy conversion technologies are considered and proven concepts for large-scale fossil fuel plants are an especially important area. An analysis has been made to identify the problems, technical limitations and different possibilities as recognized in the literature. Beyond published results, a qualitative survey was conducted to gain first-hand, current knowledge from experts in the field. At best, the survey results together with the results of personal interviews and a workshop on the role of small-scale plants in distributed generation will serve a guideline for future project directions and ideas. Conventional and novel technologies are included in the survey such as Stirling engines, combustion engines, gas turbines, steam turbines, steam motors, fuel cells and other novel technologies/cycles for biofuels. State-of-the-art heat and power plants will be identified to clarify of the advantages and disadvantages as well as possible obstacles for their implementation.

Customized color patterning of photovoltaic cells

Science.gov (United States)

Cruz-Campa, Jose Luis; Nielson, Gregory N.; Okandan, Murat; Lentine, Anthony L.; Resnick, Paul J.; Gupta, Vipin P.

2016-11-15

Photovoltaic cells and photovoltaic modules, as well as methods of making and using such photovoltaic cells and photovoltaic modules, are disclosed. More particularly, embodiments of the photovoltaic cells selectively reflect visible light to provide the photovoltaic cells with a colorized appearance. Photovoltaic modules combining colorized photovoltaic cells may be used to harvest solar energy while providing a customized appearance, e.g., an image or pattern.

Economics of Future Growth in Photovoltaics Manufacturing

Energy Technology Data Exchange (ETDEWEB)

Basore, Paul A.; Chung, Donald; Buonassisi, Tonio

2015-06-14

The past decade's record of growth in the photovoltaics manufacturing industry indicates that global investment in manufacturing capacity for photovoltaic modules tends to increase in proportion to the size of the industry. The slope of this proportionality determines how fast the industry will grow in the future. Two key parameters determine this slope. One is the annual global investment in manufacturing capacity normalized to the manufacturing capacity for the previous year (capacity-normalized capital investment rate, CapIR, units $/W). The other is how much capital investment is required for each watt of annual manufacturing capacity, normalized to the service life of the assets (capacity-normalized capital demand rate, CapDR, units $/W). If these two parameters remain unchanged from the values they have held for the past few years, global manufacturing capacity will peak in the next few years and then decline. However, it only takes a small improvement in CapIR to ensure future growth in photovoltaics. Any accompanying improvement in CapDR will accelerate that growth.

Energy and Cost Saving of a Photovoltaic-Phase Change Materials (PV-PCM System through Temperature Regulation and Performance Enhancement of Photovoltaics

Directory of Open Access Journals (Sweden)

Ahmad Hasan

2014-03-01

Full Text Available The current research seeks to maintain high photovoltaic (PV efficiency and increased operating PV life by maintaining them at a lower temperature. Solid-liquid phase change materials (PCM are integrated into PV panels to absorb excess heat by latent heat absorption mechanism and regulate PV temperature. Electrical and thermal energy efficiency analysis of PV-PCM systems is conducted to evaluate their effectiveness in two different climates. Finally costs incurred due to inclusion of PCM into PV system and the resulting benefits are discussed in this paper. The results show that such systems are financially viable in higher temperature and higher solar radiation environment.

High-Efficiency Small-Scale Combined Heat and Power Organic Binary Rankine Cycles

Directory of Open Access Journals (Sweden)

Costante Mario Invernizzi

2018-04-01

Full Text Available Small-CHP (Combined Heat and Power systems are generally considered a valuable technological option to the conventional boilers, in a technology developed context. If small-CHP systems are associated with the use of renewable energies (biomass, for example they could play an important role in distributed generation even in developing countries or, in any case, where there are no extensive electricity networks. Traditionally the considered heat engines for micro- or mini-CHP are: the gas engine, the gas turbine (with internal combustion, the steam engine, engine working according to the Stirling and to the Rankine cycles, the last with organic fluids. In principle, also fuel cells could be used. In this paper, we focus on small size Rankine cycles (10–15 k W with organic working fluids. The assumed heat source is hot combustion gases at high temperature (900–950 ∘ C and we assume to use only single stages axial turbines. The need to work at high temperatures, limits the choice of the right organic working fluids. The calculation results show the limitation in the performances of simple cycles and suggest the opportunity to resort to complex (binary cycle configurations to achieve high net conversion efficiencies (15–16%.

Engineering a Grid-Tied Residential Photovoltaic System: A Student Activity

Science.gov (United States)

Litowitz, Len S.

2012-01-01

Photovoltaics is a term that refers to thin cells that have the ability to directly convert sunlight into electricity. This process occurs without the use of any moving parts, and the sunlight is free for the taking if it can be captured for useful purposes like heating water or air or producing electricity. As the cost of installing a…

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.

Optical refrigeration for ultra-efficient photovoltaics

Science.gov (United States)

Manor, Assaf; Martin, Leopoldo L.; Rotschild, Carmel

2015-03-01

The Shockley-Queisser (SQ) efficiency limit for single-junction photovoltaic cell (PV) is to a great extent due to inherent heat dissipation accompanying the quantum process of electro-chemical potential generation. Concepts such as solar thermophotovoltaics1,2,3 (STPV) and thermo-photonics4 aim to harness this dissipated heat, claiming very high theoretical limit. In practice, none of these concepts have been experimentally proven to overcome the SQ limit, mainly due to the very high operating temperatures, which significantly challenge electro-optical devices. In contrast to the above concepts for harnessing thermal emission at thermal equilibrium, Photoluminescence (PL) is a fundamental light-matter interaction under non-thermal equilibrium, which conventionally involves the absorption of energetic photon, thermalization and the emission of a red-shifted photon. Conversely, in optical-refrigeration the absorption of low energy photon is followed by endothermic-PL of energetic photon5,6. Both aspects were mainly studied where thermal population is far weaker than photonic excitation, obscuring the generalization of PL and thermal emissions. Here we experimentally study endothermic-PL at high temperatures7. In accordance with theory, we show how PL photon rate is conserved with temperature increase, while each photon is blue shifted. Further rise in temperature leads to an abrupt transition to thermal emission where the photon rate increases sharply. We also show how endothermic-PL generates orders of magnitude more energetic photons than thermal emission at similar temperatures. Relying on these observations, we propose and study thermally enhanced PL (TEPL) for highly efficient solar-energy conversion. Here, solar radiation is absorbed by a low-bandgap PL material. The dissipated heat is emitted by endothermic PL, and harvested by a higher-bandgap photovoltaic cell. While such device operates at much lower temperatures than STPV, the theoretical efficiencies

Magnetic properties of atmospheric PMx in a small settlement during heating and non-heating season

Science.gov (United States)

Petrovsky, E.; Kotlik, B.; Zboril, R.; Kapicka, A.; Grison, H.

2012-04-01

Magnetic properties of environmental samples can serve as fast and relatively cheap proxy method to investigate occurrence of iron oxides. These methods are very sensitive in detecting strongly magnetic compounds such as magnetite and maghemite and can reveal concentration and assess grain-size distribution of these minerals. This information can be significant in estimating e.g. the source of pollutants, monitoring pollution load, or investigating seasonal and climatic effects. We studied magnetic properties of PM1, PM2.5 and PM10, collected over 32-48 hours in a small settlement in south Bohemia during heating and non-heating season. The site is rather remote, with negligible traffic and industrial contributions to air pollution. Thus, the suggested seasonal effect should be dominantly due to local (domestic) heating, burning wood or coal. In our contribution we show typical differences in PMx concentration, which is much higher in the winter (heating) sample, accompanied by SEM analyses and magnetic data oriented on concentration and grain-size distribution of magnetite/maghemite particles. While concentration of Fe-oxides does not vary that much, significant seasonal differences were observed in composition and grain-size distribution, reflecting different sources of the dust particles.

Experimental study and performance analysis of a thermoelectric cooling and heating system driven by a photovoltaic/thermal system in summer and winter operation modes

International Nuclear Information System (INIS)

He, Wei; Zhou, JinZhi; Chen, Chi; Ji, Jie

2014-01-01

Highlights: • Thermoelectric heating system driven by heat pipe PV/T system was built and test. • Theoretical analysis has been done and simulation results have been validated by experiments. • The energetic efficiency and exergetic efficiency in summer and winter operation mode was analyzed and compared. - Abstract: This paper presents theoretical and experimental investigations of the winter operation mode of a thermoelectric cooling and heating system driven by a heat pipe photovoltaic/thermal (PV/T) panel. And the energy and exergy analysis of this system in summer and winter operation modes are also done. The winter operation mode of this system is tested in an experimental room which temperature is controlled at 18 °C. The results indicate the average coefficient of performance (COP) of thermoelectric module of this system can be about 1.7, the electrical efficiency of the PV/T panel can reach 16.7%, and the thermal efficiency of this system can reach 23.5%. The energy and exergy analysis show the energetic efficiency of the system in summer operation mode is higher than that of it in winter operation mode, but the exergetic efficiency in summer operation mode is lower than that in winter operation mode, on the contrary

The keys to success in marketing small heating reactors

International Nuclear Information System (INIS)

McDougall, D.S.; Lynch, G.F.

1988-01-01

The success of the SLOWPOKE Energy System requires acceptance of the SLOWPOKE reactor within the community where the reactor's energy is to be used. Public acceptance will be obtained once the public is convinced that this nuclear heat source is needed, safe and of economic benefit to the community. The need for a new application of nuclear energy is described and the ability of small reactors used for district heating to play that role is shown. The safety of the reactor is being demonstrated with the establishment of the SLOWPOKE Demonstration Reactor by Atomic Energy of Canada Limited and with open, candid discussion with the involved community. Economic arguments are reviewed and include discussion of quantitative and qualitative issues. (orig.)

Photovoltaic energy barometer

International Nuclear Information System (INIS)

Anon.

2007-01-01

The european photovoltaic market once again reached the heights in 2006, thanks to the dynamism of the German market. White paper objectives have thus been fulfilled four years ahead of schedule. The european photovoltaic sector remains however very heterogeneous with both an ultra-dominant German market (estimated at 1150 MWp in 2006) and other countries of the European Union that vary from a few kWP to a few dozen MWp. This analysis provides statistical data on the market, the capacity installed during 2005 and 2006, the photovoltaic parks and the evolution of the photovoltaic cell production. (A.L.B.)

Performance of Polycrystalline Photovoltaic and Thermal Collector (PVT on Serpentine-Parallel Absor

Directory of Open Access Journals (Sweden)

Mustofa

2015-10-01

Full Text Available This paper presents the performance of an unglazed polycrystalline photovoltaic-thermal PVT on 0.045 kg/s mass flow rate. PVT combine photovoltaic modules and solar thermal collectors, forming a single device that receive solar radiation and produces heat and electricity simultaneously. The collector figures out serpentine-parallel tubes that can prolong fluid heat conductivity from morning till afternoon. During testing, cell PV, inlet and outlet fluid temperatures were recorded by thermocouple digital LM35 Arduino Mega 2560. Panel voltage and electric current were also noted in which they were connected to computer and presented each second data recorded. But, in this performance only shows in the certain significant time data. This because the electric current was only noted by multimeter device not the digital one. Based on these testing data, average cell efficiency was about 19%, while thermal efficiency of above 50% and correspondent cell efficiency of 11%, respectively.

Citywide Impacts of Cool Roof and Rooftop Solar Photovoltaic Deployment on Near-Surface Air Temperature and Cooling Energy Demand

Science.gov (United States)

Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Martilli, A.

2016-10-01

Assessment of mitigation strategies that combat global warming, urban heat islands (UHIs), and urban energy demand can be crucial for urban planners and energy providers, especially for hot, semi-arid urban environments where summertime cooling demands are excessive. Within this context, summertime regional impacts of cool roof and rooftop solar photovoltaic deployment on near-surface air temperature and cooling energy demand are examined for the two major USA cities of Arizona: Phoenix and Tucson. A detailed physics-based parametrization of solar photovoltaic panels is developed and implemented in a multilayer building energy model that is fully coupled to the Weather Research and Forecasting mesoscale numerical model. We conduct a suite of sensitivity experiments (with different coverage rates of cool roof and rooftop solar photovoltaic deployment) for a 10-day clear-sky extreme heat period over the Phoenix and Tucson metropolitan areas at high spatial resolution (1-km horizontal grid spacing). Results show that deployment of cool roofs and rooftop solar photovoltaic panels reduce near-surface air temperature across the diurnal cycle and decrease daily citywide cooling energy demand. During the day, cool roofs are more effective at cooling than rooftop solar photovoltaic systems, but during the night, solar panels are more efficient at reducing the UHI effect. For the maximum coverage rate deployment, cool roofs reduced daily citywide cooling energy demand by 13-14 %, while rooftop solar photovoltaic panels by 8-11 % (without considering the additional savings derived from their electricity production). The results presented here demonstrate that deployment of both roofing technologies have multiple benefits for the urban environment, while solar photovoltaic panels add additional value because they reduce the dependence on fossil fuel consumption for electricity generation.

Thermionic photovoltaic energy converter

Science.gov (United States)

Chubb, D. L. (Inventor)

1985-01-01

A thermionic photovoltaic energy conversion device comprises a thermionic diode mounted within a hollow tubular photovoltaic converter. The thermionic diode maintains a cesium discharge for producing excited atoms that emit line radiation in the wavelength region of 850 nm to 890 nm. The photovoltaic converter is a silicon or gallium arsenide photovoltaic cell having bandgap energies in this same wavelength region for optimum cell efficiency.

An active cooling system for photovoltaic modules

International Nuclear Information System (INIS)

Teo, H.G.; Lee, P.S.; Hawlader, M.N.A.

2012-01-01

The electrical efficiency of photovoltaic (PV) cell is adversely affected by the significant increase of cell operating temperature during absorption of solar radiation. A hybrid photovoltaic/thermal (PV/T) solar system was designed, fabricated and experimentally investigated in this work. To actively cool the PV cells, a parallel array of ducts with inlet/outlet manifold designed for uniform airflow distribution was attached to the back of the PV panel. Experiments were performed with and without active cooling. A linear trend between the efficiency and temperature was found. Without active cooling, the temperature of the module was high and solar cells can only achieve an efficiency of 8–9%. However, when the module was operated under active cooling condition, the temperature dropped significantly leading to an increase in efficiency of solar cells to between 12% and 14%. A heat transfer simulation model was developed to compare to the actual temperature profile of PV module and good agreement between the simulation and experimental results is obtained.

Parallel experimental study of a novel super-thin thermal absorber based photovoltaic/thermal (PV/T system against conventional photovoltaic (PV system

Directory of Open Access Journals (Sweden)

Peng Xu

2015-11-01

Full Text Available Photovoltaic (PV semiconductor degrades in performance due to temperature rise. A super thin-conductive thermal absorber is therefore developed to regulate the PV working temperature by retrofitting the existing PV panel into the photovoltaic/thermal (PV/T panel. This article presented the parallel comparative investigation of the two different systems through both laboratory and field experiments. The laboratory evaluation consisted of one PV panel and one PV/T panel respectively while the overall field system involved 15 stand-alone PV panels and 15 retrofitted PV/T panels. The laboratory testing results demonstrated the PV/T panel could achieve the electrical efficiency of about 16.8% (relatively 5% improvement comparing with the stand-alone PV panel, and yield an extra amount of heat with thermal efficiency of nearly 65%. The field testing results indicated that the hybrid PV/T panel could enhance the electrical return of PV panels by nearly 3.5%, and increase the overall energy output by nearly 324.3%. Further opportunities and challenges were then discussed from aspects of different PV/T stakeholders to accelerate the development. It is expected that such technology could become a significant solution to yield more electricity, offset heating load freely and reduce carbon footprint in contemporary energy environment.

Temperature and color management of silicon solar cells for building integrated photovoltaic

Science.gov (United States)

Amara, Mohamed; Mandorlo, Fabien; Couderc, Romain; Gerenton, Félix; Lemiti, Mustapha

2018-01-01

Color management of integrated photovoltaics must meet two criteria of performance: provide maximum conversion efficiency and allow getting the chosen colors with an appropriate brightness, more particularly when using side by side solar cells of different colors. As the cooling conditions are not necessarily optimal, we need to take into account the influence of the heat transfer and temperature. In this article, we focus on the color space and brightness achieved by varying the antireflective properties of flat silicon solar cells. We demonstrate that taking into account the thermal effects allows freely choosing the color and adapting the brightness with a small impact on the conversion efficiency, except for dark blue solar cells. This behavior is especially true when heat exchange by convection is low. Our optical simulations show that the perceived color, for single layer ARC, is not varying with the position of the observer, whatever the chosen color. The use of a double layer ARC adds flexibility to tune the wanted color since the color space is greatly increased in the green and yellow directions. Last, choosing the accurate material allows both bright colors and high conversion efficiency at the same time.

Temperature and color management of silicon solar cells for building integrated photovoltaic

Directory of Open Access Journals (Sweden)

Amara Mohamed

2018-01-01

Full Text Available Color management of integrated photovoltaics must meet two criteria of performance: provide maximum conversion efficiency and allow getting the chosen colors with an appropriate brightness, more particularly when using side by side solar cells of different colors. As the cooling conditions are not necessarily optimal, we need to take into account the influence of the heat transfer and temperature. In this article, we focus on the color space and brightness achieved by varying the antireflective properties of flat silicon solar cells. We demonstrate that taking into account the thermal effects allows freely choosing the color and adapting the brightness with a small impact on the conversion efficiency, except for dark blue solar cells. This behavior is especially true when heat exchange by convection is low. Our optical simulations show that the perceived color, for single layer ARC, is not varying with the position of the observer, whatever the chosen color. The use of a double layer ARC adds flexibility to tune the wanted color since the color space is greatly increased in the green and yellow directions. Last, choosing the accurate material allows both bright colors and high conversion efficiency at the same time.

Guiding principle for crystalline Si photovoltaic modules with high tolerance to acetic acid

Science.gov (United States)

Masuda, Atsushi; Hara, Yukiko

2018-04-01

A guiding principle for highly reliable crystalline Si photovoltaic modules, especially those with high tolerance to acetic acid generated by hydrolysis reaction between water vapor and an ethylene-vinyl acetate (EVA) encapsulant, is proposed. Degradation behavior evaluated by the damp heat test strongly depends on Ag finger electrodes and also EVA encapsulants. The acetic acid concentration in EVA on the glass side directly determines the degradation behavior. The most important factor for high tolerance is the type of Ag finger electrode materials when using an EVA encapsulant. Photovoltaic modules using newly developed crystalline Si cells with improved Ag finger electrode materials keep their maximum power of 80% of the initial value even after the damp heat test at 85 °C and 85% relative humidity for 10000 h. The pattern of dark regions in electroluminescence images is also discussed on the basis of the dynamics of acetic acid in the modules.

Transparent ultraviolet photovoltaic cells.

Science.gov (United States)

Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

2016-02-15

Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future.

Influence of the replacement of alkoxyl with alkylthienyl on photovoltaic properties of two small molecule donors for organic solar cells

Institute of Scientific and Technical Information of China (English)

Shaoqing Zhang; Liyan Yang; Delong Liu; Chang He; Jianqi Zhang; Yun Zhang; Jianhui Hou

2017-01-01

Two benzo[1,2-b:4,5-b']dithiophene (BDT)-based small molecule (SM) donor materials with identical conjugated backbones but different substitution groups,named as DRTB-O and DRTB-T,were well explored to demonstrate the influence of the replacement of alkoxy with alkylthienyl on their photovoltaic properties in fullerene-based and fullerene-free organic solar cells (OSCs).The study shows that the two SM donors possess similar absorption spectra and energy levels but different crystalline structures in solid films.The carrier transport property and phase separation morphologies of the blend films have also been fully investigated.By employing PC71BM as the acceptor,the power conversion efficiency (PCE) of DRTB-O:PC71BM and DRTB-T:PC71BM based devices were 4.91％ and 7.08％,respectively.However,by blending with IDIC,the two SM donors exhibited distinctly different photovoltaic properties in fullerene-free OSCs,and the PCE of DRTB-O:IDIC and DRTB-T:IDIC based devices were 0.15％ and 9.06％,respectively.These results indicate that the replacement of alkoxyl with alkylthienyl in designing SM donor materials plays an important role in the application of fullerene-free OSCs.

Three-phase Photovoltaic Systems

DEFF Research Database (Denmark)

Kerekes, Tamas; Sera, Dezso; Máthé, Lászlo

2015-01-01

, detailing the different photovoltaic inverter structures and topologies as well as discussing the different control layers within a grid-connected photovoltaic plant. Modulation schemes for various photovoltaic inverter topologies, grid synchronization, current control, active and reactive power control......Photovoltaic technology has experienced unprecedented growth in the last two decades, transforming from mainly off-grid niche generation to a major renewable energy technology, reaching approximately 180 GW of capacity worldwide at the end of 2014. Large photovoltaic power plants interfacing...... the grid through a three-phase power electronic converter are now well on the way to becoming a major player in the power system in many countries. Therefore, this article gives an overview of photovoltaic systems with a focus on three-phase applications, presenting these both from a hardware point of view...

A detailed thermal-electrical model of three photovoltaic/thermal (PV/T) hybrid air collectors and photovoltaic (PV) module: Comparative study under Algiers climatic conditions

International Nuclear Information System (INIS)

Slimani, Mohamed El Amine; Amirat, Madjid; Kurucz, Ildikó; Bahria, Sofiane; Hamidat, Abderrahmane; Chaouch, Wafa Braham

2017-01-01

Highlights: • A detailed thermal and electrical model for PV and PV/T systems has been presented. • The developed numerical model was validated successfully with previously published experimental results. • A comparative study between four solar devices (PV and PV/T systems) was carried out. • The experimental weather conditions of Algiers site are used in the numerical model. • The glazed double-pass photovoltaic/thermal air collector shows the best overall energy efficiency. - Abstract: The thermal photovoltaic hybrid collector is a genuine cogeneration technology; it can produce electricity and heat simultaneously. In this paper, a comparative study is presented between four solar device configurations: photovoltaic module (PV-I), conventional hybrid solar air collector (PV/T-II), glazed hybrid solar air collector (PV/T-III) and glazed double-pass hybrid solar air collector (PV/T-IV). A numerical model is developed and validated through experimental results indicated in the previous literature. The numerical model takes the heat balance equations and different thermal and electrical parameters into account for each configuration included in this study, the energy performances are evaluated with a sample weather data of Algiers site. The numerical results show that the daily average of overall energy efficiency reaches: 29.63%, 51.02%, 69.47% and 74% for the first (PV-I), the second (PV/T-II), the third (PV/T-III) and the fourth (PV/T-IV) configurations respectively. These values are obtained with an air flow of 0.023 kg/s and introducing a sample of experimental weather data collected in Algiers site for a sunny day in summer.

Pronounced Photovoltaic Response from Multilayered Transition-Metal Dichalcogenides PN-Junctions.

Science.gov (United States)

Memaran, Shahriar; Pradhan, Nihar R; Lu, Zhengguang; Rhodes, Daniel; Ludwig, Jonathan; Zhou, Qiong; Ogunsolu, Omotola; Ajayan, Pulickel M; Smirnov, Dmitry; Fernández-Domínguez, Antonio I; García-Vidal, Francisco J; Balicas, Luis

2015-11-11

Transition metal dichalcogenides (TMDs) are layered semiconductors with indirect band gaps comparable to Si. These compounds can be grown in large area, while their gap(s) can be tuned by changing their chemical composition or by applying a gate voltage. The experimental evidence collected so far points toward a strong interaction with light, which contrasts with the small photovoltaic efficiencies η ≤ 1% extracted from bulk crystals or exfoliated monolayers. Here, we evaluate the potential of these compounds by studying the photovoltaic response of electrostatically generated PN-junctions composed of approximately 10 atomic layers of MoSe2 stacked onto the dielectric h-BN. In addition to ideal diode-like response, we find that these junctions can yield, under AM-1.5 illumination, photovoltaic efficiencies η exceeding 14%, with fill factors of ~70%. Given the available strategies for increasing η such as gap tuning, improving the quality of the electrical contacts, or the fabrication of tandem cells, our study suggests a remarkable potential for photovoltaic applications based on TMDs.

Design of a holographic micro-scale spectrum-splitting photovoltaic system

Science.gov (United States)

Wu, Yuechen; Vorndran, Shelby; Ayala Pelaez, Silvana; Russo, Juan M.; Kostuk, Raymond K.

2015-09-01

Micro-scale PV technology combines the high conversion efficiency of concentrated photovoltaics (CPV) with the low costs and the simple form of flat panel PV. Some of the benefits of micro-scale PV include: reduced semiconductor material usage; improved heat rejection capacity; and more versatile PV cell interconnect configurations. Spectrumsplitting is also a beneficial technique to increase the efficiency and reduce the cost of photovoltaic systems. It spatially separates the incident solar spectrum into spectral components and directs them to PV cells with matching bandgaps. This approach avoids the current and lattice matching problems that exist in tandem multi-junction systems. In this paper, we applied the ideas of spectrum-splitting in a micro-scale PV system, and demonstrated a holographic micro-scale spectrum-splitting photovoltaic system. This system consists of a volume transmission hologram in combination with a micro-lens array. An analysis methodology was developed to design the system and determine the performance of the resulting system. The spatial characteristics of the dispersed spectrum, the overall system conversion efficiency, and the improvement over best bandgap will be discussed.

High-Penetration Photovoltaic Planning Methodologies

Energy Technology Data Exchange (ETDEWEB)

Gao, David Wenzhong [Alternative Power Innovations, LLC, Broomfield, CO (United States); Muljadi, Eduard [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Mackay [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-02-24

The main objective of this report is to provide an overview of select U.S. utility methodologies for performing high-penetration photovoltaic (HPPV) system planning and impact studies. This report covers the Federal Energy Regulatory Commission's orders related to photovoltaic (PV) power system interconnection, particularly the interconnection processes for the Large Generation Interconnection Procedures and Small Generation Interconnection Procedures. In addition, it includes U.S. state interconnection standards and procedures. The procedures used by these regulatory bodies consider the impacts of HPPV power plants on the networks. Technical interconnection requirements for HPPV voltage regulation include aspects of power monitoring, grounding, synchronization, connection to the overall distribution system, back-feeds, disconnecting means, abnormal operating conditions, and power quality. This report provides a summary of mitigation strategies to minimize the impact of HPPV. Recommendations and revisions to the standards may take place as the penetration level of renewables on the grid increases and new technologies develop in future years.

