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With solar and batteries getting cheaper and cheaper, is this still a topic? Or at least for the time being until that "cheaper" gets cheaper enough?

by soco 1mo ago

petcat 1mo ago
> In March 2025, the US Department of Energy (DoE) announced US $900 million in grants to support the deployment of SMRs. One year later, the European Commission said it would invest up to €200 million (US $228 million) in the construction of SMRs. Yes, it does seem to still be a topic.
- jauntywundrkind 1mo ago
  And the US is spending vastly more to make sure renewables and solar don't get built. https://www.washingtonpost.com/business/2026/08/27/how-wind-projects-got-replaced-by-900-million-payday-trump-donors-firm/ https://www.washingtonpost.com/business/2026/08/27/how-wind-...
  - pfdietz 1mo ago
    > making sure If this is the goal, they're failing spectacularly.
RivieraKid 1mo ago
Solar + battery is very land inefficient, that's basically the main argument. Edit: Per ChatGPT's calculation, nuclear is significantly cheaper than solar + battery in my country (Czech Republic) if we're talking about adding new reactors to existing power plants.
- actionfromafar 1mo ago
  But batteries can be very distributed and stabilize and prop up the grid in ways a huge plant can't without building out distribution. (Situation dependent of course.)
- pfdietz 1mo ago
  Land is cheap. Even in Europe, the cost of land onto which renewables are put is small compared to the cost of the renewable energy equipment itself. Here in the US, it's common for the land to be just a few percent of the project cost.
deleted 1mo ago
[deleted]
fasterik 1mo ago
The problem with 100% solar+batteries is that you need to massively overbuild for the system to meet demand. It's far more cost-effective to have some portion of generation come from a firm, weather-independent source. The main options are fossil fuels, hydro, geothermal, and nuclear. Since fossil fuels emit carbon and hydro and geothermal are geographically limited, nuclear is the best option in a lot of places.
- bryanlarsen 1mo ago
  > firm That's the opposite of what you want. You want something that is cost-effective to operate at a 10%, 1% or 0.1% duty cycle. Like nat gas or hydro. Not nuclear. And overbuilding isn't the only lever you have to ensure coverage meets your target 99.99% level -- geographic diversity works really well (the wind is always blowing somewhere), and wind power production is usually negatively correlated with solar power production.
  - fasterik 1mo ago
    Natural gas and hydro are firm power. You're correct that nuclear is not a good backup power source, but that's not the suggestion. The question is whether adding high-capacity-factor firm generation reduces total system cost. In regions where hydro and geothermal are unavailable, nuclear is the next best low-carbon option. I think you're underestimating the costs and difficulties associated with 100% renewables, especially transmission capacity between regions.
    - bryanlarsen 1mo ago
      I think you're underestimating the costs and difficulties associated with 99.99% renewables and/or using it as a straw man against the highly inexpensive and achievable 95% renewables. You're also underestimating the costs of using nuclear to achieve 99.99% reliability on top of a grid with 95% renewables: in that scenario you need nuclear capable of supplying ~100% of your power. In which case you might as well ditch the renewables. But the world does not have the quadrillions needed to go 100% nuclear. The world does have the 10s of trillions needed to go 95-99% renewable.
inglor_cz 1mo ago
Scaling is a problem. How many batteries do you need to power, say, entire Scandinavia during winter? That would be a lot of lithium, btw. "Dunkelflaute" periods when it is dark and no wind to run the wind turbines are common in northern winters, IIRC the longest one a few years ago was 12 days long. Which means that in order to have a reasonable buffer against it, you would need enough batteries to supply the entire region for three weeks. Not going to happen, unless we discover some much more efficient class of batteries.
- bryanlarsen 1mo ago
  That 12 day event was a regional event in Germany, there was still lots of wind in the North Sea. And sun & wind didn't drop to 0, it dropped below 10%. Dunkelflaute's are a German phenomenon: the standard pattern in most of the world is that the high pressure systems that suppress winds are generally sunny. And the high elevation areas in Germany are sunny during a dunkelflaute. IOW, batteries aren't the only answer required to cover a dunkelflaute.
  - pfdietz 1mo ago
    Hydrogen is one possibility for a 100% grid to cover Dunkelflauten and seasonal leveling (the former for wind, the latter for solar). To see the effects on overall cost per MWh, explore at https://model.energy/ https://model.energy/
- dalyons 1mo ago
  boy am i tired of hearing that Dunkelflaute word as if its some kind of gotcha. Even ignoring the fact that you can continue to source power from other geographies during a localized phenomenon..... Just burn gas in peaker plants for the few days a year that this happens. That small amount of emissions wont matter for the next 50 years of decarbonization, after which we'll likely have plenty of other options. The absolutism in all these arguments is so tiring, as if its not 100% perfect solution for 100% of every imaginable scenario than its no good. 95% reduction over a year would be astounding, we would have won the climate battle.
istjohn 1mo ago
It is if the nuclear industry pays for it to be. See the disclaimer at the bottom of the article.

