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...

As a supporter of nuclear, I think most nuclear supporters will be happy if we achieve carbon neutrality by any means.

But as other commenters pointed out, renewables are not achieving that in most places. According to Google, a staunchly anti-nuclear Germany has 6.95 tons per capita at 2023. France achieved that at 1986 (!!) and is now at 4.14.

It's really a question that should be directed at renewables: "If renewables are so cheap and fast to deploy, how come 39 years after Chernobyl, Germany still cannot get below France in CO2 emission?"

One thing to bear in mind about Europe is that to go carbon neutral you need to be able to deal with winters.

First of all they are darker than the US due to latitude, so solar during winter is basically a no go in half of the places where people actually live. I have rooftop solar and November - February it might as well not exist. One January it generated 20kWh for the whole month vs a peak of 70kWh per day in the summer. Wind is an option, but NIMBYism makes that hard as Europe doesn't have as much empty space as the US.

The other thing is heating: in Europe around 64% of residential energy use goes to space heating Vs 42% in the US. And the majority of that comes from gas. So to go carbon neutral, you actually need to greatly increase electricity demand. This is why Europe is pushing for new homes to be really well insulated.

The issue is that renewable tends to be intermittent and long-term storage is an open problem. You can do find in a day with battery but you can’t really produce a lot in the summer and use in winter.

It means you either need an alternative when production is too low such as coal or gas-fired power plants or a lot of capacity sufficiently stretched out than they are not stopped at the same time. Managing such a large grid with huge swings in capacity and making it resilient is a massive challenge. That’s why you end up with Germany building 70-ish new gas-fired power plants next to their alleged push towards renewable.

It’s probably doable but when you look at it from this angle nuclear starts to look good as an alternative.

The answer to this is just "intermittent" : the higher the share of renewables, the higher the share that you have to make up for when you're at night without wind. This can be done through batteries, water storage, or interconnection, but that's the real cost of renewables.

> Sure, it might cost more

I think this is more than good enough to be the "straight answer" you're looking for all on its own (& it's definitely not a case of "it might" - it definitely will).

However, on top of the cost, there's three additional reasons:

2. It will take longer

3. It will need to be geographically distributed to an extent that will incur a significantly broader variety of local logistical red tape & hurdles

4. One of the largest components that will cost more is grid balancing energy storage, which is not only a cost & logistical difficulty, but also an ongoing research area needing significant r&d investment as well.

Given all those comparators, it's a testament to the taboo that's been built up around nuclear that we have in fact been pursuing your "all renewable" suggestion anyway.

In theory, you can replace nuclear with a massive buildout of renewables and storage and grid upgrades and overcapacity to handle intermittency. The challenge is that doing all of that fast enough

There is just no good reason to build nuclear in a world with renewables.

Especially if you consider that most nations cannot produce fuel rods by themselves.

And if you calculate in the risk like “get me a insurance that covers leaks and melt downs” and finance somehow the disassembly of a nuclear plant, nuclear is one of the most costly ways you can get energy.

Plus it is a huge nice target in war times.

There are so so many benefits to decentralized renewables that you intuition is absolutely correct.

If Germany invested all their renewable money into nuclear, they would be carbon-neutral today. Not by 2050 but today.

Instead the CO2 per capita in Germany is 2x the one in France. And France had built their reactors in the 70s for a modest price.

The "whole load more renewable energy" idea is peak wishful thinking and it's incredible people still buy it today.

Nuclear has serious advantages over renewables when you consider the physical constraints: to match a large nuclear plant solely with wind or solar, you’d need far more land, material, and backup or storage to deal with intermittency. Renewable sources can’t reliably deliver the same baseload without huge infrastructure and/or major reductions in energy demand. The trade-offs make nuclear almost unavoidable if we want to decarbonize quickly while keeping stable power supply.

> in theory any amount of power a nuclear plant would generate could also be achieved with large amounts of renewables no?

You're exactly right, in theory, in practice it's impossible without some significant amount of energy storage, which we don't really have.

I once did this calculation for fun: in Italy, starting from the current energy mix and replacing fossils with more solar while meeting the demand in winter would require covering with panels an area equal to the region of Abruzzo (that's like 5% of Italy's total surface).

I don’t think it would cost more.

The real problem with nuclear energy is, and always has been the cost. It always seems to turn into a boondoggle.