Light Harvesting for Organic Photovoltaics

Science.gov (United States)

2016-01-01

The field of organic photovoltaics has developed rapidly over the last 2 decades, and small solar cells with power conversion efficiencies of 13% have been demonstrated. Light absorbed in the organic layers forms tightly bound excitons that are split into free electrons and holes using heterojunctions of electron donor and acceptor materials, which are then extracted at electrodes to give useful electrical power. This review gives a concise description of the fundamental processes in photovoltaic devices, with the main emphasis on the characterization of energy transfer and its role in dictating device architecture, including multilayer planar heterojunctions, and on the factors that impact free carrier generation from dissociated excitons. We briefly discuss harvesting of triplet excitons, which now attracts substantial interest when used in conjunction with singlet fission. Finally, we introduce the techniques used by researchers for characterization and engineering of bulk heterojunctions to realize large photocurrents, and examine the formed morphology in three prototypical blends. PMID:27951633

The experimental study of a two-stage photovoltaic thermal system based on solar trough concentration

International Nuclear Information System (INIS)

Tan, Lijun; Ji, Xu; Li, Ming; Leng, Congbin; Luo, Xi; Li, Haili

2014-01-01

Highlights: • A two-stage photovoltaic thermal system based on solar trough concentration. • Maximum cell efficiency of 5.21% with the mirror opening width of 57 cm. • With single cycle, maximum temperatures rise in the heating stage is 12.06 °C. • With 30 min multiple cycles, working medium temperature 62.8 °C, increased 28.7 °C. - Abstract: A two-stage photovoltaic thermal system based on solar trough concentration is proposed, in which the metal cavity heating stage is added on the basis of the PV/T stage, and thermal energy with higher temperature is output while electric energy is output. With the 1.8 m 2 mirror PV/T system, the characteristic parameters of the space solar cell under non-concentrating solar radiation and concentrating solar radiation are respectively tested experimentally, and the solar cell output characteristics at different opening widths of concentrating mirror of the PV/T stage under condensation are also tested experimentally. When the mirror opening width was 57 cm, the solar cell efficiency reached maximum value of 5.21%. The experimental platform of the two-stage photovoltaic thermal system was established, with a 1.8 m 2 mirror PV/T stage and a 15 m 2 mirror heating stage, or a 1.8 m 2 mirror PV/T stage and a 30 m 2 mirror heating stage. The results showed that with single cycle, the long metal cavity heating stage would bring lower thermal efficiency, but temperature rise of the working medium is higher, up to 12.06 °C with only single cycle. With 30 min closed multiple cycles, the temperature of the working medium in the water tank was 62.8 °C, with an increase of 28.7 °C, and thermal energy with higher temperature could be output

Flexo-photovoltaic effect.

Science.gov (United States)

Yang, Ming-Min; Kim, Dong Jik; Alexe, Marin

2018-04-19

It is highly desirable to discover photovoltaic mechanisms that enable a higher efficiency of solar cells. Here, we report that the bulk photovoltaic effect, which is free from the thermodynamic Shockley-Queisser limit but usually manifested only in noncentrosymmetric (piezoelectric or ferroelectric) materials, can be realized in any semiconductor, including silicon, by mediation of flexoelectric effect. We introduce strain gradients using either an atomic force microscope or a micron-scale indentation system, creating giant photovoltaic currents from centrosymmetric single crystals of SrTiO 3 , TiO 2 , and Si. This strain-gradient-induced bulk photovoltaic effect, which we call the flexo-photovoltaic effect, functions in the absence of a p - n junction. This finding may extend present solar cell technologies by boosting the solar energy conversion efficiency from a wide pool of established semiconductors. Copyright © 2018, American Association for the Advancement of Science.

Fuzzy Logic System for Intermixed Biogas and Photovoltaics Measurement and Control

Directory of Open Access Journals (Sweden)

Liston Matindife

2018-01-01

Full Text Available This study develops a new integrated measurement and control system for intermixed biogas and photovoltaic systems to achieve safe and optimal energy usage. Literature and field studies show that existing control methods on small- to medium-scale systems fall short of comprehensive system optimization and fault diagnosis, hence the need to revisit these control methods. The control strategy developed in this study is intelligent as it is wholly based on fuzzy logic algorithms. Fuzzy logic controllers due to their superior nonlinear problem solving capabilities to classical controllers considerably simplify controller design. The mathematical models that define classical controllers are difficult or impossible to realize in biogas and photovoltaic generation process. A microcontroller centered fuzzy logic measurement and control embedded system is designed and developed on the existing hybrid biogas and photovoltaic installations. The designed system is able to accurately predict digester stability, quantify biogas output, and carry out biogas fault detection and control. Optimized battery charging and photovoltaic fault detection and control are also successfully implemented. The system is able to optimize the operation and performance of biogas and photovoltaic energy generation.

Experiment and Simulation Study on the Amorphous Silicon Photovoltaic Walls

Directory of Open Access Journals (Sweden)

Wenjie Zhang

2014-01-01

Full Text Available Based on comparative study on two amorphous silicon photovoltaic walls (a-Si PV walls, the temperature distribution and the instant power were tested; and with EnergyPlus software, similar models of the walls were built to simulate annual power generation and air conditioning load. On typical sunshine day, the corresponding position temperature of nonventilated PV wall was generally 0.5~1.5°C higher than that of ventilated one, while the power generation was 0.2%~0.4% lower, which was consistent with the simulation results with a difference of 0.41% in annual energy output. As simulation results, in summer, comparing the PV walls with normal wall, the heat per unit area of these two photovoltaic walls was 5.25 kWh/m2 (nonventilated and 0.67 kWh/m2 (ventilated higher, respectively. But in winter the heat loss of nonventilated one was smaller, while ventilated PV wall was similar to normal wall. To annual energy consumption of heating and cooling, the building with ventilated PV wall and normal wall was also similar but slightly better than nonventilated one. Therefore, it is inferred that, at low latitudes, such as Zhuhai, China, air gap ventilation is suitable, while the length to thickness ratio of the air gap needs to be taken into account.

Photovoltaic cell

Science.gov (United States)

Gordon, Roy G.; Kurtz, Sarah

1984-11-27

In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

Photovoltaic device

DEFF Research Database (Denmark)

2011-01-01

A photovoltaic cell module including a plurality of serially connected photovoltaic cells on a common substrate, each including a first electrode, a printed light-harvesting layer and a printed second electrode, wherein at least one of the electrodes is transparent, and wherein the second electrode...... of a first cell is printed such that it forms an electrical contact with the first electrode of an adjacent second cell without forming an electrical contact with the first electrode of the first cell or the light-harvesting layer of the second cell, and a method of making such photovoltaic cell modules....

Siting analysis and risk assessment for small single-purpose heating reactors

International Nuclear Information System (INIS)

Tarjanne, R.

1979-04-01

Two alternative sites both 10km away from the centre of Helsinki are considered for reactor unit sizes of 400mw and 800mw. The risks associated with a small single-purpose heating reactor is evaluated for normal operation and accident conditions. The evaluation for accident condition is performed for three characteristics accidents. Three pathways are considered in the calculation of the radiation exposure: direct external gamma dose from the release plume, direct gamma radiation from deposited activity on the ground and dose due to inhalation. The risks are compared with the risks from alternative conventional fossil fuelled district heat production methods. The results show that the heating reactor alternative causes an unsignificant risk, which is far less than the risk caused by the fossil-fuelled alternatives

Performance investigation of a concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator

International Nuclear Information System (INIS)

Feng, Chaoqing; Zheng, Hongfei; Wang, Rui; Ma, Xinglong

2016-01-01

Highlights: • A common design method of a cycloidal transmissive Fresnel solar concentrator was presented. • The gallium arsenide high concentrated solar was used as the receiver. • High efficiency of electric generating could be achieved at noon. • Fresnel solar concentrator was studied and compared in hazy weather and clear weather. - Abstract: A design method of a cycloidal transmissive Fresnel solar concentrator which can provide a certain width focal line was presented in this study. Based on the optical principle of refraction, the dimensions of each wedge-shaped element of Fresnel lens are calculated. An optical simulation has been done to obtain the optical efficiency of the concentrator for different tracking error and axial incidence angle. It has been found that about 80% of the incident sunlight can still be gathered by the absorber when the tracking error is within 0.7°. When the axial angle of incidence is within 10°, it almost has no influence to the receiving rate. The concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator has been designed in this paper. Take the gallium arsenide high concentrated battery as the receiver, experimental research about cylindrical Fresnel concentrating photovoltaic/thermal system is undertaken in the real sky. Main parameters are tested such as the temperature distribution on receiver, electric energy and thermal energy outputs of concentrating photovoltaic/thermal system, the efficiency of multipurpose utilization of electric and heat, and so on. The test results in clear weather show that maximum electric generating efficiency is about 18% at noon, the maximum heat receiving rate of cooling water is about 45%. At noon time (11:00–13:00), the total efficiency of thermal and electricity can reach more than 55%. Performance of this concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator is studied and compared in two types typical weather, hazy

Safety characteristics of small heat producing reactors

International Nuclear Information System (INIS)

Seifritz, W.

1987-10-01

The primary objectives of protection in nuclear power plants are the possibility to shut the reactor down in case of emergency and keep it subcritical in the long run, the existence of a heat sink for post-decay heat removal in order to avoid overheating, let alone core meltdown, and the containment of radioactivity within the barriers designed for this purpose, thus preventing significant activity release. In principle, these objectives can be met in various ways, namely by active, passive or inherent technical safeguards systems. In practice, a mixture of these approaches is employed in almost all cases. What matters in the end is the assessment of the overall concept, not of some outstanding feature. Inherent characteristics are easier to achieve in small reactors. However, also in this case, inherent safety does not mean absolute safety. If inherent safety characteristics were all encompassing, they would have to include self-healing effects. However, inanimate matter is incapable of such self-organization. Consequently, inherent characteristics in nuclear technology by definition should include the increased use of dissipative processes in the thermal part of the plant. (author)

The Liquid Droplet Radiator - an Ultralightweight Heat Rejection System for Efficient Energy Conversion in Space

Science.gov (United States)

Mattick, A. T.; Hertzberg, A.

1984-01-01

A heat rejection system for space is described which uses a recirculating free stream of liquid droplets in place of a solid surface to radiate waste heat. By using sufficiently small droplets ( 100 micron diameter) of low vapor pressure liquids the radiating droplet sheet can be made many times lighter than the lightest solid surface radiators (heat pipes). The liquid droplet radiator (LDR) is less vulnerable to damage by micrometeoroids than solid surface radiators, and may be transported into space far more efficiently. Analyses are presented of LDR applications in thermal and photovoltaic energy conversion which indicate that fluid handling components (droplet generator, droplet collector, heat exchanger, and pump) may comprise most of the radiator system mass. Even the unoptimized models employed yield LDR system masses less than heat pipe radiator system masses, and significant improvement is expected using design approaches that incorporate fluid handling components more efficiently. Technical problems (e.g., spacecraft contamination and electrostatic deflection of droplets) unique to this method of heat rejectioon are discussed and solutions are suggested.

Intermediate photovoltaic system application experiment operational performance report. Volume 6 for Beverly High School, Beverly, MA

Energy Technology Data Exchange (ETDEWEB)

1982-03-01

Performance data are given for the month of February, 1982 for a photovoltaic power supply at a Massachusetts high school. Data given include: monthly and daily electrical energy yield; monthly and daily insolation; monthly and daily array efficiency; energy production as a function of power level, voltage, cell temperature, and hour of day; insolation as a function of hour of the day; input, output and efficiency for each of two power conditioning units and for the total power conditioning system; energy supplied to the load by the photovoltaic system and by the grid; photovoltaic system efficiency; dollar value of the energy supplied by the photovoltaic system; capacity factor; daily photovoltaic energy to load; daily system availability and hours of daylight; heating and cooling degree days; hourly cell temperature, ambient temperature, wind speed, and insolation; average monthly wind speed; wind direction distribution; and daily data acquisition mode and recording interval plot. Also included are four site event report summaries, one involving hardware/maintenance for a power conditioning inverter, and the other three involving operations. (LEW)

Small ex-core heat pipe thermionic reactor concept (SEHPTR)

International Nuclear Information System (INIS)

Jacox, M.G.; Bennett, R.G.; Lundberg, L.B.; Miller, B.G.; Drexler, R.L.

1991-01-01

The Idaho National Engineering Laboratory (INEL) has developed an innovative space nuclear power concept with unique features and significant advantages for both Defense and Civilian space missions. The Small Ex-core Heat Pipe Thermionic Reactor (SEHPTR) concept was developed in response to Air Force needs for space nuclear power in the range of 10 to 40 kilowatts. This paper describes the SEHPTR concept and discusses the key technical issues and advantages of such a system

Urban photovoltaic electricity policies

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-10-15

This report for the International Energy Agency (IEA) made by Task 10 of the Photovoltaic Power Systems (PVPS) programme takes a look at urban photovoltaic electricity policies. The mission of the Photovoltaic Power Systems Programme is to enhance the international collaboration efforts which accelerate the development and deployment of photovoltaic solar energy as a significant and sustainable renewable energy option. The objective of Task 10 is stated as being to enhance the opportunities for wide-scale, solution-oriented application of photovoltaics in the urban environment. The goal of the study presented was to evaluate a standardised basis for urban policies regarding photovoltaic integration in a set of cities in the countries participating in the IEA's Task 10, Urban Scale PV. The investigation was focused on three topics: the present state of the policies, the prospects for future policies fostering photovoltaic deployment and the prospects for future policies to cope with large-scale photovoltaic integration. The first section analyses the state of the policies; this analysis is then confirmed in section 2, which deals with present obstacles to PV deployment and solutions to overcome them. The third section investigates future prospects for PV deployment with the question of mastering large scale integration. The report concludes that cities could formulate urban solutions by developing integrated, specific provisions for PV deployment in their urban infrastructure planning.

Photovoltaics: The present presages the future

International Nuclear Information System (INIS)

Thornton, J.; Brown, L.

1992-01-01

This article is a technical assessment on photovoltaics and what effect new technology has on the ability of photovoltaics to compete in the utility market. The topics of the article include the solar resource, photovoltaic cells and systems, thick and thin film cells, the spherical cell, photovoltaic modules and systems, photovoltaic economics and utility applications, and technology transfer programs in the area of photovoltaic manufacturing

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...

Performance of Polycrystalline Photovoltaic and Thermal Collector (PVT on Serpentine-Parallel Absorbers Design

Directory of Open Access Journals (Sweden)

Mustofa Mustofa

2017-03-01

Full Text Available This paper presents the performance of an unglazed polycrystalline photovoltaic-thermal PVT on 0.045 kg/s mass flow rate. PVT combine photovoltaic modules and solar thermal collectors, forming a single device that receive solar radiation and produces heat and electricity simultaneously. The collector figures out serpentine-parallel tubes that can prolong fluid heat conductivity from morning till afternoon. During testing, cell PV, inlet and outlet fluid temperaturs were recorded by thermocouple digital LM35 Arduino Mega 2560. Panel voltage and electric current were also noted in which they were connected to computer and presented each second data recorded. But, in this performance only shows in the certain significant time data. This because the electric current was only noted by multimeter device not the digital one. Based on these testing data, average cell efficieny was about 19%, while thermal efficiency of above 50% and correspondeng cell efficiency of 11%, respectively

Photovoltaic barometer

International Nuclear Information System (INIS)

Anon.

2011-01-01

The photovoltaic sector is continuing on track, just as the extent of solar energy's electricity-generating potential is dawning on the public mind. The annual global installation figure was up more than twofold in 2010 (rising from just short of 7000 MWp in 2009). It leapt to over 16000 MWp, bringing worldwide installed photovoltaic capacity close to 38000 MWp. The photovoltaic power generated in the European Union at the end of 2010 reached 22.5 TWh which means an additional capacity of 13023 MWp during 2010. Concerning the cumulated installed capacity, Germany and Spain rank first and second in the European Union with respectively 17370 MWp and 3808 MWp

Photovoltaic barometer

International Nuclear Information System (INIS)

2006-01-01

This annual evaluation is a synthesis of works published in 2006. Comparisons are presented between the wind power performances and European Commission White Paper and Biomass action plan objectives. The european Union photovoltaic market reached the limits of the sector supply capacity for the first time. Meanwhile the prospects of growth in the photovoltaic market are still just as good as before. Silicon producers have finally responded to the expectations of the photovoltaic industry by announcing new production capacities. These extensions led to massively investing in new production capacities, in phase with ever greater demand. This increase in demand remains, however dependent upon the energy policy. (A.L.B.)

Photovoltaic device and method

Science.gov (United States)

Cleereman, Robert J; Lesniak, Michael J; Keenihan, James R; Langmaid, Joe A; Gaston, Ryan; Eurich, Gerald K; Boven, Michelle L

2015-01-27

The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

Distributed photovoltaic systems - Addressing the utility interface issues

Science.gov (United States)

Firstman, S. I.; Vachtsevanos, G. J.

This paper reviews work conducted in the United States on the impact of dispersed photovoltaic sources upon utility operations. The photovoltaic (PV) arrays are roof-mounted on residential houses and connected, via appropriate power conditioning equipment, to the utility grid. The presence of such small (4-6 Kw) dispersed generators on the distribution network raises questions of a technical, economic and institutional nature. After a brief identification of utility interface issues, the paper addresses such technical concerns as protection of equipment and personnel safety, power quality and utility operational stability. A combination of experimental and analytical approaches has been adopted to arrive at solutions to these problems. Problem areas, under various PV system penetration scenarios, are identified and conceptual designs of protection and control equipment and operating policies are developed so that system reliability is maintained while minimizing capital costs. It is hoped that the resolution of balance-of-system and grid interface questions will ascertain the economic viability of photovoltaic systems and assist in their widespread utilization in the future.

Photovoltaic systems in agriculture

International Nuclear Information System (INIS)

Corba, Z.; Katic, V.; Milicevic, D.

2009-01-01

This paper presents the possibility of using one of the renewable energy resources in agriculture. Specifically, the paper shows the possibility of converting solar energy into electricity through photovoltaic panels. The paper includes the analysis of the energy potential of solar radiation in the AP Vojvodina (Serbia). The results of the analysis can be used for the design of photovoltaic energy systems. The amount of solar energy on the territory of the province is compared with the same data from some European countries, in order to obtain a clear picture of the possibilities of utilization of this type of renewable sources. Three examples of possible application of photovoltaic systems are presented. The first relates to the consumer who is away from the electric distribution network - photovoltaic system in island mode. The remaining two examples relate to the application of photovoltaic power sources in manufacturing plants, flowers or vegetables. Applying photovoltaic source of electrical energy to power pumps for irrigation is highlighted

Photovoltaic Product Directory and Buyers Guide

Energy Technology Data Exchange (ETDEWEB)

Watts, R.L.; Smith, S.A.; Dirks, J.A.; Mazzucchi, R.P.; Lee, V.E.

1984-04-01

The directory guide explains photovoltaic systems briefly and shows what products are available off-the-shelf. Information is given to assist in designing a photovoltaic system and on financial incentives. Help is given for determining if photovoltaic products can meet a particular buyer's needs, and information is provided on actual photovoltaic user's experiences. Detailed information is appended on various financial incentives available from state and federal governments, sources of additional information on photovoltaics, sources of various photovoltaic products, and a listing of addresses of photovoltaic products suppliers. (LEW)

Photovoltaics fundamentals, technology and practice

CERN Document Server

Mertens, Konrad

2013-01-01

Concise introduction to the basic principles of solar energy, photovoltaic systems, photovoltaic cells, photovoltaic measurement techniques, and grid connected systems, overviewing the potential of photovoltaic electricity for students and engineers new to the topic After a brief introduction to the topic of photovoltaics' history and the most important facts, Chapter 1 presents the subject of radiation, covering properties of solar radiation, radiation offer, and world energy consumption. Chapter 2 looks at the fundamentals of semiconductor physics. It discusses the build-up of semiconducto

Photovoltaic solar cell

Science.gov (United States)

Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

2013-11-26

A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

Performance Optimization of Unglazed Nanofluid Photovoltaic/Thermal System: Energy and Exergy Analyses

Directory of Open Access Journals (Sweden)

M. Imtiaz Hussain

2018-01-01

Full Text Available The focus of this paper is to predict the transient response of a nanoengineered photovoltaic thermal (PV/T system in view of energy and exergy analyses. Instead of a circular-shaped receiver, a trapezoidal-shaped receiver is employed to increase heat transfer surface area with photovoltaic (PV cells for improvement of heat extraction and thus achievement of a higher PV/T system efficiency. The dynamic mathematical model is developed using MATLAB® software by considering real-time heat transfer coefficients. The proposed model is validated with experimental data from a previous study. Negligible discrepancies were found between measured and predicted data. The validated model was further investigated in detail using different nanofluids by dispersing copper oxide (CuO and aluminum oxide (Al2O3 in pure water. The overall performance of the nanoengineered PV/T system was compared to that of a PV/T system using water only, and optimal operating conditions were determined for maximum useful energy and exergy rates. The results indicated that the CuO/water nanofluid has a notable impact on the energy and exergy efficiencies of the PV/T system compared to that of Al2O3/water nanofluid and water only cases.

Modeling Photovoltaic Power

OpenAIRE

Mavromatakis, F.; Franghiadakis, Y.; Vignola, F.

2016-01-01

A robust and reliable model describing the power produced by a photovoltaic system is needed in order to be able to detect module failures, inverter malfunction, shadowing effects and other factors that may result to energy losses. In addition, a reliable model enables an investor to perform accurate estimates of the system energy production, payback times etc. The model utilizes the global irradiance reaching the plane of the photovoltaic modules since in almost all Photovoltaic (PV) facilit...

Annual analysis of heat pipe PV/T systems for domestic hot water and electricity production

International Nuclear Information System (INIS)

Pei Gang; Fu Huide; Ji Jie; Chow Tintai; Zhang Tao

2012-01-01

Highlights: ► A novel heat pipe photovoltaic/thermal system with freeze protection was proposed. ► A detailed annual simulation model for the HP-PV/T system was presented. ► Annual performance of HP-PV/T was predicted and analyzed under different condition. - Abstract: Heat-pipe photovoltaic/thermal (HP-PV/T) systems can simultaneously provide electrical and thermal energy. Compared with traditional water-type photovoltaic/thermal systems, HP-PV/T systems can be used in cold regions without being frozen with the aid of a carefully selected heat-pipe working fluid. The current research presents a detailed simulation model of the HP-PV/T system. Using this model, the annual electrical and thermal behavior of the HP-PV/T system used in three typical climate areas of China, namely, Hong Kong, Lhasa, and Beijing, are predicted and analyzed. Two HP-PV/T systems, with and without auxiliary heating equipment, are studied annually under four different kinds of hot-water load per unit collecting area (64.5, 77.4, 90.3, and 103.2 kg/m 2 ).

Stand-alone flat-plate photovoltaic power systems: System sizing and life-cycle costing methodology for Federal agencies

Science.gov (United States)

Borden, C. S.; Volkmer, K.; Cochrane, E. H.; Lawson, A. C.

1984-01-01

A simple methodology to estimate photovoltaic system size and life-cycle costs in stand-alone applications is presented. It is designed to assist engineers at Government agencies in determining the feasibility of using small stand-alone photovoltaic systems to supply ac or dc power to the load. Photovoltaic system design considerations are presented as well as the equations for sizing the flat-plate array and the battery storage to meet the required load. Cost effectiveness of a candidate photovoltaic system is based on comparison with the life-cycle cost of alternative systems. Examples of alternative systems addressed are batteries, diesel generators, the utility grid, and other renewable energy systems.

PVSIM{copyright}: A simulation program for photovoltaic cells, modules, and arrays

Energy Technology Data Exchange (ETDEWEB)

King, D.L.; Dudley, J.K.; Boyson, W.E.

1996-06-01

An electrical simulation model for photovoltaic cells, modules, and arrays has been developed that will be useful to a wide range of analysts in the photovoltaic industry. The Microsoft{reg_sign} Windows{trademark} based program can be used to analyze individual cells, to analyze the effects of cell mismatch or reverse bias(`hot spot`) heating in modules and to analyze the performance of large arrays of modules including bypass and blocking diodes. User defined statistical variance can be applied to the fundamental parameters used to simulate the cells and diodes. The model is most appropriate for cells that can be accurately modeled using a two-diode equivalent circuit. This paper describes the simulation program and illustrates its versatility with examples.

Photovoltaic technology diffusion. Contact and interact

International Nuclear Information System (INIS)

Kruijsen, J.

1999-09-01

How can the diffusion of photovoltaic technologies be advanced? Photovoltaics convert light into electrical energy. They are environmentally friendly, reliable and have minimal maintenance requirements. Up to now, their introduction into the electricity market has been dominated by a technology push perspective. However, this has not yet resulted in a large-scale implementation. This thesis describes a network approach to advance photovoltaic diffusion and presents four guiding principles intended for the parties concerned: those who supply the photovoltaic technologies (e.g., developers of photovoltaic cells); those who integrate photovoltaic technologies into (new) product systems (e.g., engineering firms); the users of photovoltaic systems (e.g., housing corporations); and those who stimulate the use of photovoltaics (e.g., policymakers, subsidisers, branch organisations, financial institutes, and NGOs). refs

Optimum technoeconomic energy autonomous photovoltaic solution for remote consumers throughout Greece

International Nuclear Information System (INIS)

Kaldellis, J.K.

2004-01-01

Autonomous photovoltaic systems have turned into one of the most promising ways to handle the electrification requirements of numerous isolated consumers worldwide. Such an autonomous system comprises a number of photovoltaic panels, properly connected, and a battery storage device, along with the corresponding electronic equipment. Considering the high solar potential of most Greek territories, an integrated study is conducted based on long term solar potential experimental measurements in order to determine the optimum configuration of a stand alone photovoltaic system at representative locations all over Greece. The proposed solution 'guarantees' zero load rejections for all the areas and time periods examined. For this purpose, a fast and reliable numerical code 'PHOTOV-III' has been used. The algorithm provides analytical results concerning the energy autonomy and the operational status of the autonomous system components. Besides, the optimum panel tilt angle, minimizing the first installation cost of a small photovoltaic system, is predicted. Finally, by introducing available financial aspects, it is possible to determine the optimum system dimensions on a minimum first installation cost basis. According to the results obtained, an autonomous photovoltaic system can definitely contribute to solution of the urgent electrification problem of remote consumers spread throughout Greece, also improving their life quality level

Solar energy: photovoltaics

International Nuclear Information System (INIS)

Goetzberger, A.; Voss, B.; Knobloch, J.

