SMARTS Modeling of Solar Spectra at Stratospheric Altitude and Influence on Performance of Selected III-V Solar Cells

Solar-powered fixed-wing high-altitude longendurance pseudosatellites (HALE or HAPS) are being developed to provide telecommunication and related services to markets across the globe. For technical, operational and regulatory reasons, these aircraft need to operate continuously at stratospheric altitudes, which is a challenge given the limited electrical energy available aloft. We have conducted SMARTS simulations to generate solar spectra at 20 km altitude on the Tropic of Cancer during the winter and summer solstices. Estimates of component cell currents for single junction and triple junction III-V cells were also calculated. These results and approach are expected to be of benefit to the calculation and optimization of performance of HALE aircraft.