Alkaline Electrolysis for Hydrogen Production at Sea: Perspectives on Economic Performance

Alkaline electrolysis is already a proven technology on land, with a high maturity level and good economic performance. However, at sea, little is known about its economic performance toward hydrogen production. Alkaline electrolysis units operate with purified water to split its molecules into hydrogen and oxygen. Purified water, and especially that sourced from the sea, has a variable cost that ultimately depends on its quality. However, the impurities present in that purified water have a deleterious effect on the electrolyte of alkaline electrolysis units that cause them to drop their energy efficiency. This, in turn, implies a source of economic losses resulting from the cost of electricity. In addition, at sea, there are various options regarding the electrolyte management, of which the cost depends on various factors. All these factors ultimately impact on the levelized cost of the produced hydrogen. This article aims to shed some light on the economic performance of alkaline electrolysis units operating under sea conditions, highlighting the knowledge gaps in the literature and initiating a debate in the field.