npub1vypq6jrs2melhg7y3ug2jn6dguqs6kzxhmtcd3a3qezelautzyvquxaghx (npub1vyp…aghx) npub1dl8xsc6wae6d2pejmkfsz9h2ysvrq0x3mq6j56en02p4x7j7u27s5j4tsq (npub1dl8…4tsq) ok let's consider seawater.
Current demand is 60kt of uranium per year. Assuming we increase our demand by 100x (to replace electric and non-electric uses of fossil fuels), but offset that by increasing our efficiency by 60x u(sing breeders), that leads to about 120kt per year.
Seawater is 3 parts per billion uranium, so 120kt uranium corresponds to 40 trillion tons of seawater. Since seaweater is about 1 ton per cubic meter, that's 40 trillion cubic meters.
The surface of the ocean is 360 trillion square meters. So our annual demand for uranium would consume the top meter of water from 11% of the ENTIRE OCEAN.
Let's be wildly optimistic and pretend that we could build this out for 0.1% of the ocean surface. Annually we would be using the top 100 vertical meters of water. Lifting that water to sealevel would require 500kJ per ton, for a total energy budget of 20 million terajoules per year. Add in other costs (materials, repairs, inefficiency) and we can probably round that up to 50 million terajoules. That would be about 10% of our current annual global energy usage. That's a 1:10 return on energy invested.
It gets more expensive if the economy grows. If demand doubles, we have to get water from twice as far down, which yields a 1:5 return on energy invested.
If demand rises by 10x (which is a conservative estimate for 100 years of growth at the current rate), we would end up spending more on extraction than we get out of the process.
Obviously at some point we would expand horizontally instead of vertically, but paving the ocean starts facing other problems -- such as killing the phytoplankton that produce half the world's oxygen.
Kim /
npub19j…r2lmd
2023-07-13 12:38:38
in reply to nevent1q…5l52
Author Public Key
npub19j9jvf72vx48za2ug978yu3f7gp7re2y20famqej28thjpjxpyrser2lmdPublished at
2023-07-13 12:38:38Event JSON
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