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Parabolic Trough Solar Power for Competitive U.S. Markets

Description: 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.
Date: November 1, 1998
Creator: Price, Henry W.
Partner: UNT Libraries Government Documents Department

Solar-Electric Dish Stirling System Development

Description: Electrical power generated with the heat from the sun, called solar thermal power, is produced with three types of concentrating solar systems - trough or line-focus systems; power towers in which a centrally-located thermal receiver is illuminated with a large field of sun-tracking heliostats; and dish/engine systems. A special case of the third type of system, a dish/Stirling system, is the subject of this paper. A dish/Stirling system comprises a parabolic dish concentrator, a thermal receiver, and a Stirling engine/generator located at the focus of the dish. Several different dish/Stirling systems have been built and operated during the past 15 years. One system claims the world record for net conversion of solar energy to electric power of 29.4%; and two different company`s systems have accumulated thousands of hours of on-sun operation. Due to de-regulation and intense competition in global energy markets as well as the immaturity of the technology, dish/Stirling systems have not yet found their way into the marketplace. This situation is changing as solar technologies become more mature and manufacturers identify high-value niche markets for their products. In this paper, I review the history of dish/Stirling system development with an emphasis on technical and other issues that directly impact the Stirling engine. I also try to provide some insight to the opportunities and barriers confronting the application of dish/Stirling in power generation markets.
Date: December 31, 1997
Creator: Mancini, T.R.
Partner: UNT Libraries Government Documents Department

Solar thermal electricity in 1998: An IEA/SolarPACES summary of status and future prospects

Description: Research and development activities sponsored by countries within the International Energy Agency`s solar thermal working group. SolarPACES, have helped reduce the cost of solar thermal systems to one-fifth that of the early pilot plants. Continued technological improvements are currently being proven in next-generation demonstration plants. These advances, along with cost reductions made possible by scale-up to larger production and construction of a succession of power plants, have made solar thermal systems the lowest-cost solar energy in the world and promise cost-competitiveness with fossil-fuel plants in the future. Solar thermal technologies are appropriate for a wide range of applications, including dispatchable central-station power plants where they can meet peak-load to near-base-load needs of a utility, and distributed, modular power plants for both remote and grid-connected applications. In this paper, the authors present the collective position of the SolarPACES community on solar electricity-generating technology. They discuss the current status of the technology and likely near-term improvements; the needs of target markets; and important technical and financial issues that must be resolved for success in near-term global markets.
Date: July 1, 1998
Creator: Tyner, C.E.; Kolb, G.J.; Meinecke, W. & Trieb, F.
Partner: UNT Libraries Government Documents Department

Initial appraisal of solar thermal electric energy in Tibet and Xinjiang Provinces, People`s Republic of China

Description: At the request of US sponsors Spencer Management Associates (SMA) and Sun{diamond}Lab, China`s Center for Renewable Energy Development and former Ministry of Electric Power conducted an initial appraisal of the issues involved with developing China`s first solar thermal electric power plant in the sunbelt regions of Tibet or Xinjiang provinces. The appraisal concerns development of a large-scale, grid-connected solar trough or tower project capable of producing 30 or more megawatts of electricity. Several of the findings suggest that Tibet could be a niche market for solar thermal power because a solar plant may be the low-cost option relative to other methods of generating electricity. China has studied the concept of a solar thermal power plant for quite some time. In 1992, it completed a pre-feasibility study for a SEGS-type parabolic trough plant with the aid of Israel`s United Development Limited. Because the findings were positive, both parties agreed to conduct a full-scale feasibility study. However, due to funding constraints, the study was postponed. Most recently, Sun{diamond}Lab and SMA asked China to broaden the analysis to include tower as well as trough concepts. The findings of this most recent investigation completed i November of 1997, are the subject of this paper. The main conclusions of all studies conducted to date suggest that a region in the proximity of Lhasa, Tibet, offers the best near-term opportunity within China. The opportunities for solar thermal power plants in other regions of China were also investigated.
Date: July 1, 1998
Creator: Junfeng, Li; Li, Zhu; Zhan, Liu; Yuan, Zhang; Washom, Byron & Kolb, Gregory
Partner: UNT Libraries Government Documents Department

