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I think it's incorrect to say that nuclear does not require energy storage. The energy demand is not flat, it has peaks. If you don't flatten these peaks with

by cauch 4y ago

I think it's incorrect to say that nuclear does not require energy storage. The energy demand is not flat, it has peaks. If you don't flatten these peaks with storage, you need to build a production system that should be able to generate enough energy during the peak, but then, some of the generators will have to be turned off the rest of the time. To illustrate the idea, let me invent some numbers: with storage, you have, let's say, 10 power plants to build that are running relatively all the time, producing an integrated total of electricity of, let's say, 100. So, if you paid X$ for building the 10 power plants, you will have X/100 per unit of electricity. Without storage, you may end up with, let's say, 15 power plants, but some are turned off 90% of the time. At the end, you also produce an integrated total of electricity of 100 (the integral is the same, the time of consumption is just shifted to create peaks). The cost of build is now 1.5X, and you will have to 1.5X/100 per unit of electricity. On top of that, turning on and off a nuclear plant is less efficient than producing continuously, so the price of electricity increase even more. So, even with nuclear, storage needs to be built. Once the storage is built, it means that the problem of intermittence of renewable is way less problematic.

neilwilson 4y ago
You export the electricity. Either directly, or by bottling it. Excess power always has a use.
- cauch 4y ago
  Well, you cannot really export it if no one around needs it because they also are not in a peak. If they rely on importing electricity when in non-peak time, what do they do in peak time? By construction, the non-peak time is the worse time to export. Unless you export to a different part of the world, but then, the same argument works with renewable (said simply: if you can export at midnight to a country where it is 4pm, then you can use solar and import at midnight from a country where it is 4pm). What do you mean by "bottling it"? Do you mean storage? Because that's exactly what I'm saying.
  - ramesh31 4y ago
    >What do you mean by "bottling it"? Aluminum production, for one example. Bauxite is so cheap and abundant that the cost of aluminum is almost entirely in the electricity required for smelting. And because aluminum is such a critical material for industry, it is effectively equivalent to energy exportation. This is why tiny Iceland is a top 10 global exporter of it: abundant free geothermal energy with nowhere else to go.
    - cauch 4y ago
      Yes. It's basically demand response based on turning on and off factories.
    - nradov 4y ago
      No one is going to invest in an aluminum plant unless they have some assurance of cheap electric power for many years. The capital expense and fixed operating costs for those plants are tremendous. It's not economical to start and stop production on a daily basis as power prices fluctuate. How would you even schedule the production workers? And you still have to pay things like property taxes and insurance whether the plant is producing or not.
    - m4rtink 4y ago
      Also the local district heating company installed an electric 30 MW water heating boiler recently, which they can run on excess electric power and throttle down the regular combined cycle plant powered by natural gas.
- m4rtink 4y ago
  Also IIRC you can design the reactors to support a degree of output scaling, if not shutdown. IIRC French reactors are designed to do that - they have some issues right now with premature fatigue but I'm not sure it is related.
  - cauch 4y ago
    Yes, I believe it's the case. The French nuclear plants can do some load following. But they are not doing it, because it's more inefficient for a nuclear power plants, and as the nuclear is anyway not 100% of the mix, the load following is done by the other parts of the mix that don't have such problem. On my mind, the main problem of scaling down production for nuclear plant is that a nuclear plant is very expensive, and if it produces only at submaximal capacity, it means that the construction cost is spread on less electricity production.
  - moloch-hai 4y ago
    Operating a nuke at less than 100% is untenable: if run at 50%, each kWh costs twice as much as at 100%, but even running at 100%, it costs radically more than all other choices.
KennyBlanken 4y ago
Exactly. People who shout about how wind/solar are not reliable and need storage / fossil fuel backup and then spout about nuclear have no idea how grid-scale energy generation works. Nuclear takes hours to days to respond to load change, so there has to be much more reactive power available. And nuclear plants need to be able to draw megawatts of power from the grid any time they're not generating power. You can't "cold boot" a nuclear power plant without a massive external power supply and it takes days to weeks to do so. It's so bizarre hearing people advocating for nuclear talking about storage like it's some barely-understood, dangerous, hideously expensive sci-fi pipe dream. Grid-scale energy storage is almost 100 years old and battery based systems have been actively deployed for many years at all levels of the grid, right down to residential.
- peterfirefly 4y ago
  > Nuclear takes hours to days to respond to load change Days? Seriously? You know that is not true, don't you? The French nuclear power plants are an existence proof of that. Nuclear does need to be supplemented with something else with low construction/fixed costs for handling the rare, extreme peaks. That will most often be some sort of gas-powered plants. This has nothing to do with nuclear powers "inability" to "respond to load change" and everything to do with the cost of building enough nuclear power capacity that will almost never be used. On the other hand, we are still very, very far from being able to do really large-scale battery storage. We don't have the manufacturing capacity for the enormous number of battery cells needed and even if we did, the cost would be prohibitive. This will of course change for the better in the future but that is how things are for now.
  - cauch 4y ago
    I thought French nuclear were only doing base load, the load following part being done by other sources. I believe the French facilities have the capacity of doing load following, but are not doing it because it is less efficient (and therefore more expensive). So I would also not say "days", but it is also true that one cannot directly take a situation where nuclear has, so far, being used only for base load and pretend that load following will work exactly the same way. I'm not sure why you say "rare, extreme peaks": the current demand is non-flat every day, with a difference between the trough and peak that is typically ~50% of the peak. I agree that large scale battery storage is challenging. Maybe the solution would be to have some storage and some "wasted efficiency" by using nuclear plants in load following and turning them in stand-by every day during off-peak hours.
scythe 4y ago
Nuclear power needs storage on the scale of a day or two. Wind needs storage on the scale of a few weeks. Solar needs storage on the scale of 3-6 months. You can work around this a bit with demand scheduling and it's much less of a problem in the tropics, but we're talking about Japan: it's northern, densely populated and cloudy. If you can turn a nuclear plant off (summer) and on (winter) once a year, the storage requirement for solar drops by a lot.
- cauch 4y ago
  Sure, but 1) week storage and 3-6 months storage are extreme events, similar in probability as overlapping technical shutdowns in nuclear facilities. In practice, with interconnection, it is even arguable that such long term storage are even needed. 2) the technology built for short term storage is usually not that bad for medium term storage either. In any case, if you want a nuclear grid, you will need to invest in storage technology, and there is no reason the progress in those technology will only improve short term storage solutions. But I 100% agree: a nuclear plant turned on during winter will help. I'm not against nuclear, I just want to react to the incorrect view that storage is just a renewable problem.
- moloch-hai 4y ago
  There is, in fact, no need for "a few weeks" of storage anywhere for any reason, never mind months. NG backup works fine, and will continue working fine indefinitely. Storage cuts the fraction of time the furnace needs to run. Eventually, synthetic fuel will displace NG. It will be imported at need, same as NG today, but with no possibility of cartels.
- panick21_ 4y ago
  Nuclear really only needs storage for a few hours, exactly what existing LiIon is already really good at, quick charge, quick uncharge.

