Holographic Light-Emitting Diode-Based Solar Simulator

NIST is seeking a large-area solar simulator to overcome the shortcomings of current devices. Therefore, Physical Optics Corporation (POC) developed in Phase I a new Holographic Light-Emitting-Diode (LED)-Based Solar Simulator (HOLIOS) system based on: high-power LEDs with electronic drivers; holographic filters; and collimating, homogenizing, and projection optics for indoor testing of photovoltaic (PV) modules. The combination produces an irradiation spectrum precisely matched to the solar irradiation spectrum, with a uniformity or +/-2% over the entire area. In Phase I POC delivered to NIST a proof-of-concept prototype with an array of high-power LEDs and one-of-a-kind LED driver electronics to produce irradiance approaching 50% of solar in the visible spectrum, covering a 0.3 m x 0.3 m area. In Phase II POC will produce a scaled-up multiple-module prototype simulating both solar irradiance under a wide range of air mass conditions, and atmospheric absorption by water, oxygen, ozone, and carbon dioxide molecules. It will irradiate a 0.6 m x 0.6 m to 1.5 m x 1.5 m area, depending on the number of modules, at irradiance levels that can be varied from <500 to 1100 W/sq.m, while maintaining uniformity of irradiance within +/-2% over the irradiated area.