Comment by kergonath
5 days ago
> Even in that case, nuclear fission could not beat solar or eolic ROI.
Neither solar or wind are free. There are costs associated e.g. with building, shipping, maintaining, decommissioning these things (and hopefully at some point recycling, but that’s not solved). Looking at the whole picture, these costs are not that different. These technologies are complementary, they have very different characteristics.
> Current estimates put fussion at $120/MWh.
Current estimates are completely unreliable, because no industrial-scale demonstrator was built. They are a useful tool for planning and modeling, but not solid enough to build an industrial strategy on them. (And it’s “fusion”)
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).
I don't think current costs for fusion are useful for modeling, or really anything, because there's nothing there yet. We don't even have prototypes.
But if there is not a clear and speedy path to get fusion to $30/MWh it's not going to make it. Batteries, solar wind, and geothermal are all busy deploying and getting cheaper every month, year, and decade. The grid system possible with 2035's solar and battery tech is going to be completely unimaginable to today's grid ops.