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Comparing installed capacity between power plants is misleading. Since you can't control solar output, in practice solar will have 3-10x less than the install

by Kuinox 3y ago

Comparing installed capacity between power plants is misleading. Since you can't control solar output, in practice solar will have 3-10x less than the installed capacity.

Retric 3y ago
Capacity factor adjusts for that. Some solar farms are over 31% where nuclear caps at ~92% so it’s more like 2.5 - 3.5 rather than 3-10x. Nuclear goes as low as 67%, and some peaking power plants are under 5%. But that’s due to demand rather than the inability to generate power.
- Kuinox 3y ago
  Nuclear power factor is often lowered in Europe to not waste solar/wind energy. The commenter I was replying to mentioned installed capacity, which is misleading.
  - Retric 3y ago
    Nuclear’s biggest issue is the demand curve. France was getting ~68-72% before wind and solar was a thing because the demand was just that low on nights and weekends even with significant exports. Which is why most countries that under 30% of total electricity, but renewables are likely to push this even lower even if you prioritize nuclear over renewables simply due to differences in cost.
    - shagie 3y ago
      You can see an example of this with Germany and a comparison of 2012 and 2020 - https://upload.wikimedia.org/wikipedia/commons/a/a8/Renewables_need_flexible_backup_not_baseload.png https://upload.wikimedia.org/wikipedia/commons/a/a8/Renewabl... In 2012, nuclear was a fairly consistent... eyeballing it at 10% of the load. With 2020 there's no nuclear and pumped storage becomes the flexible load while solar has a much larger portion of the total load. If 2020 had the base load generation from nuclear, that sunny Sunday would have caused some problems. And an old article about wind and hydro and managing that energy balance on the Columbia River - https://www.forbes.com/sites/jonbruner/2011/10/20/the-high-stakes-math-behind-the-wests-greatest-river/?sh=13563084222b https://www.forbes.com/sites/jonbruner/2011/10/20/the-high-s... > The enormous supply of hydroelectricity during spring runoff can push electricity prices to zero—the BPA gives away electricity to local utilities for free when it’s forced to produce more than it wants to. Since wind producers enjoy production subsidies, they can push rates below zero, effectively paying other utilities to switch off their generators. Last winter, the BPA told wind producers under its balancing authority that it wouldn’t pay negative rates to them during high-water events. (In this example, they could put more water over the spillway to reduce the power generation so that wind wouldn't have to idle... but that would have meant mixing more air in the water and that can suffocate the fish and impact the salmon fishery in Oregon - https://www.oregon.gov/deq/wq/tmdls/pages/tmdls-columbia-river.aspx https://www.oregon.gov/deq/wq/tmdls/pages/tmdls-columbia-riv... and https://apps.ecology.wa.gov/publications/documents/0203004.pdf https://apps.ecology.wa.gov/publications/documents/0203004.p... pages 13-15)
    - Kuinox 3y ago
      A plant following the demand curve is called a load-following power plant, and France's NPP are quite good at it, but most recent EU NPP should be able to do it. > According to the current version of the European Utility Requirements (EUR) the NPP must be capable of a minimum daily load cycling operation between 50% and 100% P r, with a rate of change of electric output of 3-5% P r /minute. https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-load-following-e.pdf https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-lo... > France in particular has a long history of utilizing aggressive load following with their PWRs [...] These reactors have the capability to regularly vary their output between 30–100% of rated power https://en.wikipedia.org/wiki/Load-following_power_plant#Nuclear_power_plants https://en.wikipedia.org/wiki/Load-following_power_plant#Nuc...
      - Retric 3y ago
        Load following Nuclear costs more per kWh because you’re getting less energy when the capacity factor drops and as is often said fuel isn’t the largest cost for nuclear. So you still need to pay just as much for for salaries, maintenance, construction, decommissioning etc when output is 10% or 100%. But you also need a more complex design with higher inherent costs.
        Kuinox 3y ago
        If you switch off the solar panels instead, it will be the solar panels that costs more.
        Retric 3y ago
        It’s a percentage increase so the vastly lower price per kWh of solar remains. Which is why everyone wants to use Solar to charge batteries, but nobody suggests that for nuclear even though it has similar issues just at different times of the day. Also, when given the option your better off reducing nuclear as it does have fuel costs.
shagie 3y ago
The value you're after for this is known as "capacity factor" - https://en.wikipedia.org/wiki/Capacity_factor https://en.wikipedia.org/wiki/Capacity_factor > The net capacity factor is the unitless ratio of actual electrical energy output over a given period of time to the theoretical maximum electrical energy output over that period. For the US for the data from 2018 (what's in Wikipedia) Nuclear 92% Conv. Hydro 42% Wind 37% Solar PV 26% Solar CSP 23% Landfill Gas 73% Other biomass 49% Geothermal 77% Coal 54% Nat Gas CC 57% Nat Gas CT 11% Nat Gas ST 13% Petrol ST 13% Petrol CT 2%

by Kuinox 3y ago

Comparing installed capacity between power plants is misleading. Since you can't control solar output, in practice solar will have 3-10x less than the installed capacity.

