4 ms·

What are you going to do at night, or in Germany when it’s cloudy and rainy for a month straight? I can show you my electricity consumption from my heat pump in

What are you going to do at night, or in Germany when it’s cloudy and rainy for a month straight? I can show you my electricity consumption from my heat pump in the winter compared to the electricity my PV system produced. Hint: it doesn’t work. And batteries aren’t an option either, because I can’t generate any excess electricity during the day. Take a look at the Fraunhofer study.

pfdietz 1y ago
One complements batteries with hydrogen (burned in turbines) or long term thermal storage. Germany has plenty of salt formations for very cheap hydrogen storage, and there are no geographical constraints on thermal storage.
- looping__lui 1y ago
  Tell the Fraunhofer about that.
  - pfdietz 1y ago
    I don't need to -- we can just look in that report you linked earlier (thanks!), on pages 5 and 6. They already know. They knew five years ago.
    - looping__lui 1y ago
      Yes, they mention hydrogen caverns and thermal storage on pp. 5–6 — but those are more theoretical potentials than real, scalable solutions today. That’s why even in Fraunhofer’s own scenarios we still see 500–750 GW of wind + PV (6–9× average load) and 100–150 GW gas backup on top. In practice, it’s the massive renewable overcapacity that smooths supply, with storage playing only a limited supporting role.
      - pfdietz 1y ago
        How are they not scalable? And realize that even in the fantasy of an all-nuclear world, electrolyzers are still required: they are needed to make the hydrogen that's the feedstock for synthesis of ammonia, without which world agricultural yield would be much lower. Given that this all-nuclear world has electrolyzers, what then prevents these from being driven by renewables (perhaps buffered short term by batteries), and the hydrogen then stored (as has been done for decades in underground storage caverns, just like natural gas is stored)? And once that is done, what prevents some of that hydrogen from then being profitably used to drive turbines when electricity prices are high? Gas turbines burning hydrogen are nearly identical to ones burning natural gas (just minor differences in the combustors) and have been available industrially for decades. Using reasonable projections for cost (some of which have already been superseded by lower figures), we can estimate the cost of providing synthetic baseload from wind/solar/storage in Europe, using historical weather data. It comes in cheaper than nuclear. https://model.energy/ https://model.energy/
jopsen 1y ago
Gas? Which you then only use 5-10% of the time. At least that's what I hear people saying.
- looping__lui 1y ago
  Well, you gonna pay for building gas power plants that never run? Customers will need to pay for gas power plants that cover the entire electricity need (read up on Fraunhofer on the thinking: https://www.ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Fraunhofer-ISE-Studie-Wege-zu-einem-klimaneutralen-Energiesystem.pdf https://www.ise.fraunhofer.de/content/dam/ise/de/documents/p... ) . But that infrastructure will sit there idle most of the time. That’s not driving down electricity prices. And you’ll still end up with higher carbon emissions than France.
  - adgjlsfhk1 1y ago
    Solar panels are cheap enough that it pays to have gas plants that never run.
  - toast0 1y ago
    > Well, you gonna pay for building gas power plants that never run? Customers will need to pay for gas power plants that cover the entire electricity need Paying for the plant but not having to pay for it to run most of the time is probably cheaper than having it running most of the time. Maybe there's opportunities for net metering for customers with backup generators. At the right price per kWH, I would run my generator and feed into the grid... personally, my fuel cost is likely too high for that to make sense very often, but I think there's likely some hidden capacity there with the right incentives.
    - looping__lui 1y ago
      Take a look at this study: https://www.ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Fraunhofer-ISE-Studie-Wege-zu-einem-klimaneutralen-Energiesystem.pdf https://www.ise.fraunhofer.de/content/dam/ise/de/documents/p... Germany will require 100-150 GW capacity which cost about 1000 EUR/kW and would require an investment of 100+B EUR. Electricity prices already skyrocketed in Germany and no end in sight. Listen: I invested in PV, in low energy houses, in heat pumps - but the PV/wind strategy doesn’t work the way people would like them to in their ideology and Germany has proven that.
triceratops 1y ago
> And batteries aren’t an option either, because I can’t generate any excess electricity during the day You can't generate excess electricity because you don't have enough land or rooftop (I mean maybe you do, I'm talking about the typical homeowner). Utilities can overbuild panels because they're extremely cheap. LFP batteries have a self-discharge rate of 2-5% per month. Once they're cheap enough, over-building batteries to move summer sunshine into the winter months also becomes an option*. At $100/kwh, you could power Sweden 6 months a year for about $60bn (EDIT: $6tn, sorry) in batteries (yes labor and everything else will probably double that cost). And that doesn't even account for recent advances in sodium batteries, which reportedly bring that price down to $20/kwh * (Any battery experts know why this might be wrong? I'm using basic arithmetic, not physics. That tells me a battery charged to 100% in July or August will still have > 70% charge left in December)
- looping__lui 1y ago
  Germany would require a ballpark of 100 MILLION tons of Teslas Megapack grade batteries to run on battery for 2 weeks - which is even shorter than what we had to endure due to “Dunkelflauten”.
  - triceratops 1y ago
    Why would Germany need to run solely on battery for 2 weeks? Do you expect 2 weeks with 0 sun and wind all over continental Europe? In any case, at $100/kwh, it would cost $250bn (EDIT: $25tn sorry) in batteries and maybe the same in installation costs to power Germany for 6 months a year. At the lower $20/kwh price tag it would be more like $5tn, compared to Germany's ~$4.5tn GDP. Over 10 years it could be done. (And 6 months' storage is maybe too much anyway)
    - input_sh 1y ago
      I mean not the whole Europe and this is obviously geography-dependent, but those "dark periods" are fairly common for Germany, as in there are weeks-long periods where Germany itself produces basically no electricity from wind or solar. In the most extreme case some years back, that "dark period" lasted almost two months. This isn't to say they can't import it from elsewhere, they just can't make any of their own. Adding more capacity wouldn't do anything, it would take an incredible amount of batteries to handle the more extreme end of those "dark periods".
nicoburns 1y ago
Batteries are definitely an option for day -> night shifting. If not today, then soon, and without requiring and technological advances. Seasonal or month-long periods of low-generation are another matter, and as-yet an unsolved problem. It may be that synthesizing fuels ends up being a sensible option here.

