Nuclear power is good for its consistent output that is independent of outside factors like wind, clouds, or drought. Plus much of the cost of nuclear is tied with the construction of the plant not the operating costs, so a paid off plant isn’t particularly expensive.
Plus much of the cost of nuclear is tied with the construction of the plant not the operating costs, so a paid off plant isn’t particularly expensive.
I wish that were true. Nuclear plants built in the 60s and 70s (but still operating today) was losing money in Ohio. So the power companies bribed the Republican Ohio Speaker of the House $60 million dollars to pass a law that citizens have to pay extra fees totally over $1 billion dollars to power plants so that power companies can make a profit on nuclear. The bill was passed, and signed into law by the governor of Ohio, and years passed before the investigation found the bribery scandal.
That former Ohio Speaker of the House was sentenced to 20 years in prison finally.
They’ve had to keep upgrading them - the percentage of nuclear is the same, but no new plants have been built, so that extra power has come from research on how close to the red line they can actually run.
A coal power plant is rougly the same cost per GW as solar or wind, doesn’t mean we should build more of them.
I agree it’s expensive, but so were solar and wind a couple decades ago. Government investment helped research, development, scaling up - imagine if that had been done in the '80s, we wouldn’t be building natural gas plants right now.
I agree it’s expensive, but so were solar and wind a couple decades ago. Government investment helped research, development, scaling up - imagine if that had been done in the '80s
The first commercial nuclear power plant in the USA came online in 1958. source That’s 66 years ago. If time was going to make it cheaper we would have seen that by now. Instead the most recent reactors to come online, which occurred just this year, were projected to cost $14 billion and instead are cost $31 billion! Even worst, this isn’t an entirely new nuclear power plant, its just two additional reactors at an existing operational plant. source
Nuclear just costs too much for what you get at the end.
Ah, perhaps my source was off. Thanks for the additional data.
But looking at it another way, nuclear is less than twice coal. Estimating the cost of that georgia plant would put it at $16-17B, so those overruns would be atypical.
Without investment, it’s going to stay just as expensive. And the main regulating body not having a mandate to develop the technology has just been holding us back.
Here’s the summary for the wikipedia article you mentioned in your comment:
Different methods of electricity generation can incur a variety of different costs, which can be divided into three general categories: 1) wholesale costs, or all costs paid by utilities associated with acquiring and distributing electricity to consumers, 2) retail costs paid by consumers, and3) external costs, or externalities, imposed on society. Wholesale costs include initial capital, operations & maintenance (O&M), transmission, and costs of decommissioning. Depending on the local regulatory environment, some or all wholesale costs may be passed through to consumers. These are costs per unit of energy, typically represented as dollars/megawatt hour (wholesale). The calculations also assist governments in making decisions regarding energy policy. On average the levelized cost of electricity from utility scale solar power and onshore wind power is less than from coal and gas-fired power stations,: TS-25 but this varies a lot depending on location.: 6–65
That consistent output isn’t as useful as you think. Solar and wind are ridiculously cheap, so we would want to use them when they’re available. That means winding down nuclear plants when those two spin up. I’m turn, that means those initial construction costs you mentioned aren’t being efficiently ammortized over the entire life of the plant.
What we can do instead is take historical sun and wind data for a given region, calculate where the biggest trough will be, and then build enough storage capacity to cover it. Even better, aim for 95% coverage in the next few years, with the rest taken up by existing natural gas. There’s some non-linear factors involved where getting to 100% is a lot harder than 95%.
This is the trap. The fossil fuel industry has co-opted wind and PV solar by way of filling in the gaps and transitioning to net zero emissions. Of course, the gaps will always be there and the transition will never complete and “net zero” seems to just leave the door open on fossil fuels forever.
Nuclear power, on the other hand, has the reliability that @FireTower@lemmy.world mentioned and it closes any of the gaps from wind and solar right up. You don’t have to quickly cut the power on a reactor if it’s sunny or windy, just divert it to hydrogen and ammonia production. Even if the efficient high temperature electrolysis tech isn’t ready yet, it doesn’t really matter since it’s emissions free. Furthermore, nuclear power produces good heat/steam to support cogeneration and various industrial processes.
Nonsense. Conservatives have brought up nuclear for decades as a way to play “gotcha” with anti-nuclear progressives. Maggie Thatcher, for example, embraced the science of climate change early on as a way to push nuclear. It was never serious, though. Always a political game that resulted in no new nuclear being built while coal and oil continued to ramp up.
