Infrared Transmissive Concentrated Photovoltaics for Coupling Solar Electric Energy Conversion to Solar Thermal Energy Utilization

As solar power has garnered much attention as a renewable energy source, there is a need for a high-efficiency solar power system that supplies electricity at a competitive cost and that provides for the on-demand supply of electricity as well as energy storage. Monolithically integrated III-V semiconductors, for instance, have resulted in efficiencies greater than 40% in concentrated sunlight, but the cost of fabrication remains high. Additionally, current storage of electricity from solar power has been limited by available battery technology and by the ability of home-scale solar power generators to connect to the grid. By combining aspects of concentrating solar power (CSP)and concentrator photovoltaics (CPV), the transmissive CPV device, consisting of a multifunction PV cell mounted on a transparent base, enables the conversion of sunlight to electricity at very high efficiencies and that enables the transmission of solar thermal energy to heat storage devices for later use. High energy light is absorbed by the multijunction PV cell and converted directly to electricity, while low energy light is transmitted through the device to a thermal storage device, which may then be coupled to a heat engine to generate dispatchable electricity. The stored thermal energy can be used to generate dispatchable electricity or for other purposes where heat is required, such as industrial process, desalinization, home water heating, etc.