pfdietz 1y ago

One complements batteries with hydrogen (burned in turbines) or long term thermal storage. Germany has plenty of salt formations for very cheap hydrogen storage, and there are no geographical constraints on thermal storage.

looping__lui 1y ago
Tell the Fraunhofer about that.
- pfdietz 1y ago
  I don't need to -- we can just look in that report you linked earlier (thanks!), on pages 5 and 6. They already know. They knew five years ago.
  - looping__lui 1y ago
    Yes, they mention hydrogen caverns and thermal storage on pp. 5–6 — but those are more theoretical potentials than real, scalable solutions today. That’s why even in Fraunhofer’s own scenarios we still see 500–750 GW of wind + PV (6–9× average load) and 100–150 GW gas backup on top. In practice, it’s the massive renewable overcapacity that smooths supply, with storage playing only a limited supporting role.
    - pfdietz 1y ago
      How are they not scalable? And realize that even in the fantasy of an all-nuclear world, electrolyzers are still required: they are needed to make the hydrogen that's the feedstock for synthesis of ammonia, without which world agricultural yield would be much lower. Given that this all-nuclear world has electrolyzers, what then prevents these from being driven by renewables (perhaps buffered short term by batteries), and the hydrogen then stored (as has been done for decades in underground storage caverns, just like natural gas is stored)? And once that is done, what prevents some of that hydrogen from then being profitably used to drive turbines when electricity prices are high? Gas turbines burning hydrogen are nearly identical to ones burning natural gas (just minor differences in the combustors) and have been available industrially for decades. Using reasonable projections for cost (some of which have already been superseded by lower figures), we can estimate the cost of providing synthetic baseload from wind/solar/storage in Europe, using historical weather data. It comes in cheaper than nuclear. https://model.energy/ https://model.energy/

jopsen 1y ago

Gas? Which you then only use 5-10% of the time. At least that's what I hear people saying.

