New directions for space solar power

Science.gov (United States)

Mankins, John C.

2009-07-01

Several of the central issues associated with the eventual realization of the vision of solar power from space for terrestrial markets resolve around the expect costs associated with the assembly, inspection, maintenance and repair of future solar power satellite (SPS) stations. In past studies (for example, NASA's "Fresh Look Study", c. 1995-1997) efforts were made to reduce both the scale and mass of large, systems-level interfaces (e.g., the power management and distribution (PMAD) system) and on-orbit fixed infrastructures through the use of modular systems strategies. These efforts have had mixed success (as reflected in the projected on-orbit mass of various systems concepts. However, the author remains convinced of the importance of modular strategies for exceptionally large space systems in eventually realizing the vision of power from space. This paper will introduce some of the key issues associated with cost-competitive space solar power in terrestrial markets. It will examine some of the relevant SPS concepts and will assess the 'pros and cons' of each in terms of space assembly, maintenance and servicing (SAMS) requirements. The paper discusses at a high level some relevant concepts and technologies that may play r role in the eventual, successful resolution of these challenges. The paper concludes with an example of the kind of novel architectural approach for space solar power that is needed.

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

International Nuclear Information System (INIS)

Geyer, Michael; Quaschning, Volker

2000-01-01

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

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

Science.gov (United States)

1979-01-01

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

Concentrating Solar Power Projects - Khi Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL Khi Solar One This page provides information on Khi Solar One, a concentrating solar power (CSP) project, with data organized by background, parcipants and power plant configuration . Status Date: February 8, 2016 Project Overview Project Name: Khi Solar One Country: South Africa Location

Parabolic Trough Solar Power for Competitive U.S. Markets

International Nuclear Information System (INIS)

Price, Henry W.

1998-01-01

Nine parabolic trough power plants located in the California Mojave Desert represent the only commercial development of large-scale solar power plants to date. Although all nine plants continue to operate today, no new solar power plants have been completed since 1990. Over the last several years, the parabolic trough industry has focused much of its efforts on international market opportunities. Although the power market in developing countries appears to offer a number of opportunities for parabolic trough technologies due to high growth and the availability of special financial incentives for renewables, these markets are also plagued with many difficulties for developers. In recent years, there has been some renewed interest in the U.S. domestic power market as a result of an emerging green market and green pricing incentives. Unfortunately, many of these market opportunities and incentives focus on smaller, more modular technologies (such as photovoltaics or wind power), and as a result they tend to exclude or are of minimum long-term benefit to large-scale concentrating solar power technologies. This paper looks at what is necessary for large-scale parabolic trough solar power plants to compete with state-of-the-art fossil power technology in a competitive U.S. power market

Concentrating Solar Power. Report April 2009

Energy Technology Data Exchange (ETDEWEB)

Pihl, Erik (Chalmers Univ. of Technology, Enery and Environment, Goeteborg (Sweden))

2009-04-15

Concentrating solar power (CSP) technologies offer ways to utilise solar radiation by concentrating the light. In a concentrated form, the light can be utilised more cost efficiently. It is focused with mirrors or lenses and used either as a heat source in thermal power cycles (thermal CSP) or as a light source for high efficiency photovoltaic cells (concentrating photovoltaics, CPV). All concentrating systems use tracking to follow the movement of the sun, in two or three dimensions, and require direct sunlight (no diffusing clouds). CSP plants are often more complex, component wise than those based on flat PV. The extra cost of complexity is generally more than offset by the larger scales, the less need for expensive materials such as purified silicon and a better fit with the current energy infrastructure. Some thermal CSP plants offer great possibilities to deal with the intermittency of solar energy, as the heat generated can be stored in the form of a heated liquid in large tanks for many hours with little additional cost, and drive the thermal power generation also during cloudy periods or at night. CSP is growing rapidly and can be an important portion of future low-carbon energy systems. A prerequisite is that expected cost reductions are, at least largely, realised. In regions with good solar conditions (Mediterranean countries, US Southwest, Middle East, Australia etc), CSP systems already in the short-term future can satisfy significant shares of the power demand, to decrease CO{sub 2} emissions. Less solar-intensive regions (Northern Europe, much of North America etc) can be supplied with CSP power from solar-rich regions by using long distance power grids, for instance the high voltage DC cables being deployed and developed today

Concentrating Solar Power Projects - Nevada Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL Nevada Solar One This page provides information on Nevada Solar One, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. Acciona Energy's Nevada Solar One is the third largest CSP plant in the world and the first plant

The place of solar power: an economic analysis of concentrated and distributed solar power.

Science.gov (United States)

Banoni, Vanessa Arellano; Arnone, Aldo; Fondeur, Maria; Hodge, Annabel; Offner, J Patrick; Phillips, Jordan K

2012-04-23

This paper examines the cost and benefits, both financial and environmental, of two leading forms of solar power generation, grid-tied photovoltaic cells and Dish Stirling Systems, using conventional carbon-based fuel as a benchmark. First we define how these solar technologies will be implemented and why. Then we delineate a model city and its characteristics, which will be used to test the two methods of solar-powered electric distribution. Then we set the constraining assumptions for each technology, which serve as parameters for our calculations. Finally, we calculate the present value of the total cost of conventional energy needed to power our model city and use this as a benchmark when analyzing both solar models' benefits and costs. The preeminent form of distributed electricity generation, grid-tied photovoltaic cells under net-metering, allow individual homeowners a degree of electric self-sufficiency while often turning a profit. However, substantial subsidies are required to make the investment sensible. Meanwhile, large dish Stirling engine installations have a significantly higher potential rate of return, but face a number of pragmatic limitations. This paper concludes that both technologies are a sensible investment for consumers, but given that the dish Stirling consumer receives 6.37 dollars per watt while the home photovoltaic system consumer receives between 0.9 and 1.70 dollars per watt, the former appears to be a superior option. Despite the large investment, this paper deduces that it is far more feasible to get few strong investors to develop a solar farm of this magnitude, than to get 150,000 households to install photovoltaic arrays in their roofs. Potential implications of the solar farm construction include an environmental impact given the size of land require for this endeavour. However, the positive aspects, which include a large CO2 emission reduction aggregated over the lifespan of the farm, outweigh any minor concerns or potential

The place of solar power: an economic analysis of concentrated and distributed solar power

Directory of Open Access Journals (Sweden)

Banoni Vanessa

2012-04-01

Full Text Available Abstract Background This paper examines the cost and benefits, both financial and environmental, of two leading forms of solar power generation, grid-tied photovoltaic cells and Dish Stirling Systems, using conventional carbon-based fuel as a benchmark. Methods First we define how these solar technologies will be implemented and why. Then we delineate a model city and its characteristics, which will be used to test the two methods of solar-powered electric distribution. Then we set the constraining assumptions for each technology, which serve as parameters for our calculations. Finally, we calculate the present value of the total cost of conventional energy needed to power our model city and use this as a benchmark when analyzing both solar models’ benefits and costs. Results The preeminent form of distributed electricity generation, grid-tied photovoltaic cells under net-metering, allow individual homeowners a degree of electric self-sufficiency while often turning a profit. However, substantial subsidies are required to make the investment sensible. Meanwhile, large dish Stirling engine installations have a significantly higher potential rate of return, but face a number of pragmatic limitations. Conclusions This paper concludes that both technologies are a sensible investment for consumers, but given that the dish Stirling consumer receives 6.37 dollars per watt while the home photovoltaic system consumer receives between 0.9 and 1.70 dollars per watt, the former appears to be a superior option. Despite the large investment, this paper deduces that it is far more feasible to get few strong investors to develop a solar farm of this magnitude, than to get 150,000 households to install photovoltaic arrays in their roofs. Potential implications of the solar farm construction include an environmental impact given the size of land require for this endeavour. However, the positive aspects, which include a large CO2 emission reduction aggregated

The place of solar power: an economic analysis of concentrated and distributed solar power

Science.gov (United States)

2012-01-01

Background This paper examines the cost and benefits, both financial and environmental, of two leading forms of solar power generation, grid-tied photovoltaic cells and Dish Stirling Systems, using conventional carbon-based fuel as a benchmark. Methods First we define how these solar technologies will be implemented and why. Then we delineate a model city and its characteristics, which will be used to test the two methods of solar-powered electric distribution. Then we set the constraining assumptions for each technology, which serve as parameters for our calculations. Finally, we calculate the present value of the total cost of conventional energy needed to power our model city and use this as a benchmark when analyzing both solar models’ benefits and costs. Results The preeminent form of distributed electricity generation, grid-tied photovoltaic cells under net-metering, allow individual homeowners a degree of electric self-sufficiency while often turning a profit. However, substantial subsidies are required to make the investment sensible. Meanwhile, large dish Stirling engine installations have a significantly higher potential rate of return, but face a number of pragmatic limitations. Conclusions This paper concludes that both technologies are a sensible investment for consumers, but given that the dish Stirling consumer receives 6.37 dollars per watt while the home photovoltaic system consumer receives between 0.9 and 1.70 dollars per watt, the former appears to be a superior option. Despite the large investment, this paper deduces that it is far more feasible to get few strong investors to develop a solar farm of this magnitude, than to get 150,000 households to install photovoltaic arrays in their roofs. Potential implications of the solar farm construction include an environmental impact given the size of land require for this endeavour. However, the positive aspects, which include a large CO2 emission reduction aggregated over the lifespan of the farm

Heat Transfer Phenomena in Concentrating Solar Power Systems.

Energy Technology Data Exchange (ETDEWEB)

Armijo, Kenneth Miguel; Shinde, Subhash L.

2016-11-01

Concentrating solar power (CSP) utilizes solar thermal energy to drive a thermal power cycle for the generation of electricity. CSP systems are facilitated as large, centralized power plants , such as power towers and trough systems, to take advantage of ec onomies of scale through dispatchable thermal energy storage, which is a principle advantage over other energy generation systems . Additionally, the combination of large solar concentration ratios with high solar conversion efficiencies provides a strong o pportunity of employment of specific power cycles such as the Brayton gas cycle that utilizes super critical fluids such as supercritical carbon dioxide (s CO 2 ) , compared to other sola r - fossil hybrid power plants. A comprehensive thermal - fluids examination is provided by this work of various heat transfer phenomena evident in CSP technologies. These include sub - systems and heat transfer fundamental phenomena evident within CSP systems , which include s receivers, heat transfer fluids (HTFs), thermal storage me dia and system designs , thermodynamic power block systems/components, as well as high - temperature materials. This work provides literature reviews, trade studies, and phenomenological comparisons of heat transfer media (HTM) and components and systems, all for promotion of high performance and efficient CSP systems. In addition, f urther investigations are also conducted that provide advanced heat transfer modeling approaches for gas - particle receiver systems , as well as performance/efficiency enhancement re commendations, particularly for solarized supercritical power systems .

Economic analysis of power generation from floating solar chimney power plant

International Nuclear Information System (INIS)

Zhou, Xinping; Yang, Jiakuan; Xiao, Bo; Wang, Fen

2009-01-01

Solar chimney thermal power technology that has a long life span is a promising large-scale solar power generating technology. This paper performs economic analysis of power generation from floating solar chimney power plant (FSCPP) by analyzing cash flows during the whole service period of a 100 MW plant. Cash flows are influenced by many factors including investment, operation and maintenance cost, life span, payback period, inflation rate, minimum attractive rate of return, non-returnable subsidy rate, interest rate of loans, sale price of electricity, income tax rate and whether additional revenue generated by carbon credits is included or not. Financial incentives and additional revenue generated by carbon credits can accelerate the development of the FSCPP. Sensitivity analysis to examine the effects of the factors on cash flows of a 100 MW FSCPP is performed in detail. The results show that the minimum price for obtaining minimum attractive rate of return (MARR) of 8% reaches 0.83 yuan (kWh) -1 under financial incentives including loans at a low interest rate of 2% and free income tax. Comparisons of economics of the FSCPP and reinforced concrete solar chimney power plant or solar photovoltaic plant are also performed by analyzing their cash flows. It is concluded that FSCPP is in reality more economical than reinforced concrete solar chimney power plant (RCSCPP) or solar photovoltaic plant (SPVP) with the same power capacity. (author)

Techno-economic analysis of large-scale integration of solar power plants in the European grid

Energy Technology Data Exchange (ETDEWEB)

Tielens, Pieter; Ergun, Hakan; Hertem, Dirk van [Katholieke Universiteit Leuven (Belgium). Electrical Engineering Dept.

2012-07-01

In this paper different options to connect large solar power plants in North Africa to the European power system are compared from a transmission system investment point of view. Three different possible DC connections from Tunisia to Italy are investigated from a cost-based perspective. In the second part of the paper, the impact of the power fluctuations from CSP and PV power plants on the frequency control is examined in a qualitative manner. It is shown that the frequency response mainly depends on the amount of PV installed and the inertia present in the grid. The results of the simulations give a first estimation of the maximum amount of PV integration in the Tunisian grid without reaching certain frequency limits after a sudden power fluctuation. (orig.)

Concentrated solar power generation using solar receivers

Science.gov (United States)

Anderson, Bruce N.; Treece, William Dean; Brown, Dan; Bennhold, Florian; Hilgert, Christoph

2017-08-08

Inventive concentrated solar power systems using solar receivers, and related devices and methods, are generally described. Low pressure solar receivers are provided that function to convert solar radiation energy to thermal energy of a working fluid, e.g., a working fluid of a power generation or thermal storage system. In some embodiments, low pressure solar receivers are provided herein that are useful in conjunction with gas turbine based power generation systems.

Facing technological challenges of Solar Updraft Power Plants

Science.gov (United States)

Lupi, F.; Borri, C.; Harte, R.; Krätzig, W. B.; Niemann, H.-J.

2015-01-01

The Solar Updraft Power Plant technology addresses a very challenging idea of combining two kinds of renewable energy: wind and solar. The working principle is simple: a Solar Updraft Power Plant (SUPP) consists of a collector area to heat the air due to the wide-banded ultra-violet solar radiation, the high-rise solar tower to updraft the heated air to the atmosphere, and in between the power conversion unit, where a system of coupled turbines and generators transforms the stream of heated air into electric power. A good efficiency of the power plant can only be reached with extra-large dimensions of the tower and/or the collector area. The paper presents an up-to-date review of the SUPP technology, focusing on the multi-physics modeling of the power plant, on the structural behavior of the tower and, last but not least, on the modeling of the stochastic wind loading process.

Grid-connected distributed solar power systems

Science.gov (United States)

Moyle, R.; Chernoff, H.; Schweizer, T.

This paper discusses some important, though often ignored, technical and economic issues of distributed solar power systems: protection of the utility system and nonsolar customers requires suitable interfaced equipment. Purchase criteria must mirror reality; most analyses use life-cycle costing with low discount rates - most buyers use short payback periods. Distributing, installing, and marketing small, distributed solar systems is more costly than most analyses estimate. Results show that certain local conditions and uncommon purchase considerations can combine to make small, distributed solar power attractive, but lower interconnect costs (per kW), lower marketing and product distribution costs, and more favorable purchase criteria make large, centralized solar energy more attractive. Specifically, the value of dispersed solar systems to investors and utilities can be higher than $2000/kw. However, typical residential owners place a value of well under $1000 on the installed system.

Concentrating Solar Power Projects - KaXu Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL KaXu Solar One This page provides information on KaXu Solar One, a concentrating solar power (CSP) project, with data organized by background, parcipants and power plant configuration . Status Date: April 14, 2015 Project Overview Project Name: KaXu Solar One Country: South Africa Location

Utilizing Solar Power Technologies for On-Orbit Propellant Production

Science.gov (United States)

Fikes, John C.; Howell, Joe T.; Henley, Mark W.

2006-01-01

The cost of access to space beyond low Earth orbit may be reduced if vehicles can refuel in orbit. The cost of access to low Earth orbit may also be reduced by launching oxygen and hydrogen propellants in the form of water. To achieve this reduction in costs of access to low Earth orbit and beyond, a propellant depot is considered that electrolyzes water in orbit, then condenses and stores cryogenic oxygen and hydrogen. Power requirements for such a depot require Solar Power Satellite technologies. A propellant depot utilizing solar power technologies is discussed in this paper. The depot will be deployed in a 400 km circular equatorial orbit. It receives tanks of water launched into a lower orbit from Earth, converts the water to liquid hydrogen and oxygen, and stores up to 500 metric tons of cryogenic propellants. This requires a power system that is comparable to a large Solar Power Satellite capable of several 100 kW of energy. Power is supplied by a pair of solar arrays mounted perpendicular to the orbital plane, which rotates once per orbit to track the Sun. The majority of the power is used to run the electrolysis system. Thermal control is maintained by body-mounted radiators; these also provide some shielding against orbital debris. The propellant stored in the depot can support transportation from low Earth orbit to geostationary Earth orbit, the Moon, LaGrange points, Mars, etc. Emphasis is placed on the Water-Ice to Cryogen propellant production facility. A very high power system is required for cracking (electrolyzing) the water and condensing and refrigerating the resulting oxygen and hydrogen. For a propellant production rate of 500 metric tons (1,100,000 pounds) per year, an average electrical power supply of 100 s of kW is required. To make the most efficient use of space solar power, electrolysis is performed only during the portion of the orbit that the Depot is in sunlight, so roughly twice this power level is needed for operations in sunlight

Thermal power generation projects ``Large Scale Solar Heating``; EU-Thermie-Projekte ``Large Scale Solar Heating``

Energy Technology Data Exchange (ETDEWEB)

Kuebler, R.; Fisch, M.N. [Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik, Stuttgart (Germany)

1998-12-31

The aim of this project is the preparation of the ``Large-Scale Solar Heating`` programme for an Europe-wide development of subject technology. The following demonstration programme was judged well by the experts but was not immediately (1996) accepted for financial subsidies. In November 1997 the EU-commission provided 1,5 million ECU which allowed the realisation of an updated project proposal. By mid 1997 a small project was approved, that had been requested under the lead of Chalmes Industriteteknik (CIT) in Sweden and is mainly carried out for the transfer of technology. (orig.) [Deutsch] Ziel dieses Vorhabens ist die Vorbereitung eines Schwerpunktprogramms `Large Scale Solar Heating`, mit dem die Technologie europaweit weiterentwickelt werden sollte. Das daraus entwickelte Demonstrationsprogramm wurde von den Gutachtern positiv bewertet, konnte jedoch nicht auf Anhieb (1996) in die Foerderung aufgenommen werden. Im November 1997 wurden von der EU-Kommission dann kurzfristig noch 1,5 Mio ECU an Foerderung bewilligt, mit denen ein aktualisierter Projektvorschlag realisiert werden kann. Bereits Mitte 1997 wurde ein kleineres Vorhaben bewilligt, das unter Federfuehrung von Chalmers Industriteknik (CIT) in Schweden beantragt worden war und das vor allem dem Technologietransfer dient. (orig.)

Numerical analysis on the performance of solar chimney power plant system

International Nuclear Information System (INIS)

Xu Guoliang; Ming Tingzhen; Pan Yuan; Meng Fanlong; Zhou Cheng

2011-01-01

Power generating technology based on renewable energy resources will definitely become a new trend of future energy utilization. Numerical simulations on air flow, heat transfer and power output characteristics of a solar chimney power plant model with energy storage layer and turbine similar to the Spanish prototype were carried out in this paper, and mathematical model of flow and heat transfer for the solar chimney power plant system was established. The influences of solar radiation and pressure drop across the turbine on the flow and heat transfer, output power and energy loss of the solar chimney power plant system were analyzed. The numerical simulation results reveal that: when the solar radiation and the turbine efficiency are 600 W/m 2 and 80%, respectively, the output power of the system can reach 120 kW. In addition, large mass flow rate of air flowing through the chimney outlet become the main cause of energy loss in the system, and the collector canopy also results in large energy loss.

Power Converters Maximize Outputs Of Solar Cell Strings

Science.gov (United States)

Frederick, Martin E.; Jermakian, Joel B.

1993-01-01

Microprocessor-controlled dc-to-dc power converters devised to maximize power transferred from solar photovoltaic strings to storage batteries and other electrical loads. Converters help in utilizing large solar photovoltaic arrays most effectively with respect to cost, size, and weight. Main points of invention are: single controller used to control and optimize any number of "dumb" tracker units and strings independently; power maximized out of converters; and controller in system is microprocessor.

Solar power from space: the worldwide grid of the future

International Nuclear Information System (INIS)

Anon.

2000-01-01

Recent interest in the feasibility and prospects for generating large amounts of electricity from space-based solar power systems is reviewed. The interest is generated by reports which suggest that sun-surfacing solar arrays in stationary earth orbit at an altitude 22,300 miles would not only be unaffected by the Earth's day-night cycle, cloud cover and atmospheric dust, but would also receive some eight times as much sunlight as solar collectors at the Earth's surface. The prediction is that relevant technology will be perfected to the point where by the middle of the 21. century a large share of the world's demand for electricity will be met by a series of very large space-based solar photovoltaic arrays. Several billion watts of power could be beamed to the Earth at microwave radio frequencies for collection by wide area rectifying ground antennas for conversion to electricity via transmitters connected to the photovoltaic arrays. A chronological account of development of this concept of beaming solar power from space shows that the idea has been around since the 1880s, gaining more and more credibility with each advance in space science . The moon, too, has been suggested as an ideal site for developing large-scale solar power systems that beam microwave energy to Earth. The lunar soil could supply silicon to build solar arrays, and metals such as iron and aluminum, for support structures and electric wiring. NASA is actively pursuing this line of inquiry, especially since all the problems involved with solar energy generation on earth, are absent on the moon.While a breakthrough is not imminent, the significant progress achieved to date in demonstrating the feasibility of wireless power transmission from space provides good reason for continuing to pursue this line of investigation

Large-scale solar purchasing

International Nuclear Information System (INIS)

1999-01-01

The principal objective of the project was to participate in the definition of a new IEA task concerning solar procurement (''the Task'') and to assess whether involvement in the task would be in the interest of the UK active solar heating industry. The project also aimed to assess the importance of large scale solar purchasing to UK active solar heating market development and to evaluate the level of interest in large scale solar purchasing amongst potential large scale purchasers (in particular housing associations and housing developers). A further aim of the project was to consider means of stimulating large scale active solar heating purchasing activity within the UK. (author)

Thermal energy storage for CSP (Concentrating Solar Power)

Science.gov (United States)

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

2017-07-01

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

Thermal energy storage for CSP (Concentrating Solar Power

Directory of Open Access Journals (Sweden)

Py Xavier

2017-01-01

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

Inclined solar chimney for power production

International Nuclear Information System (INIS)

Panse, S.V.; Jadhav, A.S.; Gudekar, A.S.; Joshi, J.B.

2011-01-01

Highlights: → Solar energy harnessing using inclined face of high mountains as solar chimney. → Solar chimneys with structural stability, ease of construction and lower cost. → Mathematical model developed, using complete (mechanical and thermal) energy balance. → Can harness wind power also, as wind velocities at mountain top add to power output. → Air temperature and velocity increase, as air rises in inclined chimney. - Abstract: The present concept of solar chimney is a tall vertical chimney constructed at the center of a large area, which is the collector. This creates questions about stability and economic viability of the chimney and also demands elaborate engineering techniques for constructing a tall chimney. We suggest geometry of 'Inclined Solar Chimney' (ISC), which is constructed along the face of a high rising mountain, on which maximum solar insolation is incident throughout the year. The chimney and the collector get merged here. This makes the structure stable, cost effective and easy for construction. A mathematical model has been developed considering the total energy balance. It predicts the temperature and velocity and kinetic power of the emerging air draft for some chosen values of other parameters. The model also shows the proportion in which absorbed solar energy is divided into different forms, and hence predicts the dependence of kinetic of emerging air draft upon dimensions of the chimney and properties of materials used. Further, it is shown that external winds enhance the kinetic power of the emerging air. Thus ISC can also harness the wind energy, available at the top of the mountain.

Variability of Power from Large-Scale Solar Photovoltaic Scenarios in the State of Gujarat: Preprint

Energy Technology Data Exchange (ETDEWEB)

Parsons, B.; Hummon, M.; Cochran, J.; Stoltenberg, B.; Batra, P.; Mehta, B.; Patel, D.

2014-04-01

India has ambitious goals for high utilization of variable renewable power from wind and solar, and deployment has been proceeding at a rapid pace. The western state of Gujarat currently has the largest amount of solar generation of any Indian state, with over 855 Megawatts direct current (MWDC). Combined with over 3,240 MW of wind, variable generation renewables comprise nearly 18% of the electric-generating capacity in the state. A new historic 10-kilometer (km) gridded solar radiation data set capturing hourly insolation values for 2002-2011 is available for India. We apply an established method for downscaling hourly irradiance data to one-minute irradiance data at potential PV power production locations for one year, 2006. The objective of this report is to characterize the intra-hour variability of existing and planned photovoltaic solar power generation in the state of Gujarat (a total of 1.9 gigawatts direct current (GWDC)), and of five possible expansion scenarios of solar generation that reflect a range of geographic diversity (each scenario totals 500-1,000 MW of additional solar capacity). The report statistically analyzes one year's worth of power variability data, applied to both the baseline and expansion scenarios, to evaluate diurnal and seasonal power fluctuations, different timescales of variability (e.g., from one to 15 minutes), the magnitude of variability (both total megawatts and relative to installed solar capacity), and the extent to which the variability can be anticipated in advance. The paper also examines how Gujarat Energy Transmission Corporation (GETCO) and the Gujarat State Load Dispatch Centre (SLDC) could make use of the solar variability profiles in grid operations and planning.

The Future of Solar Power in the United Kingdom

Directory of Open Access Journals (Sweden)

Gerard Reid

2015-07-01

Full Text Available We used detailed industry data to analyse the impacts of expected further cost reductions on the competitiveness of solar power in Britain, and assess whether the solar market can survive without support in the near future. We investigated three solar power markets: large-scale, ground-mounted “solar farms” (defined in our analysis as larger than a 5000 kilowatt system; commercial roof-top (250 kW; and residential rooftop (3 kW. We found that all three would be economic without support in the next decade. Such an outcome assumes progressively falling support under a stable policy regime. We found that unsubsidised residential solar power may be cheaper with battery storage within the next five to 10 years. Unsupported domestic solar battery packs achieve payback periods of less than 10 years by 2025. That could create an inflexion point driving adoption of domestic solar systems. The variability of solar power will involve some grid integration costs at higher penetration levels, such as more frequent power market scheduling; more interconnector capacity; storage; and backup power. These costs and responses could be weighed against non-market benefits including the potential for grid balancing; lower carbon and particulate emissions; and energy security.

Solar power role in the future power engineering

International Nuclear Information System (INIS)

Strebkov, D.S.

2006-01-01

One studied the most essential factors, materials and processes governing the role of the solar power in the future power generation. Paper describes new principles to convert solar energy, to produce solar silicon and solar elements, to encapsulate solar modules, to make use of stationary solar concentrators [ru

Lightweight Solar Power for Small Satellites

Science.gov (United States)

Nabors, Sammy A.

2015-01-01

The innovation targets small satellites or CubeSats for which conventional deployable arrays are not feasible due to their size, weight and complexity. This novel solar cell array includes a thin and flexible photovoltaic cell applied to an inflatable structure to create a high surface area array for collecting solar energy in a lightweight, simple and deployable structure. The inflatable array, with its high functional surface area, eliminates the need and the mechanisms required to point the system toward the sun. The power density achievable in these small arrays is similar to that of conventional high-power deployable/pointable arrays used on large satellites or space vehicles. Although inflatable solar arrays have been previously considered by others, the arrays involved the use of traditional rigid solar cells. Researchers are currently working with thin film photovoltaics from various suppliers so that the NASA innovation is not limited to any particular solar cell technology. NASA has built prototypes and tested functionality before and after inflation. As shown in the current-voltage currents below, deployment does not damage the cell performance.

Influence of large-scale deployment of concentrated solar power on North African countries: Socio-economic aspects (Conference Paper)

OpenAIRE

Komendantova, N.; Patt, A.

2010-01-01

To prevent catastrophic results of climate change, the stabilization of atmospheric concentrations of CO2 below 450 or even 350 parts per million is necessary. The large-scale electricity generation from renewable energy sources is one of possible options to satisfy the world's growing energy demand and to reduce green house gas emissions from electricity generation. Several studies show technical viability of large-scale deployment of concentrated solar power in North African countries and i...

Space Solar Power Technology Demonstration for Lunar Polar Applications: Laser-Photovoltaic Wireless Power Transmission

Science.gov (United States)

Henley, M. W.; Fikes, J. C.; Howell, J.; Mankins, J. C.; Howell, Joe T. (Technical Monitor)

2002-01-01

Space Solar Power technology offers unique benefits for near-term NASA space science missions, which can mature this technology for other future applications. "Laser-Photo-Voltaic Wireless Power Transmission" (Laser-PV WPT) is a technology that uses a laser to beam power to a photovoltaic receiver, which converts the laser's light into electricity. Future Laser-PV WPT systems may beam power from Earth to satellites or large Space Solar Power satellites may beam power to Earth, perhaps supplementing terrestrial solar photo-voltaic receivers. In a near-term scientific mission to the moon, Laser-PV WPT can enable robotic operations in permanently shadowed lunar polar craters, which may contain ice. Ground-based technology demonstrations are proceeding, to mature the technology for this initial application, in the moon's polar regions.

Solar photovoltaic projects in the mainstream power market

CERN Document Server

Wolfe, Philip

2012-01-01

Develop large-scale solar photovoltaic projects with this book, to feed power into a grid. Contains case studies of the Waldpolenz Energy Park, Germany, Lopburi Solar Plant in Thailand and what will be the world's largest PV plant, the Topaz Solar Farm in California. Also included are interviews from leading figures in the PV industry.Contents cover:planning and structuring projectssiting, planning and connection issuesbuilding and operating projectstechnology basicseconomies of PVhistory and business of PVfinancing and regulationtechnical aspects of system design.Supported by figures and photographs, this is for anyone wanting to master the commercial, professional, financial, engineering or political aspects of developing mega-watt solar PV projects in a mainstream power market.

Solar power satellite life-cycle energy recovery consideration

Science.gov (United States)

Weingartner, S.; Blumenberg, J.

The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead on monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on earth (rectenna) requires about 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production installation and operation, is about two years.

Solar power satellite—Life-cycle energy recovery considerations

Science.gov (United States)

Weingartner, S.; Blumenberg, J.

1995-05-01

The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for a cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead of monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power plant components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on Earth (rectenna) requires in the order of 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production, installation and operation, is in the order of two years.

Candidate solar cell materials for photovoltaic conversion in a solar power satellite /SPS/

Science.gov (United States)

Glaser, P. E.; Almgren, D. W.

1978-01-01

In recognition of the obstacles to solar-generated baseload power on earth, proposals have been made to locate solar power satellites in geosynchronous earth orbit (GEO), where solar energy would be available 24 hours a day during most of the time of the year. In an SPS, the electricity produced by solar energy conversion will be fed to microwave generators forming part of a planar phase-array transmitting antenna. The antenna is designed to precisely direct a microwave beam of very low intensity to one or more receiving antennas at desired locations on earth. At the receiving antenna, the microwave energy will be safely and efficiently reconverted to electricity and then be transmitted to consumers. An SPS system will include a number of satellites in GEO. Attention is given to the photovoltaic option for solar energy conversion in GEO, solar cell requirements, the availability of materials, the implication of large production volumes, requirements for high-volume manufacture of solar cell arrays, and the effects of concentration ratio on solar cell array area.

Heat-rejection design for large concentrating solar arrays

Science.gov (United States)

French, E. P.

1980-01-01

This paper considers the effect of heat rejection devices (radiators) on the performance and cost of large concentrating solar arrays for space application. Overall array characteristics are derived from the weight, cost, and performance of four major components; namely primary structure, optics/secondary structure, radiator, and solar panel. An ideal concentrator analysis is used to establish general cost and performance trends independent of specific array design. Both passive and heat-pipe radiation are evaluated, with an incremental cost-of-power approach used in the evaluation. Passive radiators are found to be more cost effective with silicon than with gallium arsenide (GaAs) arrays. Representative concentrating arrays have been evaluated for both near-term and advanced solar cell technology. Minimum cost of power is achieved at geometric concentration ratios in the range 2 to 6.

New Earth-abundant Materials for Large-scale Solar Fuels Generation.

Science.gov (United States)

Prabhakar, Rajiv Ramanujam; Cui, Wei; Tilley, S David

2018-05-30

The solar resource is immense, but the power density of light striking the Earth's surface is relatively dilute, necessitating large area solar conversion devices in order to harvest substantial amounts of power for renewable energy applications. In addition, energy storage is a key challenge for intermittent renewable resources such as solar and wind, which adds significant cost to these energies. As the majority of humanity's present-day energy consumption is based on fuels, an ideal solution is to generate renewable fuels from abundant resources such as sunlight and water. In this account, we detail our recent work towards generating highly efficient and stable Earth-abundant semiconducting materials for solar water splitting to generate renewable hydrogen fuel.

Roll-coating fabrication of flexible large area small molecule solar cells with power conversion efficiency exceeding 1%

DEFF Research Database (Denmark)

Liu, Wenqing; Liu, Shiyong; Zawacka, Natalia Klaudia

2014-01-01

All solution-processed flexible large area small molecule bulk heterojunction solar cells were fabricated via roll-coating technology. Our devices were produced from slot-die coating on a lab-scale mini roll-coater under ambient conditions without the use of spin-coating or vacuum evaporation.......01%, combined with an open circuit voltage of 0.73 V, a short-circuit current density of 3.13 mA cm (2) and a fill factor of 44% were obtained for the device with SM1, which was the first example reported for efficient roll-coating fabrication of flexible large area small molecule solar cells with PCE exceeding...... methods. Four diketopyrrolopyrrole based small molecules (SMs 1-4) were utilized as electron donors with (6,6)phenyl- C61-butyric acid methyl ester as an acceptor and their photovoltaic performances based on roll-coated devices were investigated. The best power conversion efficiency (PCE) of 1...

Solar power in Finland

International Nuclear Information System (INIS)

Vesa, A.M.

2004-01-01

Solar cells, or photovoltaic units, have provided a useful supply of energy for low-power, non-gridconnected applications in Finland for some years. Applications have included navigational buoys, base stations for mobile phone networks, and appliances in holiday homes. Solar-powered systems have also been used in connection with grid power for over a decade, in Finland and elsewhere, and have proved generally successful - and solar energy is emerging as an increasingly interesting alternative for distributed electricity generation

Solar powered dugout aeration

International Nuclear Information System (INIS)

Murrell, S.

2001-10-01

Pasture dugouts are a significant source of water for livestock on the Canadian Prairies and as such, must maintain the best water quality possible. Aeration improves the water quality and is part of a good management plan to reduce overall water treatment costs. Although dugouts can be aerated naturally through wind and wave action and photosynthesis, this generally aerates only the top portion of the dugout. Artificial aeration by air injection into the lowest point of the dugout ensures that the water is oxygenated throughout the entire dugout. Solar aeration can be used in remote areas where grid power is not practical. With solar powered aeration systems, solar panels are used to generate the electrical power needed to run the compressor while storing excess energy in batteries. A solar aeration system includes solar panels, deep cycle batteries to store excess power, a control board with a regulator, a compressor, a weighed feeder hose, and an air diffuser. This publication presented the design of a solar aeration system and its cost. 1 tab., 3 figs

Air emissions due to wind and solar power.

Science.gov (United States)

Katzenstein, Warren; Apt, Jay

2009-01-15

Renewables portfolio standards (RPS) encourage large-scale deployment of wind and solar electric power. Their power output varies rapidly, even when several sites are added together. In many locations, natural gas generators are the lowest cost resource available to compensate for this variability, and must ramp up and down quickly to keep the grid stable, affecting their emissions of NOx and CO2. We model a wind or solar photovoltaic plus gas system using measured 1-min time-resolved emissions and heat rate data from two types of natural gas generators, and power data from four wind plants and one solar plant. Over a wide range of renewable penetration, we find CO2 emissions achieve approximately 80% of the emissions reductions expected if the power fluctuations caused no additional emissions. Using steam injection, gas generators achieve only 30-50% of expected NOx emissions reductions, and with dry control NOx emissions increase substantially. We quantify the interaction between state RPSs and NOx constraints, finding that states with substantial RPSs could see significant upward pressure on NOx permit prices, if the gas turbines we modeled are representative of the plants used to mitigate wind and solar power variability.

Large-scale solar heat

Energy Technology Data Exchange (ETDEWEB)

Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics

1998-12-31

In this project a large domestic solar heating system was built and a solar district heating system was modelled and simulated. Objectives were to improve the performance and reduce costs of a large-scale solar heating system. As a result of the project the benefit/cost ratio can be increased by 40 % through dimensioning and optimising the system at the designing stage. (orig.)

Convex relaxation of Optimal Power Flow in Distribution Feeders with embedded solar power

DEFF Research Database (Denmark)

Hermann, Alexander Niels August; Wu, Qiuwei; Huang, Shaojun

2016-01-01

There is an increasing interest in using Distributed Energy Resources (DER) directly coupled to end user distribution feeders. This poses an array of challenges because most of today’s distribution feeders are designed for unidirectional power flow. Therefore when installing DERs such as solar...... panels with uncontrolled inverters, the upper limit of installable capacity is quickly reached in many of today’s distribution feeders. This problem can often be mitigated by optimally controlling the voltage angles of inverters. However, the optimal power flow problem in its standard form is a large...... scale non-convex optimization problem, and thus can’t be solved precisely and also is computationally heavy and intractable for large systems. This paper examines the use of a convex relaxation using Semi-definite programming to optimally control solar power inverters in a distribution grid in order...

