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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Low cost point focus solar concentrator, phase 1

Design concepts and plans for mass-production facilities and equipment, field installation, and maintenance were developed and used for cost analysis of a pneumatically stabilized plastic film point focus solar concentrator which has potential application in conjunction with Brayton cycle engines or supply of thermal energy. A sub-scale reflector was fabricated and optically tested by laser ray tracing to determine focal deviations of the surface slope and best focal plane. These test data were then used for comparisons with theoretical concentrator performance modeling and predictions of full-scale design performance. Results of the economic study indicate the concentrator design will have low cost when mass-produced and has cost/performance parameters that fall within current Jet Propulsion Laboratory goals.

Source record↗
NASA NTRS1993

Lightweight solar concentrator structures, phase 2

This report summarizes the results of the program conducted by Ultramet under SBIR Phase 2 Contract NAS3-25418. The objective of this program was to develop lightweight materials and processes for advanced high accuracy Space Solar Concentrators using rigidized foam for the substrate structure with an integral optical surface.

Williams, Brian E.↗
NASA NTRS1989

Structural concepts for very large (400-meter-diameter) solar concentrators

A general discussion of various types of large space structures is presented. A brief overview of the history of space structures is presented to provide insight into the current state-of-the art. Finally, the results of a structural study to assess the viability of very large solar concentrators are presented. These results include weight, stiffness, part count, and in-space construction time.

Mikulas, Martin M., Jr.↗
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)↗
NASA NTRS1989

Space deployable domed solar concentrator with foldable panels and hinge therefor

A space deployable solar energy concentrator is formed of a dome-shaped arrangement of compactly stowable flat panel segments mounted on a collapsible, space-deployable support structure of interconnected linear components. The support structure is comprised of a plurality of tensioned, curvilinear edge strips which extend in a radial direction from a prescribed vertex of a surrounding umbrella-like framework of radially extending rib members. Between a respective pair of radially-extending, curvilinear edge strips an individual wedge-shaped panel section is formed of a plurality of multi-segment lens panel strips each of which is supported in tension between the pair of edge strips by a pair of circumferentially extending catenary cord members connected to a pair of ribs of the surrounding umbrella-like framework. A respective lens panel strip is comprised of a plurality of flat, generally rectangular-shaped, energy-directing panels arranged side-by-side in the circumferential direction of the dome. Adjacent panels are interconnected by flexible U-shaped hinges which overlap opposing edges of adjacent panels and engage respective cylindrically-shaped, load distribution bars that slide within the flexible hinges. Because each U-shaped hinge is flexible, it is permitted to shift in the circumferential direction of the panel section to facilitate stowage and deployment of the dome.

Grayson, Fred G.↗
NASA NTRS1986

Solar concentrator materials development

Materials with potential applications in reflective and refractive solar dynamic concentrators are tested for resistance to atomic oxygen degradation. It is found that inorganic coatings such as MgF2, SiO(x), and ITO provide excellent protection for reflective surfaces while organic materials are much more susceptible to erosion and mass loss. Of the organic polymers tested, the silicones have the highest intrinsic resistance to atomic oxygen degradation.

Morel, D. E.↗
NASA NTRS1981

Multijunction high voltage concentrator solar cells

The standard integrated circuit technology has been developed to design and fabricate new innovative planar multi-junction solar cell chips for concentrated sunlight applications. This 1 cm x 1 cm cell consisted of several voltage generating regions called unit cells which were internally connected in series within a single chip resulting in high open circuit voltages. Typical open-circuit voltages of 3.6 V and short-circuit currents of 90 ma were obtained at 80 AM1 suns. A dramatic increase in both short circuit current and open circuit voltage with increased light levels was observed.

Valco, G. J.↗
NASA NTRS1979

Test of concentrator solar array model for SEPS

The use of concentrators to improve the performance of solar arrays in deep space was tested in a simulated deep space environment. The results of these tests are presented and discussed. Areas of discussion include cell temperature performance in a low temperature, low illumination environment with and without concentration, concentration ratios, and theoretical analysis versus test results. Tests were conducted on a series/parallel configuration and individual cells.

Huie, H. H.↗
NASA NTRS1980

Flat plate vs. concentrator solar photovoltaic cells - A manufacturing cost analysis

The choice of which photovoltaic system (flat plate or concentrator) to use for utilizing solar cells to generate electricity depends mainly on the cost. A detailed, comparative manufacturing cost analysis of the two types of systems is presented. Several common assumptions, i.e., cell thickness, interest rate, power rate, factory production life, polysilicon cost, and direct labor rate are utilized in this analysis. Process sequences, cost variables, and sensitivity analyses have been studied, and results of the latter show that the most important parameters which determine manufacturing costs are concentration ratio, manufacturing volume, and cell efficiency. The total cost per watt of the flat plate solar cell is $1.45, and that of the concentrator solar cell is $1.85, the higher cost being due to the increased process complexity and material costs.

