Limits RegistryPUBLIC RECORD
Limits RegistryBloom Energy's solid oxide electrolyzer was independently measured by Idaho National Laboratory (a U.S. Department of Energy national lab) at 37.7 kWh/kg H2 (88.5% LHV-referenced efficiency) after roughly 500 hours of full-load operation, reported in 2022. The theoretical thermodynamic minimum is 33.3 kWh/kg on an LHV basis (39.4 kWh/kg on an HHV basis) — vendors routinely cite whichever basis flatters their number, so any comparison across electrolyzer efficiency claims needs to check which reference basis is being used.
The question, scope, and sources behind this Registry record.
Bloom Energy's solid oxide electrolyzer was independently measured by Idaho National Laboratory (a U.S. Department of Energy national lab) at 37.7 kWh/kg H2 (88.5% LHV-referenced efficiency) after roughly 500 hours of full-load operation, reported in 2022. The theoretical thermodynamic minimum is 33.3 kWh/kg on an LHV basis (39.4 kWh/kg on an HHV basis) — vendors routinely cite whichever basis flatters their number, so any comparison across electrolyzer efficiency claims needs to check which reference basis is being used.
The lowest specific electricity consumption (kWh of DC input electricity per kg of hydrogen produced, LHV-referenced) independently measured for an electrolyzer under sustained full-load operation.
Change a parameter to stress-test whether a proposed result is still inside the published specification. This is an audit aid, not a proof checker.
This record has no editable parameters. Read the formal question and assumptions before challenging it.
Current frontiers derived from accepted Claims.
An observed or demonstrated result; no opposing bound is implied.
The frontier is not sacred
Most progress starts with a disagreement that survives contact with evidence. If you can push the known lower bound up or pull the upper bound down, show us the work.
≥ when you have shown that at least this value is achievable.≤ when you have shown that anything above this value is impossible.No vibes. State the value, define the scope, and link the paper, proof, code, or reproduction that lets another person check it. Editors review every challenge before the public record changes.
Challenge this recordAssertions tied to evidence, attribution, and review.
The frontier as it changed over time.
Only accepted Claims matching the current specification contribute to the displayed bounds. Strict inequalities remain open; contradictory Claims require editorial review.
Permanent ID limitsregistry.com/limits/LR-HYDROGEN-PRODUCTION-EFFICIENCY
No active verified bounties are linked to this Limit.
View verified bounty tracker ↗No accepted machine-checked reproductions are recorded for this Limit.
Limits Registry. LR-HYDROGEN-PRODUCTION-EFFICIENCY. Hydrogen electrolysis efficiency. 2026.