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How are solar and wind not sustainable or efficient? We've just recently hit the 20% mark here in the US. I'm all for a smart blend of nuclear/wind/solar/etc

How are solar and wind not sustainable or efficient? We've just recently hit the 20% mark here in the US. I'm all for a smart blend of nuclear/wind/solar/etc to achieve clean energy https://electrek.co/2022/05/10/us-hits-a-record-20-of-electricity-from-wind-and-solar-in-april/ https://electrek.co/2022/05/10/us-hits-a-record-20-of-electr...

TheBlight 4y ago
How does solar work in the winter in northern latitudes?
- totalview 4y ago
  Alaskan here; it doesn’t work so hot in the winter months. Even if they are kept clear by maintenance workers (not that hard or expensive to hire someone to clear snow from a panel) the sun’s azimuth is so low in the winter that there is hardly any energy produced.
  - fluoridation 4y ago
    Small correction: you mean altitude, not azimuth. Altitude is how far you need to tilt your head vertically to look at an object. Azimuth is the compass direction.
- edent 4y ago
  Pretty good. You can download several years of data from my domestic panels at https://shkspr.mobi/blog/2020/07/1800-days-of-minute-by-minute-solar-generation-data/ https://shkspr.mobi/blog/2020/07/1800-days-of-minute-by-minu... Sure, some days they'll be covered by snow. But in industrial systems that can easily be melted / brushed off. Obviously they don't generate as much in winter as in summer. But cool bright winter days are surprisingly plentiful.
- Analemma_ 4y ago
  Very well. Rooftop solar in Seattle pays for itself in 7-9 years, and we have the least sunlight and cheapest grid power of almost any place in the continental US.
  - TedDoesntTalk 4y ago
    > Rooftop solar in Seattle pays for itself in 7-9 years Can you show me the arithmetic for that? I understand rooftop solar to cost $20,000 - $25,000. Is your non-solar electric bill over 7-9 years really more expensive than that? Seems impossible.
    - marssaxman 4y ago
      I'm afraid I don't have the exact numbers anymore, but I determined that the 2700W solar panel array installed on my Seattle house for about $14k in 2013 (including a new breaker panel) had paid for itself before the end of 2019. The system worked really well. People often think that solar won't work well in Seattle because it's cloudy so often, but light still comes in through the overcast, and solar panels don't care which angle the photons hit them from. Meanwhile, lower ambient temperatures mean the panels work more efficiently.
      - seanmcdirmid 4y ago
        Solar won’t work on new townhomes in Seattle with rooftop decks (since we don’t have to worry about snow so much?). There is simply no place to put them unless you give up your deck.
        marssaxman 4y ago
        Alas, indeed. I'd have installed solar panels on the townhouse I bought in 2020 if there were anywhere to put them, but there would only be room for 800 watts, at most - not really worth it.
    - jamie_ca 4y ago
