Electrolyzer Specific Energy Consumption Calculator

Combine measured power draw, runtime, hydrogen output, and auxiliary loads to benchmark electrolyzer specific energy consumption (SEC) in kWh per kilogram.

Aggregate DC and AC electrical input measured in kilowatts.
Total hours represented by the measurement window.
Mass of hydrogen delivered during the same window.
Leave blank to assume 0 kWh. Include compression, chilling, or water treatment energy when tracked separately.

Verify metering alignment across electrical feeds, hydrogen custody transfer, and auxiliary loads. SEC calculations are sensitive to inconsistent boundaries and measurement error.

Examples

  • 2,000 kW for 16 h producing 800 kg with no auxiliary energy ⇒ Specific energy consumption: 40.00 kWh/kg H₂ | Electrical efficiency vs LHV: 98.50 % | Total energy input: 32,000.00 kWh
  • 1,500 kW for 24 h producing 900 kg with 500 kWh auxiliary load ⇒ Specific energy consumption: 40.56 kWh/kg H₂ | Electrical efficiency vs LHV: 97.16 % | Total energy input: 36,500.00 kWh

FAQ

What measurement window should I use?

Use a period where power draw and hydrogen output are both metered—commonly one hour, one shift, or an entire day. Longer windows smooth transient behaviour and improve accuracy.

How do I treat heat recovery or oxygen credit?

This calculator focuses on electrical SEC. If you credit recovered heat or oxygen sales, document those adjustments separately so stakeholders understand the base electrical efficiency first.

Can I enter percentages or decimals for the inputs?

All inputs represent physical magnitudes—enter kilowatts, hours, kilowatt-hours, and kilograms directly. The calculator handles optional fields left blank by assuming zero auxiliary energy.

Why is efficiency flagged above the theoretical minimum?

Values under 39.4 kWh/kg imply more energy output than the hydrogen contains on an LHV basis. The tool highlights this so you can re-check metering boundaries, higher-heating-value references, or data entry errors.

Additional Information

  • SEC is expressed as kilowatt-hours per kilogram of hydrogen delivered.
  • The optional auxiliary energy input defaults to 0 kWh when left blank, ensuring the numerator reflects only stack power if balance-of-plant loads are unavailable.
  • The theoretical lower heating value (LHV) of hydrogen is approximately 39.4 kWh/kg; results close to this indicate high electrical efficiency.
  • Efficiency above 100% signals inconsistent measurements or inclusion of higher-heating-value references—reconcile boundaries before reporting.

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