1994-01-01

This textbooks covers the following topics: foundations of photovoltaics, solar energy, P-N junctions, physics of solar cells, high-efficiency solar cells, technology of Si solar cells, other solar cells, photovoltaic applications. (orig.)

Road map for photovoltaic electricity

International Nuclear Information System (INIS)

2011-02-01

This road map aims at highlighting industrial, technological and social challenges, at elaborating comprehensive visions, at highlighting technological locks, and at outlining research needs for the photovoltaic sector. It considers the following sector components: preparation of photo-sensitive materials, manufacturing of photovoltaic cells, manufacturing of photovoltaic arrays, design and manufacturing of electric equipment to control photovoltaic arrays and to connect them to the grid. It highlights the demand for photovoltaic installations, analyzes the value chain, proposes a vision of the sector by 2050 and defines target for 2020, discusses needs for demonstration and experimentation

Concentrator Photovoltaics

CERN Document Server

Luque, Antonio L

2007-01-01

Photovoltaic solar-energy conversion is one of the most promising technologies for generating renewable energy, and conversion of concentrated sunlight can lead to reduced cost for solar electricity. In fact, photovoltaic conversion of concentrated sunlight insures an efficient and cost-effective sustainable power resource. This book gives an overview of all components, e.g. cells, concentrators, modules and systems, for systems of concentrator photovoltaics. The authors report on significant results related to design, technology, and applications, and also cover the fundamental physics and market considerations. Specific contributions include: theory and practice of sunlight concentrators; an overview of concentrator PV activities; a description of concentrator solar cells; design and technology of modules and systems; manufacturing aspects; and a market study.

A novel application for concentrator photovoltaic in the field of agriculture photovoltaics

Science.gov (United States)

Liu, Luqing; Guan, Chenggang; Zhang, Fangxin; Li, Ming; Lv, Hui; Liu, Yang; Yao, Peijun; Ingenhoff, Jan; Liu, Wen

2017-09-01

Agriculture photovoltaics is a trend setting area which has already led to a new industrial revolution. Shortage of land in some countries and desertification of land where regular solar panels are deployed are some of the major problems in the photovoltaic industry. Concentrator photovoltaics experienced a decline in applicability after the cost erosion of regular solar panels at the end of the last decade. We demonstrate a novel and unique application for concentrator photovoltaics tackling at a same time the issue of conventional photovoltaics preventing the land being used for agricultural purpose where ever solar panels are installed. We leverage the principle of diffractive and interference technology to split the sun light into transmitted wavelengths necessary for plant growth and reflected wavelengths useful for solar energy generation. The technology has been successfully implemented in field trials and sophisticated scientific studies have been undertaken to evaluate the suitability of this technology for competitive solar power generation and simultaneous high-quality plant growth. The average efficiency of the agriculture photovoltaic system has reached more than 8% and the average efficiency of the CPV system is 6.80%.

Photovoltaic Solar Energy

International Nuclear Information System (INIS)

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

1998-01-01

A short historical review of the technological advances; the current state and the perspectives of the materials for photovoltaic applications is made. Thereinafter, the general aspects of the physical principles and fundamental parameters that govern the operation of the solar cells are described. To way of the example, a methodology for the design and facilities size of a photovoltaic system is applied. Finally, the perspectives of photovoltaic solar energy in relationship to the market and political of development are mentioned

Technical-and-Economic Efficiency of Draft Enriched with Oxygen in Small-Capacity Heating Boilers

Directory of Open Access Journals (Sweden)

P. Ratnikov

2013-01-01

Full Text Available Data on complex experimental and theoretical investigations pertaining to efficiency of oxygen-enriched draft in the small-capacity heating boilers as exemplified by the plant HEIZA (HW-S-10/K have been presented in the paper. The paper provides a calculation model of heating processes in heat generator burner (as exemplified by HEIZA plant. Simulation of heating processes in the operational zone has been executed in paper. The experimental data have proved model adequacy. The calculation scheme of the plant will be used in future for determination of power and ecological efficiency of draft enrichment with oxygen.

Photovoltaic roof construction

Energy Technology Data Exchange (ETDEWEB)

Hawley, W.W.

1980-02-26

In a batten-seam roof construction employing at least one photovoltaic cell module, the electrical conduits employed with the at least one photovoltaic cell module are disposed primarily under the battens of the roof.

Organic Semiconductor Photovoltaics

Science.gov (United States)

Sariciftci, Niyazi Serdar

2005-03-01

Recent developments on organic photovoltaic elements are reviewed. Semiconducting conjugated polymers and molecules as well as nanocrystalline inorganic semiconductors are used in composite thin films. The photophysics of such photoactive devices is based on the photoinduced charge transfer from donor type semiconducting molecules onto acceptor type molecules such as Buckminsterfullerene, C60 and/or nanoparticles. Similar to the first steps in natural photosynthesis, this photoinduced electron transfer leads to a number of potentially interesting applications which include sensitization of the photoconductivity and photovoltaic phenomena. Examples of photovoltaic architectures are discussed with their potential in terrestrial solar energy conversion. Several materials are introduced and discussed for their photovoltaic activities. Furthermore, nanomorphology has been investigated with AFM, SEM and TEM. The morphology/property relationship for a given photoactive system is found to be a major effect.

Solar Radiation on Mars: Tracking Photovoltaic Array

Science.gov (United States)

Appelbaum, Joseph; Flood, Dennis J.; Crutchik, Marcos

1994-01-01

A photovoltaic power source for surface-based operation on Mars can offer many advantages. Detailed information on solar radiation characteristics on Mars and the insolation on various types of collector surfaces are necessary for effective design of future planned photovoltaic systems. In this article we have presented analytical expressions for solar radiation calculation and solar radiation data for single axis (of various types) and two axis tracking surfaces and compared the insulation to horizontal and inclined surfaces. For clear skies (low atmospheric dust load) tracking surfaces resulted in higher insolation than stationary surfaces, whereas for highly dusty atmospheres, the difference is small. The insolation on the different types of stationary and tracking surfaces depend on latitude, season and optical depth of the atmosphere, and the duration of system operation. These insolations have to be compared for each mission.

Performance Study of Photovoltaic-Thermal (Pv/T) Solar Collector with ·-Grooved Absorber Plate

International Nuclear Information System (INIS)

Mohd Yusof Othman; Hafidz Ruslan; Kamaruzzaman Sopian; Jin, G.L.

2009-01-01

A hybrid photovoltaic-thermal solar collector has been designed, built and its performance has been studied. The advantage of the collector is that it can generate electricity and heat simultaneously. Photovoltaic module SHARP NE-80E2EA with maximum output power of 80 W was used to generate electricity. The module also acts as heat absorber of the collector. Single pass ·-groove collector made of aluminium sheet with 0.7 mm thickness has been used to collect heat generated. Study was conducted under a designed halogen lamps solar simulator with intensities set at 386 ± 8 Wm -2 and 817 ± 8 Wm -2 . The speed of air passing through the collector was set between (69.6 ± 2.2) x 10 -4 kg/s to (695.8 ± 2.2) x 10 -4 kg/s. The objective of the study is to compare the performance of PV/T collector with and without ·-groove absorber. The study found that the PV/T collector with ·-groove absorber plate has higher efficiency than the PV/T without ·-groove absorber. The electrical and thermal efficiencies are also increased when radiation intensity and speed of air increase. (author)

Integration between electric heat pump and PV system to increase self-consumption of an office application

Directory of Open Access Journals (Sweden)

Roselli Carlo

2017-01-01

Full Text Available The paper examines a solar electric driven heat pump serving an office building located in southern Italy. To satisfy space heating and cooling demand a heat pump activated by electric energy available from solar photovoltaic plant is here considered. In order to improve the self-consumption of electricity available from photovoltaic system different configurations were considered introducing an electric storage and an electric vehicle. Dynamic simulations to evaluate energy performance of the system varying photovoltaic peak power (4.5–7.5 kW have been carried out. The proposed system achieves a fossil fuel primary energy saving up to about 96% in comparison to the reference conventional system based on a natural gas fired boiler, an electric chiller and the national electric grid. The results show that fossil fuel primary energy saving is higher when there are no storage battery and electric vehicle.

Dynamic behavior of small heat shock protein inhibition on amyloid fibrillization of a small peptide (SSTSAA) from RNase A

International Nuclear Information System (INIS)

Xi, Dong; Dong, Xiao; Deng, Wei; Lai, Luhua

2011-01-01

Highlights: ► Mechanism of small heat shock protein inhibition on fibril formation was studied. ► Peptide SSTSAA with modified ends was used for amyloid fibril formation. ► FRET signal was followed during the fibril formation. ► Mj HSP16.5 inhibits fibril formation when introduced in the lag phase. ► Mj HSP16.5 slows down fibril formation when introduced after the lag phase. -- Abstract: Small heat shock proteins, a class of molecular chaperones, are reported to inhibit amyloid fibril formation in vitro, while the mechanism of inhibition remains unknown. In the present study, we investigated the mechanism by which Mj HSP16.5 inhibits amyloid fibril formation of a small peptide (SSTSAA) from RNase A. A model peptide (dansyl-SSTSAA-W) was designed by introducing a pair of fluorescence resonance energy transfer (FRET) probes into the peptide, allowing for the monitoring of fibril formation by this experimental model. Mj HSP16.5 completely inhibited fibril formation of the model peptide at a molar ratio of 1:120. The dynamic process of fibril formation, revealed by FRET, circular dichroism, and electron microscopy, showed a lag phase of about 2 h followed by a fast growth period. The effect of Mj HSP16.5 on amyloid fibril formation was investigated by adding it into the incubation solution during different growth phases. Adding Mj HSP16.5 to the incubating peptide before or during the lag phase completely inhibited fibril formation. However, introducing Mj HSP16.5 after the lag phase only slowed down the fibril formation process by adhering to the already formed fibrils. These findings provide insight into the inhibitory roles of small heat shock proteins on amyloid fibril formation at the molecular level.

Dynamic behavior of small heat shock protein inhibition on amyloid fibrillization of a small peptide (SSTSAA) from RNase A

Energy Technology Data Exchange (ETDEWEB)

Xi, Dong [BNLMS, State Key Laboratory of Structural Chemistry for Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Center for Theoretical Biology, Peking University, Beijing 100871 (China); Dong, Xiao; Deng, Wei [BNLMS, State Key Laboratory of Structural Chemistry for Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Lai, Luhua, E-mail: lhlai@pku.edu.cn [BNLMS, State Key Laboratory of Structural Chemistry for Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Center for Theoretical Biology, Peking University, Beijing 100871 (China)

2011-12-09

Highlights: Black-Right-Pointing-Pointer Mechanism of small heat shock protein inhibition on fibril formation was studied. Black-Right-Pointing-Pointer Peptide SSTSAA with modified ends was used for amyloid fibril formation. Black-Right-Pointing-Pointer FRET signal was followed during the fibril formation. Black-Right-Pointing-Pointer Mj HSP16.5 inhibits fibril formation when introduced in the lag phase. Black-Right-Pointing-Pointer Mj HSP16.5 slows down fibril formation when introduced after the lag phase. -- Abstract: Small heat shock proteins, a class of molecular chaperones, are reported to inhibit amyloid fibril formation in vitro, while the mechanism of inhibition remains unknown. In the present study, we investigated the mechanism by which Mj HSP16.5 inhibits amyloid fibril formation of a small peptide (SSTSAA) from RNase A. A model peptide (dansyl-SSTSAA-W) was designed by introducing a pair of fluorescence resonance energy transfer (FRET) probes into the peptide, allowing for the monitoring of fibril formation by this experimental model. Mj HSP16.5 completely inhibited fibril formation of the model peptide at a molar ratio of 1:120. The dynamic process of fibril formation, revealed by FRET, circular dichroism, and electron microscopy, showed a lag phase of about 2 h followed by a fast growth period. The effect of Mj HSP16.5 on amyloid fibril formation was investigated by adding it into the incubation solution during different growth phases. Adding Mj HSP16.5 to the incubating peptide before or during the lag phase completely inhibited fibril formation. However, introducing Mj HSP16.5 after the lag phase only slowed down the fibril formation process by adhering to the already formed fibrils. These findings provide insight into the inhibitory roles of small heat shock proteins on amyloid fibril formation at the molecular level.

Increased power to heat ratio of small scale CHP plants using biomass fuels and natural gas

International Nuclear Information System (INIS)

Savola, Tuula; Fogelholm, Carl-Johan

2006-01-01

In this paper, we present a systematic study of process changes for increased power production in 1-20 MW e combined heat and power (CHP) plants. The changes are simulated, and their economic feasibility evaluated by using existing small scale CHP case plants. Increasing power production in decentralised CHP plants that operate according to a certain heat demand could reduce the fuel consumption and CO 2 emissions per power unit produced and improve the feasibility of CHP plant investments. The CHP plant process changes were simulated under design and off design conditions and an analysis of power and heat production, investment costs and CO 2 emissions was performed over the whole annual heat demand. The results show that using biomass fuels, there are profitable possibilities to increase the current power to heat ratios, 0.23-0.48, of the small scale CHP plants up to 0.26-0.56, depending on the size of the plant. The profitable changes were a two stage district heat exchanger and the addition of a steam reheater and a feed water preheater. If natural gas is used as an additional fuel, the power to heat ratio may be increased up to 0.35-0.65 by integrating a gas engine into the process. If the CO 2 savings from the changes are also taken into account, the economic feasibility of the changes increases. The results of this work offer useful performance simulation and investment cost knowledge for the development of more efficient and economically feasible small scale CHP processes

Small-angle X-ray scattering studies of metastable intermediates of beta-lactoglobulin isolated after heat-induced aggregation

DEFF Research Database (Denmark)

Carrotta, R.; Arleth, L.; Pedersen, J.S.

2003-01-01

Small-angle x-ray scattering was used for studying intermediate species, isolated after heat-induced aggregation of the A variant of bovine P-lactoglobulin. The intermediates were separated in two fractions, the heated metastable dimer and heated metastable oligomers larger than the dimer. The pa...

Building opportunities for photovoltaics in the U.S. Final report [PV BONUS

Energy Technology Data Exchange (ETDEWEB)

Michael Nicklas

1999-09-08

The objective of the North Carolina's PV Bonus Team was to develop and demonstrate a commercially viable, building-integrated, photovoltaic system that, in addition to providing electricity, would capture and effectively utilize the thermal energy produced by the photovoltaic array. This project objective was successfully achieved by designing, testing, constructing, and monitoring two roof integrated photovoltaic systems--one on a Applebee's Restaurant in Salisbury, North Carolina and the second on a Central Carolina Bank in Bessemer City, North Carolina. The goal of Innovative Design is to now use these successful demonstrations to facilitate entry of building integrated, pv/thermal systems into the marketplace. The strategy was to develop the two systems that could be utilized in future applications. Both systems were designed and then constructed at the North Carolina Solar Center at North Carolina State University. After extensive testing at the North Carolina Solar Center, the systems were moved to the actual construction sites and implemented. The Applebee's Restaurant system was designed to substitute for the roof assembly of a low sloping, south-facing sunspace roof that typically incorporated clay tile. After monitoring the installed system for one year it was determined that the 1.2 kilowatt (peak) system produces an average peak reduction of 1 kilowatt (rated peak is 1.7 kiloWatts), saves 1,529 kilowatt-hours of electricity, and offsets 11,776 kilowatt-hours of thermal energy savings used to pre-heat water. A DC fan connected directly to eight of the thirty-two amorphous modules moves air through air passages mounted on the backside of the modules and into a closed loop duct system to a heat exchanger. This heat exchanger is, in turn, connected to a pre-heat hot water tank that is used to heat the water for the restaurant. The Central Carolina Bank system was designed to substitute for the roof assembly of the drive-in window area of the

Photovoltaic product directory and buyers guide

Energy Technology Data Exchange (ETDEWEB)

Watts, R.L.; Smith, S.A.; Mazzucchi, R.P.

1981-06-01

Basic information on photovoltaic conversion technology is provided for those unfamiliar with the field. Various types of photovoltaic products and systems currently available off-the-shelf are described. These include products without batteries, battery chargers, power packages, home electric systems, and partial systems. Procedures are given for designing a photovoltaic system from scratch. A few custom photovoltaic systems are described, and a list is compiled of photovoltaic firms which can provide custom systems. Guidance is offered for deciding whether or not to use photovoltaic products. A variety of installations are described and their performance is appraised by the owners. Information is given on various financial incentives available from state and federal governments. Sources of additional information on photovoltaics are listed. A matrix is provided indicating the sources of various types of photovoltaic products. The addresses of suppliers are listed. (LEW)

Design and construction of radiant panel for cooling and heating with photovoltaic and thermoelectric element modules; Taiyo denchi to netsuden soshi module wo mochiita fukusha reidanbo panel no sekkei oyobi shisaku

Energy Technology Data Exchange (ETDEWEB)

Sato, M; Tani, T [Science University of Tokyo, Tokyo (Japan); Kadotani, K; Imaizumi, H [Komatsu Ltd., Tokyo (Japan)

1997-11-25

Utilizing cooling properties and current voltage characteristics of a small cooling panel using thermoelectric elements which had been fabricated previously on a trial basis, design and prototype production were executed on a large radiant cooling and heating panel driven by photovoltaic cell modules. The panel design set the cooling area to about 0.5 m {sup 2} and the number of elements to 70 pieces, and optimum number of elements in series and parallel connection was derived. As a result of the analysis, it was made clear that the optimum number of thermoelectric module arrays in series and parallel connection varies depending on insolation intensity. It was found preferable that the number of parallel connection array be set to one to two in a region or time period in which low insolation intensity is distributed in greater amount. In the case where high insolation intensity is distributed in a greater amount, setting it to two to three is preferable. By using the structured design method and the HASP Tokyo data, thermoelectric element modules were interconnected with 35 modules in series and two in parallel on a cooling panel installed on the roof of the Science University of Tokyo. A simulation result revealed that the average temperature difference on the cooled surface in summer is 4.37 degC, and the solar cell utilization rate is 0.67. It is necessary in the future to improve heat dissipation efficiency and area ratio. 1 ref., 12 figs., 5 tabs.

Switchable photovoltaic windows enabled by reversible photothermal complex dissociation from methylammonium lead iodide.

Science.gov (United States)

Wheeler, Lance M; Moore, David T; Ihly, Rachelle; Stanton, Noah J; Miller, Elisa M; Tenent, Robert C; Blackburn, Jeffrey L; Neale, Nathan R

2017-11-23

Materials with switchable absorption properties have been widely used for smart window applications to reduce energy consumption and enhance occupant comfort in buildings. In this work, we combine the benefits of smart windows with energy conversion by producing a photovoltaic device with a switchable absorber layer that dynamically responds to sunlight. Upon illumination, photothermal heating switches the absorber layer-composed of a metal halide perovskite-methylamine complex-from a transparent state (68% visible transmittance) to an absorbing, photovoltaic colored state (less than 3% visible transmittance) due to dissociation of methylamine. After cooling, the methylamine complex is re-formed, returning the absorber layer to the transparent state in which the device acts as a window to visible light. The thermodynamics of switching and performance of the device are described. This work validates a photovoltaic window technology that circumvents the fundamental tradeoff between efficient solar conversion and high visible light transmittance that limits conventional semitransparent PV window designs.

Snapshot of photovoltaics - February 2018

Science.gov (United States)

Jäger-Waldau, Arnulf

2018-05-01

Solar photovoltaic electricity generation is the fastest growing power generation source world-wide. The significant cost reduction of solar PV over the last decade, and the zero fuel cost volatility have increased the attractiveness. In 2017, the newly installed solar PV power of over 90 GW was more than all the world-wide cumulative installed PV capacity until the mid of 2012. China was again the main driver behind this strong growth with more than 50 GW of annual installations in 2017. Apart from the electricity sector, renewable energy sources for the generation of heat and environmental friendly synthetic-fuels for the transport sector will become more and more important in the future.

An electron-deficient small molecule accessible from sustainable synthesis and building blocks for use as a fullerene alternative in organic photovoltaics.

Science.gov (United States)

McAfee, Seth M; Topple, Jessica M; Payne, Abby-Jo; Sun, Jon-Paul; Hill, Ian G; Welch, Gregory C

2015-04-27

An electron-deficient small molecule accessible from sustainable isoindigo and phthalimide building blocks was synthesized via optimized synthetic procedures that incorporate microwave-assisted synthesis and a heterogeneous catalyst for Suzuki coupling, and direct heteroarylation carbon-carbon bond forming reactions. The material was designed as a non-fullerene acceptor with the help of DFT calculations and characterized by optical, electronic, and thermal analysis. Further investigation of the material revealed a differing solid-state morphology with the use of three well-known processing conditions: thermal annealing, solvent vapor annealing and small volume fractions of 1,8-diiodooctane (DIO) additive. These unique morphologies persist in the active layer blends and have demonstrated a distinct influence on device performance. Organic photovoltaic-bulk heterojunction (OPV-BHJ) devices show an inherently high open circuit voltage (Voc ) with the best power conversion efficiency (PCE) cells reaching 1.0 V with 0.4 v/v % DIO as a processing additive. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photovoltaic cell module and method of forming

Science.gov (United States)

Howell, Malinda; Juen, Donnie; Ketola, Barry; Tomalia, Mary Kay

2017-12-12

A photovoltaic cell module, a photovoltaic array including at least two modules, and a method of forming the module are provided. The module includes a first outermost layer and a photovoltaic cell disposed on the first outermost layer. The module also includes a second outermost layer disposed on the photovoltaic cell and sandwiching the photovoltaic cell between the second outermost layer and the first outermost layer. The method of forming the module includes the steps of disposing the photovoltaic cell on the first outermost layer, disposing a silicone composition on the photovoltaic cell, and compressing the first outermost layer, the photovoltaic cell, and the second layer to form the photovoltaic cell module.

Photovoltaic power generation system free of bypass diodes

Science.gov (United States)

Lentine, Anthony L.; Okandan, Murat; Nielson, Gregory N.

2015-07-28

A photovoltaic power generation system that includes a solar panel that is free of bypass diodes is described herein. The solar panel includes a plurality of photovoltaic sub-modules, wherein at least two of photovoltaic sub-modules in the plurality of photovoltaic sub-modules are electrically connected in parallel. A photovoltaic sub-module includes a plurality of groups of electrically connected photovoltaic cells, wherein at least two of the groups are electrically connected in series. A photovoltaic group includes a plurality of strings of photovoltaic cells, wherein a string of photovoltaic cells comprises a plurality of photovoltaic cells electrically connected in series. The strings of photovoltaic cells are electrically connected in parallel, and the photovoltaic cells are microsystem-enabled photovoltaic cells.

Photovoltaics in the Department of Defense

International Nuclear Information System (INIS)

Chapman, R.N.

1997-01-01

This paper documents the history of photovoltaic use within the Department of Defense leading up to the installation of 2.1 MW of photovoltaics underway today. This history describes the evolution of the Department of Defense's Tri-Service Photovoltaic Review Committee and the committee's strategic plan to realize photovoltaic's full potential through outreach, conditioning of the federal procurement system, and specific project development. The Photovoltaic Review Committee estimates photovoltaic's potential at nearly 4,000 MW, of which about 700 MW are considered to be cost-effective at today's prices. The paper describes photovoltaic's potential within the Department of Defense, the status and features of the 2.1-MW worth of photovoltaic systems under installation, and how these systems are selected and implemented. The paper also documents support provided to the Department of Defense by the Department of Energy dating back to the late 70s. copyright 1997 American Institute of Physics

Solar photovoltaic (PV) energy; latest developments in the building integrated and hybrid PV systems

International Nuclear Information System (INIS)

Zahedi, A.

2006-01-01

Environmental concerns are growing and interest in environmental issues is increasing and the idea of generating electricity with less pollution is becoming more and more attractive. Unlike conventional generation systems, fuel of the solar photovoltaic energy is available at no cost. And solar photovoltaic energy systems generate electricity pollution-free and can easily be installed on the roof of residential as well as on the wall of commercial buildings as grid-connected PV application. In addition to grid-connected rooftop PV systems, solar photovoltaic energy offers a solution for supplying electricity to remote located communities and facilities, those not accessible by electricity companies. The interest in solar photovoltaic energy is growing worldwide. Today, more than 3500MW of photovoltaic systems have been installed all over the world. Since 1970, the PV price has continuously dropped [8]. This price drop has encouraged worldwide application of small-scale residential PV systems. These recent developments have led researchers concerned with the environment to undertake extensive research projects for harnessing renewable energy sources including solar energy. The usage of solar photovoltaic as a source of energy is considered more seriously making future of this technology looks promising. The objective of this contribution is to present the latest developments in the area of solar photovoltaic energy systems. A further objective of this contribution is to discuss the long-term prospect of the solar photovoltaic energy as a sustainable energy supply. [Author

US photovoltaic patents: 1991--1993

Energy Technology Data Exchange (ETDEWEB)

Pohle, L

1995-03-01

This document contains US patents on terrestrial photovoltaic (PV) power applications, including systems, components, and materials as well as manufacturing and support functions. The patent entries in this document were issued from 1991 to 1993. The entries were located by searching USPA, the database of the US Patent Office. The final search retrieved all patents under the class ``Batteries, Thermoelectric and Photoelectric`` and the subclasses ``Photoelectric,`` ``Testing,`` and ``Applications.`` The search also located patents that contained the words ``photovoltaic(s)`` or ``solar cell(s)`` and their derivatives. After the initial list was compiled, most of the patents on the following subjects were excluded: space photovoltaic technology, use of the photovoltaic effect for detectors, and subjects only peripherally concerned with photovoltaic. Some patents on these three subjects were included when ft appeared that those inventions might be of use in terrestrial PV power technologies.

New Markets for Solar Photovoltaic Power Systems

Science.gov (United States)

Thomas, Chacko; Jennings, Philip; Singh, Dilawar

2007-10-01

Over the past five years solar photovoltaic (PV) power supply systems have matured and are now being deployed on a much larger scale. The traditional small-scale remote area power supply systems are still important and village electrification is also a large and growing market but large scale, grid-connected systems and building integrated systems are now being deployed in many countries. This growth has been aided by imaginative government policies in several countries and the overall result is a growth rate of over 40% per annum in the sales of PV systems. Optimistic forecasts are being made about the future of PV power as a major source of sustainable energy. Plans are now being formulated by the IEA for very large-scale PV installations of more than 100 MW peak output. The Australian Government has announced a subsidy for a large solar photovoltaic power station of 154 MW in Victoria, based on the concentrator technology developed in Australia. In Western Australia a proposal has been submitted to the State Government for a 2 MW photovoltaic power system to provide fringe of grid support at Perenjori. This paper outlines the technologies, designs, management and policies that underpin these exciting developments in solar PV power.

