Thermoradiative Solar Power Scavenging for Satellites

West Coast Solutions (WCS), the Georgia Institute of Technology (GT), and Teledyne Judson Technologies (TJT) have teamed to propose the second phase of the Integration of Thermoradiative (TR) Cells into Solar Panels for Satellite Power Scavenging program to meet the challenges as posed in Space Force Topic SF224-0014, Energy Harvesting. The WCS-GT-TJT technical approach centers on combining TR and photovoltaic (PV) power conversion into a “hybrid” system to scavenge waste heat from the PV process and thus yield higher power conversion efficiency than PV alone. During a successful Phase I, several potential TR materials including Indium Antimonide (InSb) and Mercury Cadmium Telluride (MCT or Hg1-xCdxTe) with various Cadmium mole fractions were studied. Calculations performed during Phase I indicate a near term potential for the hybrid PV+TR system to generate total power of 395.75 W/m2.  During Phase II, we propose the use of Indium Arsenide Antimonide (InAs1-xSbx). InAs1-xSbx is a material with which TJT has a substantial amount of experience, which limits the upfront development costs, which in turn  permits us to execute the complete Phase II proposed Technical Objectives (TOs) within the available budget. Initial modeling of InAs1-xSbx has been performed and it has been shown that with proper thermal management, InAs0.2Sb0.8 can generate 10.65 W/m2 at 350.7K with Antimonide (Sb) mole fraction of 0.8. This improves the system with PV cell by 2.77%, which is comparable to the projections for the more expensive MCT material. In Phase II, the TR and hybrid PV+TR math models will be matured, TR cells will be manufactured and tested, a hybrid proof of concept PV+TR array will be fabricated, and the hybrid array will be tested with a solar simulator as the power source and ultimately flown and tested in a high altitude balloon. As a primary objective in Year 1, testing will be performed on the fabricated TR cells to correlate the developed math model to the experimental data. In Year 2, TRL 5 proof of concept results will position the WCS-led Team to develop a path-to-flight, TRL 6 prototype hybrid PV-TR cell in a second Phase II or Phase III effort.