Energy Storage for Lunar Surface Exploration

Abstract

This paper presents the updated results of a previous NASA study funded under the Advanced Exploration Systems (AES) Modular Power Systems (AMPS) project. This work focuses on generating high-level system sizing relationships for two lunar surface locations that serve as bounding conditions for most other locations. Four critical parameters are considered to provide sizing data: specific energy, energy density, specific power, and power density. Given the energy storage requirements or customer power demand for a lunar mission location, the data presented in this paper provides a method to determine the critical parameter values of a Regenerative Fuel Cell (RFC) system in order to perform high-level mission architecture trades.

Space Microgrids for Future Manned Lunar Bases: A Review

“…They can supply hundreds of watts of power for long extended periods of operation [59]. There are several types of FCs, out of which proton exchange membrane (PEM), solid oxide (SO), and regenerative fuel cells (RFCs) are advantageous for lunar base applications [59], [67], [68]. A PEM-FC consists of a polymeric proton-conducting membrane with a reaction-specific catalyzed hydrogen and oxygen electrode on each side of the cell [59], [68].…”

“…During the process, water vapour is produced as a byproduct that is continuously removed as it negatively impacts the overall reaction [68]. A RFC integrates a FC, an electrolyzer, and a multi-fluid reactant storage system [58], [59], [67], [69], thereby making FCs a rechargeable ESS to serve long-duration lunar surface missions. RFCs generally have separate electrolyzer and FC stacks but recently unitized RFCs have being developed to merge the FC and electrolyzer [59].…”

“…In general, electrochemical pressurization is more efficient than mechanical pressurization systems [68]. Therefore, considering the advantages and efficiency, PEM-RFCs seem very promising for space surface missions [59], [67], [68].…”

“…In general, for long discharge duration, RFCs are shown to have an advantage over the rechargeable batteries in terms of mass and specific energy [9], [58], [67], [68]. In [9], two EPSs including solar PVs assisted by batteries and RFCs are analyzed.…”

“…With longer operation, the mass of other components does not increase and only the reactants and storage tanks need to support the ESS requirements. Moreover, RFCs have separate energy conversion (FC and electrolyzer) and energy storage units (reactants storage tanks), permitting independent sizing of both [67], [68]. While in batteries, both energy conversion and storage are packaged in one unit [67].…”