Flow boiling heat transfer of carbon dioxide inside a small-sized microfin tube

Energy Technology Data Exchange (ETDEWEB)

Dang, Chaobin; Haraguchi, Nobori; Hihara, Eiji [Department of Human and Engineered Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa-shi, Chiba 277-8563 (Japan)

2010-06-15

This study investigated the flow boiling heat transfer of carbon dioxide inside a small-sized microfin tube (mean inner diameter: 2.0 mm; helix angle: 6.3 ) at a saturation temperature of 15 C, and heat and mass flux ranges of 4.5-18 kW m{sup -2} and 360-720 kg m{sup -2} s{sup -1}, respectively. Although, experimental results indicated that heat flux has a significant effect on the heat transfer coefficient, the coefficient does not always increase with mass flux, as in the case of conventional refrigerants such as HFCs or HCFCs. Under certain conditions, the heat transfer coefficient at a high mass flux was lower than that at a lower mass flux, indicating that convective heat transfer had a suppression effect on nucleate boiling. The heat transfer coefficients in the microfin tubes were 1.9{proportional_to}2.3 times the values in smooth tubes of the same diameter under the same experimental conditions, and the dryout quality was much higher, ranging from 0.9 to 0.95. The experimental results indicated that using microfin tubes may considerably increase the overall heat transfer performance. (author)

Photovoltaic applications

International Nuclear Information System (INIS)

Sidrach, M.

1992-01-01

The most common terrestrial applications of photovoltaic plants are reviewed. Classification of applications can be done considering end-use sectors and load profiles (consumption demand). For those systems with direct coupling the working point is determined by the intersection of the load line with the I-V curve Design guidelines are provided for photovoltaic systems. This lecture focusses on the distribution system and safeguards

Second update of the database of photovoltaic installations in the UK

Energy Technology Data Exchange (ETDEWEB)

Taylor, D; Bruhns, H

2001-07-01

This update of the database of photovoltaic (PV) installations in the UK developed by Altechnica for the Department of Trade and Industry has double the number of records of the previous edition, and focuses on the use of photovoltaic (PV) installations for buildings, for example using some form of a PV array, building integrated PV module, and building attached PV array. The growth in building related PV installations is examined along with the use of PV in telecommunication equipment, navigation buoys and light vessels, buildings, pumps for solar water heating systems, schools, lighthouses, and petrol stations. Details are given of the electronic data entry form for the database and the increase in the number of fields to allow additional information such as tilt angle and orientation area of the array to be added.

Structure and function of small heat shock/alpha-crystallin proteins: established concepts and emerging ideas.

Science.gov (United States)

MacRae, T H

2000-06-01

Small heat shock/alpha-crystallin proteins are defined by conserved sequence of approximately 90 amino acid residues, termed the alpha-crystallin domain, which is bounded by variable amino- and carboxy-terminal extensions. These proteins form oligomers, most of uncertain quaternary structure, and oligomerization is prerequisite to their function as molecular chaperones. Sequence modelling and physical analyses show that the secondary structure of small heat shock/alpha-crystallin proteins is predominately beta-pleated sheet. Crystallography, site-directed spin-labelling and yeast two-hybrid selection demonstrate regions of secondary structure within the alpha-crystallin domain that interact during oligomer assembly, a process also dependent on the amino terminus. Oligomers are dynamic, exhibiting subunit exchange and organizational plasticity, perhaps leading to functional diversity. Exposure of hydrophobic residues by structural modification facilitates chaperoning where denaturing proteins in the molten globule state associate with oligomers. The flexible carboxy-terminal extension contributes to chaperone activity by enhancing the solubility of small heat shock/alpha-crystallin proteins. Site-directed mutagenesis has yielded proteins where the effect of the change on structure and function depends upon the residue modified, the organism under study and the analytical techniques used. Most revealing, substitution of a conserved arginine residue within the alpha-crystallin domain has a major impact on quaternary structure and chaperone action probably through realignment of beta-sheets. These mutations are linked to inherited diseases. Oligomer size is regulated by a stress-responsive cascade including MAPKAP kinase 2/3 and p38. Phosphorylation of small heat shock/alpha-crystallin proteins has important consequences within stressed cells, especially for microfilaments.

The active control strategy on the output power for photovoltaic-storage systems based on extended PQ-QV-PV Node

Science.gov (United States)

Xu, Chen; Zhou, Bao-Rong; Zhai, Jian-Wei; Zhang, Yong-Jun; Yi, Ying-Qi

2017-05-01

In order to solve the problem of voltage exceeding specified limits and improve the penetration of photovoltaic in distribution network, we can make full use of the active power regulation ability of energy storage(ES) and the reactive power regulation ability of grid-connected photovoltaic inverter to provide support of active power and reactive power for distribution network. A strategy of actively controlling the output power for photovoltaic-storage system based on extended PQ-QV-PV node by analyzing the voltage regulating mechanism of point of commom coupling(PCC) of photovoltaic with energy storage(PVES) by controlling photovoltaic inverter and energy storage. The strategy set a small wave range of voltage to every photovoltaic by making the type of PCC convert among PQ, PV and QV. The simulation results indicate that the active control method can provide a better solution to the problem of voltage exceeding specified limits when photovoltaic is connectted to electric distribution network.

Thin film photovoltaic panel and method

Science.gov (United States)

Ackerman, Bruce; Albright, Scot P.; Jordan, John F.

1991-06-11

A thin film photovoltaic panel includes a backcap for protecting the active components of the photovoltaic cells from adverse environmental elements. A spacing between the backcap and a top electrode layer is preferably filled with a desiccant to further reduce water vapor contamination of the environment surrounding the photovoltaic cells. The contamination of the spacing between the backcap and the cells may be further reduced by passing a selected gas through the spacing subsequent to sealing the backcap to the base of the photovoltaic panels, and once purged this spacing may be filled with an inert gas. The techniques of the present invention are preferably applied to thin film photovoltaic panels each formed from a plurality of photovoltaic cells arranged on a vitreous substrate. The stability of photovoltaic conversion efficiency remains relatively high during the life of the photovoltaic panel, and the cost of manufacturing highly efficient panels with such improved stability is significantly reduced.

Photovoltaic engineering handbook

Energy Technology Data Exchange (ETDEWEB)

Lasnier, F; Ang, T G [Asian Institute of Technolgoy, Bangkok (TH)

1990-01-01

The Photovoltaic Engineering Handbook is a comprehensive 'nuts and bolts' guide to photovoltaic technology and systems engineering aimed at engineers and designers in the field. It is the first book to look closely at the practical problems involved in evaluating and setting up a PV power system. The authors' comprehensive insight into the different procedures and decisions that a designer needs to make. The book is unique in its coverage and the technical information is presented in a concise and simple way to enable engineers from a wide range of backgrounds to initiate, assess, analyse and design a PV system. Energy planners making decisions on the most appropriate system for specific needs will also benefit from reading this book. Topics covered include technological processes, including solar cell technology, the photovoltaic generator, photovoltaic systems engineering; characterization and testing methods, sizing procedure; economic analysis and instrumentation. (author).

Interactive economic analysis of small-scale heating plant

Energy Technology Data Exchange (ETDEWEB)

Landen, R.A.; Sanders, D.L.; Douglas, B.H.

1998-11-01

This report contains the work that has been undertaken by LRZ Limited in pursuance of this agreement. The potential for small-scale biomass heating systems is identified, and surrounding issues relating to acceptance are discussed. Such systems are described, and the origins of capital and running costs examined. A full review of the calculation methods for boiler plant size and fuel consumption is made, and subsequently expounded in four varying case studies. The results of this work are discussed, and the final development of the computer models is reviewed, incorporating further refinements to the method. Finally, data not contained in the text is incorporated in comprehensive appendices. (author)

Cryogenic Loop Heat Pipes for the Cooling of Small Particle Detectors at CERN

OpenAIRE

Pereira, H; Haug, F; Silva, P; Wu, J; Koettig, T

2010-01-01

The loop heat pipe (LHP) is among the most effective heat transfer elements. Its principle is based on a continuous evaporation/condensation process and its passive nature does not require any mechanical devices such as pumps to circulate the cooling agent. Instead a porous wick structure in the evaporator provides the capillary pumping forces to drive the fluid [1]. Cryogenic LHP are investigated as potential candidates for the cooling of future small-scale particle detectors and upgrades of...

Progress in high-efficient solution process organic photovoltaic devices fundamentals, materials, devices and fabrication

CERN Document Server

Li, Gang

2015-01-01

This book presents an important technique to process organic photovoltaic devices. The basics, materials aspects and manufacturing of photovoltaic devices with solution processing are explained. Solution processable organic solar cells - polymer or solution processable small molecules - have the potential to significantly reduce the costs for solar electricity and energy payback time due to the low material costs for the cells, low cost and fast fabrication processes (ambient, roll-to-roll), high material utilization etc. In addition, organic photovoltaics (OPV) also provides attractive properties like flexibility, colorful displays and transparency which could open new market opportunities. The material and device innovations lead to improved efficiency by 8% for organic photovoltaic solar cells, compared to 4% in 2005. Both academic and industry research have significant interest in the development of this technology. This book gives an overview of the booming technology, focusing on the solution process fo...

Solar Photovoltaic Cells.

Science.gov (United States)

Mickey, Charles D.

1981-01-01

Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

Modeling Small Scale Solar Powered ORC Unit for Standalone Application

Directory of Open Access Journals (Sweden)

Enrico Bocci

2012-01-01

Full Text Available When the electricity from the grid is not available, the generation of electricity in remote areas is an essential challenge to satisfy important needs. In many developing countries the power generation from Diesel engines is the applied technical solution. However the cost and supply of fuel make a strong dependency of the communities on the external support. Alternatives to fuel combustion can be found in photovoltaic generators, and, with suitable conditions, small wind turbines or microhydroplants. The aim of the paper is to simulate the power generation of a generating unit using the Rankine Cycle and using refrigerant R245fa as a working fluid. The generation unit has thermal solar panels as heat source and photovoltaic modules for the needs of the auxiliary items (pumps, electronics, etc.. The paper illustrates the modeling of the system using TRNSYS platform, highlighting standard and “ad hoc” developed components as well as the global system efficiency. In the future the results of the simulation will be compared with the data collected from the 3 kW prototype under construction in the Tuscia University in Italy.

Performance of U.S. hybrid distributed energy systems: Solar photovoltaic, battery and combined heat and power

International Nuclear Information System (INIS)

Shah, Kunal K.; Mundada, Aishwarya S.; Pearce, J.M.

2015-01-01

Highlights: • Simulated PV + battery + CHP hybrid systems deployed in three U.S. regions. • Used hybrid optimization model for electric renewable pro microgrid analysis. • Limited size of each sub-module to singe family house size. • Results show that the electricity generated meets residential load demand. • Hybrid systems are technically viable in hot, moderate and cold climates in U.S. - Abstract: Until recently, the relatively high levelized cost of electricity from solar photovoltaic (PV) technology limited deployment; however, recent cost reductions, combined with various financial incentives and innovative financing techniques, have made PV fully competitive with conventional sources in many American regions. In addition, the costs of electrical storage have also declined enough to make PV + battery systems potentially economically viable for a mass-scale off-grid low-emission transition. However, many regions in the U.S. (e.g. Northern areas) cannot have off-grid PV systems without prohibitively large battery systems. Small-scale combined heat and power (CHP) systems provide a potential solution for off-grid power backup of residential-scale PV + battery arrays, while also minimizing emissions from conventional sources. Thus, an opportunity is now available to maximize the use of solar energy and gain the improved efficiencies possible with CHPs to deploy PV + battery + CHP systems throughout the U.S. The aim of this study is to determine the technical viability of such systems by simulating PV + battery + CHP hybrid systems deployed in three representative regions in the U.S., using the Hybrid Optimization Model for Electric Renewable (HOMER) Pro Microgrid Analysis tool. The results show that the electricity generated by each component of the hybrid system can be coupled to fulfill the residential load demand. A sensitivity analysis of these hybrid off grid systems is carried out as a function capacity factor of both the PV and CHP units. The

Can photovoltaic replace nuclear?

International Nuclear Information System (INIS)

2017-01-01

As the French law on energy transition for a green growth predicts that one third of nuclear energy production is to be replaced by renewable energies (wind and solar) by 2025, and while the ADEME proposes a 100 per cent renewable scenario for 2050, this paper proposes a brief analysis of the replacement of nuclear energy by solar photovoltaic energy. It presents and discusses some characteristics of photovoltaic production: production level during a typical day for each month (a noticeable lower production in December), evolution of monthly production during a year, evolution of the rate between nuclear and photovoltaic production. A cost assessment is then proposed for energy storage and for energy production, and a minimum cost of replacement of nuclear by photovoltaic is assessed. The seasonal effect is outlined, as well as the latitude effect. Finally, the authors outline the huge cost of such a replacement, and consider that public support to new photovoltaic installations without an at least daily storage mean should be cancelled

Performance of Partially Covered N Number of Photovoltaic Thermal (PVT) - Compound Parabolic Concentrator (CPC) Series Connected Water Heating System

OpenAIRE

Rohit Tripathi; Sumit Tiwari; G. N. Tiwari

2016-01-01

In present study, an approach is adopted where photovoltaic thermal flat plate collector is integrated with compound parabolic concentrator. Analytical expression of temperature dependent electrical efficiency of N number of partially covered Photovoltaic Thermal (PVT) - Compound Parabolic Concentrator (CPC) water collector connected in series has been derived with the help of basic thermal energy balance equations. Analysis has been carried for winter weather condition at Delhi location, Ind...

Organic photovoltaics. Technology and market

International Nuclear Information System (INIS)

Brabec, Christoph J.

2004-01-01

Organic photovoltaics has come into the international research focus during the past three years. Up to now main efforts have focused on the improvement of the solar conversion efficiency, and in recent efforts 5% white light efficiencies on the device level have been realized. Despite this in comparison to inorganic technologies low efficiency, organic photovoltaics is evaluated as one of the future key technologies opening up completely new applications and markets for photovoltaics. The key property which makes organic photovoltaics so attractive is the potential of reel to reel processing on low cost substrates with standard coating and printing processes. In this contribution we discuss the economical and technical production aspects for organic photovoltaics

Roof Photovoltaic Test Facility

Data.gov (United States)

Federal Laboratory Consortium — In order to accurately predict the annual energy production of photovoltaic systems for any given geographical location, building orientation, and photovoltaic cell...

Optical properties of Sb(Se,Te)I and photovoltaic applications

Energy Technology Data Exchange (ETDEWEB)

Tablero, C., E-mail: ctablero@etsit.upm.es

2016-09-05

SbXI (X = Se, Te) are ferroelectric semiconductors that allow a variety of applications including optoelectronic and photovoltaic applications. An analysis of the optical properties is carried out starting from first-principles density-functional theory with orbital-dependent one-electron potentials. To go into the contributions to the optical properties more deeply, the absorption coefficients have been split into inter- and intra-species contributions and into atomic angular momentum contributions. The optical results are used to evaluate the efficiencies when this material is used to absorb sunlight at several sunlight concentrations and the usual radiative and the ferroelectric photovoltaic mechanisms. The results indicate their applicability in photovoltaic devices as absorbent of the solar spectrum with high conversion efficiency. - Highlights: • The SbXI (X = Se, Te) are ferroelectric semiconductors with a high optical absorption. • The absorption coefficients have been split into different contributions to understand the cause of the high absorption. • Using the first-principles results the maximum efficiency of this photovoltaic absorber material has been estimated. • The efficiency of this compound is near the maximum efficiency for single-gap solar cells even using small-width devices. • The coexistence of the R-PV and R-PV effects has been evaluated.

Performance and costs of a roof-sized PV/thermal array combined with a ground coupled heat pump

NARCIS (Netherlands)

Bakker, M.; Zondag, H.A.

2005-01-01

A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. Hence, PVT panels are an alternative for a combination of separate PV panels and solar thermal collectors. A promising system concept,

US Photovoltaic Patents, 1988--1990

Energy Technology Data Exchange (ETDEWEB)

1991-12-01

This document contains US patents on terrestrial photovoltaic (PV) power applications, including systems, components, and materials, as well as manufacturing and support functions. The patent entries in this document were issued from 1988 through 1990. The entries were located by searching USPA, the data base of the US Patent Office. The final search retrieved all patents under the class ``Batteries, Thermoelectric and Photoelectric`` and the subclasses ``Photoelectric,`` ``Testing,`` and ``Applications.`` The search also located patents that contained the words ``photovoltaic(s)`` or ``solar cell(s)`` and their derivatives. A manual search of the patents in the Solar Energy Research Institute (SERI) patent file augmented the data base search. After the initial list was compiled, most of the patents on the following subjects were excluded: space photovoltaic technology, use of the photovoltaic effect for detectors and subjects only peripherally concerned with photovoltaics. Some patents on these three subjects were included when it appeared that those inventions might be of use in terrestrial PV power technologies.

Solar technology assessment project. Volume 6: Photovoltaic technology assessment

Science.gov (United States)

Backus, C. E.

1981-04-01

Industrial production of photovoltaic systems and volume of sales are reviewed. Low cost silicon production techniques are reviewed, including the Czochralski process, heat exchange method, edge defined film fed growth, dentritic web growth, and silicon on ceramic process. Semicrystalline silicon, amorphous silicon, and low cost poly-silicon are discussed as well as advanced materials and concentrator systems. Balance of system components beyond those needed to manufacture the solar panels are included. Nontechnical factors are assessed. The 1986 system cost goals are briefly reviewed.

The Semitransparent Photovoltaic Films for Mediterranean Greenhouse: A New Sustainable Technology

Directory of Open Access Journals (Sweden)

Alvaro Marucci

2012-01-01

Full Text Available Mediterranean countries offer very favorable climatic conditions for growing plants in a protected environment: as a matter of fact, the high solar radiation allows the use of greenhouses with simple structures, covered with plastic film and without fixed installations for winter heating. They are called “Mediterranean greenhouses” and are totally different from those in Central and Northern Europe. In the photovoltaic greenhouses, the cover on the pitch facing south is usually replaced by very opaque panels. However, this solution compromises the possibility to grow plants in covered and protected environments since solar radiation availability is limited and strongly nonuniform. In order to overcome this problem, semitransparent photovoltaic materials can be used to let the solar energy, necessary for plant growth, pass into the green house. The aim of this research is to analyze the radiometric properties of innovative semitransparent flexible photovoltaic materials in order to evaluate their performances in comparison with materials commonly used in the coverage of the greenhouses. Particular attention is paid to the transmittance of these materials in the visible range and in the long wave infrared for the achievement of greenhouse effect.

Solar Photovoltaic Energy.

Science.gov (United States)

Ehrenreich, Henry; Martin, John H.

1979-01-01

The goals of solar photovoltaic technology in contributing to America's future energy needs are presented in this study conducted by the American Physical Society. Although the time needed for photovoltaics to become popular is several decades away, according to the author, short-range applications are given. (Author/SA)

Organic photovoltaics

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Within the International Conference and Exhibition at 16th September,2010 at the Maritim Hotel (Wuerzburg, Federal Republic of Germany) the following lectures were held: (1) History of Organic Photovoltaics (Niyazi Serdar Sariciftci); (2) PV Activities at the ZAE Bayern (Vladimir Dyakonov); (3) Progress in Solid State DSC (Peter Erk); (4) Polymer Semiconductors for OPV (Mats Andersson); (5) Fullerene Derivative N-Types in Organic Solar Cells (David Kronholm); (6) Modelling Charge-Transport in Organic Photovoltaic Materials (Jenny Nelson); (7) Multi Junction Modules R and D Status and Outlook (Paul Blom); (8) Imaging Technologies for Organic Solar Cells (Jonas Bachmann); (9) Production of Multi-junction Organic Photovoltaic Cells and Modules (Martin Pfeiffer); (10) Upscaling of Polymer Solar Cell Fabrication Using Full Roll-to-roll Processing (Frederik Christian Krebs); (11) Industrial Aspects and Large Scale OPV Production (Jens Hauch).

Batteryless photovoltaic reverse-osmosis desalination system

Energy Technology Data Exchange (ETDEWEB)

Thomson, M.; Miranda, M.; Gwillim, J.; Rowbottom, A.; Draisey, I.

2001-07-01

The aim of this project was to design an efficient cost-effective batteryless photovoltaic-powered seawater reverse-osmosis desalination system, to deliver in the order of 3 m{sup 3} of fresh drinking water per day. The desalination of seawater to produce fresh drinking water is extremely valuable on islands and in coastal regions wherever natural freshwater is scarce. Existing small-scale desalination equipment, suitable for areas of medium and low population density, often requires a copious and constant supply of energy, either electricity or diesel. If supply of these fuels is expensive or insecure, but the area has a good solar resource, the use of photovoltaic power is an attractive option. Existing demonstrations of photovoltaic-powered desalination generally employ lead-acid batteries, which allow the equipment to operate at a constant flow, but are notoriously problematic in practice. The system developed in this project runs at variable flow, enabling it to make efficient use of the naturally varying solar resource, without need of batteries. In a sense, the freshwater tank is providing the energy storage. In this project, we have reviewed the merits of a wide variety of reverse-osmosis system configurations and component options. We have completed extensive in-house testing and characterisation of major hardware components and used the results to construct detailed software models. Using these, we have designed a system that meets the above project aim, and we have predicted its performance in detail. Our designs show that a system costing 23,055 pounds stirling will produce 1424 m{sup 3} of fresh drinking water annually - an average of just over 3.9 m{sup 3}/day. The system has no fuel costs and no batteries. The overall cost of water, including full maintenance, is 2.00 pounds stirling per m{sup 3}. The energy consumption (photovoltaic-electricity) is typically between 3.2 and 3.7 kWh/m{sup 3} depending on the solar irradiance and feed water

Intermediate photovoltaic system application experiment operational performance report. Volume 4, for Beverly High School, Beverly, MA

Energy Technology Data Exchange (ETDEWEB)

1982-01-01

Performance data are presented for the months of November and December, 1981 for a photovoltaic power supply at a Massachusetts school building. The data include: monthly and daily electrical energy produced; monthly and daily solar energy received; monthly and daily array efficiency; energy produced as a function of power level, voltage, cell temperature, and hour of the day; input, output, and efficiency of two power conditioner units and for the total power conditioning system; energy supplied by the photovoltaic system to the load during each day and month; photovoltaic system efficiency; capacity factor; daily system availability; monthly and hourly insolation; heating and cooling degree days; number of freeze/thaw cycles per month; monthly and hourly ambient temperature; monthly and hourly wind speed; wind direction distribution; hourly cell temperature; and data acquisition mode and recording interval plot. (LEW)

Enlarging photovoltaic effect: combination of classic photoelectric and ferroelectric photovoltaic effects.

Science.gov (United States)

Zhang, Jingjiao; Su, Xiaodong; Shen, Mingrong; Dai, Zhihua; Zhang, Lingjun; He, Xiyun; Cheng, Wenxiu; Cao, Mengyu; Zou, Guifu

2013-01-01

Converting light energy to electrical energy in photovoltaic devices relies on the photogenerated electrons and holes separated by the built-in potential in semiconductors. Photo-excited electrons in metal electrodes are usually not considered in this process. Here, we report an enhanced photovoltaic effect in the ferroelectric lanthanum-modified lead zirconate titanate (PLZT) by using low work function metals as the electrodes. We believe that electrons in the metal with low work function could be photo-emitted into PLZT and form the dominant photocurrent in our devices. Under AM1.5 (100 mW/cm²) illumination, the short-circuit current and open-circuit voltage of Mg/PLZT/ITO are about 150 and 2 times of those of Pt/PLZT/ITO, respectively. The photovoltaic response of PLZT capacitor was expanded from ultraviolet to visible spectra, and it may have important impact on design and fabrication of high performance photovoltaic devices based on ferroelectric materials.

Photovoltaic technologies

OpenAIRE

Bagnall, Darren M; Boreland, Matt

2008-01-01

Photovoltaics is already a billion dollar industry. It is experiencing rapid growth as concerns over fuel supplies and carbon emissions mean that governments and individuals are increasingly prepared to ignore its current high costs. It will become truly mainstream when its costs are comparable to other energy sources. At the moment, it is around four times too expensive for competitive commercial production. Three generations of photovoltaics have been envisaged that will take solar power in...

Photovoltaic barometer

International Nuclear Information System (INIS)

Anon.

2009-01-01

spain and Germany set the pace for the world photovoltaic market in 2008, which grew to more than twice its 2007 size. The European Union continued to drive photocell installation with an additional 4 592.3 MWp in 2008, or 151.6% growth over 2007. However, European growth prospects for the photovoltaic market in 2009 are being dampened by the global financial crisis and the scheduled slow-down of the Spanish market. (author)

Thin Film Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Zweibel, K.

1998-11-19

The motivation to develop thin film technologies dates back to the inception of photovoltaics. It is an idea based on achieving truly low-cost photovoltaics appropriate for mass production and energy significant markets. The key to the idea is the use of pennies worth of active materials. Since sunlight carries relatively little energy in comparison with combustion-based energy sources, photovoltaic (PV) modules must be cheap to produce energy that can be competitive. Thin films are presumed to be the answer to that low-cost requirement. But how cheap do they have to be? The following is an oversimplified analysis that allows some insight into this question.