Retric 3y ago

Capacity factor adjusts for that. Some solar farms are over 31% where nuclear caps at ~92% so it’s more like 2.5 - 3.5 rather than 3-10x. Nuclear goes as low as 67%, and some peaking power plants are under 5%. But that’s due to demand rather than the inability to generate power.

Kuinox 3y ago
Nuclear power factor is often lowered in Europe to not waste solar/wind energy. The commenter I was replying to mentioned installed capacity, which is misleading.
- Retric 3y ago
  Nuclear’s biggest issue is the demand curve. France was getting ~68-72% before wind and solar was a thing because the demand was just that low on nights and weekends even with significant exports. Which is why most countries that under 30% of total electricity, but renewables are likely to push this even lower even if you prioritize nuclear over renewables simply due to differences in cost.
  - shagie 3y ago
    You can see an example of this with Germany and a comparison of 2012 and 2020 - https://upload.wikimedia.org/wikipedia/commons/a/a8/Renewables_need_flexible_backup_not_baseload.png https://upload.wikimedia.org/wikipedia/commons/a/a8/Renewabl... In 2012, nuclear was a fairly consistent... eyeballing it at 10% of the load. With 2020 there's no nuclear and pumped storage becomes the flexible load while solar has a much larger portion of the total load. If 2020 had the base load generation from nuclear, that sunny Sunday would have caused some problems. And an old article about wind and hydro and managing that energy balance on the Columbia River - https://www.forbes.com/sites/jonbruner/2011/10/20/the-high-stakes-math-behind-the-wests-greatest-river/?sh=13563084222b https://www.forbes.com/sites/jonbruner/2011/10/20/the-high-s... > The enormous supply of hydroelectricity during spring runoff can push electricity prices to zero—the BPA gives away electricity to local utilities for free when it’s forced to produce more than it wants to. Since wind producers enjoy production subsidies, they can push rates below zero, effectively paying other utilities to switch off their generators. Last winter, the BPA told wind producers under its balancing authority that it wouldn’t pay negative rates to them during high-water events. (In this example, they could put more water over the spillway to reduce the power generation so that wind wouldn't have to idle... but that would have meant mixing more air in the water and that can suffocate the fish and impact the salmon fishery in Oregon - https://www.oregon.gov/deq/wq/tmdls/pages/tmdls-columbia-river.aspx https://www.oregon.gov/deq/wq/tmdls/pages/tmdls-columbia-riv... and https://apps.ecology.wa.gov/publications/documents/0203004.pdf https://apps.ecology.wa.gov/publications/documents/0203004.p... pages 13-15)
  - Kuinox 3y ago
    A plant following the demand curve is called a load-following power plant, and France's NPP are quite good at it, but most recent EU NPP should be able to do it. > According to the current version of the European Utility Requirements (EUR) the NPP must be capable of a minimum daily load cycling operation between 50% and 100% P r, with a rate of change of electric output of 3-5% P r /minute. https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-load-following-e.pdf https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-lo... > France in particular has a long history of utilizing aggressive load following with their PWRs [...] These reactors have the capability to regularly vary their output between 30–100% of rated power https://en.wikipedia.org/wiki/Load-following_power_plant#Nuclear_power_plants https://en.wikipedia.org/wiki/Load-following_power_plant#Nuc...
    - Retric 3y ago
      Load following Nuclear costs more per kWh because you’re getting less energy when the capacity factor drops and as is often said fuel isn’t the largest cost for nuclear. So you still need to pay just as much for for salaries, maintenance, construction, decommissioning etc when output is 10% or 100%. But you also need a more complex design with higher inherent costs.
      - Kuinox 3y ago
        If you switch off the solar panels instead, it will be the solar panels that costs more.
        Retric 3y ago
        It’s a percentage increase so the vastly lower price per kWh of solar remains. Which is why everyone wants to use Solar to charge batteries, but nobody suggests that for nuclear even though it has similar issues just at different times of the day. Also, when given the option your better off reducing nuclear as it does have fuel costs.

shagie 3y ago

The value you're after for this is known as "capacity factor" - https://en.wikipedia.org/wiki/Capacity_factor https://en.wikipedia.org/wiki/Capacity_factor > The net capacity factor is the unitless ratio of actual electrical energy output over a given period of time to the theoretical maximum electrical energy output over that period. For the US for the data from 2018 (what's in Wikipedia) Nuclear 92% Conv. Hydro 42% Wind 37% Solar PV 26% Solar CSP 23% Landfill Gas 73% Other biomass 49% Geothermal 77% Coal 54% Nat Gas CC 57% Nat Gas CT 11% Nat Gas ST 13% Petrol ST 13% Petrol CT 2%