# Fusion fuels

Light atoms that release energy when joined: deuterium from seawater, lithium, helium-3.

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

Natural sources · Earth, gravity and atoms · No. 19

- Natural sources
- Origin: Nuclear
- Renewable: Effectively limitless if practical
 Natural sources · Earth, gravity and atoms · Foundation · Energy

Every cubic metre of seawater holds 33 grams of deuterium, fuel enough for millions of years if fusion ever works.

Chart: Illustration: Fusion fuels

##### Where it comes from

Chart: Map of where it comes from

Fusion joins very light nuclei, as the Sun does; the practical fuels are deuterium from seawater and tritium bred from lithium.

##### Three things to know

1. The world's tritium supply is only a few tens of kilograms, and it decays by about 5.5% a year.
2. Helium-3, a rarer fusion fuel, is mainly lunar: about 25 t per km2 of high-titanium Moon soil.
3. The US National Ignition Facility fired its record laser shot in December 2022, but no machine yet makes net electricity.

##### The journey

1. 1 **Seawater**Deuterium spread evenly through all water
2. 2 **Lithium**Bred into tritium inside the reactor
3. 3 **Fusion**Light nuclei forced together, as in the Sun
4. 4 **Reactor**No device yet delivers net electricity

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## Other sections

- [Overview](https://www.materialinsights.org/energy/e_fusion_fuels/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_fusion_fuels/correlation/index.md)
- [How energy resides](https://www.materialinsights.org/energy/e_fusion_fuels/resides/index.md)
- [Abundance](https://www.materialinsights.org/energy/e_fusion_fuels/abundance/index.md)
- [Fluctuation in time](https://www.materialinsights.org/energy/e_fusion_fuels/time/index.md)
- [Across the Earth](https://www.materialinsights.org/energy/e_fusion_fuels/geography/index.md)
- [Impact on nature](https://www.materialinsights.org/energy/e_fusion_fuels/nature/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_fusion_fuels/links/index.md)