Facet development for a faceted stretched-membrane dish by Solar Kinetics, Inc

Technical Report · Mon Jul 01 04:00:00 EDT 1991

DOI:https://doi.org/10.2172/5526862· OSTI ID:5526862

Schertz, P. T.; Brown, D. C.; Konnerth, A. III ^[1]

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1. Solar Kinetics, Inc., Dallas, TX (United States)

A 3.6-meter diameter stretched-membrane optical facet for a parabolic dish has been successfully designed and demonstrated under contract with Sandia National Laboratories. Twelve facets identical to them will be used to make the lightweight reflector of the dish. The project goal of 2.5-mrad surface accuracy was met with each of the two full-sized prototypes, and accuracies of as low as 1.1 mrad were achieved. The facet weight is 11.7 kg/m{sup 2} (2.4lbs/ft{sup 2}). The facet is similar in construction to the successful stretched-membrane heliostat; it has two thin metal membranes attached to a ring. However, the front membrane for this facet is plastically formed at the factor in order to achieve a shorter facet f/D (approximately 3.0). A passive tether restrains the from membrane when not in operation, that is, when the stabilizing vacuum is off. The optical surface is achieved with a silvered-acrylic film laminated to the metal membrane. The facet is expected to cost $$55.40/m{sup 2} at a production rate of 10,000 facets per year and $$115, 000/m{sup 2}-at a production rate of 500 facets a year. Several key issues have been resolved. Stress concentrations due to seams in the reflective laminate did not cause membrane rupture during forming as they have for dishes with lower focal length-to-diameter ratios. The laminate survived the forming process and simulated operation without deterioration. The optical effect of the tether on the membrane was tested and found to be very small. Most important, highly accurate shapes were obtained using a simple forming procedure. Additional tests are needed to demonstrate process repeatablility and facet performance in typical operating conditions. 18 refs., 36 figs., 11 tabs.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States); Solar Kinetics, Inc., Dallas, TX (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5526862
• Report Number(s): SAND-91-7009; ON: DE91016866
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors & Concentrators
CONCENTRATING COLLECTORS
COST
CSP
Concentrating Solar Power
DEMONSTRATION PROGRAMS
DESIGN
EQUIPMENT
MEMBRANES
OPTICAL PROPERTIES
PARABOLIC COLLECTORS
PARABOLIC DISH COLLECTORS
PHYSICAL PROPERTIES
REFLECTIVITY
SOLAR COLLECTORS
SOLAR CONCENTRATORS
SOLAR EQUIPMENT
SOLAR REFLECTORS
SPECIFICATIONS
STRESSES
SURFACE PROPERTIES