Re:MIT-designed project achieves major advance toward fusion...
by ben_w on Thursday September 09, 2021 @04:52AM
(#28467678)
Per battery or overall to the planet?
Per unit of storage, Wikipedia says the lifetime storage capacity of batteries etc. relative to energy needed to construct them is:
Lead acid: 5 times construction energy; Vanadium redox: 10; LiIon: 32; Pumped hydro: 704; Compressed air: 792.
I can’t remember where I’ve seen this, but I think a unit of PV produces all the energy it took to manufacture after a month or two.
If you mean overall? As a rough guide we emit about 35GT CO2/year which is about 9.5e12 kg carbon; burning carbon releases about 32MJ/kg; so about 3e20 J/year, or 9 TW, or 19 mW/m^2.
There’s more energy in the hydrogen in gases and oils, this is just a ballpark estimate of the thermodynamic output of burning that much does to directly heat the planet.
Per unit of storage, Wikipedia says the lifetime storage capacity of batteries etc. relative to energy needed to construct them is:
Lead acid: 5 times construction energy; Vanadium redox: 10; LiIon: 32; Pumped hydro: 704; Compressed air: 792.
I can’t remember where I’ve seen this, but I think a unit of PV produces all the energy it took to manufacture after a month or two.
If you mean overall? As a rough guide we emit about 35GT CO2/year which is about 9.5e12 kg carbon; burning carbon releases about 32MJ/kg; so about 3e20 J/year, or 9 TW, or 19 mW/m^2.
There’s more energy in the hydrogen in gases and oils, this is just a ballpark estimate of the thermodynamic output of burning that much does to directly heat the planet.