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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Space photovoltaic modules based on reflective optics

The conceptual design and experimental results for two types of space application concentrator photovoltaic modules, employing reflective optical elements, are presented. The first type is based on the use of compound parabolic concentrators, the second type is based on the use of line-focus parabolic troughs. Lightweight concentrators are formed with nickel foil coated silver with a diamond-like carbon layer protection. Secondary optical elements, including lenses and cones, are introduced for a better matching of concentrators and solar cells. Both types of modules are characterized by concentration ratios in the range 20x to 30x, depending on the chosen range of misorientation angles. The estimated specific parameters of these modules operating with single junction AlGaAs/GaAs solar cells are 240 W/sq m and 3 kg/sq m.

Andreev, V. M.↗
NASA NTRS2004

Russian Activities in Space Photovoltaic Power Modules with Concentrators

Space concentrator modules with point-and line-focus Fresnel lenses and with reflective parabolic troughs have been developed recently at Ioffe Physico-Technical Institute. PV receivers for these modules are based: on the single junction LPE and MOCVD AlGaAs/GaAs solar cells characterized by AM0 efficiencies of 23.5 - 24% at 20 - 50 suns and 24 - 24.75 at 50 - 200 suns; on the mechanically stacked tandem AlGaAs/GaAs-GaSb cells with efficiency of 27 - 28 at 20 - 100 suns. MOCVD AlGaAs/GaAs cells with internal Bragg reflector have shown a higher radiation resistance as compared to a traditional structure. Monolithic two-terminal tandems AlGaAs (top)-GaAs (bottom) for space application and GaSb (top) - InGaAsSb (bottom) for TRV application are under development as well.

Andreev, Vyacheslav M.↗
NASA NTRS2013

Low-Cost, Light Weight, Thin Film Solar Concentrator

This research addresses a cost barrier towards achieving a solar thermal collector system with an installed cost of $75/sq m and meet the Department of Energy's (DOE's) performance targets for optical errors, operations during windy conditions and lifetime. Current concentrators can cost as much as 40-50% of the total installed costs for a CSP plant. In order to reduce the costs from current $200-$250/sq m, it is important to focus on the overall system. The reflector surface is a key cost driver, and our film-based polymer reflector will help significantly in achieving DOE's cost target of $75/sq m. The ease of manufacturability, installation and replacement make this technology a compelling one to develop. This technology can be easily modified for a variety of CSP options including heliostats, parabolic dishes and parabolic troughs.

Concentrating Solar Power (CSP)↗
DOE OSTI2013

Cleanable and Hardcoat Coatings for Increased Durability of Silvered Polymeric Mirrors

We have successfully developed coating formulations which significantly increasethe abrasion resistance of mirror films. We have demonstrated manufacturing scale-up of these films to full width andproduction volumes. Implementation of these films in commercial test sites is planned for Q2 2013(Abengoa, Gossamer Space Frames). This slide show outlines the background and objectives of the project, technical approach and results, and key lessons. It also presents the need and opportunity for reduction of costs for CSP and collectors. It also presents an approach for a large aperture parabolic trough collector with reflective film and a high concentration factor, including demonstration and results.

14 SOLAR ENERGY↗
DOE OSTI2017

Solar concentrator with asymmetric tracking-integrated optics

A method is provided for using asymmetrically focused photovoltaic conversion in a hybrid parabolic trough solar power system. Light rays received in a plurality of transverse planes are concentrated towards a primary linear focus in an axial plane, orthogonal to the transverse planes. T band wavelengths of light are transmitted to the primary linear focus, while R band wavelengths of light are reflected towards a secondary linear focus in the axial plane. The light received at the primary linear focus is translated into thermal energy. The light received at the secondary linear focus is asymmetrically focused along a plurality of tertiary linear foci, orthogonal to the axial plane. The focused light in each tertiary linear focus is concentrated into a plurality of receiving areas and translated into electrical energy. Asymmetrical optical elements are used having an optical input interfaces elongated along rotatable axes, orthogonal to the axial plane.

Wheelwright, Brian↗
DOE OSTI2019

Asymmetric tracking-integrated optics for solar concentration

A method is provided for using asymmetrically focused photovoltaic conversion in a hybrid parabolic trough solar power system. Light rays received in a plurality of transverse planes are concentrated towards a primary linear focus in an axial plane, orthogonal to the transverse planes. T band wavelengths of light are transmitted to the primary linear focus, while R band wavelengths of light are reflected towards a secondary linear focus in the axial plane. The light received at the primary linear focus is translated into thermal energy. The light received at the secondary linear focus is asymmetrically focused along a plurality of tertiary linear foci, orthogonal to the axial plane. The focused light in each tertiary linear focus is concentrated into a plurality of receiving areas and translated into electrical energy. Asymmetrical optical elements are used having an optical input interfaces elongated along rotatable axes, orthogonal to the axial plane.