太阳能光电热系统换热器性能实验研究%Experimental Research on Performance of Solar Energy Photovoltaic/thermal System in Heat Exchanger

Institute of Scientific and Technical Information of China (English)

庄春龙; 杨小凤; 张洪宇; 张连山

2013-01-01

A new kind of semicircle pipe⁃type stainless steel heat exchanger has been designed for solar energy photovoltaic/thermal(PV/T)application system. The PV/T characteristics of the PV/T module utilized in Chongqing area are analyzed through the comparative experiment of new kind of PV/T heat collection module with PV module system. The results show that the battery output power of PV/T system made of the semicircle pipe⁃type stainless steel heat exchanger is larger than that of photo⁃thermal (PV)system 26.48%,and the efficiency of radiant heat utility is larger than that of PV system about 23.70%under sunshiny cir⁃cumstance. The general energy efficiency(photovoltaic/thermal+thermal)of the PV/T reaches 25.70%. The new semicircle pipe⁃type heat exchanger increases the thermal area and raises the thermal efficiency,which provides the instructive reference to the inte⁃grative application of the solar photovoltaic/thermal in the feeblish solar radiation area like Chongqing.%　　设计了新型半圆管形式的不锈钢板式换热器，对其作为太阳能光电热综合利用一体化系统集热组件的性能进行实验研究。通过新型集热光电热组件及光电组件系统的对比实验，研究该光电热组件在重庆地区夏季应用情况，分析其光电和光热特性。结果表明：在以晴朗为主的天气，半圆管形式的不锈钢板式光电热组件电热系统的电热性能与光电组件系统的相比较，前者的太阳能电池输出功率提高约26.48%，热利用效率提高23.70%以上，新型半圆管形式的光电热组件整体光电热（光电+光热）综合效率可达到25.70%，有效提高了光电热系统的综合效率。新型半圆管形式不锈钢板式换热器的换热面积增大，提高了换热效率，为太阳能光电热综合利用一体化系统在重庆等太阳辐射强度较小地区的应用提供了参考。

The effect of donor layer thickness on the power conversion efficiency of organic photovoltaic devices fabricated with a double small-molecular layer

International Nuclear Information System (INIS)

Lee, Su-Hwan; Kim, Dal-Ho; Shim, Tae-Hun; Park, Jea-Gun

2009-01-01

In organic photovoltaic (OPV) devices fabricated with a double small-molecular layer, the power conversion efficiency strongly depends on the thickness of the organic donor layer (here, copper phthalocyanine). In other words, the power conversion efficiency increases with the donor layer thickness up to a specific thickness (∼12.7 nm) and then decreases beyond that thickness. This trend is associated with the light absorption and carrier transport resistance of the small-molecular donor layer, both of which strongly depend on the layer thickness. Experimental and calculated results showed that the short-circuit current due to light absorption increased with the donor layer thickness, while that due to current through the donor layer decreased with 1/R. Since the total short-circuit current is the product of the light absorption current and current through the donor layer, there is a trade-off, and the maximum power conversion efficiency occurs at a specific organic donor layer thickness (e.g. ∼12.7 nm in this experiment).

ZnO-based nanocrystalline powders with applications in hybrid photovoltaic cells

Energy Technology Data Exchange (ETDEWEB)

Damonte, L.C. [Dto. De Fisica, UNLP, IFLP-CCT-CONICET, C.C.67 (1900) La Plata (Argentina); Dto. De Fisica Aplicada, Universidad Politecnica de Valencia, Cami de Vera s/n (46071) Valencia (Spain); Donderis, V. [Dto. De Ingenieria Electrica, Universidad Politecnica de Valencia, Cami de Vera s/n (46071) Valencia (Spain); Ferrari, S.; Meyer, M. [Dto. De Fisica, UNLP, IFLP-CCT-CONICET, C.C.67 (1900) La Plata (Argentina); Orozco, J. [Dto. de Ingenieria Mecanica y Materiales, Universidad Politecnica de Valencia, Cami de Vera s/n (46071) Valencia (Spain); Hernandez-Fenollosa, M.A. [Dto. De Fisica Aplicada, Universidad Politecnica de Valencia, Cami de Vera s/n (46071) Valencia (Spain)

2010-06-15

In recent years there has been a growing interest in the development of hybrid photovoltaic cells consisting of new materials, such as devices based on the combination of a wide gap semiconductor and an organic dye (dye-sensitized solar cells, DSSC). In this paper we obtain nano-zinc oxide particles whose optical and electrical properties have been modified by the presence of small amounts of Al or In acting as dopants. The aim of this study is to improve the compatibility of each of the compounds present in the photovoltaic solar cell. The knowledge gained will provide input to guide the processes in the manufacture of hybrid solar cells. (author)

Solar photovoltaics for development applications

Energy Technology Data Exchange (ETDEWEB)

Shepperd, L.W. [Florida Solar Energy Center, Cape Canaveral, FL (United States); Richards, E.H. [Sandia National Labs., Albuquerque, NM (United States)

1993-08-01

This document introduces photovoltaic technology to individuals and groups specializing in development activities. Examples of actual installations illustrate the many services supplied by photovoltaic systems in development applications, including water pumping, lighting, health care, refrigeration, communications, and a variety of productive uses. The various aspects of the technology are explored to help potential users evaluate whether photovoltaics can assist them in achieving their organizational goals. Basic system design, financing techniques, and the importance of infrastructure are included, along with additional sources of information and major US photovoltaic system suppliers.

Photovoltaic energy systems. Program summary

Energy Technology Data Exchange (ETDEWEB)

None

1982-01-01

The ongoing research, development, and demonstration efforts of the Photovoltaics Program are highlighted and each of the US Department of Energy's current photovoltaics projects initiated or renewed during fiscal year 1981 is described, including its title, directing organization, project engineer, contractor, principal investigator, contract period, funding, and objectives. The Photovoltaics Program is briefly summarized, including the history and organization and highlights of the research and development and of planning, assessment, and integration. Also summarized is the Federal Photovoltaic Utilization Program. An exhaustive bibliography is included. (LEW)

Evaluation of the communal Photovoltaic system with distribution nets in La Venturosa, Colombia

International Nuclear Information System (INIS)

Castillo C, J.J; Romero R, L.C.

1997-01-01

A communal Photovoltaic minigrid grid system had been operating for about two years in La Venturosa, a small Village located at the Easter Plains of Colombia. The Institute of Nuclear Sciences and Alternative Energies, INEA, had been evaluating this system for about a year of operation in order to measure performance, level of satisfaction in users and sustain ability of the project. The results of this evaluation concluded that the option of communal minigrid Photovoltaic systems represents a good alternative, but that the human element can affect the sustain ability for this type of projects

Study of an improved integrated collector-storage solar water heater combined with the photovoltaic cells

International Nuclear Information System (INIS)

Ziapour, Behrooz M.; Palideh, Vahid; Mohammadnia, Ali

2014-01-01

Highlights: • Simulation of an enhanced ICSSWH system combined with PV panel was conducted. • The present model dose not uses any photovoltaic driven water pump. • High packing factor and tank water mass are caused to high PVT system efficiency. • Larger area of the collector is resulted to lower total PVT system efficiency. - Abstract: A photovoltaic–thermal (PVT) module is a combination of a photovoltaic (PV) panel and a thermal collector for co-generation of heat and electricity. An integrated collector-storage solar water heater (ICSSWH) system, due to its simple and compact structure, offers a promising approach for the solar water heating in the varied climates. The combination of the ICSSWH system with a PV solar system has not been reported. In this paper, simulation of an enhanced ICSSWH system combined with the PV panel has been conducted. The proposed design acts passive. Therefore, it does not use any photovoltaic driven water pump to maintain a flow of water inside the collector. The effects of the solar cell packing factor, the tank water mass and the collector area on the performance of the present PVT system have been investigated. The simulation results showed that the high solar cell packing factor and the tank water mass are caused to the high total PVT system efficiency. Also, larger area of the collector is resulted to lower total PVT system efficiency

Heat pipe applications for future Air Force spacecraft

International Nuclear Information System (INIS)

Mahefkey, T.; Barthelemy, R.R.

1980-01-01

This paper summarizes the envisioned, future usage of high and low temperature heat pipes in advanced Air Force spacecraft. Thermal control requirements for a variety of communications, surveillance, and space defense missions are forecast. Thermal design constraints implied by survivability to potential weapons effects are outlined. Applications of heat pipes to meet potential low and high power spacecraft mission requirements and envisioned design constraints are suggested. A brief summary of past Air Force sponsored heat pipe development efforts is presented and directions for future development outlined, including those applicable to advanced photovoltaic and nuclear power subsystem applications of heat pipes

Thin film heterojunction photovoltaic cells and methods of making the same

Science.gov (United States)

Basol, Bulent M.; Tseng, Eric S.; Rod, Robert L.

1983-06-14

A method of fabricating a thin film heterojunction photovoltaic cell which comprises depositing a film of a near intrinsic or n-type semiconductor compound formed of at least one of the metal elements of Class II B of the Periodic Table of Elements and at least tellurium and then heating said film at a temperature between about 250.degree. C. and 500.degree. C. for a time sufficient to convert said film to a suitably low resistivity p-type semiconductor compound. Such film may be deposited initially on the surface of an n-type semiconductor substrate. Alternatively, there may be deposited on the converted film a layer of n-type semiconductor compound different from the film semiconductor compound. The resulting photovoltaic cell exhibits a substantially increased power output over similar cells not subjected to the method of the present invention.

Photovoltaic Bias Generator

Science.gov (United States)

2018-02-01

Department of the Army position unless so designated by other authorized documents. Citation of manufacturer’s or trade names does not constitute an... Interior view of the photovoltaic bias generator showing wrapped-wire side of circuit board...3 Fig. 4 Interior view of the photovoltaic bias generator showing component side of circuit board

Experimental study on direct-contact liquid film cooling simulated dense-array solar cells in high concentrating photovoltaic system

International Nuclear Information System (INIS)

Wang, Yiping; Shi, Xusheng; Huang, Qunwu; Cui, Yong; Kang, Xue

2017-01-01

Highlights: • Direct-contact liquid film cooling dense-array solar cells was first proposed. • Average temperature was controlled well below 80 °C. • The maximum temperature difference was less than 10 °C. • The heat transfer coefficient reached up to 11.91 kW/(m"2·K) under 589X. - Abstract: This paper presented a new method of cooling dense-array solar cells in high concentrating photovoltaic system by direct-contact liquid film, and water was used as working fluid. An electric heating plate was designed to simulate the dense-array solar cells in high concentrating photovoltaic system. The input power of electric heating plate simulated the concentration ratios. By heat transfer experiments, the effect of water temperatures and flow rates on heat transfer performance was investigated. The results indicated that: the average temperature of simulated solar cells was controlled well below 80 °C under water temperature of 30 °C and flow rate of 300 L/h when concentration ratio ranged between 300X and 600X. The maximum temperature difference among temperature measurement points was less than 10 °C, which showed the temperature distribution was well uniform. The heat transfer coefficient reached up to 11.91 kW/(m"2·K) under concentration ratio of 589X. To improve heat transfer performance and obtain low average temperature of dense-array solar cells, lower water temperature and suitable water flow rate are preferred.

CISBAT 2007 - Solar collectors (heat and electricity)

International Nuclear Information System (INIS)

2007-01-01

This is the third part of the proceedings of the 2007 CISBAT conference on Renewables in a changing climate, held in Lausanne, Switzerland. On the subject of Building and urban integration of renewables the following oral contributions are summarised: 'Facade integration of solar thermal collectors: present and future', 'Long term experiences with a versatile PV in roof system', 'Development of a design and performance prediction tool for the ground source heat pump and underground thermal storage system', 'Hygrothermal performance of earth-to-air heat exchanger: long-term data evaluation and short-term simulation' as well as 'The real cost of heating your home: a comparative assessment of home energy systems with external costs'. Poster-sessions on the subject include 'Central solar heating plants with seasonal heat storage', 'Analysis of forced convection for evaporative air flow and heat transfer in PV cooling channels', 'Renewable energy technology in Mali: constraints and options for a sustainable development', 'Effect of duct width in ducted photovoltaic facades', 'Design and actual measurement of a ground source heat pump system using steel foundation piles as ground heat exchangers', 'Development of an integrated water-water heat pump unit for low energy house and its application', 'PV effect in multilayer cells and blending of fullerene/poly (3-hexylthiophene) and phthalocyanine having NIR charge transfer absorption band', 'CdTe photovoltaic systems - an alternative energetic', 'Integration of renewable energy sources in a town, examples in Grenoble', 'A prospective analysis method for the conception of solar integration solutions in buildings' and 'Energy and aesthetic improvements for building integration of cost effective solar energy systems'. Further groups of presentations at the conference are reported on in separate database records. An index of authors completes the proceedings

Transparent contacts for stacked compound photovoltaic cells

Science.gov (United States)

Tauke-Pedretti, Anna; Cederberg, Jeffrey; Nielson, Gregory N.; Okandan, Murat; Cruz-Campa, Jose Luis

2016-11-29

A microsystems-enabled multi-junction photovoltaic (MEM-PV) cell includes a first photovoltaic cell having a first junction, the first photovoltaic cell including a first semiconductor material employed to form the first junction, the first semiconductor material having a first bandgap. The MEM-PV cell also includes a second photovoltaic cell comprising a second junction. The second photovoltaic cell comprises a second semiconductor material employed to form the second junction, the second semiconductor material having a second bandgap that is less than the first bandgap, the second photovoltaic cell further comprising a first contact layer disposed between the first junction of the first photovoltaic cell and the second junction of the second photovoltaic cell, the first contact layer composed of a third semiconductor material having a third bandgap, the third bandgap being greater than or equal to the first bandgap.

Photovoltaic array mounting apparatus, systems, and methods

Science.gov (United States)

West, Jack Raymond; Atchley, Brian; Hudson, Tyrus Hawkes; Johansen, Emil

2016-01-05

A photovoltaic array, including: (a) supports laid out on a surface in rows and columns; (b) photovoltaic modules positioned on top of the supports; and (c) fasteners connecting the photovoltaic modules to the supports, wherein the supports have an upper pedestal surface and a lower pedestal surface such that the photovoltaic modules are positioned at a non-horizontal angle when edges of the photovoltaic modules are positioned on top of the upper and lower pedestal surfaces, and wherein a portion of the fasteners rotate to lock the photovoltaic modules onto the supports.

Small heat shock proteins can release light dependence of tobacco seed during germination.

Science.gov (United States)

Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia; Hong, Choo Bong

2015-03-01

Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. © 2015 American Society of Plant Biologists. All Rights Reserved.

An Advanced Photovoltaic Array Regulator Module

Science.gov (United States)

Button, Robert M.

1996-01-01

Current trends in satellite design are focused on developing small, reliable, and inexpensive spacecraft. To that end, a modular power management and distribution system is proposed which will help transition the aerospace industry towards an assembly line approach to building spacecraft. The modular system is based on an innovative DC voltage boost converter called the Series Connected Boost Unit (SCBU). The SCBU uses any isolating DC-DC converter and adds a unique series connection. This simple modification provides the SCBU topology with many advantages over existing boost converters. Efficiencies of 94-98%, power densities above 1,000 W/kg, and inherent fault tolerance are just a few of the characteristics presented. Limitations of the SCBU technology are presented, and it is shown that the SCBU makes an ideal photovoltaic an-ay regulator. A set of photovoltaic power system requirements are presented that can be applied to almost any low Earth orbit satellite. Finally, a modular design based on the series connected boost unit is outlined and functional descriptions of the components are given.

International market assessment of stand-alone photovoltaic power systems for cottage industry applications

Science.gov (United States)

Philippi, T. M.

1981-01-01

The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

International market assessment of stand-alone photovoltaic power systems for cottage industry applications

Science.gov (United States)

Philippi, T. M.

1981-11-01

The final result of an international assessment of the market for stand-alone photovoltaic systems in cottage industry applications is reported. Nonindustrialized countries without centrally planned economies were considered. Cottage industries were defined as small rural manufacturers, employing less than 50 people, producing consumer and simple products. The data to support this analysis were obtained from secondary and expert sources in the U.S. and in-country field investigations of the Philippines and Mexico. The near-term market for photovoltaics for rural cottage industry applications appears to be limited to demonstration projects and pilot programs, based on an in-depth study of the nature of cottage industry, its role in the rural economy, the electric energy requirements of cottage industry, and a financial analysis of stand-alone photovoltaic systems as compared to their most viable competitor, diesel driven generators. Photovoltaics are shown to be a better long-term option only for very low power requirements. Some of these uses would include clay mixers, grinders, centrifuges, lathes, power saws and lighting of a workshop.

Daytime Solar Heating of Photovoltaic Arrays in Low Density Plasmas

Science.gov (United States)

Galofaro, J.; Vayner, B.; Ferguson, D.

2003-01-01

The purpose of the current work is to determine the out-gassing rate of H2O molecules for a solar array placed under daytime solar heating (full sunlight) conditions typically encountered in a Low Earth Orbital (LEO) environment. Arc rates are established for individual arrays held at 14 C and are used as a baseline for future comparisons. Radiated thermal solar flux incident to the array is simulated by mounting a stainless steel panel equipped with resistive heating elements several centimeters behind the array. A thermal plot of the heater plate temperature and the array temperature as a function of heating time is then obtained. A mass spectrometer is used to record the levels of partial pressure of water vapor in the test chamber after each of the 5 heating/cooling cycles. Each of the heating cycles was set to time duration of 40 minutes to simulate the daytime solar heat flux to the array over a single orbit. Finally the array is cooled back to ambient temperature after 5 complete cycles and the arc rates of the solar arrays is retested. A comparison of the various data is presented with rather some unexpected results.

Crystal structure of a small heat-shock protein from Xylella fastidiosa reveals a distinct high-order structure.

Science.gov (United States)

Fonseca, Emanuella Maria Barreto; Scorsato, Valéria; Dos Santos, Marcelo Leite; Júnior, Atilio Tomazini; Tada, Susely Ferraz Siqueira; Dos Santos, Clelton Aparecido; de Toledo, Marcelo Augusto Szymanski; de Souza, Anete Pereira; Polikarpov, Igor; Aparicio, Ricardo

2017-04-01

Citrus variegated chlorosis is a disease that attacks economically important citrus plantations and is caused by the plant-pathogenic bacterium Xylella fastidiosa. In this work, the structure of a small heat-shock protein from X. fastidiosa (XfsHSP17.9) is reported. The high-order structures of small heat-shock proteins from other organisms are arranged in the forms of double-disc, hollow-sphere or spherical assemblies. Unexpectedly, the structure reported here reveals a high-order architecture forming a nearly square cavity.

Evaluation of Hybrid Power Plants using Biomass, Photovoltaics and Steam Electrolysis for Hydrogen and Power Generation

Science.gov (United States)

Petrakopoulou, F.; Sanz, J.

2014-12-01

Steam electrolysis is a promising process of large-scale centralized hydrogen production, while it is also considered an excellent option for the efficient use of renewable solar and geothermal energy resources. This work studies the operation of an intermediate temperature steam electrolyzer (ITSE) and its incorporation into hybrid power plants that include biomass combustion and photovoltaic panels (PV). The plants generate both electricity and hydrogen. The reference -biomass- power plant and four variations of a hybrid biomass-PV incorporating the reference biomass plant and the ITSE are simulated and evaluated using exergetic analysis. The variations of the hybrid power plants are associated with (1) the air recirculation from the electrolyzer to the biomass power plant, (2) the elimination of the sweep gas of the electrolyzer, (3) the replacement of two electric heaters with gas/gas heat exchangers, and (4) the replacement two heat exchangers of the reference electrolyzer unit with one heat exchanger that uses steam from the biomass power plant. In all cases, 60% of the electricity required in the electrolyzer is covered by the biomass plant and 40% by the photovoltaic panels. When comparing the hybrid plants with the reference biomass power plant that has identical operation and structure as that incorporated in the hybrid plants, we observe an efficiency decrease that varies depending on the scenario. The efficiency decrease stems mainly from the low effectiveness of the photovoltaic panels (14.4%). When comparing the hybrid scenarios, we see that the elimination of the sweep gas decreases the power consumption due to the elimination of the compressor used to cover the pressure losses of the filter, the heat exchangers and the electrolyzer. Nevertheless, if the sweep gas is used to preheat the air entering the boiler of the biomass power plant, the efficiency of the plant increases. When replacing the electric heaters with gas-gas heat exchangers, the

Renewable energy distributed power system with photovoltaic/ thermal and bio gas power generators

International Nuclear Information System (INIS)

Haider, M.U.; Rehman, S.U.

2011-01-01

The energy shortage and environmental pollution is becoming an important problem in these days. Hence it is very much important to use renewable power technologies to get rid of these problems. The important renewable energy sources are Bio-Energy, Wind Energy, Hydrogen Energy, Tide Energy, Terrestrial Heat Energy, Solar Energy, Thermal Energy and so on. Pakistan is rich in all these aspects particularly in Solar and Thermal Energies. In major areas of Pakistan like in South Punjab, Sind and Baluchistan the weather condition are very friendly for these types of Renewable Energies. In these areas Solar Energy can be utilized by solar panels in conjunction with thermal panels. The Photovoltaic cells are used to convert Solar Energy directly to Electrical Energy and thermal panels can be uses to convert solar energy into heat energy and this heat energy will be used to drive some turbine to get Electrical Energy. The Solar Energy can be absorbed more efficiently by any given area of Solar Panel if these two technologies can be combined in such a way that they can work together. The first part of this paper shows that how these technologies can be combined. Furthermore it is known to all that photovoltaic/thermal panels depend entirely on weather conditions. So in order to maintain constant power a biogas generator is used in conjunction with these. (author)

Low-Dimensional Nanomaterials as Active Layer Components in Thin-Film Photovoltaics

Science.gov (United States)

Shastry, Tejas Attreya

to result in record breaking performance in a carbon nanotube solar cell, and subsequent chapters study the mechanisms behind charge transfer in the polychiral carbon nanotube / fullerene solar cell. Further processing advances, chiral distribution tailoring, and solvent additives are shown to enable more uniform and larger area carbon nanotube solar cells while maintaining record-breaking performance. In order to increase overall photovoltaic performance of a carbon nanotube active layer solar cell, this dissertation also demonstrates a ternary polymer-carbon nanotube-small molecule photovoltaic with high efficiency and stability enabled by the nanomaterial. Finally, the use of the two-dimensional metal dichalcogenide molybdenum disulfide as a photovoltaic material is explored in an ultrathin solar cell with higher efficiency per thickness than leading organic and inorganic thin-film photovoltaics. Overall, this work demonstrates breakthroughs in utilizing low-dimensional nanomaterials as active layer components in photovoltaics and will inform ongoing research in making ultrathin, stable, efficient solar cells.

Photovoltaics in Poland

International Nuclear Information System (INIS)

Pietruszko, Stanislaw M.

2003-01-01

The legislative framework and financing possibilities for photovoltaics (PV) in Poland are presented. Barriers that exist or can be encountered in implementing PV technology in Poland are identified. This paper also discusses future prospects and possibilities for developing photovoltaics in Poland. Finally, the paper suggests ways to promote, disseminate, and deploy PV technology in Poland. (Author)

Clean electricity from photovoltaics

CERN Document Server

Green, Martin A

2015-01-01

The second edition of Clean Electricity from Photovoltaics , first published in 2001, provides an updated account of the underlying science, technology and market prospects for photovoltaics. All areas have advanced considerably in the decade since the first edition was published, which include: multi-crystalline silicon cell efficiencies having made impressive advances, thin-film CdTe cells having established a decisive market presence, and organic photovoltaics holding out the prospect of economical large-scale power production. Contents: The Past and Present (M D Archer); Limits to Photovol

Economical and environmental analysis of thermal and photovoltaic solar energy as source of heat for industrial processes

Science.gov (United States)

Pérez-Aparicio, Elena; Lillo-Bravo, Isidoro; Moreno-Tejera, Sara; Silva-Pérez, Manuel

2017-06-01

Thermal energy for industrial processes can be generated using thermal (ST) or photovoltaic (PV) solar energy. ST energy has traditionally been the most favorable option due to its cost and efficiency. Current costs and efficiencies values make the PV solar energy become an alternative to ST energy as supplier of industrial process heat. The aim of this study is to provide a useful tool to decide in each case which option is economically and environmentally the most suitable alternative. The methodology used to compare ST and PV systems is based on the calculation of the levelized cost of energy (LCOE) and greenhouse gas emissions (GHG) avoided by using renewable technologies instead of conventional sources of energy. In both cases, these calculations depend on costs and efficiencies associated with ST or PV systems and the conversion factor from thermal or electrical energy to GHG. To make these calculations, a series of hypotheses are assumed related to consumer and energy prices, operation, maintenance and replacement costs, lifetime of the system or working temperature of the industrial process. This study applies the methodology at five different sites which have been selected taking into account their radiometric and meteorological characteristics. In the case of ST energy three technologies are taken into account, compound parabolic concentrator (CPC), linear Fresnel collector (LFC) and parabolic trough collector (PTC). The PV option includes two ways of use of generated electricity, an electrical resistance or a combination of an electrical resistance and a heat pump (HP). Current values of costs and efficiencies make ST system remains as the most favorable option. These parameters may vary significantly over time. The evolution of these parameters may convert PV systems into the most favorable option for particular applications.

Final Environmental Assessment for Decommissioning and Demolition of the Central Heat Plant, GHLN 09-1010B F. E. Warren Air Force Base, Wyoming

Science.gov (United States)

2012-06-01

could either be accomplished by installing a solar heating panel on the roof of each of the 104 buildings or having a solar photovoltaic array...Prior to 1981 , ACMs were used extensively in plaster, wall board, joint compound, felt material , roofing material , floor tile , mastic, piping...5 5.4. Alternative D-lnstall Solar Heating Panels or Solar Photovoltaic Array ......................... 5 5.5. Alternative E

Intermediate photovoltaic system application experiment operational performance report. Volume 7. Beverly High School, Beverly, MA

Energy Technology Data Exchange (ETDEWEB)

1982-04-01

Performance data are given for a grid-connected photovoltaic power supply at a Massachusetts high school for the month of March, 1982. Data presented include: daily and monthly electrical energy produced; daily and monthly solar energy incident in the array plane; daily and monthly array efficiency; energy produced as a function of power level, voltage, cell temperature, and hour of the day; power conditioner input, output, and efficiency for two power conditioner units and for the overall power conditioning system; daily and monthly photovoltaic energy to load and the corresponding dollar value; grid to load energy from February 17 through April 5; photovoltaic system efficiency; capacity factor; daily system availability; daily and hourly insolation; heating and cooling degree days; hourly and monthly ambient temperature; hourly and monthly wind speed; wind direction distribution; number of freeze/thaw cycles; hourly cell temperature; and data acquisition mode and recording interval plot. Also included are seven summaries of site events. (LEW)

Development of interim test methods and procedures for determining the performance of small photovoltaic systems

Energy Technology Data Exchange (ETDEWEB)

McNutt, P.; Kroposki, B.; Hansen, R.; Algra, K.; DeBlasio, R. [National Renewable Energy Lab., Golden, CO (United States)

1998-09-01

The National Renewable Energy Laboratory (NREL) is developing tests and procedures that will determine if the configuration of a small photovoltaic (PV) system is suitable for its intended use, and if the system will perform as specified. An overview of these procedures is presented in this paper. Development of standard test procedures will allow designers, manufacturers, system integrators, users, and independent laboratories to assess the performance of PV systems under outdoor prevailing conditions. An NREL Technical Report detailing the procedures is under way, and the IEEE Standards Coordinating Committee 21 (SCC21) has established a project on this subject. The work will be submitted to the IEEE SCC21 and International Electrotechnical Commission Technical Committee 82 (IEC TC82) for consideration as a consensus standard. Certification bodies such as PowerMark and PV Global Approval Program (PVGAP) may adopt the IEC and IEEE documents when testing systems. Developing standardized test methods and procedures at NREL to evaluate the outdoor performance of PV systems will encourage product quality and promote PV standards development. Standardized tests will assure people that PV systems will perform as specified for their intended applications. As confidence in PV systems increases, the successful commercialization of PV will grow internationally.

