# Fuel cells

Cells that turn hydrogen or other fuels straight into electricity, with heat as a by-product.

Source page: https://www.materialinsights.org/energy/e_fuel_cells/

Conversion and use · Conversion devices · No. 102

- Conversion and use
 Conversion and use · Conversion devices · Foundation · Energy

A fuel cell makes electricity from hydrogen with no flame at all, and its only exhaust is water.

Chart: Illustration: Fuel cells

##### Where it comes from

Chart: Map of where it comes from

Hydrogen meets oxygen across a membrane or ceramic without burning, sending electrons round a circuit; a kilogram of hydrogen yields about 18.6 kWh at 56%.

##### Three things to know

1. At room temperature a hydrogen fuel cell can never exceed about 83% efficiency, because some energy must leave as heat (calculated).
2. Platinum catalyst ink and its application make up about 53% of a truck fuel cell stack's cost.
3. A truck system costs about USD 282 per kW at today's low volumes, against a modelled USD 155 at mass production.

##### The journey

1. 1 **Fuel**Hydrogen, natural gas or methanol
2. 2 **Anode**Catalyst splits fuel into protons, electrons
3. 3 **Membrane**Ions cross, electrons take the circuit
4. 4 **Cathode**Oxygen from air joins to make water
5. 5 **Output**DC power, heat, trucks or data centres

##### Go deeper pick a tab to open it in full

## Other sections

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