Electrolysis
The process of using electricity to split water (H2O) into hydrogen (H2) and oxygen (O2). The main electrolyzer types are PEM (proton exchange membrane), alkaline, and solid oxide (SOEC).
Why It Matters
Electrolysis is how green hydrogen is made. The efficiency and cost of electrolyzers are key factors determining whether green hydrogen can compete with fossil-fuel-derived hydrogen.
Related Topics
Related Terms
Green Hydrogen
Hydrogen produced by splitting water (electrolysis) using renewable electricity. The process produces zero direct greenhouse gas emissions. Currently costs $4-$8/kg vs. $1-$2/kg for conventional (gray) hydrogen.
Fuel Cell
An electrochemical device that converts hydrogen and oxygen directly into electricity, water, and heat — the reverse of electrolysis. Fuel cells are 40-60% electrically efficient with no combustion emissions.