3 ms·

I thought I'd neatly encapsulated this with the "baseload and peaking to renewables and firming" slogan but since it appears we need greater depth: Typically n

I thought I'd neatly encapsulated this with the "baseload and peaking to renewables and firming" slogan but since it appears we need greater depth: Typically nuclear/renewables is not used with storage at all, it's instead used for baseload/cheap-n-clean-load with the peaks/firming handled by other types of primary generation, traditionally natural gas or non-pumped hydro that dams a river. Nuclear can trip out in seconds or be put offline by fault investigations or fuel reloading, so you need alternative generation with enough capacity to supply the whole grid at any given time, and enough storage and or firming to be able to do this for a week or more in the event that nuclear generation is low for an extended period of time (like France the other year).

belorn 2y ago
Looking at this from a historical perspective, Nuclear with other types of primary generation did not generate a highly variable grid. Its a recent phenomena in Europe that has caused spot prices jumps from negative to 2$ per kWh, which the primary blame being put in volatile energy production. If we are claiming that nuclear is similar to renewables, we should expect regions where nuclear is being decommissioned to have an increase in renewables with no increase in natural gas consumption. This is however not the case. This has been demonstrated by the decommissions of nuclear plants in Germany and Sweden, with fossil fuel emissions being increased as a direct results. To take Sweden as an in-depth example, after the decommission of their south based nuclear power plant the two major natural gas plants in the region went from operating a few times a year to running almost 24/7, only shutting down briefly during optimal weather conditions. They are now the highest source of pollution in that region, and more natural gas plants are being planned for construction. As a result the government funding for the "reserve energy" has increased significantly (ie, fossil fuel subsidies).
- ZeroGravitas 2y ago
  Germany's gas generation has indeed been flat while nuclear and coal is being phased out, so I guess you've very strongly proved my point. https://ourworldindata.org/grapher/electricity-prod-source-stacked?time=1999..latest&country=~DEU https://ourworldindata.org/grapher/electricity-prod-source-s... I'm also not seeing your claimed Swedish impact in the data: https://ourworldindata.org/grapher/electricity-prod-source-stacked?time=1999..latest&country=SWE https://ourworldindata.org/grapher/electricity-prod-source-s... Also worth bearing in mind that support payments generally are used to keep fossil plants open because they no longer burn enough fossil fuels to earn a profit from energy sales. It's an insurance policy which needn't ever burn any fuel to be worthwhile.
  - AnthonyMouse 2y ago
    > Germany's gas generation has indeed been flat while nuclear and coal is being phased out, so I guess you've very strongly proved my point. That graph shows domestic generation falling by more than 100TWh and being replaced by "nothing" -- which is to say nothing shown on that graph, because now instead of generating and exporting electricity they're importing it: https://ourworldindata.org/grapher/net-electricity-imports?tab=chart&country=~DEU https://ourworldindata.org/grapher/net-electricity-imports?t... Primarily from France, which is using nuclear, hydro and natural gas (in that order).
    - ZeroGravitas 2y ago
      The net import in 2023 was only 10TWh so you've over explained this by x10, so something else must be going on than just importing nuclear from France (which is roughly 8TWh that year) France is the biggest single source of imports but not the majority of imports since Germany imports from a range of countries and the energy mix of imports is roughly: > the shares of RE, nuclear, and fossils in Germany net imports were 59%, 33%, and 8%, respectively. https://www.renewable-ei.org/en/activities/column/REupdate/20240719.php https://www.renewable-ei.org/en/activities/column/REupdate/2... Nice graph: https://www.renewable-ei.org/realfiles/pdfimage/1721291204_68794581.png https://www.renewable-ei.org/realfiles/pdfimage/1721291204_6... And this makes sense as imports work on the merit order effect, with the cheapest going first. Why buy fossil electricity from one neighbour if another has cheap wind available.
      - AnthonyMouse 2y ago
