9 ms·

And this is an expected problem with renewables that can be engineered around. It's unlikely the whole world has a drought at once during a calm night, so devel

And this is an expected problem with renewables that can be engineered around. It's unlikely the whole world has a drought at once during a calm night, so developing ways to transmit power long distances will be important.

pstuart 6mo ago
Which absolutely should be done, but having energy sovereignty is never a bad thing.
izacus 6mo ago
Having a continent-wide draught (or cold winter or other weather effect) is rather common though. Just a few years back Europe had a massive issue where draught caused both drop of hydro production and cooling for French nukes, causing energy prices to spike.
- Moldoteck 6mo ago
  No. Cooling french nukes was never a problem. In that period France was net exporting 14GW. Cooling in general isn't a problem - some modulation is done just to save fish. Maybe you are confusing with 2022 when half of french fleet was shut down to check for potential pipe cracks/corrosion esp in one of their reactor designs due to poor geometry. But that's unrelated to droughts
  - psychoslave 6mo ago
    That said, cooling does have an effect on ecosystems. Not the worst energy plant impact on that regard, but still not like it's all environmental friendly. And of course, there is the what to do with the waste dilemma. And at least with current French park, there is a dependence on the rarer kind of uranium.
    - Moldoteck 6mo ago
      Waste dilemma? You either bury it (Onkalo, Cigeo, Fosmark, etc...) like any other waste that must be isolated forever (herfa neurode) or you do some recycling one way or another, or both. Impact on environment from nuclear is minimal per UNECE. And cooling impact is minimal too, esp with towers. Uranium can be sourced from a variety of countries and enriched locally. Nuclear in general needs least amount of mining and materials per kwh
  - derriz 6mo ago
    Happens regularly. Last year’s heatwave caused a bunch of reactor shutdown across Switzerland and France - https://www.euronews.com/2025/07/02/france-and-switzerland-shut-down-nuclear-power-plants-amid-scorching-heatwave https://www.euronews.com/2025/07/02/france-and-switzerland-s...
    - hunterpayne 6mo ago
      All thermal plants have this same issue, not just nuclear. And if you lose the natural gas peakers (which are also thermal and thus has this issue), you lose your baseload renewables too. Not that it matters, renewables used for baseload make more CO2 than just using FFs. Variability is a terrible quality in an energy source.
      - tialaramex 6mo ago
        Right, so rather than "We should have more thermal plants" what you want is a non-thermal electrical generator, and what do you know all the major renewable sources qualify, whether that's a wind turbine, hydro-electric or PV. Do you know what else you'd get a lot of if it's so hot in the summer that you can't use lake and river water for cooling? Sunlight to run your PV. Because that's exactly why the water was heating up.
        Moldoteck 6mo ago
        you can in fact use water for cooling. It's that sometimes you may be concerned about fish and not hurt it, esp with passthrough systems. But there are even more adv solutions (wastewater, dry cooling combo)
      - sehansen 6mo ago
        No, natural gas _peakers_ don't need water for cooling, since they don't have steam turbines like combined cycle gas plants. Cooling is only necessary in thermal plants to condense the steam on the low-pressure side of the steam turbine. And excessive stability is also a terrible quality in an energy source. The only reason we used to put up with base-load power plants was because they were cheap; if they weren't we might as well have used peaker plants all the time.
  - izacus 6mo ago
    No, I'm not - https://www.euronews.com/2025/07/02/france-and-switzerland-shut-down-nuclear-power-plants-amid-scorching-heatwave https://www.euronews.com/2025/07/02/france-and-switzerland-s... A lot of NPPs in France are cooled with river water and they need to be kept at low output if the rivers are too warm.
    - Moldoteck 6mo ago
      Are you? It impacts 0.02% of annual production and during this time EDF is net exporting 14GW. Does this sound as an issue to you?
  - mayama 6mo ago
    Problem isn't nuclear cooling per se. It's the designs of these nuclear reactors which expected to work with mild European weather. India and China have nuclear reactors working in desert without any cooling issues. Of course, as most of EU and west atrophied in building nuclear reactors in general, building new reactors or modifications won't be economical.
    - Moldoteck 6mo ago
      it's not economical because in the same period summer prices are dirt cheap. EDF is already maxing export in that period, where do you want to squeeze some extra GW? why would you?
- Tepix 6mo ago
  Cooling for French nuclear reactors, yes. More than once since 2020. But nukes?
ambicapter 6mo ago
Or just use nuclear as base load, and battery storage as much as you can.
- colechristensen 6mo ago
  You don't need battery storage if you've got hydro. You need solar. Make hydro the backup, fill reservoirs as your reserve and sell extra energy when they're nearly full.
  - tialaramex 6mo ago
    I can see this makes sense especially for medium term storage. A lot full of batteries is great for the next ten seconds, next ten minutes, even to some extent the next ten hours, but it surely doesn't make much sense to store ten days of electricity that way compared to just keeping the water behind a dam. We know that many of the world's large dams are capturing snow melt or other seasonal flows, running them only when solar or wind can't provide the power you need lets you make more effective use of the same resource.
    - colechristensen 6mo ago
      Except for very short term peaks (less than 15 minutes-ish) it doesn't make any sense at all to use hydro to charge batteries. You've got a dam, you might as well let water through later than incur the losses of a round trip to batteries and back to the grid.
    - hvb2 6mo ago
      Except that in many cases there's people living downstream doing agriculture using that water for irrigation. There's just this tiny dispute about that in the nile delta between Egypt and Ethiopia https://en.wikipedia.org/wiki/Grand_Ethiopian_Renaissance_Dam https://en.wikipedia.org/wiki/Grand_Ethiopian_Renaissance_Da...
  - znkynz 6mo ago
    There are two types of hydro - run of river, and ones with large lake storage. You need the ones with large lake storage, rather that the ones with a lake to build a head.

pstuart 6mo ago

Which absolutely should be done, but having energy sovereignty is never a bad thing.

izacus 6mo ago

Having a continent-wide draught (or cold winter or other weather effect) is rather common though. Just a few years back Europe had a massive issue where draught caused both drop of hydro production and cooling for French nukes, causing energy prices to spike.