Wheelwright, Brian↗
DOE OSTI2021

Opportunities for Solar Industrial Process Heat in the United States

This presentation summarizes the first national analysis of opportunities for solar technologies to provide industrial process heat (IPH) in the United States. The industrial sector is a major end-user of energy and IPH constitutes a majority of industrial fuel energy. New disaggregations of IPH demands are made at the temporal, geographic, and operational levels. Solar heat generation by seven solar thermal technologies and PV-connected electrotechnologies are modeled using county solar resources and land availability and matched to relevant IPH demands. Parabolic trough collectors (PTC), when combined with thermal energy storage (TES), not only have the largest opportunity in terms of distribution over geography and time, but also in terms of applicable IPH demands. PTC with TES represents the displacement of nearly 2,500 trillion Btus of combustion fuels, which corresponds to 137 million metric tons of CO2, or about 15% of all industrial combustion CO2 emissions. TES, along with site-level analysis, are identified as areas of further analysis.

41 EE - Solar Energy Technologies Office (EE-4S)↗
DOE OSTI2022

CSP Optical Facilities at the National Renewable Energy Laboratory

The concentrating Solar Power (CSP) Optical Facilities at NREL comprise unique optical tools and facilities for testing and characterizing concentrating solar optical components. These facilities are maintained to aid researchers and industry efforts to reduce market barriers, improve the performance, reduce the cost, and improve the lifetime and reliability of CSP materials, components, subsystems, and integrated concepts, where accurate and timely characterization methods are needed. To reach this goal, NREL is committed to collaborating in ongoing and projected research needs for industry, academia, and government entities, in the development and characterization of low-cost, high-performance reflector and absorber materials in addition to their components-a key element in the conversion of concentrated sunlight into energy. To accomplish this mission, the core laboratory includes the Advanced Optical Materials Laboratory, indoor and outdoor accelerated weather testing tools, "Distant Observer" for parabolic troughs, the High Flux Solar Furnace, and the ultra-accelerated weather testing tools. This equipment enables to rapidly respond to new challenges with novel solutions that align with the goals of the Solar Energy Technology Office (SETO) at the U.S. Department of Energy. The goal of this paper is to present the state-of art-optical facilities available at NREL that can help support the research needs of the CSP community. Therefore, we review here the different components of the CSP Optical Facilities at NREL and highlight their characteristics and importance for the CSP community.

accelerated weather testing↗
DOE OSTI2023

A New Reflected Target Optical Assessment System - Stage 1 Development Results: Preprint

NREL has completed stage 1 development of an indoor optical measurement tool for fully assembled heliostats and single facets. This tool began as an indoor version of NREL's NIO technique. It uses similar techniques to other available tools (deflectometry, photogrammetry, etc.), but is designed require very little infrastructure, labor, and time to set up and collect surface slope and canting measurements on fully assembled heliostats and parabolic trough facets, making it a valuable tool for quality assurance and laboratory measurement of helio-stat optics. It accomplishes this by using computer vision, photogrammetry, and multiple images stitched together to minimize the printed target size and required setup precision. This adaptable setup is useful for taking measurements at a variety of heliostat pointing angles, and for measuring fully assembled heliostats on the assembly line. The measurement system's methodology and an analysis of its uncertainty, sensitivity and comparison with established optical measurement systems is described below.

canting↗
NASA NTRS2006

Lightweight, low-cost solar energy collector

A lightweight solar concentrator of the reflecting parabolic or trough type is realized via a thin reflecting film, an inflatable structural housing and tensioned fibers. The reflector element itself is a thin, flexible, specularly-reflecting sheet or film. The film is maintained in the parabolic trough shape by means of a plurality of identical tensioned fibers arranged to be parallel to the longitudinal axis of the parabola. Fiber ends are terminated in two identical spaced anchorplates, each containing a plurality of holes which lie on the desired parabolic contour. In a preferred embodiment, these fibers are arrayed in pairs with one fiber contacting the front side of the reflecting film and the other contacting the back side of the reflecting film. The reflective surface is thereby slidably captured between arrays of fibers which control the shape and position of the reflective film. Gas pressure in the inflatable housing generates fiber tension to achieve a truer parabolic shape.

Hochberg, Eric B.↗
DOE OSTI2019

Dynamic simulation and techno-economic analysis of a concentrated solar power (CSP) plant hybridized with both thermal energy storage and natural gas

The addition of thermal energy storage and natural gas as a complementary energy source improves the flexibility, reliability, and value of concentrated solar power (CSP) plants. Nevertheless, due to the transient nature of solar energy, transitions from solar-only mode and natural-gas mode to hybrid solar-natural gas mode is quite challenging, especially when the plant is equipped with thermal storage. Thus, it is important to develop proper dynamic modeling and control schemes to accurately simulate such transitions. The objective of this study is to address this subject by demonstrating a dynamic model with reliable control schemes for a highly integrated hybrid parabolic trough-natural gas plant equipped with thermal energy storage. The specific goal is to study the dynamics of adding thermal storage to the hybrid plant. It is found that the developed control schemes assist smooth transitions between different operational modes and effective utilization of thermal storage and natural gas to maintain steady power production and steam mass flow rates under different solar conditions. The results demonstrate that the integration of storage regulates power production by solar energy and natural gas during the day time. It also enables an increase in the solar fraction of the hybrid plant while it causes a small decrease in thermodynamic efficiency. The analysis shows that the hybrid plant with the storage has a substantially lower specific CO 2 emission (0.320 tonne/MWh) than single natural gas plant (0.413 tonne/MWh) although it has a higher levelized cost of electricity (86.32/MWh against 74.92/MWh). The hybrid plant with storage demonstrates a promising potential for reliable and clean production of electricity, although research and development should be conducted to lower its cost.

