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Guidelines for reporting parabolic trough solar electric system performance

Description: The purpose of this activity is to develop a generic methodology which can be used to track and compare the performance of parabolic trough power plants. The approach needs to be general enough to work for all existing and future parabolic trough plant designs, provide meaningful comparisons of year to year performance, and allow for comparisons between dissimilar plant designs. The approach presented here uses the net annual system efficiency as the primary metric for evaluating the performance of parabolic trough power plants. However, given the complex nature of large parabolic trough plants, the net annual system efficiency by itself does not adequately characterize the performance of the plant. The approach taken here is to define a number of additional performance metrics which enable a more comprehensive understanding of overall plant performance.
Date: June 1, 1997
Creator: Price, H.W.
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

Enhancement of Solar Energy Representation in the GCAM Model

Description: The representation of solar technologies in a research version of the GCAM (formerly MiniCAM) integrated assessment model have been enhanced to add technologies, improve the underlying data, and improve the interaction with the rest of the model. We find that the largest potential impact from the inclusion of thermal Concentrating Solar Power plants, which supply a substantial portion of electric generation in sunny regions of the world. Drawing on NREL research, domestic Solar Hot Water technologies have also been added in the United States region where this technology competes with conventional electric and gas technologies. PV technologies are as implemented in the CCTP scenarios, drawing on NREL cost curves for the United States, extrapolated to other world regions using a spatial analysis of population and solar resources.
Date: February 1, 2010
Creator: Smith, Steven J.; Volke, April C. & Delgado Arias, Sabrina
Partner: UNT Libraries Government Documents Department

Validation of the FLAGSOL parabolic trough solar power plant performance model

Description: This paper describes the results of a validation of the FLAGSOL parabolic trough solar power plant performance model. The validation was accomplished by simulating an operating solar electric generating system (SEGS) parabolic trough solar thermal power plant and comparing the model output results with actual plant operating data. This comparison includes instantaneous, daily, and annual total solar thermal electric output, gross solar electric generation, and solar mode parasitic electric consumption. The results indicate that the FLAGSOL model adequately predicts the gross solar electric output of an operating plant, both on a daily and an annual basis.
Date: October 1, 1994
Creator: Price, H.W.; Svoboda, P. & Kearney, D.
Partner: UNT Libraries Government Documents Department

Improved accuracy for low-cost solar irradiance sensors

Description: Accurate measurements of broadband (full spectrum) solar irradiance are fundamental to the successful implementation of solar power systems, both photovoltaic and solar thermal. Historically, acceptable measurement accuracy has been achieved using expensive thermopile-based pyranometers and pyrheliometers. The measurement limitations and sensitivities of these expensive radiometers are a topic that has been addressed elsewhere. This paper demonstrates how to achieve acceptable accuracy ({+-}3) in irradiance measurements using photodiodes or photovoltaic cells as sensors, and in addition to low-cost, have several operational advantages.
Date: December 31, 1997
Creator: King, D.L.; Boyson, W.E. & Hansen, B.R.
Partner: UNT Libraries Government Documents Department

A comparison of on-axis and off-axis heliostat alignment strategies

Description: Heliostat installation and alignment costs will be an important element in future solar power tower projects. The predicted annual performances of on- and-off axis strategies are compared for 95 m{sup 2} flat-glass heliostats and an external, molten-salt receiver. Actual approaches to heliostat alignment that have been used in the past are briefly discussed, and relative strengths and limitations are noted. The optimal approach can vary with the application.
Date: March 1, 1996
Creator: Jones, S.A.
Partner: UNT Libraries Government Documents Department

Satellite Power Systems (SPS): concept development and evaluation program, preliminary assessment

Description: The Satellite Power System (SPS) is an emerging concept for capturing solar energy in space for use in producing electrical energy on earth. To develop an understanding of the technical and economic feasibility and of the environmental and societal acceptability of the SPS is an enormous challenge. The Department of Energy and the National Aeronautics and Space Administration are engaged in a three-year assessment of the SPS that began in the fall of 1977 and will be completed in the summer of 1980. The DOE/NASA assessment is engaging the efforts of many organizations in the United States and is developing a large body of information. At approximately the mid-point of the assessment, this preliminary project assessment report describes what has been done and what has been learned with an emphasis on the overriding issues.
Date: September 1, 1979
Partner: UNT Libraries Government Documents Department

Assessment of the effects of the zero gravity environment on the health and safety of space workers. Summary report

Description: A review was conducted of currently available information relating to adverse effects to the health and safety that SPS space workers may experience. Currently available information on the responses of humans to space flight is somewhat limited and was obtained under conditions which are grossly different from conditions to be experienced by future space workers. The limitations in information and differences in conditions have been considered in the assessment of potential health and safety hazards to the SPS space workers. The study did not disclose any adverse effects that would result in long term deviations to the medical or physiological health of space workers so long as proper preventive or ameleorating actions were taken.
Date: February 18, 1980
Partner: UNT Libraries Government Documents Department

