this post was submitted on 23 Aug 2023
174 points (90.3% liked)
Green Energy
2223 readers
96 users here now
Everything about energy production and storage.
Related communities:
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Why would an all nuclear grid need more than a day of storage? You just need to match constant supply with a 24 hour demand curve.
(And I doubt anyone's arguing for an all-nuclear grid, since renewables are so cheap when they're available. We just need enough dispatchable power on the grid to survive weather events without burning gas.)
Technically they need 200,000 years worth of storage. Although in that case it's more archival.
And you can't just balance load with nuclear reactors, they take forever (as in days to weeks) to spool up, you can't just switch them on. So you're still going to need some storage capacity and if you're going to have storage anyway you might as well have a simpler energy generation system to boot without all of the big complicated nuclear reactor equipment.
Plus of course the fact that you can stand up solar panels and wind turbines almost anywhere in 6 months, but you'll be wrangling for 30 years to build a new nuclear reactor.
Because they have weeks or months long unplanned outages every year, often correlated and are over-concentrated geographically so fail-over requires huge transmission overprovision.
As to that last, building a $20/W generator and keeping it in hot shutdown to use for 200 hours a year costs thousands of dollars per MWh. There are vastly cheaper ways to get 100 hour storage.
Has anyone actually built 100 hour storage at a significant scale? There's potential for things like iron-air and green hydrogen, but they seem like uncertain emerging technologies.
Pumped hydro exists in many places (and is available pretty much everywhere). There are also demo installs for other low-discharge batteries. Also "put another battery next to the other battery" isn't some undiscovered technology, as soon as it's necessary LFP is ready even if you assume there's no other option.
It doesn't really matter though because wind/solar has demonstrably higher grid penetration capability with less storage and less overprovision than nuclear. Geographic over-concentration and unreliability is a much bigger downside than intermittency in that regard.
So for grid reliability, it would be better to build (e.g.) a distributed fleet of 100 MW reactors than a single 1 GW reactor?
Yeah that would likely improve it, but then you're paying as much for the fuel as the renewable grid's total cost and much more on top of that for security and O&M. You also need to quadruple uranium mining overnight to just do the first fuel load for enough new generation to keep up with new wind and solar installs.
Rather than going to more and more tortured extents to try and make nuclear work, we could just do the thing that's working extremely well. In the absolute worst case where we assume medium and long term storage is impossible rather than not yet necessary, the total emissions from the residual thermal generation over tue next century are less than the emissions from delaying the transition to try and make nuclear work.