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An assessment of second-generation stretched-membrane mirror modules

01 Feb 1990-Vol. 90, pp 22841
TL;DR: The first 50m{sup 2} mirror modules, built under contract to Sandia in 1986, demonstrated that membrane heliostats could perform at least as well as glass mirrors as discussed by the authors.
Abstract: For more than 10 years, the US Department of Energy's Solar Thermal Program has pioneered the development of heliostats, mirrors that track the sun, for solar central-receiver power plants. The field of heliostats is the single most expensive part of such plants, so their cost must be as low as possible for the technology to be commercially successful. Recent efforts have focused on the development of heliostats that use stretched-membrane reflectors in place of the more familiar glass mirrors. In such heliostats, metal foils are stretched over both sides of a large-diameter metal ring. The reflective surface is a silvered-polymer film glued to the front membrane. A slight vacuum in the space between the two membranes is actively controlled to provide a concave, focused contour to the mirror, and in an emergency this space can be rapidly pressurized to defocus it. Because of their simplicity and lighter weight, stretched- membrane heliostats have the potential to cost significantly less than current glass-mirror designs. The first 50-m{sup 2} mirror modules, built under contract to Sandia in 1986, demonstrated that membrane heliostats could perform at least as well as heliostats using glass mirrors. Insights gained from Sandia's testing and evaluation of the first-generationmore » units were incorporated into the designs of two improved 50-m{sup 2} mirror modules. The results of Sandia's evaluation show significant improvement in optical performance over the first-generation designs, especially in windy conditions. 22 refs., 29 figs.« less
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Journal ArticleDOI
TL;DR: The U.S. Department of Energy's solar concentrator development program in a joint effort with the Solar Energy Research Institute is described in this article, where the status and future plans of DOE's program in each area are reviewed.

14 citations

Journal ArticleDOI
TL;DR: In the last six years, Sandia National Laboratories has been developing and transferring to private industry a technology that uses stretched-membrane reflectors in place of the more familiar glass mirrors as mentioned in this paper.

4 citations

Journal Article
TL;DR: In the last six years, Sandia National Laboratories has been developing and transferring to private industry a technology that uses stretched-membrane reflectors in place of the more familiar glass mirrors as mentioned in this paper.
Abstract: For more than 10 years, the US Department of Energy's Solar Thermal Program has pioneered the development of heliostats, mirrors that track the sun, for solar central-receiver power plants. The field of heliostats is the single most expensive part of such plants, so their cost must be as low as possible for the technology to be commercially successful. In the last six years, Sandia National Laboratories has been developing and transferring to private industry a technology that uses stretched-membrane reflectors in place of the more familiar glass mirrors. Because of their simplicity and lighter weight, stretched-membrane heliostats have the potential to cost significantly less than current glass-mirror designs. Two generations of 50 m 2 prototype stretched-membrane mirror modules were evaluated at Sandia's National Solar Thermal Test Facility in Albuquerque, NM. They demonstrated an optical performance rivaling that of the more familiar glass-mirror heliostats. Sandia recently initiated the final phase of development: the design of fully integrated, market-ready heliostats. Field tests are planned for late 1990.

4 citations