Electrical Power from Thermal Energy Scavenging in High Temperature Environments

Physical Sciences Inc. and Purdue University propose to develop a novel approach to scavenging heat from high intensity thermal environments encountered during space missions and converting this thermal power to electrical power at high efficiency. Examples include extremely hot heat shields during vehicle entry into planetary atmospheres (Mars/Venus probes) and during high speed ascent through planetary atmospheres (Sample return from Mars/Venus), hot claddings of radioisotope thermoelectric generators used for powering outer planetary spacecraft and multi-decade planetary bases (Mars/Venus/Lunar), as well as combustors and nozzles of space and launch propulsion systems. In this STTR we will develop an integrated metal hydride system and spectrally-tuned thermophotovoltaic power converter system that can extract heat during periods of high thermal intensity (tens of seconds), and convert it to electricity at greater than 25 percent efficiency. Following the end of this period, the system can continue to generate useful power for additional tens of minutes. In Phase I, for the power converter system, we will demonstrate feasibility of fabricating a critical component in larger areas (5 cm x 5 cm), and for the metal hydride (MH) system, we will experimentally characterize the MH decomposition/recombination reactions that enable continual electrical power generation for a useful duration after the period of high thermal intensity has ended. In Phase II, we will produce an engineering prototype of the integrated heat scavenging electrical power generator system, fully tested in laboratory environment and in simulated operational thermal environment, together with an analytical model of a functional system.