With solar and batteries getting cheaper and cheaper, is this still a topic? Or at least for the time being until that "cheaper" gets cheaper enough?

by soco 1mo ago

With solar and batteries getting cheaper and cheaper, is this still a topic? Or at least for the time being until that "cheaper" gets cheaper enough?

petcat 1mo ago

> In March 2025, the US Department of Energy (DoE) announced US $900 million in grants to support the deployment of SMRs. One year later, the European Commission said it would invest up to €200 million (US $228 million) in the construction of SMRs. Yes, it does seem to still be a topic.

jauntywundrkind 1mo ago
And the US is spending vastly more to make sure renewables and solar don't get built. https://www.washingtonpost.com/business/2026/08/27/how-wind-projects-got-replaced-by-900-million-payday-trump-donors-firm/ https://www.washingtonpost.com/business/2026/08/27/how-wind-...
- pfdietz 1mo ago
  > making sure If this is the goal, they're failing spectacularly.

RivieraKid 1mo ago

Solar + battery is very land inefficient, that's basically the main argument. Edit: Per ChatGPT's calculation, nuclear is significantly cheaper than solar + battery in my country (Czech Republic) if we're talking about adding new reactors to existing power plants.

actionfromafar 1mo ago
But batteries can be very distributed and stabilize and prop up the grid in ways a huge plant can't without building out distribution. (Situation dependent of course.)
pfdietz 1mo ago
Land is cheap. Even in Europe, the cost of land onto which renewables are put is small compared to the cost of the renewable energy equipment itself. Here in the US, it's common for the land to be just a few percent of the project cost.

deleted 1mo ago

[deleted]

fasterik 1mo ago

The problem with 100% solar+batteries is that you need to massively overbuild for the system to meet demand. It's far more cost-effective to have some portion of generation come from a firm, weather-independent source. The main options are fossil fuels, hydro, geothermal, and nuclear. Since fossil fuels emit carbon and hydro and geothermal are geographically limited, nuclear is the best option in a lot of places.

bryanlarsen 1mo ago
> firm That's the opposite of what you want. You want something that is cost-effective to operate at a 10%, 1% or 0.1% duty cycle. Like nat gas or hydro. Not nuclear. And overbuilding isn't the only lever you have to ensure coverage meets your target 99.99% level -- geographic diversity works really well (the wind is always blowing somewhere), and wind power production is usually negatively correlated with solar power production.
- fasterik 1mo ago
  Natural gas and hydro are firm power. You're correct that nuclear is not a good backup power source, but that's not the suggestion. The question is whether adding high-capacity-factor firm generation reduces total system cost. In regions where hydro and geothermal are unavailable, nuclear is the next best low-carbon option. I think you're underestimating the costs and difficulties associated with 100% renewables, especially transmission capacity between regions.
  - bryanlarsen 1mo ago
    I think you're underestimating the costs and difficulties associated with 99.99% renewables and/or using it as a straw man against the highly inexpensive and achievable 95% renewables. You're also underestimating the costs of using nuclear to achieve 99.99% reliability on top of a grid with 95% renewables: in that scenario you need nuclear capable of supplying ~100% of your power. In which case you might as well ditch the renewables. But the world does not have the quadrillions needed to go 100% nuclear. The world does have the 10s of trillions needed to go 95-99% renewable.

inglor_cz 1mo ago

Scaling is a problem. How many batteries do you need to power, say, entire Scandinavia during winter? That would be a lot of lithium, btw. "Dunkelflaute" periods when it is dark and no wind to run the wind turbines are common in northern winters, IIRC the longest one a few years ago was 12 days long. Which means that in order to have a reasonable buffer against it, you would need enough batteries to supply the entire region for three weeks. Not going to happen, unless we discover some much more efficient class of batteries.

bryanlarsen 1mo ago
That 12 day event was a regional event in Germany, there was still lots of wind in the North Sea. And sun & wind didn't drop to 0, it dropped below 10%. Dunkelflaute's are a German phenomenon: the standard pattern in most of the world is that the high pressure systems that suppress winds are generally sunny. And the high elevation areas in Germany are sunny during a dunkelflaute. IOW, batteries aren't the only answer required to cover a dunkelflaute.
- pfdietz 1mo ago
  Hydrogen is one possibility for a 100% grid to cover Dunkelflauten and seasonal leveling (the former for wind, the latter for solar). To see the effects on overall cost per MWh, explore at https://model.energy/ https://model.energy/
dalyons 1mo ago
boy am i tired of hearing that Dunkelflaute word as if its some kind of gotcha. Even ignoring the fact that you can continue to source power from other geographies during a localized phenomenon..... Just burn gas in peaker plants for the few days a year that this happens. That small amount of emissions wont matter for the next 50 years of decarbonization, after which we'll likely have plenty of other options. The absolutism in all these arguments is so tiring, as if its not 100% perfect solution for 100% of every imaginable scenario than its no good. 95% reduction over a year would be astounding, we would have won the climate battle.

istjohn 1mo ago

It is if the nuclear industry pays for it to be. See the disclaimer at the bottom of the article.