Development of solar panel system for thermally annealing radiation damaged solar cells Final report
Solar panel system for thermally annealing radiation damaged solar cells
Source record↗
SEARCH · Engineering Papers
Results for “Thermal solar”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Site participation in the small community experiment
The Small Community Solar Thermal Experiment, planned to test a small, developmental solar thermal power plant in a small community application, is assessed. The baseline plan is to install a field of parabolic dishes with distributed generation to provide 1 MWe of experimental power. Participation by the site proposer is an integral element of the experiment; the proposer will provide a ten-acre site, a connection to the electrical distributional system serving the small community, and various services. In addition to the primary participant, site study efforts may be pursued at as many as five alternative sites.
Holbeck, H. J.↗
High Flux Microchannel Receiver Development (Final Report)
The opportunity addressed in this project was using microscale heat exchanger technology for improving solar thermal central receiver efficiency. This will result in smaller, less expensive components and reduce the levelized cost of electricity from concentrated solar thermal power. This micro-pin solar receiver (MSR) directly heats high pressure (25 MPa) supercritical carbon dioxide (sCO 2 ) from 550°C to 720°C with an incident flux of at least 120 W/cm 2 at a receiver efficiency of >90% (assuming availability of 95% absorptivity coating), and receiver cost target of less than $\$$150/kWt. Realization of the MSR required an understanding of thermal hydraulic performance of sCO 2 in micro-pin passages, mechanical behavior of high nickel alloys at high temperatures including joints, advanced fabrication methods of high nickel alloys (etching, machining, brazing, welding, diffusion bonding), and the cost implications of these when the concept is scaled to production volumes. The technology can be used with gases (sCO 2 , helium, etc.) or with liquids such as molten salt or liquid metal. Given the high pressure associated with sCO 2 , its use demonstrates a “worst case” scenario, and the successful development of the MSR for this application will result in the development of a technology also applicable to a range of other heat transfer fluids that will enable next generation CSP plants, including support of the Gen3CSP program.
14 SOLAR ENERGY↗
Integration of Concentrating Solar Power with High Temperature Electrolysis for Hydrogen Production: Preprint
Hydrogen (H2) has been identified as a leading sustainable contender to replace fossil fuels in transportation and electricity generation. H2 production can be achieved by concentrating solar thermal power (CSP) systems collecting thermal energy from the sun to various chemical processes for fuel production. Fuel production via solar thermal chemical processes integrated with CSP uses the full spectrum of sunlight compared with photovoltaic power conversion and stores solar energy directly and efficiently [1]. The solar fuel production can be realized by thermochemical processes (e.g., water splitting for H2 production, carbon dioxide reduction, or methane reforming) or thermal electrochemical methods (e.g., integration with solid oxide electrolysis cell). Technology development for CSP-integrated solar fuel production requires broad technological bases from solar energy collection to chemical energy conversion. H2 generated from renewable sources can be an energy carrier for a carbon-free economy. Integrating CSP with high temperature electrolysis (HTE) using solid oxide electrolysis cells (SOEC) provides a renewable path for H2 generation. The CSP-HTE integration approach provides the benefit of thermal energy storage (TES) for continuous operation, improved capacity, and SOEC life. H2 gas has low energy density for transportation, pipeline networks are expensive, and H2 liquefaction is energy intensive. However, an alternative method for H2 distribution is to use carbon dioxide (CO2) capture and liquid hydrocarbon synthesis to convert solar energy into liquid fuels that are compatible with the existing fossil fuel infrastructure.
concentrating solar thermal power↗
Thermal control of a solar sail
Thermal control concepts for the square and the heliogyro solar sail designs under consideration for a Halley's Comet rendezvous mission are presented. The mission, involving a 1982 launch, navigation to a 0.25-AU cranking orbit about the sun in order to develop a retrograde orbit, and rendezvous with the comet in 1986, would subject surfaces of the sail vehicle to solar constant values ranging from 16 to 0.1. A highly reflective coating to produce propulsive force is needed for one surface of the sail, while the other surface requires a highly emittive coating. The problem of maintaining the sail wrinkle-free is discussed.
