3 ms·

Your personal impression doesn't really matter though. What matters is the statistics. Of course there is sun in Germany. Yes, there's less. But then it's also

by audunw 3y ago

Your personal impression doesn't really matter though. What matters is the statistics. Of course there is sun in Germany. Yes, there's less. But then it's also cooler which makes the solar panels more efficient. What matters is if it's economical to use solar panels there, which it is. In summer, where some areas will use quite a bit of AC, there's more daylight hours than regions further south. In winter, if you have vertically mounted panels, a nice effect you can get is that the snow reflects extra sunlight from the ground to the solar panel. Fun fact, even the airport in Longyearbyen in Svalbard, Norway - an island close to the north pole - has solar panels. They're mounted vertically on the walls, since the sun is never very high in the sky. There's no sun at all in winter, but in summer there's sun 24/7. https://sunpower.maxeon.com/int/case-study/energy-arctic-circle-moving-coal-solar https://sunpower.maxeon.com/int/case-study/energy-arctic-cir... It's surprising how much production they get even that far north: "the PV system produces as much as 70 percent of what is typically produced in Germany" So please don't use your subjective impression about how bright you feel it is to gauge the viability of solar. I can tell you from personal experience, it's not very bright in Svalbard even in summer. BTW, much of the energy need in winter in northern climates is for heating. It's surprisingly effective to store thermal energy over several months. So it's actually viable to dump heat from excess solar in a thermal reservoir in summer, and use that heat in winter.

rolisz 3y ago
> It's surprisingly effective to store thermal energy over several months. Do tell more.
- nimeni 3y ago
  For example, this project [1] in Finland will provide 200 MW of district heating and can store 90 GWh. Cost estimate was 109M EUR in 2021 [2]. [1]: https://www.vantaanenergia.fi/en/we/carbon-negativity-2030/heatstorage/ https://www.vantaanenergia.fi/en/we/carbon-negativity-2030/h... [2]: https://tem.fi/paatos?decisionId=0900908f8077a0e8 https://tem.fi/paatos?decisionId=0900908f8077a0e8
  - rolisz 3y ago
    Interesting. We'll see in 2026 when it's finished how much it actually costs and how well it actually works :)
  - AnonymousPlanet 3y ago
    Cool, so you would only need about 120 of those to compensate Germany's current wind and solar power in the gaps without wind and sun. That's just 1.3 billion Euros. That's better than the last time I checked out heat storage. Then it was 100MWh for roughly a football stadium sized area with subterranean sand.
AnonymousPlanet 3y ago
> It's surprisingly effective to store thermal energy over several months. And how much would you need? Have you done the maths on this? I did. There are plenty of times in e.g. November when neither wind nor solar are good for much (production drops to like 1-2% of the average). That goes on for weeks. Just trying to compensate those losses for two weeks for the current amount of wind and solar Germany has, takes > 10 TWh of storage. How much thermal storage do you think would we need to build to get that? I made those calculations to get an idea how much storage we would need to be able to finally shut down power stations running on coal or gas. I was quite shocked about the number. Whenever someone points out the realities of things some people are quick to counter with some utopian ideas, but usually they don't do the math on it. I encourage you to always make a calculation, at least on a napkin, to get an idea of the magnitude of what would be required. Your comment reads like it would be as easy as the flick of a wrist because something "is surprisingly effective". It's not. It takes the amount of many, many Stuttgart 21s in dedication, costs and time.
- mschuster91 3y ago
  > There are plenty of times in e.g. November when neither wind nor solar are good for much (production drops to like 1-2% of the average). That goes on for weeks. So what. Either overbuild solar and wind to a degree that even with reduced generation capacity needs can still be met and use the over-generation in summer to produce hydrogen, e-fuels for air and maritime or whatever, or run the capacity of the storage until it's depleted and use gas peakers for the 2-4 weeks in the year where nothing else can fill the demand.
  - cbmuser 3y ago
    Overbuilding doesn’t help when there is zero wind or solar generation. Wind is usually tied across the continent and low wind in Germany usually conincides with low wind in the rest of Europe.
  - AnonymousPlanet 3y ago
    Please have a thorough look at https://www.smard.de https://www.smard.de and download their data to do some statistics on it. This should give you an impression of what, when and how long is missing. Hint: It's not just two to three weeks per year. There are many such gaps. And they're not just a couple of days long. All your ideas hinge on storage that somehow magically comes to existence. I told you the numbers and you then argue with science fiction. No one knows how to build a reliable hydrogen network of the size that would be necessary. The efficiencies for generation are abysmal, especially if you try to generate just from water and electricity and not from natural gas. I don't believe you even remotely grasp the magnitude of the challenges ahead. Again, I would like to encourage the use of real data and math. Less science fiction and wishful thinking.
cbmuser 3y ago
Germany had to return 19 coal-fired power plants with a total capacity of 7.3 GW to the electricity market simply because neither wind nor solar provide dispatchable power and hence can never replace conventional power plants. They just help saving fuel. https://www.smard.de/home/rueckkehr-von-kohlekraftwerken-an-den-strommarkt-209208 https://www.smard.de/home/rueckkehr-von-kohlekraftwerken-an-...
- olddustytrail 3y ago
  No, they brought them in because of the issue of gas supplies after Russia invaded Ukraine. Didn't you hear about this? It was in the news...
- Marvin_Martian 3y ago
  Germany was facing the cutoff from russian gas, which had provided more than half of its gas imports, and was also in the process of shutting down its last nuclear reactors. To suggest that the return of those coal power plants was due to renewables underdelivering, seems to be misleading at best. Personally, that whole fiasco served as a reminder of the dangers of fossil fuel imports from undemocratic states.
  - nixass 3y ago
    > To suggest that the return of those coal power plants was due to renewables underdelivering, seems to be misleading at best If that money was invested into nuclear power plants and not into failed Energirwende then there would be no need for that and no fear of Russian cut offs