Granon, L. A.↗
NASA NTRS1989

Thermal annealing of GaAs concentrator solar cells

The thermal annealing of GaAs concentrator cells after electron irradiation is reported. Results are given for cells annealed at 150, 200, and 250 C. Isochronal annealing was done for 20 min intervals up to 350 C. For cells irradiated with electrons of energies between 0.7 and 2.3 MeV, the recovery decreases with increasing electron energy. Isothermal and isochronal annealing produce the same recovery. Cells irradiated to 3 x 10 to the 15th or 1 x 10 to the 16th e/sq cm recover to similar unannealed fractions. Significant annealing is seen starting at 150 C, although very long times are required.

Curtis, H. B.↗
NASA NTRS1983

Multiple-Panel Cylindrical Solar Concentrator

Trough composed of many panels concentrates Sun's energy on solar cells, even when trough is not pointed directly at Sun. Tolerates deviation as great as 5 degrees from direction of sun. For terrestrial applications, multiple-flat-plate design offers potential cost reduction and ease of fabrication.

Brown, E. M.↗
NASA NTRS1987

Design, fabrication and delivery of a miniature Cassegrainian concentrator solar array system

The optical design of the miniature Cassegrainian concentrator (MCC) element was improved for both offpoint and onpoint power capability. The cell stack design has shown no losses under the high short term thermal stresses imposed by component level test and is projected to be capable of greater than five years thermal cycle life in low Earth orbit. The structural design met all requirements for stiffness and flatness and requires adjustable inserts for fine tuning of the GFRP structure to meet flatness goals. The completed, fully populated small and large MCC panels deliverable under this contract perform electrically as expected. A solid acceptance inspection program to guarantee quality of all purchased parts, and continued manufacturing process improvements will make the MCC design a viable low cost alternative to standard flat panel technology. Minor improvements to the cell stack design of the MCC element can make significant improvements in both the performance and manufacturability of the MCC system.

Kruer, Mark A.↗
NASA NTRS1975

Experimental evaluation of a solar concentrator

A program concerned with the development of a large scale solar concentrator/collector subsystem is considered. Distributed collector approaches are related to the use of a parabolic mirror, a Fresnel reflector, and a Fresnel lens. A system description is given, taking into account questions of turbine interface selection and aspects of collector field layout. Performance sensitivity studies on particular components and parameters are discussed along with performance data which have been obtained for parabolic reflector, Fresnel lens, and Fresnel reflector concentrators. Attention is given to details regarding the design, the operation, and the status of development of the collection subsystem which is being developed.

Hastings, L. J.↗
NASA NTRS1980

An adjustable solar concentrator

Fixed cylindrical converging lenses followed by movable parabolic mirror focus solar energy on conventional linear collector. System is low cost and accomodates daily and seasonal movements of the sun. Mirrors may be moved using simple, low-power electrical motors.

Collins, E. R., Jr.↗
NASA NTRS1991

Thermal annealing of GaAs concentrator solar cells

Isochronal and isothermal annealing tests were performed on GaAs concentrator cells which were irradiated with electrons of various energies to fluences up to 1 x 10(exp 16) e/sq cm. The results include: (1) For cells irradiated with electrons from 0.7 to 2.3 MeV, recovery decreases with increasing electron energy. (2) As determined by the un-annealed fractions, isothermal and isochronal annealing produce the same recovery. Also, cells irradiated to 3 x 10(exp 15) or 1 x 10(exp 16) e/sq cm recover to similar un-annealed fractions. (3) Some significant annealing is being seen at 150 C although very long times are required.

Curtis, H. B.↗
NASA NTRS1995

Solar Concentrator Conceptual Design for the /SUS Advanced Technology Demonstration

An Integrated Solar Upper stage would permit such realignment to smaller vehicles but would also change the current expendable stage paradigm to a reusable one. ISUS would remain with the satellite following orbit insertion and function as its electrical power and propulsion subsystems. Since a satellite's power subsystem represents as much as 30% of its total mass, using the upper stage to replace an onboard photovoltaic/battery system will purchase additional mass for sensors and communication packages. The timely demonstration of an ISUS system, before the turn of the century, will permit such devices to be fielded in the early 2000's and in time to fly aboard major satellite block changes.

Charles H. Castle↗