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Results for “SOLAR POWER SYSTEM”

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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Megawatt solar power systems for lunar surface operations

The work presented here shows that a solar power system can provide power on the order of one megawatt to a lunar base with a fairly high specific power. The main drawback to using solar power is still the high mass, and therefore, cost of supplying energy storage through the solar night. The use of cryogenic reactant storage in a fuel cell system, however, greatly reduces the total system mass over conventional energy storage schemes.

Adams, B.↗
NASA NTRS1976

A comparison of GaAs and Si hybrid solar power systems

An analytical comparison of energy output from various silicon and gallium arsenide hybrid solar power systems, producing electric power and also thermal power for heating or cooling, is made. System performance indices in terms of capital cost, peak power, total power output, and electric power were evaluated. Limiting values for annual energy production from GaAs and Si solar concentrator systems were estimated to be 2 cents and 6.8 cents per kWh for GaAs concentrator systems and between 2.5 cents and 11 cents per kWh for Si concentrator systems.

Heinbockel, J. H.↗
NASA NTRS2003

GPS-Like Phasing Control of the Space Solar Power System Transmission Array

The problem of phasing of the Space Solar Power System's transmission array has been addressed by developing a GPS-like radio navigation system. The goal of this system is to provide power transmission phasing control for each node of the array that causes the power signals to add constructively at the ground reception station. The phasing control system operates in a distributed manner, which makes it practical to implement. A leader node and two radio navigation beacons are used to control the power transmission phasing of multiple follower nodes. The necessary one-way communications to the follower nodes are implemented using the RF beacon signals. The phasing control system uses differential carrier phase relative navigation/timing techniques. A special feature of the system is an integer ambiguity resolution procedure that periodically resolves carrier phase cycle count ambiguities via encoding of pseudo-random number codes on the power transmission signals. The system is capable of achieving phasing accuracies on the order of 3 mm down to 0.4 mm depending on whether the radio navigation beacons operate in the L or C bands.

Psiaki, Mark L.↗
NASA NTRSDate not supplied

A Comparison of Radioisotope and Solar Array/Battery Power Systems in the Solar System

Radioisotope Power Systems (RPS) are an invaluable resource for the exploration of our solar system. Providing both heat and electricity, spacecraft using RPS can operate where its impractical to use solar array and/or battery systems because of either limited solar illumination or mission durations which make a standalone battery impractical. This paper highlights the performance advantages which may come from using a RPS compared with a solar array/battery system. Included in this paper is an overview of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), the Next-Generation RTG (NGRTG) and Dynamic Radioisotope System (DRPS). State-the-Art (SOA) performance of solar arrays and batteries is discussed. Finally, a comparison of both solar cell/battery systems compare with RPS are made at a variety of locations, both orbital and on the surface of some planets and their moons within our solar system.

Paul C Schmitz↗
NASA NTRSDate not supplied

A Comparison of Radioisotope and Solar Array/Battery Power Systems in the Solar System

Radioisotope Power Systems (RPS) are an invaluable resource for the exploration of our solar system. Providing both heat and electricity, spacecraft using RPS can operate where its impractical to use solar array and/or battery systems because of either limited solar illumination or mission durations which make a standalone battery impractical. This paper highlights the performance advantages which may come from using a RPS compared with a solar array/battery system. Included in this paper is an overview of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), the Next-Generation RTG (NGRTG) and Dynamic Radioisotope System (DRPS). State-the-Art (SOA) performance of solar arrays and batteries is discussed. Finally, a comparison of both solar cell/battery systems compare with RPS are made at a variety of locations, both orbital and on the surface of some planets and their moons within our solar system.

Paul C Schmitz↗
NASA NTRSDate not supplied

A Comparison of Radioisotope and Solar Array/Battery Power Systems in the Solar System

Radioisotope Power Systems (RPS) are an invaluable resource for the exploration of our solar system. Providing both heat and electricity, spacecraft using RPS can operate where its impractical to use solar array and/or battery systems because of either limited solar illumination or mission durations which make a standalone battery impractical. This paper highlights the performance advantages which may come from using a RPS compared with a solar array/battery system. Included in this paper is an overview of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), the Next-Generation RTG (NGRTG) and Dynamic Radioisotope System (DRPS). State-the-Art (SOA) performance of solar arrays and batteries is discussed. Finally, a comparison of both solar cell/battery systems compare with RPS are made at a variety of locations, both orbital and on the surface of some planets and their moons within our solar system.

Paul Schmitz↗
NASA NTRS1981

Development of the small community solar power system

The status of the Small Community Solar Thermal Power Experiment is presented. Activities on the Phase 2 single/module development effort are presented, together with plans for the Phase 3 1 MWe demonstration plant. A description of the various subsystems and components is given with emphasis on the unmanned microprocessor based plant control subsystem. Latest performance figures are given for the 1 MWe plant, based on 56 power modules, each consisting of a 12m low cost concentrator, a cavity receiver, a Rankine power conversion subsystem and a ground mounted solid-state rectifier. Overall plant efficiency at rated conditions is 15.8 percent. Advanced glass concentrator designs yield 20 percent overall efficiencies.