I think Thatcher just wanted to privatize, deregulate, and liberalize as much as she could, all fundamentally bad moves from the perspectives of both labor and greenhouse emissions concerns.
There are several lines of storage research that only need to be ramped up to mass production at this point. Since stationary storage doesn’t have the weight restrictions that electric car batteries do, there are many different viable options. Flow batteries, sodium batteries, pumping water uphill, big tower of concrete blocks on pullies, hydrogen electrolysis, big ceramic block that gets hot. Some will work wherever, others are only viable in certain situations, but there are many options and we only need one of them to work at scale.
When nuclear tries to make improvements, it tends to do one thing per decade. If it fails, wait another decade to try the next thing. Last decade, it was the AP1000 reactor. It was hoped it would make a single, repeatable design that would avoid the boutique engineering that caused budget and schedule overruns in the past. Didn’t work out that way. This decade, it’s Small Modular Reactors. The recent collapse of the Utah project doesn’t give much hope for it.
Even if it does, it won’t be proven out before 2030. We’ll want to be on 90% clean electrical technology by then if we have even a hope of keeping climate change at bay. There is no longer a path with nuclear that could do so. Given project construction times, the clock ran out already.
I think most of the technologies you mention are currently still too expensive, can’t be used everywhere or don’t make sense to be used at a large scale. E.g. for pumped hydro you need height differences. Concrete blocks on pullies sound like you need a lot of space for only a small amount of energy (I didn’t do the maths, this is just my feeling, so correct me if I’m wrong).
About nuclear energy: in the article I saw that it accounts for 18% of the US electricity production. That’s half of the 40% emissions-free part.
So for sure we cannot reach the targets without nuclear energy.
My opinion is that we should keep using it and keep investigating it further, just as we should keep investigating new electricity storage technologies.
Some of those technologies are only awaiting mass production. Economies of scale are all that’s needed, not any further breakthroughs in the lab.
The part of that carbon-free total that isn’t nuclear or hydro has almost all been installed on the last decade. It got deployed fast and is only accelerating.
Pumped hydro works well for storage, although it basically has the same problem as hydro power - it’s only available in places with water and elevation changes.
Here’s the summary for the wikipedia article you mentioned in your comment:
Kruonis Pumped Storage Plant (the KPSP) is located near Kruonis, Lithuania, 34 km (21 mi) east of Kaunas. Its main purpose isto provide grid energy storage. It operates in conjunction with the Kaunas Hydroelectric Power Plant. During periods of low demand, usually at night, Kruonis PSHP raises water from the lower Kaunas reservoir to the upper one using cheap surplus energy. The station is designed to have an installed capacity of1,600 MW but only four 225 MW generators are currently operational. With a fully filled upper reservoir the plant can generate 900 MW for about 12 hours. The KPSP uses hydro-resources of artificial water pools existing at different geographical levels. The electricity from this power plant is supplied to a 330 kV electricity line to Elektrėnai, where the largest fossil fuel plant in Lithuania is operating, and Kaunas. During a surplus of electricity generation, the KPSP uses the surplus electricity to pump water from the lower pool to the upper pool. During an electricity output deficit, the Kruonis PSP operates as a regular hydro power plant, letting water flow from the upper pool to the lower pool to generate additional electricity. With a fully filled upper reservoir the plant can generate 900 MW for about 12 hours. Kruonis Plant is the only pumped-storage station in the Baltic states.The Kruonis PSP Industrial Park and Kruonis Technology Park were created as the location, infrastructure and low electricity price are attractive for data centers.A neighbourhood for workers of the Kruonis pumped storage plant plant was built in the 1980sand early 1990sin Elektrėnai, expanding this city of specialists in energetics by area and inhabitants roughly twice.
Don’t forget power companies can also work with smart thermostat manufacturers and car manufacturers to implement demand side tweaks to reduce power consumption. If they need to drop demand by some number of megawatts, they can adjust everyone’s thermostate by 1 degree temporarily and easily meet that need, or slow electric car charging by half a kilowatt. As long as there’s a manual override for users who need to charge right then or need to change the thermostat right then, this can easily make a significant dent in the variability of the grid with renewables
It does not make sense to compare the price of energy storage (lithium batteries), with the price for generating electricity (nuclear energy), or do you mean something else?
People have a hard-on about nuclear being “baseload” power and renewables being intermittent. Solar/wind plus batteries to add dispatchability is a valid comparison to nuclear if you only want to talk about baseload.
