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This has been the case for years now for pitched residential roofs - they stopped being competitive a long time ago. Thankfully, the impetus for residential ro

by mapt 2y ago

This has been the case for years now for pitched residential roofs - they stopped being competitive a long time ago. Thankfully, the impetus for residential roof solar was always more ideological than practical. There's plenty, PLENTY, of empty unused land within a 95% transmission efficiency (hundreds or even thousands of kilometers depending on tech) of the end user, for all non-island cases.

rconti 2y ago
Yeah. When we bought our solar system, even knowing it was grid-tied, it felt like we'd somehow be generating our own power. As soon as we had it, and I looked at the tiering, time-of-use, etc, and I realized it's all an arbitrage game. I'm selling my roof space and fixed asset back to the power company, and buying power from them.
- ghaff 2y ago
  If solar could reasonably double for me as a way of weathering a several day power outage in the winter, it would be more interesting. But I'm deeply suspicious of anything that has people out in front of Home Depot hard-selling something that often has complex financing schemes. I don't have huge power bills relative to lots of other home costs. So I'll pass.
  - mapt 2y ago
    DIY doesn't come with those asterisks, and DIY with only-thermal power use & energy storage is on the simple side of things. "Help me heat in the winter" is basically the simplest use-case, because you can accomplish it with a south-facing solar fence and some resistors [or an inverter + space heater, or whatever]. Personally I like the idea of a three-season thermal mass store, a big tank of water or pile of sand that you dump heat into when it's sunny, and extract it at will the rest of the day/week.
matharmin 2y ago
That depends on where you live. In my area, labor is cheap and the costs of panels, batteries and inverters came down significantly over the last 5 years. You can now break even on electricity costs for a residential pitched-roof installation in under 5 years. This is without any subsidies, without selling anything back to the grid. Utility-scale solar installations also make a lot of sense, but around here transmission capacity for that is still a massive issue. You can install more transmission capacity, but it's not cheap.
- mapt 2y ago
  > You can now break even on electricity costs for a residential pitched-roof installation in under 5 years. This is without any subsidies, without selling anything back to the grid. This is arguably a false economy. ~75% of costs for the power grid are not in volume electricity generation, but in maintenance. They haven't priced it that way in most places to encourage power-saving and reduce the need for new infrastructure construction, but they'll be forced to if every roof sprouts solar cells. If volume electricity generation is the concern, doing it in a field is dramatically cheaper than doing it on a roof.
Teever 2y ago
I'd like to see the roofs of big box stores and their parking lots covered in solar panels. It would keep cars a lot cooler and would enable very efficient charging stations to be located in the parking lot.
- mapt 2y ago
  A good number of the roofs already are. While more expensive than working in a field, it's way cheaper/safer than working on a tiny residential roof. Parking lots are tougher, but I saw the first one this year.

by mapt 2y ago

rconti 2y ago

Yeah. When we bought our solar system, even knowing it was grid-tied, it felt like we'd somehow be generating our own power. As soon as we had it, and I looked at the tiering, time-of-use, etc, and I realized it's all an arbitrage game. I'm selling my roof space and fixed asset back to the power company, and buying power from them.

ghaff 2y ago
If solar could reasonably double for me as a way of weathering a several day power outage in the winter, it would be more interesting. But I'm deeply suspicious of anything that has people out in front of Home Depot hard-selling something that often has complex financing schemes. I don't have huge power bills relative to lots of other home costs. So I'll pass.
- mapt 2y ago
  DIY doesn't come with those asterisks, and DIY with only-thermal power use & energy storage is on the simple side of things. "Help me heat in the winter" is basically the simplest use-case, because you can accomplish it with a south-facing solar fence and some resistors [or an inverter + space heater, or whatever]. Personally I like the idea of a three-season thermal mass store, a big tank of water or pile of sand that you dump heat into when it's sunny, and extract it at will the rest of the day/week.

matharmin 2y ago

That depends on where you live. In my area, labor is cheap and the costs of panels, batteries and inverters came down significantly over the last 5 years. You can now break even on electricity costs for a residential pitched-roof installation in under 5 years. This is without any subsidies, without selling anything back to the grid. Utility-scale solar installations also make a lot of sense, but around here transmission capacity for that is still a massive issue. You can install more transmission capacity, but it's not cheap.

mapt 2y ago
> You can now break even on electricity costs for a residential pitched-roof installation in under 5 years. This is without any subsidies, without selling anything back to the grid. This is arguably a false economy. ~75% of costs for the power grid are not in volume electricity generation, but in maintenance. They haven't priced it that way in most places to encourage power-saving and reduce the need for new infrastructure construction, but they'll be forced to if every roof sprouts solar cells. If volume electricity generation is the concern, doing it in a field is dramatically cheaper than doing it on a roof.

Teever 2y ago

I'd like to see the roofs of big box stores and their parking lots covered in solar panels. It would keep cars a lot cooler and would enable very efficient charging stations to be located in the parking lot.

mapt 2y ago
A good number of the roofs already are. While more expensive than working in a field, it's way cheaper/safer than working on a tiny residential roof. Parking lots are tougher, but I saw the first one this year.