Replacing it all on a 20 year cadence seems like a reasonable assumption.
Arguments assuming a positive return to scale 4 orders of magnitude out may be true— or may be unduly optimistic. I don’t like to have too much faith extending the lines too far off the right of the graph. When that is required, I want whatever margin and ways to reduce risk as possible: which is why I would like more nuclear in the mix. A grid with 12pc nuclear and the rest renewable (so about 3-4pc of nameplate power nuclear) would require much less over provisioning and storage.
Replacing the whole system every 20 years still seems really wild to me, especially in worlds where price doesn't fall past the cost of maintenance, because the only wear part is the battery, and batteries are modular. We could, sure, I just showed the cost is a fraction of today's energy spend, it just seems really weird not to do something smarter instead.
It may be pessimistic. At the same time, you amortize things based on history.
Things like substations are amortized over 30-40 years. Battery banks don't have the history; a 20 year timeframe seems like a reasonable amortization time. Indeed, if technology improves and costs reduce like people are advocating for here, it'll be thrown away and replaced. If it wears out in ways that don't justify refurbishment, same. And refurbishment/recycling/etc are not well understood processes at scale, yet, nor are future usage patterns well enough understood to know if we will have those resources at the right places.
Again, we could get lucky: batteries could last longer than expected; we could use technologies that are close enough cousins and have a really good time at refurbishment; we could not hit any kind of scaling limitations with battery storage; etc. I agree battery storage is great. And I agree it could be sufficient alone (well, combined with other storage options) if we hit the top third of possible scenarios.
I just am concerned about the other scenarios. I can't rule them out. And if we're going to have insurance against them, it's time to buy it now.
I'd much rather face a future where people say that we wasted a few tens of billions on nuclear power plants than to face a future where people shake their head that we wasted the opportunity to save the climate by foregoing nuclear.
Isn't that the whole debate? What are we arguing about at this point?
I'm sorry, I don't think that cost is readily affordable!
> You agree that there's a reasonable chance the price could go down
I think the most likely outcome is that the price goes down. But I also think it's possible that the price goes up (decreasing returns to scale) as you try to build more.
> agree that parts other than the battery chemistry do indeed last much longer.
We often depreciate substations at 40 years despite parts inside lasting longer, and we have a whole lot of experience to value that. We don't have a lot of experience with long term lifecycle of batteries. E.g. recycling and decommissioning of batteries at scale is still a big unknown.
Idk, it seems like even pretty pessimistic arguments with frozen costs and early retirements suggest this is cheaper than the numbers you gave.
> That is assuming we can hit that scale in the next couple decades and that nothing happens to push up costs with increased scale.
This strikes me as odd to posit about a technology that has had a steady 23% cost reduction per doubling over the last 6 decimal orders of magnitude.