      Victoria BC area here (practically next door), it wouldn't work for us. My annual hydro bill was $2400 in 2018 with baseboard heating, and $2050 for 16,500kWh in 2021 after we put in a heat pump. 3 bedroom detached. A recent article suggested a typical 4 kW system around here would cost $10k for 3261 kWh a year, or about $405 in credit at a blended rate. Another suggests an 11 kW system at $27,500, which could maybe hit 9000 kWh - about $1100 in credit. We do have net metering with BC Hydro so it'll just wash through, but that's still a 25 year payback horizon.
- CyanBird 4y ago
  Most of the planet is not "winter in northern latitudes" Indeed, most of the world is rather sunny and "not" located in "northern latitudes"
  - throwaway5752 4y ago
    Most of the planet, most of the people are not in the Arctic. Brief search indicates 4 million, globally. You could have people in the Arctic powering their homes with peat or lignite and it wouldn't be a huge problem. Happily NG is better for this, and the rest of the world has fewer problems with solar seasonality.
arcticbull 4y ago
They're not efficient at turning sunlight into power - somewhere around 20% depending on the technology, which continues to improve albeit slowly. This efficiency goes down about 2.5% in the first year and another [edit](0.5%-1%) in each subsequent year [1]. These numbers are all at 25C, which is significantly lower than a black solar panel is going to be out in the sun - which reduces its efficiency a further 10-25%. [2] So typical 20% efficiency solar panel at 45C in year 2 is already starting at 17.5% efficiency, and by year 10 is down to just [edit](15%) efficiency. And then while lower temperatures do improve efficiency, they tend to happen in higher latitudes which get less sunlight to begin with. 60% of Ontario's power (about half of Canada by population) comes from just 3 nuclear plants (Bruce, Darlington and Pickering). Replacing them with solar panels would cover an area the size of the entire greater Toronto area in silicon and plastic, give or take. [3] And it would need to be replaced every 20 years. Solar and wind play a role, but nuclear does too. Edit: Corrected degradation amount per dpierce9 [1] https://energyeducation.ca/encyclopedia/Solar_cell_efficiency https://energyeducation.ca/encyclopedia/Solar_cell_efficienc... [2] https://www.cleanenergyreviews.info/blog/most-efficient-solar-panels https://www.cleanenergyreviews.info/blog/most-efficient-sola... [3] https://www.cer-rec.gc.ca/en/data-analysis/energy-markets/provincial-territorial-energy-profiles/provincial-territorial-energy-profiles-ontario.html https://www.cer-rec.gc.ca/en/data-analysis/energy-markets/pr...
- dpierce9 4y ago
  This is some bad reasoning. Solar efficiency is very different from say engine efficiency. A very efficient combustion engine is 35% efficient meaning it wastes 65% of the energy in the input fuel. Solar panels don’t waste sunlight and have no input costs. Rooftop solar turns 20% of something that would have been 100% wasted into high grade energy. A very efficient coal power plant is 45% efficient before transmission losses. That means more than half the energy in the coal is wasted. Solar wastes nothing. Your numbers on solar panel degradation are also incorrect based on my experience in the industry. They do degrade but not at that at 7+% per year for ten years. Edit: corrected degradation amount
  - arcticbull 4y ago