Moldoteck 6mo ago
No. Cooling french nukes was never a problem. In that period France was net exporting 14GW. Cooling in general isn't a problem - some modulation is done just to save fish. Maybe you are confusing with 2022 when half of french fleet was shut down to check for potential pipe cracks/corrosion esp in one of their reactor designs due to poor geometry. But that's unrelated to droughts
- psychoslave 6mo ago
  That said, cooling does have an effect on ecosystems. Not the worst energy plant impact on that regard, but still not like it's all environmental friendly. And of course, there is the what to do with the waste dilemma. And at least with current French park, there is a dependence on the rarer kind of uranium.
  - Moldoteck 6mo ago
    Waste dilemma? You either bury it (Onkalo, Cigeo, Fosmark, etc...) like any other waste that must be isolated forever (herfa neurode) or you do some recycling one way or another, or both. Impact on environment from nuclear is minimal per UNECE. And cooling impact is minimal too, esp with towers. Uranium can be sourced from a variety of countries and enriched locally. Nuclear in general needs least amount of mining and materials per kwh
- derriz 6mo ago
  Happens regularly. Last year’s heatwave caused a bunch of reactor shutdown across Switzerland and France - https://www.euronews.com/2025/07/02/france-and-switzerland-shut-down-nuclear-power-plants-amid-scorching-heatwave https://www.euronews.com/2025/07/02/france-and-switzerland-s...
  - hunterpayne 6mo ago
    All thermal plants have this same issue, not just nuclear. And if you lose the natural gas peakers (which are also thermal and thus has this issue), you lose your baseload renewables too. Not that it matters, renewables used for baseload make more CO2 than just using FFs. Variability is a terrible quality in an energy source.
    - tialaramex 6mo ago
      Right, so rather than "We should have more thermal plants" what you want is a non-thermal electrical generator, and what do you know all the major renewable sources qualify, whether that's a wind turbine, hydro-electric or PV. Do you know what else you'd get a lot of if it's so hot in the summer that you can't use lake and river water for cooling? Sunlight to run your PV. Because that's exactly why the water was heating up.
      - Moldoteck 6mo ago
        you can in fact use water for cooling. It's that sometimes you may be concerned about fish and not hurt it, esp with passthrough systems. But there are even more adv solutions (wastewater, dry cooling combo)
    - sehansen 6mo ago
      No, natural gas _peakers_ don't need water for cooling, since they don't have steam turbines like combined cycle gas plants. Cooling is only necessary in thermal plants to condense the steam on the low-pressure side of the steam turbine. And excessive stability is also a terrible quality in an energy source. The only reason we used to put up with base-load power plants was because they were cheap; if they weren't we might as well have used peaker plants all the time.
- izacus 6mo ago
  No, I'm not - https://www.euronews.com/2025/07/02/france-and-switzerland-shut-down-nuclear-power-plants-amid-scorching-heatwave https://www.euronews.com/2025/07/02/france-and-switzerland-s... A lot of NPPs in France are cooled with river water and they need to be kept at low output if the rivers are too warm.
  - Moldoteck 6mo ago
    Are you? It impacts 0.02% of annual production and during this time EDF is net exporting 14GW. Does this sound as an issue to you?
- mayama 6mo ago
  Problem isn't nuclear cooling per se. It's the designs of these nuclear reactors which expected to work with mild European weather. India and China have nuclear reactors working in desert without any cooling issues. Of course, as most of EU and west atrophied in building nuclear reactors in general, building new reactors or modifications won't be economical.
  - Moldoteck 6mo ago
    it's not economical because in the same period summer prices are dirt cheap. EDF is already maxing export in that period, where do you want to squeeze some extra GW? why would you?
Tepix 6mo ago
Cooling for French nuclear reactors, yes. More than once since 2020. But nukes?

ambicapter 6mo ago

Or just use nuclear as base load, and battery storage as much as you can.

colechristensen 6mo ago
You don't need battery storage if you've got hydro. You need solar. Make hydro the backup, fill reservoirs as your reserve and sell extra energy when they're nearly full.
- tialaramex 6mo ago
  I can see this makes sense especially for medium term storage. A lot full of batteries is great for the next ten seconds, next ten minutes, even to some extent the next ten hours, but it surely doesn't make much sense to store ten days of electricity that way compared to just keeping the water behind a dam. We know that many of the world's large dams are capturing snow melt or other seasonal flows, running them only when solar or wind can't provide the power you need lets you make more effective use of the same resource.
  - colechristensen 6mo ago
    Except for very short term peaks (less than 15 minutes-ish) it doesn't make any sense at all to use hydro to charge batteries. You've got a dam, you might as well let water through later than incur the losses of a round trip to batteries and back to the grid.
  - hvb2 6mo ago
    Except that in many cases there's people living downstream doing agriculture using that water for irrigation. There's just this tiny dispute about that in the nile delta between Egypt and Ethiopia https://en.wikipedia.org/wiki/Grand_Ethiopian_Renaissance_Dam https://en.wikipedia.org/wiki/Grand_Ethiopian_Renaissance_Da...
- znkynz 6mo ago
  There are two types of hydro - run of river, and ones with large lake storage. You need the ones with large lake storage, rather that the ones with a lake to build a head.