[jlevers]

Uranium can be extracted from seawater, and my understanding is that there's enough uranium in the oceans to last 10s (maybe 100s?) of thousands of years at current energy consumption levels. It's also renewable, albeit on a very long timescale -- but the timescales of consumption and renewal for uranium in seawater are much closer in length than the consumption/renewal timescales for fossil fuels.

[runarberg]

Wikipedia informed me that uranium concentration in seawater is estimated at 3.3 parts per billion (0.0033ppm)[1] while lithium concentration in seawater is estimated at 0.14 to 0.25 parts per million with pockets existing with concentration up to 7ppm[2].

Surely by the time we come up with the technology to harvest uranium from seawater, nuclear fission technology will be rendered obsolete as storing power from solar will be much much cheaper with lithium-ion batteries harvested from the same oceans, but with 100 times more efficiency.

1: https://en.wikipedia.org/wiki/Uranium_mining#Seawater_recove...

2: https://en.wikipedia.org/wiki/Lithium#Terrestrial