Fusion fuels
Light atoms that release energy when joined: deuterium from seawater, lithium, helium-3.
Natural sources · Earth, gravity and atoms · No. 19
- Natural sources
- Origin: Nuclear
- Renewable: Effectively limitless if practical
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
- The world's tritium supply is only a few tens of kilograms, and it decays by about 5.5% a year.
- Helium-3, a rarer fusion fuel, is mainly lunar: about 25 t per km2 of high-titanium Moon soil.
- The US National Ignition Facility fired its record laser shot in December 2022, but no machine yet makes net electricity.
The journey
- 1 SeawaterDeuterium spread evenly through all water
- 2 LithiumBred into tritium inside the reactor
- 3 FusionLight nuclei forced together, as in the Sun
- 4 ReactorNo device yet delivers net electricity