Work out electrolyser sizing instantly with clear inputs, formula shown and shareable results.
Electrolyser rating is daily hydrogen demand times specific energy consumption, divided by the hours it will run, plus a design margin for degradation and turndown. Fewer operating hours means a larger and more expensive stack, which is why matching electrolyser hours to cheap electricity availability is the central design trade-off.
Electrolyser sizing
Power (kW) = hydrogen demand (kg/day) x specific consumption (kWh/kg) / operating hours, x (1 + margin)
Capital cost scales with rated power. Halving operating hours doubles the stack size needed, so the capital cost per kilogram roughly doubles even though electricity may be cheaper.
10-20% for stack degradation over life, which raises specific consumption by around 0.5-1% a year, plus any need to exceed nominal demand during peak periods.