If every home was a battery instead of an armory that would be a really cool redundant storage infrastructure. Likely not financially viable compared to centralized storage but it would be kind of cool if their was no immediate central reliance on power so any interruption in power generation could withstand say 1 week of storage reserves nation wide before outages started trickling off to support say hospitals, heating above 40 degrees, etc. Entirely too complicated I’m sure but just a neat thought I had after reading your comment.
I totally agree with this. A lot of places have cheap electricity in off-peak hours, as a workaround to this limitation (steady output).
I think that this obsession about intermittent power comes partially from the idea that any new sources of power must be drop-in replacements for the systems that we’ve had for so many decades. However those systems run the way they do as an accident of technology, not because of a careful analysis and design to match optimal usage patterns.
im assuming by “winding down” you mean production of power? Not shutting down the plants, nuclear plants operate the most efficiently at high capacity factor, when they aren’t producing power the fuel is still decaying, thus you should be producing power for AS LONG as possible. This is why if you ever look at capacity factor >80% is really common, i’ve even seen >100% a couple of times, as well as the term “baseload plant” being used almost always in reference to nuclear.
That wouldn’t make sense for an existing nuclear plant, the nuclear plant should stay running in place of solar/wind. As you would be burning money actively otherwise, or you could just shut it down permanently, thats the other option.
Yes, running them at a lower level, and yes, that would be my point. You can run them down when renewable sources pick up, but that’s inefficient. Solar/wind don’t mix well with nuclear; you’re leaving something on the table if you try.
That’s not a particularly complex way of looking at it. the nuclear plant is a base load plant, meaning you can pretty much just subtract its output from the predicted consumption, and then you can simply have less renewable energy, load peaking is midday anyway, which is when solar is productive. (or have less energy storage, since the nuclear plant will combat that), you would have a more consistent and regular power production at that point, and waste less money. (since you aren’t burning money on running a nuclear plant at a reduced/no output, you would technically be burning solar energy (you cant burn wind energy, you just stop the turbine, and it wont produce power) but that’s cheaper anyway, and besides beyond install costs, very low continual maintenance)
Though if you were going to shutdown the nuclear plant at its EOL then you would need to increase production of renewables, which is easy enough. Saying that “nuclear and solar/wind don’t mix” is just kind of weird. Realistically the only better mix would be solar/wind and gas since gas can manage peak loads super trivially, which is of course not very green. So arguably nuclear would be your ideal match unless you went explicitly solar/wind.
Consistent output is certainly useful when you break down demand into a constant demand + variable demand. For instance, if demand is typically 200-350 kWh, you could build a nuclear plant to generate 200 kWh and constantly run while you meet the varying 0-150 kWh demand with wind and solar.
I will agree though that we need to run numbers on this to determine the best approach. I don’t have a feel for what wins out if we make larger solar and wind farms – increased cost for the additional capacity, or increased efficiency from economies of scale.
Don’t leave out the deconstruction of old nuclear plants after their operational time and the storage of radioactive waste. It’s very laborious and expensive.
Also, having nuclear in a 100% low carbon grid is great to stabilize the grid.
A French study showed that having around 13% of nuclear in the grid reduce the solar and battery capacity needed by a factor of two compared to no nuclear.
Nuclear power is bad for its consistent output because demand is not constant. You could of course run some energy hungry chemical reaction when there is more power than demand, make hydrogen to use for synthetic fuels for example or build a battery to store the excess power for when the demand is high. But is is of course much cheaper with renewables.
Total demand is not constant, but you can represent total demand as a sum of a given constant demand plus variable demand. Say for instance the average demand varies from 200-350 kWh a year. You could run nuclear power plants to generate 200 kWh worth of electricity, and use solar/wind for the remaining 0-150 kWh demand. It would be fairly efficient to have nuclear provide a base load of some kind while solar and wind vary to meet the full demand.
Nuclear power is good for its consistent output that is independent of outside factors like wind, clouds, or drought. Plus much of the cost of nuclear is tied with the construction of the plant not the operating costs, so a paid off plant isn’t particularly expensive.
I wish that were true. Nuclear plants built in the 60s and 70s (but still operating today) was losing money in Ohio. So the power companies bribed the Republican Ohio Speaker of the House $60 million dollars to pass a law that citizens have to pay extra fees totally over $1 billion dollars to power plants so that power companies can make a profit on nuclear. The bill was passed, and signed into law by the governor of Ohio, and years passed before the investigation found the bribery scandal.
