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Paying contractors to climb on rooftops one at a time and cable up a million distinct houses is clearly not comparable to an industrial installation. Similarly

Paying contractors to climb on rooftops one at a time and cable up a million distinct houses is clearly not comparable to an industrial installation. Similarly the generation from a balcony on a bad angle, and from walking around Germany, typically shaded, makes no sense.

GaggiX 1y ago
You are completely ignoring the biggest cost: land. In a dense country like Germany, using millions of existing, "free" rooftops is vastly more efficient and economical than buying and dedicating scarce, expensive land for an industrial-scale farm. Also rooftop solar generates power at the point of consumption. This significantly reduces the need for new, expensive high-voltage transmission lines.
- plantain 1y ago
  A hectare of land is a few hundred euros per year to rent - https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Agricultural_land_prices_and_rents_-_statistics https://ec.europa.eu/eurostat/statistics-explained/index.php... Power consumption in the EU has flatlined and is even falling. New HV transmission lines are not needed - put the solar farms next to some of the shut down nuclear plants (as we now do with big batteries in Australia and decrepit coal plants).
  - GaggiX 1y ago
    >A hectare of land is a few hundred euros per year to rent Acquiring land-use rights, permitting, environmental reviews, and zoning changes for an industrial power plant costs far more than the raw rent. >Power consumption in the EU has flatlined This is dangerously short-sighted, the mass adoption of electric vehicles and heat pumps will place enormous new demands on the grid. > put the solar farms next to some of the shut down nuclear plants Solar is much more land demanding than what the decommissioned sites of nuclear power plants can offer.
    - plantain 1y ago
      >Acquiring land-use rights, permitting, environmental reviews, and zoning changes for an industrial power plant costs far more than the raw rent. So the argument against my claim that the government and market has failed if balcony solar is cost effective, is that the government is the problem?
      - GaggiX 1y ago
        This isn't a government failure. The government is correctly pricing the true cost of industrial land use: the loss of farmland and natural space. Rooftop solar is cost-effective because it cleverly avoids that cost by using land that's already developed. It's not winning because of bureaucracy, but because it's using a limited resource in a smarter way.
  - kragen 1y ago
    For context, a hectare (10000 m²) directly facing the sun receives 10 megawatts of sunlight at 1kW/m². The city of Kiel is at 54°19' north, so at the equinox a hectare near it receives about cos(54°19') ≈ 58% of that: 5.8 megawatts. If you were to cover the whole field with horizontal solar panels with a mainstream 22% efficiency, the peak electrical power generated that day would be 1.28 megawatts. But you'd need 2.20 peak megawatts of solar modules to do it, because the modules are rated based on directly facing the sun and getting 1kW/m² of sunlight, which they could never do in this situation. According to the prices on https://www.solarserver.de/photovoltaik-preis-pv-modul-preisindex/ https://www.solarserver.de/photovoltaik-preis-pv-modul-preis... those modules are currently 0.100€/Wp, so that's 280 kiloeuros of solar panels. This is about an order of magnitude more expensive than the land under them. The average produced would only be on the order of 100–200kW, because Germany's capacity factor is for shit. Kiel is in an especially terrible place, with only about 2.7kWh/m² per day on average, according to https://solargis.com/resources/free-maps-and-gis-data?locality=germany https://solargis.com/resources/free-maps-and-gis-data?locali.... In real life people tilt the panels in a solar farm toward the sun and leave space between rows of panels so they don't shade each other even in the winter. That is because, even at today's historically record low prices, the panels cost enormously more than the land they're sitting on, so it makes sense to economize a bit on panels even at the cost of needing more land.
- kragen 1y ago
  No, land is not a significant cost, not even in Germany. You're in completely the wrong order of magnitude.
  - slow_typist 1y ago
    You don’t want PV to crowd out local food production though, land is generally overused in Germany and the pressure is rising.
    - kragen 1y ago
      That could start happening if Germany's electrical energy consumption were to grow 100× or so, yeah. That might sound like I'm being sarcastic, but no, cheaper forms of energy tend to lead to more energy usage, and solar energy is cheaper, so we might see a lot more energy usage. But we're talking about problems we'll have in 20 years after we've solved global warming.
      - slow_typist 1y ago
        It happens already. Lease for green land (probably wrong terminus) and arable land went up by more than 30% in ten years [1]. PV is arguably a very small factor of influence yet. But the pressure is real. [1] https://www.bmel-statistik.de/landwirtschaft/landwirtschaftliche-betriebe/pachtpreise-und-kaufwerte https://www.bmel-statistik.de/landwirtschaft/landwirtschaftl...
        kragen 1y ago
        That page doesn't say anything about PV. https://www.ise.fraunhofer.de/content/dam/ise/en/documents/publications/studies/recent-facts-about-photovoltaics-in-germany.pdf https://www.ise.fraunhofer.de/content/dam/ise/en/documents/p... says that 17 million hectares are used for agriculture in Germany, 48000 hectares are used for golf courses, and (as of 02021) 32000 hectares were used for photovoltaics, which would be 0.2% of the agricultural area. I'm having a hard time finding current figures, but I doubt photovoltaics are more than 2% of the agricultural area yet. I don't think that's why land prices have risen 30%.
cycomanic 1y ago
So by bringing up shading and suboptimal angle you're already admitting that for an unshaded balcony these things make sense? The overhead of hanging one of these over the rail of your balcony is pretty minimal, compared to industrial scale installations. There is plenty of overhead with finance, management, billing, land use, and utility profits. That's why it makes sense.

