Concentrator PV modules and solar cells for TPV systems

Concentrator technology is considered as a lower cost alternative to the "flat" solar arrays. For high concentration ratios (500 x and higher) the use of high-efficiency III-V solar cells is very promising and can provide reduced cell cost contribution to the cost of an installation. The efficiencies of 25-27% were achieved for the single-junction AlGaAs/GaAs solar cells under 500-1500 suns, AM 1.5d. These cells are applied in the concentrator modules based on a concept of the small-aperture refractive concentrators. A modified structure of the high concentration "all-glass" PV modules with III-V solar cells is proposed. In the "all-glass" module design, the secondary small-aperture smooth surface lenses arranged in an intermediate composite (glass-silicone) panel be inserted between a panel of the primary composite Fresnel lens concentrators and a panel of the solar cells. Such a design allows fabricating the modules of large total area (up to 0.5 x 1 m(2)) and improving environmental protection of the cells. The cells as small as 1.2 mm in designated area diameter operating at very high concentration ratio (more than 1000 x) can be used in the developed solar PV modules. Also, solar thermophotovoltaics (TPV) is discussed and results of the narrow-gap GaSb and GaAs/Ge cell development for TPV receivers are presented. (C) 2004 Elsevier B.V. All rights reserved.