Comment by mikepavone
1 day ago
You totally can do it with some combination of overbuilding, storage and increased interconnection. It just starts to get expensive the higher the portion of your generation you want to supply with renewables. There's a good Construction Physics article[0] about this (though it simplifies by only looking at solar, batteries and natural gas plants and mostly does not distinguish between peaker and more baseload oriented combined cycle plants).
Personally, while I'm not opposed to nuclear, I'm pretty bearish on it. Most places are seeing nuclear get more expensive and not less. Meanwhile solar and batteries are getting cheaper. There's also the issue that nuclear reactors are generally most economical when operating with very high load factors (i.e. baseload generation) because they have high capital costs, but low fuel costs. Renewables make the net-demand curve (demand - renewable generation) very lumpy which generally favors dispatchable (peaker plants, batteries, etc.) generation over baseload.
Now a lot of what makes nuclear expensive (especially in the US) is some combination of regulatory posture and lack of experience (we build these very infrequently). We will also eventually hit a limit on how cheap solar and batteries can get. So it's definitely possible current trends will not hold, but current trends are not favorable. Currently the cheapest way to add incremental zero-carbon energy is solar + batteries. By the time you deploy enough that nuclear starts getting competitive on an LCOE basis, solar and batteries will probably have gotten cheaper and nuclear might have gotten more expensive.
[0] https://www.construction-physics.com/p/can-we-afford-large-s...
Thank you for this, this along with many other comments have really helped me understand.
This isn’t a simple issue, and I think your basic common sense take now mostly aligns with mine (though correct me if I’m wrong) which is something along the lines of that we don’t have to be anti-nuclear specifically but we do have to be bearish because it has downsides that mean if we are going to use it for some specific use case we’d better be sure that the pros are significant to outweigh the natural cons it brings with it.
> Renewables make the net-demand curve (demand - renewable generation) very lumpy which generally favors dispatchable (peaker plants, batteries, etc.) generation over baseload.
Even without renewables in the equation, the demand side of the curve is already extremely lumpy. If you're only affordable when you're operating near 100% of the time (i.e. "baseload") you simply can't make up the majority of power generation. Batteries are poised to change this - but at that point you've got to be cheaper than the intermittent power sources.
If the goal is 100% carbon-free energy, then we simply can't let economics get in the way. Otherwise we will always be stuck building some natural gas peaker plants.
And one option is to mass produce nuclear power plants, get prices down even further via economics of scale and then run them uneconomically.
Uneconomically doesn't mean "at a loss", just that you aren't making as much profit as you could optimally. With enough economics of scale, we can probably still run these nuclear plants at a profit, maybe even cheaper than natural gas peakers. But it doesn't matter, the goal is saving the planet, not profit.
It's not the only option, you can also build massive amounts of wind/solar/tidal and pair them with massive amounts of battery storage.
The third option is to build way more hydro power plants. Hydro tends to get overlooked as a form of green energy, because while it might be 100% renewable, you do have to "modify" a local ecosystem to construct a new dam. But hydro has the massive advantage that it can work as both baseload and demand load, so they can pair nicely with wind/solar/tidal.
I'm not even talking about pumped hydro (though, that's a fourth option to consider). Regular hydro can work as energy storage by simply turning the turbines off at letting the lakes fill up whenever there is sufficient power from your other sources.
Yeah, I'm just arguing that "baseload" should be understood to be a bad thing in my comment above.
If you want to argue that nuclear is affordable as non-baseload power, because the (non-economic) cost to the environment of the alternatives is otherwise too high.... well I'd disagree because of how far solar/wind/batteries have come in the last couple of years, but prior to that you would have had a point. And you still would as far as continuing to operate existing plants goes of course.
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... voters (or however we want to handwave preference aggregation) are very passive about carbon-free energy (and global warming and sustainability and economics and ...)
they either pick some pet peeves (coral reefs, rainforests, global South inequality, desertification) and usually start buying things (EVs, PV panels, heat pumps)
but when it comes to policy they usually revert to Greenpeace/degrowth/NIMBY cult members
This is not how nuclear works. Nuclear sets a low price that corresponds to its cost, then lets more expensive marginal energy sources set the final price. Nuclear can by the way be modulated +20%\-20%, which makes it quite flexible in real condition. See https://www.rte-france.com/en/eco2mix/power-generation-energ... as a proof - nuclear generation in France can go from 25GW to 45GW during a day.
New small modular reactors promise great improvements, as they can be pre-built in factories, require limited maintenance, lower risk, and as a result much lower cost per MW.
https://www.rolls-royce.com/innovation/small-modular-reactor...
> This is not how nuclear works. Nuclear sets a low price that corresponds to its cost, then lets more expensive marginal energy sources set the final price.
This may be an accurate description for fully-depreciated nuclear plants, but it doesn't reflect the economics of new-build nuclear at all. You have to consider both operating and capital costs. Nuclear plants are cheap to operate once built, but those operations have to pay off the capital costs. If the load factor is low, then each unit of generated power has to bear a higher portion of the capital costs. If your capital costs are very high, then you either need a very high load factor or very high spot prices to bear those costs.
> Nuclear can by the way be modulated +20%\-20%
Net demand on CAISO can go from about 2 MW to 30 MW in the summer. 20 MW of that ramp occurs over just 3 hours. I'm sure you can build nuclear plants that ramp that fast, but you need a lot more than the range you're mentioning here. Regardless, I'm not making an argument about the physics of nuclear power plants, just the economics. Expensive plants generally need high load factors to pay off the capital costs.
> nuclear generation in France can go from 25GW to 45GW during a day.
Most of France's nuclear plants are old and thus fully depreciated. The only one built recently (Flamanville Unit 3), is a good example of the bad cost trend in nuclear. While this was a bit cheaper than Vogtle Units 3 and 4 in the US on a dollars per nameplate capacity basis, at 19 billion euro it's still very expensive (and also way over budget).
France also has high rates of curtailment, which is not necessarily a huge problem for them since so much of their generation is already carbon-free, but it does suggest they're already hitting the limits of their ability to ramp production up and down. Whether this is an engineering problem or something to do with the structure of their electricity market is a bit unclear to me
> New small modular reactors promise great improvements, as they can be pre-built in factories, require limited maintenance, lower risk, and as a result much lower cost per MW.
This has been the promise for years, but so far the low costs have yet to materialize and they are estimated to have a higher LCOE than traditional plants. Currently only 2 are actually operational, a demonstration plant in China and a floating power plant using adapted ice-breaker reactors in Russia. There are a few more in the pipeline, but they are all at least a couple years out from actually producing power.
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The massive capital costs of the plant have to be paid back in the sale price of energy, that’s what makes it expensive. France’s state built plants don’t have that accounting
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Deploying a continental renewable mix (wind, solar...) reduces the effets of 'intermittency' on electricity production.
https://ourworldindata.org/grapher/electricity-fossil-renewa... (explore many nations/regions)
He will soon be dead, Jim.