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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 NTRS1976

Space-based solar power conversion and delivery systems study. Volume 3: Economic analysis of space-based solar power systems

A variety of economic and programmatic issues are discussed concerning the development and deployment of a fleet of space-based solar power satellites (SSPS). The costs, uncertainties and risks associated with the current photovoltaic SSPS configuration, and with issues affecting the development of an economically viable SSPS development program are analyzed. The desirability of a low earth orbit (LEO) demonstration satellite and a geosynchronous (GEO) pilot satellite is examined and critical technology areas are identified. In addition, a preliminary examination of utility interface issues is reported. The main focus of the effort reported is the development of SSPS unit production, and operation and maintenance cost models suitable for incorporation into a risk assessment (Monte Carlo) model (RAM). It is shown that the key technology area deals with the productivity of man in space, not, as might be expected, with some hardware component technology.

Hazelrigg, G. A., Jr.↗
NASA NTRS1983

Advantage of resonant power conversion in aerospace applications

An ultrasonic, sinusoidal aerospace power distribution system is shown to have many advantages over other candidate power systems. These advantages include light weight, ease of fault clearing, versatility in handling many loads including motors, and the capability of production within the limits of present technology. References are cited that demonstrate the state of resonant converter technology and support these conclusions.

Hansen, I. G.↗
NASA NTRSDate not supplied

Stirling Power Conversion for Lunar Applications

NASA is developing Stirling power convertors for use in nuclear power systems that would provide electricity to users on the lunar surface. NASA’s Radioisotope Power Systems (RPS) Program is maturing advanced dynamic convertor technologies that would increase the efficiency beyond the heritage systems for missions to the Moon and other solar system bodies of interest. Development efforts have focus on Stirling and Brayton designs that meet reliability and robustness requirements for operation in the lunar environment. GRC is also maturing low power convertors in the range of 1-40 watts to power micro-spacecraft or a network of distributed probes and include basic demonstration of in-house designs for convertors and controllers. In addition to RPS applications, conceptual fission systems have been demonstrated using Stirling convertors in multiple electrically heated tests and one test heated by a nuclear reactor. The Stirling convertors used in these fission system concepts include 100 We convertors to enable a 1 kWe system, 1 kWe convertors to enable a 10 kWe system, and 6 kWe convertors to enable a 40 kWe system. The maturation of Stirling power convertors for nuclear applications includes verification of performance in relevant environments and validation of the design with a focus on high reliability and robustness. Over 1 million hours of testing has been accumulated on dozens of convertors since 1999 in the Stirling Research Laboratory at the NASA Glenn Research Center located in Cleveland Ohio, where the longest running convertor is the work record holder at 137,000 hours, or 15.5 years. These maturation efforts have been instrumental in increasing the technology readiness level of Stirling technologies for space applications.

S. Wilson↗
NASA NTRS1976

Space-based solar power conversion and delivery systems study

Even at reduced rates of growth, the demand for electric power is expected to more than triple between now and 1995, and to triple again over the period 1995-2020. Without the development of new power sources and advanced transmission technologies, it may not be possible to supply electric energy at prices that are conductive to generalized economic welfare. Solar power is renewable and its conversion and transmission from space may be advantageous. The goal of this study is to assess the economic merit of space-based photovoltaic systems for power generation and a power relay satellite for power transmission. In this study, satellite solar power generation and transmission systems, as represented by current configurations of the Satellite Solar Station (SSPS) and the Power Relay Satellite (PRS), are compared with current and future terrestrial power generation and transmission systems to determine their technical and economic suitability for meeting power demands in the period of 1990 and beyond while meeting ever-increasing environmental and social constraints.