by audunw 3y ago

rolisz 3y ago

> It's surprisingly effective to store thermal energy over several months. Do tell more.

nimeni 3y ago
For example, this project [1] in Finland will provide 200 MW of district heating and can store 90 GWh. Cost estimate was 109M EUR in 2021 [2]. [1]: https://www.vantaanenergia.fi/en/we/carbon-negativity-2030/heatstorage/ https://www.vantaanenergia.fi/en/we/carbon-negativity-2030/h... [2]: https://tem.fi/paatos?decisionId=0900908f8077a0e8 https://tem.fi/paatos?decisionId=0900908f8077a0e8
- rolisz 3y ago
  Interesting. We'll see in 2026 when it's finished how much it actually costs and how well it actually works :)
- AnonymousPlanet 3y ago
  Cool, so you would only need about 120 of those to compensate Germany's current wind and solar power in the gaps without wind and sun. That's just 1.3 billion Euros. That's better than the last time I checked out heat storage. Then it was 100MWh for roughly a football stadium sized area with subterranean sand.

AnonymousPlanet 3y ago

> It's surprisingly effective to store thermal energy over several months. And how much would you need? Have you done the maths on this? I did. There are plenty of times in e.g. November when neither wind nor solar are good for much (production drops to like 1-2% of the average). That goes on for weeks. Just trying to compensate those losses for two weeks for the current amount of wind and solar Germany has, takes > 10 TWh of storage. How much thermal storage do you think would we need to build to get that? I made those calculations to get an idea how much storage we would need to be able to finally shut down power stations running on coal or gas. I was quite shocked about the number. Whenever someone points out the realities of things some people are quick to counter with some utopian ideas, but usually they don't do the math on it. I encourage you to always make a calculation, at least on a napkin, to get an idea of the magnitude of what would be required. Your comment reads like it would be as easy as the flick of a wrist because something "is surprisingly effective". It's not. It takes the amount of many, many Stuttgart 21s in dedication, costs and time.

mschuster91 3y ago
> There are plenty of times in e.g. November when neither wind nor solar are good for much (production drops to like 1-2% of the average). That goes on for weeks. So what. Either overbuild solar and wind to a degree that even with reduced generation capacity needs can still be met and use the over-generation in summer to produce hydrogen, e-fuels for air and maritime or whatever, or run the capacity of the storage until it's depleted and use gas peakers for the 2-4 weeks in the year where nothing else can fill the demand.
- cbmuser 3y ago
  Overbuilding doesn’t help when there is zero wind or solar generation. Wind is usually tied across the continent and low wind in Germany usually conincides with low wind in the rest of Europe.
- AnonymousPlanet 3y ago
  Please have a thorough look at https://www.smard.de https://www.smard.de and download their data to do some statistics on it. This should give you an impression of what, when and how long is missing. Hint: It's not just two to three weeks per year. There are many such gaps. And they're not just a couple of days long. All your ideas hinge on storage that somehow magically comes to existence. I told you the numbers and you then argue with science fiction. No one knows how to build a reliable hydrogen network of the size that would be necessary. The efficiencies for generation are abysmal, especially if you try to generate just from water and electricity and not from natural gas. I don't believe you even remotely grasp the magnitude of the challenges ahead. Again, I would like to encourage the use of real data and math. Less science fiction and wishful thinking.

cbmuser 3y ago

Germany had to return 19 coal-fired power plants with a total capacity of 7.3 GW to the electricity market simply because neither wind nor solar provide dispatchable power and hence can never replace conventional power plants. They just help saving fuel. https://www.smard.de/home/rueckkehr-von-kohlekraftwerken-an-den-strommarkt-209208 https://www.smard.de/home/rueckkehr-von-kohlekraftwerken-an-...

olddustytrail 3y ago
No, they brought them in because of the issue of gas supplies after Russia invaded Ukraine. Didn't you hear about this? It was in the news...
Marvin_Martian 3y ago
Germany was facing the cutoff from russian gas, which had provided more than half of its gas imports, and was also in the process of shutting down its last nuclear reactors. To suggest that the return of those coal power plants was due to renewables underdelivering, seems to be misleading at best. Personally, that whole fiasco served as a reminder of the dangers of fossil fuel imports from undemocratic states.
- nixass 3y ago
  > To suggest that the return of those coal power plants was due to renewables underdelivering, seems to be misleading at best If that money was invested into nuclear power plants and not into failed Energirwende then there would be no need for that and no fear of Russian cut offs