Final Report on the Operation and Maintenance Improvement Program for Concentrating Solar Power Plants

Description: This report describes the results of a six-year, $6.3 million project to reduce operation and maintenance (O&M) costs at power plants employing concentrating solar power (CSP) technology. Sandia National Laboratories teamed with KJC Operating Company to implement the O&M Improvement Program. O&M technologies developed during the course of the program were demonstrated at the 150-MW Kramer Junction solar power park located in Boron, California. Improvements were made in the following areas: (a) efficiency of solar energy collection, (b) O&M information management, (c) reliability of solar field flow loop hardware, (d) plant operating strategy, and (e) cost reduction associated with environmental issues. A 37% reduction in annual O&M costs was achieved. Based on the lessons learned, an optimum solar- field O&M plan for future CSP plants is presented. Parabolic trough solar technology is employed at Kramer Junction. However, many of the O&M improvements described in the report are also applicable to CSP plants based on solar power tower or dish/engine concepts.
Date: June 1, 1999
Creator: E., Cohen Gilbert; Kearney, David W. & Kolb, Gregory J.
Partner: UNT Libraries Government Documents Department

Financing Solar Thermal Power Plants

Description: 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 i n 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.
Date: November 1, 1999
Creator: Price, H. W. & Kistner, R.
Partner: UNT Libraries Government Documents Department

Performance test plan for a space station toluene heater tube

Description: Sundstrand Energy Systems was awarded a contract to investigate the performance capabilities of a toluene heater tube integral to a heat pipe as applied to the Organic Rankine Cycle (ORC) solar dynamic power system for the Space Station. This heat pipe is a subassembly of the heat receiver. The heat receiver, the heat absorption component of the ORC solar dynamic power system, consists of forty liquid metal heat pipes located circumferentially around the heat receiver`s outside diameter. Each heat pipe contains a toluene heater, two thermal energy storage (TES) canisters and potassium. The function of the heater tube is to heat the supercritical toluene to the required turbine inlet temperature. During the orbit of the space station, the heat receiver and thereby the heat pipe and heater tube will be subjected to variable heat input. The design of the heater must be such that it can accommodate the thermal and hydraulic variations that will be imposed upon it.
Date: October 1, 1987
Creator: Parekh, M.B.
Partner: UNT Libraries Government Documents Department

Thermocline Thermal Storage Test for Large-Scale Solar Thermal Power Plants

Description: Solar thermal-to-electric power plants have been tested and investigated at Sandia National Laboratories (SNL) since the late 1970s, and thermal storage has always been an area of key study because it affords an economical method of delivering solar-electricity during non-daylight hours. This paper describes the design considerations of a new, single-tank, thermal storage system and details the benefits of employing this technology in large-scale (10MW to 100MW) solar thermal power plants. Since December 1999, solar engineers at Sandia National Laboratories' National Solar Thermal Test Facility (NSTTF) have designed and are constructing a thermal storage test called the thermocline system. This technology, which employs a single thermocline tank, has the potential to replace the traditional and more expensive two-tank storage systems. The thermocline tank approach uses a mixture of silica sand and quartzite rock to displace a significant portion of the volume in the tank. Then it is filled with the heat transfer fluid, a molten nitrate salt. A thermal gradient separates the hot and cold salt. Loading the tank with the combination of sand, rock, and molten salt instead of just molten salt dramatically reduces the system cost. The typical cost of the molten nitrate salt is $800 per ton versus the cost of the sand and rock portion at $70 per ton. Construction of the thermocline system will be completed in August 2000, and testing will run for two to three months. The testing results will be used to determine the economic viability of the single-tank (thermocline) storage technology for large-scale solar thermal power plants. Also discussed in this paper are the safety issues involving molten nitrate salts and other heat transfer fluids, such as synthetic heat transfer oils, and the impact of these issues on the system design.
Date: August 14, 2000
Creator: ST.LAURENT,STEVEN J.
Partner: UNT Libraries Government Documents Department