Evaluation of photovoltaic panel temperature in realistic scenarios

International Nuclear Information System (INIS)

Du, Yanping; Fell, Christopher J.; Duck, Benjamin; Chen, Dong; Liffman, Kurt; Zhang, Yinan; Gu, Min; Zhu, Yonggang

2016-01-01

Highlights: • The developed realistic model captures more reasonably the thermal response and hysteresis effects. • The predicted panel temperature is as high as 60 °C under a solar irradiance of 1000 W/m"2 in no-wind weather. • In realistic scenarios, the thermal response normally takes 50–250 s. • The actual heating effect may cause a photoelectric efficiency drop of 2.9–9.0%. - Abstract: Photovoltaic (PV) panel temperature was evaluated by developing theoretical models that are feasible to be used in realistic scenarios. Effects of solar irradiance, wind speed and ambient temperature on the PV panel temperature were studied. The parametric study shows significant influence of solar irradiance and wind speed on the PV panel temperature. With an increase of ambient temperature, the temperature rise of solar cells is reduced. The characteristics of panel temperature in realistic scenarios were analyzed. In steady weather conditions, the thermal response time of a solar cell with a Si thickness of 100–500 μm is around 50–250 s. While in realistic scenarios, the panel temperature variation in a day is different from that in steady weather conditions due to the effect of thermal hysteresis. The heating effect on the photovoltaic efficiency was assessed based on real-time temperature measurement of solar cells in realistic weather conditions. For solar cells with a temperature coefficient in the range of −0.21%∼−0.50%, the current field tests indicated an approximate efficiency loss between 2.9% and 9.0%.

Materials for Photovoltaic Applications

Science.gov (United States)

Dimova-Malinovska, Doriana

Energy priorities are changing nowadays. As mankind will probably have to face energy crisis, factors such as energy independence, energy security, stability of energy supply and the variety of energy sources become much more vital these days. Photovoltaics is exceptional compared to other renewable sources of energy due to its wide opportunity to gain energetic and environmental benefits. An overview of the present state of knowledge of the materials aspects of photovoltaic cells will be given, and new semiconductor materials, including nanomaterials, with potential for application in photovoltaic devices will be identified.

Experimental Comparison of Two Configurations of Hybrid Photovoltaic Thermal Collectors

International Nuclear Information System (INIS)

Khaled Toufeka; Mourad Haddadib; Ali Mkc

2011-01-01

The combination of a thermal collector and a photovoltaic module in a single system allows for increased efficiency of the total conversion of solar energy. A synergistic effect can be obtained in a structure combining these two devices in a judicious manner to those of thermal and photovoltaic system installed separately. Production of total energy from hybrid collector depends on the input (that is to say, the. energy of solar radiation, air temperature and wind speed) and output which is the electric production and the temperature of the system. Thin production also depends on the mode of heal extraction. In this paper, an experimental Study of two configurations of hybrid collectors is described. The configuration that the absorber is made by galvanized steel and in the second, the absorber is a copper serpentine. The advantages of the first configuration are mainly due to low cost and simplicity but the second configuration has the advantage of promoting the heat transfer between cells and fluid. (authors)

Advanced tendencies in development of photovoltaic cells for power engineering

Science.gov (United States)

Strebkov, D. S.

2015-01-01

Development of solar power engineering must be based on original innovative Russian and world technologies. It is necessary to develop promising Russian technologies of manufacturing of photovoltaic cells and semiconductor materials: chlorine-free technology for obtaining solar silicon; matrix solar cell technology with an efficiency of 25-30% upon the conversion of concentrated solar, thermal, and laser radiation; encapsulation technology for high-voltage silicon solar modules with a voltage up to 1000 V and a service life up to 50 years; new methods of concentration of solar radiation with the balancing illumination of photovoltaic cells at 50-100-fold concentration; and solar power systems with round-the-clock production of electrical energy that do not require energy storage devices and reserve sources of energy. The advanced tendency in silicon power engineering is the use of high-temperature reactions in heterogeneous modular silicate solutions for long-term (over one year) production of heat and electricity in the autonomous mode.

Implications of small water leak reactions on sodium heated steam generator design

Energy Technology Data Exchange (ETDEWEB)

Smedley, J A

1975-07-01

Various types of sodium water reactions have been looked on as possibly causing hazard conditions in sodium heated steam generator units ranging from the very improbable boiler tube double ended guillotine fracture to the almost certain occurrence of micro-leaks. Within this range small water leaks reactions have attracted particular interest and the present paper looks at the principles of associating the reactions with detection and protection systems for Commercial Fast Reactors. A method is developed for assessing whether adequate protection has been provided against the effects of small water leak reactions in a steam generator unit. (author)

Efficiencies and improvement potential of building integrated photovoltaic thermal (BIPVT) system

International Nuclear Information System (INIS)

Ibrahim, Adnan; Fudholi, Ahmad; Sopian, Kamaruzzaman; Othman, Mohd Yusof; Ruslan, Mohd Hafidz

2014-01-01

Highlights: • Performances analysis of BIPVT solar collector based on energy and exergy analyses. • A new absorber design of BIPVT solar collector is presented. • BIPVT solar collector is produced primary-energy saving efficiency from about 73% to 81%. • PVT energy efficiency varies between 55% and 62% where as the variation in the PVT exergy efficiency is from 12% to 14%. • The improvement potential is between 98 and 404 W. - Abstract: Building integrated photovoltaic thermal (BIPVT) system has been designed to produce both electricity and hot water and later integrated to building. The hot water is produced at the useful temperatures for the applications in Malaysia such as building integrated heating system and domestic hot water system as well as many industrial including agricultural and commercial applications. The photovoltaic thermal (PVT) system comprises of a high efficiency multicrystal photovoltaic (PV) module and spiral flow absorber for BIPVT application, have been performed and investigated. In this study, it was assumed that the absorber was attached underneath the flat plate single glazing sheet of polycrystalline silicon PV module and water has been used as a heat transfer medium in absorber. Performances analysis of BIPVT system based on energy and exergy analyses. It was based on efficiencies including energy and exergy, and exergetic improvement potential (IP) based on the metrological condition of Malaysia has been carried out. Results show that the hourly variation for BIPVT system, the PVT energy efficiency of 55–62% is higher than the PVT exergy efficiency of 12–14%. The improvement potential increases with increasing solar radiation, it is between 98 and 404 W. On the other hand, BIPVT system was produced primary-energy saving efficiency from about 73% to 81%

Parametric study of laser photovoltaic energy converters

Science.gov (United States)

Walker, G. H.; Heinbockel, J. H.

1987-01-01

Photovoltaic converters are of interest for converting laser power to electrical power in a space-based laser power system. This paper describes a model for photovoltaic laser converters and the application of this model to a neodymium laser silicon photovoltaic converter system. A parametric study which defines the sensitivity of the photovoltaic parameters is described. An optimized silicon photovoltaic converter has an efficiency greater than 50 percent for 1000 W/sq cm of neodymium laser radiation.

Photovoltaic research and development

CSIR Research Space (South Africa)

Cummings, F

2009-09-01

Full Text Available Photovoltaic (PV) is the direct conversion of sunlight into electrical energy through a solar cell. This presentation consists of an introduction to photovoltaics, the South African PV research roadmap, a look at the CSIR PV research and development...

Case Study - Monitoring the Photovoltaic Panels

OpenAIRE

PACURAR Ana Talida; TOADER Dumitru; PACURAR Cristian

2014-01-01

The photovoltaic cell represents one of the most dynamic and attractive way to converts renewable energy sources in electricity production. That means to convert solar energy into electricity. In this paper is presented a analogy between two types of photovoltaic panels installed, with educational role for students. Also the objective of this paper is to estimate the performance of photovoltaic panels and to provide the best solution for industry. These two types of photovoltaic panels wer...

Enhancing ultra-high CPV passive cooling using least-material finned heat sinks

Energy Technology Data Exchange (ETDEWEB)

Micheli, Leonardo, E-mail: lm409@exeter.ac.uk; Mallick, Tapas K., E-mail: T.K.Mallick@exeter.ac.uk [Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE (United Kingdom); Fernandez, Eduardo F., E-mail: E.Fernandez-Fernandez2@exeter.ac.uk [Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE (United Kingdom); Centre of Advanced Studies in Energy and Environment, University of Jaen, Jaen 23071 (Spain); Almonacid, Florencia, E-mail: facruz@ujaen.es [Centre of Advanced Studies in Energy and Environment, University of Jaen, Jaen 23071 (Spain); Reddy, K. S., E-mail: ksreddy@iitm.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, 600036 (India)

2015-09-28

Ultra-high concentrating photovoltaic (CPV) systems aim to increase the cost-competiveness of CPV by increasing the concentrations over 2000 suns. In this work, the design of a heat sink for ultra-high concentrating photovoltaic (CPV) applications is presented. For the first time, the least-material approach, widely used in electronics to maximize the thermal dissipation while minimizing the weight of the heat sink, has been applied in CPV. This method has the potential to further decrease the cost of this technology and to keep the multijunction cell within the operative temperature range. The designing procedure is described in the paper and the results of a thermal simulation are shown to prove the reliability of the solution. A prediction of the costs is also reported: a cost of 0.151$/W{sub p} is expected for a passive least-material heat sink developed for 4000x applications.

Polymer substrates for flexible photovoltaic cells application in personal electronic system

Science.gov (United States)

Znajdek, K.; Sibiński, M.; Strąkowska, A.; Lisik, Z.

2016-01-01

The article presents an overview of polymeric materials for flexible substrates in photovoltaic (PV) structures that could be used as power supply in the personal electronic systems. Four types of polymers have been elected for testing. The first two are the most specialized and heat resistant polyimide films. The third material is transparent polyethylene terephthalate film from the group of polyesters which was proposed as a cheap and commercially available substrate for the technology of photovoltaic cells in a superstrate configuration. The last selected polymeric material is a polysiloxane, which meets the criteria of high elasticity, is temperature resistant and it is also characterized by relatively high transparency in the visible light range. For the most promising of these materials additional studies were performed in order to select those of them which represent the best optical, mechanical and temperature parameters according to their usage for flexible substrates in solar cells.

Optimal Sizing Of An Off-Grid Small Hydro-Photovoltaic-Diesel Generator Hybrid Power System For A Distant Village

Directory of Open Access Journals (Sweden)

Adebanji B.

2017-08-01

Full Text Available This paper presented an optimal sizing technique for an off-grid hybrid system consisting of Small Hydro SHP system Photovoltaic PV modules Battery BATT banks and Diesel Generator DG. The objective cost function Annualized Cost System and the Loss of Power Supply Probability LPSP were minimized with application of Genetic Algorithm GA in order to reduce the Cost of Energy COE generation. GA compared to other convectional optimization methods has the ability to attain global optimum easily. The decision variables are the number of small hydro turbines NSHP number of solar panels NPV number of battery banks NBATT and the capacity of DG PDG. The proposed method was applied to a typical rural village Itapaji-Ekiti in Nigeria. The monthly average solar irradiance data were converted into hourly solar irradiance data for uniformity. Sensitivity analysis was also performed to identify the most important parameter influencing the optimized hybrid system. The optimal sizing result of the HPS is 954 kW of SHP 290 kW of PV panels 9500 sets of 600Ah battery strings and 350 kW of DG. The optimal Loss of Power Supply Probability LPSP is 0.0054 and the Renewable Fraction RF is 0.62 which is indeed a significant improvement on the environment and comparatively better than any other combinations in the system.

Study of the heat transfers spectral radiation - conduction - natural convection in hybrid photovoltaic systems for buildings

International Nuclear Information System (INIS)

Muresan, C.

2005-01-01

The present work is supported by the CSTB and the ADEME and is a part of an Integrated Research Project - Energy Program of CNRS - (http://www.imp.cnrs.fr/energie/) coordinated by the CETHIL: 'Integration of hybrid Thermal - Photovoltaic solar collector in buildings'. In this context, this thesis represents upstream studies led in the I.R.P., pursuing the study itself of these hybrid components in stage of integration to the framework of buildings (thermal/electric management in response to the needs). Its objective falls under an action to identify and look further into knowledge of the limiting factors of the efficiency of these hybrid components (the operating temperature of the photosensitive cells), to identify the enduring scientific bolts persisting and to contribute to removing them. To reach this aim, predictive numerical tools are developed in order to guide and follow the future evolutions of these active wall elements. The problems related to the Photovoltaic components of Mono or Poly crystalline type, namely the risk of heating of the modules included within the built framework that can lead to a degradation of their energy efficiency. The developed model aims at obtaining the evaluation of the internal field of temperature. The modeling of the radiative behavior of multi-layer components of not scattering semi-transparent media is carried out. Propagation of a collimated flux corresponds to the direct solar radiation, and a diffuse flux represents the solar radiation diffused and that resulting from the other external sources (environment). Both are treated in a separate way. The incidental radiation power and radiative net flux are thus evaluated by a superposition of the values obtained at the time of the separate studies of the two components. The collimated component of incidental flux is treated according to an approach of 'ray tracing' type. The Discrete Ordinates Method (DOM) associated to the method of finite volumes, is employed for the

Is organic photovoltaics promising for indoor applications?

Science.gov (United States)

Lee, Harrison K. H.; Li, Zhe; Durrant, James R.; Tsoi, Wing C.

2016-06-01

This work utilizes organic photovoltaics (OPV) for indoor applications, such as powering small electronic devices or wireless connected Internet of Things. Three representative polymer-based OPV systems, namely, poly(3-hexylthiophene-2,5-diyl), poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)], and poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

Grounds of two positions photovoltaic panels

OpenAIRE

Castán Fortuño, Fernando

2008-01-01

The objective of this Master Thesis is to find the optimum positioning for a two positions photovoltaic panel. Hence, it will be implemented a model in order to optimize the energy of the sun that the photovoltaic panel is receiving by its positioning. Likewise this project will include the comparison with other photovoltaic panel systems as the single position photovoltaics panels. Ultimately, it is also going to be designed a system array for the optimized model of two positions photovoltai...

Automated synthesis of photovoltaic-quality colloidal quantum dots using separate nucleation and growth stages

KAUST Repository

Pan, Jun; El-Ballouli, AlA'A O.; Rollny, Lisa R.; Voznyy, Oleksandr; Burlakov, Victor M.; Goriely, Alain; Sargent, E. H.; Bakr, Osman

2013-01-01

As colloidal quantum dot (CQD) optoelectronic devices continue to improve, interest grows in the scaled-up and automated synthesis of high-quality materials. Unfortunately, all reports of record-performance CQD photovoltaics have been based on small

Applied photovoltaics

CERN Document Server

Wenham, Stuart R; Watt, Muriel E; Corkish, Richard; Sproul, Alistair

2013-01-01

The new edition of this thoroughly considered textbook provides a reliable, accessible and comprehensive guide for students of photovoltaic applications and renewable energy engineering. Written by a group of award-winning authors it is brimming with information and is carefully designed to meet the needs of its readers. Along with exercises and references at the end of each chapter, it features a set of detailed technical appendices that provide essential equations, data sources and standards. The new edition has been fully updated with the latest information on photovoltaic cells,

Special issue photovoltaic

International Nuclear Information System (INIS)

2004-01-01

In this letter of the INES (french National Institute of the Solar Energy), a special interest is given to photovoltaic realizations in Europe. Many information are provided on different topics: the China future fifth world producer of cells in 2005, batteries and hydrogen to storage the solar energy and a technical sheet on a photovoltaic autonomous site installation for electric power production. (A.L.B.)

Photovoltaic solar energy. Proceedings; Photovoltaische Solarenergie. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

and limits (Mike Meinhardt); (17) Washing with the sun - Direct consumption of locally generated PV current by means of directed load shift in private households (Georg Bopp); (18) Efficiency by synergy. Export initiative renewable energies (Berthold Breid); (19) Modular PV power supply in the Empire of the Midth (Michael Wollny); (20) Breakthrough to a new era of PV hybrid systems with the help of standardised components communication? (Michael Mueller); (21) New PV stand-alone supply for frequency variable loads (Wolfgang Hernschier); (22) Characterization of solar batteries in long-term investigations according IEC 61427 (Wolfgang Wiesner); (23) Professional PV plant configuration - the status quo of the PV prpgrams (Mike Zehner); (24) Simulating renewable power projects with greenius{sup Free} (Volker Quaschning); (25) Analysis of the effect of shade and equivalent circuit of PV modules with the simulation software ''Solar Pro'' (Yusuke Mataki); (26) From data sheet values to the system gain - on realistic modelling of small PV generators (Hans Georg Beyer); (27) Form follows function - follows form function? - Ineractions between building functions and photovoltaic (Wolfgang Willkomm); (28) Market chances and technology perspectives for the Swiss facade construction by means of building integrated PV systems (Reto Miloni); (29) Passiv solar office building BIOHAUS Paderborn - architectonic overview and a first energy balance (Willi Ernst, Ralf Zirkler); (30) Building integration and education in Austria (Gernot Becker); (31) Photovoltaic and light (Thomas Herzog); (32) 10 years of test experience with the certification of design of photovoltaic modules (Andreas Cox); (32) Large size solar cells and the IEC 61215 - New challenges for the module junction (Eckehard Hofmueller); (33) Limits of power output optimisation of PV arrays by pre-sorting of PV modules (Werner Herrmann); (34) Coloured and patterned CIS modules (Dieter Geyer); (35) Energy

Pyroelectric photovoltaic spatial solitons in unbiased photorefractive crystals

International Nuclear Information System (INIS)

Jiang, Qichang; Su, Yanli; Ji, Xuanmang

2012-01-01

A new type of spatial solitons i.e. pyroelectric photovoltaic spatial solitons based on the combination of pyroelectric and photovoltaic effect is predicted theoretically. It shows that bright, dark and grey spatial solitons can exist in unbiased photovoltaic photorefractive crystals with appreciable pyroelectric effect. Especially, the bright soliton can form in self-defocusing photovoltaic crystals if it gives larger self-focusing pyroelectric effect. -- Highlights: ► A new type of spatial soliton i.e. pyroelectric photovoltaic spatial soliton is predicted. ► The bright, dark and grey pyroelectric photovoltaic spatial soliton can form. ► The bright soliton can also exist in self-defocusing photovoltaic crystals.

Socioeconomic impact of photovoltaic power at Schuchulik, Arizona. Final report

Energy Technology Data Exchange (ETDEWEB)

Bahr, D.; Garrett, B.G.; Chrisman, C.

1980-10-01

Schuchuli, a small remote village on the Papago Indian Reservation in southwest Arizona, is 27 kilometers (17 miles) from the nearest available utility power. In some respects, Schuchuli resembles many of the rural villages in other parts of the world. For example, it's relatively small in size (about 60 residents), composed of a number of extended family groupings, and remotely situated relative to major population centers (190 km, or 120 miles, from Tucson). Its lack of conventional power is due to the prohibitive cost of supplying a small electrical load with a long-distance distribution line. Furthermore, alternate energy sources are expensive and place a burden on the resources of the villagers. On December 16, 1978, as part of a federally funded project, a solar cell power system was put into operation at Schuchuli. The system powers the village water pump, lighting for homes ad other village buildings, family refrigerators and a communal washing machine and sewing machine. The project, managed for the US Department of Energy by the NASA Lewis Research Center, provided for a one-year socio-economic study to assess the impact of a relatively small amount of electricity on the basic living environment of the villagers. The results of that study are presented, including village history, group life, energy use in general and the use of the photovoltaic-powered appliances. No significant impacts due to the photovoltaic power system were observed.

International photovoltaic program. Volume 2: Appendices

Science.gov (United States)

Costello, D.; Koontz, R.; Posner, D.; Heiferling, P.; Carpenter, P.; Forman, S.; Perelman, L.

1979-01-01

The results of analyses conducted in preparation of an international photovoltaic marketing plan are summarized. Included are compilations of relevant statutes and existing Federal programs; strategies designed to expand the use of photovoltaics abroad; information on the domestic photovoltaic plan and its impact on the proposed international plan; perspectives on foreign competition; industry views on the international photovoltaic market and ideas about the how US government actions could affect this market;international financing issues; and information on issues affecting foreign policy and developing countries.

Solar photovoltaic reflective trough collection structure

Science.gov (United States)

Anderson, Benjamin J.; Sweatt, William C.; Okandan, Murat; Nielson, Gregory N.

2015-11-19

A photovoltaic (PV) solar concentration structure having at least two troughs encapsulated in a rectangular parallelepiped optical plastic structure, with the troughs filled with an optical plastic material, the troughs each having a reflective internal surface and approximately parabolic geometry, and the troughs each including photovoltaic cells situated so that light impinging on the optical plastic material will be concentrated onto the photovoltaic cells. Multiple structures can be connected to provide a solar photovoltaic collection system that provides portable, efficient, low-cost electrical power.

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

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

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

Characterization of Photovoltaic Generators

Science.gov (United States)

Boitier, V.; Cressault, Y.

2011-01-01

This paper discusses photovoltaic panel systems and reviews their electrical properties and use in several industrial fields. We explain how different photovoltaic panels may be characterized by undergraduate students at university using simple methods to retrieve their electrical properties (power, current and voltage) and compare these values…

Atom-probe tomographic study of interfaces of Cu{sub 2}ZnSnS{sub 4} photovoltaic cells

Energy Technology Data Exchange (ETDEWEB)

Tajima, S., E-mail: e0954@mosk.tytlabs.co.jp; Asahi, R.; Itoh, T.; Hasegawa, M.; Ohishi, K. [Toyota Central R and D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan); Isheim, D.; Seidman, D. N. [Northwestern University, Evanston, Illinois 60208-3108 (United States)

2014-09-01

The heterophase interfaces between the CdS buffer layer and the Cu{sub 2}ZnSnS{sub 4} (CZTS) absorption layers are one of the main factors affecting photovoltaic performance of CZTS cells. We have studied the compositional distributions at heterophase interfaces in CZTS cells using three-dimensional atom-probe tomography. The results demonstrate: (a) diffusion of Cd into the CZTS layer; (b) segregation of Zn at the CdS/CZTS interface; and (c) a change of oxygen and hydrogen concentrations in the CdS layer depending on the heat treatment. Annealing at 573 K after deposition of CdS improves the photovoltaic properties of CZTS cells probably because of the formation of a heterophase epitaxial junction at the CdS/CZTS interface. Conversely, segregation of Zn at the CdS/CZTS interface after annealing at a higher temperature deteriorates the photovoltaic properties.

The players of the photovoltaic sector in France

International Nuclear Information System (INIS)

Houot, G.

2012-01-01

This document reviews 338 players in the French photovoltaic industry. Each player can be the owner of a photovoltaic power plant, or its operator, or the manufacturer of photovoltaic systems, or the manufacturer of components involved in photovoltaic systems, or the equipment wholesaler, or the designer of photovoltaic projects, or the photovoltaic system installer. For each player some pieces of information are gathered: a brief history of the enterprise, the enterprise activity, its staff, its turnover, its main achievements and its prospects. (A.C.)

Application of sorption heat pumps for increasing of new power sources efficiency

Science.gov (United States)

Vasiliev, L.; Filatova, O.; Tsitovich, A.

2010-07-01

In the 21st century the way to increase the efficiency of new sources of energy is directly related with extended exploration of renewable energy. This modern tendency ensures the fuel economy needs to be realized with nature protection. The increasing of new power sources efficiency (cogeneration, trigeneration systems, fuel cells, photovoltaic systems) can be performed by application of solid sorption heat pumps, regrigerators, heat and cold accumulators, heat transformers, natural gas and hydrogen storage systems and efficient heat exchangers.

Nanostructured Photovoltaics for Space Power

Data.gov (United States)

National Aeronautics and Space Administration — The NASA NSTRF proposal entitled Nanostructured Photovoltaics for Space Power is targeted towards research to improve the current state of the art photovoltaic...

Print-Assisted Photovoltaic Assembly (PAPA)

Data.gov (United States)

National Aeronautics and Space Administration — This proposal describes the development of an innovative method for the fabrication of thin-film photovoltaic panels. Print-Assisted Photovoltaic Assembly, or PAPA,...

Emissions from photovoltaic life cycles.

Science.gov (United States)

Fthenakis, Vasilis M; Kim, Hyung Chul; Alsema, Erik

2008-03-15

Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004-2006, this study presents the life-cycle greenhouse gas emissions, criteria pollutant emissions, and heavy metal emissions from four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride. Life-cycle emissions were determined by employing average electricity mixtures in Europe and the United States during the materials and module production for each PV system. Among the current vintage of PV technologies, thin-film cadmium telluride (CdTe) PV emits the least amount of harmful air emissions as it requires the least amount of energy during the module production. However, the differences in the emissions between different PV technologies are very small in comparison to the emissions from conventional energy technologies that PV could displace. As a part of prospective analysis, the effect of PV breeder was investigated. Overall, all PV technologies generate far less life-cycle air emissions per GWh than conventional fossil-fuel-based electricity generation technologies. At least 89% of air emissions associated with electricity generation could be prevented if electricity from photovoltaics displaces electricity from the grid.

Plastic photovoltaic devices

OpenAIRE

Niyazi Serdar Sariciftci

2004-01-01

The development of organic, polymer-based photovoltaic elements has introduced the possibility of obtaining cheap and easy-to-produce energy from light. Photoinduced electron transfer from donor-type semiconducting polymers onto acceptor-type polymers or molecules, such as C60, is the basic phenomenon utilized in these photovoltaic devices. This process mimics the early photo-effects in natural photosynthesis. The polymeric semiconductors combine the photoelectrical properties of inorganic se...

Dynamic Control Based Photovoltaic Illuminating System

Directory of Open Access Journals (Sweden)

Zhang Chengkai

2016-01-01

Full Text Available Smart LED illumination system can use the power from whether the photovoltaic cell or the power grid automatically based on the SOC (State Of Charge of the photovoltaic cell. This paper proposes a feedback control of the photovoltaic cells and a dynamic control strategy for the Energy system. The dynamic control strategy is used to determine the switching state of the photovoltaic cell based on the illumination load in the past one hour and the battery capacity. These controls are manifested by experimental prototype that the control scheme is correct and effective.