That former Ohio Speaker of the House was sentenced to 20 years in prison finally.
The bad bribed-passed law is still on the books in Ohio and citizens are still paying extra to artificially make nuclear profitable for the power company. Here’s just a small source for the whole sorted story..
So no, even old built nuclear power plants are still more expensive that nearly all other electricity sources in the USA.
They’ve had to keep upgrading them - the percentage of nuclear is the same, but no new plants have been built, so that extra power has come from research on how close to the red line they can actually run.
New reactors just came online in Georgia this year. A $15 billion dollar planned project that cost $30 billion with overruns.
So new or old, nuclear is really expensive electricity.
A coal power plant is rougly the same cost per GW as solar or wind, doesn’t mean we should build more of them. I agree it’s expensive, but so were solar and wind a couple decades ago. Government investment helped research, development, scaling up - imagine if that had been done in the '80s, we wouldn’t be building natural gas plants right now.
Incorrect. Costs listed per KW of generation:
source
The first commercial nuclear power plant in the USA came online in 1958. source That’s 66 years ago. If time was going to make it cheaper we would have seen that by now. Instead the most recent reactors to come online, which occurred just this year, were projected to cost $14 billion and instead are cost $31 billion! Even worst, this isn’t an entirely new nuclear power plant, its just two additional reactors at an existing operational plant. source
Nuclear just costs too much for what you get at the end.
Ah, perhaps my source was off. Thanks for the additional data.
But looking at it another way, nuclear is less than twice coal. Estimating the cost of that georgia plant would put it at $16-17B, so those overruns would be atypical.
But my main point on cost is that government investment has been lacking in nuclear compared to renewables: https://www.forbes.com/sites/robertbryce/2021/12/27/why-is-solar-energy-getting-250-times-more-in-federal-tax-credits-than-nuclear/?sh=4a783c3221cf
Without investment, it’s going to stay just as expensive. And the main regulating body not having a mandate to develop the technology has just been holding us back.
Here’s the summary for the wikipedia article you mentioned in your comment:
Different methods of electricity generation can incur a variety of different costs, which can be divided into three general categories: 1) wholesale costs, or all costs paid by utilities associated with acquiring and distributing electricity to consumers, 2) retail costs paid by consumers, and 3) external costs, or externalities, imposed on society. Wholesale costs include initial capital, operations & maintenance (O&M), transmission, and costs of decommissioning. Depending on the local regulatory environment, some or all wholesale costs may be passed through to consumers. These are costs per unit of energy, typically represented as dollars/megawatt hour (wholesale). The calculations also assist governments in making decisions regarding energy policy. On average the levelized cost of electricity from utility scale solar power and onshore wind power is less than from coal and gas-fired power stations,: TS-25 but this varies a lot depending on location.: 6–65article | about
Besides maybe coal
That consistent output isn’t as useful as you think. Solar and wind are ridiculously cheap, so we would want to use them when they’re available. That means winding down nuclear plants when those two spin up. I’m turn, that means those initial construction costs you mentioned aren’t being efficiently ammortized over the entire life of the plant.
What we can do instead is take historical sun and wind data for a given region, calculate where the biggest trough will be, and then build enough storage capacity to cover it. Even better, aim for 95% coverage in the next few years, with the rest taken up by existing natural gas. There’s some non-linear factors involved where getting to 100% is a lot harder than 95%.
This is the trap. The fossil fuel industry has co-opted wind and PV solar by way of filling in the gaps and transitioning to net zero emissions. Of course, the gaps will always be there and the transition will never complete and “net zero” seems to just leave the door open on fossil fuels forever.
Nuclear power, on the other hand, has the reliability that @FireTower@lemmy.world mentioned and it closes any of the gaps from wind and solar right up. You don’t have to quickly cut the power on a reactor if it’s sunny or windy, just divert it to hydrogen and ammonia production. Even if the efficient high temperature electrolysis tech isn’t ready yet, it doesn’t really matter since it’s emissions free. Furthermore, nuclear power produces good heat/steam to support cogeneration and various industrial processes.
Nonsense. Conservatives have brought up nuclear for decades as a way to play “gotcha” with anti-nuclear progressives. Maggie Thatcher, for example, embraced the science of climate change early on as a way to push nuclear. It was never serious, though. Always a political game that resulted in no new nuclear being built while coal and oil continued to ramp up.