Progress toward achieving a commercially viable solar reflective material

Description: Solar thermal technologies use large mirrors to concentrate sunlight for renewable power generation. The development of advanced reflector materials is important to the viability of electricity production by solar thermal energy systems. The reflector materials must be low in cost and maintain high specular reflectance for extended lifetimes under severe outdoor environments. Production processes associated with candidate materials must be scalable to mass production techniques. A promising low-cost construction uses a stainless steel foil substrate with a silver reflective layer protected by an optically transparent oxide topcoat. Thick (2 to 4 micron), dense alumina coatings provide durable protective layers. The excellent performance of alumina-coated reflector materials in outdoor and accelerated testing suggests that a larger field trial of the material is warranted. The key to producing a greater quantity of material for field deployment and testing without incurring substantial capital is the use of a chilled drum coater. An existing chamber is being modified, and the deposition rate will be increased prior to the installation of a drum coater to produce 1-ft wide by 10-ft long strips of solar reflector material. The production and performance of these materials are discussed.
Date: June 1, 1998
Creator: Kennedy, C.E. & Smilgys, R.V.
Partner: UNT Libraries Government Documents Department

The Department of Energy`s Solar Industrial Program: 1995 review

Description: During 1995, the Department of Energy`s Solar Industrial (SI) Program worked to bring the benefits of solar energy to America`s industrial sector. Scientists and engineers within the program continued the basic research, applied engineering, and economic analyses that have been at the heart of the Program`s success since its inception in 1989. In 1995, all three of the SI Program`s primary areas of research and development--solar detoxification, advanced solar processes, and solar process heat--succeeded in increasing the contribution made by renewable and energy-efficient technologies to American industry`s sustainable energy future. The Solar Detoxification Program develops solar-based pollution control technologies for destroying hazardous environmental contaminants. The Advanced Solar Processes Program investigates industrial uses of highly concentrated solar energy. The Solar Process Heat Program conducts the investigations and analyses that help energy planners determine when solar heating technologies--like those that produce industrial-scale quantities of hot water, hot air, and steam--can be applied cost effectively. The remainder of this report highlights the research and development conducted within in each of these subprograms during 1995.
Date: April 1, 1996
Partner: UNT Libraries Government Documents Department

Software and codes for analysis of concentrating solar power technologies.

Description: This report presents a review and evaluation of software and codes that have been used to support Sandia National Laboratories concentrating solar power (CSP) program. Additional software packages developed by other institutions and companies that can potentially improve Sandia's analysis capabilities in the CSP program are also evaluated. The software and codes are grouped according to specific CSP technologies: power tower systems, linear concentrator systems, and dish/engine systems. A description of each code is presented with regard to each specific CSP technology, along with details regarding availability, maintenance, and references. A summary of all the codes is then presented with recommendations regarding the use and retention of the codes. A description of probabilistic methods for uncertainty and sensitivity analyses of concentrating solar power technologies is also provided.
Date: December 1, 2008
Creator: Ho, Clifford Kuofei
Partner: UNT Libraries Government Documents Department

A long-term strategic plan for development of solar thermal electric technology

Description: Solar thermal electric (STE) technologies--parabolic troughs, power towers, and dish/engine systems--can convert sunlight into electricity efficiently and with minimum effect on the environment. These technologies currently range from developmental to early commercial stages of maturity. This paper summarizes the results of a recent strategic planning effort conducted by the US department of Energy (DOE) to develop a long-term strategy for the development of STE technologies. The planning team led by DOE included representatives from the solar thermal industry, domestic utilities, state energy offices, and Sun{center_dot}Lab (the cooperative Sandia National laboratories/National Renewable Energy Laboratory partnership that supports the STE Program) as well as project developers. The plan was aimed at identifying specific activities necessary to achieve the DOE vision of 20 gigawatts of installed STE capability by the year 2020. The planning team developed five strategies that both build on the strengths of, and opportunities for, STE technology and address weaknesses and threats. These strategies are to: support future commercial opportunities for STE technologies; demonstrate improved performance and reliability of STE components and systems; reduce STE energy costs; develop advanced STE systems and applications; and address nontechnical barriers and champion STE power. The details of each of these strategies are discussed.
Date: June 1, 1997
Creator: Williams, T.A.; Burch, G.; Chavez, J.M.; Mancini, T.R. & Tyner, C.E.
Partner: UNT Libraries Government Documents Department

