Electrolysers: Overview
Machines that use electricity to split water, brine and alumina
What this tile covers Equipment that uses electricity to split compounds: water into hydrogen, brine into chlorine, alumina into aluminium. Share of use 1% share of final energy use (2025)Share of world total final energy consumption (about 435 EJ, calculated: motor systems 13,462 TWh are 53% of electricity, so about 25,400 TWh or 91 EJ, and electricity is about 21% of final energy) that passes through this device or is used by this sector, latest year available. Electricity-based devices use electricity's 21% share of final energy (IEA WEO 2025). Overlaps between devices and sectors are allowed and noted. Aluminium smelting about 1,050 TWh (73 Mt in 2025 at a world average of about 14.4 MWh/t), chlor-alkali over 150 TWh, water electrolysis about 14 TWh (just over 4 GW at an assumed 40% load); about 1,215 TWh or 4.4 EJ, about 1.0% of roughly 435 EJ final energy (calculated). Overlaps heavy industry. Source: IAI: global primary aluminum output exceeds 73 million t in 2025 (reporting International Aluminium Institute data), Mysteel.
Key facts
| Chain | Electrical → chemical (H2) |
Included from the reference tables
- Water electrolysis (green hydrogen)
- Chlor-alkali
- Aluminium smelting
- Electroplating
Linked to the material world
H2 HydrogenNi NickelPt PlatinumH₂O WaterAlso in Conversion devices
ST Steam turbines and thermal power plantsCCGT Gas turbines and combined cycleICE Internal combustion engines and gensetsGen Generators and alternatorsMot Electric motors and drivesPE Transformers and power electronicsFC Fuel cellsHP Heat pumps, air conditioning and refrigerationEH Electric heatingLED Lighting and displaysBlr Boilers, furnaces and stovesExplore paths from here
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