Demonstration of Infrared-Photovoltaics for a Full-Spectrum Solar Energy System

A nonimaging (NI) device and infrared-photovoltaic (IR-PV) array for use in a full-spectrum solar energy system has been designed, built, and tested (Dye et al., 2003, “Optical Design of an Infrared Non-Imaging Device for a Full-Spectrum Solar Energy System,” Proceedings of the ASME International Solar Energy Society Conference; Dye and Wood, 2003, Infrared Transmission Efficiency of Refractive and Reflective Non-Imaging Devices for a Full-Spectrum Solar Energy System,” Nonimaging Optics: Maximum Efficiency Light Transfer VII, Proc. SPIE, 5185; Fraas et al., 2001, Infrared Photovoltaics for Combined Solar Lighting and Electricity for Buildings,” Proceedings of 17th European Photovoltaic Solar Energy Conference}. This system was designed to utilize the otherwise wasted infrared (IR) energy that is separated from the visible portion of the solar spectrum before the visible light is harvested. The IR energy will be converted to electricity via a gallium antimonide (GaSb) IR-PV array. The experimental apparatus for the testing of the IR optics and IR-PV performance is described. Array performance data will be presented, along with a comparison between outdoor experimental tests and laboratory flash tests. An analysis of the flow of the infrared energy through the collection system will be presented, and recommendations will be made for improvements. The IR-PV array generated a maximum of $26.7W$⁠, demonstrating a conversion efficiency of the IR energy of 12%.