this post was submitted on 21 Dec 2023
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[โ€“] willis936@lemmy.world 8 points 10 months ago* (last edited 10 months ago) (1 children)

There is 1.4E21 kg of water on Earth. 0.03% of hydrogen is deuterium, a suitable fusion fuel. H2O has an atomic mass of 18 and O has an atomic mass of 16, so Earth has 4.7E16 kg of deuterium readily centrifuged out of ocean water.

D-D fusion converts about 0.1% of mass to energy (4 MeV / c^2 / 4 Daltons). E=mc^2. So we have 4.2E30 (420E28) Joules of fusion fuel ready for us on Earth. We used 2400 TWh of energy last year. If we used this amount indefinitely then we would have 485 billion years of fuel.

Bonus: deuterium depletion would have virtually no environmental effect.

[โ€“] luthis@lemmy.nz 2 points 10 months ago

This is the answer we all needed.