TheBlight 4y ago

How does solar work in the winter in northern latitudes?

totalview 4y ago
Alaskan here; it doesn’t work so hot in the winter months. Even if they are kept clear by maintenance workers (not that hard or expensive to hire someone to clear snow from a panel) the sun’s azimuth is so low in the winter that there is hardly any energy produced.
- fluoridation 4y ago
  Small correction: you mean altitude, not azimuth. Altitude is how far you need to tilt your head vertically to look at an object. Azimuth is the compass direction.
edent 4y ago
Pretty good. You can download several years of data from my domestic panels at https://shkspr.mobi/blog/2020/07/1800-days-of-minute-by-minute-solar-generation-data/ https://shkspr.mobi/blog/2020/07/1800-days-of-minute-by-minu... Sure, some days they'll be covered by snow. But in industrial systems that can easily be melted / brushed off. Obviously they don't generate as much in winter as in summer. But cool bright winter days are surprisingly plentiful.
Analemma_ 4y ago
Very well. Rooftop solar in Seattle pays for itself in 7-9 years, and we have the least sunlight and cheapest grid power of almost any place in the continental US.
- TedDoesntTalk 4y ago
  > Rooftop solar in Seattle pays for itself in 7-9 years Can you show me the arithmetic for that? I understand rooftop solar to cost $20,000 - $25,000. Is your non-solar electric bill over 7-9 years really more expensive than that? Seems impossible.
  - marssaxman 4y ago
    I'm afraid I don't have the exact numbers anymore, but I determined that the 2700W solar panel array installed on my Seattle house for about $14k in 2013 (including a new breaker panel) had paid for itself before the end of 2019. The system worked really well. People often think that solar won't work well in Seattle because it's cloudy so often, but light still comes in through the overcast, and solar panels don't care which angle the photons hit them from. Meanwhile, lower ambient temperatures mean the panels work more efficiently.
    - seanmcdirmid 4y ago
      Solar won’t work on new townhomes in Seattle with rooftop decks (since we don’t have to worry about snow so much?). There is simply no place to put them unless you give up your deck.
      - marssaxman 4y ago
        Alas, indeed. I'd have installed solar panels on the townhouse I bought in 2020 if there were anywhere to put them, but there would only be room for 800 watts, at most - not really worth it.
  - jamie_ca 4y ago
    Victoria BC area here (practically next door), it wouldn't work for us. My annual hydro bill was $2400 in 2018 with baseboard heating, and $2050 for 16,500kWh in 2021 after we put in a heat pump. 3 bedroom detached. A recent article suggested a typical 4 kW system around here would cost $10k for 3261 kWh a year, or about $405 in credit at a blended rate. Another suggests an 11 kW system at $27,500, which could maybe hit 9000 kWh - about $1100 in credit. We do have net metering with BC Hydro so it'll just wash through, but that's still a 25 year payback horizon.
CyanBird 4y ago
Most of the planet is not "winter in northern latitudes" Indeed, most of the world is rather sunny and "not" located in "northern latitudes"
- throwaway5752 4y ago
  Most of the planet, most of the people are not in the Arctic. Brief search indicates 4 million, globally. You could have people in the Arctic powering their homes with peat or lignite and it wouldn't be a huge problem. Happily NG is better for this, and the rest of the world has fewer problems with solar seasonality.

arcticbull 4y ago

They're not efficient at turning sunlight into power - somewhere around 20% depending on the technology, which continues to improve albeit slowly. This efficiency goes down about 2.5% in the first year and another [edit](0.5%-1%) in each subsequent year [1]. These numbers are all at 25C, which is significantly lower than a black solar panel is going to be out in the sun - which reduces its efficiency a further 10-25%. [2] So typical 20% efficiency solar panel at 45C in year 2 is already starting at 17.5% efficiency, and by year 10 is down to just [edit](15%) efficiency. And then while lower temperatures do improve efficiency, they tend to happen in higher latitudes which get less sunlight to begin with. 60% of Ontario's power (about half of Canada by population) comes from just 3 nuclear plants (Bruce, Darlington and Pickering). Replacing them with solar panels would cover an area the size of the entire greater Toronto area in silicon and plastic, give or take. [3] And it would need to be replaced every 20 years. Solar and wind play a role, but nuclear does too. Edit: Corrected degradation amount per dpierce9 [1] https://energyeducation.ca/encyclopedia/Solar_cell_efficiency https://energyeducation.ca/encyclopedia/Solar_cell_efficienc... [2] https://www.cleanenergyreviews.info/blog/most-efficient-solar-panels https://www.cleanenergyreviews.info/blog/most-efficient-sola... [3] https://www.cer-rec.gc.ca/en/data-analysis/energy-markets/provincial-territorial-energy-profiles/provincial-territorial-energy-profiles-ontario.html https://www.cer-rec.gc.ca/en/data-analysis/energy-markets/pr...

dpierce9 4y ago
This is some bad reasoning. Solar efficiency is very different from say engine efficiency. A very efficient combustion engine is 35% efficient meaning it wastes 65% of the energy in the input fuel. Solar panels don’t waste sunlight and have no input costs. Rooftop solar turns 20% of something that would have been 100% wasted into high grade energy. A very efficient coal power plant is 45% efficient before transmission losses. That means more than half the energy in the coal is wasted. Solar wastes nothing. Your numbers on solar panel degradation are also incorrect based on my experience in the industry. They do degrade but not at that at 7+% per year for ten years. Edit: corrected degradation amount
- arcticbull 4y ago