There are a few things:

1. The electrical system was built for big power plants distributing the electricity to households. If you want to generate electricity a bit everywhere, you need to adapt the infrastructure. That's costly and it hasn't really been done at scale (whereas with nuclear plants it has).

2. With nuclear, you have great control over how much you produce. With renewables, you generally don't: you have electricity when there is wind or when there is sun. Batteries are not a solved problem at scale.

3. Renewable is cheap, but it depends on globalisation, which in turn depends on the abundance of fuel fossils. With nuclear, it's easier to have fewer dependencies. Which proportion of solar panels come from China?

4. Nuclear energy is very dense. Estimate how many solar panels you need to produce as much as a big nuclear plant, even without factoring in the batteries and the weather.

ignoring the fact that we live in the real world where money isn't infinite: nuclear provides stable base power generation, and it does it without taking up a lot of space.

Renewables produce power intermittently, and require storage to match demand. Storage either requires non-renewable resources like lithium, or else large amounts of land. in theory yes, any amount of power could be produced by renewables, but in practice renewables require other non-infinite resources to turn the power they generate into actual usable electricity coming out of your wall socket.

Yes? Any sort of system that generates power... can generate lots of power if there's more of that system.

What I find odd is that it has to be an all-or-nothing approach. Maybe sunny areas can do more with solar, great! But that won't work everywhere, and probably isn't a complete replacement anywhere. Other places that are cloudy, it might be better to go nuclear. Or even gas.

The regulations and the subsidies ought to be removed though, let the market decide. Solar or Nuclear will win if it's better, and that might be a per-area contest.

It would actually cost a lot less to use renewables and storage than a bunch of nuclear.

For a completely decarbinized grid, there are two paths: 1) 100% renewables plus storage, or 2) ~90% renewable plus storage, and 10% nuclear/advanced geothermal.

There's lots of debate about which one would be cheapest. But the true answer depends on how the cost curve of technologies develops over the coming 20 years. (Personally, I think 100% renewables will win because projections of all experts severely overestimate storage and renewables costs, while simultaneously severely underestimating the costs of nuclear. Renewables and storage are always over delivering, while nuclear always under delivers. So I think that trend will continue...)

You won't hear much about this in the popular media though, because they are too afraid of offending conservatives with politically incorrect facts. Sites like Ars Technica cover it though:

https://insideclimatenews.org/news/22092022/inside-clean-ene...

(just based on a little googling, don't shoot me if I'm wrong)

1 nuclear plant: 8 billion kilowatt hours/year

1 avg. wind turbine: 6 million kwh/yr, so 1300 turbines to match one nuke. It's obviously silly to bring up the Simpsons, but picturing 1300 turbines surrounding Springfield would be a funny visual gag.

Difficult to get numbers for solar plants because they vary wildly in size, but they seem to be commonly measured in tens of thousands, so napkin math suggest ~800,000 solar plants to match one nuclear plant.

Solar is awesome for reinforcing the grid and consumers; wind is neat but those turbines are only good for like twenty years. Nothing beats a nuke.

If you factor in all the cost usually externalised in nuclear power, it’s often a lot more expensive than people realise. Decommissioning nuclear waste and old reactors is a huge, time-consuming, and thus extremely expensive operation.

Can’t speak to other localities, but in the US, every additional project multiplies headaches with red tape, bureaucracy, cronyism, ideologically opposed politicians, sham environmental groups puppeted by incumbents, nearby residents taking issue with the project for whatever reason, etc. getting one project off the ground and landed safely is a monumental effort, let alone multiple.

Different energy product. And it doesn't preclude renewable energy from being deployed alongside.

This pitting of renewables vs nuclear is not helpful for renewables or nuclear. They both work well together.

I'm a nuclear supporter. I think we might be able to satisfy our energy needs with renewables. I am not entirely sure, because I'm not in the field. But, if it's true that renewables are so much cheaper, then self-interested individuals will invest in them. There is no need to be anti-nuclear.

People like me, who are pro-nuclear, do it because they believe that nuclear technology, like all technologies, could become much cheaper. Elon Musk was saying about rockets that in the end, with enough learning, the cost of building a rocket is only limited from below by the cost of the raw materials, so he though there is room to make rockets cheaper by a factor of 10 or 100. I think nuclear technology is the same; we can make it cheaper by a factor of 10 or 100. After all, we did that with solar and wind, didn't we?