I think Thatcher just wanted to privatize, deregulate, and liberalize as much as she could, all fundamentally bad moves from the perspectives of both labor and greenhouse emissions concerns.
The problem is that there are currently no good (cheap, scalable) technologies to store these large amounts of electrical energy.
There are several lines of storage research that only need to be ramped up to mass production at this point. Since stationary storage doesn’t have the weight restrictions that electric car batteries do, there are many different viable options. Flow batteries, sodium batteries, pumping water uphill, big tower of concrete blocks on pullies, hydrogen electrolysis, big ceramic block that gets hot. Some will work wherever, others are only viable in certain situations, but there are many options and we only need one of them to work at scale.
When nuclear tries to make improvements, it tends to do one thing per decade. If it fails, wait another decade to try the next thing. Last decade, it was the AP1000 reactor. It was hoped it would make a single, repeatable design that would avoid the boutique engineering that caused budget and schedule overruns in the past. Didn’t work out that way. This decade, it’s Small Modular Reactors. The recent collapse of the Utah project doesn’t give much hope for it.
Even if it does, it won’t be proven out before 2030. We’ll want to be on 90% clean electrical technology by then if we have even a hope of keeping climate change at bay. There is no longer a path with nuclear that could do so. Given project construction times, the clock ran out already.
I think most of the technologies you mention are currently still too expensive, can’t be used everywhere or don’t make sense to be used at a large scale. E.g. for pumped hydro you need height differences. Concrete blocks on pullies sound like you need a lot of space for only a small amount of energy (I didn’t do the maths, this is just my feeling, so correct me if I’m wrong).
About nuclear energy: in the article I saw that it accounts for 18% of the US electricity production. That’s half of the 40% emissions-free part. So for sure we cannot reach the targets without nuclear energy. My opinion is that we should keep using it and keep investigating it further, just as we should keep investigating new electricity storage technologies.
Some of those technologies are only awaiting mass production. Economies of scale are all that’s needed, not any further breakthroughs in the lab.
The part of that carbon-free total that isn’t nuclear or hydro has almost all been installed on the last decade. It got deployed fast and is only accelerating.
Pumped hydro works well for storage, although it basically has the same problem as hydro power - it’s only available in places with water and elevation changes.
Yes, but an elevation change of 100 meters is enough for one: The one near me for example
Interesting! Still way too much elevation needed to be useful for us in Holland though. 😆
Here’s the summary for the wikipedia article you mentioned in your comment:
Kruonis Pumped Storage Plant (the KPSP) is located near Kruonis, Lithuania, 34 km (21 mi) east of Kaunas. Its main purpose is to provide grid energy storage. It operates in conjunction with the Kaunas Hydroelectric Power Plant. During periods of low demand, usually at night, Kruonis PSHP raises water from the lower Kaunas reservoir to the upper one using cheap surplus energy. The station is designed to have an installed capacity of 1,600 MW but only four 225 MW generators are currently operational. With a fully filled upper reservoir the plant can generate 900 MW for about 12 hours. The KPSP uses hydro-resources of artificial water pools existing at different geographical levels. The electricity from this power plant is supplied to a 330 kV electricity line to Elektrėnai, where the largest fossil fuel plant in Lithuania is operating, and Kaunas. During a surplus of electricity generation, the KPSP uses the surplus electricity to pump water from the lower pool to the upper pool. During an electricity output deficit, the Kruonis PSP operates as a regular hydro power plant, letting water flow from the upper pool to the lower pool to generate additional electricity. With a fully filled upper reservoir the plant can generate 900 MW for about 12 hours. Kruonis Plant is the only pumped-storage station in the Baltic states.The Kruonis PSP Industrial Park and Kruonis Technology Park were created as the location, infrastructure and low electricity price are attractive for data centers.A neighbourhood for workers of the Kruonis pumped storage plant plant was built in the 1980s and early 1990s in Elektrėnai, expanding this city of specialists in energetics by area and inhabitants roughly twice.article | about
Don’t forget power companies can also work with smart thermostat manufacturers and car manufacturers to implement demand side tweaks to reduce power consumption. If they need to drop demand by some number of megawatts, they can adjust everyone’s thermostate by 1 degree temporarily and easily meet that need, or slow electric car charging by half a kilowatt. As long as there’s a manual override for users who need to charge right then or need to change the thermostat right then, this can easily make a significant dent in the variability of the grid with renewables
Even current lithium-based battery storage is already cheaper than nuclear.