Improved high temperature solar absorbers for use in Concentrating Solar Power central receiver applications.

Energy Technology Data Exchange (ETDEWEB)

Stechel, Ellen Beth; Ambrosini, Andrea; Hall, Aaron Christopher; Lambert, Timothy L.; Staiger, Chad Lynn; Bencomo, Marlene

2010-09-01

Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures >600 C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.05) in the IR region, be stable in air, and be low-cost and readily manufacturable. We propose to utilize solution-based synthesis techniques to prepare intrinsic absorbers for use in central receiver applications.

Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays

Science.gov (United States)

Glaser, P. E.

1974-01-01

The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

A 100 kW-Class Technology Demonstrator for Space Solar Power

Science.gov (United States)

Carrington, Connie; Howell, Joe; Day, Greg

2004-01-01

A first step in the development of solar power from space is the flight demonstration of critical technologies. These fundamental technologies include efficient solar power collection and generation, power management and distribution, and thermal management. In addition, the integration and utilization of these technologies into a viable satellite bus could provide an energy-rich platform for a portfolio of payload experiments such as wireless power transmission (WPT). This paper presents the preliminary design of a concept for a 100 kW-class fiee-flying platform suitable for flight demonstration of technology experiments. Recent space solar power (SSP) studies by NASA have taken a stepping stones approach that lead to the gigawatt systems necessary to cost-effectively deliver power from space. These steps start with a 100 kW-class satellite, leading to a 500 kW and then a 1 MW-class platform. Later steps develop a 100 M W bus that could eventually lead to a 1-2 GW pilot plant for SSP. Our studies have shown that a modular approach is cost effective. Modular designs include individual laser-power-beaming satellites that fly in constellations or that are autonomously assembled into larger structures at geosynchronous orbit (GEO). Microwave power-beamed approaches are also modularized into large numbers of identical units of solar arrays, power converters, or supporting structures for arrays and microwave transmitting antennas. A cost-effective approach to launching these modular units is to use existing Earth-to-orbit (ETO) launch systems, in which the modules are dropped into low Earth orbit (LEO) and then the modules perform their own orbit transfer to GEO using expendable solar arrays to power solar electric thrusters. At GEO, the modules either rendezvous and are assembled robotically into larger platforms, or are deployed into constellations of identical laser power-beaming satellites. Since solar electric propulsion by the modules is cost-effective for both

Solar microclimatology. [tables (data) on insolation for application to solar energy conversion by electric power plants

Science.gov (United States)

Mckenney, D. B.; Beauchamp, W. T.

1975-01-01

It has become apparent in recent years that solar energy can be used for electric power production by several methods. Because of the diffuse nature of the solar insolation, the area involved in any central power plant design can encompass several square miles. A detailed design of these large area collection systems will require precise knowledge of the local solar insolation. Detailed information will also be needed concerning the temporal nature of the insolation and the local spatial distribution. Therefore, insolation data was collected and analyzed for a network of sensors distributed over an area of several square kilometers in Arizona. The analyses of this data yielded probability distributions of cloud size, velocity, and direction of motion which were compared with data obtained from the National Weather Service. Microclimatological analyses were also performed for suitable modeling parameters pertinent to large scale electric power plant design. Instrumentation used to collect the data is described.

Concentrating Solar Power: Best Practices Handbook for the Collection and Use of Solar Resource Data (CSP)

Energy Technology Data Exchange (ETDEWEB)

Stoffel, T.; Renne, D.; Myers, D.; Wilcox, S.; Sengupta, M.; George, R.; Turchi, C.

2010-09-01

As the world looks for low-carbon sources of energy, solar power stands out as the most abundant energy resource. Harnessing this energy is the challenge for this century. Photovoltaics and concentrating solar power (CSP) are two primary forms of electricity generation using sunlight. These use different technologies, collect different fractions of the solar resource, and have different siting and production capabilities. Although PV systems are most often deployed as distributed generation sources, CSP systems favor large, centrally located systems. Accordingly, large CSP systems require a substantial investment, sometimes exceeding $1 billion in construction costs. Before such a project is undertaken, the best possible information about the quality and reliability of the fuel source must be made available. That is, project developers need to have reliable data about the solar resource available at specific locations to predict the daily and annual performance of a proposed CSP plant. Without these data, no financial analysis is possible. This handbook presents detailed information about solar resource data and the resulting data products needed for each stage of the project.

Contribution of Strong Discontinuities to the Power Spectrum of the Solar Wind

International Nuclear Information System (INIS)

Borovsky, Joseph E.

2010-01-01

Eight and a half years of magnetic field measurements (2 22 samples) from the ACE spacecraft in the solar wind at 1 A.U. are analyzed. Strong (large-rotation-angle) discontinuities in the solar wind are collected and measured. An artificial time series is created that preserves the timing and amplitudes of the discontinuities. The power spectral density of the discontinuity series is calculated and compared with the power spectral density of the solar-wind magnetic field. The strong discontinuities produce a power-law spectrum in the ''inertial subrange'' with a spectral index near the Kolmogorov -5/3 index. The discontinuity spectrum contains about half of the power of the full solar-wind magnetic field over this ''inertial subrange.'' Warnings are issued about the significant contribution of discontinuities to the spectrum of the solar wind, complicating interpretation of spectral power and spectral indices.

Financing Solar Thermal Power Plants

International Nuclear Information System (INIS)

Price, Henry W.; Kistner, Rainer

1999-01-01

The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been build following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply stated, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects from the financier's perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies

Financing solar thermal power plants

International Nuclear Information System (INIS)

Kistner, R.; Price, H.

1999-01-01

The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been built following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply states, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects form the financier's perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies

Financing Solar Thermal Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kistner, Rainer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Price, Henry W. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

1999-04-14

The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been build following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply stated, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects from the financier’s perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies.

Evaluating the enablers in solar power developments in the current scenario using fuzzy DEMATEL

DEFF Research Database (Denmark)

Luthra, Sunil; Govindan, Kannan; Kharb, Ravinder K.

2016-01-01

Determining solar power initiatives and developments for a country as large as India is difficult due to the involvement of different enablers. The decisions of these enablers will influence the formulation of strategies to encourage solar power development in India. The present research work...... critically analyzes Indian solar power developments to recognize and to evaluate key enablers that will encourage greater usage in Indias current scenario. A literature review that explores the Indian solar power sector is included, with a focus on need potential, and an examination of the key enablers....... This work identifies sixteen solar power enablers based on relevant literature and experts inputs. To evaluate and to categorize the recognized solar power development key enablers, a fuzzy Decision Making Trial and Evaluation Laboratory (DEMATEL) based methodology is utilized. The fuzzy DEMATEL approach...

Solar Power Beaming: From Space to Earth

Energy Technology Data Exchange (ETDEWEB)

Rubenchik, A M; Parker, J M; Beach, R J; Yamamoto, R M

2009-04-14

Harvesting solar energy in space and power beaming the collected energy to a receiver station on Earth is a very attractive way to help solve mankind's current energy and environmental problems. However, the colossal and expensive 'first step' required in achieving this goal has to-date stifled its initiation. In this paper, we will demonstrate that recent advance advances in laser and optical technology now make it possible to deploy a space-based system capable of delivering 1 MW of energy to a terrestrial receiver station, via a single unmanned commercial launch into Low Earth Orbit (LEO). Figure 1 depicts the overall concept of our solar power beaming system, showing a large solar collector in space, beaming a coherent laser beam to a receiving station on Earth. We will describe all major subsystems and provide technical and economic discussion to support our conclusions.

Maximum Power from a Solar Panel

Directory of Open Access Journals (Sweden)

Michael Miller

2010-01-01

Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

The potential of concentrating solar power in South Africa

Energy Technology Data Exchange (ETDEWEB)

Fluri, Thomas P. [Department of Mechanical and Mechatronic Engineering, University of Stellenbosch, Private Bag X1, Matieland 7602 (South Africa)

2009-12-15

In this paper all provinces of South Africa with a good potential for the implementation of large-scale concentrating solar power plants are identified using geographic information systems. The areas are assumed suitable if they get sufficient sunshine, are close enough to transmission lines, are flat enough, their respective vegetation is not under threat and they have a suitable land use profile. Various maps are created showing the solar resource, the slope, areas with 'least threatened' vegetation, proximity to transmission lines and areas suitable for the installation of large concentrating solar power plants. Assuming the installation of parabolic trough plants, it is found that the identified suitable areas could accommodate plants with a nominal capacity of 510.3 GW in the Northern Cape, 25.3 GW in the Free State, 10.5 GW in the Western Cape and 1.6 GW in the Eastern Cape, which gives a total potential nominal capacity of 547.6 GW for the whole country. (author)

Comparison of candidate solar array maximum power utilization approaches. [for spacecraft propulsion

Science.gov (United States)

Costogue, E. N.; Lindena, S.

1976-01-01

A study was made of five potential approaches that can be utilized to detect the maximum power point of a solar array while sustaining operations at or near maximum power and without endangering stability or causing array voltage collapse. The approaches studied included: (1) dynamic impedance comparator, (2) reference array measurement, (3) onset of solar array voltage collapse detection, (4) parallel tracker, and (5) direct measurement. The study analyzed the feasibility and adaptability of these approaches to a future solar electric propulsion (SEP) mission, and, specifically, to a comet rendezvous mission. Such missions presented the most challenging requirements to a spacecraft power subsystem in terms of power management over large solar intensity ranges of 1.0 to 3.5 AU. The dynamic impedance approach was found to have the highest figure of merit, and the reference array approach followed closely behind. The results are applicable to terrestrial solar power systems as well as to other than SEP space missions.

A Comparison of a Solar Power Satellite Concept to a Concentrating Solar Power System

Science.gov (United States)

Smitherman, David V.

2013-01-01

A comparison is made of a solar power satellite (SPS) concept in geostationary Earth orbit to a concentrating solar power (CSP) system on the ground to analyze overall efficiencies of each infrastructure from solar radiance at 1 AU to conversion and transmission of electrical energy into the power grid on the Earth's surface. Each system is sized for a 1-gigawatt output to the power grid and then further analyzed to determine primary collector infrastructure areas. Findings indicate that even though the SPS concept has a higher end-to-end efficiency, the combined space and ground collector infrastructure is still about the same size as a comparable CSP system on the ground.

The power of PV: one US company shows the potential of solar energy

International Nuclear Information System (INIS)

Wood, L.

2005-01-01

A California-based company, PowerLight, has grown from a one-man shop in 1991 to a company with 100 employees, an annual turnover of $100 million and an impressive client list. The company is one of the USA's fastest growing companies and a leader in large-scale, grid-connected solar systems. Its patented PowerGuard offers a lightweight solar rooftop assembly, while its PowerTracker product is a ground-mounted PV system. Details of some of the company's large projects are given and its plans for new markets highlighted

Solar-powered Gossamer Penguin in flight

Science.gov (United States)

1979-01-01

Gossamer Penguin in flight above Rogers Dry Lakebed at Edwards, California, showing the solar panel perpendicular to the wing and facing the sun. Background The first flight of a solar-powered aircraft took place on November 4, 1974, when the remotely controlled Sunrise II, designed by Robert J. Boucher of AstroFlight, Inc., flew following a launch from a catapult. Following this event, AeroVironment, Inc. (founded in 1971 by the ultra-light airplane innovator--Dr. Paul MacCready) took on a more ambitious project to design a human-piloted, solar-powered aircraft. The firm initially took the human-powered Gossamer Albatross II and scaled it down to three-quarters of its previous size for solar-powered flight with a human pilot controlling it. This was more easily done because in early 1980 the Gossamer Albatross had participated in a flight research program at NASA Dryden in a program conducted jointly by the Langley and Dryden research centers. Some of the flights were conducted using a small electric motor for power. Gossamer Penguin The scaled-down aircraft was designated the Gossamer Penguin. It had a 71-foot wingspan compared with the 96-foot span of the Gossamer Albatross. Weighing only 68 pounds without a pilot, it had a low power requirement and thus was an excellent test bed for solar power. AstroFlight, Inc., of Venice, Calif., provided the power plant for the Gossamer Penguin, an Astro-40 electric motor. Robert Boucher, designer of the Sunrise II, served as a key consultant for both this aircraft and the Solar Challenger. The power source for the initial flights of the Gossamer Penguin consisted of 28 nickel-cadmium batteries, replaced for the solar-powered flights by a panel of 3,920 solar cells capable of producing 541 Watts of power. The battery-powered flights took place at Shafter Airport near Bakersfield, Calif. Dr. Paul MacCready's son Marshall, who was 13 years old and weighed roughly 80 pounds, served as the initial pilot for these flights to

MEASUREMENT OF LARGE-SCALE SOLAR POWER PLANT BY USING IMAGES ACQUIRED BY NON-METRIC DIGITAL CAMERA ON BOARD UAV

Directory of Open Access Journals (Sweden)

R. Matsuoka

2012-07-01

Full Text Available This paper reports an experiment conducted in order to investigate the feasibility of the deformation measurement of a large-scale solar power plant on reclaimed land by using images acquired by a non-metric digital camera on board a micro unmanned aerial vehicle (UAV. It is required that a root mean squares of errors (RMSE in height measurement should be less than 26 mm that is 1/3 of the critical limit of deformation of 78 mm off the plane of a solar panel. Images utilized in the experiment have been obtained by an Olympus PEN E-P2 digital camera on board a Microdrones md4-1000 quadrocopter. The planned forward and side overlap ratios of vertical image acquisition have been 60 % and 60 % respectively. The planned flying height of the UAV has been 20 m above the ground level and the ground resolution of an image is approximately 5.0 mm by 5.0 mm. 8 control points around the experiment area are utilized for orientation. Measurement results are evaluated by the space coordinates of 220 check points which are corner points of 55 solar panels selected from 1768 solar panels in the experiment area. Two teams engage in the experiment. One carries out orientation and measurement by using 171 images following the procedure of conventional aerial photogrammetry, and the other executes those by using 126 images in the manner of close range photogrammetry. The former fails to satisfy the required accuracy, while the RMSE in height measurement by the latter is 8.7 mm that satisfies the required accuracy. From the experiment results, we conclude that the deformation measurement of a large-scale solar power plant on reclaimed land by using images acquired by a nonmetric digital camera on board a micro UAV would be feasible if points utilized in orientation and measurement have a sufficient number of bundles in good geometry and self-calibration in orientation is carried out.

Hybrid PV/diesel solar power system design using multi-level factor analysis optimization

Science.gov (United States)

Drake, Joshua P.

Solar power systems represent a large area of interest across a spectrum of organizations at a global level. It was determined that a clear understanding of current state of the art software and design methods, as well as optimization methods, could be used to improve the design methodology. Solar power design literature was researched for an in depth understanding of solar power system design methods and algorithms. Multiple software packages for the design and optimization of solar power systems were analyzed for a critical understanding of their design workflow. In addition, several methods of optimization were studied, including brute force, Pareto analysis, Monte Carlo, linear and nonlinear programming, and multi-way factor analysis. Factor analysis was selected as the most efficient optimization method for engineering design as it applied to solar power system design. The solar power design algorithms, software work flow analysis, and factor analysis optimization were combined to develop a solar power system design optimization software package called FireDrake. This software was used for the design of multiple solar power systems in conjunction with an energy audit case study performed in seven Tibetan refugee camps located in Mainpat, India. A report of solar system designs for the camps, as well as a proposed schedule for future installations was generated. It was determined that there were several improvements that could be made to the state of the art in modern solar power system design, though the complexity of current applications is significant.

Short-Term Solar Collector Power Forecasting

DEFF Research Database (Denmark)

Bacher, Peder; Madsen, Henrik; Perers, Bengt

2011-01-01

This paper describes a new approach to online forecasting of power output from solar thermal collectors. The method is suited for online forecasting in many applications and in this paper it is applied to predict hourly values of power from a standard single glazed large area flat plate collector...... enabling tracking of changes in the system and in the surrounding conditions, such as decreasing performance due to wear and dirt, and seasonal changes such as leaves on trees. This furthermore facilitates remote monitoring and check of the system....

Solar and nuclear power are partners

International Nuclear Information System (INIS)

Rossin, A.D.

1985-01-01

This chapter attempts to refute the claim made by solar energy proponents that the continued reliance on electric grids with coal-fired and nuclear plants hinders the development of solar energy sources. It is proposed that solar and nuclear power do not compete with one another, no energy source can do the job alone, and the future of solar energy is brightest only if nuclear power succeeds. Since electric utilities have to generate almost twice as much energy during the day than at night, solar energy could be used to decrease the amount of electric power the nuclear power plants must supply at peak periods. It is argued that the key to solving future energy demands is diversity in the forms of energy supply

Motivation for the European Union to support large solar power plants

International Nuclear Information System (INIS)

Brakmann, Georg

1997-01-01

An invited article discusses the opportunities for large, electricity generating solar thermal plants in the European Union. It is claimed that although it is currently not competitive with current oil prices, it is cheaper than photovoltaics. Topics covered include CO 2 emission reduction, likely subsidies required, job creation and taxation. (UK)

Decentralised Solar Power at Homes

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Decentralised Solar Power at Homes. Solar PV gives DC Power. But load is AC; Needs a DC-AC convertor. Now if we add a battery. Battery stores only DC. Require a AC-DC convertor for charging; Require a DC-AC convertor during discharging. For low power, each ...

Stochastic Short-term High-resolution Prediction of Solar Irradiance and Photovoltaic Power Output

Energy Technology Data Exchange (ETDEWEB)

Melin, Alexander M. [ORNL; Olama, Mohammed M. [ORNL; Dong, Jin [ORNL; Djouadi, Seddik M. [ORNL; Zhang, Yichen [University of Tennessee, Knoxville (UTK), Department of Electrical Engineering and Computer Science

2017-09-01

The increased penetration of solar photovoltaic (PV) energy sources into electric grids has increased the need for accurate modeling and prediction of solar irradiance and power production. Existing modeling and prediction techniques focus on long-term low-resolution prediction over minutes to years. This paper examines the stochastic modeling and short-term high-resolution prediction of solar irradiance and PV power output. We propose a stochastic state-space model to characterize the behaviors of solar irradiance and PV power output. This prediction model is suitable for the development of optimal power controllers for PV sources. A filter-based expectation-maximization and Kalman filtering mechanism is employed to estimate the parameters and states in the state-space model. The mechanism results in a finite dimensional filter which only uses the first and second order statistics. The structure of the scheme contributes to a direct prediction of the solar irradiance and PV power output without any linearization process or simplifying assumptions of the signal’s model. This enables the system to accurately predict small as well as large fluctuations of the solar signals. The mechanism is recursive allowing the solar irradiance and PV power to be predicted online from measurements. The mechanism is tested using solar irradiance and PV power measurement data collected locally in our lab.

Microgrid Control Strategy Utlizing Thermal Energy Storage With Renewable Solar And Wind Power Generation

Science.gov (United States)

2016-06-01

iii Approved for public release; distribution is unlimited MICROGRID CONTROL STRATEGY UTLIZING THERMAL ENERGY STORAGE WITH RENEWABLE SOLAR AND WIND... control tracks increasing power generation in the morning. The batteries require a large amount of electrical power to charge every morning, as charge ...is 37 lost throughout the night. This causes the solar panels to output their maximum power generation. The MPPT control records when power

Space Solar Power: Satellite Concepts

Science.gov (United States)

Little, Frank E.

1999-01-01

Space Solar Power (SSP) applies broadly to the use of solar power for space related applications. The thrust of the NASA SSP initiative is to develop concepts and demonstrate technology for applying space solar power to NASA missions. Providing power from satellites in space via wireless transmission to a receiving station either on earth, another celestial body or a second satellite is one goal of the SSP initiative. The sandwich design is a satellite design in which the microwave transmitting array is the front face of a thin disk and the back of the disk is populated with solar cells, with the microwave electronics in between. The transmitter remains aimed at the earth in geostationary orbit while a system of mirrors directs sunlight to the photovoltaic cells, regardless of the satellite's orientation to the sun. The primary advantage of the sandwich design is it eliminates the need for a massive and complex electric power management and distribution system for the satellite. However, it requires a complex system for focusing sunlight onto the photovoltaic cells. In addition, positioning the photovoltaic array directly behind the transmitting array power conversion electronics will create a thermal management challenge. This project focused on developing designs and finding emerging technology to meet the challenges of solar tracking, a concentrating mirror system including materials and coatings, improved photovoltaic materials and thermal management.

Solar Powered Remediation and pH Control

Science.gov (United States)

2017-04-13

zone. The PRT system was completely powered via an off-the-grid solar power system . The system consisted of four 85 watt photovoltaic solar panels...polarity of the proton reduction system can be periodically alternated (i.e., the anode becomes a cathode) to increase the size of the treatment area, to...PRT System The PRT system was completely powered via an off-the-grid solar power system . The system consisted of four 85 watt photovoltaic solar

Deployable Propulsion and Power Systems for Solar System Exploration

Science.gov (United States)

Johnson, Les; Carr, John

2017-01-01

NASA is developing thin-film based, deployable propulsion, power and communication systems for small spacecraft that could provide a revolutionary new capability allowing small spacecraft exploration of the solar system. The Near Earth Asteroid (NEA) Scout reconnaissance mission will demonstrate solar sail propulsion on a 6U CubeSat interplanetary spacecraft and lay the groundwork for their future use in deep space science and exploration missions. Solar sails use sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like sail made of a lightweight, highly reflective material. This continuous photon pressure provides propellantless thrust, allowing for very high delta V maneuvers on long-duration, deep space exploration. Since reflected light produces thrust, solar sails require no onboard propellant. The Lightweight Integrated Solar Array and Transceiver (LISA-T) is a launch stowed, orbit deployed array on which thin-film photovoltaic and antenna elements are embedded. Inherently, small satellites are limited in surface area, volume, and mass allocation; driving competition between power, communications, and GN&C (guidance navigation and control) subsystems. This restricts payload capability and limits the value of these low-cost satellites. LISA-T is addressing this issue, deploying large-area arrays from a reduced volume and mass envelope - greatly enhancing power generation and communications capabilities of small spacecraft. The NEA Scout mission, funded by NASA's Advanced Exploration Systems Program and managed by NASA MSFC, will use the solar sail as its primary propulsion system, allowing it to survey and image one or more NEA's of interest for possible future human exploration. NEA Scout uses a 6U cubesat (to be provided by NASA's Jet Propulsion Laboratory), an 86 sq m solar sail and will weigh less than 12 kilograms. NEA Scout will be launched on the first flight of the Space Launch System in 2018. Similar in concept

Chinese large solar telescopes site survey

Science.gov (United States)

Liu, Yu

2017-04-01

In order to observe the solar surface with unprecedentedly higher resolution, Chinse solar physics society decided to launch their solar site survey project in 2010 as the first step to look for the best candidate sites for the Chinese next-generation large-aperture solar telescopes, i.e., the 5-8 meter Chinese Giant Solar Telescope, and the 1 meter level coronagraph. We have built two long-term monitoring sites in Daocheng, with altitudes of around 4800 meters above the sea level located in the large Shangri-La mountain area, and we have collected systematic site data since 2014. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that the large Shangri-La area owns the potential conditions of excellent seeing level and sufficient amount of clear-sky hours suitable for developing large solar telescopes. We will review the site survey progress and present the preliminary statistical results in this talk.

Solar Irradiance & On Grid Solar Power Systems with Net Metering in Pakistan

Directory of Open Access Journals (Sweden)

Haleema Qamar

2016-06-01

Full Text Available This paper presents a case study of solar irradiance and scope of on-grid solar power systems with net-metering in Pakistan. Detailed analysis of solar irradiance in Pakistan is being carried out by developing the dedicated solar excel sheets. The need of on grid solar power systems for the present energy crisis in developing countries like Pakistan is also discussed. It also presents the inclination of many countries especially USA and Europe towards it. Identification of barriers for implementing on grid net metered solar power systems in Pakistan along with solutions of these barriers is carried out.

High-Temperature-Short-Time Annealing Process for High-Performance Large-Area Perovskite Solar Cells.

Science.gov (United States)

Kim, Minjin; Kim, Gi-Hwan; Oh, Kyoung Suk; Jo, Yimhyun; Yoon, Hyun; Kim, Ka-Hyun; Lee, Heon; Kim, Jin Young; Kim, Dong Suk

2017-06-27

Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) are attracting tremendous research interest due to their high solar-to-electric power conversion efficiency with a high possibility of cost-effective fabrication and certified power conversion efficiency now exceeding 22%. Although many effective methods for their application have been developed over the past decade, their practical transition to large-size devices has been restricted by difficulties in achieving high performance. Here we report on the development of a simple and cost-effective production method with high-temperature and short-time annealing processing to obtain uniform, smooth, and large-size grain domains of perovskite films over large areas. With high-temperature short-time annealing at 400 °C for 4 s, the perovskite film with an average domain size of 1 μm was obtained, which resulted in fast solvent evaporation. Solar cells fabricated using this processing technique had a maximum power conversion efficiency exceeding 20% over a 0.1 cm 2 active area and 18% over a 1 cm 2 active area. We believe our approach will enable the realization of highly efficient large-area PCSs for practical development with a very simple and short-time procedure. This simple method should lead the field toward the fabrication of uniform large-scale perovskite films, which are necessary for the production of high-efficiency solar cells that may also be applicable to several other material systems for more widespread practical deployment.

Solar-Powered Refrigeration System

Science.gov (United States)

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2002-01-01

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

Solar Powered Refrigeration System

Science.gov (United States)

Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

2002-01-01

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

High-Efficiency, Multijunction Solar Cells for Large-Scale Solar Electricity Generation

Science.gov (United States)

Kurtz, Sarah

2006-03-01

A solar cell with an infinite number of materials (matched to the solar spectrum) has a theoretical efficiency limit of 68%. If sunlight is concentrated, this limit increases to about 87%. These theoretical limits are calculated using basic physics and are independent of the details of the materials. In practice, the challenge of achieving high efficiency depends on identifying materials that can effectively use the solar spectrum. Impressive progress has been made with the current efficiency record being 39%. Today's solar market is also showing impressive progress, but is still hindered by high prices. One strategy for reducing cost is to use lenses or mirrors to focus the light on small solar cells. In this case, the system cost is dominated by the cost of the relatively inexpensive optics. The value of the optics increases with the efficiency of the solar cell. Thus, a concentrator system made with 35%- 40%-efficient solar cells is expected to deliver 50% more power at a similar cost when compare with a system using 25%-efficient cells. Today's markets are showing an opportunity for large concentrator systems that didn't exist 5-10 years ago. Efficiencies may soon pass 40% and ultimately may reach 50%, providing a pathway to improved performance and decreased cost. Many companies are currently investigating this technology for large-scale electricity generation. The presentation will cover the basic physics and more practical considerations to achieving high efficiency as well as describing the current status of the concentrator industry. This work has been authored by an employee of the Midwest Research Institute under Contract No. DE- AC36-99GO10337 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow

Design of a gigawatt space solar power satellite using optical concentrator system

Science.gov (United States)

Dessanti, B.; Komerath, N.; Shah, S.

A 1-gigawatt space solar power satellite using a large array of individually pointable optical elements is identified as the key mass element of a large scale space solar power architecture using the Space Power Grid concept. The proposed satellite design enables a significant increase in specific power. Placed in sun-synchronous dynamic orbits near 2000km altitude, these satellites can maintain the constant solar view requirement of GEO-based architectures, while greatly reducing the beaming distance required, decreasing the required antenna size and in turn the overall system mass. The satellite uses an array of individually pointable optical elements (which we call a Mirasol Concentrator Array) to concentrate solar energy to an intensified feed target that feeds into the main heater of the spacecraft, similar conceptually to heliostat arrays. The spacecraft then utilizes Brayton cycle conversion to take advantage of non-linear power level scaling in order to generate high specific power values. Using phase array antennas, the power is then beamed at a millimeter wave frequency of 220GHz down to Earth. The design of the Mirasol concentrator system will be described and a detailed mass estimation of the system is developed. The technical challenges of pointing the elements and maintaining constant solar view is investigated. An end-to-end efficiency analysis is performed. Subsystem designs for the spacecraft are outlined. A detailed mass budget is refined to reflect reductions in uncertainty of the spacecraft mass, particularly in the Mirasol system. One of the key mass drivers of the spacecraft is the active thermal control system. The design of a lightweight thermal control system utilizing graphene sheets is also detailed.

Design consideration of solar powered cars

Energy Technology Data Exchange (ETDEWEB)

Koten, Hasan; Yilmaz, Mustafa; Zafer Gul, M. [Marmara University Mechanical Engineering Department (Turkey)], E-mail: hasan.koten@marmara.edu.tr

2011-07-01

With the coming shortage of fossil fuels and the rising concerns over the environment, it is important to develop new technologies that reduce both energy consumption and pollution at the same time. Using solar energy is a good solution which could meet the world's energy needs. The aim of this study is to present the design process in the production of a solar powered car. Designing a solar powered car is a difficult task as there are strict requirements in term of efficiency: the car must have low drag resistance, be light-weight, and have low rolling resistance. In addition this paper presents the use of the solar powered Stirling engine technology rather than a photovoltaic conversion system for vehicle propulsion. This study presented a design process in the construction of a solar powered car and is expected to provide a new topic of research in the transportation field.

Advances in Large-Scale Solar Heating and Long Term Storage in Denmark

DEFF Research Database (Denmark)

Heller, Alfred

2000-01-01

According to (the) information from the European Large-Scale Solar Heating Network, (See http://www.hvac.chalmers.se/cshp/), the area of installed solar collectors for large-scale application is in Europe, approximately 8 mill m2, corresponding to about 4000 MW thermal power. The 11 plants...... the last 10 years and the corresponding cost per collector area for the final installed plant is kept constant, even so the solar production is increased. Unfortunately large-scale seasonal storage was not able to keep up with the advances in solar technology, at least for pit water and gravel storage...... of the total 51 plants are equipped with long-term storage. In Denmark, 7 plants are installed, comprising of approx. 18,000-m2 collector area with new plants planned. The development of these plants and the involved technologies will be presented in this paper, with a focus on the improvements for Danish...

Solar Power Satellites: Reconsideration as Renewable Energy Source Based on Novel Approaches

Science.gov (United States)

Ellery, Alex

2017-04-01

Solar power satellites (SPS) are a solar energy generation mechanism that captures solar energy in space and converts this energy into microwave for transmission to Earth-based rectenna arrays. They offer a constant, high integrated energy density of 200 W/m2 compared to <10 W/m2 for other renewable energy sources. Despite this promise as a clean energy source, SPS have been relegated out of consideration due to their enormous cost and technological challenge. It has been suggested that for solar power satellites to become economically feasible, launch costs must decrease from their current 20,000/kg to <200/kg. Even with the advent of single-stage-to-orbit launchers which propose launch costs dropping to 2,000/kg, this will not be realized. Yet, the advantages of solar power satellites are many including the provision of stable baseload power. Here, I present a novel approach to reduce the specific cost of solar power satellites to 1/kg by leveraging two enabling technologies - in-situ resource utilization of lunar material and 3D printing of this material. Specifically, we demonstrate that electric motors may be constructed from lunar material through 3D printing representing a major step towards the development of self-replicating machines. Such machines have the capacity to build solar power satellites on the Moon, thereby bypassing the launch cost problem. The productive capacity of self-replicating machines favours the adoption of large constellations of small solar power satellites. This opens up additional clean energy options for combating climate change by meeting the demands for future global energy.

Detecting photovoltaic solar panels using hyperspectral imagery and estimating solar power production

Science.gov (United States)

Czirjak, Daniel

2017-04-01

Remote sensing platforms have consistently demonstrated the ability to detect, and in some cases identify, specific targets of interest, and photovoltaic solar panels are shown to have a unique spectral signature that is consistent across multiple manufacturers and construction methods. Solar panels are proven to be detectable in hyperspectral imagery using common statistical target detection methods such as the adaptive cosine estimator, and false alarms can be mitigated through the use of a spectral verification process that eliminates pixels that do not have the key spectral features of photovoltaic solar panel reflectance spectrum. The normalized solar panel index is described and is a key component in the false-alarm mitigation process. After spectral verification, these solar panel arrays are confirmed on openly available literal imagery and can be measured using numerous open-source algorithms and tools. The measurements allow for the assessment of overall solar power generation capacity using an equation that accounts for solar insolation, the area of solar panels, and the efficiency of the solar panels conversion of solar energy to power. Using a known location with readily available information, the methods outlined in this paper estimate the power generation capabilities within 6% of the rated power.

Solar cell power source system

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Yoichi; Toma, Kunio; Fukuwa, Shinji

1988-05-14

This invention aims to supply a power source system with stable power output by reducing the power loss due to switching in the voltage stabilization even when the power source is a solar cell with frequent voltage variation. For this purpose, in a solar cell power source system consisting of a solar cell, a storage battery, a switching regulator placed between the storage cell and the load, and a load, arrangement was made that, by judging the input voltage from the storage battery, switch-acting the transistor of the switching regulator, if the input voltage is higher than the specified voltage; is the input voltage is lower than the specified voltage, the transistor is put in a full-on state. By this, the supply voltage can be stabilized even when the voltage fluctuates, and system gets more efficient as the switching loss decreases in the voltage stabilizing means. (1 fig)

Comparison of sensorless dimming control based on building modeling and solar power generation

International Nuclear Information System (INIS)

Lee, Naeun; Kim, Jonghun; Jang, Cheolyong; Sung, Yoondong; Jeong, Hakgeun

2015-01-01

Artificial lighting in office buildings accounts for about 30% of the total building energy consumption. Lighting energy is important to reduce building energy consumption since artificial lighting typically has a relatively large energy conversion factor. Therefore, previous studies have proposed a dimming control using daylight. When applied dimming control, method based on building modeling does not need illuminance sensors. Thus, it can be applied to existing buildings that do not have illuminance sensors. However, this method does not accurately reflect real-time weather conditions. On the other hand, solar power generation from a PV (photovoltaic) panel reflects real-time weather conditions. The PV panel as the sensor improves the accuracy of dimming control by reflecting disturbance. Therefore, we compared and analyzed two types of sensorless dimming controls: those based on the building modeling and those that based on solar power generation using PV panels. In terms of energy savings, we found that a dimming control based on building modeling is more effective than that based on solar power generation by about 6%. However, dimming control based on solar power generation minimizes the inconvenience to occupants and can also react to changes in solar radiation entering the building caused by dirty window. - Highlights: • We conducted sensorless dimming control based on solar power generation. • Dimming controls using building modeling and solar power generation were compared. • The real time weather conditions can be considered by using solar power generation. • Dimming control using solar power generation minimizes inconvenience to occupants

Utilization of space technology for terrestrial solar power applications

Science.gov (United States)

Yasui, R. K.; Patterson, R. E.

1974-01-01

A description is given of the evolution of photovoltaic power systems designed and built for terrestrial applications, giving attention to problem areas which are currently impeding the further development of such systems. The rooftop testing of surplus solar panels is considered along with solar powered seismic observatories, solar powered portable radio sets, and design considerations identified from past experience. Present activities discussed are related to a solar powered on-shore beacon flasher system, a solar powered buoy, and a solar powered beacon flasher buoy.

Online short-term solar power forecasting

DEFF Research Database (Denmark)

Bacher, Peder; Madsen, Henrik; Nielsen, Henrik Aalborg

2009-01-01

This paper describes a new approach to online forecasting of power production from PV systems. The method is suited to online forecasting in many applications and in this paper it is used to predict hourly values of solar power for horizons of up to 36 hours. The data used is fifteen......-minute observations of solar power from 21 PV systems located on rooftops in a small village in Denmark. The suggested method is a two-stage method where first a statistical normalization of the solar power is obtained using a clear sky model. The clear sky model is found using statistical smoothing techniques....... Then forecasts of the normalized solar power are calculated using adaptive linear time series models. Both autoregressive (AR) and AR with exogenous input (ARX) models are evaluated, where the latter takes numerical weather predictions (NWPs) as input. The results indicate that for forecasts up to two hours...

High-Fidelity Solar Power Income Modeling for Solar-Electric UAVs: Development and Flight Test Based Verification

OpenAIRE

Oettershagen, Philipp

2017-01-01

Solar power models are a crucial element of solar-powered UAV design and performance analysis. During the conceptual design phase, their accuracy directly relates to the accuracy of the predicted performance metrics and thus the final design characteristics of the solar-powered UAV. Likewise, during the operations phase of a solar-powered UAV accurate solar power income models are required to predict and assess the solar power system performance. However, the existing literature on solar-powe...