Some questions and answers about the Satellite Power System (SPS)

Description: The Office of Energy Research, US DOE is evaluating the concept of obtaining significant amounts of electrical energy from space through the Satellite Power System Project Office (SPS PO) formed for that purpose. The SPS PO prepared and is implementing a Concept Development and Evaluation Program plan. The CDEP runs roughly three years (from July 1977 through July 1980) and consists of four primary elements: (1) Systems Definition, (2) Environmental Assessment, (3) Societal Assessment, and (4) Comparative Assessment. One facet of the Societal Assessment is an investigation of public concerns. To further this investigation, a public outreach experiment was initiated to determine the initial response of three selected interest groups to the SPS, both qualitatively and quantititavely, and to gain some experience for use in future public participation activities. Three groups were contacted and agreed to participate in the experiment. They were: the Citizens Energy Project (CEP), the Forum for the Advancement of Students in Science and Technology (FASST), and the L-5 Society (L-5). They each agreed to condense twenty final SPS reports into approximately four pages each, have them typeset, printed and distributed to 3,000 of their constituents for their review, together with a request that they respond to the parent organization regarding the information presented. All responses were summarized and provided to Planning Research Corporation who then solicited the answers from the SPS PO investigator most directly concerned.The questions and answers are presented and will be distributed by the three groups to the individual respondents. Each of the three groups is also preparing a report to the Project Office detailing their work and results. These, together with other responses and studies will be used to more effectively involve the public in the SPS Participatory Technology Process.
Date: January 1, 1980
Partner: UNT Libraries Government Documents Department

SPS energy conversion and power management workshop. Final report

Description: In 1977 a four year study, the concept Development and Evaluation Program, was initiated by the US Department of Energy and the National Aeronautics and Space Administration. As part of this program, a series of peer reviews were carried out within the technical community to allow available information on SPS to be sifted, examined and, if need be, challenged. The SPS Energy Conversion and Power Management Workshop, held in Huntsville, Alabama, February 5 to 7, 1980, was one of these reviews. The results of studies in this particular field were presented to an audience of carefully selected scientists and engineers. This first report summarizes the results of that peer review. It is not intended to be an exhaustive treatment of the subject. Rather, it is designed to look at the SPS energy conversion and power management options in breadth, not depth, to try to foresee any troublesome and/or potentially unresolvable problems and to identify the most promising areas for future research and development. Topics include photovoltaic conversion, solar thermal conversion, and electric power distribution processing and power management. (WHK)
Date: June 1, 1980
Partner: UNT Libraries Government Documents Department

Workshop on Satellite Power Systems (SPS) effects on optical and radio astronomy

Description: The impacts of the SPS on astronomy were concluded to be: increased sky brightness, reducing the effective aperture of terrestrial telescopes; microwave leakage radiation causing erroneous radioastronomical signals; direct overload of radioastronomical receivers at centimeter wavelengths; and unintentional radio emissions associated with massive amounts of microwave power or with the presence of large, warm structures in orbit causing the satellites to appear as individual stationary radio sources; finally, the fixed location of the geostationary satellite orbits would result in fixed regions of the sky being unusable for observations. (GHT)
Date: April 1, 1980
Creator: Stokes, G.M. & Ekstrom, P.A. (eds.)
Partner: UNT Libraries Government Documents Department

Satellite power system (SPS) public outreach experiment

Description: To improve the results of the Satellite Power System (SPS) Concept Development and Evaluation Program, an outreach experiment was conducted. Three public interest groups participated: the L-5 Society (L-5), Citizen's Energy Project (CEP), and the Forum for the Advancement of Students in Science and Technology (FASST). Each group disseminated summary information about SPS to approximately 3000 constituents with a request for feedback on the SPS concept. The objectives of the outreach were to (1) determine the areas of major concern relative to the SPS concept, and (2) gain experience with an outreach process for use in future public involvement. Due to the combined efforts of all three groups, 9200 individuals/organizations received information about the SPS concept. Over 1500 receipients of this information provided feedback. The response to the outreach effort was positive for all three groups, suggesting that the effort extended by the SPS Project Division to encourage an information exchange with the public was well received. The general response to the SPS differed with each group. The L-5 position is very much in favor of SPS; CEP is very much opposed and FASST is relatively neutral. The responses are analyzed, and from the responses some questions and answers about the satellite power system are presented in the appendix. (WHK)
Date: December 1, 1980
Creator: McNeal, S.R.
Partner: UNT Libraries Government Documents Department

