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Nuclear power plants are currently too expensive to not be used at 100% all the time (except when you need to perform maintenance). Some nuclear power plants ar

Nuclear power plants are currently too expensive to not be used at 100% all the time (except when you need to perform maintenance). Some nuclear power plants are designed to be able to load follow, but in practice they don't do it. Batteries will never be cheap enough to allow for seasonal storage. They are good for day-to-night storage. For seasonal fluctuations, the best you can do is natural gas. If we convert all our energy to solar, wind, hydro, and natural gas for peaker plants, we'd be comfortably net negative. In fact, right now in the US the CO2 absorption by forests is equal to all the emissions produced by the natural gas power plants (which are mostly used full time, not in peaker mode). Of course, the US produces a lot of emissions from transportation and industry. But they can be electrified in time, and the coal power plants can be eliminated, and the natural gas plants kept as peaker plants only. The path to net zero, or net negative, does not strictly speaking need nuclear energy. I personally am a huge fan of nuclear, but I acknowledge that it is not really needed to fight climate change.

kragen 3y ago
i agree with almost everything in your cogent and well-informed comment, with only two exceptions: - forests can only increase in biomass up to some relatively low limit; you may be correct that in the usa they currently absorb more than gas plants emit, but that is not a sustainable situation, unless you start cutting them down and sequestering the carbon - you can get pretty far covering seasonal fluctuations with simple overprovisioning also i think you're not taking into account the likely advent of mass production of synfuel
- credit_guy 3y ago
  > unless you start cutting them down and sequestering the carbon We actually do that all the time: we cut down trees and make houses. Here's a number from the US Forest Service [1] that as of 2009 the US was using 187 million m3 of solid wood products. > you can get pretty far covering seasonal fluctuations with simple overprovisioning Fully agree. > likely advent of mass production of synfuel I'm extremely pessimistic about that. The best hope is for hydrogen, but even that looks all but hopeless to me, if you don't count "blue hydrogen". [1] https://www.fs.usda.gov/research/treesearch/33882 https://www.fs.usda.gov/research/treesearch/33882
  - kragen 3y ago
    187 million m³ of solid wood products is on the order of 187 million tonnes of carbon dioxide, which is an insignificantly small number in this context currently we need to sequester 950 gigatonnes of carbon dioxide, or about 300 gigatonnes of carbon, to get back to pre-industrial levels. this number increases by 40 gigatonnes carbon dioxide or 13 gigatonnes carbon per year https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere#Current_situation https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_at... so roughly we need to sequester 1500 times as much carbon dioxide as the us forest service number, every year. so if the usa builds enough wood housing and other buildings for 450 billion people next year, and another 450 billion people the year after that, and so on indefinitely, that would compensate for current carbon emissions but this is not a plausible plan by contrast, direct air capture followed by injection into the crust where carbonatation of olivine and similar minerals sequesters the carbon is a plausible plan, but one that will require a lot of energy why are you extremely pessimistic about mass production of synfuel? fischer-tropsch produced 25% of germany's wartime automotive fuel, though of course that was starting from coal rather than carbon dioxide: https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process#History https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces...
    - credit_guy 3y ago
