Towards Climate Neutrality by 2050: Role of Aluminum for Short‐ and Long‐Term Energy and Hydrogen Storage

Reaching climate neutrality by 2050 requires innovative long-term energy storage (LTES) solutions beyond the current use of fossil fuels. While hydrogen is widely promoted, its low volumetric energy density, complex storage requirements, and limited infrastructure readiness raise questions about scalability. This Perspective paper argues that aluminum deserves attention as a strategic energy carrier. With an exceptionally high volumetric energy density, global availability, and full recyclability, aluminum offers unique advantages for seasonal storage and sector coupling. We highlight the promising high-temperature aluminum-steam oxidation pathway, which produces both heat and hydrogen alongside gamma-Al2O3, directly recyclable in decarbonized smelting processes. Beyond technical feasibility, we discuss system-level opportunities, from coupling aluminum-based storage with renewable-powered smelting plants to enabling multi-service energy hubs for electricity and mobility. Preliminary techno-economic assessments show that aluminum-based hybrid cycles can achieve round-trip efficiencies of 30-36% in power-to-power applications and competitive levelized costs for electricity and hydrogen production in the power-to-X framework. Moreover, key performance indexes show aluminum-based hydrogen aboveground storage can reach densities exceeding Clean Hydrogen targets by a factor of seven, with competitive CAPEX and OPEX values. These results highlight aluminum's potential to complement or outperform hydrogen in enabling reliable, high-density, and fully recyclable energy storage within decarbonized energy systems.