GaggiX 1y ago

You are completely ignoring the biggest cost: land. In a dense country like Germany, using millions of existing, "free" rooftops is vastly more efficient and economical than buying and dedicating scarce, expensive land for an industrial-scale farm. Also rooftop solar generates power at the point of consumption. This significantly reduces the need for new, expensive high-voltage transmission lines.

plantain 1y ago
A hectare of land is a few hundred euros per year to rent - https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Agricultural_land_prices_and_rents_-_statistics https://ec.europa.eu/eurostat/statistics-explained/index.php... Power consumption in the EU has flatlined and is even falling. New HV transmission lines are not needed - put the solar farms next to some of the shut down nuclear plants (as we now do with big batteries in Australia and decrepit coal plants).
- GaggiX 1y ago
  >A hectare of land is a few hundred euros per year to rent Acquiring land-use rights, permitting, environmental reviews, and zoning changes for an industrial power plant costs far more than the raw rent. >Power consumption in the EU has flatlined This is dangerously short-sighted, the mass adoption of electric vehicles and heat pumps will place enormous new demands on the grid. > put the solar farms next to some of the shut down nuclear plants Solar is much more land demanding than what the decommissioned sites of nuclear power plants can offer.
  - plantain 1y ago
    >Acquiring land-use rights, permitting, environmental reviews, and zoning changes for an industrial power plant costs far more than the raw rent. So the argument against my claim that the government and market has failed if balcony solar is cost effective, is that the government is the problem?
    - GaggiX 1y ago
      This isn't a government failure. The government is correctly pricing the true cost of industrial land use: the loss of farmland and natural space. Rooftop solar is cost-effective because it cleverly avoids that cost by using land that's already developed. It's not winning because of bureaucracy, but because it's using a limited resource in a smarter way.
- kragen 1y ago
  For context, a hectare (10000 m²) directly facing the sun receives 10 megawatts of sunlight at 1kW/m². The city of Kiel is at 54°19' north, so at the equinox a hectare near it receives about cos(54°19') ≈ 58% of that: 5.8 megawatts. If you were to cover the whole field with horizontal solar panels with a mainstream 22% efficiency, the peak electrical power generated that day would be 1.28 megawatts. But you'd need 2.20 peak megawatts of solar modules to do it, because the modules are rated based on directly facing the sun and getting 1kW/m² of sunlight, which they could never do in this situation. According to the prices on https://www.solarserver.de/photovoltaik-preis-pv-modul-preisindex/ https://www.solarserver.de/photovoltaik-preis-pv-modul-preis... those modules are currently 0.100€/Wp, so that's 280 kiloeuros of solar panels. This is about an order of magnitude more expensive than the land under them. The average produced would only be on the order of 100–200kW, because Germany's capacity factor is for shit. Kiel is in an especially terrible place, with only about 2.7kWh/m² per day on average, according to https://solargis.com/resources/free-maps-and-gis-data?locality=germany https://solargis.com/resources/free-maps-and-gis-data?locali.... In real life people tilt the panels in a solar farm toward the sun and leave space between rows of panels so they don't shade each other even in the winter. That is because, even at today's historically record low prices, the panels cost enormously more than the land they're sitting on, so it makes sense to economize a bit on panels even at the cost of needing more land.
kragen 1y ago
No, land is not a significant cost, not even in Germany. You're in completely the wrong order of magnitude.
- slow_typist 1y ago
  You don’t want PV to crowd out local food production though, land is generally overused in Germany and the pressure is rising.
  - kragen 1y ago
    That could start happening if Germany's electrical energy consumption were to grow 100× or so, yeah. That might sound like I'm being sarcastic, but no, cheaper forms of energy tend to lead to more energy usage, and solar energy is cheaper, so we might see a lot more energy usage. But we're talking about problems we'll have in 20 years after we've solved global warming.
    - slow_typist 1y ago
      It happens already. Lease for green land (probably wrong terminus) and arable land went up by more than 30% in ten years [1]. PV is arguably a very small factor of influence yet. But the pressure is real. [1] https://www.bmel-statistik.de/landwirtschaft/landwirtschaftliche-betriebe/pachtpreise-und-kaufwerte https://www.bmel-statistik.de/landwirtschaft/landwirtschaftl...
      - kragen 1y ago
        That page doesn't say anything about PV. https://www.ise.fraunhofer.de/content/dam/ise/en/documents/publications/studies/recent-facts-about-photovoltaics-in-germany.pdf https://www.ise.fraunhofer.de/content/dam/ise/en/documents/p... says that 17 million hectares are used for agriculture in Germany, 48000 hectares are used for golf courses, and (as of 02021) 32000 hectares were used for photovoltaics, which would be 0.2% of the agricultural area. I'm having a hard time finding current figures, but I doubt photovoltaics are more than 2% of the agricultural area yet. I don't think that's why land prices have risen 30%.

cycomanic 1y ago

So by bringing up shading and suboptimal angle you're already admitting that for an unshaded balcony these things make sense? The overhead of hanging one of these over the rail of your balcony is pretty minimal, compared to industrial scale installations. There is plenty of overhead with finance, management, billing, land use, and utility profits. That's why it makes sense.