Stimpson, L. D.↗
Solar Probe thermal shield design and testing
This paper discusses the major thermal shield subsystem development activities in support of the Solar Probe study being conducted at JPL. The Solar Probe spacecraft will travel to within 4 solar radii of the sun's center to perform fundamental experiments in space physics. Exposure to 2900 earth suns at perihelion requires the spacecraft to be protected within the shadow envelope of a protective shield. In addition, the mass loss rate off of the shield at elevated temperature must comply with plasma instrument requirements and has become the driver of the shield design. This paper will focus on the analytical design work to size the shield and control the shield mass loss rate for the various spacecraft options under study, the application of carbon-carbon materials for shield components, development and preparation of carbon-carbon samples for materials testing, and a materials testing program for carbon-carbon and tungsten alloys to investigate thermal/optical properties, mass loss (carbon-carbon only), material integrity, and high velocity impact behavior.
Millard, Jerry M.↗
Transparent Refractory Aerogels for Efficient Spectral Control in High–Temperature Solar Power Generation
Although spectrally selective materials play a key role in existing and emerging solar thermal technologies, temperature-related degradation currently limits their use to below 700 °C in vacuum and even lower temperatures in air. Here a solar-transparent refractory aerogel that offers stable performance up to 800 °C in air is demonstrated, which is significantly greater than its silica counterpart. This improved stability is attributed to the formation of a refractory aluminum silicate phase, which is synthesized using a conformal single cycle of atomic layer deposition within the high-aspect-ratio pores of silica aerogels. Furthermore, based on direct heat loss measurements, the transparent refractory aerogel achieves a receiver efficiency of 75% at 100 suns and an absorber temperature of 700 °C, which is a 5% improvement over the state of the art. Transparent refractory aerogels may find widespread applicability in solar thermal technologies by enabling the use of lower-cost optical focusing systems and eliminating the need for highly evacuated receivers. In particular, a shift to higher operating temperatures while maintaining a high receiver efficiency can enable the use of advanced supercritical CO 2 power cycles and ultimately translate to an ≈10% (absolute) improvement in solar-to-electrical conversion efficiency relative to existing linear concentrating systems.
14 SOLAR ENERGY↗
Design, Fabrication and Test of a High Efficiency Refractive Secondary Concentrator for Solar Applications
Common to many of the space applications that utilize solar thermal energy such as electric power conversion, thermal propulsion, and furnaces, is a need for highly efficient, solar concentration systems. An effort is underway to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the effort at the NASA Glenn Research Center to evaluate the performance of a prototype single crystal sapphire refractive secondary concentrator and to compare the performance with analytical models. The effort involves the design and fabrication of a secondary concentrator, design and fabrication of a calorimeter and its support hardware, calibration of the calorimeter, testing of the secondary concentrator in NASA Glenn's Tank 6 solar thermal vacuum facility, and comparing the test results with predictions. Test results indicate an average throughput efficiency of 87%. It is anticipated that reduction of a known reflection loss with an anti-reflective coating would result in a secondary concentrator throughput efficiency of approximately 93%.
Wong, Wayne A.↗
Concentrated solar photovoltaic and photothermal system
The present invention provides a hybrid, concentrating photovoltaic-solar thermal (CPV/T) system and components thereof, and methods for converting solar energy to electricity at high efficiencies while capturing and storing solar thermal energy for later deployment.
Codd, Daniel↗
Solar wind thermal electrons from 1.15 to 5.34 AU - Ulysses observations
Using unique 3-d velocity space measurements by the Ulysses solar wind plasma experiment from 1.15 to 5.34 AU, we assess the radial gradient in thermal electron temperature. Until 3.8 AU, the gradient was steeper than previously reported but flatter than adiabatic; after 3.8 AU the gradient flattened. Trends in the observed electron distribution shapes qualitatively support predictions for regulation by Coulomb collisions and by expansion in a spiral IMF.
