7 ms·

I don't get why we (Germany) don't support PV on roofs much more than we do right now.

ncmncm 4y ago
It costs more to put them on residential roofs. It is cheap on industrial and warehouse roofs, and extends the life of the roof. But they coexist well with pasture and crop land uses, too, as well as reservoirs and canals. So space for solar is absolutely abundant everywhere.
- DoingIsLearning 4y ago
  > It costs more to put them on residential roofs. If you mean slanted shingle roofs the installation is still trivial. There are also plenty of flat residential roofs which are exactly the same as an 'industrial' roof.
  - jasonwatkinspdx 4y ago
    No, what the comment says above is correct: there's a rather dramatic difference in levelized costs between utility scale solar and rooftop residential solar. Commercial rooftop solar is only slightly better than residential. There's multiple factors that feed into this, such as how much supporting infrastructure is amortized vs scale, being able to design the array for optimal lighting vs working with an existing building, systematic regular cleaning to keep the array working near peak efficiency... lots and lots more details like that. This isn't to say residential rooftop solar is bad. However atm it's something of a vanity project for people who can afford the investment. It is most definitely not some sort of obvious solves the whole problem slam dunk idiots in government are ignoring because they're stupid. They know what they're doing and are focusing on the highest impact places to put funds, and that can scale up a lot faster than fighting NIMBYs. And yeah, I'm really disappointed in Elon's solar roof tile stunt surrounding this.
    - ZeroGravitas 4y ago
      Requiring solar on new builds is a good policy though and is implemented in various German locations.
      - ncmncm 4y ago
        True, retrofitting will always cost more than outfitting during original construction, and having the builder involved enables economy of scale when many (near-)copies of the same house design are built.
    - kergonath 4y ago
      > It is most definitely not some sort of obvious solves the whole problem slam dunk idiots in government are ignoring because they're stupid. The thing is, there is no slam dunk obvious solution. But every bit that helps could be part of a more global solution that has a chance of working. Public transport, better insulation, electric transportation, solar panels and wind turbines where it makes sense, large-scale carbon-free baseline production, etc. We need to do all of that. > And yeah, I'm really disappointed in Elon's solar roof tile stunt surrounding this. Elon is not on the right side of this. His pseudo-ecologist speeches are just window dressing.
  - ncmncm 4y ago
    At issue is that a residential roof is no bigger than the residence. That does not make residential installations a dumb idea. They just cost more than alternatives. On very large commercial buildings, a project may claim economies of scale, and support dedicated personnel to keep them operating well. That said, roofs are far from the best place to site solar.
lbriner 4y ago
I suspect that the elephant in the room is simply money. Who pays? I would be happy for the government to pay me to save on my electricity bills by installing PV on my roof but I suspect they might not be so keen on the idea. Loans instead? Maybe, but there are all kinds of issues around what happens if you need to sell the property etc. Same with industrial units. You could have an enormous room that would cost £500K to install PV onto which would be way too much money for most building owners unless the feed-in tariff would cover the cost quickly but why should it? The Energy companies don't want to pay for a feed they might not need at any particularly time of day. Australia had big problems with over-supply of solar at certain times and I believe the rate went negative to try and stop people feeding it in. For me, solar thermal for hot water is a far more reasonable position, certainly on new build domestic properties. We all use a lot of hot water, even during the summer and having water heated by solar thermal apart from being really effficient, masssively reduces the (usually) gas burden of heating from a boiler or immersion heater. I also love the idea of a partnership between, e.g. An Underground Station with a limitless supply of heat energy to remove to cool down the stations, and perhaps the hospital next door which uses enormous amounts of hot water. Heat pump anyone?
- kergonath 4y ago
  > I suspect that the elephant in the room is simply money. Who pays? This one is very frustrating. The core of the issue is the lack of long-term strategy. It has been obvious for decades that paying now is orders of magnitude cheaper than bearing the consequences of things like climate change and a dependence on a madman dictator hell bent on revenge with delusions of grandeur. But the practical solutions are screws that we can’t really use with our free-market hammers.
  - ZeroGravitas 4y ago
    We had good free-market solutions that we didn't use either, so I'm not totally sure that free-market thinking is the root cause, unless you're referring to people using 'free-market' as an excuse to do things that help the rich and the powerful, while ignoring 'free-market' things that would help other groups, which is often the case. Probably best to seperate people knowlingly lying about science/politics/economics to suit themselves from the activities themselves, though that can be complicated at times.