by cauch 4y ago

neilwilson 4y ago

You export the electricity. Either directly, or by bottling it. Excess power always has a use.

cauch 4y ago
Well, you cannot really export it if no one around needs it because they also are not in a peak. If they rely on importing electricity when in non-peak time, what do they do in peak time? By construction, the non-peak time is the worse time to export. Unless you export to a different part of the world, but then, the same argument works with renewable (said simply: if you can export at midnight to a country where it is 4pm, then you can use solar and import at midnight from a country where it is 4pm). What do you mean by "bottling it"? Do you mean storage? Because that's exactly what I'm saying.
- ramesh31 4y ago
  >What do you mean by "bottling it"? Aluminum production, for one example. Bauxite is so cheap and abundant that the cost of aluminum is almost entirely in the electricity required for smelting. And because aluminum is such a critical material for industry, it is effectively equivalent to energy exportation. This is why tiny Iceland is a top 10 global exporter of it: abundant free geothermal energy with nowhere else to go.
  - cauch 4y ago
    Yes. It's basically demand response based on turning on and off factories.
  - nradov 4y ago
    No one is going to invest in an aluminum plant unless they have some assurance of cheap electric power for many years. The capital expense and fixed operating costs for those plants are tremendous. It's not economical to start and stop production on a daily basis as power prices fluctuate. How would you even schedule the production workers? And you still have to pay things like property taxes and insurance whether the plant is producing or not.
  - m4rtink 4y ago
    Also the local district heating company installed an electric 30 MW water heating boiler recently, which they can run on excess electric power and throttle down the regular combined cycle plant powered by natural gas.
m4rtink 4y ago
Also IIRC you can design the reactors to support a degree of output scaling, if not shutdown. IIRC French reactors are designed to do that - they have some issues right now with premature fatigue but I'm not sure it is related.
- cauch 4y ago
  Yes, I believe it's the case. The French nuclear plants can do some load following. But they are not doing it, because it's more inefficient for a nuclear power plants, and as the nuclear is anyway not 100% of the mix, the load following is done by the other parts of the mix that don't have such problem. On my mind, the main problem of scaling down production for nuclear plant is that a nuclear plant is very expensive, and if it produces only at submaximal capacity, it means that the construction cost is spread on less electricity production.
- moloch-hai 4y ago
  Operating a nuke at less than 100% is untenable: if run at 50%, each kWh costs twice as much as at 100%, but even running at 100%, it costs radically more than all other choices.