Babbe, R. H.↗
NASA NTRS1990

Megawatt solar power systems for lunar surface operations

Lunar surface operations require habitation, transportation, life support, scientific, and manufacturing systems, all of which require some form of power. As an alternative to nuclear power, the development of a modular one megawatt solar power system is studied, examining both photovoltaic and dynamic cycle conversion methods, along with energy storage, heat rejection, and power backup subsystems. For photovoltaic power conversion, two systems are examined. First, a substantial increase in photovoltaic conversion efficiency is realized with the use of new GaAs/GaSb tandem photovoltaic cells, offering an impressive overall array efficiency of 23.5 percent. Since these new cells are still in the experimental phase of development, a currently available GaAs cell providing 18 percent efficiency is examined as an alternate to the experimental cells. Both Brayton and Stirling cycles, powered by linear parabolic solar concentrators, are examined for dynamic cycle power conversion. The Brayton cycle is studied in depth since it is already well developed and can provide high power levels fairly efficiently in a compact, low mass system. The dynamic conversion system requires large scale waste heat rejection capability. To provide this heat rejection, a comparison is made between a heat pipe/radiative fin system using advanced composites, and a potentially less massive liquid droplet radiator system. To supply power through the lunar night, both a low temperature alkaline fuel cell system and an experimental high temperature monolithic solid-oxide fuel cell system are considered. The reactants for the fuel cells are stored cryogenically in order to avoid the high tankage mass required by conventional gaseous storage. In addition, it is proposed that the propellant tanks from a spent, prototype lunar excursion vehicle be used for this purpose, therefore resulting in a significant overall reduction in effective storage system mass.

Adams, Brian↗
NASA NTRS1981

The effect of concentrator field layout on the EE-1 small community solar power system

The point-focusing distributed receiver (PFDR) concept is employed by a number of solar thermal power systems currently under development. One type of PFDR system which shows particular promise incorporates distributed energy generation. According to this concept each parabolic dish collector is a self-contained power generation module, and a conventional electrical system is used to interconnect the modules. The concept is thus modular, and any number of power modules can be combined to achieve the required plant size. Given the benefits of mass production, it appears that this type of system can produce electricity at lower cost than is projected for conventional (fossil) power systems over the next decade. An employment of organic Rankine cycle heat engines is considered.

Pons, R. L.↗
NASA NTRS1999

Solar Power System Analyses for Electric Propulsion Missions

Solar electric propulsion (SEP) mission architectures are applicable to a wide range of NASA missions including human Mars exploration and robotic exploration of the outer planets. In this paper, we discuss the conceptual design and detailed performance analysis of an SEP stage electric power system (EPS). EPS performance, mass and area predictions are compared for several PV array technologies. Based on these studies, an EPS design for a 1-MW class, Human Mars Mission SEP stage was developed with a reasonable mass, 9.4 metric tons, and feasible deployed array area, 5800 sq m. An EPS was also designed for the Europa Mapper spacecraft and had a mass of 151 kg and a deployed array area of 106 sq m.

Kerslake, Thomas W.↗
NASA NTRS1966

Photovoltaic power systems.

Solar photovoltaic power systems weight reduction and reliability noting applicability to propulsion, attitude control and stationkeeping missions

Goldsmith, J.↗
NASA NTRS1977

Space solar power systems

Studies were done on the feasibility of placing a solar power station called POwersat, in space. A general description of the engineering features are given as well as a brief discussion of the economic considerations.

Toliver, C.↗
NASA NTRS1985

Controlling Solar-Power Systems With Distributed Processors

System undergoing development uses distributed microprocessors to monitor and control photovoltaic power system. Equipment increases life expectancy and reliability of power system and decreases costs. Adapted to vehicular, residential, and commercial solar and nonsolar power systems. Equipment especially desirable in systems with overall power levels above few kilowatts.

Imamura, M. S.↗
NASA NTRS1982

Development status of the small community solar power system

The development status and test results for the Small Community Solar Thermal Power Experiment are presented. Activities on the phase 2 power module development effort are presented with emphasis on the receiver, the plant control subsystem, and the energy transport subsystem. The components include a single prototype power module consisting of a parabolic dish concentrator, a power conversion assembly (PCA), and a multiple-module plant control subsystem. The PCA consists of a cavity receiver coupled to an organic Rankine cycle engine-alternator unit defined as the power conversion subsystem; the PCA is mounted at the focus of a parabolic dish concentrator. At a solar insolation of 100 W/sq m and ambient temperature of 28 C (82 F), the power module produces approximately 20 kW of 3-phase, 3 kHz ac power, depending on the concentrator employed. A ground-mounted rectifier to the central collection site where it is supplied directly to the common dc bus which collects the power from all modules in the plant.

Pons, R. L.↗
NASA NTRS1989

Tracing Rays In A Solar Power System

OFFSET is ray-tracing computer code for analysis of optics of solar collector. Code models distributions of solar flux within receiver cavity, produced by reflections from collector. Developed to model mathematically offset solar collector of solar dynamic electric power system being developed for Space Station Freedom. Used to develop revised collector-facet concept of four groups of toroidally contoured facets. Also used to develop methods for tailoring distribution of flux incident on receiver. Written in FORTRAN 77 (100 percent).

Jefferies, Kent↗