The transition toward a decarbonized energy system requires long‐term energy storage (LTES) solutions capable of complementing hydrogen‐based technologies. This study presents an exploratory life cycle assessment (LCA) of a primary aluminum–air battery (AAB) system as a prospective solid‐state LTES option, benchmarked against gaseous hydrogen (GH 2 ) with underground storage and liquid hydrogen (LH 2 ) with cryogenic tank. The AAB is evaluated under current and prospective aluminum production scenarios across different geographic contexts, and is benchmarked against alternatives using identical supply chain and use‐phase assumptions. AAB system achieves round‐trip efficiencies of 29–35%, exceeding GH 2 and LH 2 by at least 2% and 10%, respectively. Consequently, GH 2 outperforms AAB across all categories on a cradle‐to‐use basis only thanks to underground storage, while AAB showing competitive performance it performs better than LH 2 in global warming potential (GWP 100 ) impact category. The conducted uncertainty analysis reveals that AAB might outperform H 2 in GWP and eutrophication potential (freshwater) under favorable conditions. Overall, the findings highlight trade‐offs realizing climate benefits while mitigating resource and ecosystem impacts. Advancing low‐carbon smelting, material circularity, optimized logistics, and durable low‐impact components will be essential for enabling AAB to serve as a sustainable complement or partial substitute for hydrogen‐based LTES in future low‐carbon energy systems.
Ersoy et al. (2026) studied this question.