Internal Heat Gains in a Lunar Base—A Contemporary Case Study

Abstract

The Moon’s environmental conditions present limited opportunities for waste heat dissipation, so internal heat gains (IHG) are a key component of thermal balance in a lunar building. Despite the significant development in energy saving and energy storage technologies of the last thirty years, the issue of IHG in lunar buildings has not been readdressed since the early 1990s. This study is based on an inspection of internal heat sources conducted aboard LUNARES, the first European extraterrestrial analogue habitat. The equipment absent on LUNARES, but indispensable for an actual lunar base, was identified and accounted for, along with additional laboratory and maintenance equipment. Three main groups of internal heat sources were identified and studied in detail. Waste heat generated by electric devices was accounted for, along with occupational heat loads adjusted for lunar partial gravity conditions. Assuming a photovoltaic power source for the studied building, two alternative energy storage systems (ESS) were analysed as another source of waste heat. Depending on the time of lunar day and applied ESS, the nominal IHG were between 73 and 133 W/m2. The most significant internal heat sources in a lunar base are life support systems and potentially, regenerative fuel cells; thus, lithium–ion batteries were recommended for ESS. Within assumed parameter range, parametric study exhibited differences in IHG between 41.5 and 163 W/m2.

Parametric Study of a Lunar Base Power Systems

“…These solutions are reliable and able to work continuously for years, regardless of environmental conditions. In particular, space-rated, compact nuclear reactors are not dependent on the availability of solar radiation and thus are able to continuously supply power to a lunar base without a need for a massive, highcapacity energy storage system (ESS) [27,[33][34][35][36]. Nonetheless, when using a nuclear reactor to power a manned lunar base, the issue of radiation protection must be addressed.…”

“…Colozza 2020 [27] calculated the constant power demand for an ISRU oxygen production facility and six-personnel lunar base camp to be 25.8 kW and 28.05 kW, respectively. Kaczmarzyk et al 2020 [33] calculated their lunar base daily mean power load to vary between 6.7 kW at temporarily unmanned, "keep alive" mode up to 13.1 kW while operating at the maximum assumed capacity. It is to be observed that the analyses presented above are all case studies, each conducted for a particular lunar base concept for a fixed location on the lunar surface.…”

“…It is to be observed that the analyses presented above are all case studies, each conducted for a particular lunar base concept for a fixed location on the lunar surface. Only [27] and [33] examined alternative power and energy storage systems for the studied bases, nonetheless still for single lunar locations and their resulting environmental conditions. More importantly, all of these works assume 100% relative sunshine duration which, in case of some interesting lunar locations, may be far remote from the fact.…”

“…We based some aspects of this analysis on the lunar base power load calculation procedure presented in the previous work of the corresponding authors-Kaczmarzyk et al 2020 [33]. This study was performed for a lunar base of the same architecture as of the LUNARES habitat, although the architecture of the base influenced only the power demand of a base TCS, which presents a relatively small portion of the total power load.…”

“…3. Whilst performing this study, it was found to be necessary to introduce some corrections to the original assumptions made by Kaczmarzyk et al 2020 [33]. They are as follows:…”