03 NATURAL GAS↗
DOE OSTI2013

Development and evaluation of a prototype concentrating solar collector with thermocline based thermal energy storage for residential thermal usage

A prototype of a concentrating solar collector (CSC) receiver was designed, built, and evaluated on-sun at the University of Texas at El Paso in El Paso, TX. This prototype receiver consists of two parabolic trough-reflectors but, in principle, the design can be efficiently extended to multiple units for achieving a higher temperature throughput. Each reflector has a vacuum tube collector at the focal point of the trough. The solar collector system was combined with a single-tank thermocline thermal energy storage (TES) for off-solar thermal usage. The main goal of this study is to develop an advanced solar hot water system for most residential applications. The focus of this study is to investigate the feasibility and performance of the solar thermal system by employing the recent advancement in the TES—a thermocline based TES—system for the concentrating solar power technologies developed by the Sandia National Laboratories and National Renewable Energy Laboratories for electricity production. A CSC when combined with TES has potential to provide uninterrupted thermal energy for most residential usages. This paper presents a detailed description of prototype design and materials required. The thermal energy storage tank utilizes an insulated 170 l (45 gal) galvanized steel tank. In order to maintain thermocline in the TES tank, with hot water on top and cold water at the bottom, two plate distributors are installed in the tank. The data showed a significant enhancement in thermal energy generation. This thermocline based single tank presented a thermal energy storage potential for at least three days (with diminishing storage capacity) that test were performed. The whole prototype was made for approximately USD 355 (excludes any labor costs) and hence also has strong potential for supplying clean thermal energy in most developing countries. As a result, tests of the prototype were conducted in November 2011.

14 SOLAR ENERGY↗
DOE OSTI2017

Solar Field Optical Characterization at Stillwater Geothermal/Solar Hybrid Plant

Concentrating solar power (CSP) can provide additional thermal energy to boost geothermal plant power generation. For a newly constructed solar field at a geothermal power plant site, it is critical to properly characterize its performance so that the prediction of thermal power generation can be derived to develop an optimum operating strategy for a hybrid system. In the past, laboratory characterization of a solar collector has often extended into the solar field performance model and has been used to predict the actual solar field performance, disregarding realistic impacting factors. In this work, an extensive measurement on mirror slope error and receiver position error has been performed in the field by using the optical characterization tool called Distant Observer (DO). Combining a solar reflectance sampling procedure, a newly developed solar characterization program called FirstOPTIC and public software for annual performance modeling called System Advisor Model (SAM), a comprehensive solar field optical characterization has been conducted, thus allowing for an informed prediction of solar field annual performance. The paper illustrates this detailed solar field optical characterization procedure and demonstrates how the results help to quantify an appropriate tracking-correction strategy to improve solar field performance. In particular, it is found that an appropriate tracking-offset algorithm can improve the solar field performance by about 15%. The work here provides a valuable reference for the growing CSP industry.

14 SOLAR ENERGY↗
DOE OSTI2012

Renewable Electricity Generation (Fact Sheet)

This document highlights DOE's Office of Energy Efficiency and Renewable Energy's advancements in renewable electricity generation technologies including solar, water, wind, and geothermal.

14 SOLAR ENERGY↗
DOE OSTI2022

Full-Scale Hydrogen Mitigation Installation and Testing at Nevada Solar One

This project was performed under a Cooperative Research & Development Agreement (CRADA) between the National Renewable Energy Laboratory (NREL) and Acciona Energy USA (AE). The purpose was to advance an NREL TRL 3 technology that was developed during the previous CRADA from completed laboratory testing to full-scale process installation and testing at AE's Nevada Solar One (NSO) power plant. The project's objective was to complete full-scale implementation and performance verification of the NREL hydrogen mitigation technology at the Nevada Solar One (NSO) power plant in Boulder City, Nevada.

08 HYDROGEN↗
DOE OSTI2023

FY19-FY21 Concentrating Solar Power Systems Analysis Final Report

This technical report summarizes work done by NREL over a 3-year period for the Concentrating Solar Power (CSP) Systems Analysis project for fiscal years 2019-2021 (FY19-FY21) in support of the Solar Energies Technology Office of the U.S. Department of Energy. The goal of the CSP Systems Analysis project is to provide timely and accurate CSP cost data to the U.S. Department of Energy's (DOE's) Solar Energy Technologies Office (SETO) and to project the performance and cost of emerging CSP technologies to inform research directions and industry investment.

14 SOLAR ENERGY↗