The solar thermal report. Volume 3, Number 5

Description: This report is published by the Jet Propulsion Laboratory for the DOE Solar Thermal Technology Division to provide an account of work sponsored by the Division and to aid the community of people interested in solar thermal technology in gaining access to technical information. Contents include articles entitled the following: Solar system supplies thermal energy for producing chemicals at USS plant; Solar thermal power module designed for small community market; Roof-mounted trough system supplies process heat for Caterpillar plant; Solar thermal update -- 10 MW(e) pilot plant and 3-MW(t) total energy system; Solar steam processes crude oil; New York investigates solar ponds as a source of thermal energy; On-farm solar -- Finding new uses for the sun; and Topical index of solar thermal report articles.
Date: September 1, 1982
Partner: UNT Libraries Government Documents Department

Solar dynamic heat pipe development and endurance test. Monthly technical progress report number 6, 29 October--November 30, 1987

Description: The Space Station requires a high level of reliable electric power. The baseline approach is to utilize a hybrid system in which power is provided by photovoltaic arrays and by solar dynamic power conversion modules. The organic Rankine cycle (ORC) engine is one approach to solar dynamic conversion. The ORO provides the attributes of high efficiency at low temperature and compact simple designs utilizing conventional techniques and materials. The heat receiver is one area which must be addressed in applying the proven ORC to long life applications such as the Space Station. Heat pipes with integral thermal energy storage (TES) canisters and a toluene heater tube are the prime components of the heat receiver from the Phase B preliminary design. This contract is a task order type addressing the design, fabrication and testing of a full scale heat pipe. The contract was initiated on April 16, 1987. Sundstrand has specific responsibilities in each task. Los Alamos National Laboratory (LANL) in turn has the prime contract responsibility to NASA-LeRC.
Date: December 7, 1987
Creator: Parekh, M.B.
Partner: UNT Libraries Government Documents Department

Solar dynamic heat pipe development and endurance test. Monthly technical progress report number 5, 30 September--28 October, 1987

Description: The Space Station requires a high level of reliable electric power. The baseline approach is to utilize a hybrid system in which power is provided by photovoltaic arrays and by solar dynamic power conversion modules. The organic Rankine cycle (ORC) engine is one approach to solar dynamic conversion. The ORC provides the attributes of high efficiency at low temperature and compact simple designs utilizing conventional techniques and materials. The heat receiver is one area which must be addressed in applying the proven ORC to long life applications such as the Space Station. Heat pipes with integral thermal energy storage (TES) canisters and a toluene heater tube are the prime components of the heat receiver from the Phase B preliminary design. This contract is a task order type addressing the design, fabrication and testing of a full scale heat pipe. The contract was initiated on April 16, 1987. Sundstrand has specific responsibilities in each task. Los Alamos National Laboratory (LANL) in turn has the prime contract responsibility to NASA-LeRC.
Date: October 28, 1987
Creator: Parekh, M.B.
Partner: UNT Libraries Government Documents Department

Solar dynamic heat pipe development and endurance test. Monthly technical progress report number 4, August 28--September 29, 1987

Description: The Space Station requires a high level of reliable electric power. The baseline approach is to utilize a hybrid system in which power is provided by photovoltaic arrays and by solar dynamic power conversion modules. The organic Rankine cycle (ORC) engine is one approach to solar dynamic conversion. The ORC provides the attributes of high efficiency at low temperature and compact simple designs utilizing conventional techniques and materials. The heat receiver is one area which must be addressed in applying the proven ORC to long life applications such as the Space Station. Heat pipes with integral thermal energy storage (TES) canisters and a toluene heater tube are the prime components of the heat receiver from the Phase B preliminary design. This contract is a task order type addressing the design, fabrication and testing of a full scale heat pipe. The contract was initiated on April 16, 1987. Sundstrand has specific responsibilities in each task. Los Alamos National Laboratory (LANL) in turn has the prime contract responsibility to NASA-LeRC.
Date: September 29, 1987
Creator: Parekh, M.B.
Partner: UNT Libraries Government Documents Department