It does not make sense to compare the price of energy storage (lithium batteries), with the price for generating electricity (nuclear energy), or do you mean something else?
People have a hard-on about nuclear being “baseload” power and renewables being intermittent. Solar/wind plus batteries to add dispatchability is a valid comparison to nuclear if you only want to talk about baseload.
If every home was a battery instead of an armory that would be a really cool redundant storage infrastructure. Likely not financially viable compared to centralized storage but it would be kind of cool if their was no immediate central reliance on power so any interruption in power generation could withstand say 1 week of storage reserves nation wide before outages started trickling off to support say hospitals, heating above 40 degrees, etc. Entirely too complicated I’m sure but just a neat thought I had after reading your comment.
I totally agree with this. A lot of places have cheap electricity in off-peak hours, as a workaround to this limitation (steady output).
I think that this obsession about intermittent power comes partially from the idea that any new sources of power must be drop-in replacements for the systems that we’ve had for so many decades. However those systems run the way they do as an accident of technology, not because of a careful analysis and design to match optimal usage patterns.
I appreciate seeing a serious, well thought out comment posted from a lemmynsfw account!
im assuming by “winding down” you mean production of power? Not shutting down the plants, nuclear plants operate the most efficiently at high capacity factor, when they aren’t producing power the fuel is still decaying, thus you should be producing power for AS LONG as possible. This is why if you ever look at capacity factor >80% is really common, i’ve even seen >100% a couple of times, as well as the term “baseload plant” being used almost always in reference to nuclear.
That wouldn’t make sense for an existing nuclear plant, the nuclear plant should stay running in place of solar/wind. As you would be burning money actively otherwise, or you could just shut it down permanently, thats the other option.
Yes, running them at a lower level, and yes, that would be my point. You can run them down when renewable sources pick up, but that’s inefficient. Solar/wind don’t mix well with nuclear; you’re leaving something on the table if you try.
That’s not a particularly complex way of looking at it. the nuclear plant is a base load plant, meaning you can pretty much just subtract its output from the predicted consumption, and then you can simply have less renewable energy, load peaking is midday anyway, which is when solar is productive. (or have less energy storage, since the nuclear plant will combat that), you would have a more consistent and regular power production at that point, and waste less money. (since you aren’t burning money on running a nuclear plant at a reduced/no output, you would technically be burning solar energy (you cant burn wind energy, you just stop the turbine, and it wont produce power) but that’s cheaper anyway, and besides beyond install costs, very low continual maintenance)
Though if you were going to shutdown the nuclear plant at its EOL then you would need to increase production of renewables, which is easy enough. Saying that “nuclear and solar/wind don’t mix” is just kind of weird. Realistically the only better mix would be solar/wind and gas since gas can manage peak loads super trivially, which is of course not very green. So arguably nuclear would be your ideal match unless you went explicitly solar/wind.
Consistent output is certainly useful when you break down demand into a constant demand + variable demand. For instance, if demand is typically 200-350 kWh, you could build a nuclear plant to generate 200 kWh and constantly run while you meet the varying 0-150 kWh demand with wind and solar.
I will agree though that we need to run numbers on this to determine the best approach. I don’t have a feel for what wins out if we make larger solar and wind farms – increased cost for the additional capacity, or increased efficiency from economies of scale.
Hydro is also quite independent but it’s heavily dependent on geography. That’s how Canada is able to be much ahead in renewable energy.
Don’t leave out the deconstruction of old nuclear plants after their operational time and the storage of radioactive waste. It’s very laborious and expensive.
Also, having nuclear in a 100% low carbon grid is great to stabilize the grid.
A French study showed that having around 13% of nuclear in the grid reduce the solar and battery capacity needed by a factor of two compared to no nuclear.
Nuclear power is bad for its consistent output because demand is not constant. You could of course run some energy hungry chemical reaction when there is more power than demand, make hydrogen to use for synthetic fuels for example or build a battery to store the excess power for when the demand is high. But is is of course much cheaper with renewables.
Total demand is not constant, but you can represent total demand as a sum of a given constant demand plus variable demand. Say for instance the average demand varies from 200-350 kWh a year. You could run nuclear power plants to generate 200 kWh worth of electricity, and use solar/wind for the remaining 0-150 kWh demand. It would be fairly efficient to have nuclear provide a base load of some kind while solar and wind vary to meet the full demand.
Hydro is best as a giant battery bank, and pairs quite well with nuclear.