Thin film PV modules for low-concentrating systems

The high cost of photovoltaic (PV) energy has imposed extensive research ef forts in order to provide alternatives to the conventional crystalline sili con (c-Si) PV technology. Thin film PV modules based on Cu(In,Ga)Se-2 (CIGS ) is considered one of the most promising alternatives for mass production of low-cost PV. In parallel to the development of new module technologies, there is an increasing interest for using concentrating optics in PV system s in order to increase radiation onto the modules. By replacing the relativ ely expensive PV absorbers with low-cost concentrators there is a potential reduction of overall system costs. The reflector types considered in this study are based on the compound parabolic concentrator (CPC) and the planar reflector. These are low-concentrating devices with concentration ratios o f 1-4. With the CPC as well as the planar reflector, the illumination on th e PV module will be non-uniform, with local light intensities that are cons iderably larger than the average 4 suns, For conventional c-Si modules, thi s is detrimental to module performance. It is demonstrated in the present w ork that modules based on thin film technology are better candidates for re flector applications, The principles of design and fabrication of CIGS thin film PV modules for low-concentrating systems are discussed, and experimen tal results from measurements of CIGS modules under concentrated illuminati on are evaluated. (C) 2001 Elsevier Science Ltd. All rights reserved.