It costs more to put them on residential roofs. It is cheap on industrial and warehouse roofs, and extends the life of the roof. But they coexist well with pasture and crop land uses, too, as well as reservoirs and canals. So space for solar is absolutely abundant everywhere.

DoingIsLearning 4y ago
> It costs more to put them on residential roofs. If you mean slanted shingle roofs the installation is still trivial. There are also plenty of flat residential roofs which are exactly the same as an 'industrial' roof.
- jasonwatkinspdx 4y ago
  No, what the comment says above is correct: there's a rather dramatic difference in levelized costs between utility scale solar and rooftop residential solar. Commercial rooftop solar is only slightly better than residential. There's multiple factors that feed into this, such as how much supporting infrastructure is amortized vs scale, being able to design the array for optimal lighting vs working with an existing building, systematic regular cleaning to keep the array working near peak efficiency... lots and lots more details like that. This isn't to say residential rooftop solar is bad. However atm it's something of a vanity project for people who can afford the investment. It is most definitely not some sort of obvious solves the whole problem slam dunk idiots in government are ignoring because they're stupid. They know what they're doing and are focusing on the highest impact places to put funds, and that can scale up a lot faster than fighting NIMBYs. And yeah, I'm really disappointed in Elon's solar roof tile stunt surrounding this.
  - ZeroGravitas 4y ago
    Requiring solar on new builds is a good policy though and is implemented in various German locations.
    - ncmncm 4y ago
      True, retrofitting will always cost more than outfitting during original construction, and having the builder involved enables economy of scale when many (near-)copies of the same house design are built.
  - kergonath 4y ago
    > It is most definitely not some sort of obvious solves the whole problem slam dunk idiots in government are ignoring because they're stupid. The thing is, there is no slam dunk obvious solution. But every bit that helps could be part of a more global solution that has a chance of working. Public transport, better insulation, electric transportation, solar panels and wind turbines where it makes sense, large-scale carbon-free baseline production, etc. We need to do all of that. > And yeah, I'm really disappointed in Elon's solar roof tile stunt surrounding this. Elon is not on the right side of this. His pseudo-ecologist speeches are just window dressing.
- ncmncm 4y ago
  At issue is that a residential roof is no bigger than the residence. That does not make residential installations a dumb idea. They just cost more than alternatives. On very large commercial buildings, a project may claim economies of scale, and support dedicated personnel to keep them operating well. That said, roofs are far from the best place to site solar.

lbriner 4y ago

I suspect that the elephant in the room is simply money. Who pays? I would be happy for the government to pay me to save on my electricity bills by installing PV on my roof but I suspect they might not be so keen on the idea. Loans instead? Maybe, but there are all kinds of issues around what happens if you need to sell the property etc. Same with industrial units. You could have an enormous room that would cost £500K to install PV onto which would be way too much money for most building owners unless the feed-in tariff would cover the cost quickly but why should it? The Energy companies don't want to pay for a feed they might not need at any particularly time of day. Australia had big problems with over-supply of solar at certain times and I believe the rate went negative to try and stop people feeding it in. For me, solar thermal for hot water is a far more reasonable position, certainly on new build domestic properties. We all use a lot of hot water, even during the summer and having water heated by solar thermal apart from being really effficient, masssively reduces the (usually) gas burden of heating from a boiler or immersion heater. I also love the idea of a partnership between, e.g. An Underground Station with a limitless supply of heat energy to remove to cool down the stations, and perhaps the hospital next door which uses enormous amounts of hot water. Heat pump anyone?

kergonath 4y ago
> I suspect that the elephant in the room is simply money. Who pays? This one is very frustrating. The core of the issue is the lack of long-term strategy. It has been obvious for decades that paying now is orders of magnitude cheaper than bearing the consequences of things like climate change and a dependence on a madman dictator hell bent on revenge with delusions of grandeur. But the practical solutions are screws that we can’t really use with our free-market hammers.
- ZeroGravitas 4y ago
  We had good free-market solutions that we didn't use either, so I'm not totally sure that free-market thinking is the root cause, unless you're referring to people using 'free-market' as an excuse to do things that help the rich and the powerful, while ignoring 'free-market' things that would help other groups, which is often the case. Probably best to seperate people knowlingly lying about science/politics/economics to suit themselves from the activities themselves, though that can be complicated at times.