You need forms of storage for that. The conundrum can be turned on its head - "What do you do when you have nuclear and the businesses and factories are closed ?" You either simply waste nuclear capacity that you've paid and waited years for to be built - or you need forms of storage to make use of it. Both Nuclear and Renewables really want storage, they will compete for it.
If you can only make use of 60% of a nuclear plants capacity, you're price per unit is 100/60 more than the 'base-load' ideal that it was sold for. And another thing future nuclear plants will have to run alongside - is more and more renewable supply since renewables are cheaper and faster to build. We will have a situation where almost all demand is met by renewable supply eventually, and before that situation the demand left nuclear will decrease from 70,60,50,40,30...% - that's even without storage. How many decades do you expect it will take before those plants built with contracts to run for half a century or more, become pointlessly uneconomic ?
If there's too much power, it will be dirt cheap, and you'll charge your electric car then, which will maybe become affordable by then. Also with smart grid you'll regulate water heaters, ACs etc.
Still better to have too much power than not enough... Especially if eg. Russia decides to close the gas pipe, or if americans decide to "bring democracy" to another middle eastern state and that disrupta oil delivery.
We've sidetracked nuclear for decades now... The best time was decades ago, and the second vest time to build some new ones is now.
Electric cars are affordable now, assuming electricity is dirt cheap.
Nissan Leaf: $17K after tax incentives, $27K before.
Gas is $5/gallon. You can buy 5400/gallons for the price of an unsubsidized leaf.
Assume a leaf-alike ICE car gets 40 miles per gallon. It will go 216K miles for the unsubsidized retail price of the leaf.
Leaf batteries last at least 100K miles, and cost about $6K.
The purchase cost of the ICE car, and 216K miles of motor oil, engine and exhaust work have to be under $6K ($12K if the leaf batteries need to be swapped twice) or the leaf is cheaper.
No, having too much power without storage is exactly as bad as not enough. That's how the physics works. It's a zero sum game or it's lights out for the grid. It takes a lot of smart people and simulations to do a semi decent job of walking that tightrope day after day after day. Overproduction is a huge problem, as evidenced by the frequent negative power pricing of CA solar
If you have the infrastructure to produce hydrogen at scale you pretty much automatically have the infrastructure to store excess renewable production. That makes the "baseload!!" argument for nuclear moot.
It may be still better to run nuclear plants then. We'll need data from modern nuclear designs, (especially the small ones) but renewables are not exactly free to run. Storage degrades, solar degrades, lithium needs to be mined, turbines mean lots of mechanical parts, etc. We may learn that running just the renewables common today is even more uneconomic.
The maintenance burden you suggest for wind turbines is exaggerated. Compared to a gas car there are way fewer moving parts in common wind turbines, and some designs with no moving parts are being tested: https://www.windpowerengineering.com/dutch-wind-wheel-genera...
Additionally, battery degradation appears to be primarily related to high speed charging. In decade old battery packs that were not charged at extreme rates like 2C or above, you rarely see significant degredation. Grid scale operators will almost certainly manage their battery farms to limit the C rate to optimize battery life and long term profits.
Compared to a gas car a wind turbine is a completely different mechanism with a completely different scale, material requirements, elements exposure, and pretty much everything apart from "it has spinning things".
I can't exaggerate the maintenance burden for the turbines, because I didn't claim what it is, beyond that it exists. We'll have to compare it to new nuclear plants before stating which becomes uneconomical.
Solar degradation is commonly estimated at 20% in 25y, but then we get inverter failures on top of that which account for ~80% of issues in home installations. Batteries are commonly estimated to lose 20% capacity in 10y. All of those stack up too. Again - we'll have to compare the actual numbers which we don't have yet.
