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Title: Solar reflector

Abstract

A solar reflector having a flexible triangular reflective sheet or membrane for receiving and reflecting solar energy therefrom. The reflector is characterized by the triangular reflective sheet which is placed under tension thereby defining a smooth planar surface eliminating surface deflection which heretofore has reduced the efficiency of reflectors or heliostats used in combination for receiving and transmitting solar energy to an absorber tower.

Inventors:
Publication Date:
OSTI Identifier:
6427895
Patent Number(s):
US 4251135
Assignee:
IFI; EDB-81-097994
Resource Type:
Patent
Resource Relation:
Patent File Date: Filed date 7 May 1979
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; SOLAR REFLECTORS; DESIGN; EFFICIENCY; ROTATION; SHEETS; STRESSES; SUPPORTS; EQUIPMENT; MECHANICAL STRUCTURES; MOTION; SOLAR CONCENTRATORS; SOLAR EQUIPMENT; 141000* - Solar Collectors & Concentrators

Citation Formats

Stone, D. C.. Solar reflector. United States: N. p., 1981. Web.
Stone, D. C.. Solar reflector. United States.
Stone, D. C.. Tue . "Solar reflector". United States. doi:.
@article{osti_6427895,
title = {Solar reflector},
author = {Stone, D. C.},
abstractNote = {A solar reflector having a flexible triangular reflective sheet or membrane for receiving and reflecting solar energy therefrom. The reflector is characterized by the triangular reflective sheet which is placed under tension thereby defining a smooth planar surface eliminating surface deflection which heretofore has reduced the efficiency of reflectors or heliostats used in combination for receiving and transmitting solar energy to an absorber tower.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Feb 17 00:00:00 EST 1981},
month = {Tue Feb 17 00:00:00 EST 1981}
}
  • A prismatic plate is mounted with its flat face exposed to the sun on a reflector panel for use in a solar energy collection system. The plate includes a plurality of triangular prisms with parallel longitudinal axes shaped to provide total internal reflection of incident light rays. Each prism has a cross section forming a right-angled isosceles triangle with the two equal-length, rear faces of the prism oriented at 45 degrees relative to the front face of the plate. The base of each prism forms or is parallel to a front plate surface which receives incident solar light rays. Themore » rays are transmitted through the plate cross section without refraction in the plane of the cross section to be reflected from the two rear faces and back out the front face toward a solar receiver. The prism material has an index of refraction equal to or greater than the square root of two so that there is total internal reflection from the prism faces. The prismatic plate is mounted on a movable heliostat panel controlled by a tracking system to reflect to a solar receiver. The panel has a fixed axis directed toward a central receiver and a moving axis orthogonal to the fixed axis. The prismatic plate is mounted on the panel with the longitudinal axes of the prisms perpendicular to the moving axis. Tracking is accomplished by adjusting the panel orientation so that the plane of incidence of the incident solar rays is parallel to the longitudinal axes of the prisms and also so that the reflected solar rays intercept the receiver.« less
  • A photovoltaic module comprising an array of electrically interconnected photovoltaic cells disposed in a planar and mutually spaced relationship between a light-transparent front cover member in sheet form and a back sheet structure is provided with a novel light-reflecting means disposed between adjacent cells for reflecting light falling in the areas between cells back toward said transparent cover member for further internal reflection onto the solar cells. The light-reflecting comprises a flexible plastic film that has been embossed so as to have a plurality of small V-shaped grooves in its front surface, and a thin light-reflecting coating on said frontmore » surface, the portions of said coating along the sides of said grooves forming light-reflecting facets, said grooves being formed so that said facets will reflect light impinging thereon back into said transparent cover sheet with an angle of incidence greater than the critical angle, whereby substantially all of the reflected light will be internally reflected from said cover sheet back to said solar modules, thereby increasing the current output of the module.« less
  • A passive solar system is disclosed having a plurality of heat storage trays mounted adjacent to a window and arranged to absorb relatively low angled radiation and to reject relatively high angled radiation while providing a substantially unobstructed view through the window. The trays have their reflective upper surfaces angled toward the window and their absorptive lower surfaces angled toward the room. A phase change heat storage material is disposed between the upper and lower surfaces. In one configuration the lower surface is corrugated having one set of generally absorptive surface faces facing the reflective upper surface of an adjacentmore » tray and having another set of generally emissive surface faces facing the interior of the room.« less
  • This invention is concerned with reducing the operating temperature and increasing the output of a solar cell. A solar cell constructed in accordance with the invention carries electrodes in a grid finger pattern on its back surface. These electrodes are sintered at the proper temperature to provide good ohmic contact. After sintering, a reflective material is deposited on the back surface by vacuum evaporation. Thus, the application of the back surface reflector is separate from the back contact formation. Back surface reflectors formed in conjunction with separate grid finger configuration back contacts are more effective than those formed by fullmore » back metallization of the reflector material.« less
  • A system is described for supporting a plurality of reflective surfaces in an arrangement for reflecting the rays emitted from a source of energy and converging the reflected rays to concentrate the heating effect thereof at a receptor, whereby a plurality of pairs of long tension members extend under tension between firmly anchored support members. Reflecting elements are supported by the pairs of tension members and each of the pairs is disposed to reflect the radiation from substantially all of the reflecting elements to the receptor.