Comment by otherme123
5 days ago
Did anybody say they are free? But the costs of running solar or eolic are way lower than the costs of running fission, or the costs that likely would be running a fusion central. In case you don't know what ROI means, it is return on investment (i.e. building, shipping, mantaining decomission...).
As of today, we are closer to mass batteries as renewable companion than fusion, at least in terms of ROI. If both end up competing for lithium, it would go to batteries unless fusion becomes dirty cheap.
Current estimations are useful because they mark the starting point for fusion: they are at around 120. They need to reach 80 to replace fission. They need to reach 60 to replace batteries. Assuming batteries don't get better ROI.
Same numbers were useful 30 years ago for solar: it was fully functional, but not yet economically sound. It was not much than a toy and a promise (as it is fusion today). Only when prices made sense it turned to a serious energy source.
About lithium: DT fusion needs mostly Li-6. If it were separated, batteries would work just fine with Li-7.
I recall a story of some lab that was trying to make a lithium-based neutron detector. It wouldn't work, and when they investigated they discovered the lithium they had bought was almost pure Li-7. It was surplus sold back into the chemicals market from the US hydrogen bomb program (which needed Li-6).