KennyBlanken 4y ago

Exactly. People who shout about how wind/solar are not reliable and need storage / fossil fuel backup and then spout about nuclear have no idea how grid-scale energy generation works. Nuclear takes hours to days to respond to load change, so there has to be much more reactive power available. And nuclear plants need to be able to draw megawatts of power from the grid any time they're not generating power. You can't "cold boot" a nuclear power plant without a massive external power supply and it takes days to weeks to do so. It's so bizarre hearing people advocating for nuclear talking about storage like it's some barely-understood, dangerous, hideously expensive sci-fi pipe dream. Grid-scale energy storage is almost 100 years old and battery based systems have been actively deployed for many years at all levels of the grid, right down to residential.

peterfirefly 4y ago
> Nuclear takes hours to days to respond to load change Days? Seriously? You know that is not true, don't you? The French nuclear power plants are an existence proof of that. Nuclear does need to be supplemented with something else with low construction/fixed costs for handling the rare, extreme peaks. That will most often be some sort of gas-powered plants. This has nothing to do with nuclear powers "inability" to "respond to load change" and everything to do with the cost of building enough nuclear power capacity that will almost never be used. On the other hand, we are still very, very far from being able to do really large-scale battery storage. We don't have the manufacturing capacity for the enormous number of battery cells needed and even if we did, the cost would be prohibitive. This will of course change for the better in the future but that is how things are for now.
- cauch 4y ago
  I thought French nuclear were only doing base load, the load following part being done by other sources. I believe the French facilities have the capacity of doing load following, but are not doing it because it is less efficient (and therefore more expensive). So I would also not say "days", but it is also true that one cannot directly take a situation where nuclear has, so far, being used only for base load and pretend that load following will work exactly the same way. I'm not sure why you say "rare, extreme peaks": the current demand is non-flat every day, with a difference between the trough and peak that is typically ~50% of the peak. I agree that large scale battery storage is challenging. Maybe the solution would be to have some storage and some "wasted efficiency" by using nuclear plants in load following and turning them in stand-by every day during off-peak hours.

scythe 4y ago

Nuclear power needs storage on the scale of a day or two. Wind needs storage on the scale of a few weeks. Solar needs storage on the scale of 3-6 months. You can work around this a bit with demand scheduling and it's much less of a problem in the tropics, but we're talking about Japan: it's northern, densely populated and cloudy. If you can turn a nuclear plant off (summer) and on (winter) once a year, the storage requirement for solar drops by a lot.

cauch 4y ago
Sure, but 1) week storage and 3-6 months storage are extreme events, similar in probability as overlapping technical shutdowns in nuclear facilities. In practice, with interconnection, it is even arguable that such long term storage are even needed. 2) the technology built for short term storage is usually not that bad for medium term storage either. In any case, if you want a nuclear grid, you will need to invest in storage technology, and there is no reason the progress in those technology will only improve short term storage solutions. But I 100% agree: a nuclear plant turned on during winter will help. I'm not against nuclear, I just want to react to the incorrect view that storage is just a renewable problem.
moloch-hai 4y ago
There is, in fact, no need for "a few weeks" of storage anywhere for any reason, never mind months. NG backup works fine, and will continue working fine indefinitely. Storage cuts the fraction of time the furnace needs to run. Eventually, synthetic fuel will displace NG. It will be imported at need, same as NG today, but with no possibility of cartels.
panick21_ 4y ago
Nuclear really only needs storage for a few hours, exactly what existing LiIon is already really good at, quick charge, quick uncharge.