Toward modeling principles for space energy system optimization

With the aim of establishing modeling principles for space energy system optimization, this paper systematically reviews existing energy system modeling studies and assesses their transferability to extraterrestrial environments. Core concepts from terrestrial energy system modeling, including technology selection, capacity expansion, sector coupling, and storage optimization, provide a valuable foundation. However, space applications require adaptations to account for material and commodity flows, thermodynamic constraints, demand structures and mission criticality, and substantial uncertainty in technology performance, resource availability, and environmental conditions. These challenges highlight the need for stronger coupling between technology-level thermodynamic analyses and system-level optimization, explicit representation of mission-critical demands, and stochastic and other uncertainty-aware optimization approaches. Based on these findings, preliminary modeling principles and key directions for future methodological development are identified. To demonstrate their applicability, a lunar space village case study is developed for a sustained settlement over a one-year operational period. The optimized system combines nuclear power, solar photovoltaics, batteries, electrolyzers, and fuel cells, resulting in a levelized cost of electricity of approximately 7,800 EUR /MWh. This provides a first quantitative benchmark for future lunar energy infrastructures. Overall, the study provides a methodological foundation for space energy system optimization and supports the development of scientific knowledge and modeling capabilities for the expanding commercial, industrial, and energy-related activities in space.