Solar power generation system. Solar denryoku hassei sochi

Energy Technology Data Exchange (ETDEWEB)

Ohaku, T [Toshiba Corp., Kawasaki (Japan)

1990-12-21

In a conventional solar power generation system having shunt elements for controlling generated power and supplying the controlled power to a load, it is difficult to carry out a stable power control, because the shunt characteristics of an analogue shunt element driving circuit vary widely as compared with a digital shunt element driving circuit, as the temperature varies. According to the present invention, in a solar power generation system having a plurality of solar cells divided into two of the first and second cell groups and a first and a second shunt element driving means provided for the first and second cell groups, the first shunt element driving means is composed of a combination of a resisance and level shift diode arranged, and the second shunt element driving means is composed of a combination of a transistor and level shift diode arranged. A stable current control of the shunt elements can be therefore realized, because the control voltage range of the first and second shunt element driving means is changed so as to be expanded, as the temperature varies, so that their overlapped voltage range is kept constant. 7 figs.

Solar powered vehicles: From dream to reality

Energy Technology Data Exchange (ETDEWEB)

1986-09-01

The initiatives of the 'Schweizer Vereinigung fuer Sonnenenergie' (Swiss Association for Solar Energy) has added new impetus worldwide for the utilisation of solar energy. The Association organised the 'Tour de Sol', a race for vehicles propelled with the aid of solar energy. Solar vehicles with and without supplementary power, both standard production models and prototypes were eligible for the race. Before the start of the race, the solar-powered vehicles were 'filled up' with solar energy at a 'solar filling station'. The winner in the 'standard' section (a 2-seater small car for short distances) weighed in at 240 kg and attained a top speed of 100 km/h and a range of 150 km. The rear-wheel drive of this battery-powered vehicle was provided by 2 permanent magnet motors. A newly-developed nickel-zinc battery from the USA was available to power the twin engines. The energy requirement was the equivalent of less than 1 liter of petrol per 100 km.

A Remote Power Management Strategy for the Solar Energy Powered Bicycle

Directory of Open Access Journals (Sweden)

Chung-Hsing Chao

2011-12-01

Full Text Available In this paper, a solar energy powered bicycle by a wireless sensor network (WSN far-end network monitoring solar energy to transfer the electrical energy storage and the effectiveness analysis is proposed. In order to achieve this goal, an embarked ZigBee by a solar-powered bicycle the far-end wireless network supervisory system is setup. Experimental results prove that our prototype, the solar energy powered bicycle, can manage the solar energy for charging two Lead-Acid batteries pack. As a result, the user by the wireless network in parking period knows the data on the amount of immediate solar radiation, the degree of illumination, the ambient temperature, and electrical energy storage capacity information by the internet interface.

European sail tower SPS [Solar Power Satellite] concept

Energy Technology Data Exchange (ETDEWEB)

Seboldt, W.; Leipold, M.; Hanowski, N. [Institute of Space Sensor Technology and Planetary Exploration, Cologne (Germany). German Aerospace Center; Klimke, M. [HOPE Worldwide Deutschland, Berlin (Germany)

2001-06-01

Based on a DLR-study in 1998/99 on behalf of ESA/ESTEC called ''System Concepts, Architectures and Technologies for Space Exploration and Utilization (SE and U)'' a new design for an Earth-orbiting Solar Power Satellite (SPS) has been developed. The design is called ''European Sail Tower SPS'' and consists mainly of deplorable sail-like structures derived from the ongoing DLR/ESA solar sail technology development activity. Such an SPS satellite features an extremely light-weight and large tower-like orbital system and could supply Europe with significant amounts of electrical power generated by photovoltaic cells and subsequently transmitted to earth via microwaves. In order to build up the sail tower, 60 units - each consisting of a pair of square-shaped sails - are moved from LEO to GEO with electric propulsion and successively assembled in GEO robotically on a central strut. Each single sail has dimensions of 150 m x 150 m and is automatically deployed, using four diagonal lightweight carbon fiber (CFRP) booms which are initially rolled up on a central hub. The electric thrusters for the transport to GEO could also be used for orbit and attitude control of the assembled tower which has a total length of about 15 km and would be mainly gravity gradient stabilized. Employing thin film solar cell technology, each sail is used as a solar array and produces an electric power in orbit of about 3.7 MW{sub e}. A microwave antenna with a diameter of 1 km transmits the power to a 10 km rectenna on the ground. The total mass of this 450 MW SPS is about 2100 tons. First estimates indicate that the costs for one kWh delivered in this way could compete with present day energy costs, if launch costs would decrease by two orders of magnitude. Furthermore, mass production and large numbers of installed SPS systems must be assumed in order to lower significantly the production costs and to reduce the influence of the expensive technology

Large-scale solar heating

Energy Technology Data Exchange (ETDEWEB)

Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

1998-10-01

Solar heating market is growing in many European countries and annually installed collector area has exceeded one million square meters. There are dozens of collector manufacturers and hundreds of firms making solar heating installations in Europe. One tendency in solar heating is towards larger systems. These can be roof integrated, consisting of some tens or hundreds of square meters of collectors, or they can be larger centralized solar district heating plants consisting of a few thousand square meters of collectors. The increase of size can reduce the specific investments of solar heating systems, because e.g. the costs of some components (controllers, pumps, and pipes), planning and installation can be smaller in larger systems. The solar heat output can also be higher in large systems, because more advanced technique is economically viable

Space-based solar power conversion and delivery systems study. Volume 2: Engineering analysis of orbital systems

Science.gov (United States)

1976-01-01

Program plans, schedules, and costs are determined for a synchronous orbit-based power generation and relay system. Requirements for the satellite solar power station (SSPS) and the power relay satellite (PRS) are explored. Engineering analysis of large solar arrays, flight mechanics and control, transportation, assembly and maintenance, and microwave transmission are included.

Solar thermal and concentrated solar power barometer

International Nuclear Information System (INIS)

2013-01-01

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

Development of nonmetallic solar collector and solar-powered pump

Science.gov (United States)

Parker, J. C.

1979-01-01

Design and building of two unique components for solar heating (1. flatplate solar collector using no metal components, and 2. solar powered pump for heating and cooling systems are outlined in report. Report also discusses hardware, deliverable end items, problems encountered during fabrication and testing, and performance certification.

Solar power generating device. Solar denryoku hassei sochi

Energy Technology Data Exchange (ETDEWEB)

Hayashi, E

1990-02-06

Concerning the existing solar power generating device using the analogue sequential partial shunt system, the number of interface line between the solar cell panel and the shunt dissipater is enormous and complicated in addition to the increased temperature rise of the shunt transistor in its working condition. Furthermore, concerning the digital sequential full shunt system, the above temperature rise becomes less, but the above number of interface line is likewise enormous. In order to remove the above defects, the solar power generating device which this invention concerns has the features that, in each row of solar cells connected to shunt transistors which are controlled respectively in a manner of on (saturation)/off independently in accordance with the amount of surplus electric power, the number of parallel connection of the unit cell circuits composing the each row above is made to be the different number respectively. Besides, it is proposed to have the feature in particular that such a number is made to be the number of 2 {sup n} (n is from zero to any integer, m) where n is increased by one progressively. 5 figs.

Flat plate solar collector for water pre-heating using concentrated solar power (CSP)

Science.gov (United States)

Peris, Leonard Sunny; Shekh, Md. Al Amin; Sarker, Imran

2017-12-01

Numerous attempt and experimental conduction on different methods to harness energy from renewable sources are being conducted. This study is a contribution to the purpose of harnessing solar energy as a renewable source by using flat plate solar collector medium to preheat water. Basic theory of solar radiation and heat convection in water (working fluid) has been combined with heat conduction process by using copper tubes and aluminum absorber plate in a closed conduit, covered with a glazed through glass medium. By this experimental conduction, a temperature elevation of 35°C in 10 minutes duration which is of 61.58% efficiency range (maximum) has been achieved. The obtained data and experimental findings are validated with the theoretical formulation and an experimental demonstration model. A cost effective and simple form of heat energy extraction method for space heating/power generation has been thoroughly discussed with possible industrial implementation possibilities. Under-developed and developing countries can take this work as an illustration for renewable energy utilization for sustainable energy prospect. Also a full structure based data to derive concentrated solar energy in any geographical location of Bangladesh has been outlined in this study. These research findings can contribute to a large extent for setting up any solar based power plant in Bangladesh irrespective of its installation type.

Assessment of distributed solar power systems: Issues and impacts

Science.gov (United States)

Moyle, R. A.; Chernoff, H.; Schweizer, T. C.; Patton, J. B.

1982-11-01

The installation of distributed solar-power systems presents electric utilities with a host of questions. Some of the technical and economic impacts of these systems are discussed. Among the technical interconnect issues are isolated operation, power quality, line safety, and metering options. Economic issues include user purchase criteria, structures and installation costs, marketing and product distribution costs, and interconnect costs. An interactive computer program that allows easy calculation of allowable system prices and allowable generation-equipment prices was developed as part of this project. It is concluded that the technical problems raised by distributed solar systems are surmountable, but their resolution may be costly. The stringent purchase criteria likely to be imposed by many potential system users and the economies of large-scale systems make small systems (less than 10 to 20 kW) less attractive than larger systems. Utilities that consider life-cycle costs in making investment decisions and third-party investors who have tax and financial advantages are likely to place the highest value on solar-power systems.

Emerging large-scale solar heating applications

International Nuclear Information System (INIS)

Wong, W.P.; McClung, J.L.

2009-01-01

Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

Emerging large-scale solar heating applications

Energy Technology Data Exchange (ETDEWEB)

Wong, W.P.; McClung, J.L. [Science Applications International Corporation (SAIC Canada), Ottawa, Ontario (Canada)

2009-07-01

Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

Solar-pumped lasers for space power transmission

Science.gov (United States)

Taussig, R.; Bruzzone, C.; Nelson, L.; Quimby, D.; Christiansen, W.

1979-01-01

Multi-Megawatt CW solar-pumped lasers appear to be technologically feasible for space power transmission in the 1990s time frame. A new concept for a solar-pumped laser is presented which utilizes an intermediate black body cavity to provide a uniform optical pumping environment for the lasant, either CO or CO2. Reradiation losses are minimized with resulting high efficiency operation. A 1 MW output laser may weigh as little as 8000 kg including solar collector, black body cavity, laser cavity and ducts, pumps, power systems and waste heat radiator. The efficiency of such a system will be on the order of 10 to 20%. Details of the new concept, laser design, comparison to competing solar-powered lasers and applications to a laser solar power satellite (SPS) concept are presented.

The New Solar System: China’s Evolving Solar Industry and Its Implications for Competitive Solar Power in the United States and the World

Energy Technology Data Exchange (ETDEWEB)

Ball, Jeffrey [Stanford Univ., CA (United States); Reicher, Dan [Stanford Univ., CA (United States); Sun, Xiaojing [Stanford Univ., CA (United States); Pollock, Caitlin [Stanford Univ., CA (United States)

2017-03-08

Solar power is undergoing a revolution. Over the past decade, an energy source as old as the planet and theoretically all but limitless has plummeted in cost and begun in some places to be harnessed in large volume. This dynamic is disrupting the modern energy system and, as energy disruptions always do, rattling the geopolitical order. In the process, the industry that produces the equipment to convert sunlight into electricity is simultaneously reeling, consolidating, and surging. These twin transformations—one of the global energy system, one of the global solar industry—carry profound implications for national economies and for the planet. At the center of both transformations sits China. The New Solar System illuminates key and little- understood changes that are remaking the solar enterprise—in China and thus in the world. Based on this analysis, it recommends changes in U.S. solar policy—particularly timely with a new U.S. administration and Congress—that would put solar power on a more economically sensible path toward environmentally significant growth. The New Solar System does not seek to enable any country to beat another in the global solar industry. It seeks instead to help all countries find their most effective places. By better understanding and playing to their comparative strengths in the solar business, countries would achieve two key objectives. They would reduce the cost for the world of scaling up solar power. And they would be better positioned to fashion policies that maximized the long-term benefit to their own economies from solar’s global growth.

Microcontroller Based Solar Charge Controller for Power Application

OpenAIRE

Mr. Vikas Khare

2012-01-01

Photovoltaic cell converts solar energy directly into electricity. This paper describes a design of microcontroller based solar charge controller for power application.[2] The work of the Paper is to charge a 12 volt battery by using a 50 watt solar panel with maximum power. This circuit regulates the charging of battery in a solar system by monitoring battery voltage and switching the solar or other power source off when the battery reached a preset value.[1] The microprocessor based charge ...

Possibilities for retrofitting of the existing thermal electric power plants using solar power technologies

International Nuclear Information System (INIS)

Matjanov, Erkinjon K.; Abduganieva, Farogat A.; Aminov, Zarif Z.

2012-01-01

Full text: Total installed electric power output of the existing thermal electric power plants in Uzbekistan is reaches 12 GW. Thermal electric power plants, working on organic fuel, produce around 88 % of the electricity in the country. The emission coefficient of CO 2 gases is 620 gram/kwph. Average electric efficiency of the thermal electric power plants is 32.1 %. The mentioned above data certifies, that the existing thermal electric power plants of Uzbekistan are physically and morally aged and they need to be retrofitted. Retrofitting of the existing thermal electric power plants can be done by several ways such as via including gas turbine toppings, by using solar technologies, etc. Solar thermal power is a relatively new technology which has already shown its enormous promise. With few environmental impacts and a massive resource, it offers a comparable opportunity to the sunniest Uzbekistan. Solar thermal power uses direct sunlight, so it must be sited in regions with high direct solar radiation. In many regions, one square km of land is enough to generate as much as 100-120 GWh of electricity per year using the solar thermal technology. This is equivalent to the annual production of a 50 MW conventional coal or gas-fired mid-load power plant. Solar thermal power plants can be designed for solar-only or for hybrid operation. Producing electricity from the energy in the sun's rays is a straightforward process: direct solar radiation can be concentrated and collected by a range of Concentrating Solar Power technologies to provide medium- to high temperature heat. This heat is then used to operate a conventional power cycle, for example through a steam turbine or a Stirling engine. Solar heat collected during the day can also be stored in liquid or solid media such as molten salts, ceramics, concrete or, in the future, phase-changing salt mixtures. At night, it can be extracted from the storage medium thereby continuing turbine operation. Currently, the

Control of Power and Voltage of Solar Grid Connected

OpenAIRE

Allah, Boucetta Abd; Djamel, Labed

2016-01-01

Renewable energy is high on International agendas. Currently, grid-connected photovoltaic systems are a popular technology to convert solar energy into electricity. Control of power injected into the grid, maximum power point, high efficiency, and low total harmonic distortion of the currents injected into the grid are the requirements for inverter connection into the grid. Consequently, the performance of the inverters connected to the grid depends largely on the control strategy applied. In...

Solar Powered Automatic Shrimp Feeding System

Directory of Open Access Journals (Sweden)

Dindo T. Ani

2015-12-01

Full Text Available - Automatic system has brought many revolutions in the existing technologies. One among the technologies, which has greater developments, is the solar powered automatic shrimp feeding system. For instance, the solar power which is a renewable energy can be an alternative solution to energy crisis and basically reducing man power by using it in an automatic manner. The researchers believe an automatic shrimp feeding system may help solve problems on manual feeding operations. The project study aimed to design and develop a solar powered automatic shrimp feeding system. It specifically sought to prepare the design specifications of the project, to determine the methods of fabrication and assembly, and to test the response time of the automatic shrimp feeding system. The researchers designed and developed an automatic system which utilizes a 10 hour timer to be set in intervals preferred by the user and will undergo a continuous process. The magnetic contactor acts as a switch connected to the 10 hour timer which controls the activation or termination of electrical loads and powered by means of a solar panel outputting electrical power, and a rechargeable battery in electrical communication with the solar panel for storing the power. By undergoing through series of testing, the components of the modified system were proven functional and were operating within the desired output. It was recommended that the timer to be used should be tested to avoid malfunction and achieve the fully automatic system and that the system may be improved to handle changes in scope of the project.

Power management circuits for self-powered systems based on micro-scale solar energy harvesting

Science.gov (United States)

Yoon, Eun-Jung; Yu, Chong-Gun

2016-03-01

In this paper, two types of power management circuits for self-powered systems based on micro-scale solar energy harvesting are proposed. First, if a solar cell outputs a very low voltage, less than 0.5 V, as in miniature solar cells or monolithic integrated solar cells, such that it cannot directly power the load, a voltage booster is employed to step up the solar cell's output voltage, and then a power management unit (PMU) delivers the boosted voltage to the load. Second, if the output voltage of a solar cell is enough to drive the load, the PMU directly supplies the load with solar energy. The proposed power management systems are designed and fabricated in a 0.18-μm complementary metal-oxide-semiconductor process, and their performances are compared and analysed through measurements.

Concentrating solar thermal power.

Science.gov (United States)

Müller-Steinhagen, Hans

2013-08-13

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

Distributed Solar Photovoltaic Power Production - Technology and Benefits

Energy Technology Data Exchange (ETDEWEB)

Matos, Al [PSE& G; Stuby, Rick [Petra Solar

2011-11-02

As part of its nationally recognized Solar 4 All program, PSE&G has partnered with Petra Solar to deploy the world’s first and largest pole attached solar project. The project, based on Petra Solar’s distributed Smart Solar solution, will create a 40 megawatt solar “virtual power plant.” In deployment as 200,000 individual grid-connected solar power producers on utility poles in PSE&G territory, Petra Solar SunWave® solutions leverage Smart Grid communications and high-tech panel-level inverters to implement a robust system with many technical benefits over traditional solar photovoltaic solutions. The program overview, deployment model, smart grid communications and enabling inverter technology and safety features will be presented, as well the future challenges of, and solutions for, solar power intermittency as photovoltaic penetration on the electric grid increases.

Solar thermal electric power information user study

Energy Technology Data Exchange (ETDEWEB)

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

1981-02-01

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

A wireless soil moisture sensor powered by solar energy.

Directory of Open Access Journals (Sweden)

Mingliang Jiang

Full Text Available In a variety of agricultural activities, such as irrigation scheduling and nutrient management, soil water content is regarded as an essential parameter. Either power supply or long-distance cable is hardly available within field scale. For the necessity of monitoring soil water dynamics at field scale, this study presents a wireless soil moisture sensor based on the impedance transform of the frequency domain. The sensor system is powered by solar energy, and the data can be instantly transmitted by wireless communication. The sensor electrodes are embedded into the bottom of a supporting rod so that the sensor can measure soil water contents at different depths. An optimal design with time executing sequence is considered to reduce the energy consumption. The experimental results showed that the sensor is a promising tool for monitoring moisture in large-scale farmland using solar power and wireless communication.

Switch: a planning tool for power systems with large shares of intermittent renewable energy.

Science.gov (United States)

Fripp, Matthias

2012-06-05

Wind and solar power are highly variable, so it is it unclear how large a role they can play in future power systems. This work introduces a new open-source electricity planning model--Switch--that identifies the least-cost strategy for using renewable and conventional generators and transmission in a large power system over a multidecade period. Switch includes an unprecedented amount of spatial and temporal detail, making it possible to address a new type of question about the optimal design and operation of power systems with large amounts of renewable power. A case study of California for 2012-2027 finds that there is no maximum possible penetration of wind and solar power--these resources could potentially be used to reduce emissions 90% or more below 1990 levels without reducing reliability or severely raising the cost of electricity. This work also finds that policies that encourage customers to shift electricity demand to times when renewable power is most abundant (e.g., well-timed charging of electric vehicles) could make it possible to achieve radical emission reductions at moderate costs.

Development of Solar Powered Irrigation System

International Nuclear Information System (INIS)

Abdelkerim, A I; Eusuf, M M R Sami; Salami, M J E; Aibinu, A; Eusuf, M A

2013-01-01

Development of a solar powered irrigation system has been discussed in this paper. This system would be SCADA-based and quite useful in areas where there is plenty of sunshine but insufficient water to carry out farming activities, such as rubber plantation, strawberry plantation, or any plantation, that requires frequent watering. The system is powered by solar system as a renewable energy which uses solar panel module to convert Sunlight into electricity. The development and implementation of an automated SCADA controlled system that uses PLC as a controller is significant to agricultural, oil and gas monitoring and control purpose purposes. In addition, the system is powered by an intelligent solar system in which solar panel targets the radiation from the Sun. Other than that, the solar system has reduced energy cost as well as pollution. The system is equipped with four input sensors; two soil moisture sensors, two level detection sensors. Soil moisture sensor measures the humidity of the soil, whereas the level detection sensors detect the level of water in the tank. The output sides consist of two solenoid valves, which are controlled respectively by two moistures sensors

Design approach for solar cell and battery of a persistent solar powered GPS tracker

Science.gov (United States)

Sahraei, Nasim; Watson, Sterling M.; Pennes, Anthony; Marius Peters, Ian; Buonassisi, Tonio

2017-08-01

Sensors with wireless communication can be powered by photovoltaic (PV) devices. However, using solar power requires thoughtful design of the power system, as well as a careful management of the power consumption, especially for devices with cellular communication (because of their higher power consumption). A design approach can minimize system size, weight, and/or cost, while maximizing device performance (data transmission rate and persistence). In this contribution, we describe our design approach for a small form-factor, solar-powered GPS tracker with cellular communication. We evaluate the power consumption of the device in different stages of operation. Combining measured power consumption and the calculated energy-yield of a solar cell, we estimate the battery capacity and solar cell area required for 5 years of continuous operation. We evaluate trade-offs between PV and battery size by simulating the battery state of charge. The data show a trade-off between battery capacity and solar-cell area for given target data transmission rate and persistence. We use this analysis to determine the combination of solar panel area and battery capacity for a given application and the data transmission rate that results in minimum cost or total weight of the system.

Recipe for success in solar power marketing

International Nuclear Information System (INIS)

Frauenfelder, S.

2000-01-01

This article presents the results of a campaign run jointly by the Swiss Federal Office of Energy and the Association of Swiss Electricity Utilities called 'Solar Power from your Utility'. An analysis of solar power marketing efforts made by ten utilities is presented. The results of assessments of these market measures made by solar power customers and non-customers are presented and questions of pricing, product-image and product-confidence are discussed. Finally, suggestions for the optimisation of the marketing measures are made

Online Short-term Solar Power Forecasting

DEFF Research Database (Denmark)

Bacher, Peder; Madsen, Henrik; Nielsen, Henrik Aalborg

2011-01-01

This poster presents two approaches to online forecasting of power production from PV systems. The methods are suited for online forecasting in many applications and here they are used to predict hourly values of solar power for horizons up to 32 hours.......This poster presents two approaches to online forecasting of power production from PV systems. The methods are suited for online forecasting in many applications and here they are used to predict hourly values of solar power for horizons up to 32 hours....

Small Hybrid Solar Power System

OpenAIRE

Kane, El Hadj Malick; Larrain, Diego; Favrat, Daniel

2001-01-01

This paper introduces a novel of mini-hybrid solar power plant integrating a field of solar concentrators, two superposed Organic Rankine Cycles (ORC) and a (bio)Diesel engine. Turbines for the organic Rankine Cycles are hermetic scroll expander-generators. Sun tracking solar collectors are composed of rows of flat mirror bands (CEP) arranged in a plane, which focus the solar energy onto a collector tube similar to those used in SEGS plant in California. The wast...

Small Hybrid Solar Power System

OpenAIRE

Kane, El Hadj Malick; Favrat, Daniel; Larrain, Diego; Allani, Yassine

2003-01-01

This paper introduces a novel of mini-hybrid solar power plant integrating a field of solar concentrators, two superposed Organic Rankine Cycles (ORC) and a (bio)Diesel engine. Turbines for the organic Rankine Cycles are hermetic scroll expander-generators. Sun tracking solar collectors are composed of rows of flat mirror bands (CEP) arranged in a plane, which focus the solar energy onto a collector tube similar to those used in SEGS plant in California. The waste heat from both...

Performance analysis of conventional and sloped solar chimney power plants in China

International Nuclear Information System (INIS)

Cao Fei; Zhao Liang; Li Huashan; Guo Liejin

2013-01-01

The solar chimney power plant (SCPP) has been accepted as one of the most promising approaches for future large-scale solar energy applications. This paper reports on a heat transfer model that is used to compare the performance of a conventional solar chimney power plant (CSCPP) and two sloped solar chimney power plants (SSCPPs) with the collector oriented at 30° and 60°, respectively. The power generation from SCPPs at different latitudes in China is also analyzed. Results indicate that the larger solar collector angle leads to improved performance in winter but results in lower performance in summer. It is found that the optimal collector angle to achieve the maximum power in Lanzhou, China, is around 60°. Main factors that influence the performance of SCPPs also include the system height and the air thermophysical characteristics. The ground energy loss, reflected solar radiation, and kinetic loss at the chimney outlet are the main energy losses in SCPPs. The studies also show SSCPPs are more suitable for high latitude regions in Northwest China, but CSCPPs are suggested to be built in southeastern and eastern parts of China with the combination to the local agriculture. - Highlights: ► The optimum collector angle for maximum power generation is 60° in Lanzhou. ► Main parameters influencing performances are the system height and air property. ► Ground loss, reflected loss and outlet kinetic loss are the main energy losses. ► The sloped styles are suitable for Northwest China. ► The conventional styles are suitable for Southeast and East China.

Large solar energy systems within IEA task 14

NARCIS (Netherlands)

Geus, A.C. de; Isakson, P.; Bokhoven, T.P.; Vanoli, K.; Tepe, R.

1996-01-01

Within IEA Task 14 (Advanced Solar Systems) a working group was established dealing with large advanced solar energy systems (the Large Systems Working group). The goal of this working group was to generate a common base of experiences for the design and construction of advanced large solar systems.

Optimal Site Selection of Wind-Solar Complementary Power Generation Project for a Large-Scale Plug-In Charging Station

Directory of Open Access Journals (Sweden)

Wenjun Chen

2017-10-01

Full Text Available The wind-solar hybrid power generation project combined with electric vehicle charging stations can effectively reduce the impact on the power system caused by the random charging of electric cars, contribute to the in-situ wind-solar complementary system and reduce the harm arising from its output volatility. In this paper, the site selection index system of a landscape complementary power generation project is established by using the statistical methods and statistical analysis in the literature. Subsequently, using the Analytic Network Process to calculate the index weight, a cloud model was used in combination with preference ranking organization method for enrichment evaluations to transform and sort uncertain language information. Finally, using the results of the decision-making for the location of the Shanghai wind-solar complementary project and by carrying out contrast analysis and sensitivity analysis, the superiority and stability of the decision model constructed in this study was demonstrated.

The solar two power tower project

International Nuclear Information System (INIS)

Chavez, J.M.; Klimas, P.C.; Laquil, P. de III; Skowronski, M.

1993-01-01

A consortium of United States utility concerns led by Southern California Edison Company (SCE) has begun a cooperative project with the U.S. Department of Energy (DOE) and industry to convert the 10-MWe Solar One Tower Pilot Plant to molten nitrate salt technology. Successful operation of the convert plant to be called Solar Two, will reduce the economic risks in building the initial commercial power tower projects and accelerate the commercial acceptance of this promising renewable energy technology. In a molten salt power tower plant, sunlight is concentrated by a field of sun-tracking mirrors, called heliostats, onto a centrally located receiver, atop a tower. Molten salt is heated in the receiver and stored until it is needed to generate steam to power a conventional turbine generator. Joining the SCE and DOE in sponsoring in sponsoring this project are the following organizations: Los Alamos department of Water Power, Idaho Power Company, PacifiCorp, Pacific Gas and Electric Company, Sacramento Municipal Utility District, Arizona Public Service Company, Salt River Project, City of Pasadena, California Energy Commission, Electric Power Research Institute, South Coast Air Quality Commission, Electric Power research Institute, South Coast Air Quality Management District, and Bechtel Corporation. The Solar Two project will convert the Solar One heat transfer system from a water/steam type to molten nitrate salt by replacing the water/steam receiver and oil/rock thermal storage system with a nitrate salt receiver, salt thermal storage, and steam generator. The estimate cost of Solar Two, including 3-year test period, is 48.5 millions. The plant will be on line in early 1995. (authors)

Peak Power Markets for Satellite Solar Power

Science.gov (United States)

Landis, Geoffrey A.

2002-01-01

This paper introduces first Indonesia, comprises 15,000 islands, has land area of two millions square kilometers. Extending from 95 to 141 degrees East longitude and from 6 degrees North to 11 degrees South latitude. Further the market of the Space Solar Power/SPS must be worldwide, including Indonesia. As we know, it can provide electricity anywhere in the world from the Earth's orbit, mostly Indonesia an equator country. We have to perform case studies of various countries to understand their benefits and disadvantages provided by the SSP, because each country has much different condition on energy from other countries. We are at the moment starting the international collaboration between Indonesia and Japan to carry out the case study for Indonesia. We understand that in Indonesia itself each province has much different micro-climate between one province compared to the other. In Japan, METI (Ministry of Economy, Trade and Industry) has already organized a committee to investigate the feasibility of Space Solar Power and to make a plan to launch a space demonstration of the SPS. While, Indonesia is quickly developing economy and increasing their energy demand. We are investigating the detailed energy conditions of Indonesia, the benefits and disadvantages of the Space Solar Power for Indonesia. Especially, we will perform the investigation on the receiving system for the Japanese pilot Space Power Satellite.

Demonstration of Essential Reliability Services by a 300-MW Solar Photovoltaic Power Plant

Energy Technology Data Exchange (ETDEWEB)

Loutan, Clyde; Klauer, Peter; Chowdhury, Sirajul; Hall, Stephen; Morjaria, Mahesh; Chadliev, Vladimir; Milam, Nick; Milan, Christopher; Gevorgian, Vahan

2017-03-24

The California Independent System Operator (CAISO), First Solar, and the National Renewable Energy Laboratory (NREL) conducted a demonstration project on a large utility-scale photovoltaic (PV) power plant in California to test its ability to provide essential ancillary services to the electric grid. With increasing shares of solar- and wind-generated energy on the electric grid, traditional generation resources equipped with automatic governor control (AGC) and automatic voltage regulation controls -- specifically, fossil thermal -- are being displaced. The deployment of utility-scale, grid-friendly PV power plants that incorporate advanced capabilities to support grid stability and reliability is essential for the large-scale integration of PV generation into the electric power grid, among other technical requirements. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, PV power plants can be used to mitigate the impact of variability on the grid, a role typically reserved for conventional generators. In August 2016, testing was completed on First Solar's 300-MW PV power plant, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to use grid-friendly controls to provide essential reliability services. These data showed how the development of advanced power controls can enable PV to become a provider of a wide range of grid services, including spinning reserves, load following, voltage support, ramping, frequency response, variability smoothing, and frequency regulation to power quality. Specifically, the tests conducted included various forms of active power control such as AGC and frequency regulation; droop response; and reactive power, voltage, and power factor controls. This project demonstrated that advanced power electronics and solar generation can be

Reliability Assessment Considering the Coordination of Wind Power, Solar Energy and Energy Storage

Institute of Scientific and Technical Information of China (English)

WANG Haiying; BAI Xiaomin; XU Jing

2012-01-01

Large-scale integration of wind power and solar photovoltaic （PV） power in an electric grid can result in a high operating risk due to their randomness and intermi- ttency. Energy storage （ES） can be used to coordinate with them to reduce this risk by improving supply continuity. It is therefore important to evaluate the reliability benefits of systems consist of wind power, solar photovoltaic power and energy storage. The objective of this paper is to evaluate how the parameters such as the capacity and characteristics of ES and the configuration of a hybrid generation system （HGS） affect the system adequacy based on the sequential Monte Carlo approach.

Organic solar cell modules for specific applications-From energy autonomous systems to large area photovoltaics

International Nuclear Information System (INIS)

Niggemann, M.; Zimmermann, B.; Haschke, J.; Glatthaar, M.; Gombert, A.

2008-01-01

We report on the development of two types of organic solar cell modules one for energy autonomous systems and one for large area energy harvesting. The first requires a specific tailoring of the solar cell geometry and cell interconnection in order to power an energy autonomous system under its specific operating conditions. We present an organic solar cell module with 22 interconnected solar cells. A power conversion efficiency of 2% under solar illumination has been reached on the active area of 46.2 cm 2 . A voltage of 4 V at the maximum power point has been obtained under indoor illumination conditions. Micro contact printing of a self assembling monolayer was employed for the patterning of the polymer anode. Large area photovoltaic modules have to meet the requirements on efficiency, lifetime and costs simultaneously. To minimize the production costs, a suitable concept for efficient reel-to-reel production of large area modules is needed. A major contribution to reduce the costs is the substitution of the commonly used indium tin oxide electrode by a cheap material. We present the state of the art of the anode wrap through concept as a reel-to-reel suited module concept and show comparative calculations of the module interconnection of the wrap through concept and the standard ITO-based cell architecture. As a result, the calculated overall module efficiency of the anode wrap through module exceeds the overall efficiency of modules based on ITO on glass (sheet resistance 15 Ω/square) and on foils (sheet resistance 60 Ω/square)

Consumer attitudes towards domestic solar power systems

International Nuclear Information System (INIS)

Faiers, Adam; Neame, Charles

2006-01-01

The success of the UK policy to reduce carbon emissions is partly dependent on the ability to persuade householders to become more energy efficient, and to encourage installation of domestic solar systems. Solar power is an innovation in the UK but the current policy of stimulating the market with grants is not resulting in widespread adoption. This case study, using householders in central England, investigates householder attitudes towards characteristics of solar systems and identifies some of the barriers to adoption. The study utilises Diffusion of Innovations theory to identify attitudes towards system attributes, and isolates the characteristics that are preventing a pragmatic 'early majority' from adopting the technology. A group of 'early adopters', and a group of assumed 'early majority' adopters of solar power were surveyed and the results show that overall, although the 'early majority' demonstrate a positive perception of the environmental characteristics of solar power, its financial, economic and aesthetic characteristics are limiting adoption. Differences exist between the two groups showing support for the concept of a 'chasm' between adopter categories after Moore (Crossing the Chasm: Marketing and Selling High-tech Products to Mainstream Customers, second ed. Harper Perennial, New York). However, if consumers cannot identify the relative advantage of solar power over their current sources of power, which is supplied readily and cheaply through a mains system, it is unlikely that adoption will follow. Recommendations concerning the marketing and development of solar products are identified

Rankine-Brayton engine powered solar thermal aircraft

Science.gov (United States)

Bennett, Charles L [Livermore, CA

2009-12-29

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

Rankline-Brayton engine powered solar thermal aircraft

Science.gov (United States)

Bennett, Charles L [Livermore, CA

2012-03-13

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

Simultaneous Solar Maximum Mission (SMM) and very large array observations of solar active regions

Science.gov (United States)

Lang, K. R.

1986-01-01

The research deals mainly with Very Large Array and Solar Maximum Mission observations of the ubiquitous coronal loops that dominate the structure of the low corona. As illustrated, the observations of thermal cyclotron lines at microwave wavelengths provide a powerful new method of accurately specifying the coronal magnetic field strength. Processes are delineated that trigger solar eruptions from coronal loops, including preburst heating and the magnetic interaction of coronal loops. Evidence for coherent burst mechanisms is provided for both the Sun and nearby stars, while other observations suggest the presence of currents that may amplify the coronal magnetic field to unexpectedly high levels. The existence is reported of a new class of compact, variable moving sources in regions of apparently weak photospheric field.

Wireless Power Transmission Options for Space Solar Power

Science.gov (United States)

Potter, Seth; Davis, Dean; Born, Martin; Bayer, Martin; Howell, Joe; Mankins, John

2008-01-01

Space Solar Power (SSP), combined with Wireless Power Transmission (WPT), offers the far-term potential to solve major energy problems on Earth. In the long term, we aspire to beam energy to Earth from geostationary Earth orbit (GEO), or even further distances in space. In the near term, we can beam power over more moderate distances, but still stretch the limits of today s technology. In recent studies, a 100 kWe-class "Power Plug" Satellite and a 10 kWe-class Lunar Polar Solar Power outpost have been considered as the first steps in using these WPT options for SSP. Our current assessments include consideration of orbits, wavelengths, and structural designs to meet commercial, civilian government, and military needs. Notional transmitter and receiver sizes are considered for use in supplying 5 to 40 MW of power. In the longer term, lunar or asteroidal material can be used. By using SSP and WPT technology for near-term missions, we gain experience needed for sound decisions in designing and developing larger systems to send power from space to Earth.

Swiss solar power statistics 2007 - Significant expansion

International Nuclear Information System (INIS)

Hostettler, T.

2008-01-01

This article presents and discusses the 2007 statistics for solar power in Switzerland. A significant number of new installations is noted as is the high production figures from newer installations. The basics behind the compilation of the Swiss solar power statistics are briefly reviewed and an overview for the period 1989 to 2007 is presented which includes figures on the number of photovoltaic plant in service and installed peak power. Typical production figures in kilowatt-hours (kWh) per installed kilowatt-peak power (kWp) are presented and discussed for installations of various sizes. Increased production after inverter replacement in older installations is noted. Finally, the general political situation in Switzerland as far as solar power is concerned are briefly discussed as are international developments.

