Development and on-sun performance of dish-based HCPV

The paper describes a new system architecture optimized for utility-scale generation with concentrating photovoltaic cells (CPV). The system concept is optimized to use predominantly low-cost materials manufactured by methods proven for high volume production. Triple-junction cells are used to convert 1000x concentrated sunlight into electricity. Compared to silicon panels, these commercially available cells convert at least twice as much of the incident sunlight energy into electricity, and at 1000x optical concentration, they cost one-tenth as much per watt of power output. The architecture combines three novel elements: large (3.1mx3.1m square) paraboloidal glass dish reflectors to collect and concentrate the sunlight; compact receivers at each dish focus, each one incorporating multiple, actively cooled cells; and a lightweight steel spaceframe structure to hold multiple dish/receiver units in co-alignment and oriented to the sun. A manufacturing process for replicating the reflector dishes is well advanced in development at the Steward Observatory Mirror Lab. A lightweight steel spaceframe structure to hold and track eight dish/receiver units to generate 20 kW has been completed. Tests over several months showed that for 99% of the time the tracking error was less than 0.1 degree. A test receiver populated with 8 out of 36 cells and attached to the tracker was operated for two months, yielding consistently over 500 W for much of each day. The receiver also maintained 95% of full power for mispointing of 1/2°. The receiver is now being completed with its full 36 cell complement, for >2kW output. This technology is being commercialized by REhnu, LLC, under an exclusive license from the University of Arizona.