Source record↗
NASA NTRS2000

A Deep Space Power System Option Based on Synergistic Power Conversion Technologies

Deep space science missions have typically used radioisotope thermoelectric generator (RTG) power systems. The RTG power system has proven itself to be a rugged and highly reliable power system over many missions, however the thermal-to-electric conversion technology used was approximately 5% efficient. While the relatively low efficiency has some benefits in terms of system integration, there are compelling reasons why a more efficient conversion system should be pursued. The cost savings alone that are available as a result of the reduced isotope inventory are significant. The Advanced Radioisotope Power System (ARPS) project was established to fulfill this goal. Although it was not part of the ARPS project, Stirling conversion technology is being demonstrated with a low level of funding by both NASA and DOE. A power system with Stirling convertors. although intended for use with an isotope heat source. can be combined with other advanced technologies to provide a novel power system for deep space missions. An inflatable primary concentrator would be used in combination with a refractive secondary concentrator (RSC) as the heat source to power the system. The inflatable technology as a structure has made great progress for a variety of potential applications such as communications reflectors, radiators and solar arrays. The RSC has been pursued for use in solar thermal propulsion applications, and it's unique properties allow some advantageous system trades to be made. The power system proposed would completely eliminate the isotope heat source and could potentially provide power for science missions to planets as distant as Uranus. This paper will present the background and developmental status of the technologies and will then describe the power system being proposed.

Schreiber, Jeffrey G.↗
DOE OSTI2025

Metamorphic Epitaxy Solutions for Thermophotovoltaic and Laser Power Conversion Applications

Metamorphic GaInAs enables photovoltaic devices optimized for a wide range of bandgaps between 0.35 and 1.41 eV. We have developed compositionally graded buffers made of GaInP and AlGaInAs to enable growth of these devices on GaAs substrates with low dislocation densities and high performance. We present results for devices grown on both graded buffer materials with device bandgaps in the range 0.58-1.41 eV and compare the benefits and drawbacks of each material system. These results enable high performance for applications such as thermophotovoltaics and optical power transmission using high power lasers.

III-V↗
NASA NTRS1976

Systems definition space-based power conversion systems

Potential space-located systems for the generation of electrical power for use on Earth are discussed and include: (1) systems producing electrical power from solar energy; (2) systems producing electrical power from nuclear reactors; and (3) systems for augmenting ground-based solar power plants by orbital sunlight reflectors. Systems (1) and (2) would utilize a microwave beam system to transmit their output to Earth. Configurations implementing these concepts were developed through an optimization process intended to yield the lowest cost for each. A complete program was developed for each concept, identifying required production rates, quantities of launches, required facilities, etc. Each program was costed in order to provide the electric power cost appropriate to each concept.

Source record↗
DOE OSTI2020

Hydrokinetic Power Conversion Using Vortex-Induced Oscillation with Cubic Restoring Force

A cubic-spring restoring function with high-deformation stiffening is introduced to passively improve the harnessed marine hydrokinetic power by using flow-induced oscillations/vibrations (FIO/V) of a cylinder. In these FIO/V experiments, a smooth, rigid, single-cylinder on elastic end-supports is tested at Reynolds numbers ranging from 24,000 < Re < 120,000. The parameters of the tested current energy converter (CEC) are cubic stiffness and linear damping. Using the second generation of digital virtual spring-damping (Vck) controller developed by the Marine Renewable Energy Laboratory (MRELab), the cubic modeling of the oscillator stiffness is tested. Experimental results show the influence of the parameter variation on the amplitude, frequency, energy conversion, energy efficiency, and power of the converter. All experiments are conducted in the low turbulence-free surface water (LTFSW) channel of the MRELab of the University of Michigan. The main conclusions are: (1) The nonlinearity in the cubic oscillator is an effective way to extend the vortex-induced vibration (VIV) upper branch, which results in higher harnessing power and efficiency compared to the linear stiffness cylinder converter. (2) Compared to the linear converter, the overall power increase is substantial. The nonlinear power optimum, occurring at the end of the VIV upper branch, is 63% higher than its linear counterpart. (3) The cubic stiffness converter with low harnessing damping achieves consistently good performance in all the VIV regions because of the hardening restoring force, especially at higher flow velocity.

13 HYDRO ENERGY↗