In one line
Hydrogen electrolyser using a solid polymer electrolyte, offering fast response and high current density at higher capex than alkaline.
What it means
PEM (Proton Exchange Membrane) electrolysers use a solid polymer electrolyte to produce hydrogen from water. They tolerate variable input power well, making them a good fit for renewable-electrolyser coupling. 2026 PEM capex sits at $900–$1,400/kW (vs $600–$900 for alkaline) but PEM scales smaller, ramps faster, and operates at higher pressures — useful for distributed green hydrogen production.
Related terms
Browse every term in the renewable energy glossary, or read the latest analysis on Green hydrogen.