The potential role of reactive metals for a clean energy transition

Reactive metal-based storage systems are a new alternative to support the clean energy transition. Herein, the cases of Al and Na are presented, both preliminarily fulfilling the constraints regarding sustainability, but employing two rather different processes. Both, the steam combustion of molten Al for H-2 and heat production, and a new rechargeable battery, which makes use of seawater and sodium as electrodes, show promising round-trip efficiencies. The latter technology also allows CO2-trapping, desalination, Na metal, and chlorine production. It is argued that further research efforts are needed to verify the sustainability and ability of reactive metal-based technologies to compete with other storage technologies.