Phillips, J. L.↗
Heliostat Observation System Commercialization Qualification HOS-C-Q (Final Technical Report)
Heliostat fields are one of the main components of a concentrated solar thermal plant. As GEN3 technology has been developed at pilot plant level targeting higher temperatures >700C, having a precise Heliostat field control system will enable the success of the GEN3 technology. Heliogen Inc. has developed the next generation of control systems for heliostat fields. Their early development was on single facet heliostats at their R&D facility in Lancaster, California. This new system allows for a closed loop integration to a current open loop setup of a regular Heliostat control system. Sandia National Laboratories and Heliogen Inc. have partnered together to test Heliogen’ s innovative new SOHOT system at the National Solar Thermal Test Facility.
14 SOLAR ENERGY↗
Evaluation of Additively Manufactured Monolithic SiC and SiC Ceramic Matrix Composites for Concentrating Solar Receiver Applications
Supported by an award from the Solar Technology Office, US Department of Energy, GE Aerospace Research in collaboration with Heliogen Holdings Inc, is engaged in the development of ultra-High Operating Temperature SiC-matrix Solar Thermal Air Receiver (HOTSSTAR). We report the results of our study of the effective heat transfer characteristic of several candidate structure motifs, or feature geometries, made of SiC via additive manufacturing in a simulative laboratory test. The SiC structure motifs studied include different permutations of three-dimensional periodic lattices and defined shapes. The solar-thermal simulating laboratory test setup is constructed using a 4kW CO2 laser system with beam shaping optics to apply radiative heating power on one face of 2”-diameter cylindrical feature specimens representing the structure motifs of interest for receiver element design. Using the test setup, simulative test conditions representative of a concentrated solar flux of up to ~2000 suns could be achieved in the lab tests under varying air flow through the test structure. A numerical analysis scheme is developed to extract an effective or compound heat transfer coefficient representative of the test structure under steady-state heat flow conditions.
14 SOLAR ENERGY↗
Low-cost desalination of seawater and hypersaline brine using nanophotonics enhanced solar energy membrane distillation
A stand-alone small-scale nanophotonics enhanced solar membrane distillation (NESMD) testbed was designed, developed, and tested for desalinating seawater and high salinity feedwaters. This NESMD system can take almost any source water and turn it into clean water with sunlight as the only energy source. The NESMD technology applies nanophotonic coating materials on a commercial hydrophobic polypropylene support of a polytetrafluoroethylene (PTFE) membrane surface. The photothermal coating serves as a solar thermal collector, absorbs solar energy, and generates highly localized heat on the membrane, while the rest of the membrane performs membrane distillation functions. The presented NESMD system is equipped with an internal heat recovery system with no need for external electricity and no additional water for cooling. The NESMD testbed is installed and tested at Rice University campus (29.7174° N, 95.4018° W). In this study, real seawater from Galveston Bay, Texas, U.S. and high salinity simulated feedwaters (total dissolved solids (TDS) of 113 200–200 000 PPM) have been tested for long-term testing under the weather conditions of Houston, Texas. Here, the field testing results showed stable desalination performance in consecutive 5–8 hour operation cycles, with a TDS removal of ≥99.5% in all experiments. An average daily membrane flux of ≥0.75 L m –2 h –1 was achieved at a solar intensity close to 1 kW m –2 without an external heat exchanger. Further investigations and improvements are required to enhance the performance of the reactor since it is still a new promising technology.
14 SOLAR ENERGY↗
Thermal storage for electric utilities
Applications of the thermal energy storage (TES) principle (storage of sensible heat or latent heat, or heat storage in reversible chemical reactions) in power systems are evaluated. Load leveling behind the meter, load following at conventional thermal power plants, solar thermal power generation, and waste heat utilization are the principal TES applications considered. Specific TES examples discussed include: storage heaters for electric-resistance space heating, air conditioning TES in the form of chilled water or eutectic salt baths, hot water TES, and trans-seasonal storage in heated water in confined aquifers.