        > The net import in 2023 was only 10TWh so you've over explained this by x10, so something else must be going on than just importing nuclear from France (which is roughly 8TWh that year) They were previously exporting 90TWh. > the shares of RE, nuclear, and fossils in Germany net imports were 59%, 33%, and 8%, respectively. That's still a pretty big proportion of nuclear and fossil fuels, and it's not clear that the way they're calculating that actually works. Imports are going to be needed at times of high demand or low renewable output, when baseload capacity is being consumed for domestic use by the exporting country and incremental power for export has to come disproportionately from peaker plants, i.e. fossil fuels (or lower curtailment by nuclear in France). Moreover, they're counting hydro under renewable, e.g. Norway is "99% renewable" but is in fact 88% hydro.
AnthonyMouse 2y ago
> Typically nuclear/renewables is not used with storage at all, it's instead used for baseload/cheap-n-clean-load with the peaks/firming handled by other types of primary generation, traditionally natural gas or non-pumped hydro that dams a river. But we're trying to get rid of fossil fuels. If you have enough primary generation from hydro dams or something else that doesn't emit carbon to reliably handle the whole grid then that would be the entire solution by itself. There aren't enough suitable hydro sites to handle the whole grid, which means only needing half as many (or only needing enough storage to make up the difference against half as many) is quite an advantage. > Nuclear can trip out in seconds or be put offline by fault investigations or fuel reloading, so you need alternative generation with enough capacity to supply the whole grid at any given time, and enough storage and or firming to be able to do this for a week or more in the event that nuclear generation is low for an extended period of time (like France the other year). You're talking about an individual nuclear plant rather than the whole grid. One plant out of dozens or hundreds being temporarily offline is not a big deal, and refueling in particular is easy because it can be scheduled for seasons when power demand is lower. The issue with renewables is that it can be night or cloudy or still across thousands of square miles at once, and then low generation periods correlate across the whole grid instead of being isolated to an individual plant, and happen randomly based on weather rather than having any ability to be scheduled.
- ben_w 2y ago
  > The issue with renewables is that it can be night or cloudy or still across thousands of square miles at once If it was only thousands of square miles, it wouldn't be a problem at all. Whole of the UK is about 100,000 square miles, not sure how much more if you also include the offshore areas suitable for wind. Texas is about 270,000 square miles with the same caveat, and (I think) less interconnect capacity to other networks than the UK. > and happen randomly based on weather Wasn't that literally the cause of the French reactors having problems? The national weather causing a correlated output reduction in many reactors at the same time?
  - AnthonyMouse 2y ago
    > If it was only thousands of square miles, it wouldn't be a problem at all. > Whole of the UK is about 100,000 square miles, not sure how much more if you also include the offshore areas suitable for wind. > Texas is about 270,000 square miles with the same caveat It isn't "only" thousands of square miles, weather events commonly span areas the size of what you're talking about. It's obviously going to be night across the whole region at once. It's occasionally calm across the whole continental United States. Not often, but it happens. > Wasn't that literally the cause of the French reactors having problems? The national weather causing a correlated output reduction in many reactors at the same time? It was a confluence of factors, one of which was French law that prohibited power plants from putting coolant water higher than a certain temperature back into the river. When the river flow is low and the intake temperature is high, meeting the regulatory requirement necessitated reducing heat generation, i.e. power output. The same is true for any thermal power plant (e.g. coal or natural gas). This happened following a period of anti-nuclear sentiment that resulted in labor shortages in the industry, causing other reactors to concurrently be offline for maintenance for an unusually long period of time. Obviously you can make any generation system unreliable through mismanagement/government opposition. The coolant temperature limit is a design issue. There are known designs that avoid it, e.g. situate the plant on a larger river or body of water that would provide enough cooling water even on the hottest of days, or use cooling towers instead of river water. Conversely, it's not obvious how you design a wind turbine that can provide power when there's no wind.