Photovoltaics and renewable energies in Europe

International Nuclear Information System (INIS)

Jaeger-Waldau, Arnulf

2007-01-01

Photovoltaics and renewable energies are growing at a much faster pace than the rest of the economy in Europe and worldwide. This and the dramatic oil price increases in 2005 have led to a remarkable re-evaluation of the renewable energy sector by politics and financing institutions. Despite the fact that there are still discrepancies between the European Union and the USA, as to how to deal with climate change, renewable energies will play an important role for the implementation of the Kyoto Protocol and the worldwide introduction of tradable Green Certificates. Apart from the electricity sector, renewable energy sources for the generation of heat and the use of environment friendly biofuels for the transport sector will become more and more important in the future. (author)

Photovoltaic venture analysis. Final report. Volume III. Appendices

Energy Technology Data Exchange (ETDEWEB)

Costello, D.; Posner, D.; Schiffel, D.; Doane, J.; Bishop, C.

1978-07-01

This appendix contains a brief summary of a detailed description of alternative future energy scenarios which provide an overall backdrop for the photovoltaic venture analysis. Also included is a summary of a photovoltaic market/demand workshop, a summary of a photovoltaic supply workshop which used cross-impact analysis, and a report on photovoltaic array and system prices in 1982 and 1986. The results of a sectorial demand analysis for photovoltaic power systems used in the residential sector (single family homes), the service, commercial, and institutional sector (schools), and in the central power sector are presented. An analysis of photovoltaics in the electric utility market is given, and a report on the industrialization of photovoltaic systems is included. A DOE information memorandum regarding ''A Strategy for a Multi-Year Procurement Initiative on Photovoltaics (ACTS No. ET-002)'' is also included. (WHK)

Retrofitting of photovoltaic power plants, government liability law and fundamental right of property; Solarenergieanlagen-Nachruestung, Staatshaftungsrecht und Eigentumsgrundrecht

Energy Technology Data Exchange (ETDEWEB)

Ekardt, Felix [Forschungsstelle Nachhaltigkeit und Klimapolitik (Germany); Rostock Univ. (Germany). Oeffentliches Recht und Rechtsphilosophie

2012-02-15

The German legislator plans the re-regulation of the plant safety for existing photovoltaic systems in order to avoid a massive shutdown of these plants, followed by network instability. The current re-regulation particularly is problematic for operators of small photovoltaic systems and is a summary of the property and no expropriation. The German legislature is obliged, not to charge the costs of the planned reorganization of the plant safety to the operators of photovoltaic systems. The Federal State has to be responsible for the former error of the VDE standards organizations. The VDE standards organizations did not recognize the problem of network instability to be regulated.

Technoeconomic Evaluation for an Installed Small-Scale Photovoltaic Power Plant

Directory of Open Access Journals (Sweden)

Bulent Yaniktepe

2017-01-01

Full Text Available Solar energy production and economic evaluation are analyzed, in this study, by using daily solar radiation and average temperature data which are measured for 3 years in the Osmaniye province in Turkey. Besides, this study utilizes the photovoltaic- (PV- based grid connected to a power plant which has an installed capacity of 1 MW investment in electricity production. Economic values show that the net present value (NPV, the first economic method in the research, is about 111941 USD, which is greater than zero. Therefore, the payback year of this investment is approximately 8.3. The second one of these methods, the payback period of the simple payback period (PBP, is 6.27 years. The last method, which is the mean value of the internal rate of return (IRR, is 10.36%. The results of this study show that Osmaniye is a considerable region for the PV investment in electricity production. As a result, investment of a PV system in Osmaniye can be applicable.

Solar Thermoelectricity via Advanced Latent Heat Storage: A Cost-Effective Small-Scale CSP Application

Energy Technology Data Exchange (ETDEWEB)

Glatzmaier, Greg C.; Rea, J.; Olsen, Michele L.; Oshman, C.; Hardin, C.; Alleman, Jeff; Sharp, J.; Weigand, R.; Campo, D.; Hoeschele, G.; Parilla, Philip A.; Siegel, N. P.; Toberer, Eric S.; Ginley, David S.

2017-06-27

We are developing a novel concentrating solar electricity-generating technology that is both modular and dispatchable. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) uses concentrated solar flux to generate high-temperature thermal energy, which directly converts to electricity via thermoelectric generators (TEGs), stored within a phase-change material (PCM) for electricity generation at a later time, or both allowing for simultaneous charging of the PCM and electricity generation. STEALS has inherent features that drive its cost-competitive scale to be much smaller than current commercial concentrating solar power (CSP) plants. Most obvious is modularity of the solid-state TEG, which favors smaller scales in the kilowatt range as compared to CSP steam turbines, which are minimally 50 MWe for commercial power plants. Here, we present techno-economic and market analyses that show STEALS can be a cost-effective electricity-generating technology with particular appeal to small-scale microgrid applications. We evaluated levelized cost of energy (LCOE) for STEALS and for a comparable photovoltaic (PV) system with battery storage. For STEALS, we estimated capital costs and the LCOE as functions of the type of PCM including the use of recycled aluminum alloys, and evaluated the cost tradeoffs between plasma spray coatings and solution-based boron coatings that are applied to the wetted surfaces of the PCM subsystem. We developed a probabilistic cost model that accounts for uncertainties in the cost and performance inputs to the LCOE estimation. Our probabilistic model estimated LCOE for a 100-kWe STEALS system that had 5 hours of thermal storage and 8-10 hours of total daily power generation. For these cases, the solar multiple for the heliostat field varied between 1.12 and 1.5. We identified microgrids as a likely market for the STEALS system. We characterized microgrid markets in terms of nominal power, dispatchability, geographic location, and

Solar thermoelectricity via advanced latent heat storage: A cost-effective small-scale CSP application

Science.gov (United States)

Glatzmaier, G. C.; Rea, J.; Olsen, M. L.; Oshman, C.; Hardin, C.; Alleman, J.; Sharp, J.; Weigand, R.; Campo, D.; Hoeschele, G.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

2017-06-01

We are developing a novel concentrating solar electricity-generating technology that is both modular and dispatchable. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) uses concentrated solar flux to generate high-temperature thermal energy, which directly converts to electricity via thermoelectric generators (TEGs), stored within a phase-change material (PCM) for electricity generation at a later time, or both allowing for simultaneous charging of the PCM and electricity generation. STEALS has inherent features that drive its cost-competitive scale to be much smaller than current commercial concentrating solar power (CSP) plants. Most obvious is modularity of the solid-state TEG, which favors smaller scales in the kilowatt range as compared to CSP steam turbines, which are minimally 50 MWe for commercial power plants. Here, we present techno-economic and market analyses that show STEALS can be a cost-effective electricity-generating technology with particular appeal to small-scale microgrid applications. We evaluated levelized cost of energy (LCOE) for STEALS and for a comparable photovoltaic (PV) system with battery storage. For STEALS, we estimated capital costs and the LCOE as functions of the type of PCM including the use of recycled aluminum alloys, and evaluated the cost tradeoffs between plasma spray coatings and solution-based boron coatings that are applied to the wetted surfaces of the PCM subsystem. We developed a probabilistic cost model that accounts for uncertainties in the cost and performance inputs to the LCOE estimation. Our probabilistic model estimated LCOE for a 100-kWe STEALS system that had 5 hours of thermal storage and 8-10 hours of total daily power generation. For these cases, the solar multiple for the heliostat field varied between 1.12 and 1.5. We identified microgrids as a likely market for the STEALS system. We characterized microgrid markets in terms of nominal power, dispatchability, geographic location, and

Understanding the physical properties of hybrid perovskites for photovoltaic applications

Science.gov (United States)

Huang, Jinsong; Yuan, Yongbo; Shao, Yuchuan; Yan, Yanfa

2017-07-01

New photovoltaic materials have been searched for in the past decades for clean and renewable solar energy conversion with an objective of reducing the levelized cost of electricity (that is, the unit price of electricity over the course of the device lifetime). An emerging family of semiconductor materials — organic-inorganic halide perovskites (OIHPs) — are the focus of the photovoltaic research community owing to their use of low cost, nature-abundant raw materials, low-temperature and scalable solution fabrication processes, and, in particular, the very high power conversion efficiencies that have been achieved within the short time of their development. In this Review, we summarize and critically assess the most recent advances in understanding the physical properties of both 3D and low-dimensional OIHPs that favour a small open-circuit voltage deficit and high power conversion efficiency. Several prominent topics in this field on the unique properties of OIHPs are surveyed, including defect physics, ferroelectricity, exciton dissociation processes, carrier recombination lifetime and photon recycling. The impact of ion migration on solar cell efficiency and stability are also critically analysed. Finally, we discuss the remaining challenges in the commercialization of OIHP photovoltaics.

Molecular and polymeric organic semiconductors for applications in photovoltaic devices

International Nuclear Information System (INIS)

Meinhardt, G.

2000-01-01

Photovoltaic devices based on molecular as well as polymeric semiconductors were investigated and characterized. The organic materials presented here exhibit the advantages of low price, low processing costs and the possibility of tuning their optical properties. The photovoltaic properties were investigated by photocurrent action spectroscopy and I/V-characterization and the electric field distribution in each layer by electroabsorption spectroscopy. Single layer devices of molecular semiconductors and semiconducting polymers like methyl-substituted polyparaphenylene, CN-Ether-PPV, copper-phthalocyanine, the terryleneimide DOTer, the perylene derivatives BBP-perylene and polyBBP-perylene show low photocurrents as well as a small photovoltaic effect in their pristine form. One way to enhance the performance is to blend the active layer with molecular dopands like a soluble form of titaniumoxophthalocyanine or the aromatic macromolecule RS19 or to combine two organic semiconductors in heterostructure devices. The motivation for these experiments was the optimization of either charge transfer or energy transfer from one molecule to its neighbor molecule. A model based on the internal filter effect was used for fitting the photoresponse of single layer devices. For optimising heterostructure solar cells a more sophisticated theoretical model taking into account interference effects was used. (author)

Power generation using photovoltaic induction in an isolated power network

International Nuclear Information System (INIS)

Kalantar, M.; Jiang, J.

2001-01-01

Owing to increased emphasis on renewable resources, the development of suitable isolated power generators driven by energy sources, the development of suitable isolated power generators driven by energy sources such as photovoltaic, wind, small hydroelectric, biogas and etc. has recently assumed greater significance. A single phase capacitor self excited induction generator has emerged as a suitable candidate of isolated power sources. This paper presents performance analysis of a single phase self-excited induction generator driven by photovoltaic (P V) system for low power isolated stand-alone applications. A single phase induction machine can work as a self-excited induction generator when its rotor is driven at suitable speed by an photovoltaic powered do motor. Its excitation is provided by connecting a single phase capacitor bank at a stator terminals. Either to augment grid power or to get uninterrupted power during grid failure stand-alone low capacity ac generators are used. These are driven by photovoltaic, wind power or I C engines using kerosene, diesel, petrol or biogas as fuel. Self-excitation with capacitors at the stator terminals of the stator terminals of the induction machines is well demonstrated experimentally on a P V powered dc motor-induction machine set. The parameters and the excitation requirements of the induction machine run in self-excited induction generator mode are determined. The effects of variations in prime mover speed,terminal capacitance and load power factor on the machine terminal voltage are studied

Photovoltaic technologies

International Nuclear Information System (INIS)

Bagnall, Darren M.; Boreland, Matt

2008-01-01

Photovoltaics is already a billion dollar industry. It is experiencing rapid growth as concerns over fuel supplies and carbon emissions mean that governments and individuals are increasingly prepared to ignore its current high costs. It will become truly mainstream when its costs are comparable to other energy sources. At the moment, it is around four times too expensive for competitive commercial production. Three generations of photovoltaics have been envisaged that will take solar power into the mainstream. Currently, photovoltaic production is 90% first-generation and is based on silicon wafers. These devices are reliable and durable, but half of the cost is the silicon wafer and efficiencies are limited to around 20%. A second generation of solar cells would use cheap semiconductor thin films deposited on low-cost substrates to produce devices of slightly lower efficiency. A number of thin-film device technologies account for around 5-6% of the current market. As second-generation technology reduces the cost of active material, the substrate will eventually be the cost limit and higher efficiency will be needed to maintain the cost-reduction trend. Third-generation devices will use new technologies to produce high-efficiency devices. Advances in nanotechnology, photonics, optical metamaterials, plasmonics and semiconducting polymer sciences offer the prospect of cost-competitive photovoltaics. It is reasonable to expect that cost reductions, a move to second-generation technologies and the implementation of new technologies and third-generation concepts can lead to fully cost-competitive solar energy in 10-15 years. (author)

Degradation analysis of the encapsulation polymer in photovoltaic modules by Raman spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Peike, Cornelia

2015-07-01

Understanding the degradation behavior of photovoltaic modules is of great importance for the production of reliable and durable PV modules. Within this work, the applicability of Raman spectroscopy as a non-destructive method for PV module degradation analysis was investigated. In addition, the influence of polymer stabilizers on the photochemical discoloration of EVA as well as the impact of EVA aging on the cell metallization degradation under damp-heat conditions was studied.

Characteristics of heat transfer and fluid flow in a channel with single-row plates array oblique to flow direction for photovoltaic/thermal system

International Nuclear Information System (INIS)

Ali, Ahmed Hamza H.; Ahmed, Mahmoud; Youssef, M.S.

2010-01-01

This study has been carried out to investigate the characteristics of convective heat transfer and fluid flow for a single row of oblique plates array to the flow direction inside a channel. The flow inside the channel is laminar and the plates array have spanwise distance between the plates and heated by radiation. This configuration has been designed to be used for Photovoltaic/Thermal system (PV/T) applications. The theoretical results are validated with measured values, and a good agreement prevailed. The results show that an increase in the plate oblique angle (γ) in the range from 0 to 15 degrees, leads to an increase in the Nusselt number (Nu) up to a maximum value and then decreases. The oblique angle at the maximum value of Nu depends on the flow Reynolds Number (Re), and (l w /l pl ), where (l w /l pl ) is defined as the ratio of the plates' spacing at zero oblique angle to the plate length. Furthermore, increasing (l w /l pl ) results in a significant increase in the heat transfer coefficient depending on the values of Re, and plate oblique angle (γ). In addition, increasing (γ) from 0 to 15 degrees results in a decrease in the friction factor up to a certain value, after which the friction value approaches a constant value depending on Re value and (l w /l pl ). It was found that for any value of the plate oblique angle (γ), the friction factor decreases with the increase of the values of (l w /l pl ) and Re, respectively.

Class I and II Small Heat Shock Proteins Together with HSP101 Protect Protein Translation Factors during Heat Stress.

Science.gov (United States)

McLoughlin, Fionn; Basha, Eman; Fowler, Mary E; Kim, Minsoo; Bordowitz, Juliana; Katiyar-Agarwal, Surekha; Vierling, Elizabeth

2016-10-01

The ubiquitous small heat shock proteins (sHSPs) are well documented to act in vitro as molecular chaperones to prevent the irreversible aggregation of heat-sensitive proteins. However, the in vivo activities of sHSPs remain unclear. To investigate the two most abundant classes of plant cytosolic sHSPs (class I [CI] and class II [CII]), RNA interference (RNAi) and overexpression lines were created in Arabidopsis (Arabidopsis thaliana) and shown to have reduced and enhanced tolerance, respectively, to extreme heat stress. Affinity purification of CI and CII sHSPs from heat-stressed seedlings recovered eukaryotic translation elongation factor (eEF) 1B (α-, β-, and γ-subunits) and eukaryotic translation initiation factor 4A (three isoforms), although the association with CI sHSPs was stronger and additional proteins involved in translation were recovered with CI sHSPs. eEF1B subunits became partially insoluble during heat stress and, in the CI and CII RNAi lines, showed reduced recovery to the soluble cell fraction after heat stress, which was also dependent on HSP101. Furthermore, after heat stress, CI sHSPs showed increased retention in the insoluble fraction in the CII RNAi line and vice versa. Immunolocalization revealed that both CI and CII sHSPs were present in cytosolic foci, some of which colocalized with HSP101 and with eEF1Bγ and eEF1Bβ. Thus, CI and CII sHSPs have both unique and overlapping functions and act either directly or indirectly to protect specific translation factors in cytosolic stress granules. © 2016 American Society of Plant Biologists. All Rights Reserved.

Design and development of hybrid energy generator (photovoltaics) with solar tracker

Science.gov (United States)

Mohiuddin, A. K. M.; Sabarudin, Mohamad Syabil Bin; Khan, Ahsan Ali; Izan Ihsan, Sany

2017-03-01

This paper is the outcome of a small scale hybrid energy generator (hydro and photovoltaic) project. It contains the photovoltaics part of the project. The demand of energy resources is increasing day by day. That is why people nowadays tend to move on and changes their energy usage from using fossil fuels to a cleaner and green energy like hydro energy, solar energy etc. Nevertheless, energy is hard to come by for people who live in remote areas and also campsites in the remote areas which need continuous energy sources to power the facilities. Thus, the purpose of this project is to design and develop a small scale hybrid energy generator to help people that are in need of power. This main objective of this project is to develop and analyze the effectiveness of solar trackers in order to increase the electricity generation from solar energy. Software like Solidworks and Arduino is used to sketch and construct the design and also to program the microcontroller respectively. Experimental results show the effectiveness of the designed solar tracker sytem.

Thin films of copper antimony sulfide: A photovoltaic absorber material

Energy Technology Data Exchange (ETDEWEB)

Ornelas-Acosta, R.E. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Shaji, S. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Krishnan, B., E-mail: kbindu_k@yahoo.com [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León (Mexico)

2015-01-15

Highlights: • CuSbS{sub 2} thin films were prepared by heating Sb{sub 2}S{sub 3}/Cu layers. • Analyzed the structure, composition, optical, and electrical properties. • PV structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag were formed at different conditions. • The PV parameters (J{sub sc}, V{sub oc}, and FF) were evaluated from the J–V characteristics. • J{sub sc}: 0.52–3.20 mA/cm{sup 2}, V{sub oc}:187–323 mV, FF: 0.27–0.48 were obtained. - Abstract: In this work, we report preparation and characterization of CuSbS{sub 2} thin films by heating glass/Sb{sub 2}S{sub 3}/Cu layers and their use as absorber material in photovoltaic structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag. The Sb{sub 2}S{sub 3} thin films of 600 nm were prepared by chemical bath deposition on which copper thin films of 50 nm were thermally evaporated, and the glass/Sb{sub 2}S{sub 3}/Cu multilayers were heated in vacuum at different temperatures. X-ray diffraction analysis showed the formation of orthorhombic CuSbS{sub 2} after heating the precursor layers. Studies on identification and chemical state of the elements were done using X-ray photoelectron spectroscopy. The optical band gap of the CuSbS{sub 2} thin films was 1.55 eV and the thin films were photoconductive. The photovoltaic parameters of the devices using CuSbS{sub 2} as absorber and CdS as window layer were evaluated from the J–V curves, yielding J{sub sc}, V{sub oc}, and FF values in the range of 0.52–3.20 mA/cm{sup 2}, 187–323 mV, and 0.27–0.48, respectively, under illumination of AM1.5 radiation.

Potential of HVAC and solar technologies for hospital retrofit to reduce heating energy consumption

Science.gov (United States)

Pop, Octavian G.; Abrudan, Ancuta C.; Adace, Dan S.; Pocola, Adrian G.; Balan, Mugur C.

2018-02-01

The study presents a combination of several energy efficient technologies together with their potential to reduce the energy consumption and to increase the comfort through the retrofit of a hospital building. The existing situation is characterized by an old and inefficient heating system, by the complete missing of any ventilation and by no cooling. The retrofit proposal includes thermal insulation and a distributed HVAC system consisting of several units that includes air to air heat exchangers and air to air heat pumps. A condensing boiler was also considered for heating. A solar thermal system for preparing domestic hot water and a solar photovoltaic system to assist the HVAC units are also proposed. Heat transfer principles are used for modelling the thermal response of the building to the environmental parameters and thermodynamic principles are used for modelling the behaviour of HVAC, solar thermal system and photovoltaic system. All the components of the heating loads were determined for one year period. The study reveals the capacity of the proposed systems to provide ventilation and thermal comfort with a global reduction of energy consumption of 71.6 %.

Standard Test Method for Determination of the Spectral Mismatch Parameter Between a Photovoltaic Device and a Photovoltaic Reference Cell

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This test method covers a procedure for the determination of a spectral mismatch parameter used in performance testing of photovoltaic devices. 1.2 The spectral mismatch parameter is a measure of the error, introduced in the testing of a photovoltaic device, caused by mismatch between the spectral responses of the photovoltaic device and the photovoltaic reference cell, as well as mismatch between the test light source and the reference spectral irradiance distribution to which the photovoltaic reference cell was calibrated. Examples of reference spectral irradiance distributions are Tables E490 or G173. 1.3 The spectral mismatch parameter can be used to correct photovoltaic performance data for spectral mismatch error. 1.4 This test method is intended for use with linear photovoltaic devices. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, a...

A kick to the photovoltaic industry

International Nuclear Information System (INIS)

Deye, M.; Remoue, A.

2010-01-01

In order to stop the speculation fever and to stabilize the photovoltaic trade, the French government has decided to lower some of the warranted electricity repurchase tariffs related to photovoltaic power generation. This announcement should have important impacts on the photovoltaic industry which will redirect its means and products towards the residential sector. (J.S.)

Process Development for Nanostructured Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Elam, Jeffrey W.

2015-01-01

Photovoltaic manufacturing is an emerging industry that promises a carbon-free, nearly limitless source of energy for our nation. However, the high-temperature manufacturing processes used for conventional silicon-based photovoltaics are extremely energy-intensive and expensive. This high cost imposes a critical barrier to the widespread implementation of photovoltaic technology. Argonne National Laboratory and its partners recently invented new methods for manufacturing nanostructured photovoltaic devices that allow dramatic savings in materials, process energy, and cost. These methods are based on atomic layer deposition, a thin film synthesis technique that has been commercialized for the mass production of semiconductor microelectronics. The goal of this project was to develop these low-cost fabrication methods for the high efficiency production of nanostructured photovoltaics, and to demonstrate these methods in solar cell manufacturing. We achieved this goal in two ways: 1) we demonstrated the benefits of these coatings in the laboratory by scaling-up the fabrication of low-cost dye sensitized solar cells; 2) we used our coating technology to reduce the manufacturing cost of solar cells under development by our industrial partners.

US Photovoltaic Patents, 1988--1990

Energy Technology Data Exchange (ETDEWEB)

1991-12-01

This document contains US patents on terrestrial photovoltaic (PV) power applications, including systems, components, and materials, as well as manufacturing and support functions. The patent entries in this document were issued from 1988 through 1990. The entries were located by searching USPA, the data base of the US Patent Office. The final search retrieved all patents under the class Batteries, Thermoelectric and Photoelectric'' and the subclasses Photoelectric,'' Testing,'' and Applications.'' The search also located patents that contained the words photovoltaic(s)'' or solar cell(s)'' and their derivatives. A manual search of the patents in the Solar Energy Research Institute (SERI) patent file augmented the data base search. After the initial list was compiled, most of the patents on the following subjects were excluded: space photovoltaic technology, use of the photovoltaic effect for detectors and subjects only peripherally concerned with photovoltaics. Some patents on these three subjects were included when it appeared that those inventions might be of use in terrestrial PV power technologies.

Survey of photovoltaic systems

Energy Technology Data Exchange (ETDEWEB)

1979-08-01

In developing this survey of photovoltaic systems, the University of Alabama in Huntsville assembled a task team to perform an extensive telephone survey of all known photovoltaic manufacturers. Three US companies accounted for 77% of the total domestic sales in 1978. They are Solarex Corporation, Solar Power Croporation, and ARCO Solar, Inc. This survey of solar photovoltaic (P/V) manufacturers and suppliers consists of three parts: a catalog of suppliers arranged alphabetically, data sheets on specific products, and typical operating, installation, or maintenance instructions and procedures. This report does not recommend or endorse any company product or information presented within as the results of this survey.

Photovoltaic barometer; Barometre photovoltaique

Energy Technology Data Exchange (ETDEWEB)

Anon.

2011-04-15

The photovoltaic sector is continuing on track, just as the extent of solar energy's electricity-generating potential is dawning on the public mind. The annual global installation figure was up more than twofold in 2010 (rising from just short of 7000 MWp in 2009). It leapt to over 16000 MWp, bringing worldwide installed photovoltaic capacity close to 38000 MWp. The photovoltaic power generated in the European Union at the end of 2010 reached 22.5 TWh which means an additional capacity of 13023 MWp during 2010. Concerning the cumulated installed capacity, Germany and Spain rank first and second in the European Union with respectively 17370 MWp and 3808 MWp

Radioisotope-powered photovoltaic generator

International Nuclear Information System (INIS)

McKlveen, J.W.; Uselman, J.

1979-01-01

Disposing of radioactive wastes from nuclear power plants has become one of the most important issues facing the nuclear industry. In a new concept, called a radioisotope photovoltaic generator, a portion of this waste would be used in conjunction with a scintillation material to produce light, with subsequent conversion into electricity via photovoltaic cells. Three types of scintillators and two types of silicon cells were tested in six combinations using 32 P as the radioisotope. The highest system efficiency, determined to be 0.5% when the light intensity was normalized to 100 mW/cm 2 , was obtained using a CsI crystal scintillator and a Helios photovoltaic cell

Effect of Aggregation on Squaraine Fullerene Bulk-Heterojunction Organic Photovoltaic Devices

Science.gov (United States)

Jalan, Ishita

Organic photovoltaics (OPV) offer great promise as a low-cost renewable energy source, the relative low efficiency still challenges its commercialization potential. Small conjugated molecules like Squaraine (SQ) molecules show promising advancement in organic photovoltaics (OPV). Advantages of SQ over other materials is that it has a high extinction coefficient (>105), decent photo-stability, good synthetic reproducibility, and tunable molecular structure. With small chemical modifications, the squaraines can have substantial impact on photophysical properties and aggregation pattern, and thus on operational OPV efficiency. The squaraine molecule that will be studied in this work is a symmetric aniline-based squaraine with n-hexyl chain on the molecular arm with di hydroxyl substituents on the aniline, this will be referred to DHSQ(OH) 2. In this work, the assignment of the monomer and aggregate peak is discussed. It is known that crystallinity is important for efficient charge transport and exciton diffusion in the BHJ, this thesis focuses on thermal and solvent vapor annealing the as-cast films to reduce the amorphous regions. It is observed that crystallinity is improved but often at the expense of larger crystal size. Therefore, to achieve optimal OPV efficiency, this tradeoff is controlled to improve the crystallinity while maintaining a small, highly mixed BHJ morphology.

