High Efficiency Flexible Photovoltaic Blankets

ABSTRACT: MicroLink will develop a high-efficiency, flexible photovoltaic blanket, which will reduce solider borne weight by reducing battery requirements. The photovoltaic blanket will combine ultra-thin, flexible high-efficiency, GaAs-based multi-junction solar cells, made using MicroLink"s proprietary epitaxial lift-off (ELO) process, with a novel packaging approach that involves laminating arrays of solar cells between two sheets of robust, flexible polymer. The blanket will have efficiency>25% and will generate 80 W in full sun. MicroLink will investigate both dual-junction and triple-junction 20 cm2 cells for use in this application and will select one cell type based on a cost-benefit analysis. If triple-junction solar cells are used, the dimensions of the blanket will be 58 cm x 60 cm. The blanket will contain power-conditioning circuitry such that it will be capable of charging a BB-2950 type battery. This project will result in photovoltaic blankets with high overall efficiency that are capable of being rolled or folded in order to be easily transported by soldiers. The panel construction technique will be adaptable enough that the blanket can be scaled up to ~at least 1,000 W. BENEFIT: The proposed development of photovoltaic blankets will benefit the military in that it will reduce the burden carried in the field by soldiers. The lightweight, efficient, flexible photovoltaic blankets to be developed will replace some or all of the bulky, heavy, expensive, non-rechargeable batteries soldiers currently carry to power their equipment, such as radios and night-vision goggles. Generating electrical power by using photovoltaic blankets will also reduce the amount of fuel and equipment the military logistics train has to transport to forward bases. Lightweight, flexible, high-efficiency photovoltaic blankets of this type are also potentially useful as sources of power in solar-powered aircraft and solar-powered spacecraft applications. There are many potential commercial applications for photovoltaic blankets. There are millions of hikers, campers, and outdoor sportsmen who want to have access to the same entertainment and communications devices they use at home. Photovoltaic blankets could be used to directly power, or to recharge batteries for GPS receivers, phones, and computers. As blanket costs decrease, other applications become feasible: for example, photovoltaic blankets could be built into phones and computers to trickle charge them in an everyday environment. At low enough costs, photovoltaic blankets could be used as covers for electric vehicles.