The prospects for cost competitive solar PV power

International Nuclear Information System (INIS)

Reichelstein, Stefan; Yorston, Michael

2013-01-01

New solar Photovoltaic (PV) installations have grown globally at a rapid pace in recent years. We provide a comprehensive assessment of the cost competitiveness of this electric power source. Based on data available for the second half of 2011, we conclude that utility-scale PV installations are not yet cost competitive with fossil fuel power plants. In contrast, commercial-scale installations have already attained cost parity in the sense that the generating cost of power from solar PV is comparable to the retail electricity prices that commercial users pay, at least in certain parts of the U.S. This conclusion is shown to depend crucially on both the current federal tax subsidies for solar power and an ideal geographic location for the solar installation. Projecting recent industry trends into the future, we estimate that utility-scale solar PV facilities are on track to become cost competitive by the end of this decade. Furthermore, commercial-scale installations could reach “grid parity” in about ten years, if the current federal tax incentives for solar power were to expire at that point. - Highlights: ► Assessment of the cost competitiveness of new solar Photovoltaic (PV) installations. ► Utility-scale PV installations are not yet cost competitive with fossil fuel power plants. ► Commercial-scale installations have already attained cost parity in certain parts of the U.S. ► Utility-scale solar PV facilities are on track to become cost competitive by the end of this decade

Marketing of green electrons. Solar-power stock exchanges

International Nuclear Information System (INIS)

Nussbaumer-Waelti, E.

1999-01-01

An independent power producer evaluates the current solar-power stock exchanges in Switzerland. Most stock exchanges have been created by electric utilities which want to deliver 'green' power to those of their clients asking for. A first group of solar-power stock exchanges offer to take over the produced solar power at a marginal price. Among them, some organise a competition between the potential solar-power producers, in order to press down the investment cost for the new photovoltaic plants to build. Other stock exchanges propose a periodical adaptation of the prices, especially an adaptation to the capital interest rate. For sure, the total length of the time period for which the contract is established is one of the decisive factors. Because no bank is ready to grant a credit for such an investment without having seen a long-running take-over contract for the produced power [de

Low-cost solar electric power

CERN Document Server

Fraas, Lewis M

2014-01-01

?This book describes recent breakthroughs that promise major cost reductions in solar energy production in a clear and highly accessible manner. The author addresses the three key areas that have commonly resulted in criticism of solar energy in the past: cost, availability, and variability. Coverage includes cutting-edge information on recently developed 40? efficient solar cells, which can produce double the power of currently available commercial cells. The discussion also highlights the potentially transformative emergence of opportunities for integration of solar energy storage and natura

Concentrated solar thermal power - Now

Energy Technology Data Exchange (ETDEWEB)

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

2005-09-15

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

Beam-Forming Concentrating Solar Thermal Array Power Systems

Science.gov (United States)

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

2016-01-01

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

Future Market Share of Space Solar Electric Power Under Open Competition

Science.gov (United States)

Smith, S. J.; Mahasenan, N.; Clarke, J. F.; Edmonds, J. A.

2002-01-01

This paper assesses the value of Space Solar Power deployed under market competition with a full suite of alternative energy technologies over the 21st century. Our approach is to analyze the future energy system under a number of different scenarios that span a wide range of possible future demographic, socio-economic, and technological developments. Scenarios both with, and without, carbon dioxide concentration stabilization policies are considered. We use the comprehensive set of scenarios created for the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (Nakicenovic and Swart 2000). The focus of our analysis will be the cost of electric generation. Cost is particularly important when considering electric generation since the type of generation is, from a practical point of view, largely irrelevant to the end-user. This means that different electricity generation technologies must compete on the basis of price. It is important to note, however, that even a technology that is more expensive than average can contribute to the overall generation mix due to geographical and economic heterogeneity (Clarke and Edmonds 1993). This type of competition is a central assumption of the modeling approach used here. Our analysis suggests that, under conditions of full competition of all available technologies, Space Solar Power at 7 cents per kW-hr could comprise 5-10% of global electric generation by the end of the century, with a global total generation of 10,000 TW-hr. The generation share of Space Solar Power is limited due to competition with lower-cost nuclear, biomass, and terrestrial solar PV and wind. The imposition of a carbon constraint does not significantly increase the total amount of power generated by Space Solar Power in cases where a full range of advanced electric generation technologies are also available. Potential constraints on the availability of these other electric generation options can increase the amount of

Experimental investigation of solar powered diaphragm and helical pumps

Science.gov (United States)

For several years, many types of solar powered water pumping systems were evaluated, and in this paper, diaphragm and helical solar photovoltaic (PV) powered water pumping systems are discussed. Data were collected on diaphragm and helical pumps which were powered by different solar PV arrays at mul...

Consumer attitudes towards domestic solar power systems

Energy Technology Data Exchange (ETDEWEB)

Faiers, Adam [Institute of Water and Environment, Cranfield University at Silsoe, Silsoe, Bedfordshire, MK45 4DT (United Kingdom)]. E-mail: a.j.faiers.so2@cranfield.ac.uk; Neame, Charles [Institute of Water and Environment, Cranfield University at Silsoe, Silsoe, Bedfordshire, MK45 4DT (United Kingdom)]. E-mail: c.neame@cranfield.ac.uk

2006-09-15

The success of the UK policy to reduce carbon emissions is partly dependent on the ability to persuade householders to become more energy efficient, and to encourage installation of domestic solar systems. Solar power is an innovation in the UK but the current policy of stimulating the market with grants is not resulting in widespread adoption. This case study, using householders in central England, investigates householder attitudes towards characteristics of solar systems and identifies some of the barriers to adoption. The study utilises Diffusion of Innovations theory to identify attitudes towards system attributes, and isolates the characteristics that are preventing a pragmatic 'early majority' from adopting the technology. A group of 'early adopters', and a group of assumed 'early majority' adopters of solar power were surveyed and the results show that overall, although the 'early majority' demonstrate a positive perception of the environmental characteristics of solar power, its financial, economic and aesthetic characteristics are limiting adoption. Differences exist between the two groups showing support for the concept of a 'chasm' between adopter categories after Moore (Crossing the Chasm: Marketing and Selling High-tech Products to Mainstream Customers, second ed. Harper Perennial, New York). However, if consumers cannot identify the relative advantage of solar power over their current sources of power, which is supplied readily and cheaply through a mains system, it is unlikely that adoption will follow. Recommendations concerning the marketing and development of solar products are identified.

Solar thermal power meeting - Proceedings

International Nuclear Information System (INIS)

2011-07-01

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

A fresh look at space solar power

International Nuclear Information System (INIS)

Mankins, J.C.

1996-01-01

Studies of systems to provide solar power from space for terrestrial use defined very large, geostationary Earth orbit (GEO) satellite concepts that--given massive initial government investments and extremely low cost space launch--might have led to power production at costs only somewhat higher than expected commercial prices. These studies of space solar power (SSP) succeeded in establishing technical feasibility. Shortly after the completion of the 1970s study, however, US funding came to an abrupt and seemingly permanent halt--in part because projected costs for the reference system were staggering: well in excess of $100B to achieve the first commercial kilowatt-hour of power. SSP has seen sporadic study and limited experimentation during the past decade (e.g., in Japan). Still, no existing SSP concept has engendered private development. New technologies now make possible concepts and approaches that suggest that SSP economic feasibility may be achievable early in the next century. In 1995, NASA's Advanced Concepts Office initiated a study taking a fresh look at innovative concepts for SSP that differ markedly from previously examined concepts, addressing innovative system architectures, markets and technologies that could radically reduce initial and operational costs. This paper will explore the issues associated with SSP and will summarize the results to date of NASA's recent fresh look at this important and increasingly timely field of space applications

Concentrated solar thermal power - Now

Energy Technology Data Exchange (ETDEWEB)

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

2005-09-15

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

An automated tool for solar power systems

International Nuclear Information System (INIS)

Natsheh, E.M.; Natsheh, A.R.; Albarbar, AH

2014-01-01

In this paper a novel model of smart grid-connected solar power system is developed. The model is implemented using MatLab/SIMULINK software package. Artificial neural network (ANN) algorithm is used for maximizing the generated power based on maximum power point tracker (MPPT) implementation. The dynamic behavior of the proposed model is examined under different operating conditions. Solar irradiance, and temperature data are gathered from a grid connected, 28.8 kW solar power system located in central Manchester. The developed system and its control strategy exhibit excellent performance with tracking efficiency exceed 94.5%. The proposed model and its control strategy offer a proper tool for smart grid performance optimization. (author)

Proton irradiation effects of amorphous silicon solar cell for solar power satellite

Energy Technology Data Exchange (ETDEWEB)

Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

1997-03-01

Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

Large Scale Solar Heating

DEFF Research Database (Denmark)

Heller, Alfred

2001-01-01

The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out...... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....

Design and implementation of a microcontroller-based maximum power point tracking fuzzy solar-charge controller

Energy Technology Data Exchange (ETDEWEB)

Qazalbash, A.A.; Iqbal, T.; Shafiq, M.Z. [National Univ. of Sciences and Technology, Rawalpindi (Pakistan). Dept. of Electrical Engineering

2007-07-01

Photovoltaic (PV) solar arrays are particularly useful for electrical power generation in remote, off-grid areas in developing countries. However, PV arrays offer a small power to area ratio, resulting in the need for more PV arrays which increases the cost of the system. In order to improve the profitability of PV arrays, the power extraction from available PV array systems must be maximized. This paper presented an analysis, modeling and implementation of an efficient solar charge controller. It was shown that the maximum power of a photovoltaic system depends largely on temperature and insolation. A perturb and observe algorithm was used for maximum power point tracking (MPPT). MPPT maximizes the efficiency of a solar PV system. A solar charge controller determines the optimal values of output current and voltage of converters to maximize power output for battery charging. In order to improve performance and implement the perturb and observe algorithm, the authors designed a fuzzy rule-based system in which a solar charge controller worked with a PWM controlled DC-DC converter for battery charging. The system was implemented on a low-cost PIC microcontroller. Results were better than conventional techniques in power efficiency. Swift maximum power point tracking was obtained. 13 refs., 1 tab., 11 figs.

Energy parameter estimation in solar powered wireless sensor networks

KAUST Repository

Mousa, Mustafa; Claudel, Christian G.

2014-01-01

The operation of solar powered wireless sensor networks is associated with numerous challenges. One of the main challenges is the high variability of solar power input and battery capacity, due to factors such as weather, humidity, dust and temperature. In this article, we propose a set of tools that can be implemented onboard high power wireless sensor networks to estimate the battery condition and capacity as well as solar power availability. These parameters are very important to optimize sensing and communications operations and maximize the reliability of the complete system. Experimental results show that the performance of typical Lithium Ion batteries severely degrades outdoors in a matter of weeks or months, and that the availability of solar energy in an urban solar powered wireless sensor network is highly variable, which underlines the need for such power and energy estimation algorithms.

Energy parameter estimation in solar powered wireless sensor networks

KAUST Repository

Mousa, Mustafa

2014-02-24

The operation of solar powered wireless sensor networks is associated with numerous challenges. One of the main challenges is the high variability of solar power input and battery capacity, due to factors such as weather, humidity, dust and temperature. In this article, we propose a set of tools that can be implemented onboard high power wireless sensor networks to estimate the battery condition and capacity as well as solar power availability. These parameters are very important to optimize sensing and communications operations and maximize the reliability of the complete system. Experimental results show that the performance of typical Lithium Ion batteries severely degrades outdoors in a matter of weeks or months, and that the availability of solar energy in an urban solar powered wireless sensor network is highly variable, which underlines the need for such power and energy estimation algorithms.

A LARGE-SCALE SEARCH FOR EVIDENCE OF QUASI-PERIODIC PULSATIONS IN SOLAR FLARES

Energy Technology Data Exchange (ETDEWEB)

Inglis, A. R.; Ireland, J.; Dennis, B. R. [Solar Physics Laboratory, Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hayes, L; Gallagher, P. [Trinity College Dublin, Dublin (Ireland)

2016-12-20

The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1–300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1–8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi /Gamma-ray Burst Monitor (GBM) 15–25 keV X-ray data for each of these flares associated with a Fermi /GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that ∼30% of GOES events and ∼8% of Fermi /GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic timescale of ∼5–30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

A Large-Scale Search for Evidence of Quasi-Periodic Pulsations in Solar Flares

Science.gov (United States)

Inglis, A. R.; Ireland, J.; Dennis, B. R..; Hayes, L.; Gallagher, P.

2016-01-01

The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 18 soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi/Gamma-ray Burst Monitor (GBM) 1525 keV X-ray data for each of these flares associated with a Fermi/GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that approx. 30% of GOES events and approx. 8% of Fermi/GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic time-scale of approx. 5-30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic time-scales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

A LARGE-SCALE SEARCH FOR EVIDENCE OF QUASI-PERIODIC PULSATIONS IN SOLAR FLARES

International Nuclear Information System (INIS)

Inglis, A. R.; Ireland, J.; Dennis, B. R.; Hayes, L; Gallagher, P.

2016-01-01

The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1–300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1–8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi /Gamma-ray Burst Monitor (GBM) 15–25 keV X-ray data for each of these flares associated with a Fermi /GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that ∼30% of GOES events and ∼8% of Fermi /GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic timescale of ∼5–30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

Aesthetic impact assessment of solar power plants. An objective and a subjective approach

Energy Technology Data Exchange (ETDEWEB)

Torres-Sibille, Ana del Carmen; Cloquell-Ballester, Vicente-Agustin; Cloquell-Ballester, Victor-Andres; Artacho Ramirez, Miguel Angel [Dpto. Proyectos de Ingenieria, Valencia University of Technology, Camino de Vera s/n, 46022 Valencia (Spain)

2009-06-15

Solar energy for the production of electric energy is one source of renewable energy which is experiencing most development in recent years. In countries with high solar radiation indices, as is the case of Spain, expectations of installation of large solar power plants are increasing. Most solar power plants are located in rural environments, where the landscape has remained practically unaltered ever since extensive agriculture was introduced. Because of this, one of the most significant environmental impacts of this type of installation is the visual impact derived from the alteration of the landscape. In this work, an indicator is proposed for the quantification of the objective aesthetic impact, based on four criteria: visibility, colour, fractality and concurrence between fixed and mobile panels. The relative importance of each variable and the corresponding value functions are calculated using expert contribution. A study of the subjective aesthetic impact is then carried out using the semantic differential method, to obtain the perception of a sample of individuals of the initial landscapes and of the landscapes altered through the installation of a solar power plant. The indicator and the study of public perception are applied to five real solar power plants, to test their reliability. Subsequently, a different group of individuals is used to determine preferences between the five solar power plants. The study proves that the combined use of objective indicator and subjective study, faithfully explains user preferences corresponding to the combined comparisons of the five cases. It is concluded that the tools proposed for the evaluation of the aesthetic impact of solar power plants are useful for the selection of optimal plant location and most adequate use of panel technology, to minimise aesthetic impact. (author)

Market to facilitate wind and solar energy integration in the bulk power supply

Energy Technology Data Exchange (ETDEWEB)

Milligan, Michael [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Soeder, Lennart [Royal Inst. of Tech., Stockholm (Sweden); Holttinen, Hannele [VTT Energy, Espoo (Finland); Clark, Charlton [U.S. Department of Energy Washington, DC (United States); Pineda, Ivan [European Wind Energy Association, Brussels (Belgium); Collaboration: IEA Task 25 collaboration

2012-07-01

Wind and solar power will give rise to challenges in electricity markets regarding flexibility, capacity adequacy, and the participation of wind and solar generators to markets. Large amounts of wind power will have impacts on bulk power system markets and electricity prices. If the markets respond to increased wind power by increasing investments in low-capital-cost/high-marginal-cost power, the average price may remain in the same range. However, the experiences so far from Denmark, Germany, Spain, and Ireland are that the average market prices decreased because of wind power. This reduction in price may result in additional revenue insufficiency, which may be corrected with a capacity market; however, capacity markets are difficult to design. Further, the flexibility attributes of the capacity need to be considered. Markets facilitating wind and solar integration will include possibilities for trading close to delivery (either by shorter gate closure times or intraday markets). Time steps chosen for markets can enable more flexibility to be assessed. Experience from 5- and 10-minute markets has been encouraging. (orig.)

Overview of NASA's Space Solar Power Technology Advanced Research and Development Program

Science.gov (United States)

Howell, Joe; Mankins, John C.; Davis, N. Jan (Technical Monitor)

2001-01-01

Large solar power satellite (SPS) systems that might provide base load power into terrestrial markets were examined extensively in the 1970s by the US Department of Energy (DOE) and the National Aeronautics and Space Administration (NASA). Following a hiatus of about 15 years, the subject of space solar power (SSP) was reexamined by NASA from 1995-1997 in the 'fresh look' study, and during 1998 in an SSP 'concept definition study', and during 1999-2000 in the SSP Exploratory Research and Technology (SERT) program. As a result of these efforts, during 2001, NASA has initiated the SSP Technology Advanced Research and Development (STAR-Dev) program based on informed decisions. The goal of the STAR-Dev program is to conduct preliminary strategic technology research and development to enable large, multi-megawatt to gigawatt-class space solar power (SSP) systems and wireless power transmission (WPT) for government missions and commercial markets (in-space and terrestrial). Specific objectives include: (1) Release a NASA Research Announcement (NRA) for SSP Projects; (2) Conduct systems studies; (3) Develop Component Technologies; (4) Develop Ground and Flight demonstration systems; and (5) Assess and/or Initiate Partnerships. Accomplishing these objectives will allow informed future decisions regarding further SSP and related research and development investments by both NASA management and prospective external partners. In particular, accomplishing these objectives will also guide further definition of SSP and related technology roadmaps including performance objectives, resources and schedules; including 'multi-purpose' applications (commercial, science, and other government).

Solar power in South Africa; Anpfiff in Suedafrika

Energy Technology Data Exchange (ETDEWEB)

Ristau, Oliver

2010-07-01

Excellent reimbursement regulations for solar power should be enough to promote photovoltaic energy conversion in South Africa. However, public utilities are not obliged to buy solar power, and the connection of private solar systems to the public grid is a matter for negotiation. Many private investors therefore decide to instal autonomous systems. (orig.)

Deployable Propulsion, Power and Communication Systems for Solar System Exploration

Science.gov (United States)

Johnson, Les; Carr, John A.; Boyd, Darren

2017-01-01

NASA is developing thin-film based, deployable propulsion, power, and communication systems for small spacecraft that could provide a revolutionary new capability allowing small spacecraft exploration of the solar system. By leveraging recent advancements in thin films, photovoltaics, and miniaturized electronics, new mission-level capabilities will be enabled aboard lower-cost small spacecraft instead of their more expensive, traditional counterparts, enabling a new generation of frequent, inexpensive deep space missions. Specifically, thin-film technologies are allowing the development and use of solar sails for propulsion, small, lightweight photovoltaics for power, and omnidirectional antennas for communication. Like their name implies, solar sails 'sail' by reflecting sunlight from a large, lightweight reflective material that resembles the sails of 17th and 18th century ships and modern sloops. Instead of wind, the sail and the ship derive their thrust by reflecting solar photons. Solar sail technology has been discussed in the literature for quite some time, but it is only since 2010 that sails have been proven to work in space. Thin-film photovoltaics are revolutionizing the terrestrial power generation market and have been found to be suitable for medium-term use in the space environment. When mounted on the thin-film substrate, these photovoltaics can be packaged into very small volumes and used to generate significant power for small spacecraft. Finally, embedded antennas are being developed that can be adhered to thin-film substrates to provide lightweight, omnidirectional UHF and X-band coverage, increasing bandwidth or effective communication ranges for small spacecraft. Taken together, they may enable a host of new deep space destinations to be reached by a generation of spacecraft smaller and more capable than ever before.

Stillwater Hybrid Geo-Solar Power Plant Optimization Analyses

Energy Technology Data Exchange (ETDEWEB)

Wendt, Daniel S.; Mines, Gregory L.; Turchi, Craig S.; Zhu, Guangdong; Cohan, Sander; Angelini, Lorenzo; Bizzarri, Fabrizio; Consoli, Daniele; De Marzo, Alessio

2015-09-02

The Stillwater Power Plant is the first hybrid plant in the world able to bring together a medium-enthalpy geothermal unit with solar thermal and solar photovoltaic systems. Solar field and power plant models have been developed to predict the performance of the Stillwater geothermal / solar-thermal hybrid power plant. The models have been validated using operational data from the Stillwater plant. A preliminary effort to optimize performance of the Stillwater hybrid plant using optical characterization of the solar field has been completed. The Stillwater solar field optical characterization involved measurement of mirror reflectance, mirror slope error, and receiver position error. The measurements indicate that the solar field may generate 9% less energy than the design value if an appropriate tracking offset is not employed. A perfect tracking offset algorithm may be able to boost the solar field performance by about 15%. The validated Stillwater hybrid plant models were used to evaluate hybrid plant operating strategies including turbine IGV position optimization, ACC fan speed and turbine IGV position optimization, turbine inlet entropy control using optimization of multiple process variables, and mixed working fluid substitution. The hybrid plant models predict that each of these operating strategies could increase net power generation relative to the baseline Stillwater hybrid plant operations.

Elite silicon and solar power

International Nuclear Information System (INIS)

Yasamanov, N.A.

2000-01-01

The article is of popular character, the following issues being considered: conversion of solar energy into electric one, solar batteries in space and on the Earth, growing of silicon large-size crystals, source material problems relating to silicon monocrystals production, outlooks of solar silicon batteries production [ru

Review of avian mortality studies at concentrating solar power plants

Science.gov (United States)

Ho, Clifford K.

2016-05-01

This paper reviews past and current avian mortality studies at concentrating solar power (CSP) plants and facilities including Solar One in California, the Solar Energy Development Center in Israel, Ivanpah Solar Electric Generating System in California, Crescent Dunes in Nevada, and Gemasolar in Spain. Findings indicate that the leading causes of bird deaths at CSP plants are from collisions (primarily with reflective surfaces; i.e., heliostats) and singeing caused by concentrated solar flux. Safe irradiance levels for birds have been reported to range between 4 and 50 kW/m2. Above these levels, singeing and irreversible damage to the feathers can occur. Despite observations of large numbers of "streamers" in concentrated flux regions and reports that suggest these streamers indicate complete vaporization of birds, analyses in this paper show that complete vaporization of birds is highly improbable, and the observed streamers are likely due to insects flying into the concentrated flux. The levelized avian mortality rate during the first year of operation at Ivanpah was estimated to be 0.7 - 3.5 fatalities per GWh, which is less than the levelized avian mortality reported for fossil fuel plants but greater than that for nuclear and wind power plants. Mitigation measures include acoustic, visual, tactile, and chemosensory deterrents to keep birds away from the plant, and heliostat aiming strategies that reduce the solar flux during standby.

Solar Thermal Power.

Science.gov (United States)

McDaniels, David K.

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

Solar dynamic power system definition study

Science.gov (United States)

Wallin, Wayne E.; Friefeld, Jerry M.

1988-01-01

The solar dynamic power system design and analysis study compared Brayton, alkali-metal Rankine, and free-piston Stirling cycles with silicon planar and GaAs concentrator photovoltaic power systems for application to missions beyond the Phase 2 Space Station level of technology for all power systems. Conceptual designs for Brayton and Stirling power systems were developed for 35 kWe and 7 kWe power levels. All power systems were designed for 7-year end-of-life conditions in low Earth orbit. LiF was selected for thermal energy storage for the solar dynamic systems. Results indicate that the Stirling cycle systems have the highest performance (lowest weight and area) followed by the Brayton cycle, with photovoltaic systems considerably lower in performance. For example, based on the performance assumptions used, the planar silicon power system weight was 55 to 75 percent higher than for the Stirling system. A technology program was developed to address areas wherein significant performance improvements could be realized relative to the current state-of-the-art as represented by Space Station. In addition, a preliminary evaluation of hardenability potential found that solar dynamic systems can be hardened beyond the hardness inherent in the conceptual designs of this study.

Electrostatic protection of the solar power satellite and rectenna. Part 1: Protection of the solar power satellite

Science.gov (United States)

1980-01-01

Several features of the interactions of the Solar Power Satellite (SPS) with its space environment are examined theoretically. The voltages produced at various surfaces due to space plasmas and the plasma leakage currents through the kapton and sapphire solar cell blankets are calculated. At geosynchronous orbit, this parasitic power loss is only 0.7%, and is easily compensated by oversizing. At low Earth orbit, the power loss is potentially much larger (3%), and anomalous arcing is expected for the EOTV high voltage negative surfaces. Preliminary results of a three dimensional self consistent plasma and electric field computer program are presented, confirming the validity of the predictions made from the one dimensional models. Lastly, magnetic shielding of the satellite is considered to reduce the power drain and to protect the solar cells from energetic electron and plasma ion bombardment. It is concluded that minor modifications can allow the SPS to operate safely and efficiently in its space environment. Subsequent design changes will substantially alter the basic conclusions.

Feature Selection and ANN Solar Power Prediction

OpenAIRE

O’Leary, Daniel; Kubby, Joel

2017-01-01

A novel method of solar power forecasting for individuals and small businesses is developed in this paper based on machine learning, image processing, and acoustic classification techniques. Increases in the production of solar power at the consumer level require automated forecasting systems to minimize loss, cost, and environmental impact for homes and businesses that produce and consume power (prosumers). These new participants in the energy market, prosumers, require new artificial neural...

Location Study of Solar Thermal Power Plant in the State of Pernambuco Using Geoprocessing Technologies and Multiple-Criteria Analysis

Directory of Open Access Journals (Sweden)

Verônica Wilma B. Azevêdo

2017-07-01

Full Text Available Solar Thermal Technology for the generation of electricity in large scale has been a reality in the world since the 1980s, when the first large-sized solar plants in the United States were introduced. Brazil presents great potential for the development of large-scale projects, although it is noted that the main barriers for the insertion of this technology in Brazilian market are the lack of incentives and goals and associated costs. In a way to contribute to the insertion of solar thermal technology in Brazil, this paper presents a macro-spatial approach, based on the use of Multiple-Criteria Decision Analysis and Geoprocessing, for the location of solar thermal power plants. The applied methodology for Pernambuco, located in the Northeast Region of Brazil, considered the implantation of parabolic trough solar power plant of 80 MW, operating only in solar mode, without heat storage. Based on performed analysis, it was confirmed that Pernambuco presents great potential for the installation of solar power plants, especially in the backlands of Pernambuco. Performed validations in the model demonstrate that the methodology attended the objective once the consistence between the assigned weights to the thematic layers, individually, and the final Map of site suitability were evidenced.

Solar powered Stirling engine

Energy Technology Data Exchange (ETDEWEB)

Meijer, R.J.

1987-11-24

In a solar dish module which comprises a dish which receives incident solar rays and reflects them to a focus at which is located the combination of a receiver and a heat engine organized and arranged so that the heat energy of the reflected solar rays collected at the receiver powers the engine, and wherein the receiver and heat engine are supported from the dish by a framework, the improvement is described which comprises journal means for journaling at least the engine on the framework to maintain certain predetermined spatial orientation for the engine in relation to the direction of gravity irrespective of spatial orientation of the dish.

Fuzzy Controller for a Voltage-Regulated Solar-Powered MPPT System for Hybrid Power System Applications

Directory of Open Access Journals (Sweden)

Jaw-Kuen Shiau

2015-04-01

Full Text Available This paper presents the design of a fuzzy-logic-based voltage-regulated solar power maximum power point tracking (MPPT system for applications involving hybrid power systems. The system contains a solar power system and battery as the primary and secondary power sources, respectively. The solar system alone supplies power to the electric motor and maintains the output voltage at a predetermined level when it has sufficient power. When the solar power is insufficient, the solar system is operated at its maximum power point (MPP and the battery is engaged to compensate for the insufficiency. First, a variant of the incremental conductance MPP condition was established. Under the MPP condition, the voltage-regulated MPPT system was formulated as a feedback control system, where the MPP condition and voltage regulation requirements were used as the system inputs. Next, a fuzzy controller was developed to perform the voltage-regulated MPPT function for the hybrid power system. A simulation model based on Matrix laboratory (MATLAB/SIMULINK (a block diagram environment for multi-domain simulation and model-based design and a piecewise linear electric circuit simulation (PLECS tool for controlling the dc motor velocity was developed to verify the voltage-regulated solar power MPPT system.

Concentrating Solar Power Program Review 2013 (Book) (Revised)

Energy Technology Data Exchange (ETDEWEB)

2013-06-01

This U.S. Department of Energy (DOE) Concentrating Solar Power Program Review Meeting booklet will be provided to attendees at the Concentrating Solar Power Review Meeting in Phoenix, Arizona on April 23-25, 2013.

Fiscal 1974 Sunshine Project result report. Research on solar energy utilization systems (solar heat power generation); 1974 nendo taiyo energy riyo system chosa kenkyu seika hokokusho. Taiyonetsu hatsuden

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-03-01

This report summarizes the fiscal 1974 research result on solar heat power generation. The following are promising as solar heat power plant sites in Japan: Large-scale sites such as the foot of volcanos, riverbed, railway site and road, medium-scale sites such as isolated island, saltpan site and industrial park, and small-scale sites such as factory site, factory roof floor, housing complex, warehouse and school. Based on the primary concept design of both curved reflector type and tower type 1,000kW class solar heat power plants, various requirements were clarified roughly. It was clarified that food, fiber and non-ferrous metal factories can cover 80-90% of their thermal energy requirements with high- temperature solar heat, while factories related to food and fiber can cover even nearly 100% of their electric power requirements with solar heat. Study was also made on specifications of a solar simulator as common use facility necessary for characteristic evaluation of equipment and materials for solar heat power generation systems. (NEDO)

Leasing solar power instead of buying it; Solarpaechter statt Stromkaeufer

Energy Technology Data Exchange (ETDEWEB)

Oppen, Margarete von [Rechtsanwaltssozietaet Geiser und von Oppen, Berlin (Germany)

2012-11-01

Owners of PV systems wo let their tenants or neighbours use their solar power may make bigger profits than from reimbursement for power supply to the public grid. The contribution relates solar power price components to solar module types.

Solar photovoltaic power for water desalination

Energy Technology Data Exchange (ETDEWEB)

Wood, J. R.; Crutcher, J. L.; Norbedo, A. J.; Cummings, A. B.

1980-07-01

There is a considerable global need for systems which can meet the drinking water requirements of small communities (7000 people or less) from brackish water or from seawater. Solar photovoltaic panels are an ideal source of power for the purpose, primarily because they produce electricity, which can be used to power a membrane type desalting unit, i.e., either a reverse osmosis plant or an electrodialysis unit. In addition, electricity is most convenient for feedwater pumping. This paper addresses considerations which arise in the design and construction of a complete solar powered water desalination system which requires no supply of fuel nor any form of backup power (grid connection or engine generator).

Solar Powered Heat Storage for Injera Baking

OpenAIRE

Tesfay, Asfafaw H; Kahsay, Mulu Bayray; Nydal, Ole Jørgen

2014-01-01

Ethiopia with a population of about 85 million meets 96% of its energy needs with bio-mass, charcoal, wood, animal dung and plant residues. More than 50% of this energy goes entirely on baking Injera. Injera the national food of the country demands 180-220 °C to be well cooked. In this article; Injera baking with solar energy on off-focus system, status of electric powered stove and the potential for solar powered stoves is discussed. The research and development of solar thermal for househol...

Solar thermal power plants simulation using the TRNSYS software

Energy Technology Data Exchange (ETDEWEB)

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

1999-03-01

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

Implications of longitude and latitude on the size of solar-powered UAV

International Nuclear Information System (INIS)

Rajendran, Parvathy; Smith, Howard

2015-01-01

Highlights: • We studied solar irradiance and daylight implication on solar-powered UAV design. • We explored for perpetual UAV flight for 12 cities around the world. • All year round solar-powered UAV operation possible for cities near equatorial line. • Cities in latitudes of ±35° are the optimal for solar-powered UAV. • Longitudinal coordinates and elevation have a minor effect on UAV design. - Abstract: The implication of solar irradiance and daylight duration on the design of a small solar-powered unmanned aerial vehicle (UAV) that is capable of operating perpetually in various cities around the world was investigated. Solar data in 2013 on 12 cities distributed around the world was collected. The effects of the available solar irradiance and daylight of the city on the maximum take-off weight and wing span of a small solar-powered UAV were studied. The analysis indicates that daylight duration is as important as the available solar irradiance to the performance of the solar-powered UAV. Longitudinal coordinates and elevation have a minor effect on the estimation of daylight duration. Areas considerably high in solar irradiance and daylight duration are more conducive to the effective performance of solar-powered UAVs than other areas. Therefore, cities closer to the equator have an advantage in utilizing solar-powered UAVs; where smaller and lighter solar-powered UAV can be designed

Solar powered oxygen systems in remote health centers in Papua New Guinea: a large scale implementation effectiveness trial.

Science.gov (United States)

Duke, Trevor; Hwaihwanje, Ilomo; Kaupa, Magdalynn; Karubi, Jonah; Panauwe, Doreen; Sa'avu, Martin; Pulsan, Francis; Prasad, Peter; Maru, Freddy; Tenambo, Henry; Kwaramb, Ambrose; Neal, Eleanor; Graham, Hamish; Izadnegahdar, Rasa

2017-06-01

Pneumonia is the largest cause of child deaths in Papua New Guinea (PNG), and hypoxaemia is the major complication causing death in childhood pneumonia, and hypoxaemia is a major factor in deaths from many other common conditions, including bronchiolitis, asthma, sepsis, malaria, trauma, perinatal problems, and obstetric emergencies. A reliable source of oxygen therapy can reduce mortality from pneumonia by up to 35%. However, in low and middle income countries throughout the world, improved oxygen systems have not been implemented at large scale in remote, difficult to access health care settings, and oxygen is often unavailable at smaller rural hospitals or district health centers which serve as the first point of referral for childhood illnesses. These hospitals are hampered by lack of reliable power, staff training and other basic services. We report the methodology of a large implementation effectiveness trial involving sustainable and renewable oxygen and power systems in 36 health facilities in remote rural areas of PNG. The methodology is a before-and after evaluation involving continuous quality improvement, and a health systems approach. We describe this model of implementation as the considerations and steps involved have wider implications in health systems in other countries. The implementation steps include: defining the criteria for where such an intervention is appropriate, assessment of power supplies and power requirements, the optimal design of a solar power system, specifications for oxygen concentrators and other oxygen equipment that will function in remote environments, installation logistics in remote settings, the role of oxygen analyzers in monitoring oxygen concentrator performance, the engineering capacity required to sustain a program at scale, clinical guidelines and training on oxygen equipment and the treatment of children with severe respiratory infection and other critical illnesses, program costs, and measurement of processes and

Power Flow Simulations of a More Renewable California Grid Utilizing Wind and Solar Insolation Forecasting

Science.gov (United States)

Hart, E. K.; Jacobson, M. Z.; Dvorak, M. J.

2008-12-01

Time series power flow analyses of the California electricity grid are performed with extensive addition of intermittent renewable power. The study focuses on the effects of replacing non-renewable and imported (out-of-state) electricity with wind and solar power on the reliability of the transmission grid. Simulations are performed for specific days chosen throughout the year to capture seasonal fluctuations in load, wind, and insolation. Wind farm expansions and new wind farms are proposed based on regional wind resources and time-dependent wind power output is calculated using a meteorological model and the power curves of specific wind turbines. Solar power is incorporated both as centralized and distributed generation. Concentrating solar thermal plants are modeled using local insolation data and the efficiencies of pre-existing plants. Distributed generation from rooftop PV systems is included using regional insolation data, efficiencies of common PV systems, and census data. The additional power output of these technologies offsets power from large natural gas plants and is balanced for the purposes of load matching largely with hydroelectric power and by curtailment when necessary. A quantitative analysis of the effects of this significant shift in the electricity portfolio of the state of California on power availability and transmission line congestion, using a transmission load-flow model, is presented. A sensitivity analysis is also performed to determine the effects of forecasting errors in wind and insolation on load-matching and transmission line congestion.

Study of solar array switching power management technology for space power system

Science.gov (United States)

Cassinelli, J. E.

1982-01-01

This report documents work performed on the Solar Array Switching Power Management Study. Mission characteristics for three missions were defined to the depth necessary to determine their power management requirements. Solar array switching concepts which could satisfy the mission requirements were identified. The switching concepts were compared with a conventional buck regulator system for cost, weight and volume, reliability, efficiency and thermal control. Solar array switching provided significant advantages in all areas of comparison for the reviewed missions.

Quantifying the Impacts of Large Scale Integration of Renewables in Indian Power Sector

Science.gov (United States)

Kumar, P.; Mishra, T.; Banerjee, R.

2017-12-01

India's power sector is responsible for nearly 37 percent of India's greenhouse gas emissions. For a fast emerging economy like India whose population and energy consumption are poised to rise rapidly in the coming decades, renewable energy can play a vital role in decarbonizing power sector. In this context, India has targeted 33-35 percent emission intensity reduction (with respect to 2005 levels) along with large scale renewable energy targets (100GW solar, 60GW wind, and 10GW biomass energy by 2022) in INDCs submitted at Paris agreement. But large scale integration of renewable energy is a complex process which faces a number of problems like capital intensiveness, matching intermittent loads with least storage capacity and reliability. In this context, this study attempts to assess the technical feasibility of integrating renewables into Indian electricity mix by 2022 and analyze its implications on power sector operations. This study uses TIMES, a bottom up energy optimization model with unit commitment and dispatch features. We model coal and gas fired units discretely with region-wise representation of wind and solar resources. The dispatch features are used for operational analysis of power plant units under ramp rate and minimum generation constraints. The study analyzes India's electricity sector transition for the year 2022 with three scenarios. The base case scenario (no RE addition) along with INDC scenario (with 100GW solar, 60GW wind, 10GW biomass) and low RE scenario (50GW solar, 30GW wind) have been created to analyze the implications of large scale integration of variable renewable energy. The results provide us insights on trade-offs involved in achieving mitigation targets and investment decisions involved. The study also examines operational reliability and flexibility requirements of the system for integrating renewables.

