Hybrid Energy Storage and Hydrogen Supply Based on Aluminum—a Multiservice Case for Electric Mobility and Energy Storage Services

Abstract

The realization of a fully decarbonized mobility and energy system requires the availability of carbon‐free electricity and fuels which can be ensured only by cost‐efficient and sustainable energy storage technologies. In line with this demand, a techno‐economic evaluation of aluminum as a cross‐sectoral renewable energy carrier is conducted. The assessment, based on a newly developed process, involves the wet combustion of Aluminum at 700 °C resulting in heat and hydrogen (H2) generation. The designed conversion plant enables the contemporaneous generation of electricity and on demand H2 (up to 4 MW and 46.8 kg h–1) with round‐trip efficiencies as high as 40.7% and full recycling of the Al2O3 waste. This study, assuming the carbon‐free production of Al and three different energy cost scenarios, proves the feasibility of the e‐fueling station business case. The overall energy conversion including fuel production (power‐to‐Al), utilization (Al‐to‐power and Al‐to‐H2), and recycling requires a capital investment of 5200 € per kW installed power without additional primary material demand. Hence, the estimated power‐to‐X cost for the Al‐based H2 is estimated in the range of 4.2–9.6 € kg–1 H2, while wind and solar power based green H2 production cost varies from 6.5 to 12.1 € kg–1 H2.