In-situ approach for thermal energy storage and thermoelectricity generation on the Moon: modelling and simulation

Abstract

Human, tele-operated rovers, and surface infrastructures are now being actively considered for lunar polarexploration. Current approaches to energy provision consider, among others, hybrid direct energy/chemicaltechnologies, such as solar photovoltaic arrays, batteries, and regenerative fuel cells. Due to the long period ofdarkness on the Moon and the challenges this poses to the aforementioned conventional energy generation andstorage technologies, there is a need to assess the potential of In-Situ Resources Utilization (ISRU) methods toenable or supplement long duration missions. We present a computational model (MATLAB) of a Thermal EnergyStorage (TES) system coupled to drive a heat engine (Thermoelectric Generator) to produce electricity. The TESmedium designed is based off processed lunar regolith, an abundant material present on the surface of the Moon.The architecture has been optimized to provide a minimum electrical power of 36 W per unit after 66 h of polarnight, but the modular nature of the model allows other ranges of parameter to be simulated. A trade-off betweenthis ISRU-based concept and conventional approaches for energy production and storage was performed andranked TES and thermoelectricity generation as the least appropriate option. This result is valuable in a period ofenthusiasm towards ISRU. It shows that processes exploiting extraterrestrial materials instead of Earth suppliesare not systematically attractive. Despite the non-favorable performances for the proposed concept, some per-spectives for the TES system are given as well as potential model improvements such as the need to assess the useof a Stirling heat engine.