Photovoltaic Subcontract Program

Energy Technology Data Exchange (ETDEWEB)

Surek, Thomas; Catalano, Anthony

1993-03-01

This report summarizes the fiscal year (FY) 1992 progress of the subcontracted photovoltaic (PV) research and development (R D) performed under the Photovoltaic Advanced Research and Development Project at the National Renewable Energy Laboratory (NREL)-formerly the Solar Energy Research Institute (SERI). The mission of the national PV program is to develop PV technology for large-scale generation of economically competitive electric power in the United States. The technical sections of the report cover the main areas of the subcontract program: the Crystalline Materials and Advanced Concepts project, the Polycrystalline Thin Films project, Amorphous Silicon Research project, the Photovoltaic Manufacturing Technology (PVMaT) project, PV Module and System Performance and Engineering project, and the PV Analysis and Applications Development project. Technical summaries of each of the subcontracted programs provide a discussion of approaches, major accomplishments in FY 1992, and future research directions.

A MARKETING STRATEGY ON PHOTOVOLTAIC MARKET

Directory of Open Access Journals (Sweden)

Coita Dorin Cristian

2008-05-01

Full Text Available Photovoltaic is an increasingly important energy technology. Deriving energy from the sun offers numerous environmental benefits. It is an extremely clean energy source, and few other power-generating technologies have as little environmental impact as photovoltaic. In this article we explored some dimensions of photovoltaic market and suggested a marketing strategy for solar panels manufacturers

Characterization of Single Phase and Two Phase Heat and Momentum Transport in a Spiraling Radial Inow Microchannel Heat Sink

Science.gov (United States)

Ruiz, Maritza

Thermal management of systems under high heat fluxes on the order of hundreds of W/cm2 is important for the safety, performance and lifetime of devices, with innovative cooling technologies leading to improved performance of electronics or concentrating solar photovoltaics. A novel, spiraling radial inflow microchannel heat sink for high flux cooling applications, using a single phase or vaporizing coolant, has demonstrated enhanced heat transfer capabilities. The design of the heat sink provides an inward swirl flow between parallel, coaxial disks that form a microchannel of 1 cm radius and 300 micron channel height with a single inlet and a single outlet. The channel is heated on one side through a conducting copper surface, and is essentially adiabatic on the opposite side to simulate a heat sink scenario for electronics or concentrated photovoltaics cooling. Experimental results on the heat transfer and pressure drop characteristics in the heat sink, using single phase water as a working fluid, revealed heat transfer enhancements due to flow acceleration and induced secondary flows when compared to unidirectional laminar fully developed flow between parallel plates. Additionally, thermal gradients on the surface are small relative to the bulk fluid temperature gain, a beneficial feature for high heat flux cooling applications. Heat flux levels of 113 W/cm2 at a surface temperature of 77 deg C were reached with a ratio of pumping power to heat rate of 0.03%. Analytical models on single phase flow are used to explore the parametric trends of the flow rate and passage geometry on the streamlines and pressure drop through the device. Flow boiling heat transfer and pressure drop characteristics were obtained for this heat sink using water at near atmospheric pressure as the working fluid for inlet subcooling levels ranging from 20 to 80 deg C and mean mass flux levels ranging from 184-716 kg/m. 2s. Flow enhancements similar to singlephase flow were expected, as well

Solution-processed, molecular photovoltaics that exploit hole transfer from non-fullerene, n-type materials

KAUST Repository

Douglas, Jessica D.; Chen, Mark S.; Niskala, Jeremy R.; Lee, Olivia P.; Yiu, Alan T.; Young, Eric P.; Frechet, Jean

2014-01-01

Solution-processed organic photovoltaic devices containing p-type and non-fullerene n-type small molecules obtain power conversion efficiencies as high as 2.4%. The optoelectronic properties of the n-type material BT(TTI-n12)2 allow these devices

Organic photovoltaics

Science.gov (United States)

Demming, Anna; Krebs, Frederik C.; Chen, Hongzheng

2013-12-01

successful solution processable organic photovoltaic devices at present. Andrey E Rudenko, Sangtaik Noh, and Barry C Thompson at the University of Southern California, Los Angeles, combine two approaches to broaden the absorption of conjugated polymers [3]. In atomistic bandgap control, a heavier chalcogen heteroatom is introduced into the aromatic repeat unit to decrease the HOMO-LUMO gap. In the semi-random donor-acceptor polymer architecture, small amounts of electron deficient monomers are incorporated at random. 'We have successfully established the concept of extending photon absorption through the combination of atomistic bandgap control and the donor-acceptor-based semi-random platform using a family of three new semi-random selenophene-based polymers', explain Thompson and colleagues. They add that the polymers exhibit extended and enhanced photon absorption compared with their polythiophene analogues while maintaining semicrystallinity. The benefits of various fabrication treatments are also reported, such as methanol rinsing for modifying the active layer interface [4] and annealing to achieve bicontinuous nanoscale phase separation for efficient exciton dissociation and charge collection [5]. The issue highlights how successfully structure and morphology can be manipulated to optimize solar-cell efficiencies while retaining advantageous material properties, with reports of innovative studies of bulk heterojunction [6-9] and inverse [10-13] structures, as well as innovative replacements for the traditional ITO transparent conducting electrode [14, 15]. Thomas Edison is famously quoted as saying 'I'd put my money on the Sun and solar energy, what a source of power! I hope we don't have to wait until oil and coal run out, before we tackle that'. Born in the wake of the industrial revolution when coal was king, the words seem strangely anachronistic and ahead of his time. As an undisputed genius of inventions it should not surprise us that he had such remarkable

Novel Materials for Photovoltaic Technologies: Preprint

International Nuclear Information System (INIS)

Alivisatos, P.; Carter, S.; Ginley, D.; Nozik, A.; Meyer, G.; Rosenthal, S.

1999-01-01

While existing photovoltaic technologies continue to advance, there are still many exciting opportunities in the area of novel materials. These opportunities arise because there is a substantial need for reducing the costs associated with the preparation and processing of photovoltaics, and because the theoretically possible photovoltaic efficiencies have yet to be achieved in practical devices. Thus it remains reasonable to continue photovoltaic research activity aimed at entirely new approaches to processing and at entirely new materials as the active media. This group identified three areas for further consideration: (a) Nano/molecular composites and hierarchical structures; (b) Organic semiconductors; and (c) Hot carrier devices

Graphite-based photovoltaic cells

Science.gov (United States)

Lagally, Max; Liu, Feng

2010-12-28

The present invention uses lithographically patterned graphite stacks as the basic building elements of an efficient and economical photovoltaic cell. The basic design of the graphite-based photovoltaic cells includes a plurality of spatially separated graphite stacks, each comprising a plurality of vertically stacked, semiconducting graphene sheets (carbon nanoribbons) bridging electrically conductive contacts.

System design optimization for stand-alone photovoltaic systems sizing by using superstructure model

International Nuclear Information System (INIS)

Azau, M A M; Jaafar, S; Samsudin, K

2013-01-01

Although the photovoltaic (PV) systems have been increasingly installed as an alternative and renewable green power generation, the initial set up cost, maintenance cost and equipment mismatch are some of the key issues that slows down the installation in small household. This paper presents the design optimization of stand-alone photovoltaic systems using superstructure model where all possible types of technology of the equipment are captured and life cycle cost analysis is formulated as a mixed integer programming (MIP). A model for investment planning of power generation and long-term decision model are developed in order to help the system engineer to build a cost effective system.

Chalcogenide glass-ceramic with self-organized heterojunctions: application to photovoltaic solar cells

Science.gov (United States)

Zhang, Xianghua; Korolkov, Ilia; Fan, Bo; Cathelinaud, Michel; Ma, Hongli; Adam, Jean-Luc; Merdrignac, Odile; Calvez, Laurent; Lhermite, Hervé; Brizoual, Laurent Le; Pasquinelli, Marcel; Simon, Jean-Jacques

2018-03-01

In this work, we present for the first time the concept of chalcogenide glass-ceramic for photovoltaic applications with the GeSe2-Sb2Se3-CuI system. It has been demonstrated that thin films, deposited with the sputtering technique, are amorphous and can be crystallized with appropriate heat treatment. The thin film glass-ceramic behaves as a p-type semiconductor, even if it contains p-type Cu2GeSe3 and n-type Sb2Se3. The conductivity of Sb2Se3 has been greatly improved by appropriate iodine doping. The first photovoltaic solar cells based on the association of iodine-doped Sb2Se3 and the glass-ceramic thin films give a short-circuit current density JSC of 10 mA/cm2 and an open-circuit voltage VOC of 255 mV, with a power conversion efficiency of about 0.9%.

Desalination using low grade heat sources

Science.gov (United States)

Gude, Veera Gnaneswar

A new, low temperature, energy-efficient and sustainable desalination system has been developed in this research. This system operates under near-vacuum conditions created by exploiting natural means of gravity and barometric pressure head. The system can be driven by low grade heat sources such as solar energy or waste heat streams. Both theoretical and experimental studies were conducted under this research to evaluate and demonstrate the feasibility of the proposed process. Theoretical studies included thermodynamic analysis and process modeling to evaluate the performance of the process using the following alternate energy sources for driving the process: solar thermal energy, solar photovoltaic/thermal energy, geothermal energy, and process waste heat emissions. Experimental studies included prototype scale demonstration of the process using grid power as well as solar photovoltaic/thermal sources. Finally, the feasibility of the process in reclaiming potable-quality water from the effluent of the city wastewater treatment plant was studied. The following results have been obtained from theoretical analysis and modeling: (1) The proposed process can produce up to 8 L/d of freshwater for 1 m2 area of solar collector and evaporation chamber respectively with a specific energy requirement of 3122 kJ for 1 kg of freshwater production. (2) Photovoltaic/thermal (PV/T) energy can produce up to 200 L/d of freshwater with a 25 m2 PV/T module which meets the electricity needs of 21 kWh/d of a typical household as well. This configuration requires a specific energy of 3122 kJ for 1 kg of freshwater production. (3) 100 kg/hr of geothermal water at 60°C as heat source can produce up to 60 L/d of freshwater with a specific energy requirement of 3078 kJ for 1 kg of freshwater production. (4) Waste heat released from an air conditioning system rated at 3.25 kW cooling, can produce up to 125 L/d of freshwater. This configuration requires an additional energy of 208 kJ/kg of

Small-Scale Pellet Heating Systems from Consumer Perspective

Energy Technology Data Exchange (ETDEWEB)

Mahapatra, K; Gustavsson, L [Mid Sweden Univ., Oestersund (Sweden). Ecotechnology

2006-07-15

A questionnaire survey of 1,500 detached house owners was carried out in the autumn of 2004 to find out the factors influencing the adoption and diffusion of pellet heating systems in the Swedish residential sector. The results revealed that most of the respondents had no plans to install new heating systems as they were satisfied with their existing ones. Economic aspects and functional reliability were the most important factors in the respondents' choice of heating system while environmental factors were of less importance. Therefore, internalizing external costs, such as environmental costs, might be effective in influencing house owners to adopt environmentally benign heating systems. Installers were the most important source of information on heating systems. Hence, it is important that they could inform the consumers comprehensively and accurately about different heating systems. Respondents perceived the relative advantage of pellet boilers over oil or electricity-based heating systems, but bedrock heat pump system was ranked higher than pellet heating system in every aspect except for investment cost. Pellet heating system has advantage over district heating system with respect to investment cost and annual cost of heating. District heating system was considered as most functionally reliable and automatic.

Small-Scale Pellet Heating Systems from Consumer Perspective

International Nuclear Information System (INIS)

Mahapatra, K.; Gustavsson, L.

2006-01-01

A questionnaire survey of 1,500 detached house owners was carried out in the autumn of 2004 to find out the factors influencing the adoption and diffusion of pellet heating systems in the Swedish residential sector. The results revealed that most of the respondents had no plans to install new heating systems as they were satisfied with their existing ones. Economic aspects and functional reliability were the most important factors in the respondents' choice of heating system while environmental factors were of less importance. Therefore, internalizing external costs, such as environmental costs, might be effective in influencing house owners to adopt environmentally benign heating systems. Installers were the most important source of information on heating systems. Hence, it is important that they could inform the consumers comprehensively and accurately about different heating systems. Respondents perceived the relative advantage of pellet boilers over oil or electricity-based heating systems, but bedrock heat pump system was ranked higher than pellet heating system in every aspect except for investment cost. Pellet heating system has advantage over district heating system with respect to investment cost and annual cost of heating. District heating system was considered as most functionally reliable and automatic

Photovoltaic energy barometer

International Nuclear Information System (INIS)

Anon

2006-01-01

The european market showed all of its strength and soundness in 2005. The 2005 installed cells growth could have been even greater if the market had not been continually curbed by a lack of raw materials. Germany remained the leading photovoltaic market in the world in 2005, positioned far ahead of Japan and the USA. This unabashed success inspired both Spain and Italy, which set up conditions in order to rapidly develop their photovoltaic sectors. (A.L.B.)

Contribution of Jahn-Teller and charge transfer excitations to the photovoltaic effect of manganite/titanite heterojunctions

Science.gov (United States)

Ifland, Benedikt; Hoffmann, Joerg; Kressdorf, Birte; Roddatis, Vladimir; Seibt, Michael; Jooss, Christian

2017-06-01

The effect of correlation effects on photovoltaic energy conversion at manganite/titanite heterojunctions is investigated. As a model system we choose a heterostructure consisting of the small polaron absorber Pr0.66Ca0.34MnO3 (PCMO) epitaxially grown on single-crystalline Nb-doped SrTi0.998Nb0.002O3 (STNO) substrates. The high structural and chemical quality of the interfaces is proved by detailed characterization using high-resolution transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) studies. Spectrally resolved and temperature-dependent photovoltaic measurements show pronounced contributions of both the Jahn-Teller (JT) excitations and the charge transfer (CT) transitions to the photovoltaic effect at different photon energies. A linear temperature dependence of the open-circuit voltage for an excitation in the PCMO manganite is only observed below the charge-ordering temperature, indicating that the diffusion length of the photocarrier exceeds the size of the space charge region. The photovoltaic response is compared to that of a heterojunction of lightly doped Pr0.05Ca0.95MnO3 (CMO)/STNO, where the JT transition is absent. Here, significant contributions of the CT transition to the photovoltaic effect set in below the Neel temperature. We conclude that polaronic correlations and ordering effects are essentials for photovoltaic energy conversion in manganites.

Photovoltaic policy is questioned

International Nuclear Information System (INIS)

Piro, P.; Cessac, M.

2011-01-01

The French government has decided a freeze and a reassessment of the measures taken to support the photovoltaic sector. Only the installations with a power output over 3 kWc are concerned so the market of solar roofs for homes is spared. The main reasons for this reversal is the quick and chaotic development of photovoltaic projects, a lot of projects are only motivated by the lure of high purchase prices of the electricity produced imposed by the law on EDF. Another reason is that 90% of the solar panels installed in France come from China, the photovoltaic sector retorts that 75% of the price of a complete installation pays for services produced in France. (A.C.)

Is organic photovoltaics promising for indoor applications?

Energy Technology Data Exchange (ETDEWEB)

Lee, Harrison K. H.; Li, Zhe; Tsoi, Wing C., E-mail: w.c.tsoi@swansea.ac.uk [SPECIFIC, College of Engineering, Bay Campus, Swansea University, SA1 8EN Swansea (United Kingdom); Durrant, James R. [SPECIFIC, College of Engineering, Bay Campus, Swansea University, SA1 8EN Swansea (United Kingdom); Department of Chemistry, Imperial College London, SW7 2AZ London (United Kingdom)

2016-06-20

This work utilizes organic photovoltaics (OPV) for indoor applications, such as powering small electronic devices or wireless connected Internet of Things. Three representative polymer-based OPV systems, namely, poly(3-hexylthiophene-2,5-diyl), poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′, 1′,3′-benzothiadiazole)], and poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

Is organic photovoltaics promising for indoor applications?

International Nuclear Information System (INIS)

Lee, Harrison K. H.; Li, Zhe; Tsoi, Wing C.; Durrant, James R.

2016-01-01

This work utilizes organic photovoltaics (OPV) for indoor applications, such as powering small electronic devices or wireless connected Internet of Things. Three representative polymer-based OPV systems, namely, poly(3-hexylthiophene-2,5-diyl), poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′, 1′,3′-benzothiadiazole)], and poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

Interface modification of organic photovoltaics by combining molybdenum oxide (MoO{sub x}) and molecular template layer

Energy Technology Data Exchange (ETDEWEB)

Duan, Haichao [Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Yang, Junliang, E-mail: junliang.yang@csu.edu.cn [Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Fu, Lin; Xiong, Jian; Yang, Bingchu; Ouyang, Jun; Zhou, Conghua; Huang, Han [Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Gao, Yongli [Institute of Super-microstructure and Ultrafast Process in Advanced Materials, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan 410083 (China); Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)

2015-01-01

We report discrete heterojunction small molecular organic photovoltaics (OPVs) with enhanced performance by modifying the interface using molybdenum oxide (MoO{sub x}) and molecular template layer perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride (PTCDA). A large increase in open-circuit voltage was obtained in copper phthalocyanine/fullerene, i.e., CuPc/C{sub 60} and CuPc/PCBM, discrete planar heterojunction photovoltaics with an insertion of 5 nm MoO{sub x} hole transport layer at the interface between the anode electrode and the CuPc donor layer. It results from the band bending at the interface and the pinning of the highest occupied molecular orbital level of CuPc to the Fermi level of MoO{sub x} due to the defect states (oxygen vacancies) in MoO{sub x} thin films. Moreover, the short-circuit current showed an efficient improvement by inserting a 1 nm PTCDA layer at the interface between the MoO{sub x} layer and the CuPc layer. The PTCDA layer induces the growth of CuPc thin film with lying-down molecular arrangement, supporting the charge transports along the vertical direction. The power conversion efficiencies of CuPc/C{sub 60} and CuPc/PCBM discrete planar heterojunction photovoltaic devices were improved from about 0.80% to 1.50% with inserting both MoO{sub x} and PTCDA layers. The results suggest that the performance of organic discrete planar heterojunction photovoltaics could be optimized by interface modification with combining hole transport layer and molecular template layer, which are potentially suitable for other highly efficient OPVs, such as small molecular tandem OPVs. - Highlights: • Organic small molecule photovoltaics were fabricated by interface modification. • An inserted molybdenum oxide layer largely enhances open-circuit voltage. • An inserted molecular template layer dramatically improves short-circuit current. • The power conversion efficiencies are almost doubled with interface modification.

Optimal sizing of utility-scale photovoltaic power generation complementarily operating with hydropower: A case study of the world’s largest hydro-photovoltaic plant

International Nuclear Information System (INIS)

Fang, Wei; Huang, Qiang; Huang, Shengzhi; Yang, Jie; Meng, Erhao; Li, Yunyun

2017-01-01

Highlights: • Feasibility of complementary hydro-photovoltaic operation across the world is revealed. • Three scenarios of the novel operation mode are proposed to satisfy different load demand. • A method for optimally sizing a utility-scale photovoltaic plant is developed by maximizing the net revenue during lifetime. • The influence of complementary hydro-photovoltaic operation upon water resources allocation is investigated. - Abstract: The high variability of solar energy makes utility-scale photovoltaic power generation confront huge challenges to penetrate into power system. In this paper, the complementary hydro-photovoltaic operation is explored, aiming at improving the power quality of photovoltaic and promoting the integration of photovoltaic into the system. First, solar-rich and hydro-rich regions across the world are revealed, which are suitable for implementing the complementary hydro-photovoltaic operation. Then, three practical scenarios of the novel operation mode are proposed for better satisfying different types of load demand. Moreover, a method for optimal sizing of a photovoltaic plant integrated into a hydropower plant is developed by maximizing the net revenue during lifetime. Longyangxia complementary hydro-photovoltaic project, the current world’s largest hydro-photovoltaic power plant, is selected as a case study and its optimal photovoltaic capacities of different scenarios are calculated. Results indicate that hydropower installed capacity and annual solar curtailment rate play crucial roles in the size optimization of a photovoltaic plant and complementary hydro-photovoltaic operation exerts little adverse effect upon the water resources allocation of Longyangxia reservoir. The novel operation mode not only improves the penetration of utility-scale photovoltaic power generation but also can provide a valuable reference for the large-scale utilization of other kinds of renewable energy worldwide.

Photovoltaic Technology and Applications | Othieno | Discovery and ...

African Journals Online (AJOL)

Photovoltaic home systems appear to be the most viable alternative source of electricity. The photovoltaic technology is therefore reviewed and recommendations made on their application for rural electrification in the developing nations. Keywords: solar energy, photovoltaic materials, electrification, rural power, cost, ...

Photorefraction in crystals with nonstationary photovoltaic current

International Nuclear Information System (INIS)

Volk, T.R.; Astaf'ev, S.B.; Razumovskij, N.V.

1995-01-01

Effect of photovoltaic current nonstationary components, conditioned by nonstationary character of photovoltaic centers, on photorefractive properties of LiNbO 3 crystals is considered. Analytic expressions describing nonstationary photovoltaic current effect on kinetics of recording and optical erasure of photorefraction are obtained. A possibility of nonstationary photovoltaic current occurrence in crystals with multilevel charge transfer circuit is considered. Recording light pulse duration effect on photorefraction in LiNbO 3 is discussed. 25 refs., 8 figs

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.

Steam generator concept of a small HTR for reheating and for removal of the residual heat

Energy Technology Data Exchange (ETDEWEB)

Singh, J; Barnert, H; Hohn, H; Mondry, M [Institut fuer Reaktorenentwicklung, Kernforschungsanlage Juelich GmbH, Juelich (Germany)

1988-07-01

The steam generator of a small HTR is arranged above the core in an in line design of the primary loop, thereby helium flows upwards. Water flows downwards in the steam generator to realize cross flow. To achieve stable evaporation conditions during part load operation it is desired to realize upward evaporation in the steam generator. Moreover if the steam generator is also used as a heat sink for removal of residual heat, this desire of upwards evaporation becomes more imperative. It is possible to realize the design of steam generator with upwards evaporation by arranging a hot gas duct in its central region, so that hot helium can flow upwards through it. Therefore helium enters the steam generator from the top and flows downwards and water upwards. In the presented design, a heat exchanger is arranged in the central region of the steam generator instead of a hot gas duct. Hot helium of 750 deg. C flows upwards in this heat exchanger and thereby cools down to the temperature of about 700 deg. C before it enters the bundle of the steam generator at the top. Through an intermediate loop this heat is transferred outside the primary loop, where in an extra heat exchanger live steam is reheated to improve the thermal efficiency of the plant. This intermediate loop works on the basis of forced convection and transfer about 25 MW for reheating. During the shutdown operation of the reactor, this heat exchanger in the central region of the steam generator serves as a heat sink for removal of the residual heat through natural convection in the primary loop. At the same time it is further possible, that intermediate loop also works on the basis of natural convection, because during shutdown operation only a very small amount of heat has to be removed and moreover the outside heat exchanger can be arranged much higher above the central heat exchanger to get favourable conditions for the natural convection. Some of the highlights of the central heat exchanger are: coaxial

Energizing architecture. Design and photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Lueling, Claudia (ed.)

2009-07-01

Power generation by photovoltaic systems and buildings is much more than just an alternative to traditional electric power generation. As the planning and design of photovoltaics is increasingly shifting to the forefront, it is rapidly becoming a new challenge for architecture. This book describes the whole spectrum of possible applications - from inspiration to detail - of photovoltaics as an integral part of building envelopes and introduces groundbreaking examples and visions for the future, in which photovoltaic elements work as a successful part of exterior facades - combined with highly luminous and economical illuminated wallpaper and curtains inside buildings. Its range extends from early designs by artists such as Daniel Hausig to aspects of material selection to detail drawings of implemented solutions. The enormous variety of possible applications of this new (building) material demonstrates the huge potential it possesses. (orig.)

A sensitivity analysis of central flat-plate photovoltaic systems and implications for national photovoltaics program planning

Science.gov (United States)

Crosetti, M. R.

1985-01-01

The sensitivity of the National Photovoltaic Research Program goals to changes in individual photovoltaic system parameters is explored. Using the relationship between lifetime cost and system performance parameters, tests were made to see how overall photovoltaic system energy costs are affected by changes in the goals set for module cost and efficiency, system component costs and efficiencies, operation and maintenance costs, and indirect costs. The results are presented in tables and figures for easy reference.

A thermal model for photovoltaic panels under varying atmospheric conditions

International Nuclear Information System (INIS)

Armstrong, S.; Hurley, W.G.

2010-01-01

The response of the photovoltaic (PV) panel temperature is dynamic with respect to the changes in the incoming solar radiation. During periods of rapidly changing conditions, a steady state model of the operating temperature cannot be justified because the response time of the PV panel temperature becomes significant due to its large thermal mass. Therefore, it is of interest to determine the thermal response time of the PV panel. Previous attempts to determine the thermal response time have used indoor measurements, controlling the wind flow over the surface of the panel with fans or conducting the experiments in darkness to avoid radiative heat loss effects. In real operating conditions, the effective PV panel temperature is subjected to randomly varying ambient temperature and fluctuating wind speeds and directions; parameters that are not replicated in controlled, indoor experiments. A new thermal model is proposed that incorporates atmospheric conditions; effects of PV panel material composition and mounting structure. Experimental results are presented which verify the thermal behaviour of a photovoltaic panel for low to strong winds.

Overview of new-generation photovoltaic technologies

International Nuclear Information System (INIS)

Della Sala, D.; Moro, A.; Fidanza, A.; Di Francia, G.; Giorgi, R.

2008-01-01

The number of photovoltaic installation is rising in Italy, but they are all based on imported technologies. This article describes some new types of photovoltaic cells that benefit from powerful synergies with other sectors. ENEA can help speed their development by exploiting its long experience with photovoltaic and the growing body of know-how on the new frontiers of electronics and new materials [it

Optimization of photovoltaic power systems

CERN Document Server

Rekioua, Djamila

2012-01-01

Photovoltaic generation is one of the cleanest forms of energy conversion available. One of the advantages offered by solar energy is its potential to provide sustainable electricity in areas not served by the conventional power grid. Optimisation of Photovoltaic Power Systems details explicit modelling, control and optimisation of the most popular stand-alone applications such as pumping, power supply, and desalination. Each section is concluded by an example using the MATLAB(R) and Simulink(R) packages to help the reader understand and evaluate the performance of different photovoltaic syste

Silicon processing for photovoltaics II