Satellite Power Systems (SPS) space transportation cost analysis and evaluation

Description: The objective of this study is to provide a clear picture of SPS space transportation costs at the present time with respect to their accuracy as stated, the reasonableness of the methods used, the assumptions made, and the uncertainty associated with the estimates. The approach used consists of examining space transportation costs from several perspectives - to perform a variety of sensitivity analyses or reviews and examine the findings in terms of internal consistency and external comparison with analogous systems. These approaches are summarized as a theoretical and historical review including a review of stated and unstated assumptions used to derive the costs, and a performance or technical review. These reviews cover the overall transportation program as well as the individual vehicles proposed. The review of overall cost assumptions is the principal means used for estimating the cost uncertainty derived. The cost estimates used as the best current estimate are included.
Date: November 1, 1980
Partner: UNT Libraries Government Documents Department

Search of archived data sources for rocket exhaust-induced modifications of the ionosphere

Description: The emergence of the Satellite Power System (SPS) concept as a way of augmenting the dwindling energy sources available for commercial power usage involved such a large and unprecendented technological program that detailed assessment and feasibility studies were undertaken in an attempt to specify the true impact such a program would have. As part of the issues addressed, a comprehensive environmental impact study was initiated that involved an unprecedented scope of concerns ranging from ground-level noise and weather modifications to possible planetary-scale perturbations caused by SPS activity in distant Earth orbits. This report describes results of a study of an intermediate region of the Earth's environment (the ionosphere) where large-scale perturbations are caused by routine rocket activity. The SPS program calls for vast transportation demands into and out from the ionosphere (h approx. = 200 to 1000 km), and thus the well-known effect of chemical depletions of the ionosphere (so-called ionospheric holes) caused by rocket exhaust signaled a concern over the possible large-scale and long-term consequences of the induced effects.
Date: September 1, 1980
Creator: Chacko, C.C. & Mendillo, M.
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

The U.S. Department of Energy`s solar enterprise zone

Description: To demonstrate the commercial viability of producing and marketing solar generated power, the Department of Energy is supporting the construction of a solar facility in the State of Nevada. The purpose of the audit was to determine if the Department had fully examined the costs and benefits of siting a solar facility at the Nevada Test Site and at alternative sites in Nevada.
Date: April 1, 1998
Partner: UNT Libraries Government Documents Department

Vibration test plan for a space station heat pipe subassembly

Description: This test plan describes the Sundstrand portion of task two of Los Alamos National Laboratory (LANL) contract 9-x6H-8102L-1. Sundstrand Energy Systems was awarded a contract to investigate the performance capabilities of a potassium liquid metal heat pipe as applied to the Organic Rankine Cycle (ORC) solar dynamic power system for the Space Station. The test objective is to expose the heat pipe subassembly to the random vibration environment which simulates the space shuttle launch condition. The results of the test will then be used to modify as required future designs of the heat pipe.
Date: September 29, 1987
Creator: Parekh, M. B.
Partner: UNT Libraries Government Documents Department

A nightly conditioning method to reduce parasitic power consumption in molten-salt central-receiver solar-power plants

Description: A method to reduce nightly parasitic power consumption in a molten salt central receiver is discussed where salt is drained from the piping and heat tracing is turned off to allow the piping to cool to ambient overnight, then in the morning the pipes are filled while they are cold. Since the piping and areas of the receiver in a molten-nitrate salt central-receiver solar power plant must be electrically heated to maintain their temperatures above the nitrate salt freezing point (430{degrees}F, 221{degrees}C), considerable energy could be used to maintain such temperatures during nightly shut down and bad weather. Experiments and analyses have been conducted to investigate cold filling receiver panels and piping as a way of reducing parasitic electrical power consumption and increasing the availability of the plant. The two major concerns with cold filling are: (1) how far can the molten salt penetrate cold piping before freezing closed and (2) what thermal stresses develop during the associated thermal shock. Experiments and analysis are discussed.
Date: June 1, 1995
Creator: Pacheco, J.E.
Partner: UNT Libraries Government Documents Department

Heliostat cost reduction study.

Description: Power towers are capable of producing solar-generated electricity and hydrogen on a large scale. Heliostats are the most important cost element of a solar power tower plant. Since they constitute {approx} 50% of the capital cost of the plant it is important to reduce heliostat cost as much as possible to improve the economic performance of power towers. In this study we evaluate current heliostat technology and estimate a price of $126/m{sup 2} given year-2006 materials and labor costs for a deployment of {approx}600 MW of power towers per year. This 2006 price yields electricity at $0.067/kWh and hydrogen at $3.20/kg. We propose research and development that should ultimately lead to a price as low as $90/m{sup 2}, which equates to $0.056/kWh and $2.75/kg H{sup 2}. Approximately 30 heliostat and manufacturing experts from the United States, Europe, and Australia contributed to the content of this report during two separate workshops conducted at the National Solar Thermal Test Facility.
Date: June 1, 2007
Creator: Jones, Scott A.; Lumia, Ronald. (University of New Mexico, Albuquerque, NM); Davenport, Roger (Science Applications International Corporation, San Diego, CA); Thomas, Robert C. (Advanced Thermal Systems, Centennial, CO); Gorman, David (Advanced Thermal Systems, Larkspur, CO); Kolb, Gregory J. et al.
Partner: UNT Libraries Government Documents Department