Generation of large-scale PV scenarios using aggregated power curves

DEFF Research Database (Denmark)

Nuño Martinez, Edgar; Cutululis, Nicolaos Antonio

2017-01-01

The contribution of solar photovoltaic (PV) power to the generation is becoming more relevant in modern power system. Therefore, there is a need to model the variability large-scale PV generation accurately. This paper presents a novel methodology to generate regional PV scenarios based...... on aggregated power curves rather than traditional physical PV conversion models. Our approach is based on hourly mesoscale reanalysis irradiation data and power measurements and do not require additional variables such as ambient temperature or wind speed. It was used to simulate the PV generation...... on the German system between 2012 and 2015 showing high levels of correlation with actual measurements (93.02–97.60%) and small deviations from the expected capacity factors (0.02–1.80%). Therefore, we are confident about the ability of the proposed model to accurately generate realistic large-scale PV...

A Low-Power and Low-Voltage Power Management Strategy for On-Chip Micro Solar Cells

Directory of Open Access Journals (Sweden)

Ismail Cevik

2015-01-01

Full Text Available Fundamental characteristics of on-chip micro solar cell (MSC structures were investigated in this study. Several MSC structures using different layers in three different CMOS processes were designed and fabricated. Effects of PN junction structure and process technology on solar cell performance were measured. Parameters for low-power and low-voltage implementation of power management strategy and boost converter based circuits utilizing fractional voltage maximum power point tracking (FVMPPT algorithm were determined. The FVMPPT algorithm works based on the fraction between the maximum power point operation voltage and the open circuit voltage of the solar cell structure. This ratio is typically between 0.72 and 0.78 for commercially available poly crystalline silicon solar cells that produce several watts of power under typical daylight illumination. Measurements showed that the fractional voltage ratio is much higher and fairly constant between 0.82 and 0.85 for on-chip mono crystalline silicon micro solar cell structures that produce micro watts of power. Mono crystalline silicon solar cell structures were observed to result in better power fill factor (PFF that is higher than 74% indicating a higher energy harvesting efficiency.

Modern prospects of development of branch of solar power

Science.gov (United States)

Luchkina, Veronika

2017-10-01

Advantages of solar energy for modern companies are evident already. Article describes mechanism of the solar electricity generation. Process of production of solar modules with appliance of the modern technologies of sun energy production. The branch of solar energy “green energy” become advanced in Russia and has a stable demand. Classification of investments on the different stages of construction projects of solar power plants and calculation of their economic efficiency. Studying of introduction of these technologies allows to estimate the modern prospects of development of branch of solar power.

Assessing the potential role of concentrated solar power (CSP) for the northeast power system of Brazil using a detailed power system model

International Nuclear Information System (INIS)

Fichter, Tobias; Soria, Rafael; Szklo, Alexandre; Schaeffer, Roberto; Lucena, Andre F.P.

2017-01-01

One of the technologies that stand out as an alternative to provide additional flexibility to power systems with large penetration of variable renewable energy (VRE), especially for regions with high direct normal irradiation (DNI), is concentrated solar power (CSP) plants coupled to thermal energy storage (TES) and back-up (BUS) systems. Brazil can develop this technology domestically, especially in its Northeast region, where most of VRE capacity is being deployed and where lies most of the CSP potential of the country. This work applies the Capacity Expansion Model REMix-CEM, which allows considering dispatch constraints of thermal power plants in long-term capacity expansion optimization. REMix-CEM calculates the optimal CSP plant configuration and its dispatch strategy from a central planning perspective. Results showed that the hybridization of CSP plants with jurema-preta biomass (CSP-BIO) becomes a least-cost option for Brazil by 2040. CSP-BIO contributes to the Northeast power system by regularizing the energy imbalance that results from the large-scale VRE expansion along with conventional inflexible power plants. CSP-BIO plants are able to increase frequency response and operational reserve services and can provide the required additional flexibility that the Northeast power system of Brazil will require into the future. - Highlights: • Concentrating solar power (CSP) plants provide flexibility to power systems. • CSP configuration is optimized endogenously during capacity expansion optimization. • CSP hybridized with biomass supports grid-integration of variable renewable energy. • CSP become the least-cost option for the Northeast power system of Brazil by 2040.

Solar dynamic power module design

Science.gov (United States)

Secunde, Richard R.; Labus, Thomas L.; Lovely, Ronald G.

1989-01-01

Studies have shown that the use of solar dynamic (SD) power for the growth areas of the Space Station Freedom program will result in life cycle cost savings when compared to power supplied by photovoltaic sources. In the SD power module, a concentrator collects and focuses solar energy into a heat receiver which has integral thermal energy storage. A Power Conversion Unit (PCU) based on the closed Brayton cycle removes thermal energy from the receiver and converts that energy to electrical energy. Since the closed Brayton cycle is a single phase gas cycle, the conversion hardware (heat exchangers, turbine, compressor, etc.) can be designed for operation in low earth orbit, and tested with confidence in test facilities on earth before launch into space. The concentrator subassemblies will be aligned and the receiver/PCU/radiator combination completely assembled and charged with gas and cooling liquid on earth before launch to, and assembly on, orbit.

Hybrid solar and hydro-power for Austria

Energy Technology Data Exchange (ETDEWEB)

Weyss, N

1978-02-01

It is proposed that integrating solar powerplants into the Austrian electricity networks could cost less than conventional thermal plants, and provide a high degree of independence to the country. The following aspects are discussed; the seasonal distribution of sunshine, solar power plants, land requirements, economic feasibility, solar/fossil hybrid operation, integration strategy, Malta-B as a calculating unit, solar-hydraulic baseload throughout the year, concrete requirements, solar-hydraulic possibilities within the next 50 years, cement for solar plants, and energy accounting. (MHR)

Solar power satellites: Commercialization and socio-economic impacts

International Nuclear Information System (INIS)

Storelli, V.

1993-01-01

Commercialization prospects for solar power satellites are assessed with reference to their possible impacts on the viability of the fossil fuel market and on international energy and environmental policies. The technical aspects which are examined include: solar panel sizing in relation to solar cell efficiency; the development of point-contact solar cell technology; the feasibility of the use of lunar materials; microwave transmission from the moon; optimum satellite positioning; the use of robots for in-space satellite assembly; satellite transmitted power for hydrogen production and storage; marketable product estimated development time

Power spectral density and scaling exponent of high frequency global solar radiation sequences

Science.gov (United States)

Calif, Rudy; Schmitt, François G.; Huang, Yongxiang

2013-04-01

The part of the solar power production from photovlotaïcs systems is constantly increasing in the electric grids. Solar energy converter devices such as photovoltaic cells are very sensitive to instantaneous solar radiation fluctuations. Thus rapid variation of solar radiation due to changes in the local meteorological condition can induce large amplitude fluctuations of the produced electrical power and reduce the overall efficiency of the system. When large amount of photovoltaic electricity is send into a weak or small electricity network such as island network, the electric grid security can be in jeopardy due to these power fluctuations. The integration of this energy in the electrical network remains a major challenge, due to the high variability of solar radiation in time and space. To palliate these difficulties, it is essential to identify the characteristic of these fluctuations in order to anticipate the eventuality of power shortage or power surge. The objective of this study is to present an approach based on Empirical Mode Decomposition (EMD) and Hilbert-Huang Transform (HHT) to highlight the scaling properties of global solar irradiance data G(t). The scale of invariance is detected on this dataset using the Empirical Mode Decomposition in association with arbitrary-order Hilbert spectral analysis, a generalization of (HHT) or Hilbert Spectral Analysis (HSA). The first step is the EMD, consists in decomposing the normalized global solar radiation data G'(t) into several Intrinsic Mode Functions (IMF) Ci(t) without giving an a priori basis. Consequently, the normalized original solar radiation sequence G'(t) can be written as a sum of Ci(t) with a residual rn. From all IMF modes, a joint PDF P(f,A) of locally and instantaneous frequency f and amplitude A, is estimated. To characterize the scaling behavior in amplitude-frequency space, an arbitrary-order Hilbert marginal spectrum is defined to: Iq(f) = 0 P (f,A)A dA (1) with q × 0 In case of scale

Deployed Base Solar Power (BRIEFING SLIDES)

Science.gov (United States)

2009-09-01

various time intervals. Data Acquisitions and Components:  FieldPoint  Current, Voltage, and Power Transducers  POA Pyranometers  Solar...Tracking Pyranometer  Weather Station  kWh Meter Parameters being monitored:  Solar Module Temperatures  Ambient Temperature  Wind Speed  Wind

Large-Scale Power Production Potential on U.S. Department of Energy Lands

Energy Technology Data Exchange (ETDEWEB)

Kandt, Alicen J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Elgqvist, Emma M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagne, Douglas A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hillesheim, Michael B. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Walker, H. A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); King, Jeff [Colorado School of Mines, Golden, CO (United States); Boak, Jeremy [Colorado School of Mines, Golden, CO (United States); Washington, Jeremy [Colorado School of Mines, Golden, CO (United States); Sharp, Cory [Colorado School of Mines, Golden, CO (United States)

2017-11-03

This report summarizes the potential for independent power producers to generate large-scale power on U.S. Department of Energy (DOE) lands and export that power into a larger power market, rather than serving on-site DOE loads. The report focuses primarily on the analysis of renewable energy (RE) technologies that are commercially viable at utility scale, including photovoltaics (PV), concentrating solar power (CSP), wind, biomass, landfill gas (LFG), waste to energy (WTE), and geothermal technologies. The report also summarizes the availability of fossil fuel, uranium, or thorium resources at 55 DOE sites.

Developing solar power programs : San Francisco's experience

International Nuclear Information System (INIS)

Schwartz, F.

2006-01-01

This keynote address discussed an array of solar programs initiated in government-owned buildings in San Francisco. The programs were strongly supported by the city's mayor,and the voting public. Known for its fog and varying microclimates, 11 monitoring stations were set up throughout the city to determine viable locations for the successful application of solar technologies. It was observed that 90 per cent of the available sunshine occurred in the central valley, whereas fog along the Pacific shore was problematic. Seven of the monitoring sites showed excellent results. Relationships with various city departments were described, as well as details of study loads, load profiles, electrical systems, roofs and the structural capabilities of the selected government buildings. There was a focus on developing good relations with the local utility. The Moscone Convention Center was selected for the program's flagship installation, a 675 kW solar project which eventually won the US EPA Green Power Award for 2004 and received high press coverage. Cost of the project was $4.2 million. 825,000 kWh solar electricity was generated, along with 4,500,000 kWh electricity saved annually from efficiency measures, resulting in a net reduction of 5,325,000 kWh. Savings on utilities bills for the center were an estimated $1,078,000. A pipeline of solar projects followed, with installations at a sewage treatment plant and a large recycling depot. A program of smaller sites included libraries, schools and health facilities. Details of plans to apply solar technology to a 500 acre redevelopment site in southeast San Francisco with an aging and inadequate electrical infrastructure were described. A model of efficient solar housing for the development was presented, with details of insulation, windows, heating ventilation and air-conditioning (HVAC), water heating, lighting, appliances and a 1.2 kilowatt solar system. Peak demand reductions were also presented. tabs., figs

Solar Pumped Solid State Lasers for Space Solar Power: Experimental Path

Science.gov (United States)

Fork, Richard L.; Carrington, Connie K.; Walker, Wesley W.; Cole, Spencer T.; Green, Jason J. A.; Laycock, Rustin L.

2003-01-01

We outline an experimentally based strategy designed to lead to solar pumped solid state laser oscillators useful for space solar power. Our method involves solar pumping a novel solid state gain element specifically designed to provide efficient conversion of sunlight in space to coherent laser light. Kilowatt and higher average power is sought from each gain element. Multiple such modular gain elements can be used to accumulate total average power of interest for power beaming in space, e.g., 100 kilowatts and more. Where desirable the high average power can also be produced as a train of pulses having high peak power (e.g., greater than 10(exp 10 watts). The modular nature of the basic gain element supports an experimental strategy in which the core technology can be validated by experiments on a single gain element. We propose to do this experimental validation both in terrestrial locations and also on a smaller scale in space. We describe a terrestrial experiment that includes diagnostics and the option of locating the laser beam path in vacuum environment. We describe a space based experiment designed to be compatible with the Japanese Experimental Module (JEM) on the International Space Station (ISS). We anticipate the gain elements will be based on low temperature (approx. 100 degrees Kelvin) operation of high thermal conductivity (k approx. 100 W/cm-K) diamond and sapphire (k approx. 4 W/cm-K). The basic gain element will be formed by sequences of thin alternating layers of diamond and Ti:sapphire with special attention given to the material interfaces. We anticipate this strategy will lead to a particularly simple, robust, and easily maintained low mass modelocked multi-element laser oscillator useful for space solar power.

Lessons learned on solar powered wireless sensor network deployments in urban, desert environments

KAUST Repository

Dehwah, Ahmad H.; Mousa, Mustafa; Claudel, Christian G.

2015-01-01

The successful deployment of a large scale solar powered wireless sensor network in an urban, desert environment is a very complex task. Specific cities of such environments cause a variety of operational problems, ranging from hardware faults

Comparison of the Energy Conversion Efficiency of a Solar Chimney and a Solar PV-Powered Fan for Ventilation Applications

Directory of Open Access Journals (Sweden)

Lubomír Klimeš

2018-04-01

Full Text Available A study into the performance of a solar chimney and a solar photovoltaic (PV-powered fan for ventilation applications was carried out using numerical simulations. The performance of the solar chimney was compared with that of a direct current (DC fan powered by a solar PV panel. The comparison was carried out using the same area of the irradiated surface—the area of the solar absorber plate in the case of the solar chimney and the area of the solar panel in the case of the photovoltaic-powered fan. The two studied cases were compared under various solar radiation intensities of incident solar radiation. The results indicate that the PV-powered fans significantly outperform solar chimneys in terms of converting solar energy into the kinetic energy of air motion. Moreover, ventilation with PV-powered fans offers more flexibility in the arrangement of the ventilation system and also better control of the air flow rates in the case of battery storage.

Prospects to solar energy power generation in space. Uchu taiyo hatsuden eno tenbo

Energy Technology Data Exchange (ETDEWEB)

Kudo, I. (Electrotechnical Laboratory, Tsukuba (Japan))

1993-05-01

Solar energy power generation in space uses large arrays of solar cells developed on a geosynchronous orbit to obtain electric energy, which is transmitted to the earth using microwaves. The idea had already been advocated in 1968, which was followed a decade later by joint discussions done by NASA and DOE. The concept intended to take care of the U.S. power demand by using 60 power plant satellites, each having an output of 5 GW. This expanse of the scale, regarded reasonable even today, calls for the solar cell arrays in space spreading over an area of 10 km [times] 5 km if silicon solar cells with a conversion efficiency of 15% are used, and rectenna on the ground (a received wave converting facility) forming an ellipse of 10 km [times] 13 km (assuming a location at the north latitude of 36[degree]). Although there are a number of problems in the idea such as transportation means to lift construction materials into the space and effect of microwaves on the ionosphere and the ecosystems, the Agency of Industrial Science and Technology organized a 'committee for investigating and studying the space power generation systems' in the fiscal year 1991, and has been moving discussions forward since then. 7 refs., 5 figs.

Solar Power and Solar Fuels Synthesis Report. Technology, market and research activities 2006-2011

Energy Technology Data Exchange (ETDEWEB)

Ridell, Bengt; Nilsson, Ronny; Rehnlund, Bjoern [Grontmij, Stockholm (Sweden); Kasemo, Bengt [Chalmers Univ. of Technology, Goeteborg (Sweden)

2012-11-01

The objectives of the synthesis is to survey the situation and give an accumulated and concentrated knowledge about status, needs and opportunities for Swedish research and Swedish industry within the area of solar power and solar fuels, to be used for prioritisation of further efforts. The synthesis shall identify strengths and weaknesses in areas fundamental for development of solar power and solar fuels, focused on the development in Sweden, but in an international context. The synthesis shall also cover proposals for future Swedish research efforts and organisation of future Swedish research programs.

Thermal and optical study of parabolic trough collectors of Shiraz solar power plant

Energy Technology Data Exchange (ETDEWEB)

Mokhtari, A.; Yaghoubi, M.; Vadiee, A.; Hessami, R. [Shiraz Univ, Shiraz (Iran, Islamic Republic of); Kanan, P. [Renewable Energy Organization of Iran, Tehran (Iran, Islamic Republic of)

2007-07-01

The construction of the first 250 KW solar power plant in Shiraz, Iran was discussed. The power plant is comprised of a steam and oil cycle which includes 48 parabolic trough collectors (PTCs). Solar thermal power plants based on PTCs are currently the most successful solar technologies for electricity generation. These power plants are basically composed of a solar collector field and a power block. The solar collector field is designed to collect heat from the sun which it is continuously tracking. The reflecting surface concentrates direct solar radiation in the optical focal line of the collector where the heat collecting element (HCE) is located. The HCE absorbs the reflected energy and transmits it to the heat transfer fluid which is pumped to the conventional power block where electricity is generated. There is potential to significantly increase the performance and reduce the cost of PTC solar thermal electric technologies. However, it is necessary to characterize the optical performance and determine the optical losses of PTCs in order to improve the optical efficiency of these systems and to ensure the desired power quality. In this study, thermocouple sensors were used to record the collector oil inlet and outlet temperature along with the ambient temperature in the PTCs. In addition to measuring the wind speed, the solar beam radiation intensity was measured along with the oil's mass flow rate. All parameters were measured as a function of time. Based on these measurements, the intercept factor value and collector's incidence angle was determined and compared with other large size constructed commercial parabolic collectors. The maximum beam radiation during the experimental period was 735 2mW. The useful heat gain and the collector's instantaneous efficiency as a whole was evaluated on an hourly basis. All these parameters were strongly influenced by the incident beam radiation and found to follow each other. The optical and thermal

Geospatial Optimization of Siting Large-Scale Solar Projects

Energy Technology Data Exchange (ETDEWEB)

Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Quinby, Ted [National Renewable Energy Lab. (NREL), Golden, CO (United States); Caulfield, Emmet [Stanford Univ., CA (United States); Gerritsen, Margot [Stanford Univ., CA (United States); Diffendorfer, Jay [U.S. Geological Survey, Boulder, CO (United States); Haines, Seth [U.S. Geological Survey, Boulder, CO (United States)

2014-03-01

Recent policy and economic conditions have encouraged a renewed interest in developing large-scale solar projects in the U.S. Southwest. However, siting large-scale solar projects is complex. In addition to the quality of the solar resource, solar developers must take into consideration many environmental, social, and economic factors when evaluating a potential site. This report describes a proof-of-concept, Web-based Geographical Information Systems (GIS) tool that evaluates multiple user-defined criteria in an optimization algorithm to inform discussions and decisions regarding the locations of utility-scale solar projects. Existing siting recommendations for large-scale solar projects from governmental and non-governmental organizations are not consistent with each other, are often not transparent in methods, and do not take into consideration the differing priorities of stakeholders. The siting assistance GIS tool we have developed improves upon the existing siting guidelines by being user-driven, transparent, interactive, capable of incorporating multiple criteria, and flexible. This work provides the foundation for a dynamic siting assistance tool that can greatly facilitate siting decisions among multiple stakeholders.

Space Solar Power Program. Final report

Energy Technology Data Exchange (ETDEWEB)

Arif, Humayun; Barbosa, Hugo; Bardet, Christophe; Baroud, Michel; Behar, Alberto; Berrier, Keith; Berthe, Phillipe; Bertrand, Reinhold; Bibyk, Irene; Bisson, Joel; Bloch, Lawrence; Bobadilla, Gabriel; Bourque, Denis; Bush, Lawrence; Carandang, Romeo; Chiku, Takemi; Crosby, Norma; De Seixas, Manuel; De Vries, Joha; Doll, Susan; Dufour, Francois; Eckart, Peter; Fahey, Michael; Fenot, Frederic; Foeckersperger, Stefan; Fontaine, Jean-Emmanuel; Fowler, Robert; Frey, Harald; Fujio, Hironobu; Gasa, Jaume Munich; Gleave, Janet; Godoe, Jostein; Green, Iain; Haeberli, Roman; Hanada, Toshiya; Harris, Peter; Hucteau, Mario; Jacobs, Didier Fernand; Johnson, Richard; Kanno, Yoshitsugu; Koenig, Eva Maria; Kojima, Kazuo; Kondepudi, Phani; Kottbauer, Christian; Kulper, Doede; Kulagin, Konstantin; Kumara, Pekka; Kurz, Rainer; Laaksonen, Jyrki; Lang, Andrew Neill; Lathan, Corinna; Le Fur, Thierry; Lewis, David; Louis, Alain; Mori, Takeshi; Morlanes, Juan; Murbach, Marcus; Nagatomo, Hideo; O' brien, Ivan; Paines, Justin; Palaszewski, Bryan; Palmnaes, Ulf; Paraschivolu, Marius; Pathare, Asmin; Perov, Egor; Persson, Jan; Pessoa-Lopes, Isabel; Pinto, Michel; Porro, Irene; Reichert, Michael; Ritt-Fischer, Monika; Roberts, Margaret; Robertson II, Lawrence; Rogers, Keith; Sasaki, Tetsuo; Scire, Francesca; Shibatou, Katsuya; Shirai, Tatsuya; Shiraishi, Atsushi; Soucaille, Jean-Francois; Spivack, Nova; St. Pierre, Dany; Suleman, Afzal; Sullivan, Thomas; Theelen, Bas Johan; Thonstad, Hallvard; Tsuji, Masatoshi; Uchiumi, Masaharu; Vidqvist, Jouni; Warrell, David; Watanabe, Takafumi; Willis, Richard; Wolf, Frank; Yamakawa, Hiroshi; Zhao, Hong

1992-08-01

Information pertaining to the Space Solar Power Program is presented on energy analysis; markets; overall development plan; organizational plan; environmental and safety issues; power systems; space transportation; space manufacturing, construction, operations; design examples; and finance.

Power Management Strategy by Enhancing the Mission Profile Configuration of Solar-Powered Aircraft

Directory of Open Access Journals (Sweden)

Parvathy Rajendran

2016-01-01

Full Text Available Solar energy offers solar-powered unmanned aerial vehicle (UAV the possibility of unlimited endurance. Some researchers have developed techniques to achieve perpetual flight by maximizing the power from the sun and by flying in accordance with its azimuth angles. However, flying in a path that follows the sun consumes more energy to sustain level flight. This study optimizes the overall power ratio by adopting the mission profile configuration of optimal solar energy exploitation. Extensive simulation is conducted to optimize and restructure the mission profile phases of UAV and to determine the optimal phase definition of the start, ascent, and descent periods, thereby maximizing the energy from the sun. In addition, a vertical cylindrical flight trajectory instead of maximizing the solar inclination angle has been adopted. This approach improves the net power ratio by 30.84% compared with other techniques. As a result, the battery weight may be massively reduced by 75.23%. In conclusion, the proposed mission profile configuration with the optimal power ratio of the trajectory of the path planning effectively prolongs UAV operation.

Application of solar energy for meeting the energetic demand of large hotel objects

International Nuclear Information System (INIS)

Aycheh, B.

1993-01-01

The extensive review of renewable energy sources especially taking account the solar energy and its practical application have been described. It has been shown that the use of solar batteries for supply the large hotel objects is satisfactory only in geographic regions of very intensive isolation, e.g. in Latakia. For regions in Middle Europe, the calculations of energy needs during whole year have been shown that application of only solar energy is un-sufficient and economically unreasonable. During winter the solar installation should be supported by the sources of energy available in the region. The core full economical analysis has been done. Its results proved that e.g. for the German climate conditions the price of energy unit taken from combined solar installation is very close the price of energy obtained in conventional fossil fuel power plants. 37 refs, 48 figs, 29 tabs

Large-scale Motion of Solar Filaments

Indian Academy of Sciences (India)

tribpo

Large-scale Motion of Solar Filaments. Pavel Ambrož, Astronomical Institute of the Acad. Sci. of the Czech Republic, CZ-25165. Ondrejov, The Czech Republic. e-mail: pambroz@asu.cas.cz. Alfred Schroll, Kanzelhöehe Solar Observatory of the University of Graz, A-9521 Treffen,. Austria. e-mail: schroll@solobskh.ac.at.

Solar Energy Technician/Installer

Science.gov (United States)

Moore, Pam

2007-01-01

Solar power (also known as solar energy) is solar radiation emitted from the sun. Large panels that absorb the sun's energy as the sun beats down on them gather solar power. The energy in the rays can be used for heat (solar thermal energy) or converted to electricity (photovoltaic energy). Each solar energy project, from conception to…

Heat engine development for solar thermal power systems

Science.gov (United States)

Pham, H. Q.; Jaffe, L. D.

The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

A performance analysis of solar chimney thermal power systems

Directory of Open Access Journals (Sweden)

Al-Dabbas Awwad Mohammed

2011-01-01

Full Text Available The objective of this study was to evaluate the solar chimney performance theoretically (techno-economic. A mathematical model was developed to estimate the following parameter: Power output, Pressure drop across the turbine, the max chimney height, Airflow temperature, and the overall efficiency of solar chimney. The mathematical model was validated with experimental data from the prototype in Manzanares power. It can be concluded that the differential pressure of collector-chimney transition section in the system, is increase with the increase of solar radiation intensity. The specific system costs are between 2000 Eur/kW and 5000 Eur/kW depending on the system size, system concept and storage size. Hence, a 50 MWe solar thermal power plant will cost 100-250 Eur million. At very good sites, today’s solar thermal power plants can generate electricity in the range of 0.15 Eur/kWh, and series production could soon bring down these costs below 0.10 Eur /kWh.

Concentrating solar power: a sustainable and renewable way to get energy from solar light

International Nuclear Information System (INIS)

Montecchi, Marco

2015-01-01

Solar light irradiating the Earth is a great sustainable and renewable power source. In concentrating solar power plants, mirrors are used to redirect the solar light toward a small area where a receiver captures and converts it into thermal-energy which can be stored. ENEA has been developing the parabolic-trough Italian technology, as well as several facilities for the component characterization. The paper reports on some of those which are purely optical instruments [it

Mini Solar and Sea Current Power Generation System

Science.gov (United States)

Almenhali, Abdulrahman; Alshamsi, Hatem; Aljunaibi, Yaser; Almussabi, Dheyab; Alshehhi, Ahmed; Hilal, Hassan Bu

2017-07-01

The power demand in United Arab Emirates is increased so that there is a consistent power cut in our region. This is because of high power consumption by factories and also due to less availability of conventional energy resources. Electricity is most needed facility for the human being. All the conventional energy resources are depleting day by day. So we have to shift from conventional to non-conventional energy resources. In this the combination of two energy resources is takes place i.e. wind and solar energy. This process reviles the sustainable energy resources without damaging the nature. We can give uninterrupted power by using hybrid energy system. Basically this system involves the integration of two energy system that will give continuous power. Solar panels are used for converting solar energy and wind turbines are used for converting wind energy into electricity. This electrical power can utilize for various purpose. Generation of electricity will be takes place at affordable cost. This paper deals with the generation of electricity by using two sources combine which leads to generate electricity with affordable cost without damaging the nature balance. The purpose of this project was to design a portable and low cost power system that combines both sea current electric turbine and solar electric technologies. This system will be designed in efforts to develop a power solution for remote locations or use it as another source of green power.

Design and development of solar power-assisted manual/electric wheelchair.

Science.gov (United States)

Chien, Chi-Sheng; Huang, Tung-Yung; Liao, Tze-Yuan; Kuo, Tsung-Yuan; Lee, Tzer-Min

2014-01-01

Wheelchairs are an essential assistive device for many individuals with injury or disability. Manual wheelchairs provide a relatively low-cost solution to the mobility needs of such individuals. Furthermore, they provide an effective means of improving the user's cardiopulmonary function and upper-limb muscle strength. However, manual wheelchairs have a loss gross mechanical efficiency, and thus the risk of user fatigue and upper-limb injury is increased. Electric-powered wheelchairs reduce the risk of injury and provide a more convenient means of transportation. However, they have a large physical size and are relatively expensive. Accordingly, the present study utilizes a quality function deployment method to develop a wheelchair with a user-selectable manual/electric propulsion mode and an auxiliary solar power supply system. The auxiliary solar power supply increased the travel range of the wheelchair by approximately 26% compared with that of a wheelchair powered by battery alone. Moreover, the wheelchair has a modular design and can be disassembled and folded for ease of transportation or storage. Overall, the present results suggest that the proposed wheelchair provides an effective and convenient means of meeting the mobility needs of individuals with mobility difficulties.

A Novel Extension Decision-Making Method for Selecting Solar Power Systems

Directory of Open Access Journals (Sweden)

Meng-Hui Wang

2013-01-01

Full Text Available Due to the complex parameters of a solar power system, the designer not only must think about the load demand but also needs to consider the price, weight, and annual power generating capacity (APGC and maximum power of the solar system. It is an important task to find the optimal solar power system with many parameters. Therefore, this paper presents a novel decision-making method based on the extension theory; we call it extension decision-making method (EDMM. Using the EDMM can make it quick to select the optimal solar power system. The paper proposed this method not only to provide a useful estimated tool for the solar system engineers but also to supply the important reference with the installation of solar systems to the consumer.

Single-Phase Single-Stage Grid Tied Solar PV System with Active Power Filtering Using Power Balance Theory

Science.gov (United States)

Singh, Yashi; Hussain, Ikhlaq; Singh, Bhim; Mishra, Sukumar

2018-03-01

In this paper, power quality features such as harmonics mitigation, power factor correction with active power filtering are addressed in a single-stage, single-phase solar photovoltaic (PV) grid tied system. The Power Balance Theory (PBT) with perturb and observe based maximum power point tracking algorithm is proposed for the mitigation of power quality problems in a solar PV grid tied system. The solar PV array is interfaced to a single phase AC grid through a Voltage Source Converter (VSC), which provides active power flow from a solar PV array to the grid as well as to the load and it performs harmonics mitigation using PBT based control. The solar PV array power varies with sunlight and due to this, the solar PV grid tied VSC works only 8-10 h per day. At night, when PV power is zero, the VSC works as an active power filter for power quality improvement, and the load active power is delivered by the grid to the load connected at the point of common coupling. This increases the effective utilization of a VSC. The system is modelled and simulated using MATLAB and simulated responses of the system at nonlinear loads and varying environmental conditions are also validated experimentally on a prototype developed in the laboratory.

Solar thermal power system

Science.gov (United States)

Bennett, Charles L.

2010-06-15

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

Preliminary Feasibility Study on Application of Very Large Scale-Photovoltaic Power Generation in China

Institute of Scientific and Technical Information of China (English)

Hu Xuehao; Zhou Xiaoxin; Bai Xiaomin; Zhang Wentao

2005-01-01

Solar energy photovoltaic power generation is hopeful to be applied in a large amount and possesses a certain proportion in the structure of energy in the future. In this paper, based on the forecasting of electric load demand and energy structure of power generation in the middle of 21century, the pictures of VLS-PV power generation is composed, the operation characteristic of VLS-PV power generation and the adaptability of electric power grid for it is analyzed, the ways for transmitting large amount of PV power and the economic and technical bottlenecks for applying VLS-PV power generation are discussed. Finally, the steps and suggestions for developing VLS-PV power generation and its electric power system in China are proposed.

Solar power. [comparison of costs to wind, nuclear, coal, oil and gas

Science.gov (United States)

Walton, A. L.; Hall, Darwin C.

1990-01-01

This paper describes categories of solar technologies and identifies those that are economic. It compares the private costs of power from solar, wind, nuclear, coal, oil, and gas generators. In the southern United States, the private costs of building and generating electricity from new solar and wind power plants are less than the private cost of electricity from a new nuclear power plant. Solar power is more valuable than nuclear power since all solar power is available during peak and midpeak periods. Half of the power from nuclear generators is off-peak power and therefore is less valuable. Reliability is important in determining the value of wind and nuclear power. Damage from air pollution, when factored into the cost of power from fossil fuels, alters the cost comparison in favor of solar and wind power. Some policies are more effective at encouraging alternative energy technologies that pollute less and improve national security.

Thermal energy storage for a space solar dynamic power system

Science.gov (United States)

Faget, N. M.; Fraser, W. M., Jr.; Simon, W. E.

1985-01-01

In the past, NASA has employed solar photovoltaic devices for long-duration missions. Thus, the Skylab system has operated with a silicon photovoltaic array and a nickel-cadmium electrochemical system energy storage system. Difficulties regarding the employment of such a system for the larger power requirements of the Space Station are related to a low orbit system efficiency and the large weight of the battery. For this reason the employment of a solar dynamic power system (SDPS) has been considered. The primary components of an SDPS include a concentrating mirror, a heat receiver, a thermal energy storage (TES) system, a thermodynamic heat engine, an alternator, and a heat rejection system. The heat-engine types under consideration are a Brayton cycle engine, an organic Rankine cycle engine, and a free-piston/linear-alternator Stirling cycle engine. Attention is given to a system description, TES integration concepts, and a TES technology assessment.

Students To Race Solar-Powered Vehicles

Science.gov (United States)

4 1999 — Middle school students from across the state next week will race model solar cars designed Race Solar-Powered Vehicles For more information contact: e:mail: Public Affairs Golden, Colo., May 12 inches high. The 20-meter race is a double elimination competition with awards going to the five

Coherence-limited solar power conversion: the fundamental thermodynamic bounds and the consequences for solar rectennas

Science.gov (United States)

Mashaal, Heylal; Gordon, Jeffrey M.

2014-10-01

Solar rectifying antennas constitute a distinct solar power conversion paradigm where sunlight's spatial coherence is a basic constraining factor. In this presentation, we derive the fundamental thermodynamic limit for coherence-limited blackbody (principally solar) power conversion. Our results represent a natural extension of the eponymous Landsberg limit, originally derived for converters that are not constrained by the radiation's coherence, and are irradiated at maximum concentration (i.e., with a view factor of unity to the solar disk). We proceed by first expanding Landsberg's results to arbitrary solar view factor (i.e., arbitrary concentration and/or angular confinement), and then demonstrate how the results are modified when the converter can only process coherent radiation. The results are independent of the specific power conversion mechanism, and hence are valid for diffraction-limited as well as quantum converters (and not just classical heat engines or in the geometric optics regime). The derived upper bounds bode favorably for the potential of rectifying antennas as potentially high-efficiency solar converters.

Optimal offering strategy for a concentrating solar power plant

International Nuclear Information System (INIS)

Dominguez, R.; Baringo, L.; Conejo, A.J.

2012-01-01

Highlights: ► Concentrating solar power (CSP) plants are becoming economically viable. ► CSP production is positively correlated with the demand. ► CSP plants can be made dispatchable by using molten salt storage facilities. ► Integrating CSP plants in a market constitutes a relevant challenge. -- Abstract: This paper provides a methodology to build offering curves for a concentrating solar power plant. This methodology takes into account the uncertainty in the thermal production from the solar field and the volatility of market prices. The solar plant owner is a price-taker producer that participates in a pool-based electricity market with the aim of maximizing its expected profit. To enhance the value of the concentrating solar power plant, a molten salt heat storage is considered, which allows producing electricity during periods without availability of the solar resource. To derive offering curves, a mixed-integer linear programming model is proposed, which is robust from the point of view of the uncertainty associated with the thermal production of the solar field and stochastic from the point of view of the uncertain market prices.

Process parameter impact on properties of sputtered large-area Mo bilayers for CIGS thin film solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Badgujar, Amol C.; Dhage, Sanjay R., E-mail: dhage@arci.res.in; Joshi, Shrikant V.

2015-08-31

Copper indium gallium selenide (CIGS) has emerged as a promising candidate for thin film solar cells, with efficiencies approaching those of silicon-based solar cells. To achieve optimum performance in CIGS solar cells, uniform, conductive, stress-free, well-adherent, reflective, crystalline molybdenum (Mo) thin films with preferred orientation (110) are desirable as a back contact on large area glass substrates. The present study focuses on cylindrical rotating DC magnetron sputtered bilayer Mo thin films on 300 mm × 300 mm soda lime glass (SLG) substrates. Key sputtering variables, namely power and Ar gas flow rates, were optimized to achieve best structural, electrical and optical properties. The Mo films were comprehensively characterized and found to possess high degree of thickness uniformity over large area. Best crystallinity, reflectance and sheet resistance was obtained at high sputtering powers and low argon gas flow rates, while mechanical properties like adhesion and residual stress were found to be best at low sputtering power and high argon gas flow rate, thereby indicating a need to arrive at a suitable trade-off during processing. - Highlights: • Sputtering of bilayer molybdenum thin films on soda lime glass • Large area deposition using rotating cylindrical direct current magnetron • Trade of sputter process parameters power and pressure • High uniformity of thickness and best electrical properties obtained • Suitable mechanical and optical properties of molybdenum are achieved for CIGS application.