looping__lui 1y ago
Well, you gonna pay for building gas power plants that never run? Customers will need to pay for gas power plants that cover the entire electricity need (read up on Fraunhofer on the thinking: https://www.ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Fraunhofer-ISE-Studie-Wege-zu-einem-klimaneutralen-Energiesystem.pdf https://www.ise.fraunhofer.de/content/dam/ise/de/documents/p... ) . But that infrastructure will sit there idle most of the time. That’s not driving down electricity prices. And you’ll still end up with higher carbon emissions than France.
- adgjlsfhk1 1y ago
  Solar panels are cheap enough that it pays to have gas plants that never run.
- toast0 1y ago
  > Well, you gonna pay for building gas power plants that never run? Customers will need to pay for gas power plants that cover the entire electricity need Paying for the plant but not having to pay for it to run most of the time is probably cheaper than having it running most of the time. Maybe there's opportunities for net metering for customers with backup generators. At the right price per kWH, I would run my generator and feed into the grid... personally, my fuel cost is likely too high for that to make sense very often, but I think there's likely some hidden capacity there with the right incentives.
  - looping__lui 1y ago
    Take a look at this study: https://www.ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Fraunhofer-ISE-Studie-Wege-zu-einem-klimaneutralen-Energiesystem.pdf https://www.ise.fraunhofer.de/content/dam/ise/de/documents/p... Germany will require 100-150 GW capacity which cost about 1000 EUR/kW and would require an investment of 100+B EUR. Electricity prices already skyrocketed in Germany and no end in sight. Listen: I invested in PV, in low energy houses, in heat pumps - but the PV/wind strategy doesn’t work the way people would like them to in their ideology and Germany has proven that.

triceratops 1y ago

> And batteries aren’t an option either, because I can’t generate any excess electricity during the day You can't generate excess electricity because you don't have enough land or rooftop (I mean maybe you do, I'm talking about the typical homeowner). Utilities can overbuild panels because they're extremely cheap. LFP batteries have a self-discharge rate of 2-5% per month. Once they're cheap enough, over-building batteries to move summer sunshine into the winter months also becomes an option*. At $100/kwh, you could power Sweden 6 months a year for about $60bn (EDIT: $6tn, sorry) in batteries (yes labor and everything else will probably double that cost). And that doesn't even account for recent advances in sodium batteries, which reportedly bring that price down to $20/kwh * (Any battery experts know why this might be wrong? I'm using basic arithmetic, not physics. That tells me a battery charged to 100% in July or August will still have > 70% charge left in December)

looping__lui 1y ago
Germany would require a ballpark of 100 MILLION tons of Teslas Megapack grade batteries to run on battery for 2 weeks - which is even shorter than what we had to endure due to “Dunkelflauten”.
- triceratops 1y ago
  Why would Germany need to run solely on battery for 2 weeks? Do you expect 2 weeks with 0 sun and wind all over continental Europe? In any case, at $100/kwh, it would cost $250bn (EDIT: $25tn sorry) in batteries and maybe the same in installation costs to power Germany for 6 months a year. At the lower $20/kwh price tag it would be more like $5tn, compared to Germany's ~$4.5tn GDP. Over 10 years it could be done. (And 6 months' storage is maybe too much anyway)
  - input_sh 1y ago
    I mean not the whole Europe and this is obviously geography-dependent, but those "dark periods" are fairly common for Germany, as in there are weeks-long periods where Germany itself produces basically no electricity from wind or solar. In the most extreme case some years back, that "dark period" lasted almost two months. This isn't to say they can't import it from elsewhere, they just can't make any of their own. Adding more capacity wouldn't do anything, it would take an incredible amount of batteries to handle the more extreme end of those "dark periods".

nicoburns 1y ago

Batteries are definitely an option for day -> night shifting. If not today, then soon, and without requiring and technological advances. Seasonal or month-long periods of low-generation are another matter, and as-yet an unsolved problem. It may be that synthesizing fuels ends up being a sensible option here.