PV SPACE POWER GENERATION USING HOLOGRAPHIC WAVELENGTH SEPARATING CONCENTRATORS

POC PURPOSES AN ADVANCED SOLAR POWER SYSTEM FOR SMALL SPACECRAFT THAT EMPLOYS A NEW TYPE OF HOLOGRAPHIC CONCENTRATOR TO SELECTIVELY CONCENTRATE DIFFERENT WAVELENGHTS OF SOLAR ENERGY ONTO DIFFERENT PHOTOVOLTAIC RECEIVERS. THE NOVELTY OF POC'S APPROACH INCLUDES THE USE OF ITS UNIQUE HOLOGRAPHIC TECHNOLOGY WHICH ALLOWS THE PRODUCTION OF VERY HIGHLY EFFICIENT LIGHT COLLECTORS IN THE ENTIRE VISIBLE AND NEAR IR SPECTRAL RANGE. SPECIFICALLY, POC'S IR HOLOGRAMS REPRESENT THE STATE-OF-THE-ART IN HOLOGRAPHY AND HAVE NOT BEEN MATCHED EVEN IN THE RESEARCH COMMUNITY. FURTHERMORE, THE NEW TYPE OF HOLOGRAMS ARE STABLE AT HIGH (200 DEGREE C) AND LOW (-180 DEGREE C) TEMERATURES AS WELL AS UNDER HUMIDITY AND VACUUM CONDITIONS GENERALLY EXPERIENCED IN THE SPACE APPLICATIONS. THIS SYSTEM INVOLVING POC'S VISIBLE AND IR HOLOGRAMS ADDRESSES THE PROBLEMS OF LOW SOLAR CONVERSION EFFICIENCY AND HIGH CONCENTRATOR WEIGHT THROUGH THE USE OF DIFFERENT PHOTOVOLTAIC RECEIVER MATERIALS. BECAUSE OF THE SEPARATE PHOTOVOLTAIC CELLS, EACH WITH A DIFFERENT BAND-GAP ENERGY, RECEIVING ONLY THOSE SOLAR PHOTONS WITH ENOUGH ENERGY TO PRODUCE ELECTRON-HOLE PAIRS, THE EFFICIENCY OF CONVERSION IS HIGH. THE HOLOGRAPHIC OPTICAL ELEMENTS USED IN THIS SYTEM ARE INHERENTLY LIGHTWEIGHT AND FLAT, MAKING DEPLOYMENT SIMPLE. OVERALL, THIS RECEIEVER IS MORE EFFICIENT IN POWER, SIZE AND WEIGHT THAN EXISTING SYSTEMS. ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS - THE SYSTEM IS A SIGNIFICANT IMPROVEMENT OVER THE USE OF CONVENTIONAL PHOTOVOLTAIC RECEIVERS IN SPACE POWER SYSTEMS. EFFICIENCY WILL BE BETTER THAN THAT OBTAINED FROM A TENFOLD CONCENTRATION OF SOLAR RADIATION. ADDITIONALLY, CELL LIFE WILL BE EXTENDED BECAUSE PROTONS THAT ONLY CONTRIBUTE TO HEAT (AND NOT TO USEABLE ENERGY) WILL BE REJECTED BY DIFFRACTION. KEY WORDS - HOLOGRAPHIC, HOLOCONCENTRATOR, ENERGY, PHOTOVOLTAIC, SOLAR, WAVELENGTH SEPARATION