4 ms·

how much storage capacity do you think is needed to deal with the worst cases for solar/wind that are encountered during the year? Last time I did a rough calcu

how much storage capacity do you think is needed to deal with the worst cases for solar/wind that are encountered during the year? Last time I did a rough calculation on this, I quickly realized there is a fairly low upper limit on how much wind/solar capacity one can install, because the storage required is so immense.

mbgerring 4y ago
Don’t have the number in my head, but my day job is building software to enable (among other things) moving load around to avoid the “worst case,” which is just as good as building the storage.
- ftth_finland 4y ago
  > Don’t have the number in my head That’s because it’s weeks, if not months, in places that have actual seasons. > moving load around to avoid the “worst case,” There is no such thing with base load in winter. You either provide constant heating or people freeze. There are places where rearranging the chairs works and there are places where it doesn’t.
  - sveme 4y ago
    There hasn‘t been a single day in Germany last year where renewable energy dropped below 30% of consumption. So overbuilt geographically dispersed systems can handle a very wide range of weather conditions, even without battery and hydrogen storage taken into account.
    - kgabis 4y ago
      German grid must be very low in terms of CO2 emissions then, right? Not just marginally better than neighbouring Poland?
ZeroGravitas 4y ago
One of the biggest blind spots in this conversation is people who think renewables need lots of storage, but nuclear doesn't. What's your calculation on the amount of batteries needed for a nuclear grid to meet all peak needs? Once you've done the sums you'll almost certainly say something like, "well we can just overbuild nuclear and find uses for the excess, including timeshifting". It's the exact same problem (matching demand and supply), with the same solutions but one gets hyperfocus at the same time the other is totally ignored.
- ExoticPearTree 4y ago
  Nuclear doesn't need any storage because the power is generated continuously at the same pace. On the other hand, there's no sun during the night and wind strength is variable and cannot always be harnessed. If you want to have all the power generated by renewable, you would need big enough storage to hold all the power consumption during the highest peaks - like really hot summer nights where everyone is running AC at maximum. And it tends to cost quite a lot to have a giant UPS. And, because we need power 24/7, you need to have that in a redundant fashion, which basically boils down to two giant UPS systems in the gigawatt range. And I have this feeling that doing this is very dirty and very expensive to build and maintain.
  - HDThoreaun 4y ago
    Demand isn't flat and nuclear can't scale quickly enough to meet the daily peaks and troughs.
    - illiarian 4y ago
      > Demand isn't flat and nuclear can't scale quickly enough to meet the daily peaks and troughs. Of course it can. https://www.oecd-nea.org/upload/docs/application/pdf/2021-12/technical_and_economic_aspects_of_load_following_with_nuclear_power_plants.pdf https://www.oecd-nea.org/upload/docs/application/pdf/2021-12... --- start quote --- Modern nuclear plans with light water reactors are designed to have strong manoeuvring capabilities. Nuclear power plants in France and in Germany operate in load-following mode, i.e. they participate in the primary and secondary frequency control, and some units follow a variable load programme with one or two large power changes per day. ... according to the current version of the European Utilities Requirements (EUR) the NPP must at least be capable of daily load cycling operation between 50% and 100 % of its rated power P. with a rate of change of electric output of 3-5% of P, per minute. Most of the modern designs implement even higher manoeuvrability capabilities, with the possibility of planned and unplanned load-following in a wide power range and with ramps of 5% P, per minute. (Where P is rated power) --- end quote ---

mbgerring 4y ago

Don’t have the number in my head, but my day job is building software to enable (among other things) moving load around to avoid the “worst case,” which is just as good as building the storage.

ftth_finland 4y ago
> Don’t have the number in my head That’s because it’s weeks, if not months, in places that have actual seasons. > moving load around to avoid the “worst case,” There is no such thing with base load in winter. You either provide constant heating or people freeze. There are places where rearranging the chairs works and there are places where it doesn’t.
- sveme 4y ago
  There hasn‘t been a single day in Germany last year where renewable energy dropped below 30% of consumption. So overbuilt geographically dispersed systems can handle a very wide range of weather conditions, even without battery and hydrogen storage taken into account.
  - kgabis 4y ago
    German grid must be very low in terms of CO2 emissions then, right? Not just marginally better than neighbouring Poland?

ZeroGravitas 4y ago

One of the biggest blind spots in this conversation is people who think renewables need lots of storage, but nuclear doesn't. What's your calculation on the amount of batteries needed for a nuclear grid to meet all peak needs? Once you've done the sums you'll almost certainly say something like, "well we can just overbuild nuclear and find uses for the excess, including timeshifting". It's the exact same problem (matching demand and supply), with the same solutions but one gets hyperfocus at the same time the other is totally ignored.

ExoticPearTree 4y ago
Nuclear doesn't need any storage because the power is generated continuously at the same pace. On the other hand, there's no sun during the night and wind strength is variable and cannot always be harnessed. If you want to have all the power generated by renewable, you would need big enough storage to hold all the power consumption during the highest peaks - like really hot summer nights where everyone is running AC at maximum. And it tends to cost quite a lot to have a giant UPS. And, because we need power 24/7, you need to have that in a redundant fashion, which basically boils down to two giant UPS systems in the gigawatt range. And I have this feeling that doing this is very dirty and very expensive to build and maintain.
- HDThoreaun 4y ago
  Demand isn't flat and nuclear can't scale quickly enough to meet the daily peaks and troughs.
  - illiarian 4y ago
    > Demand isn't flat and nuclear can't scale quickly enough to meet the daily peaks and troughs. Of course it can. https://www.oecd-nea.org/upload/docs/application/pdf/2021-12/technical_and_economic_aspects_of_load_following_with_nuclear_power_plants.pdf https://www.oecd-nea.org/upload/docs/application/pdf/2021-12... --- start quote --- Modern nuclear plans with light water reactors are designed to have strong manoeuvring capabilities. Nuclear power plants in France and in Germany operate in load-following mode, i.e. they participate in the primary and secondary frequency control, and some units follow a variable load programme with one or two large power changes per day. ... according to the current version of the European Utilities Requirements (EUR) the NPP must at least be capable of daily load cycling operation between 50% and 100 % of its rated power P. with a rate of change of electric output of 3-5% of P, per minute. Most of the modern designs implement even higher manoeuvrability capabilities, with the possibility of planned and unplanned load-following in a wide power range and with ramps of 5% P, per minute. (Where P is rated power) --- end quote ---