An analog ensemble for short-term probabilistic solar power forecast

International Nuclear Information System (INIS)

Alessandrini, S.; Delle Monache, L.; Sperati, S.; Cervone, G.

2015-01-01

Highlights: • A novel method for solar power probabilistic forecasting is proposed. • The forecast accuracy does not depend on the nominal power. • The impact of climatology on forecast accuracy is evaluated. - Abstract: The energy produced by photovoltaic farms has a variable nature depending on astronomical and meteorological factors. The former are the solar elevation and the solar azimuth, which are easily predictable without any uncertainty. The amount of liquid water met by the solar radiation within the troposphere is the main meteorological factor influencing the solar power production, as a fraction of short wave solar radiation is reflected by the water particles and cannot reach the earth surface. The total cloud cover is a meteorological variable often used to indicate the presence of liquid water in the troposphere and has a limited predictability, which is also reflected on the global horizontal irradiance and, as a consequence, on solar photovoltaic power prediction. This lack of predictability makes the solar energy integration into the grid challenging. A cost-effective utilization of solar energy over a grid strongly depends on the accuracy and reliability of the power forecasts available to the Transmission System Operators (TSOs). Furthermore, several countries have in place legislation requiring solar power producers to pay penalties proportional to the errors of day-ahead energy forecasts, which makes the accuracy of such predictions a determining factor for producers to reduce their economic losses. Probabilistic predictions can provide accurate deterministic forecasts along with a quantification of their uncertainty, as well as a reliable estimate of the probability to overcome a certain production threshold. In this paper we propose the application of an analog ensemble (AnEn) method to generate probabilistic solar power forecasts (SPF). The AnEn is based on an historical set of deterministic numerical weather prediction (NWP) model

Solar Array Power Conditioning for a Spinning Satellite

Science.gov (United States)

De Luca, Antonio; Chirulli, Giovanni

2008-09-01

The conditioning of the output power from a solar array can mainly be achieved by the adoption of DET or MPPT based architecture. There are several factors that can orientate the choice of the system designer towards one solution or the other; some of them maybe inherent to the mission derived requirements (Illumination levels, EMC cleanliness, etc.), others come directly from a careful assessment of performances and losses of both power conditioner and solar array.Definition of the criteria on which basis the final choice is justified is important as they have to guarantee a clear determination of the available versus the required power in all those mission conditions identifiable as design drivers for the overall satellite system both in terms of mass and costs.Such criteria cannot just be simple theoretical enunciations of principles; nor the meticulous definition of them on a case by case basis for different types of missions as neither option gives a guarantee of being conclusive.The aim of this paper is then to suggest assessment steps and guidelines that can be considered generically valid for any mission case, starting from the exposition of the trade off activity performed in order to choose the power conditioning solution for a spinning satellite having unregulated power bus architecture. Calculations and numerical simulations have been made in order to establish the needed solar array surface in case of adoption of a DET or MPPT solution, taking into account temperature and illumination levels on the solar cells, as well as power losses and inefficiencies from the solar generator to the main power bus, in different mission phases. Particular attention has been taken in order to correctly evaluate the thermal effects on the rest of the spacecraft as function of the adopted power system regulation.

Combined heat and power and solar energy; BHKW und solare Energie

Energy Technology Data Exchange (ETDEWEB)

Marchesi, M.; Schmidt, A.

2006-07-01

This illustrated article takes a look at a new apartment complex in Buelach, Switzerland, that meets the 'Minergie' low energy-consumption standard and also features solar-thermal heat generation. This solar installation provides heat for the provision of domestic hot water and, also, heat for the space-heating system of the building complex. The solar collectors cover an area of 153 m{sup 2}; their power is rated at 96 kW. Further elements of the building's technical services include a combined heat and power plant, a heat-pump and a gas-fired boiler. The article discusses ecological and social aspects of the design and construction of the building complex and briefly describes the installations, which also include a 'Minergie' fan-assisted balanced ventilation system.

Solar-Electrochemical Power System for a Mars Mission

Science.gov (United States)

Withrow, Colleen A.; Morales, Nelson

1994-01-01

This report documents a sizing study of a variety of solar electrochemical power systems for the intercenter NASA study known as 'Mars Exploration Reference Mission'. Power systems are characterized for a variety of rovers, habitation modules, and space transport vehicles based on requirements derived from the reference mission. The mission features a six-person crew living on Mars for 500 days. Mission power requirements range from 4 kWe to 120 kWe. Primary hydrogen and oxygen fuel cells, regenerative hydrogen and oxygen fuel cells, sodium sulfur batteries advanced photovoltaic solar arrays of gallium arsenide on germanium with tracking and nontracking mechanisms, and tent solar arrays of gallium arsenide on germanium are evaluated and compared.

Development of solar concentrators for high-power solar-pumped lasers.

Science.gov (United States)

Dinh, T H; Ohkubo, T; Yabe, T

2014-04-20

We have developed unique solar concentrators for solar-pumped solid-state lasers to improve both efficiency and laser output power. Natural sunlight is collected by a primary concentrator which is a 2  m×2  m Fresnel lens, and confined by a cone-shaped hybrid concentrator. Such solar power is coupled to a laser rod by a cylinder with coolant surrounding it that is called a liquid light-guide lens (LLGL). Performance of the cylindrical LLGL has been characterized analytically and experimentally. Since a 14 mm diameter LLGL generates efficient and uniform pumping along a Nd:YAG rod that is 6 mm in diameter and 100 mm in length, 120 W cw laser output is achieved with beam quality factor M2 of 137 and overall slope efficiency of 4.3%. The collection efficiency is 30.0  W/m2, which is 1.5 times larger than the previous record. The overall conversion efficiency is more than 3.2%, which can be comparable to a commercial lamp-pumped solid-state laser. The concept of the light-guide lens can be applied for concentrator photovoltaics or other solar energy optics.

System and method for aligning heliostats of a solar power tower

Science.gov (United States)

Convery, Mark R.

2013-01-01

Disclosed is a solar power tower heliostat alignment system and method that includes a solar power tower with a focal area, a plurality of heliostats that each reflect sunlight towards the focal area of the solar power tower, an off-focal area location substantially close to the focal area of the solar power tower, a communication link between the off-focal area location and a misaligned heliostat, and a processor that interprets the communication between the off-focal area location and the misaligned heliostat to identify the misaligned heliostat from the plurality of heliostats and that determines a correction for the identified misaligned heliostat to realign the misaligned heliostat to reflect sunlight towards the focal area of the solar power tower.

The influence of solar wind variability on magnetospheric ULF wave power

International Nuclear Information System (INIS)

Pokhotelov, D.; Rae, I.J.; Mann, I.R.

2015-01-01

Magnetospheric ultra-low frequency (ULF) oscillations in the Pc 4-5 frequency range play an important role in the dynamics of Earth's radiation belts, both by enhancing the radial diffusion through incoherent interactions and through the coherent drift-resonant interactions with trapped radiation belt electrons. The statistical distributions of magnetospheric ULF wave power are known to be strongly dependent on solar wind parameters such as solar wind speed and interplanetary magnetic field (IMF) orientation. Statistical characterisation of ULF wave power in the magnetosphere traditionally relies on average solar wind-IMF conditions over a specific time period. In this brief report, we perform an alternative characterisation of the solar wind influence on magnetospheric ULF wave activity through the characterisation of the solar wind driver by its variability using the standard deviation of solar wind parameters rather than a simple time average. We present a statistical study of nearly one solar cycle (1996-2004) of geosynchronous observations of magnetic ULF wave power and find that there is significant variation in ULF wave powers as a function of the dynamic properties of the solar wind. In particular, we find that the variability in IMF vector, rather than variabilities in other parameters (solar wind density, bulk velocity and ion temperature), plays the strongest role in controlling geosynchronous ULF power. We conclude that, although time-averaged bulk properties of the solar wind are a key factor in driving ULF powers in the magnetosphere, the solar wind variability can be an important contributor as well. This highlights the potential importance of including solar wind variability especially in studies of ULF wave dynamics in order to assess the efficiency of solar wind-magnetosphere coupling.

Retrofitting a Geothermal Plant with Solar and Storage to Increase Power Generation

Energy Technology Data Exchange (ETDEWEB)

Zhu, Guangdong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); McTigue, Joshua Dominic P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Turchi, Craig S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Castro, Jose [Coso Operating Co.; Mungas, Greg [Hyperlight Energy; Kramer, Nick [Hyperlight Energy; King, John [Hyperlight Energy

2017-10-04

Solar hybridization using concentrating solar power (CSP) can be an effective approach to augment the power generation and power cycle efficiency of a geothermal power plant with a declining resource. Thermal storage can further increase the dispatchability of a geothermal/solar hybrid system, which is particularly valued for a national grid with high renewable penetration. In this paper, a hybrid plant design with thermal storage is proposed based on the requirements of the Coso geothermal field in China Lake, California. The objective is to increase the power production by 4 MWe. In this system, a portion of the injection brine is recirculated through a heat exchanger with the solar heat transfer fluid, before being mixed with the production well brine. In the solar heating loop the brine should be heated to at least 155 degrees C to increase the net power. The solar field and storage were sized based on solar data for China Lake. Thermal storage is used to store excess power at the high-solar-irradiation hours and generate additional power during the evenings. The solar field size, the type and capacity of thermal storage and the operating temperatures are critical factors in determining the most economic hybrid system. Further investigations are required to optimize the hybrid system and evaluate its economic feasibility.

Investigation of solar photovoltaic module power output by various models

International Nuclear Information System (INIS)

Jakhrani, A.Q.; Othman, A.K.; Rigit, A.R.H.; Baini, R.

2012-01-01

This paper aims to investigate the power output of a solar photovoltaic module by various models and to formulate a suitable model for predicting the performance of solar photovoltaic modules. The model was used to correct the configurations of solar photovoltaic systems for sustainable power supply. Different types of models namely the efficiency, power, fill factor and current-voltage characteristic curve models have been reviewed. It was found that the examined models predicted a 40% yield of the rated power in cloudy weather conditions and up to 80% in clear skies. The models performed well in terms of electrical efficiency in cloudy days if the influence of low irradiance were incorporated. Both analytical and numerical methods were employed in the formulation of improved model which gave +- 2% error when compared with the rated power output of solar photovoltaic module. The proposed model is more practical in terms of number of variables used and acceptable performance in humid atmospheres. Therefore, it could be useful for the estimation of power output of the solar photovoltaic systems in Sarawak region. (author)

Lightweight Phase-Change Material For Solar Power

Science.gov (United States)

Stark, Philip

1993-01-01

Lightweight panels containing phase-change materials developed for use as heat-storage elements of compact, lightweight, advanced solar dynamic power system. During high insolation, heat stored in panels via latent heat of fusion of phase-change material; during low insolation, heat withdrawn from panels. Storage elements consist mainly of porous carbon-fiber structures imbued with germanium. Developed for use aboard space station in orbit around Earth, also adapted to lightweight, compact, portable solar-power systems for use on Earth.

Advantages of geosynchronous solar power satellites for terrestrial base-load electrical supply compared to other renewable energy sources - or why civilization needs solar power satellites

Energy Technology Data Exchange (ETDEWEB)

Strickland, J.K. Jr. [Texas Univ., Austin, TX (United States)

1998-06-01

The arguments in favour of using solar power satellites for primary base-load electrical supply are presented and compared with the advantages and drawbacks of other renewable energy sources, especially ground solar and wind systems. Popular misconceptions about energy use and the importation of space solar energy to the Earth`s surface are examined and discounted. Finally an optimal mix of space solar (focusing on geosynchronous solar power satellites), ground solar, and other energy sources is described which, it is argued, would be capable to meet future global energy demand. (UK)

Numerical simulation of the integrated solar/North Benghazi combined power plant

International Nuclear Information System (INIS)

Aldali, Y.; Morad, K.

2016-01-01

Highlights: • The thermodynamic and economic evaluation of power plant have been studied. • Saving and boosting modes are considered as the same solar field area. • Two modes of operation have been used and simulated on Libyan climate conditions. • The benefit/cost ratios are 1.74 and 1.30 for fuel saving and power boosting mode. • Fuel saving mode is more economical than power boosting mode. - Abstract: The aim of this paper is to study the thermodynamic performance of a proposed integrated solar/North Benghazi combined power plant under Libyan climatic conditions. The parabolic trough collector field with direct steam generation was considered as solar system. Two modes of operations with the same solar field area are considered: fuel saving mode in which the generated solar steam was used to preheat the combustion air in the gas turbine unit and power boosting mode in which the generated solar steam was added into the steam turbine for boosting the electrical power generated from steam turbine unit. Moreover, the economic impact of solar energy is assessed in the form of benefit/cost ratio to justify the substitution potential of such clean energy. This study shows that, for fuel saving mode: the annual saving of natural gas consumption and CO_2 emission are approximately 3001.56 and 7972.25 tons, respectively, in comparison with the conventional North Benghazi combined cycle power plant. For power boosting mode: the annual solar share of electrical energy is approximately 93.33 GW h. The economic analysis of solar supported plant has indicated that the benefit/cost ratios are 1.74 and 1.30 for fuel saving and power boosting mode, therefore, then fuel saving mode is more economical than power boosting mode for the same solar field area, moreover, it reduces the greenhouse CO_2 emission in order to avoid a collapse of the word climate.

Solar Cell and Array Technology Development for NASA Solar Electric Propulsion Missions

Science.gov (United States)

Piszczor, Michael; McNatt, Jeremiah; Mercer, Carolyn; Kerslake, Tom; Pappa, Richard

2012-01-01

NASA is currently developing advanced solar cell and solar array technologies to support future exploration activities. These advanced photovoltaic technology development efforts are needed to enable very large (multi-hundred kilowatt) power systems that must be compatible with solar electric propulsion (SEP) missions. The technology being developed must address a wide variety of requirements and cover the necessary advances in solar cell, blanket integration, and large solar array structures that are needed for this class of missions. Th is paper will summarize NASA's plans for high power SEP missions, initi al mission studies and power system requirements, plans for advanced photovoltaic technology development, and the status of specific cell and array technology development and testing that have already been conducted.

Solar Pumped High Power Solid State Laser for Space Applications

Science.gov (United States)

Fork, Richard L.; Laycock, Rustin L.; Green, Jason J. A.; Walker, Wesley W.; Cole, Spencer T.; Frederick, Kevin B.; Phillips, Dane J.

2004-01-01

Highly coherent laser light provides a nearly optimal means of transmitting power in space. The simplest most direct means of converting sunlight to coherent laser light is a solar pumped laser oscillator. A key need for broadly useful space solar power is a robust solid state laser oscillator capable of operating efficiently in near Earth space at output powers in the multi hundred kilowatt range. The principal challenges in realizing such solar pumped laser oscillators are: (1) the need to remove heat from the solid state laser material without introducing unacceptable thermal shock, thermal lensing, or thermal stress induced birefringence to a degree that improves on current removal rates by several orders of magnitude and (2) to introduce sunlight at an effective concentration (kW/sq cm of laser cross sectional area) that is several orders of magnitude higher than currently available while tolerating a pointing error of the spacecraft of several degrees. We discuss strategies for addressing these challenges. The need to remove the high densities of heat, e.g., 30 kW/cu cm, while keeping the thermal shock, thermal lensing and thermal stress induced birefringence loss sufficiently low is addressed in terms of a novel use of diamond integrated with the laser material, such as Ti:sapphire in a manner such that the waste heat is removed from the laser medium in an axial direction and in the diamond in a radial direction. We discuss means for concentrating sunlight to an effective areal density of the order of 30 kW/sq cm. The method integrates conventional imaging optics, non-imaging optics and nonlinear optics. In effect we use a method that combines some of the methods of optical pumping solid state materials and optical fiber, but also address laser media having areas sufficiently large, e.g., 1 cm diameter to handle the multi-hundred kilowatt level powers needed for space solar power.

Evaluating the potential of concentrating solar power generation in Northwestern India

International Nuclear Information System (INIS)

Purohit, Ishan; Purohit, Pallav; Shekhar, Shashaank

2013-01-01

To accelerate the decarburization in the Indian power sector, concentrating solar power (CSP) needs to play an important role. CSP technologies have found significant space in the Jawaharlal Nehru National Solar Mission (JNNSM) of the Indian government in which 20,000 MW grid connected solar power projects have been targeted by 2022 with 50% capacity for CSP. In this study a preliminary attempt has been made to assess the potential of CSP generation in the Northwestern (NW) regions of India; which seems a high potential area as it has the highest annual solar radiation in India, favorable meteorological conditions for CSP and large amount of waste land. The potential of CSP systems in NW India is estimated on the basis of a detailed solar radiation and land resource assessment. The energy yield exercise has been carried out for the representative locations using System Advisor Model for four commercially available CSP technologies namely Parabolic Trough Collector (PTC), Central receiver system (CRS), Linear Fresnel Reflector (LFR) and Parabolic Dish System (PDS). The financial viability of CSP systems at different locations in NW India is also analyzed in this study. On the basis of a detailed solar radiation and land resource assessment, the maximum theoretical potential of CSP in NW India is estimated over 2000 GW taking into accounts the viability of different CSP technologies and land suitability criteria. The technical potential is estimated over 1700 GW at an annual direct normal incidence (DNI) over 1800 kW h/m 2 and finally, the economic potential is estimated over 700 GW at an annual DNI over 2000 kW h/m 2 in NW India. It is expected that in near future locations with lower DNI values could also become financially feasible with the development of new technologies, advancement of materials, economy of scale, manufacturing capability along with the enhanced policy measures etc. With an annual DNI over 1600 kW h/m 2 it is possible to exploit over 2000 GW CSP

Cermet Coatings for Solar Stirling Space Power

Science.gov (United States)

Jaworske, Donald A.; Raack, Taylor

2004-01-01

Cermet coatings, molecular mixtures of metal and ceramic are being considered for the heat inlet surface of a solar Stirling space power converter. This paper will discuss the solar absorption characteristics of as-deposited cermet coatings as well as the solar absorption characteristics of the coatings after heating. The role of diffusion and island formation, during the deposition process and during heating will also be discussed.

Photovoltaic Test and Demonstration Project. [for solar cell power systems

Science.gov (United States)

Forestieri, A. F.; Brandhorst, H. W., Jr.; Deyo, J. N.

1976-01-01

The Photovoltaic Test and Demonstration Project was initiated by NASA in June, 1975, to develop economically feasible photovoltaic power systems suitable for a variety of terrestrial applications. Objectives include the determination of operating characteristic and lifetimes of a variety of solar cell systems and components and development of methodology and techniques for accurate measurements of solar cell and array performance and diagnostic measurements for solar power systems. Initial work will be concerned with residential applications, with testing of the first prototype system scheduled for June, 1976. An outdoor 10 kW array for testing solar power systems is under construction.

Testing, development and demonstration of large scale solar district heating systems

DEFF Research Database (Denmark)

Furbo, Simon; Fan, Jianhua; Perers, Bengt

2015-01-01

In 2013-2014 the project “Testing, development and demonstration of large scale solar district heating systems” was carried out within the Sino-Danish Renewable Energy Development Programme, the so called RED programme jointly developed by the Chinese and Danish governments. In the project Danish...... know how on solar heating plants and solar heating test technology have been transferred from Denmark to China, large solar heating systems have been promoted in China, test capabilities on solar collectors and large scale solar heating systems have been improved in China and Danish-Chinese cooperation...

The influence of solar wind variability on magnetospheric ULF wave power

Directory of Open Access Journals (Sweden)

D. Pokhotelov

2015-06-01

Full Text Available Magnetospheric ultra-low frequency (ULF oscillations in the Pc 4–5 frequency range play an important role in the dynamics of Earth's radiation belts, both by enhancing the radial diffusion through incoherent interactions and through the coherent drift-resonant interactions with trapped radiation belt electrons. The statistical distributions of magnetospheric ULF wave power are known to be strongly dependent on solar wind parameters such as solar wind speed and interplanetary magnetic field (IMF orientation. Statistical characterisation of ULF wave power in the magnetosphere traditionally relies on average solar wind–IMF conditions over a specific time period. In this brief report, we perform an alternative characterisation of the solar wind influence on magnetospheric ULF wave activity through the characterisation of the solar wind driver by its variability using the standard deviation of solar wind parameters rather than a simple time average. We present a statistical study of nearly one solar cycle (1996–2004 of geosynchronous observations of magnetic ULF wave power and find that there is significant variation in ULF wave powers as a function of the dynamic properties of the solar wind. In particular, we find that the variability in IMF vector, rather than variabilities in other parameters (solar wind density, bulk velocity and ion temperature, plays the strongest role in controlling geosynchronous ULF power. We conclude that, although time-averaged bulk properties of the solar wind are a key factor in driving ULF powers in the magnetosphere, the solar wind variability can be an important contributor as well. This highlights the potential importance of including solar wind variability especially in studies of ULF wave dynamics in order to assess the efficiency of solar wind–magnetosphere coupling.

Performance analysis of dish solar stirling power system; Stirling engine wo mochiita taiyonetsu hatsuden system no seino yosoku

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, K; Yamaguchi, I [Meiji University, Tokyo (Japan); Naito, Y; Momose, Y [Aisin Seiki Co. Ltd., Aichi (Japan)

1996-10-27

In order to estimate the performance of the dish solar Stirling power system, matching and control of each component system were studied, and the performance of the 25kWe class power system was estimated on the basis of direct solar radiation measured in Miyako island, Okinawa. Application of a Stirling engine to solar heat power generation is highly effective in spite of its small scale. The total system is composed of a converging system, heat receiver, engine/generator system and control system. As the simulation result, the generator output is nearly proportional to direct solar radiation, and the system efficiency approaches to a certain constant value with an increase in direct solar radiation. As accumulated solar radiation is large, the influence of slope error of the converging mirror is comparatively small. The optimum aperture opening ratio of the heat receiver determined on the basis of mean direct solar radiation (accumulated solar radiation/{Delta}t (simulated operation time of the system)), corresponds to the primary approximation of the opening ratio for a maximum total generated output under variable direct solar radiation. 6 refs., 6 figs., 1 tab.

Economic optimization of the energy transport component of a large distributed solar power plant

Science.gov (United States)

Turner, R. H.

1976-01-01

A solar thermal power plant with a field of collectors, each locally heating some transport fluid, requires a pipe network system for eventual delivery of energy power generation equipment. For a given collector distribution and pipe network geometry, a technique is herein developed which manipulates basic cost information and physical data in order to design an energy transport system consistent with minimized cost constrained by a calculated technical performance. For a given transport fluid and collector conditions, the method determines the network pipe diameter and pipe thickness distribution and also insulation thickness distribution associated with minimum system cost; these relative distributions are unique. Transport losses, including pump work and heat leak, are calculated operating expenses and impact the total system cost. The minimum cost system is readily selected. The technique is demonstrated on six candidate transport fluids to emphasize which parameters dominate the system cost and to provide basic decision data. Three different power plant output sizes are evaluated in each case to determine severity of diseconomy of scale.

Lunar Solar Power System Driven Human Development of the Moon and Resource-Rich Exploration of the Inner Solar System

Science.gov (United States)

Criswell, D. R.

2002-01-01

The people of Earth require, by the middle of the 21st century, a new source of commercial power that is sustainable, clean, reliable, low in cost (biosphere, and at least 4 to 5 times more abundant (> 2 kWe/person or > 20 TWe) than now (1, 2). The Lunar Solar Power (LSP) System appears to be the only reasonable option (2, 3). The Moon dependably receives 13,000 TWs of solar power. The LSP System consists of pairs of power bases located on opposite limbs of the Moon as seen from Earth. The power bases collect the solar energy and convert it to beams of microwaves. The microwaves are delivered directly to moonward-facing receivers on Earth or indirectly through relay satellites in orbit about Earth. To achieve low cost, the power bases are made primarily of local lunar materials by machines, facilities, and people deployed from Earth. Hundreds to thousands of people will be required on the Moon, in cis-lunar space, and operating tele-robotically from Earth to construct the full scale LSP System. Models indicate that power sales on Earth can easily support the required people, their regular transport between the Earth and Moon, and provide the required return on investment to develop the LSP System (4, 5). Construction of the LSP System, even at an early stage, creates fundamentally new wealth and capabilities supportive of rapid growth of human activities within the inner solar system. A factor of ten increase in global Earth-to-orbit transport will be required in the demonstration phase. Launch cost of 5,000 /kg is acceptable. Lower cost transport decreases the upfront cost of the LSP System but is not critical to the cost of energy from the mature LSP. Logistic and assembly facilities in orbit about the Earth and Moon will be required that are at least a factor of ten large than planned for the full scale International Space Station. Transport must be provided between the Earth and the Moon of hundreds, possibly thousands, of workers. Production machinery will be

Design and simulation of a geothermal–solar combined chimney power plant

International Nuclear Information System (INIS)

Cao, Fei; Li, Huashan; Ma, Qiuming; Zhao, Liang

2014-01-01

Highlights: • A geothermal–solar chimney power plant (GSCPP) is designed and analyzed. • Three different models, viz. full solar model, full geothermal model and geothermal–solar mode are compared. • Power generation under GSM is larger than the sum of FSM and FGM. • GSCPP can effectively solve the continuous operation problem of the SCPP. - Abstract: The solar chimney power plant (SCPP) is dominated by the solar radiation, and therefore its discontinuous operation is an unavoidable problem. In this paper, low temperature geothermal water is introduced into the SCPP for overcoming this problem. Based on a developed transient model, theoretical analyses are carried out to investigate the performance of the geothermal–solar chimney power plant (GSCPP) with main dimensions the same as the Manzanares prototype in Spain. Three operation models, viz. the full solar model, the full geothermal model and the geothermal–solar combined model are compared in typical summer and winter days and throughout the year. It is found that the GSCPP can attractively run in the GSM to deliver power continuously. Due to the ambient-dependant geothermal water outlet temperature, introducing the geothermal water makes greater contribution in winter days than in summer days, in the night than in the daytime. Power generation under GSM is larger than the sum of FSM and FGM. GSM is not the simple superposition of FSM and FGM, but makes better utilization of solar and geothermal energy. In addition, introducing high temperature and mass flow rate geothermal water can doubled and redoubled improve the GSCPP’s power capacity

Techno-economic evaluation of concentrating solar power generation in India

International Nuclear Information System (INIS)

Purohit, Ishan; Purohit, Pallav

2010-01-01

The Jawaharlal Nehru National Solar Mission (JNNSM) of the recently announced National Action Plan on Climate Change (NAPCC) by the Government of India aims to promote the development and use of solar energy for power generation and other uses with the ultimate objective of making solar competitive with fossil-based energy options. The plan includes specific goals to (a) create an enabling policy framework for the deployment of 20,000 MW of solar power by 2022; (b) create favourable conditions for solar manufacturing capability, particularly solar thermal for indigenous production and market leadership; (c) promote programmes for off grid applications, reaching 1000 MW by 2017 and 2000 MW by 2022, (d) achieve 15 million m 2 solar thermal collector area by 2017 and 20 million by 2022, and (e) deploy 20 million solar lighting systems for rural areas by 2022. The installed capacity of grid interactive solar power projects were 6 MW until October 2009 that is far below from their respective potential. In this study, a preliminary attempt towards the technical and economic assessment of concentrating solar power (CSP) technologies in India has been made. To analyze the techno-economic feasibility of CSP technologies in Indian conditions two projects namely PS-10 (based on power tower technology) and ANDASOL-1 (based on parabolic trough collector technology) have been taken as reference cases for this study. These two systems have been simulated at several Indian locations. The preliminary results indicate that the use of CSP technologies in India make financial sense for the north-western part of the country (particularly in Rajasthan and Gujarat states). Moreover, internalization of secondary benefits of carbon trading under clean development mechanism of the Kyoto Protocol further improves the financial feasibility of CSP systems at other locations considered in this study. It may be noted that the locations blessed with annual direct solar radiation more than 1800 k

Solar Power Ramp Events Detection Using an Optimized Swinging Door Algorithm: Preprint

Energy Technology Data Exchange (ETDEWEB)

Cui, Mingjian; Zhang, Jie; Florita, Anthony; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

2015-08-07

Solar power ramp events (SPREs) are those that significantly influence the integration of solar power on non-clear days and threaten the reliable and economic operation of power systems. Accurately extracting solar power ramps becomes more important with increasing levels of solar power penetrations in power systems. In this paper, we develop an optimized swinging door algorithm (OpSDA) to detection. First, the swinging door algorithm (SDA) is utilized to segregate measured solar power generation into consecutive segments in a piecewise linear fashion. Then we use a dynamic programming approach to combine adjacent segments into significant ramps when the decision thresholds are met. In addition, the expected SPREs occurring in clear-sky solar power conditions are removed. Measured solar power data from Tucson Electric Power is used to assess the performance of the proposed methodology. OpSDA is compared to two other ramp detection methods: the SDA and the L1-Ramp Detect with Sliding Window (L1-SW) method. The statistical results show the validity and effectiveness of the proposed method. OpSDA can significantly improve the performance of the SDA, and it can perform as well as or better than L1-SW with substantially less computation time.

Output Control Technologies for a Large-scale PV System Considering Impacts on a Power Grid

Science.gov (United States)

Kuwayama, Akira

The mega-solar demonstration project named “Verification of Grid Stabilization with Large-scale PV Power Generation systems” had been completed in March 2011 at Wakkanai, the northernmost city of Japan. The major objectives of this project were to evaluate adverse impacts of large-scale PV power generation systems connected to the power grid and develop output control technologies with integrated battery storage system. This paper describes the outline and results of this project. These results show the effectiveness of battery storage system and also proposed output control methods for a large-scale PV system to ensure stable operation of power grids. NEDO, New Energy and Industrial Technology Development Organization of Japan conducted this project and HEPCO, Hokkaido Electric Power Co., Inc managed the overall project.

Designing High Efficient Solar Powered OLED Lighting Systems

DEFF Research Database (Denmark)

Ploug, Rasmus Overgaard; Poulsen, Peter Behrensdorff; Thorsteinsson, Sune

2016-01-01

for the 10 Wp version. Furthermore, we present measurements of state-of-the-art commercial available OLED with regards to the luminous flux, luminous efficacy, luminance homogeneity, temperature dependency and IV characteristic of the OLED panels. In addition, solar powered OLED product concepts are proposed.......OLEDs used in solar powered lighting applications is a market of the future. This paper reports the development of electronic Three-Port-Converters for PV OLED product integration in the low-power area respectively for 1-10 Wp and 10-50 Wp with a peak efficiency of 97% at 1.8 W of PV power...

High performance integrated solar combined cycles with minimum modifications to the combined cycle power plant design

International Nuclear Information System (INIS)

Manente, Giovanni

2016-01-01

Highlights: • Off-design model of a 390 MW_e three pressure combined cycle developed and validated. • The off-design model is used to evaluate different hybridization schemes with solar. • Power boosting and fuel saving with different design modifications are considered. • Maximum solar share of total electricity is only 1% with the existing equipment. • The maximum incremental solar radiation-to-electrical efficiency approaches 29%. - Abstract: The integration of solar energy into natural gas combined cycles has been successfully demonstrated in several integrated solar combined cycles since the beginning of this decade in many countries. There are many motivations that drive investments on integrated solar combined cycles which are primarily the repowering of existing power plants, the compliance with more severe environmental laws on emissions and the mitigation of risks associated with large solar projects. Integrated solar combined cycles are usually developed as brownfield facilities by retrofitting existing natural gas combined cycles and keeping the existing equipment to minimize costs. In this work a detailed off-design model of a 390 MW_e three pressure level natural gas combined cycle is built to evaluate different integration schemes of solar energy which either keep the equipment of the combined cycle unchanged or include new equipment (steam turbine, heat recovery steam generator). Both power boosting and fuel saving operation strategies are analyzed in the search for the highest annual efficiency and solar share. Results show that the maximum incremental power output from solar at design solar irradiance is limited to 19 MW_e without modifications to the existing equipment. Higher values are attainable only including a larger steam turbine. High solar radiation-to-electrical efficiencies in the range 24–29% can be achieved in the integrated solar combined cycle depending on solar share and extension of tube banks in the heat recovery

Application of Power Systems Economics to Wind and Solar Power Integration

OpenAIRE

Mills, Andrew David

2015-01-01

The focus of this dissertation is the economic implications of the technical challenges of integrating variable generation, namely wind and solar, into the electric power system. The research is organized around three topics: short-term variability of wind and solar generation, changes in the economic value of wind and solar with increasing penetration, and the effectiveness of different measures at mitigating changes in economic value with increasing penetration levels. Early studies of PV g...

Phase change energy storage for solar dynamic power systems

Science.gov (United States)

Chiaramonte, F. P.; Taylor, J. D.

1992-01-01

This paper presents the results of a transient computer simulation that was developed to study phase change energy storage techniques for Space Station Freedom (SSF) solar dynamic (SD) power systems. Such SD systems may be used in future growth SSF configurations. Two solar dynamic options are considered in this paper: Brayton and Rankine. Model elements consist of a single node receiver and concentrator, and takes into account overall heat engine efficiency and power distribution characteristics. The simulation not only computes the energy stored in the receiver phase change material (PCM), but also the amount of the PCM required for various combinations of load demands and power system mission constraints. For a solar dynamic power system in low earth orbit, the amount of stored PCM energy is calculated by balancing the solar energy input and the energy consumed by the loads corrected by an overall system efficiency. The model assumes an average 75 kW SD power system load profile which is connected to user loads via dedicated power distribution channels. The model then calculates the stored energy in the receiver and subsequently estimates the quantity of PCM necessary to meet peaking and contingency requirements. The model can also be used to conduct trade studies on the performance of SD power systems using different storage materials.

Solar Power Satellites

CERN Document Server

Flournoy, Don M

2012-01-01

Communication satellites are a $144 billion industry. Is there any space-based industry that could possibly beat that market? 'Solar Power Satellites' shows why and how the space satellite industry will soon begin expanding its market from relaying signals to Earth to generating energy in space and delivering it to the ground as electricity. In all industrialized nations, energy demand is growing exponentially. In the developing world, the need for energy is as basic as food and water. The Sun's energy is available everywhere, and it is non-polluting. As business plans demonstrate its technical feasibility, commercial potential, and environmental acceptability, every country on Earth will look to space for the power it needs.

Solar-Powered Plasmon-Enhanced Heterogeneous Catalysis

Directory of Open Access Journals (Sweden)

Naldoni Alberto

2016-06-01

Full Text Available Photocatalysis uses semiconductors to convert sunlight into chemical energy. Recent reports have shown that plasmonic nanostructures can be used to extend semiconductor light absorption or to drive direct photocatalysis with visible light at their surface. In this review, we discuss the fundamental decay pathway of localized surface plasmons in the context of driving solar-powered chemical reactions. We also review different nanophotonic approaches demonstrated for increasing solar-to-hydrogen conversion in photoelectrochemical water splitting, including experimental observations of enhanced reaction selectivity for reactions occurring at the metalsemiconductor interface. The enhanced reaction selectivity is highly dependent on the morphology, electronic properties, and spatial arrangement of composite nanostructures and their elements. In addition, we report on the particular features of photocatalytic reactions evolving at plasmonic metal surfaces and discuss the possibility of manipulating the reaction selectivity through the activation of targeted molecular bonds. Finally, using solar-to-hydrogen conversion techniques as an example, we quantify the efficacy metrics achievable in plasmon-driven photoelectrochemical systems and highlight some of the new directions that could lead to the practical implementation of solar-powered plasmon-based catalytic devices.

Geothermal Risk Reduction via Geothermal/Solar Hybrid Power Plants. Final Report

Energy Technology Data Exchange (ETDEWEB)

Wendt, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mines, Greg [Idaho National Lab. (INL), Idaho Falls, ID (United States); Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhu, Guangdong [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-11-01

There are numerous technical merits associated with a renewable geothermal-solar hybrid plant concept. The performance of air-cooled binary plants is lowest when ambient temperatures are high due to the decrease in air-cooled binary plant performance that occurs when the working fluid condensing temperature, and consequently the turbine exhaust pressure, increases. Electrical power demand is generally at peak levels during periods of elevated ambient temperature and it is therefore especially important to utilities to be able to provide electrical power during these periods. The time periods in which air-cooled binary geothermal power plant performance is lowest generally correspond to periods of high solar insolation. Use of solar heat to increase air-cooled geothermal power plant performance during these periods can improve the correlation between power plant output and utility load curves. While solar energy is a renewable energy source with long term performance that can be accurately characterized, on shorter time scales of hours or days it can be highly intermittent. Concentrating solar power (CSP), aka solar-thermal, plants often incorporate thermal energy storage to ensure continued operation during cloud events or after sunset. Hybridization with a geothermal power plant can eliminate the need for thermal storage due to the constant availability of geothermal heat. In addition to the elimination of the requirement for solar thermal storage, the ability of a geothermal/solar-thermal hybrid plant to share a common power block can reduce capital costs relative to separate, stand-alone geothermal and solar-thermal power plant installations. The common occurrence of long-term geothermal resource productivity decline provides additional motivation to consider the use of hybrid power plants in geothermal power production. Geothermal resource productivity decline is a source of significant risk in geothermal power generation. Many, if not all, geothermal resources

Evaluation of the cooking power in three different solar cookers box-type

International Nuclear Information System (INIS)

Terres, H; Lizardi, A; Chávez, S; López, R; Vaca, M

2017-01-01

In the present work calculations for the cooking power in three different solar cookers are shown. The designs considered for the solar cookers are square, rectangular and octagonal. Agree to the results, a solar cooker with larger area for the solar radiation inlet has the biggest cooking power. The cooking powers obtained for the solar cookers are 4.04 W (0.49 m 2 ), 2.06 W (0.15 m 2 ) and 0.88 W (0.19 m 2 ) which correspond to square, rectangular and octagonal designs respectively. For the evaluation, the standard ASAE S580 JAN03 was considered to evaluate the cooking power in the solar cookers. Following the method established in this standard was possible to calculate the cooking power and evaluate the solar cookers at the same time. This activity except for what has been done in the standard, have not been done in other works. (paper)

Uncertainties in predicting solar panel power output

Science.gov (United States)

Anspaugh, B.