      I don't think like that, and nobody thinks like that. The first target before we think about getting back to preindustrial levels, is to get to net zero by 2050. If you start measuring things against a goal that's too distant in the future, you just give up. Ok, if we talk net zero, then the what does it take the US to do that? The US is not the entire globe. Currently the US emits about 6.34 gigatons of CO2-equivalent and absorbs about 754 megatons for a net of 5.59 gigatons CO2e [1]. The emissions from natural gas power generation are at 743 megatons [2]. If we could eliminate all other emissions except for the ones from the natural gas power plants, we'd already be slightly net negative. If we could keep the existing natural gas power plants, but run them only as peaker plants, we'd be well into negative territory. You are saying that 754 megatons is not sustainable without some program of carbon sequestration. I pointed out that 14 years ago the US consumed 187 million m3 of solid wood, which is of the order of 187 megatons of CO2 sequestration. Or about 25% of the annual CO2 absorption by all the US forests and grasslands. To me that sounds like a pretty huge rotation speed, and certainly sustainable in the long run. > by contrast, direct air capture followed by injection into the crust where carbonatation of olivine and similar minerals sequesters the carbon is a plausible plan It's a plausible plan, but that's about it. The facts on the ground are that we don't do it for some reason. Most likely there are some serious obstacles. Which ones, I don't know. But I know that lots of things that look plausible on paper don't look so good in practice. The same with synfuels. Where are they? Yes, there are startups, I know about the HN startup Prometheus. But for the time being, it's all pie in the sky. How much synfuel is being produced now? The wikipedia page [3] does not seem to be very up to date, which is a bad sign in itself, it means nothing of note has happened lately. But they quote a worldwide capacity of 240000 barrels per day. You can compare that with the crude oil production of 80 million bpd. And of course, that worldwide capacity of 240k bpd is mostly high carbon intensity. The low carbon intensity fraction of that is probably negligible. The fact that Germany used the Fischer-Tropsch process in WW2 is not that relevant. Yes, it shows the technology exists, but it doesn't show it is economical in the current market conditions. And something that's not profitable is not getting built. And once it gets built, you always need to ask yourself, how long will it take us to go from where we are to where we want to be. How long does it take you to go from 1000 bpd to 100000000 bpd? Is it years, decades, or centuries? Do we see the current growth rate to allow us to create even some optimistic predictions that we'll get to some meaningful number in a few decades? If not, then there's no reason to be optimist. [1] https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas... [2] https://www.eia.gov/tools/faqs/faq.php?id=77&t=11 https://www.eia.gov/tools/faqs/faq.php?id=77&t=11 [3] https://en.wikipedia.org/wiki/Synthetic_fuel_commercialization https://en.wikipedia.org/wiki/Synthetic_fuel_commercializati...
buryat 3y ago
use the not-needed energy on carbon capture
mpweiher 3y ago
It's not that they're too expensive to load follow, it's that it makes no sense for them to load follow. If the "backup" is reliable, inexpensive, CO2 free energy, why on earth do I need an unreliable, also CO2 free "primary" source?
doikor 3y ago
> Nuclear power plants are currently too expensive to not be used at 100% all the time (except when you need to perform maintenance). France has been load following with their nuclear plants for decades. They have to as they have so much of it. The reactors in Germany also did/do the same. The reactors in Finland also started to do that too during this summer as we are having more and more wind (and a new 1600MW nuclear reactor) and a huge chunk is sold on the spot market (so if nobody bought your nuclear power you are not allowed to send it to the grid). Basically leaving ramping down your production as the only choice.
- _ph_ 3y ago
  France has a lot of water power which helps with balancing the grid and Germany never had more than 30% of nuclear in the mix, so basically little load following was required. Also, both countries, as most industry nations, tried hard to shape the consumption to be constant over time. Like extra cheap electricity in the night which lead to heating systems which would electrically heat up over night and dispense the heat during the day. Also, the European grid helps a lot with balancing, electricity is constantly traded and exchanged between the countries.

