No, intermittent sources need an affordably dispatchable source to produce when they can't. A steady, fixed cost source like nuclear, that must be producing most of the time to minimize the cost of its output, is unsuitable for acting as a backup to intermittent sources.
That's assuming you're using the steady source to cover for the intermittent source when it isn't generating. If you're using the steady source to replace the intermittent source entirely (as France had been doing) then it is producing most of the time and you don't have that problem.
This is probably the largest impediment to a 100% renewable grid. You might be able to get over the solar day-night thing with batteries if you had to because you can justify a lot of batteries if they're getting used every night, but the thing where sometimes it's cloudy for a straight month is a serious issue.
Right, it's an either-or situation. And now, with renewables crashed in cost and continuing to fall, it look's like renewables are winning.
You bring up batteries, but they would not be used for long term load leveling. The optimal solution is some combination of overcapacity w. curtailment, batteries for short term leveling, and hydrogen for long term leveling. Simple cycle turbine power plants can have a construction cost maybe ~5% of the cost/kW of a nuclear power plant (CC, around 10%), so building them and letting them sit idle most of the time is not a big deal.
Not exactly, they're still complementary, just not in that specific way.
Suppose you have 100% solar generation with enough batteries to survive the night, and then it's cloudy for a month and they generate half as much power. You can suppress demand some by raising prices, but suppressing it by 50% is unreasonable. Suppose you can suppress demand by 20%. Well then you still need enough long-term storage to cover 30% of your total demand for a month, which is really expensive for something you only use once every two years.
Now suppose you have 50% nuclear and 50% solar. Immediately this gets you out of needing the day/night batteries because nuclear generates at night. Then it's cloudy for a month and you lose half the solar generating capacity, but now you're only down 25% instead of 50%. Suppress demand by 20% through pricing and you only need enough long-term storage to cover 5% of the load.
This also makes the leveling a lot less precarious. If two weeks into the cloudy month it turns out you've already burned up all your long-term storage fuel and it's still cloudy, you can lean a little harder on pricing and get to a 25% reduction even if people gripe about it some. If that happens with pure solar, pricing high enough to cut demand by the full 50% would have people rioting in the streets.
Long term storage of the kind I'm talking about has two parts: a capacity part, and a consumable part. The capacity part is the same whether you need it for an hour or a month, and would be MUCH cheaper than nuclear plants of the same capacity. The consumable part (in my example, hydrogen) would be expensive, if needed for a month. But that doesn't happen very often, so on average the cost is quite reasonable.
It's gas because CO2 is not taxed. Don't tax gas and renewables will prop it up, but also nuclear doesn't stand a chance of competing. Tax CO2, and renewables will displace gas. The CO2 tax for renewables to take over will be lower than the CO2 tax needed for nuclear to take over. So the point you make there doesn't help new nuclear.
What CO2 taxes would do is keep existing nuclear plants operating a bit longer.
You _can't_ replace gas with intermittent. All sources aren't freely interchangeable. Intermittent doesn't work when the sun doesn't shine or when the wind doesn't blow, so you _need_ something to compensate it, and that's always gas.
Don't look at the system as "this source emits X kW when it's running". Look at the system as "the total demand _right now_ is Y xW, how can it be met ?". Because that's what drives the viability of sources of electricity, and whether they can be replaced with another one. Intermittent, by its very nature, isn't enough for producing electricity, it always needs an additional source.
It's always gas right now, because gas is the cheapest.
But if CO2 is taxed, hydrogen (from water electrolysis with surplus renewable electricity) becomes cheaper. And with cheap renewables, renewables + batteries + hydrogen would be cheaper than a system including nuclear.
> And with cheap renewables, renewables + batteries + hydrogen would be cheaper than a system including nuclear
* Definitely not. Looking at France, Solar and Wind are "cheap" because producers can sell on the grid, and the national operator _must_ buy it, at a higher cost than its own electricity, in a move to prop it up.
* Water electrolysis + electricity generation from hydrogen hasn't been proven to work cheaply at scale, what's the biggest project in existence ?
* Batteries are already not cost-effective at high scales
* All of those imply that storage will be on the same site as production; if not, the grid needs to be overhauled (it is built for few stable sources, not for numerous variable sources) and that cost is never taken into account by those who root for this kind of solutions
When I say renewables are cheap, I mean in comparison to NEW nuclear plants. Of course nuclear plants that already exist, where the sunk costs of construction can be ignored, will be more competitive. But France would spend less money building solar and wind instead of building new nuclear plants.
There is little electrolytic hydrogen today because hydrogen is mostly produced from chemical reforming of natural gas and other fossil fuels. Of course, this ignores the cost of CO2 emission from that process.
Batteries are already being installed in the real world, at very large scale. What exactly prevents them from being installed at even larger scale? And their costs are dropping rapidly, just as the cost of wind turbines and PV modules did.