belorn 2y ago

Looking at this from a historical perspective, Nuclear with other types of primary generation did not generate a highly variable grid. Its a recent phenomena in Europe that has caused spot prices jumps from negative to 2$ per kWh, which the primary blame being put in volatile energy production. If we are claiming that nuclear is similar to renewables, we should expect regions where nuclear is being decommissioned to have an increase in renewables with no increase in natural gas consumption. This is however not the case. This has been demonstrated by the decommissions of nuclear plants in Germany and Sweden, with fossil fuel emissions being increased as a direct results. To take Sweden as an in-depth example, after the decommission of their south based nuclear power plant the two major natural gas plants in the region went from operating a few times a year to running almost 24/7, only shutting down briefly during optimal weather conditions. They are now the highest source of pollution in that region, and more natural gas plants are being planned for construction. As a result the government funding for the "reserve energy" has increased significantly (ie, fossil fuel subsidies).

ZeroGravitas 2y ago
Germany's gas generation has indeed been flat while nuclear and coal is being phased out, so I guess you've very strongly proved my point. https://ourworldindata.org/grapher/electricity-prod-source-stacked?time=1999..latest&country=~DEU https://ourworldindata.org/grapher/electricity-prod-source-s... I'm also not seeing your claimed Swedish impact in the data: https://ourworldindata.org/grapher/electricity-prod-source-stacked?time=1999..latest&country=SWE https://ourworldindata.org/grapher/electricity-prod-source-s... Also worth bearing in mind that support payments generally are used to keep fossil plants open because they no longer burn enough fossil fuels to earn a profit from energy sales. It's an insurance policy which needn't ever burn any fuel to be worthwhile.
- AnthonyMouse 2y ago
  > Germany's gas generation has indeed been flat while nuclear and coal is being phased out, so I guess you've very strongly proved my point. That graph shows domestic generation falling by more than 100TWh and being replaced by "nothing" -- which is to say nothing shown on that graph, because now instead of generating and exporting electricity they're importing it: https://ourworldindata.org/grapher/net-electricity-imports?tab=chart&country=~DEU https://ourworldindata.org/grapher/net-electricity-imports?t... Primarily from France, which is using nuclear, hydro and natural gas (in that order).
  - ZeroGravitas 2y ago
    The net import in 2023 was only 10TWh so you've over explained this by x10, so something else must be going on than just importing nuclear from France (which is roughly 8TWh that year) France is the biggest single source of imports but not the majority of imports since Germany imports from a range of countries and the energy mix of imports is roughly: > the shares of RE, nuclear, and fossils in Germany net imports were 59%, 33%, and 8%, respectively. https://www.renewable-ei.org/en/activities/column/REupdate/20240719.php https://www.renewable-ei.org/en/activities/column/REupdate/2... Nice graph: https://www.renewable-ei.org/realfiles/pdfimage/1721291204_68794581.png https://www.renewable-ei.org/realfiles/pdfimage/1721291204_6... And this makes sense as imports work on the merit order effect, with the cheapest going first. Why buy fossil electricity from one neighbour if another has cheap wind available.
    - AnthonyMouse 2y ago
      > The net import in 2023 was only 10TWh so you've over explained this by x10, so something else must be going on than just importing nuclear from France (which is roughly 8TWh that year) They were previously exporting 90TWh. > the shares of RE, nuclear, and fossils in Germany net imports were 59%, 33%, and 8%, respectively. That's still a pretty big proportion of nuclear and fossil fuels, and it's not clear that the way they're calculating that actually works. Imports are going to be needed at times of high demand or low renewable output, when baseload capacity is being consumed for domestic use by the exporting country and incremental power for export has to come disproportionately from peaker plants, i.e. fossil fuels (or lower curtailment by nuclear in France). Moreover, they're counting hydro under renewable, e.g. Norway is "99% renewable" but is in fact 88% hydro.

AnthonyMouse 2y ago

> Typically nuclear/renewables is not used with storage at all, it's instead used for baseload/cheap-n-clean-load with the peaks/firming handled by other types of primary generation, traditionally natural gas or non-pumped hydro that dams a river. But we're trying to get rid of fossil fuels. If you have enough primary generation from hydro dams or something else that doesn't emit carbon to reliably handle the whole grid then that would be the entire solution by itself. There aren't enough suitable hydro sites to handle the whole grid, which means only needing half as many (or only needing enough storage to make up the difference against half as many) is quite an advantage. > Nuclear can trip out in seconds or be put offline by fault investigations or fuel reloading, so you need alternative generation with enough capacity to supply the whole grid at any given time, and enough storage and or firming to be able to do this for a week or more in the event that nuclear generation is low for an extended period of time (like France the other year). You're talking about an individual nuclear plant rather than the whole grid. One plant out of dozens or hundreds being temporarily offline is not a big deal, and refueling in particular is easy because it can be scheduled for seasons when power demand is lower. The issue with renewables is that it can be night or cloudy or still across thousands of square miles at once, and then low generation periods correlate across the whole grid instead of being isolated to an individual plant, and happen randomly based on weather rather than having any ability to be scheduled.

ben_w 2y ago
> The issue with renewables is that it can be night or cloudy or still across thousands of square miles at once If it was only thousands of square miles, it wouldn't be a problem at all. Whole of the UK is about 100,000 square miles, not sure how much more if you also include the offshore areas suitable for wind. Texas is about 270,000 square miles with the same caveat, and (I think) less interconnect capacity to other networks than the UK. > and happen randomly based on weather Wasn't that literally the cause of the French reactors having problems? The national weather causing a correlated output reduction in many reactors at the same time?
- AnthonyMouse 2y ago
  > If it was only thousands of square miles, it wouldn't be a problem at all. > Whole of the UK is about 100,000 square miles, not sure how much more if you also include the offshore areas suitable for wind. > Texas is about 270,000 square miles with the same caveat It isn't "only" thousands of square miles, weather events commonly span areas the size of what you're talking about. It's obviously going to be night across the whole region at once. It's occasionally calm across the whole continental United States. Not often, but it happens. > Wasn't that literally the cause of the French reactors having problems? The national weather causing a correlated output reduction in many reactors at the same time? It was a confluence of factors, one of which was French law that prohibited power plants from putting coolant water higher than a certain temperature back into the river. When the river flow is low and the intake temperature is high, meeting the regulatory requirement necessitated reducing heat generation, i.e. power output. The same is true for any thermal power plant (e.g. coal or natural gas). This happened following a period of anti-nuclear sentiment that resulted in labor shortages in the industry, causing other reactors to concurrently be offline for maintenance for an unusually long period of time. Obviously you can make any generation system unreliable through mismanagement/government opposition. The coolant temperature limit is a design issue. There are known designs that avoid it, e.g. situate the plant on a larger river or body of water that would provide enough cooling water even on the hottest of days, or use cooling towers instead of river water. Conversely, it's not obvious how you design a wind turbine that can provide power when there's no wind.