hydrogen
Alkaline electrolyser
Also known as: ALK electrolyser
Mature hydrogen electrolyser technology using a liquid alkaline electrolyte (typically KOH), lowest capex per kW.
Alkaline electrolysers are the oldest commercial hydrogen production technology, using a potassium hydroxide (KOH) liquid electrolyte. They dominate 2026 global electrolyser capacity (~70% market share) with the lowest capex of any green-hydrogen technology ($600–$900/kW). Trade-offs: slower ramp than PEM, lower current density, larger footprint per kW. Best fit for steady-state operation at utility-scale green hydrogen projects.
Related terms
- PEM electrolyser — Hydrogen electrolyser using a solid polymer electrolyte, offering fast response …
- Green hydrogen — Hydrogen produced by electrolysis using renewable electricity, with near-zero li…