1974-01-01

The problem of calculating solar panel power output at launch and during a space mission is considered. The major sources of uncertainty and error in predicting the post launch electrical performance of the panel are considered. A general discussion of error analysis is given. Examples of uncertainty calculations are included. A general method of calculating the effect on the panel of various degrading environments is presented, with references supplied for specific methods. A technique for sizing a solar panel for a required mission power profile is developed.

Applicability of advanced automotive heat engines to solar thermal power

Science.gov (United States)

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

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

Thermodynamic evaluation of a novel solar-biomass hybrid power generation system

International Nuclear Information System (INIS)

Bai, Zhang; Liu, Qibin; Lei, Jing; Wang, Xiaohe; Sun, Jie; Jin, Hongguang

2017-01-01

Highlights: • A solar-biomass hybrid power system with zero carbon dioxide emission is proposed. • The internal mechanisms of the solar-biomass utilization are discussed. • The on-design and off-design properties of the system are numerically investigated. • The configurations of the proposed system are optimized. - Abstract: A solar-biomass hybrid power generation system, which integrates a solar thermal energy collection subsystem, a biomass steam boiler and a steam turbine power generation block, is developed for efficiently utilizing renewable energies. The solar thermal energy is concentrated by parabolic trough collectors and is used to heat the feed-water to the superheated steam of 371 °C, then the generated solar steam is further heated to a higher temperature level of 540 °C via a second-stage heating process in a biomass boiler, the system power generation capacity is about 50 MW. The hybrid process of the solar energy and biomass contributes to ameliorating the system thermodynamic performances and reducing of the exergy loss within the steam generation process. The off-design evaluation results indicate that the annual net solar-to-electric efficiency of the hybrid power system is improved to 18.13%, which is higher than that of the typical parabolic trough solar power system as 15.79%. The levelized cost of energy drops to 0.077 $/(kW h) from 0.192 $/(kW h). The annual biomass consumption rate is reduced by 22.53% in comparison with typical biomass power systems. The research findings provide a promising approach for the efficient utilization of the abundant renewable energies resources and the reduction of carbon dioxide emission.

Ultra-Portable Solar-Powered 3D Printers for Onsite Manufacturing of Medical Resources.

Science.gov (United States)

Wong, Julielynn Y

2015-09-01

The first space-based fused deposition modeling (FDM) 3D printer is powered by solar photovoltaics. This study seeks to demonstrate the feasibility of using solar energy to power a FDM 3D printer to manufacture medical resources at the Mars Desert Research Station and to design an ultra-portable solar-powered 3D printer for off-grid environments. Six solar panels in a 3×2 configuration, a voltage regulator/capacitor improvised from a power adapter, and two 12V batteries in series were connected to power a FDM 3D printer. Three designs were printed onsite and evaluated by experts post analogue mission. A solar-powered 3D printer composed of off-the-shelf components was designed to be transported in airline carry-on luggage. During the analogue mission, the solar-powered printer could only be operated for solar-powered 3D printer was designed that could print an estimated 16 dental tools or 8 mallet finger splints or 7 scalpel handles on one fully charged 12V 150Wh battery with a 110V AC converter. It is feasible to use solar energy to power a 3D printer to manufacture functional and personalized medical resources at a Mars analogue research station. Based on these findings, a solar-powered suitcase 3D printing system containing solar panels, 12V battery with charge controller and AC inverter, and back-up solar charge controller and inverter was designed for transport to and use in off-grid communities.

Dual-Axis Solar Tracking System for Maximum Power Production in ...

African Journals Online (AJOL)

Akorede

ABSTRACT: The power developed in a solar energy system depends fundamentally upon the ... for power generation. ... determined because they are functions of the solar angles that ..... able to withstand the weight and the blowing wind.

OUT Success Stories: Solar Trough Power Plants

Science.gov (United States)

Jones, J.

2000-08-01

The Solar Electric Generating System (SEGS) plants use parabolic-trough solar collectors to capture the sun's energy and convert it to heat. The SEGS plants range in capacity from 13.8 to 80 MW, and they were constructed to meet Southern California Edison Company's periods of peak power demand.

Comparing concentrating solar and nuclear power as baseload providers using the example of South Africa

International Nuclear Information System (INIS)

Pfenninger, Stefan; Keirstead, James

2015-01-01

Despite the increasing importance of variable renewable power generation, baseload, that is stable and predictable power generators, remain the backbone of many countries’ power systems. We here compare CSP (concentrating solar power) and nuclear power as baseload electricity providers for the case of South Africa, which is adding significant new generation capacity, has an abundant solar resource, but also one existing and additional planned nuclear power plants. Both of these technologies are considered baseload-capable with sufficient available fuel (sunlight or fissible material) to provide large amounts of nearly emissions-free electricity. We find that under a range of technological learning assumptions, CSP compares favorably against nuclear on costs in the period to 2030, and has lower investment and environmental risks. The results suggest that while nuclear power may be an important low-emissions power technology in regions with little sun, in the case of South Africa, CSP could be capable of providing a stable baseload supply at lower cost than nuclear power, and may have other non-cost benefits. - Highlights: • We compare nuclear and CSP (concentrating solar power) as baseload generators. • CSP could be competitive with nuclear by 2030 on providing baseload. • CSP plants producing above baseload when possible are more competitive. • On environmental and investment risks, CSP compares favorably. • Both options may have a role in different parts of the world

Solar Total Energy System, Large Scale Experiment, Shenandoah, Georgia. Final technical progress report. Volume II, Section 3. Facility concept design. [1. 72 MW thermal and 383. 6 kW electric power for 42,000 ft/sup 2/ knitwear plant

Energy Technology Data Exchange (ETDEWEB)

None,

1977-10-17

The Stearns-Roger Engineering Company conceptual design of ERDA's Large Scale Experiment No. 2 (LSE No. 2) is presented. The various LSEs are part of ERDA's Solar Total Energy Program (STES) and a separate activity of the National Solar Thermal Power Systems Program. The object of this LSE is to design, construct, test, evaluate and operate a STES for the purpose of obtaining experience with large scale hardware systems and to establish engineering capability for subsequent demonstration projects. This particular LSE is to be located at Shenandoah, Georgia, and will provide power to the Bleyle knitwear factory. The Solar Total Energy system is sized to supply 1.720 MW thermal power and 383.6 KW electrical power. The STES is sized for the extended knitwear plant of 3902 M/sup 2/ (42,000 sq-ft) which will eventually employ 300 people. The details of studies conducted for Phase II of the Solar Total Energy System (STES) for the conceptual design requirements of the facility are presented. Included in this section are the detailed descriptions and analyses of the following subtasks: facility concept design, system concept design, performance analysis, operation plan, component and subsystem development, procurement plan, cost estimating and scheduling, and technical and management plans. (WHK)

Solar radiation for sea-water desalination and electric power generation via vacuum solar collectors

International Nuclear Information System (INIS)

Mottinelli, L.; Reali, M.; El-Nashar, A.M.; Giusiano, F.; Vigotti, R.

1996-01-01

The present report concerns the energetic potential of vacuum solar which are rather versatile and efficient devices for converting solar energy into thermal energy. Two main energetic applications have been analysed: the first one for a solar sea water desalination plant which has been operated in Abu Dhabi for the past ten years, the other for a conceptual solar thermoelectric-power plant having a fair thermodynamic efficiency (15-20%). A simple technology for the manufacture of vacuum solar collectors in a standard mechanical shop is being developed in collaboration between ENEL Sp A (DSR-CRIS, Milano) and WED (Abu Dhabi). Such technology should have an important economy-saving potential per se and would also make repair and substitution operations simple enough for the actual operators of the vacuum solar collector system without any need of external assistance. The technic-operative-economical features of the Abu Dhabi solar desalination plant suggest that the use novel simplified vacuum solar collectors could have a considerable technic economical potential. The analysis of the conceptual solar thermo-electric-power plant focuses on its general layout and singles out key technological issues which ought to be addressed in an overall feasibility study. 5 figs., 3 tabs

GPP Webinar: Market Outlook and Innovations in Wind and Solar Power

Science.gov (United States)

Green Power Partnership webinar reviewing the state of the renewable energy industry as a whole, with a focus on wind and solar power and exploring recent marketplace innovations in wind and solar power and renewable energy purchases.

Space Solar Power Satellite Systems, Modern Small Satellites, and Space Rectenna

Science.gov (United States)

Bergsrud, Corey Alexis Marvin

Space solar power satellite (SSPS) systems is the concept of placing large satellite into geostationary Earth orbit (GEO) to harvest and convert massive amounts of solar energy into microwave energy, and to transmit the microwaves to a rectifying antenna (rectenna) array on Earth. The rectenna array captures and converts the microwave power into usable power that is injected into the terrestrial electric grid for use. This work approached the microwave power beam as an additional source of power (with solar) for lower orbiting satellites. Assuming the concept of retrodirectivity, a GEO-SSPS antenna array system tracks and delivers microwave power to lower orbiting satellites. The lower orbiting satellites are equipped with a stacked photovoltaic (PV)/rectenna array hybrid power generation unit (HPGU) in order to harvest solar and/or microwave energy for on-board use during orbit. The area, and mass of the PV array part of the HPGU was reduced at about 32% beginning-of-life power in order to achieve the spacecraft power requirements. The HPGU proved to offer a mass decrease in the PGU, and an increase in mission life due to longer living component life of the rectenna array. Moreover, greater mission flexibility is achieved through a track and power delivery concept. To validate the potential advantages offered by a HPGU, a mission concept was presented that utilizes modern small satellites as technology demonstrators. During launch, a smaller power receiving "daughter" satellite sits inside a larger power transmitting "mother" satellite. Once separated from the launch vehicle the daughter satellite is ejected away from the mother satellite, and each satellite deploys its respective power transmitting or power receiving hardware's for experimentation. The concept of close proximity mission operations between the satellites is considered. To validate the technology of the space rectenna array part of the HPGU, six milestones were completed in the design. The first

Evaluation end-of-life power generation of a satellite solar array

International Nuclear Information System (INIS)

Taherbaneh, Mohsen; Ghafooifard, H.; Rezaie, A.H.; Rahimi, K.

2011-01-01

Research highlights: → We present detailed design description and necessary considerations for solar panels utilized in a specific space mission. → All sources of losses and degradation of the solar panels are fully taken into account. → We introduce a comprehensive novel approach to investigate the electrical behavior of the solar panels. → We use a simple model to calculate the operating temperature range of the solar panels. → We also calculate Mission End-of-Life electrone fluence using SPENVIS. -- Abstract: Knowing the power generated by of solar arrays in a space missions shall satisfy mission requirements; prediction of the power generated by a solar array used in a space mission is very important and necessary. In this research, a detailed design description and necessary considerations for solar panels utilized in a specific space mission is presented. All sources of losses and degradation of solar panels are fully taken into account. This research emphasizes on investigation, analysis and verification of a manufactured solar assembly for a satellite before launch. Solar panels' generated power should be estimated at the end of the mission. For this purpose, radiation values and temperature operating range are specified for the mission. Panels' temperature operating rate is determined through considering a simple model and different spins for the satellite. Mission end-of-life 1 MeV equivalent dose is calculated by SPENVIS suite software. Finally, a comprehensive novel approach is introduced to investigate the electrical behavior of the solar panels. This approach can be implemented in MATLAB environment to obtain output power characteristics of the solar panels for each specific mission. The results are in full accordance with the mission requirements either in beginning-of-life or end-of-life. Therefore, the power prediction of the designed solar array for the mentioned satellite completely satisfies its mission requirements.

Effects of Power Tracking Algorithms on Lifetime of Power Electronic Devices Used in Solar Systems

Directory of Open Access Journals (Sweden)

Canras Batunlu

2016-10-01

Full Text Available In photovoltaic solar energy systems, power management algorithms (PMAs, usually called maximum power point tracking (MPPT algorithms, are widely used for extracting maximum available power at every point in time. However, tracking the maximum power has negative effects on the availability of solar energy systems. This is due, mainly, to the created disturbances and thermal stresses on the associated power electronic converters (PECs. This work investigates the effects of PMA on the lifetime consumption, thermal stresses and failures on DC-DC converters used in solar systems. Firstly theoretical analysis and modelling of photovoltaic solar systems including converter’s electro thermal characteristics were developed. Subsequently, experiments on photovoltaic solar systems were carried out using two different PMAs, namely, perturb and observe (P&O and incremental conductance (IC. Real-time data was collected, under different operating conditions, including thermal behavior using thermal imaging camera and dSPACE. Converters’ thermal cycling was found to be approximately 3 °C higher with the IC algorithm. The steady state temperature was 52.7 °C, for the IC while it was 42.6 °C for P&O. Although IC algorithm offers more accurate power management tool, it causes more severe thermal stresses which, in this study, has led to approximately 1.4 times greater life consumption compared to P&O.

Solar powered aviation beacon/landing light

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The objective of the work was to design, develop and test Solar Powered Aviation Landing Lights/Obstruction Beacons. The entire lighting units were to be stand alone devices capable of producing their own individual power supply. The whole process was to be documented to provide insight into the processes and decisions involved. (author)

A new concept of space solar power satellite

Science.gov (United States)

Li, Xun; Duan, Baoyan; Song, Liwei; Yang, Yang; Zhang, Yiqun; Wang, Dongxu

2017-07-01

Space solar power satellite (SSPS) is a tremendous energy system that collects and converts solar power to electric power in space, and then transmits the electric power to earth wirelessly. In this paper, a novel SSPS concept based on ε-near-zero (ENZ) metamaterial is proposed. A spherical condenser made of ENZ metamaterial is developed, by using the refractive property of the ENZ metamaterial sunlight can be captured and redirected to its center. To make the geometric concentration ratio of the PV array reasonable, a hemispherical one located at the center is used to collect and convert the normal-incidence sunlight to DC power, then through a phased array transmitting antenna the DC power is beamed down to the rectenna on the ground. Detailed design of the proposed concept is presented.

Dispatchable Solar Power Plant Project

Energy Technology Data Exchange (ETDEWEB)

Price, Henry [Solar Dynamics LLC, Broomfield, CO (United States)

2018-01-31

As penetration of intermittent renewable power increases, grid operators must manage greater variability in the supply and demand on the grid. One result is that utilities are planning to build many new natural gas peaking power plants that provide added flexibility needed for grid management. This report discusses the development of a dispatchable solar power (DSP) plant that can be used in place of natural gas peakers. Specifically, a new molten-salt tower (MST) plant has been developed that is designed to allow much more flexible operation than typically considered in concentrating solar power plants. As a result, this plant can provide most of the capacity and ancillary benefits of a conventional natural gas peaker plant but without the carbon emissions. The DSP system presented was designed to meet the specific needs of the Arizona Public Service (APS) utility 2017 peaking capacity request for proposals (RFP). The goal of the effort was to design a MST peaker plant that had the operational capabilities required to meet the peaking requirements of the utility and be cost competitive with the natural gas alternative. The effort also addresses many perceived barriers facing the commercial deployment of MST technology in the US today. These include MST project development issues such as permitting, avian impacts, visual impacts of tower CSP projects, project schedule, and water consumption. The DSP plant design is based on considerable analyses using sophisticated solar system design tools and in-depth preliminary engineering design. The resulting DSP plant design uses a 250 MW steam power cycle, with solar field designed to fit on a square mile plot of land that has a design point thermal rating of 400 MWt. The DSP plant has an annual capacity factor of about 16% tailored to deliver greater than 90% capacity during the critical Arizona summer afternoon peak. The table below compares the All-In energy cost and capacity payment of conventional combustion turbines

The generation of pollution-free electrical power from solar energy.

Science.gov (United States)

Cherry, W. R.

1971-01-01

Projections of the U.S. electrical power demands over the next 30 years indicate that the U.S. could be in grave danger from power shortages, undesirable effluence, and thermal pollution. An appraisal of nonconventional methods of producing electrical power is conducted, giving particular attention to the conversion of solar energy into commercial quantities of electrical power by solar cells. It is found that 1% of the land area of the 48 states could provide the total electrical power requirements of the U.S. in the year 1990. The ultimate method of generating vast quantities of electrical power would be from a series of synchronous satellites which beam microwave power back to earth to be used wherever needed. Present high manufacturing costs of solar cells could be substantially reduced by using massive automated techniques employing abundant low cost materials.

Tradeoffs and Synergies between biofuel production and large solar infrastructure in deserts.

Science.gov (United States)

Ravi, Sujith; Lobell, David B; Field, Christopher B

2014-01-01

Solar energy installations in deserts are on the rise, fueled by technological advances and policy changes. Deserts, with a combination of high solar radiation and availability of large areas unusable for crop production are ideal locations for large solar installations. However, for efficient power generation, solar infrastructures use large amounts of water for construction and operation. We investigated the water use and greenhouse gas (GHG) emissions associated with solar installations in North American deserts in comparison to agave-based biofuel production, another widely promoted potential energy source from arid systems. We determined the uncertainty in our analysis by a Monte Carlo approach that varied the most important parameters, as determined by sensitivity analysis. We considered the uncertainty in our estimates as a result of variations in the number of solar modules ha(-1), module efficiency, number of agave plants ha(-1), and overall sugar conversion efficiency for agave. Further, we considered the uncertainty in revenue and returns as a result of variations in the wholesale price of electricity and installation cost of solar photovoltaic (PV), wholesale price of agave ethanol, and cost of agave cultivation and ethanol processing. The life-cycle analyses show that energy outputs and GHG offsets from solar PV systems, mean energy output of 2405 GJ ha(-1) year(-1) (5 and 95% quantile values of 1940-2920) and mean GHG offsets of 464 Mg of CO2 equiv ha(-1) year(-1) (375-562), are much larger than agave, mean energy output from 206 (171-243) to 61 (50-71) GJ ha(-1) year(-1) and mean GHG offsets from 18 (14-22) to 4.6 (3.7-5.5) Mg of CO2 equiv ha(-1) year(-1), depending upon the yield scenario of agave. Importantly though, water inputs for cleaning solar panels and dust suppression are similar to amounts required for annual agave growth, suggesting the possibility of integrating the two systems to maximize the efficiency of land and water use to produce

Energy Non-Availability in Distribution Grids with Heavy Penetration of Solar Power: Assessment and Mitigation through Solar Smoother

Directory of Open Access Journals (Sweden)

Tathagata Sarkar

2018-03-01

Full Text Available Rapid fluctuation of solar irradiance due to cloud passage causes corresponding variations in the power output of solar PV power plants. This leads to rapid voltage instability at the point of common coupling (PCC of the connected grid which may cause temporary shutdown of the plant leading to non-availability of energy in the connected load and distribution grid. An estimate of the duration and frequency of this outage is important for solar energy generators to ensure the generation and performance of the solar power plant. A methodology using PVsyst (6.6.4, University of Geneva, Geneva, Switzerland and PSCAD (4.5, Manitoba HVDC Research Centre, Winnipeg, MB, Canada simulation has been developed to estimate the duration and frequency of power outages due to rapid fluctuation of solar irradiance throughout the year. It is shown that the outage depends not only on the solar irradiance fluctuation, but also on the grid parameters of the connected distribution grid. A practical case study has been done on a 500 kilo Watt peak (kWp solar PV power plant for validation of the proposed methodology. It is observed that the energy non-availability for this plant is about 13% per year. This can be reduced to 8% by incorporating a solar smoother. A financial analysis of this outage and its mitigation has also been carried out.

Concentrating solar power

International Nuclear Information System (INIS)

Metelli, Enzo; Vignolini, Mauro

2005-01-01

Solar energy can be used instead of fossil fuels to produce high-temperature heat for use in many industrial processes and in electricity generation. If carried out on a large scale, the replacement would make it possible to reduce harmful emissions and stabilise the global climate over the long term. ENEA has an innovative project in this sector [it

Optimization of a combined solar chimney for desalination and power generation

International Nuclear Information System (INIS)

Asayesh, Mohammad; Kasaeian, Alibakhsh; Ataei, Abtin

2017-01-01

Highlights: • One dimensional code is developed for simulation of a hybrid solar chimney. • The code is validated using experimental data of a simple solar chimney. • Partial coverage of the collector area by the desalination system is more beneficial. • The optimal configuration of the combined system is found using PSO algorithm. - Abstract: Large footprint and very low efficiency are main disadvantages of solar chimneys. To resolve this, solar desalination system has been added under the collector of a solar chimney power plant. Generally the collector ground is completely covered by the desalination pond but here it is shown that more benefit can be achieved by partial occupation of the collector area. This is performed by implementing the particle swarm optimization (PSO) algorithm in conjunction with a one dimensional simulation code. The code is first validated using data of a laboratory scale solar chimney. Then, optimization results show that for a collector diameter of 250 m and tower height of 200 m, a solar pond located between radii 85 and 125 m of the collector can maximize the outcome of the combined system. Generally, dimensions of the desalination system depend on local cost of building the system and price of electricity and fresh water produced.

Electrostatic protection of the Solar Power Satellite and rectenna

Science.gov (United States)

Freeman, J. W.; Few, A. A., Jr.; Reiff, P. H.; Cooke, D.; Bohannon, J.; Haymes, B.

1979-01-01

Several features of the interactions of the solar power satellite (SPS) with its space environment were examined theoretically. The voltages produced at various surfaces due to space plasmas and the plasma leakage currents through the kapton and sapphire solar cell blankets were calculated. At geosynchronous orbit, this parasitic power loss is only 0.7%, and is easily compensated by oversizing. At low-Earth orbit, the power loss is potentially much larger (3%), and anomalous arcing is expected for the EOTV high voltage negative surfaces. Preliminary results of a three dimensional self-consistent plasma and electric field computer program are presented, confirming the validity of the predictions made from the one dimensional models. Magnetic shielding of the satellite, to reduce the power drain and to protect the solar cells from energetic electron and plasma ion bombardment is considered. It is concluded that minor modifications can allow the SPS to operate safely and efficiently in its space environment. The SPS design employed in this study is the 1978 MSFC baseline design utilizing GaAs solar cells at CR-2 and an aluminum structure.

Feature Selection and ANN Solar Power Prediction

Directory of Open Access Journals (Sweden)

Daniel O’Leary

2017-01-01

Full Text Available A novel method of solar power forecasting for individuals and small businesses is developed in this paper based on machine learning, image processing, and acoustic classification techniques. Increases in the production of solar power at the consumer level require automated forecasting systems to minimize loss, cost, and environmental impact for homes and businesses that produce and consume power (prosumers. These new participants in the energy market, prosumers, require new artificial neural network (ANN performance tuning techniques to create accurate ANN forecasts. Input masking, an ANN tuning technique developed for acoustic signal classification and image edge detection, is applied to prosumer solar data to improve prosumer forecast accuracy over traditional macrogrid ANN performance tuning techniques. ANN inputs tailor time-of-day masking based on error clustering in the time domain. Results show an improvement in prediction to target correlation, the R2 value, lowering inaccuracy of sample predictions by 14.4%, with corresponding drops in mean average error of 5.37% and root mean squared error of 6.83%.

A 100 kW-Class Technology Demonstrator for Space Solar Power

Science.gov (United States)

Howell, J.; Carrington, C.; Day, G.

2004-12-01

A first step in the development of solar power from space is the flight demonstration of critical technologies. These fundamental technologies include efficient solar power collection and generation, power management and distribution, and thermal management. In addition, the integration and utilization of these technologies into a viable satellite bus could provide an energy-rich platform for a portfolio of payload experiments such as wireless power transmission (WPT). This paper presents the preliminary design of a concept for a 100 kW-class free-flying platform suitable for flight demonstration of Space Solar Power (SSP) technology experiments.

Solar energy powered microbial fuel cell with a reversible bioelectrode.

Science.gov (United States)

Strik, David P B T B; Hamelers, Hubertus V M; Buisman, Cees J N

2010-01-01

The solar energy powered microbial fuel cell is an emerging technology for electricity generation via electrochemically active microorganisms fueled by solar energy via in situ photosynthesized metabolites from algae, cyanobacteria, or living higher plants. A general problem with microbial fuel cells is the pH membrane gradient which reduces cell voltage and power output. This problem is caused by acid production at the anode, alkaline production at the cathode, and the nonspecific proton exchange through the membrane. Here we report a solution for a new kind of solar energy powered microbial fuel cell via development of a reversible bioelectrode responsible for both biocatalyzed anodic and cathodic electron transfer. Anodic produced protons were used for the cathodic reduction reaction which held the formation of a pH membrane gradient. The microbial fuel cell continuously generated electricity and repeatedly reversed polarity dependent on aeration or solar energy exposure. Identified organisms within biocatalyzing biofilm of the reversible bioelectrode were algae, (cyano)bacteria and protozoa. These results encourage application of solar energy powered microbial fuel cells.

A solvent- and vacuum-free route to large-area perovskite films for efficient solar modules

Science.gov (United States)

Chen, Han; Ye, Fei; Tang, Wentao; He, Jinjin; Yin, Maoshu; Wang, Yanbo; Xie, Fengxian; Bi, Enbing; Yang, Xudong; Grätzel, Michael; Han, Liyuan

2017-10-01

Recent advances in the use of organic-inorganic hybrid perovskites for optoelectronics have been rapid, with reported power conversion efficiencies of up to 22 per cent for perovskite solar cells. Improvements in stability have also enabled testing over a timescale of thousands of hours. However, large-scale deployment of such cells will also require the ability to produce large-area, uniformly high-quality perovskite films. A key challenge is to overcome the substantial reduction in power conversion efficiency when a small device is scaled up: a reduction from over 20 per cent to about 10 per cent is found when a common aperture area of about 0.1 square centimetres is increased to more than 25 square centimetres. Here we report a new deposition route for methyl ammonium lead halide perovskite films that does not rely on use of a common solvent or vacuum: rather, it relies on the rapid conversion of amine complex precursors to perovskite films, followed by a pressure application step. The deposited perovskite films were free of pin-holes and highly uniform. Importantly, the new deposition approach can be performed in air at low temperatures, facilitating fabrication of large-area perovskite devices. We reached a certified power conversion efficiency of 12.1 per cent with an aperture area of 36.1 square centimetres for a mesoporous TiO2-based perovskite solar module architecture.

Numerical evaluation of the Kalina cycle for concentrating solar power plants

DEFF Research Database (Denmark)

Modi, Anish

Concentrating solar power plants use a number of reflecting mirrors to focus and convert the incident solar energy to heat, and a power cycle to convert this heat into electricity. One of the key challenges currently faced by the solar industry is the high cost of electricity production. These co...

A Charge Controller Design For Solar Power System

OpenAIRE

Nandar Oo; Kyaw Soe Lwin; Hla Myo Tun

2015-01-01

This paper presents the solar charge controller circuit for controlling the overcharging and discharging from solar panel. This circuit regulates the charging of the battery in a solar system by monitoring battery voltage and switching the solar or other power source off when the battery reaches a preset voltage. This circuit is low voltages disconnect circuit. A charge controller circuit can increase battery life by preventing over-charging which can cause loss of electrolyte. The flow chart...

General review of solar-powered closed sorption refrigeration systems

International Nuclear Information System (INIS)

Sarbu, Ioan; Sebarchievici, Calin

2015-01-01

Highlights: • Provide review of development in solar sorption refrigeration technologies. • Theoretical basis and applications of absorption and adsorption cycles are discussed. • Thermodynamic properties of most common working pairs have been reviewed. • Development of hybrid or thermal energy storage adsorption systems was explored. • A comparison between solar-powered absorption and adsorption systems was performed. - Abstract: The negative environmental impacts of burning fossil fuels have forced the energy research community seriously to consider renewable sources, such as naturally available solar energy. Thermally powered refrigeration technologies are classified into two categories: thermo-mechanical technology and sorption technology (open systems or closed systems). This paper provides a detailed review of the solar closed sorption (absorption and adsorption) refrigeration systems, which utilise working pairs (fluids). After an introduction of the basic principles of these systems, the history of development and recent advances in solar sorption refrigeration technologies are reported. The adsorption cooling typically has a lower heat source temperature requirement than the absorption cooling. Based on the coefficient of performance (COP), the absorption systems are preferred over the adsorption systems, and the higher temperature issues can be easily handled with solar adsorption systems. The thermodynamic properties of most common working fluids, as well as the use of ternary mixtures in solar-powered absorption systems, have been reviewed in this study. The paper also refers to new approaches to increase the efficiency and sustainability of the basic adsorption cycles, such as the development of hybrid or thermal energy storage adsorption systems. This research shows that solar-powered closed sorption refrigeration technologies can be attractive alternatives not only to serve the needs for air-conditioning, refrigeration, ice making, thermal

Cost and Performance Report: Solar-Powered Remediation and pH Control

Science.gov (United States)

2017-04-01

parallel, with two batteries in each series, providing a 24 V DC power supply. A solar charge controller regulated the charging of the batteries when...ER-201033) Solar -Powered Remediation and pH Control April 2017 This document has been cleared for public release; Distribution Statement A...Technol. 32:1817-1824. CB&I Federal Services. 2017. Final Report. Solar Powered Remediation and pH Control . ESTCP Project ER-201033. April. Cheng, S

Is solar power too expensive? In the long term, no

International Nuclear Information System (INIS)

Hawkins, A. C.

2007-01-01

This short article reports on a workshop held by the International Energy Agency (IEA) in Zurich, Switzerland, which addressed the question if solar power is too expensive. The article summarises the presentations of energy and financial experts from around the world who attended the workshop. Developments in solar technology, traditional energy supply and the various applications of solar energy are discussed. Marketing aspects and price developments are examined and the risks and chances offered by the solar business are discussed. The lack of purchasing power in developing countries is also addressed.

Limits to solar power conversion efficiency with applications to quantum and thermal systems

Science.gov (United States)

Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

1983-01-01

An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

A review of large-scale solar heating systems in Europe

International Nuclear Information System (INIS)

Fisch, M.N.; Guigas, M.; Dalenback, J.O.

1998-01-01

Large-scale solar applications benefit from the effect of scale. Compared to small solar domestic hot water (DHW) systems for single-family houses, the solar heat cost can be cut at least in third. The most interesting projects for replacing fossil fuels and the reduction of CO 2 -emissions are solar systems with seasonal storage in combination with gas or biomass boilers. In the framework of the EU-APAS project Large-scale Solar Heating Systems, thirteen existing plants in six European countries have been evaluated. lie yearly solar gains of the systems are between 300 and 550 kWh per m 2 collector area. The investment cost of solar plants with short-term storage varies from 300 up to 600 ECU per m 2 . Systems with seasonal storage show investment costs twice as high. Results of studies concerning the market potential for solar heating plants, taking new collector concepts and industrial production into account, are presented. Site specific studies and predesign of large-scale solar heating plants in six European countries for housing developments show a 50% cost reduction compared to existing projects. The cost-benefit-ratio for the planned systems with long-term storage is between 0.7 and 1.5 ECU per kWh per year. (author)

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

International Nuclear Information System (INIS)

2013-05-01

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

ANALYSING SOLAR-WIND HYBRID POWER GENERATING SYSTEM

Directory of Open Access Journals (Sweden)

Mustafa ENGİN

2005-02-01

Full Text Available In this paper, a solar-wind hybrid power generating, system that will be used for security lighting was designed. Hybrid system was installed and solar cells, wind turbine, battery bank, charge regulators and inverter performance values were measured through the whole year. Using measured values of overall system efficiency, reliability, demanded energy cost per kWh were calculated, and percentage of generated energy according to resources were defined. We also include in the paper a discussion of new strategies to improve hybrid power generating system performance and demanded energy cost per kWh.

Effects of large scale integration of wind and solar energy in Japan

Science.gov (United States)

Esteban, Miguel; Zhang, Qi; Utama, Agya; Tezuka, Tetsuo; Ishihara, Keiichi

2010-05-01

results for the country as a whole are considered it is still substantial. The results are greatly dependant on the mix between the proposed renewables (solar and wind), and by comparing different distributions and mixes, the optimum composition for the target country can be established. The methodology proposed is able to obtain the optimum mix of solar and wind power for a given system, provided that adequate storage capacity exists to allow for excess capacity to be used at times of low electricity production (at the comparatively rare times when there is neither enough sun nor wind throughout the country). This highlights the challenges of large-scale integration of renewable technologies into the electricity grid, and the necessity to combine such a system with other renewables such as hydro or ocean energy to further even out the peaks and lows in the demand.

Maximizing Output Power of a Solar Panel via Combination of Sun Tracking and Maximum Power Point Tracking by Fuzzy Controllers

Directory of Open Access Journals (Sweden)

Mohsen Taherbaneh

2010-01-01

Full Text Available In applications with low-energy conversion efficiency, maximizing the output power improves the efficiency. The maximum output power of a solar panel depends on the environmental conditions and load profile. In this paper, a method based on simultaneous use of two fuzzy controllers is developed in order to maximize the generated output power of a solar panel in a photovoltaic system: fuzzy-based sun tracking and maximum power point tracking. The sun tracking is performed by changing the solar panel orientation in horizontal and vertical directions by two DC motors properly designed. A DC-DC converter is employed to track the solar panel maximum power point. In addition, the proposed system has the capability of the extraction of solar panel I-V curves. Experimental results present that the proposed fuzzy techniques result in increasing of power delivery from the solar panel, causing a reduction in size, weight, and cost of solar panels in photovoltaic systems.

Solar photovoltaic power forecasting using optimized modified extreme learning machine technique

Directory of Open Access Journals (Sweden)

Manoja Kumar Behera

2018-06-01

Full Text Available Prediction of photovoltaic power is a significant research area using different forecasting techniques mitigating the effects of the uncertainty of the photovoltaic generation. Increasingly high penetration level of photovoltaic (PV generation arises in smart grid and microgrid concept. Solar source is irregular in nature as a result PV power is intermittent and is highly dependent on irradiance, temperature level and other atmospheric parameters. Large scale photovoltaic generation and penetration to the conventional power system introduces the significant challenges to microgrid a smart grid energy management. It is very critical to do exact forecasting of solar power/irradiance in order to secure the economic operation of the microgrid and smart grid. In this paper an extreme learning machine (ELM technique is used for PV power forecasting of a real time model whose location is given in the Table 1. Here the model is associated with the incremental conductance (IC maximum power point tracking (MPPT technique that is based on proportional integral (PI controller which is simulated in MATLAB/SIMULINK software. To train single layer feed-forward network (SLFN, ELM algorithm is implemented whose weights are updated by different particle swarm optimization (PSO techniques and their performance are compared with existing models like back propagation (BP forecasting model. Keywords: PV array, Extreme learning machine, Maximum power point tracking, Particle swarm optimization, Craziness particle swarm optimization, Accelerate particle swarm optimization, Single layer feed-forward network

Space Solar Power Satellite Technology Development at the Glenn Research Center: An Overview

Science.gov (United States)

Dudenhoefer, James E.; George, Patrick J.

2000-01-01

NASA Glenn Research Center (GRC). is participating in the Space Solar Power Exploratory Research and Technology program (SERT) for the development of a solar power satellite concept. The aim of the program is to provide electrical power to Earth by converting the Sun's energy and beaming it to the surface. This paper will give an overall view of the technologies being pursued at GRC including thin film photovoltaics, solar dynamic power systems, space environmental effects, power management and distribution, and electric propulsion. The developmental path not only provides solutions to gigawatt sized space power systems for the future, but provides synergistic opportunities for contemporary space power architectures. More details of Space Solar Power can be found by reading the references sited in this paper and by connecting to the web site http://moonbase.msfc.nasa.gov/ and accessing the "Space Solar Power" section "Public Access" area.

Innovation in concentrating solar power technologies: A study drawing on patent data

OpenAIRE

Braun, Frauke G.; Hooper, Elizabeth; Wand, Robert; Zloczysti, Petra

2010-01-01

Better understanding the innovative process of renewable energy technologies is important for tackling climate change. Though concentrating solar power is receiving growing interest, innovation studies so far have explored innovative activity in solar technologies in general, ignoring the major differences between solar photovoltaic and solar thermal technologies. This study relies on patent data to examine international innovative activity in concentrating solar power technologies. Our uniqu...

The characteristic analysis of the solar energy photovoltaic power generation system

Science.gov (United States)

Liu, B.; Li, K.; Niu, D. D.; Jin, Y. A.; Liu, Y.