Swet, C. J.↗
Comparative assessment of orbital and terrestrial central power plants
Recent studies of the space power system (SPS) are integrated into a total social cost framework developed for terrestrial central electric power systems. Total social costs include the projection of commercial economics to the time frame of interest as well as the federal research, development and demonstration (RD&D) costs, the health impacts, the resources required, the environmental impacts and other social costs. The SPS system is limited to transporting all materials from the earth's surface to geosynchronous orbit. Only silicon photovoltaic is considered as the SPS energy conversion technique. Costs and impacts of the LWR are considered as a reference for nuclear systems, and the low BTU coal gasification with combined cycle gas and steam turbines is considered as a reference for a fossil central electric plant. The ground solar systems considered are solar thermal using the central receiver approach with thermal storage, and solar photovoltaic using the silicon cell with battery storage.
Caputo, R.↗
Space transportation systems, 1980-2000
An overview of projected space transportation systems for the 1980-2000 period is presented. Methods for meeting the requirements in that area are documented through a description of the Space Shuttle and its current upper stages, reusable transfer vehicles, Shuttle uprating, fully reusable and single-stage transports, heavy lift vehicles, and advanced vehicles for orbital transfer and lunar landing. The structure of the liquid oxygen/liquid hydrogen boosters, cryogenic propellants, whose main propulsion system is a derivative of the RL-10 engine used in the Centaur launch, and mixed mode propulsion engine is also described, as is the flyback booster concept and such related issues as propellants and rocket engines, staging velocity, configuration shape, and whether it should be manned or unmanned. Especially noted are proposed propulsion systems going beyond the present Shuttle such as the nuclear and electric propulsion concepts, the resistojet, using liquid hydrogen, ion thruster, using argon, magnetoplasmadynamic thrusters, solar thermal rocket, and solar sail concept where the basic idea is to use a 'sail' of thin reflective material to generate a net force by reflection of solar radiation.
Cohan, C. J.↗
Dynamics and control of Stirling engines in a 15 kWe solar electric generation concept
This paper discusses the application of kinematic and free piston Stirling engines in a 15 kWe dish-electric approach for solar thermal electric generation. Initially, the principle of operation of Stirling engines in solar thermal electric generation is discussed. Then, under certain simplifying assumptions, mathematical models describing the dynamic operation of the kinematic and free piston Stirling engines are developed. It is found that the engine dynamics may be approximated by second order models. Control mechanisms for both types of Stirling engines are discussed. An approach based on the modulation of the working fluid mean pressure is presented. It is concluded that this approach offers a fast and effective means of control. The free piston Stirling engine, being a thermally driven mechanical oscillator, presents unique control requirements. These are discussed in this paper.
Das, R. L.↗
Spectroscopic Behavior of Composite, Black Thermal Paint, Solar Cell, and Multi-layered Insulation Materials in a GEO Simulated Environment
Materials currently populating Earth orbital regimes can be distinguished by comparing remote observational data to that of optical material measurements obtained in the laboratory. Experimentation for this research primarily involved the acquisition of spectroscopic measurements on materials of interest to the telescopic observational community for enhanced space situational awareness. Common spacecraft materials worthy of preeminent analysis for this investigation include a carbon-carbon (c-c) matrix composite, various black thermal paints, a GPS solar cell and three different cover glass components. These materials were subjected to a simulated geosynchronous Earth orbit (GEO) space environment with the intent of observing material optical property behavior over quantitative exposure time. The aforementioned materials have been measured in their pristine and GEO simulated exposed conditions. A reflectance spectrometer and a bi-directional reflectance distribution function (BRDF) optical system have been operated to perform material characterization, optical property analysis, and to further compare such data to telescopic observational data acquired on equal materials.
Reyes, Jacqueline A.↗