In this paper, a seasonal energy storage based on the aluminium redox cycle (Al3+→Al→Al3+) is proposed. For charging, electricity from solar or other renewable sources is used to convert aluminium oxide or aluminium hydroxide to elementary aluminium (Al3+→Al). In the discharging process, aluminium is oxidized (Al→Al3+), releasing hydrogen, heat, and aluminium hydroxide or aluminium oxide as a by-product.

SPF Institute for Solar Technology