2017-01-01

Solar energy is an inexhaustible, clean, renewable energy source. Photovoltaic cells are a key component in solar power generation, so thorough research on output characteristics is of far-reaching importance. In this paper, an illumination model and a photovoltaic power station output power model were established, and simulation analysis was conducted using Matlab and other software. The analysis evaluated the condition of solar energy resources in the Baicheng region in the western part of Jilin province, China. The characteristic curve of the power output from a photovoltaic power station was obtained by simulation calculation. It was shown that the monthly average output power of the photovoltaic power station is affected by seasonal changes; the output power is higher in summer and autumn, and lower in spring and winter.

Progress of site survey for large solar telescopes in western China

Science.gov (United States)

Liu, Yu; Song, Tengfei; Zhang, Xuefei; Liu, Shunqing; Zhao, Mingyu; Tian, Zhanjun; Miao, Yuhu; Li, Hongbo; Huang, Jing; Su, Baoyu; Lu, Yongyin; Li, Xiaobo; Song, Qiwu

Excellent sites are necessary for developing and installing ground-based large telescopes. For very-high-resolution solar observations, it had been unclear whether there exist good candidate sites in the west areas in China, including the Tibetan Plateau and the Pamirs Plateau. The project of solar site survey for the next-generation large solar telescopes, i.e., the Chinese Giant Solar Telescope (CGST) and the large coronagraph, has been launched since 2011. Based on the close collaboration among Chinese solar society and the scientists from NSO, HAO and other institutes, we have successfully developed the standard instruments for solar site survey and applied them to more than 50 different sites distributed in Xinjiang, Tibet, Qinghai, Sichuan, Yunnan and Ningxia provinces. We have built two long-term monitoring sites in Tibet and the large Shangri-La to take systematic site data. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that a few potential sites in the large Tibetan areas should obtain the excellent astronomical conditions for our purpose to develop CGST and large coronagraph. We introduce the fresh site survey results in this report.

A Charge Controller Design For Solar Power System

Directory of Open Access Journals (Sweden)

Nandar Oo

2015-08-01

Full Text Available This paper presents the solar charge controller circuit for controlling the overcharging and discharging from solar panel. This circuit regulates the charging of the battery in a solar system by monitoring battery voltage and switching the solar or other power source off when the battery reaches a preset voltage. This circuit is low voltages disconnect circuit. A charge controller circuit can increase battery life by preventing over-charging which can cause loss of electrolyte. The flow chart is also provided.

The Solar Umbrella: A Low-cost Demonstration of Scalable Space Based Solar Power

Science.gov (United States)

Contreras, Michael T.; Trease, Brian P.; Sherwood, Brent

2013-01-01

Within the past decade, the Space Solar Power (SSP) community has seen an influx of stakeholders willing to entertain the SSP prospect of potentially boundless, base-load solar energy. Interested parties affiliated with the Department of Defense (DoD), the private sector, and various international entities have all agreed that while the benefits of SSP are tremendous and potentially profitable, the risk associated with developing an efficient end to end SSP harvesting system is still very high. In an effort to reduce the implementation risk for future SSP architectures, this study proposes a system level design that is both low-cost and seeks to demonstrate the furthest transmission of wireless power to date. The overall concept is presented and each subsystem is explained in detail with best estimates of current implementable technologies. Basic cost models were constructed based on input from JPL subject matter experts and assume that the technology demonstration would be carried out by a federally funded entity. The main thrust of the architecture is to demonstrate that a usable amount of solar power can be safely and reliably transmitted from space to the Earth's surface; however, maximum power scalability limits and their cost implications are discussed.

Solar thermal electric power generation - an attractive option for Pakistan

International Nuclear Information System (INIS)

Khan, N.A

1999-01-01

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

Solar Power Tower Design Basis Document, Revision 0

Energy Technology Data Exchange (ETDEWEB)

ZAVOICO,ALEXIS B.

2001-07-01

This report contains the design basis for a generic molten-salt solar power tower. A solar power tower uses a field of tracking mirrors (heliostats) that redirect sunlight on to a centrally located receiver mounted on top a tower, which absorbs the concentrated sunlight. Molten nitrate salt, pumped from a tank at ground level, absorbs the sunlight, heating it up to 565 C. The heated salt flows back to ground level into another tank where it is stored, then pumped through a steam generator to produce steam and make electricity. This report establishes a set of criteria upon which the next generation of solar power towers will be designed. The report contains detailed criteria for each of the major systems: Collector System, Receiver System, Thermal Storage System, Steam Generator System, Master Control System, and Electric Heat Tracing System. The Electric Power Generation System and Balance of Plant discussions are limited to interface requirements. This design basis builds on the extensive experience gained from the Solar Two project and includes potential design innovations that will improve reliability and lower technical risk. This design basis document is a living document and contains several areas that require trade-studies and design analysis to fully complete the design basis. Project- and site-specific conditions and requirements will also resolve open To Be Determined issues.

Solar PV-based rooftop power plant

International Nuclear Information System (INIS)

Ashok Kumar, B.; Kumar, Chaitanya; Patel, C.B.; Pattanaik, B.R.; Panda, P.K.; Kaul, S.K.; Mishra, H.

2017-01-01

Technical Services Division (TSD) is responsible for providing reliable power supply to various operating reactors, laboratories and facilities of BARC. The power supply to BARC is derived from TATA Power at 110 KV and 22 KV at an average HT tariff of Rs.8.49 per unit at present. Peak power demand of BARC in summer season goes up to 23 MW. TSD has implemented several energy conservation measures to reduce the energy consumption and as well taken initiatives to install solar PV based rooftop power plants to reduce the cost of energy consumption in BARC

Solar-powered hot-air system

Science.gov (United States)

1979-01-01

Solar-powered air heater supplies part or all of space heating requirements of residential or commercial buildings and is interfaced with air to water heat exchanger to heat domestic hot water. System has potential application in drying agricultural products such as cotton, lumber, corn, grains, and peanuts.

Solar Power Augmented Electrolysis Module for Energy Storage

Data.gov (United States)

National Aeronautics and Space Administration — Integrating solar photovoltaic power with regenerative fuel cell systems for energy storage can often be very complex and costly. It usually requires complex power...

Closed Cycle Engine Program Used in Solar Dynamic Power Testing Effort

Science.gov (United States)

Ensworth, Clint B., III; McKissock, David B.

1998-01-01

NASA Lewis Research Center is testing the world's first integrated solar dynamic power system in a simulated space environment. This system converts solar thermal energy into electrical energy by using a closed-cycle gas turbine and alternator. A NASA-developed analysis code called the Closed Cycle Engine Program (CCEP) has been used for both pretest predictions and post-test analysis of system performance. The solar dynamic power system has a reflective concentrator that focuses solar thermal energy into a cavity receiver. The receiver is a heat exchanger that transfers the thermal power to a working fluid, an inert gas mixture of helium and xenon. The receiver also uses a phase-change material to store the thermal energy so that the system can continue producing power when there is no solar input power, such as when an Earth-orbiting satellite is in eclipse. The system uses a recuperated closed Brayton cycle to convert thermal power to mechanical power. Heated gas from the receiver expands through a turbine that turns an alternator and a compressor. The system also includes a gas cooler and a radiator, which reject waste cycle heat, and a recuperator, a gas-to-gas heat exchanger that improves cycle efficiency by recovering thermal energy.

The Contribution of Solar Power Funding for Online Content ...

African Journals Online (AJOL)

The Contribution of Solar Power Funding for Online Content Accessibility and Sustainability of Blended Learning in Rural Africa: The Tanzania Perspective. ... Despite these appealing features, penetration of solar electricity in remote and rural areas in Tanzania is limited by high initial cost of building a stand-alone solar ...

Space-Based Solar Power System Architecture

Science.gov (United States)

2012-12-01

to this thesis, “the Boeing 702 offers a range of power up to 18 kW. Dual and triple -junction gallium arsenide solar cells enable such high power...CONCLUSIONS ........................................................................................................85 A. KEY POINTS AND...USAF. Without the proper starting point and frame of reference, this thesis would not have been possible. Thank you to everyone who had an influence on

Is Solar Power The Best Energy Option To Meet Our Future Demands

Directory of Open Access Journals (Sweden)

Samyak Shami

2015-08-01

Full Text Available Abstract Currently about 65 of global electricity generation now is fossil fuel-based spewing 13 giga tonnes of CO2 . With mass production and innovations in technology the prices of renewable energy sources have plummeted to such levels where have become a welcoming option even without the subsidies.China has installed nearly 100 gigawatts GW of wind power and plans to double it within the next five years while Britain is also in offshore wind power in a big way. However oil continues to be the most valued fuel source as almost all of it is consumed in internal combustion IC engines mostly for transport and some for captive power plants. Biofuels and hydrogen fuel cells may be used as alternatives to petrol but biofuels which include ethanol hamper the performance of a vehicle.The production cost of solar power panels has come down so much that they are competing with the coal-based power even without the subsidy. The solar powered lanterns made up of a few light-emitting diodes are bringing light and enhancing the quality of life in the worlds poorest regions which are also located in the equatorial region. The US Department of Energys target is to produce 27 of Americas electricity using solar power by 2050 up from less than 1 today. In Australia solar power panels most of them on rooftops cater to almost 10 of the demand. About 25 households of South Australia have solar power followed by Queensland 22 and Western Australia 18.Modern innovations in solar cells show enormous capabilities for them to be used extensively on windows buildings even cell phones or any device that has a clear surface. Similar strides have been made in concentrated solar power. The Solar power however has limitations too. It can not generate power during night or when sky is overcast. Excessive power generated by solar panels has led to a crisis in Germany and elsewhere to the extent that generating companies in addition to selling were also paying back the managers

False Dawn of a Solar Age: A History of Solar Heating and Power During the Energy Crisis, 1973-1986

Science.gov (United States)

Scavo, Jordan Michael

The unfolding of the energy crisis in the early 1970s brought solar to the fore as a topic for national discussion. National dialogues about solar power and national energy policy were one way that Americans interpreted their present and envisioned their nation's future. Yet, policy makers and the general public considered alternative energies, including solar, largely based on the economic conditions of their eras, considerations that, at least until the Reagan era, often transcended political ideologies and parties. Energy prices and the emerging political expediency of replacing fossil fuels were the primary drivers in shaping federal energy policies and public interest during this era. Enthusiasm for solar power often corresponded to the market price of petroleum. By the late 1970s, a lot of people believed the same. Amid growing public enthusiasm, President Carter eventually came out strongly in favor of solar energy, mounting solar panels on the White House and unveiling a plan to procure 20% of the nation's energy from the sun by the year 2000. During the 1960s and 1970s, Americans changed their energy values in response to concerns over environmentalism and the antinuclear movement. Pollution, environmental disasters, and energy crises during the 1960s and 1970s brought terms like "clean energy" and "renewable energy" into the national lexicon, and solar often served as the most prominent symbol of those ideas. At the same time, advocates presented solar as a stark contrast to nuclear: solar energy made life on earth possible; nuclear energy made it perilous. Science fiction and futurism shaped the American popular imagination through its presentation of solar technology. Each genre suffused the other and ingrained in the American national consciousness a sense of grandiose wonderment about the potential for solar energy, a potential that often did not match the contemporary applications for solar technology. The emergence of solar industries alarmed oil

Plataforma Solar de Almeria. Annual report 1997-1998. Final report; Plataforma Solar de Almeria. Haushaltsjahre 1997-1998. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-10-01

The performance and yields of thes following units and components are described: (a) Tower focus power plants and their components (TSA; RAS; Large Heliostat technology Program; Volumetric Receivers; REFOS); (b) Solar trough power stations and their components (DISS - Direct solar evaporation; ARDISS/PAREX test facility; EUROTROUGH - development of a cost-optimized European parabolic trough collector); (c) Solar chemistry (photocatalytic detoxification; solar synthesis of fine chemicals); (d) Dish/Stirling systems (HYHPIRE); (e) AP solar thermal technology transfer in the Mediterranean (THESEUS 50 MW{sub el} THErmal Solar European Power Statio at Frangokastello, Crete; SolWin; World-wide market introduction of solar thermal power stations). [German] Der bisher erzielter Erfolg und seine Auswirkungen wird fuer die folgenden Anlagen und Komponenten beschrieben. Diese sind: (a) Turmkraftwerke und deren Komponenten (TSA; RAS; Large Heliostat Technology Program; Volumetrische Receiver; REFOS), (b) Rinnenkraftwerke und deren Komponenten (DISS - Solare Direktverdampfung; ARDISS/PAREX Versuchsanlage; EUROTROUGH - Entwicklung eines kostenoptimierten europaeischen Parabolrinnenkollektors), (c) Solare Chemie (Photokatalytische Detoxifikation; Solare Synthese von Feinchemikalien), (d) Dish/Stirling Systeme (HYHPIRE), (e) AP Solarthermischer Technologietransfer im Mittelmeerraum (THESEUS - 50 MW{sub el} THErmal Solar European Power Station in Frangokastello, Kreta; SolWin; Weltweite Markteinfuehrung solarthermischer Kraftwerkstechnologie). (orig./AKF)

Thermodynamic analyses of solar thermal gasification of coal for hybrid solar-fossil power and fuel production

International Nuclear Information System (INIS)

Ng, Yi Cheng; Lipiński, Wojciech

2012-01-01

Thermodynamic analyses are performed for solar thermal steam and dry gasification of coal. The selected types of coal are anthracite, bituminous, lignite and peat. Two model conversion paths are considered for each combination of the gasifying agent and the coal type: production of the synthesis gas with its subsequent use in a combined cycle power plant to generate power, and production of the synthesis gas with its subsequent use to produce gasoline via the Fischer–Tropsch synthesis. Replacement of a coal-fired 35% efficient Rankine cycle power plant and a combustion-based integrated gasification combined cycle power plant by a solar-based integrated gasification combined cycle power plant leads to the reduction in specific carbon dioxide emissions by at least 47% and 27%, respectively. Replacement of a conventional gasoline production process via coal gasification and a subsequent Fischer–Tropsch synthesis with gasoline production via solar thermal coal gasification with a subsequent Fischer–Tropsch synthesis leads to the reduction in specific carbon dioxide emissions by at least 39%. -- Highlights: ► Thermodynamic analyses for steam and dry gasification of coal are presented. ► Hybrid solar-fossil paths to power and fuels are compared to those using only combustion. ► Hybrid power production can reduce specific CO 2 emissions by more than 27%. ► Hybrid fuel production can reduce specific CO 2 emissions by more than 39%.

Combining Energy Conversion and Storage: A Solar Powered Supercapacitor

International Nuclear Information System (INIS)

Narayanan, Remya; Kumar, P. Naresh; Deepa, Melepurath; Srivastava, Avanish Kumar

2015-01-01

Graphical abstract: - Highlights: • A plasmonic TiO_2/CdS/Au fibers photoanode is fabricated for the first time. • The efficiency of the plasmonic cell is greater by 1.35 times than the non-plasmonic one. • A solar powered supercapacitor is developed with plasmonic photoanode and multiwalled carbon nanotubes. • The solar cell current charges the supercapacitor. • A specific capacitance of 150 F g"−"1 is achieved under sunlight without any external bias. - Abstract: A solar powered supercapacitor wherein a plasmonic quantum dot solar cell (QDSC) sources the photocurrent for charging/discharging a conjoined supercapacitor based on multiwalled carbon nanotubes (MWCNTs) is demonstrated. Gold or Au fibers are integrated into a titanium dioxide/cadmium sulfide (TiO_2/CdS) electrode to yield a TiO_2/CdS/Au photoanode. The plasmonic effect of Au fibers is reflected in the higher incident photon to current conversion efficiency (IPCE = 55%) and an improved overall power conversion efficiency (3.45%) produced by the TiO_2/CdS/Au photoanode relative to the non-plasmonic TiO_2/CdS photoanode. A Janus type bi-functional electrode composed of MWCNTs on either face separated by glass is prepared and it is coupled with the TiO_2/CdS/Au electrode and another MWCNT electrode to yield the tandem solar powered supercapacitor. By channelling the photocurrent produced by the QDSC part, under 0.1 sun illumination, the capacitance of the symmetric supercapacitor, without the application of any external bias is 150 F g"−"1 which compares well with reported values of electrically powered MWCNT supercapacitors. Our innovative design for a photo-supercapacitor offers a new paradigm for combining low cost photovoltaics with energy storage to yield a technologically useful device that needs nothing else other than solar energy to run.

Duty-based control of maximum power point regulation for power converter in solar fan system with battery storage

Energy Technology Data Exchange (ETDEWEB)

Kuo, J.-L.; Hong, P.-J. [National Kaohsiung First Univ. of Science and Technology, Nantze, Kaohsiung, Taiwan (China). Dept. of Mechanical and Automation Engineering; Chao, K.-L. [National Kaohsiung Univ. of Applied Sciences, Nantze, Kaohsiung, Taiwan (China). Dept. of Electrical Engineering; Wang, T.-Y. [Chang-Gung Univ., Kwei-Shan, Tao-Yuan, Taiwan (China). Dept. of Electrical Engineering

2007-07-01

Solar energy is a popular renewable energy source for the future because it does not produce any pollution. In addition, it is unlimited and a clean source of energy. This paper discussed a photovoltaic solar fan system that could be used inside the house with the potential of cooling the indoor temperature. The solar cell module is located at the eaves of the house and could block the sunlight directly into the house, and convert solar power into electric power through the battery. The paper described software implementation and hardware circuit design in detail. The paper also illustrated a different algorithm to calculate the maximum power point regulation. The conventional algorithm calculates the solar cell module output power by multiplying the input voltage and input current for the solar cell module directly. By changing the input voltage variable into duty variable, the voltage sensor is not required under the proposed scheme. Only the duty and current variables are needed to calculate the maximum power. The microchip dsPIC microcontroller was used to implement the algorithm. Different DC link levels were verified and implemented for comparison. It was concluded that the characteristics of the solar cell module could be measured automatically, and the maximum power point could be guaranteed by the proposed algorithm. 9 refs., 6 tabs., 14 figs.

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Non-Power Purchase Agreement (PPA) Options for Financing Solar Deployment at Universities

Energy Technology Data Exchange (ETDEWEB)

2016-10-01

Financing solar using power purchase agreements (PPAs) has facilitated solar deployment of more than 100 megawatts (MW) at universities--as compared to 50 MW facilitated by financing models not using PPAs. This brochure, which overviews existing financing models and funding mechanisms available for solar procurement, focuses on non-PPA financing models. For more information on solar deployment at universities using PPAs, refer to Using Power Purchase Agreements for Solar Deployment at Universities.

Performance of double source boiler with coal-fired and solar power tower heat for supercritical power generating unit

International Nuclear Information System (INIS)

Zhang, Maolong; Du, Xiaoze; Pang, Liping; Xu, Chao; Yang, Lijun

2016-01-01

An approach of high-efficiency utilization of solar energy was proposed, by which the high concentrated heat received by the solar tower was integrated to the supercritical coal-fired boiler. Two schemes that solar energy was used to heat superheat steam or subcooled feed water were presented. The thermodynamic and heat transfer models were established. For a practical 660 MW supercritical power generating unit, the standard coal consumption of power generation could be decreased by more than 17 g/kWh by such double source boiler. The drawbacks of both schemes were found and then were amended by adding a flue gas bypass to the boiler. It also can be concluded that the maximum solar contribution of two schemes for the gross power generation are 6.11% and 4.90%, respectively. The solar power efficiency of the re-modified designs were demonstrated be superior to that of PS10. In terms of turbine efficiency, the comparisons with Solar Two plant having similar initial temperature found that the efficiency of Scheme I was 5.25% higher than that of Solar Two while the advantage of Scheme II was existing either. Additionally, in two schemes with flue bypass when the medium was extracted, the thermal efficiency of boiler could be improved as well. - Highlights: • High concentrated solar tower heat is integrated to the supercritical coal-fired boiler. • The double source boiler can use solar energy to heat superheat steam or subcooled feed water. • Power generating coal consumption can be reduced by more than 17 g/kWh by the double source boiler. • The solar contribution of double source boiler for the gross power generation can be as high as 6.11%.

Space power system utilizing Fresnel lenses for solar power and also thermal energy storage

Science.gov (United States)

Turner, R. H.

1983-01-01

A solar power plant suitable for earth orbits passing through Van Allen radiation belts is described. The solar-to-electricity conversion efficiency is estimated to be around 9 percent, and the expected power-to-weight ratio is competitive with photovoltaic arrays. The system is designed to be self-contained, to be indifferent to radiation belt exposures, store energy for periods when the orbiting system is in earth shadow (so that power generation is contant), have no moving parts and no working fluids, and be robust against micrometeorite attack. No electrical batteries are required.

Solar wind power electric plant on Vis (Croatia)

International Nuclear Information System (INIS)

1998-01-01

A project of a solar photovoltaic electric power plant presented by the Republic of Croatia at the meeting of the E.P.I.A. Mission for photovoltaic technology of the Mediterranean countries, aroused a great interest of the representatives of the invited countries. However, the interest within Croatia in the project has disappeared although E.P.I.A. offered a financing of two thirds of costs. There are attempts to construct 1800 kw wind-driven generators at the same location not taking into consideration a possibility of building a hybrid solar-wind-power electric plant. The chance that the solar part is completely of domestic origin is not accepted but the preference is given to the building of imported wind-driven generators. (orig.)

Maximum-power-point tracking control of solar heating system

KAUST Repository

Huang, Bin-Juine

2012-11-01

The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

Efficient Biomass Fuel Cell Powered by Sugar with Photo- and Thermal-Catalysis by Solar Irradiation.

Science.gov (United States)

Liu, Wei; Gong, Yutao; Wu, Weibing; Yang, Weisheng; Liu, Congmin; Deng, Yulin; Chao, Zi-Sheng

2018-06-19

The utilization of biomass sugars has received great interesting recently. Herein, we present a highly efficient hybrid solar biomass fuel cell that utilizes thermal- and photocatalysis of solar irradiation and converts biomass sugars into electricity with high power output. The fuel cell uses polyoxometalates (POMs) as photocatalyst to decompose sugars and capture their electrons. The reduced POMs have strong visible and near-infrared light adsorption, which can significantly increase the temperature of the reaction system and largely promotes the thermal oxidation of sugars by the POM. In addition, the reduced POM functions as charge carrier that can release electrons at the anode in the fuel cell to generate electricity. The electron-transfer rates from glucose to POM under thermal and light-irradiation conditions were investigated in detail. The power outputs of this solar biomass fuel cell are investigated by using different types of sugars as fuels, with the highest power density reaching 45 mW cm -2 . © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Little Eyes on Large Solar Motions

Science.gov (United States)

Kohler, Susanna

2017-10-01

Images taken during the solar eclipse in 2012. The central color composite of the eclipsed solar surface was captured by SDO, the white-light view of the solar corona around it was taken by the authors, and the background, wide-field black-and-white view is from LASCO. The white arrows mark the atypical structure. [Alzate et al. 2017]It seems like science is increasingly being done with advanced detectors on enormous ground- and space-based telescopes. One might wonder: is there anything left to learn from observations made with digital cameras mounted on 10-cm telescopes?The answer is yes plenty! Illustrating this point, a new study using such equipment recently reports on the structure and dynamics of the Suns corona during two solar eclipses.A Full View of the CoronaThe solar corona is the upper part of the Suns atmosphere, extending millions of kilometers into space. This plasma is dynamic, with changing structures that arise in response to activity on the Suns surface such as enormous ejections of energy known as coronal mass ejections (CMEs). Studying the corona is therefore important for understanding what drives its structure and how energy is released from the Sun.Though there exist a number of space-based telescopes that observe the Suns corona, they often have limited fields of view. The Solar Dynamics Observatory AIA, for instance, has spectacular resolution but only images out to 1/3 of a solar radius above the Suns limb. The space-based coronagraph LASCO C2, on the other hand, provides a broad view of the outer regions of the corona, but it only images down to 2.2 solar radii above the Suns limb. Piecing together observations from these telescopes therefore leaves a gap that prevents a full picture of the large-scale corona and how it connects to activity at the solar surface.Same as the previous figure, but for the eclipse in 2013. [Alzate et al. 2017]To provide this broad, continuous picture, a team of scientists used digital cameras mounted on 10

Performance Analysis of XCPC Powered Solar Cooling Demonstration Project

Science.gov (United States)

Widyolar, Bennett K.

A solar thermal cooling system using novel non-tracking External Compound Parabolic Concentrators (XCPC) has been built at the University of California, Merced and operated for two cooling seasons. Its performance in providing power for space cooling has been analyzed. This solar cooling system is comprised of 53.3 m2 of XCPC trough collectors which are used to power a 23 kW double effect (LiBr) absorption chiller. This is the first system that combines both XCPC and absorption chilling technologies. Performance of the system was measured in both sunny and cloudy conditions, with both clean and dirty collectors. It was found that these collectors are well suited at providing thermal power to drive absorption cooling systems and that both the coinciding of available thermal power with cooling demand and the simplicity of the XCPC collectors compared to other solar thermal collectors makes them a highly attractive candidate for cooling projects.

The economics of wind and solar variability. How the variability of wind and solar power affects their marginal value, optimal deployment, and integration costs

Energy Technology Data Exchange (ETDEWEB)

Hirth, Lion

2014-11-14

Variable renewable energy sources (VRE) for electricity generation, such as wind and solar power, are subject to inherent output fluctuations. This variability has significant impacts on power system and electricity markets if VRE are deployed at large scale. While on global average, wind and solar power currently supply only a minor share of electricity, they are expected to play a much larger role in the future - such that variability will become a major issue (which it already is in some regions). This thesis contributes to the literature that assesses these impacts the ''system and market integration'' literature. This thesis aims at answering the question: What is the impact of wind and solar power variability on the economics of these technologies? It will be laid out that the impact can be expressed in (at least) three ways: as reduction of value, as increase of cost, or as decrease of optimal deployment. Translating between these perspectives is not trivial, as evidenced by the confusion around the concept of ''integration costs''. Hence, more specifically: How does variability impact the marginal economic value of these power sources, their optimal deployment, and their integration costs? This is the question that this thesis addresses. This study comprises six papers, of which two develop a valuation framework that accounts for the specific characteristics of the good electricity, and the specific properties of wind and solar power versus ''dispatchable'' power plants. Three articles then assess quantitative questions and estimate marginal value, optimal deployment, and integration costs. These estimates stem from a newly developed numerical power market model, EMMA, market data, and quantitative literature reviews. The final paper addresses market design. In short, the principal findings of this thesis are as follows. Electricity is a peculiar economic good, being at the same time perfectly

The economics of wind and solar variability. How the variability of wind and solar power affects their marginal value, optimal deployment, and integration costs

International Nuclear Information System (INIS)

Hirth, Lion

2014-01-01

Variable renewable energy sources (VRE) for electricity generation, such as wind and solar power, are subject to inherent output fluctuations. This variability has significant impacts on power system and electricity markets if VRE are deployed at large scale. While on global average, wind and solar power currently supply only a minor share of electricity, they are expected to play a much larger role in the future - such that variability will become a major issue (which it already is in some regions). This thesis contributes to the literature that assesses these impacts the ''system and market integration'' literature. This thesis aims at answering the question: What is the impact of wind and solar power variability on the economics of these technologies? It will be laid out that the impact can be expressed in (at least) three ways: as reduction of value, as increase of cost, or as decrease of optimal deployment. Translating between these perspectives is not trivial, as evidenced by the confusion around the concept of ''integration costs''. Hence, more specifically: How does variability impact the marginal economic value of these power sources, their optimal deployment, and their integration costs? This is the question that this thesis addresses. This study comprises six papers, of which two develop a valuation framework that accounts for the specific characteristics of the good electricity, and the specific properties of wind and solar power versus ''dispatchable'' power plants. Three articles then assess quantitative questions and estimate marginal value, optimal deployment, and integration costs. These estimates stem from a newly developed numerical power market model, EMMA, market data, and quantitative literature reviews. The final paper addresses market design. In short, the principal findings of this thesis are as follows. Electricity is a peculiar economic good, being at the same time perfectly

Vestas Power Plant Solutions Integrating Wind, Solar PV and Energy Storage

DEFF Research Database (Denmark)

Petersen, Lennart; Hesselbæk, Bo; Martinez, Antonio

2018-01-01

This paper addresses a value proposition and feasible system topologies for hybrid power plant solutions integrating wind, solar PV and energy storage and moreover provides insights into Vestas hybrid power plant projects. Seen from the perspective of a wind power plant developer, these hybrid...... solutions provide a number of benefits that could potentially reduce the Levelized Cost of Energy and enable entrance to new markets for wind power and facilitate the transition to a more sustainable energy mix. First, various system topologies are described in order to distinguish the generic concepts...... for the electrical infrastructure of hybrid power plants. Subsequently, the benefits of combining wind and solar PV power as well as the advantages of combining variable renewable energy sources with energy storage are elaborated. Finally, the world’s first utility-scale hybrid power plant combining wind, solar PV...

The research and development of the automatic solar power tracker

OpenAIRE

Li Yan Ping; Yuan Zhong Ying

2016-01-01

The article describes a kind of automatic tracker using solar power. It depends on two important parts which are servo system and adjusting mechanism system to keep the tracker operating normally. The article focuses on describing the characteristics and functions of two systems and the operating details of the automatic solar power tracker.

Solar thermal energy conversion to electrical power

International Nuclear Information System (INIS)

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

2014-01-01

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

Choice of antenna geometry for microwave power transmission from solar power satellites

Science.gov (United States)

Potter, Seth D.

1992-01-01

A comparison is made between square and circular transmitting antennas for solar power satellite microwave power transmission. It is seen that the exclusion zone around the rectenna needed to protect populations from microwaves is smaller for a circular antenna operating at 2.45 GHz than it is for a square antenna at that frequency. If the frequency is increased, the exclusion zone size remains the same for a square antenna, but becomes even smaller for a circular antenna. Peak beam intensity is the same for both antennas if the frequency and antenna area are equal. The circular antenna puts a somewhat greater amount of power in the main lobe and somewhat less in the side lobes. Since rain attenuation and atmospheric heating remain problems above 10 GHz, it is recommended that future solar power satellite work concentrate on circular transmitting antennas at frequencies of roughly 10 GHz.

Solar power plant performance evaluation: simulation and experimental validation

Science.gov (United States)

Natsheh, E. M.; Albarbar, A.

2012-05-01

In this work the performance of solar power plant is evaluated based on a developed model comprise photovoltaic array, battery storage, controller and converters. The model is implemented using MATLAB/SIMULINK software package. Perturb and observe (P&O) algorithm is used for maximizing the generated power based on maximum power point tracker (MPPT) implementation. The outcome of the developed model are validated and supported by a case study carried out using operational 28.8kW grid-connected solar power plant located in central Manchester. Measurements were taken over 21 month's period; using hourly average irradiance and cell temperature. It was found that system degradation could be clearly monitored by determining the residual (the difference) between the output power predicted by the model and the actual measured power parameters. It was found that the residual exceeded the healthy threshold, 1.7kW, due to heavy snow in Manchester last winter. More important, the developed performance evaluation technique could be adopted to detect any other reasons that may degrade the performance of the P V panels such as shading and dirt. Repeatability and reliability of the developed system performance were validated during this period. Good agreement was achieved between the theoretical simulation and the real time measurement taken the online grid connected solar power plant.

Design of DSP-based high-power digital solar array simulator

Science.gov (United States)

Zhang, Yang; Liu, Zhilong; Tong, Weichao; Feng, Jian; Ji, Yibo

2013-12-01

To satisfy rigid performance specifications, a feedback control was presented for zoom optical lens plants. With the increasing of global energy consumption, research of the photovoltaic(PV) systems get more and more attention. Research of the digital high-power solar array simulator provides technical support for high-power grid-connected PV systems research.This paper introduces a design scheme of the high-power digital solar array simulator based on TMS320F28335. A DC-DC full-bridge topology was used in the system's main circuit. The switching frequency of IGBT is 25kHz.Maximum output voltage is 900V. Maximum output current is 20A. Simulator can be pre-stored solar panel IV curves.The curve is composed of 128 discrete points .When the system was running, the main circuit voltage and current values was feedback to the DSP by the voltage and current sensors in real-time. Through incremental PI,DSP control the simulator in the closed-loop control system. Experimental data show that Simulator output voltage and current follow a preset solar panels IV curve. In connection with the formation of high-power inverter, the system becomes gridconnected PV system. The inverter can find the simulator's maximum power point and the output power can be stabilized at the maximum power point (MPP).

TIME DISTRIBUTIONS OF LARGE AND SMALL SUNSPOT GROUPS OVER FOUR SOLAR CYCLES

International Nuclear Information System (INIS)

Kilcik, A.; Yurchyshyn, V. B.; Abramenko, V.; Goode, P. R.; Cao, W.; Ozguc, A.; Rozelot, J. P.

2011-01-01

Here we analyze solar activity by focusing on time variations of the number of sunspot groups (SGs) as a function of their modified Zurich class. We analyzed data for solar cycles 20-23 by using Rome (cycles 20 and 21) and Learmonth Solar Observatory (cycles 22 and 23) SG numbers. All SGs recorded during these time intervals were separated into two groups. The first group includes small SGs (A, B, C, H, and J classes by Zurich classification), and the second group consists of large SGs (D, E, F, and G classes). We then calculated small and large SG numbers from their daily mean numbers as observed on the solar disk during a given month. We report that the time variations of small and large SG numbers are asymmetric except for solar cycle 22. In general, large SG numbers appear to reach their maximum in the middle of the solar cycle (phases 0.45-0.5), while the international sunspot numbers and the small SG numbers generally peak much earlier (solar cycle phases 0.29-0.35). Moreover, the 10.7 cm solar radio flux, the facular area, and the maximum coronal mass ejection speed show better agreement with the large SG numbers than they do with the small SG numbers. Our results suggest that the large SG numbers are more likely to shed light on solar activity and its geophysical implications. Our findings may also influence our understanding of long-term variations of the total solar irradiance, which is thought to be an important factor in the Sun-Earth climate relationship.

Thermo-economic analysis of Shiraz solar thermal power plant

Energy Technology Data Exchange (ETDEWEB)

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

2007-07-01

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

The COronal Solar Magnetism Observatory (COSMO) Large Aperture Coronagraph

Science.gov (United States)

Tomczyk, Steve; Gallagher, Dennis; Wu, Zhen; Zhang, Haiying; Nelson, Pete; Burkepile, Joan; Kolinksi, Don; Sutherland, Lee

2013-04-01

The COSMO is a facility dedicated to observing coronal and chromospheric magnetic fields. It will be located on a mountaintop in the Hawaiian Islands and will replace the current Mauna Loa Solar Observatory (MLSO). COSMO will provide unique observations of the global coronal magnetic fields and its environment to enhance the value of data collected by other observatories on the ground (e.g. SOLIS, BBO NST, Gregor, ATST, EST, Chinese Giant Solar Telescope, NLST, FASR) and in space (e.g. SDO, Hinode, SOHO, GOES, STEREO, Solar-C, Solar Probe+, Solar Orbiter). COSMO will employ a fleet of instruments to cover many aspects of measuring magnetic fields in the solar atmosphere. The dynamics and energy flow in the corona are dominated by magnetic fields. To understand the formation of CMEs, their relation to other forms of solar activity, and their progression out into the solar wind requires measurements of coronal magnetic fields. The large aperture coronagraph, the Chromospheric and Prominence Magnetometer and the K-Coronagraph form the COSMO instrument suite to measure magnetic fields and the polarization brightness of the low corona used to infer electron density. The large aperture coronagraph will employ a 1.5 meter fuse silica singlet lens, birefringent filters, and a spectropolarimeter to cover fields of view of up to 1 degree. It will observe the corona over a wide range of emission lines from 530.3 nm through 1083.0 nm allowing for magnetic field measurements over a wide range of coronal temperatures (e.g. FeXIV at 530.3 nm, Fe X at 637.4 nm, Fe XIII at 1074.7 and 1079.8 nm. These lines are faint and require the very large aperture. NCAR and NSF have provided funding to bring the large aperture coronagraph to a preliminary design review state by the end of 2013. As with all data from Mauna Loa, the data products from COSMO will be available to the community via the Mauna Loa website: http://mlso.hao.ucar.edu

Control of Solar Power Plants Connected Grid with Simple Calculation Method on Residential Homes

Science.gov (United States)

Kananda, Kiki; Nazir, Refdinal

2017-12-01

One of the most compatible renewable energy in all regions to apply is solar energy. Solar power plants can be built connected to existing or stand-alone power grids. In assisting the residential electricity in which there is a power grid, then a small scale solar energy power plants is very appropriate. However, the general constraint of solar energy power plants is still low in terms of efficiency. Therefore, this study will explain how to control the power of solar power plants more optimally, which is expected to reactive power to zero to raise efficiency. This is a continuation of previous research using Newton Rapshon control method. In this study we introduce a simple method by using ordinary mathematical calculations of solar-related equations. In this model, 10 PV modules type of ND T060M1 with a 60 Wp capacity are used. The calculations performed using MATLAB Simulink provide excellent value. For PCC voltage values obtained a stable quantity of approximately 220 V. At a maximum irradiation condition of 1000 W / m2, the reactive power value of Q solar generating system maximum 20.48 Var and maximum active power of 417.5 W. In the condition of lower irradiation, value of reactive power Q almost close to zero 0.77Var. This simple mathematical method can provide excellent quality control power values.