kragen 3y ago

i agree with almost everything in your cogent and well-informed comment, with only two exceptions: - forests can only increase in biomass up to some relatively low limit; you may be correct that in the usa they currently absorb more than gas plants emit, but that is not a sustainable situation, unless you start cutting them down and sequestering the carbon - you can get pretty far covering seasonal fluctuations with simple overprovisioning also i think you're not taking into account the likely advent of mass production of synfuel

credit_guy 3y ago
> unless you start cutting them down and sequestering the carbon We actually do that all the time: we cut down trees and make houses. Here's a number from the US Forest Service [1] that as of 2009 the US was using 187 million m3 of solid wood products. > you can get pretty far covering seasonal fluctuations with simple overprovisioning Fully agree. > likely advent of mass production of synfuel I'm extremely pessimistic about that. The best hope is for hydrogen, but even that looks all but hopeless to me, if you don't count "blue hydrogen". [1] https://www.fs.usda.gov/research/treesearch/33882 https://www.fs.usda.gov/research/treesearch/33882
- kragen 3y ago
  187 million m³ of solid wood products is on the order of 187 million tonnes of carbon dioxide, which is an insignificantly small number in this context currently we need to sequester 950 gigatonnes of carbon dioxide, or about 300 gigatonnes of carbon, to get back to pre-industrial levels. this number increases by 40 gigatonnes carbon dioxide or 13 gigatonnes carbon per year https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere#Current_situation https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_at... so roughly we need to sequester 1500 times as much carbon dioxide as the us forest service number, every year. so if the usa builds enough wood housing and other buildings for 450 billion people next year, and another 450 billion people the year after that, and so on indefinitely, that would compensate for current carbon emissions but this is not a plausible plan by contrast, direct air capture followed by injection into the crust where carbonatation of olivine and similar minerals sequesters the carbon is a plausible plan, but one that will require a lot of energy why are you extremely pessimistic about mass production of synfuel? fischer-tropsch produced 25% of germany's wartime automotive fuel, though of course that was starting from coal rather than carbon dioxide: https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process#History https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces...
  - credit_guy 3y ago
    I don't think like that, and nobody thinks like that. The first target before we think about getting back to preindustrial levels, is to get to net zero by 2050. If you start measuring things against a goal that's too distant in the future, you just give up. Ok, if we talk net zero, then the what does it take the US to do that? The US is not the entire globe. Currently the US emits about 6.34 gigatons of CO2-equivalent and absorbs about 754 megatons for a net of 5.59 gigatons CO2e [1]. The emissions from natural gas power generation are at 743 megatons [2]. If we could eliminate all other emissions except for the ones from the natural gas power plants, we'd already be slightly net negative. If we could keep the existing natural gas power plants, but run them only as peaker plants, we'd be well into negative territory. You are saying that 754 megatons is not sustainable without some program of carbon sequestration. I pointed out that 14 years ago the US consumed 187 million m3 of solid wood, which is of the order of 187 megatons of CO2 sequestration. Or about 25% of the annual CO2 absorption by all the US forests and grasslands. To me that sounds like a pretty huge rotation speed, and certainly sustainable in the long run. > by contrast, direct air capture followed by injection into the crust where carbonatation of olivine and similar minerals sequesters the carbon is a plausible plan It's a plausible plan, but that's about it. The facts on the ground are that we don't do it for some reason. Most likely there are some serious obstacles. Which ones, I don't know. But I know that lots of things that look plausible on paper don't look so good in practice. The same with synfuels. Where are they? Yes, there are startups, I know about the HN startup Prometheus. But for the time being, it's all pie in the sky. How much synfuel is being produced now? The wikipedia page [3] does not seem to be very up to date, which is a bad sign in itself, it means nothing of note has happened lately. But they quote a worldwide capacity of 240000 barrels per day. You can compare that with the crude oil production of 80 million bpd. And of course, that worldwide capacity of 240k bpd is mostly high carbon intensity. The low carbon intensity fraction of that is probably negligible. The fact that Germany used the Fischer-Tropsch process in WW2 is not that relevant. Yes, it shows the technology exists, but it doesn't show it is economical in the current market conditions. And something that's not profitable is not getting built. And once it gets built, you always need to ask yourself, how long will it take us to go from where we are to where we want to be. How long does it take you to go from 1000 bpd to 100000000 bpd? Is it years, decades, or centuries? Do we see the current growth rate to allow us to create even some optimistic predictions that we'll get to some meaningful number in a few decades? If not, then there's no reason to be optimist. [1] https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas... [2] https://www.eia.gov/tools/faqs/faq.php?id=77&t=11 https://www.eia.gov/tools/faqs/faq.php?id=77&t=11 [3] https://en.wikipedia.org/wiki/Synthetic_fuel_commercialization https://en.wikipedia.org/wiki/Synthetic_fuel_commercializati...

buryat 3y ago

use the not-needed energy on carbon capture

mpweiher 3y ago

It's not that they're too expensive to load follow, it's that it makes no sense for them to load follow. If the "backup" is reliable, inexpensive, CO2 free energy, why on earth do I need an unreliable, also CO2 free "primary" source?

doikor 3y ago

> Nuclear power plants are currently too expensive to not be used at 100% all the time (except when you need to perform maintenance). France has been load following with their nuclear plants for decades. They have to as they have so much of it. The reactors in Germany also did/do the same. The reactors in Finland also started to do that too during this summer as we are having more and more wind (and a new 1600MW nuclear reactor) and a huge chunk is sold on the spot market (so if nobody bought your nuclear power you are not allowed to send it to the grid). Basically leaving ramping down your production as the only choice.

_ph_ 3y ago
France has a lot of water power which helps with balancing the grid and Germany never had more than 30% of nuclear in the mix, so basically little load following was required. Also, both countries, as most industry nations, tried hard to shape the consumption to be constant over time. Like extra cheap electricity in the night which lead to heating systems which would electrically heat up over night and dispense the heat during the day. Also, the European grid helps a lot with balancing, electricity is constantly traded and exchanged between the countries.