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Balcony solar panels isn't necessarily a bad outcome. It's enormously more resilient to natural disasters and warfare than centralized power stations, it's pot

by kragen 1y ago

Balcony solar panels isn't necessarily a bad outcome. It's enormously more resilient to natural disasters and warfare than centralized power stations, it's potentially more responsive to individual power needs than an electric regulator, and it may not even be inefficient—while solar panels in a utility-scale solar farm will have a higher capacity factor than balcony solar panels, that only saves you money on solar panels, but requires transmission, distribution, metering, and utility-scale storage capacity between the solar farm and the apartment, all of which are costly. At some price point, putting up a solar panel costs less than running a power line to your house. With "mainstream" solar panels costing €0.100 per peak watt as of August (according to https://www.solarserver.de/photovoltaik-preis-pv-modul-preisindex/ https://www.solarserver.de/photovoltaik-preis-pv-modul-preis...) it's getting harder and harder to justify the efficiencies of centralization. That is, maybe with single-axis trackers and optimal angle, your solar farm gets a capacity factor of 15% (I think Germany's average for utility-scale solar is 10%) so an average 500-watt load requires 3300 peak watts of utility-scale generation (€330), plus 3000 additional watts of inverter capacity, 2000 additional watts of storage capacity, 1000 additional watts of transmission capacity over something like 100km, and 1000 additional watts of distribution capacity. Maybe your capacity factor on the balcony is only 7.5%, so you have to spend €660 for 6600 peak watts, and you probably still need some storage capacity, so maybe you end up spending €1000, €670 more than the solar-farm panels. Maybe you need to spend €80 on a 12-volt car inverter, too. It's very easy for the cost of utility-scale inverters, transmission capacity, etc., to exceed the €750 savings you get in this case from centralization. Also, note that about 20% of the energy produced in utility-scale generation is lost in power conversion, transmission, etc. Note that I'm only talking about costs here, and only about the essential costs that come from the form of production. I'm not talking about prices, which may incorporate subsidies, permitting costs, taxes such as tariffs, transaction costs, lawsuits against non-performing building contractors, and market inefficiencies such as homeowners not having access to the zero-marginal-cost excess power that can be produced on sunny days for regulatory reasons.

hedora 1y ago
People are still paying $10K’s for rooftop solar in the 10KW range in the US. The numbers you quote suggest there’s going to be a black market for diy house-scale solar soon.
- kragen 1y ago
  I'm imagining autonomous intercontinental narcosubs full of solar panels navigating upriver and mooring under trees on a rainy night, met by hard-boiled crews of heavily tattooed solar panel installers with gold teeth toting AK-47s, who load the illicit panels into a beer delivery truck.
AnthonyMouse 1y ago
> it's getting harder and harder to justify the efficiencies of centralization. A lot of times they aren't even real to begin with. People assume that economies of scale keep going up as long as scale keeps going up, but that's almost never true. They typically have diminishing returns or thresholds past which the unit cost stops going down. If you want to build solar panels you have to build a factory. If the factory can produce a million solar panels a year and you only want 10 solar panels you still have to build the entire factory. It's more efficient to build a million than 10. But if people want a billion solar panels a year then you need a thousand factories, and one bigger factory isn't materially different than having two factories across the street from each other, so there's no real advantage to having them all operated by the same entity. Moreover, even if you only need 10 solar panels, you can get them from any of the thousand factories that each make a million a year. You're not losing the economies of scale by having many sellers and many buyers. Meanwhile centralization often incurs additional costs. You already identified several, but another big one is land. Individual homeowners each have a roof or balcony wall that was otherwise going to have nothing on it. A centralized solar farm is more often going to have to pay for space. Centralization is usually pushed by someone trying to monopolize something.
- kragen 1y ago
  Well, there really are economies of scale involved in building solar farms. Accidental deaths per installed megawatt are orders of magnitude lower than rooftop solar. A single-axis solar tracker can rotate hundreds of square meters of solar panels. Washing dust off solar panels can increase their output by several percent, but is much more likely to happen if it's somebody's full-time job instead of a household chore, especially a household chore that puts you at risk of falling off a roof and dying. A FLIR image can identify failing solar cells so you can queue them for replacement or repair, and a lawsuit against a maker of faulty solar panels is much more feasible if the potential damages are €60 million rather than €600. Etc. Also, clouds are less of a problem for a transmission grid with distributed solar farms than for an individual household with its own autarkic solar power system. Even for solar energy, land is not a big cost, financially speaking. Morally and environmentally, it may be (it's arguable—solar farms don't have to devastate the ecosystem the way strip mining and oil spills do), but not financially.
fweimer 1y ago
The installations discussed in the article switch off power generation if mains power goes away, both for technical and safety reasons. If you want mains-independent power, more devices are needed, which seems to cost about as much as a typical balcony solar panel installation (which is still needed, of course). I doubt many German deployments are like that, so it doesn't really improve resiliency of electrical power.

by kragen 1y ago

hedora 1y ago

People are still paying $10K’s for rooftop solar in the 10KW range in the US. The numbers you quote suggest there’s going to be a black market for diy house-scale solar soon.

kragen 1y ago
I'm imagining autonomous intercontinental narcosubs full of solar panels navigating upriver and mooring under trees on a rainy night, met by hard-boiled crews of heavily tattooed solar panel installers with gold teeth toting AK-47s, who load the illicit panels into a beer delivery truck.

AnthonyMouse 1y ago

> it's getting harder and harder to justify the efficiencies of centralization. A lot of times they aren't even real to begin with. People assume that economies of scale keep going up as long as scale keeps going up, but that's almost never true. They typically have diminishing returns or thresholds past which the unit cost stops going down. If you want to build solar panels you have to build a factory. If the factory can produce a million solar panels a year and you only want 10 solar panels you still have to build the entire factory. It's more efficient to build a million than 10. But if people want a billion solar panels a year then you need a thousand factories, and one bigger factory isn't materially different than having two factories across the street from each other, so there's no real advantage to having them all operated by the same entity. Moreover, even if you only need 10 solar panels, you can get them from any of the thousand factories that each make a million a year. You're not losing the economies of scale by having many sellers and many buyers. Meanwhile centralization often incurs additional costs. You already identified several, but another big one is land. Individual homeowners each have a roof or balcony wall that was otherwise going to have nothing on it. A centralized solar farm is more often going to have to pay for space. Centralization is usually pushed by someone trying to monopolize something.

kragen 1y ago
Well, there really are economies of scale involved in building solar farms. Accidental deaths per installed megawatt are orders of magnitude lower than rooftop solar. A single-axis solar tracker can rotate hundreds of square meters of solar panels. Washing dust off solar panels can increase their output by several percent, but is much more likely to happen if it's somebody's full-time job instead of a household chore, especially a household chore that puts you at risk of falling off a roof and dying. A FLIR image can identify failing solar cells so you can queue them for replacement or repair, and a lawsuit against a maker of faulty solar panels is much more feasible if the potential damages are €60 million rather than €600. Etc. Also, clouds are less of a problem for a transmission grid with distributed solar farms than for an individual household with its own autarkic solar power system. Even for solar energy, land is not a big cost, financially speaking. Morally and environmentally, it may be (it's arguable—solar farms don't have to devastate the ecosystem the way strip mining and oil spills do), but not financially.

fweimer 1y ago

The installations discussed in the article switch off power generation if mains power goes away, both for technical and safety reasons. If you want mains-independent power, more devices are needed, which seems to cost about as much as a typical balcony solar panel installation (which is still needed, of course). I doubt many German deployments are like that, so it doesn't really improve resiliency of electrical power.