# Electrolysers: Overview

Machines that use electricity to split water, brine and alumina

Source page: https://www.materialinsights.org/energy/e_electrolysers/overview/

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)](https://www.mysteel.net/news/5111608-iai-global-primary-aluminum-output-exceeds-73-million-t-in-2025), 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 Hydrogen](https://www.materialinsights.org/chemicals/hydrogen/)[Ni Nickel](https://www.materialinsights.org/commodities/nickel/)[Pt Platinum](https://www.materialinsights.org/commodities/platinum/)[H₂O Water](https://www.materialinsights.org/commodities/water/)

#### Also in Conversion devices
[ST Steam turbines and thermal power plants](https://www.materialinsights.org/energy/e_steam_turbines/)[CCGT Gas turbines and combined cycle](https://www.materialinsights.org/energy/e_gas_turbines/)[ICE Internal combustion engines and gensets](https://www.materialinsights.org/energy/e_engines/)[Gen Generators and alternators](https://www.materialinsights.org/energy/e_generators/)[Mot Electric motors and drives](https://www.materialinsights.org/energy/e_motors/)[PE Transformers and power electronics](https://www.materialinsights.org/energy/e_power_electronics/)[FC Fuel cells](https://www.materialinsights.org/energy/e_fuel_cells/)[HP Heat pumps, air conditioning and refrigeration](https://www.materialinsights.org/energy/e_heat_pumps/)[EH Electric heating](https://www.materialinsights.org/energy/e_electric_heat/)[LED Lighting and displays](https://www.materialinsights.org/energy/e_lighting/)[Blr Boilers, furnaces and stoves](https://www.materialinsights.org/energy/e_combustion_heat/)

Explore paths from here
 More on this tile in the tabs above: science and limits, value chain, unit economics, engineering methods, equipment and suppliers.

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_electrolysers/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_electrolysers/correlation/index.md)
- [Science and limits](https://www.materialinsights.org/energy/e_electrolysers/science/index.md)
- [Value chain](https://www.materialinsights.org/energy/e_electrolysers/valuechain/index.md)
- [Unit economics](https://www.materialinsights.org/energy/e_electrolysers/economics/index.md)
- [Engineering methods](https://www.materialinsights.org/energy/e_electrolysers/methods/index.md)
- [Equipment and suppliers](https://www.materialinsights.org/energy/e_electrolysers/equipment/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_electrolysers/links/index.md)