Batteries for solar energy systems -- A program at Sandia National Laboratories

Description: DOE has selected Sandia National Laboratories as its lead laboratory to direct a program to develop and test batteries for electrical storage in a variety of solar applications. Initial emphasis is on storage in photovoltaic systems, but wind-energy and solar-thermal systems will be considered later. The BSSAP program is divided functionally into five tasks: Task 1--battery requirements analysis; Task 2--laboratory evaluation; Task 3--PV advanced systems tests; Task 4--applied experiments; Task 5--battery research and development. This report briefly discusses these tasks.
Date: December 31, 1981
Partner: UNT Libraries Government Documents Department

A model library of solar thermal electric components for the computer code TRNSYS

Description: A new approach to modeling solar thermal electric plants using the TRNSYS simulation environment is discussed. The TRNSYS environment offers many advantages over currently used tools, including the option to more easily study the hybrid solar/fossil plant configurations that have been proposed to facilitate market penetration of solar thermal technologies. A component library developed for Rankine cycle, Brayton cycle, and solar system modeling is presented. A comparison between KPRO and TRNSYS results for a simple Rankine cycle show excellent correlation.
Date: July 1, 1998
Creator: Pitz-Paal, R. & Jones, S.
Partner: UNT Libraries Government Documents Department

Solar dish/engine systems

Description: Solar dish/engine systems convert the energy from the sun into electricity at a very high efficiency. Using a mirror array formed into the shape of a dish, the solar dish focuses the sun's rays onto a receiver. The receiver transmits the energy to an engine that generates electric power. Because of the high concentration ratios achievable with parabolic dishes and the small size of the receiver, solar dishes are efficient at collecting solar energy at very high temperatures. Tests of prototype systems and components at locations throughout the US have demonstrated net solar to electric conversion efficiencies as high as 30%. This is significantly higher than any other solar technology.
Date: April 1, 1998
Partner: UNT Libraries Government Documents Department

Solar repowering workshop: a summary report

Description: The workshop was divided into two groups. Group A discussed key issues in the demand for solar thermal technologies; Group B discussed key issues in the supply of solar thermal technologies. Discussion questions prepared prior to the workshop are listed and the responses are summarized. The workshop agenda and the list of participants are included. (MHR)
Date: August 2, 1978
Creator: Nordman, D.
Partner: UNT Libraries Government Documents Department

SOLSTEP: a computer model for predicting the thermodynamic and economic performance of solar thermal power plants

Description: A thermodynamic and economic performance analysis code, SOLSTEP, was developed to facilitate the evaluation of solar thermal power plant designs. The code conducts a time step simulation of the plant thermodynamic performance using actual recorded meteorological and insolation data. Each analysis case provides capacity factor and levelized energy cost results for several plant configurations using various combinations of collector field size and storage capacity. The code has been used to analyze a variety of solar thermal generic concepts involving several collector types and energy conversion and storage subsystems.
Date: May 1, 1979
Creator: Bird, S. P.
Partner: UNT Libraries Government Documents Department

Worker health and safety in solar thermal power systems. IV. Routine failure hazards

Description: Routine failure events in selected solar thermal power system designs are examined, and their rates of occurrence estimated. The results are used to compare and rank the systems considered. Modules of 1 to 100 MWe are developed based on reference or other near-term designs. Technologies used include parabolic trough, parabolic dish, and central tower focusing; central and distributed power generation; and proximate and independent siting of power modules. Component counts and failure rates estimated include heat transfer system leaks, sensor failures, and mechanical and electrical component failures, such as pumps, motors, and wire and cable. Depending on the technology chosen, leak rates can approach 1000 per year per 100 MWe system capacity, while component failure rates can be several times that level. Within categories of failures, the various technologies can have rates differing by a factor of 1000 or more. A uniform weighting for the consequences of the various failure types is proposed. Under this weighting, central tower systems are most favored, followed by parabolic trough, parabolic dishes with dispersed power generation, and parabolic dishes with central power generation. This weighting does not account for possible variations in the technologies. A sensitivity analysis is used to bound the relative hazards of the various failure events required to invert one or more of the system rankings.
Date: September 1, 1979
Creator: Ullman, A.Z.; Sokolow, B.B.; Hill, J.; Meunier, G. & Busick, H. III
Partner: UNT Libraries Government Documents Department