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> 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

> 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.
- efields 4y ago
  20 year payback horizon for us in MD, USA. And that's still would only covering 20-40% of our annual electric usage. We have a fully electric house. It doesn't take more than a couple trees in the wrong place to make you a lousy candidate for solar.
  - Brian_K_White 4y ago
    Meanwhile a relatives system failed before 2 and is now a pile of panels leaning on the side of their house. No way these things are actually lasting 20 years. Or if they are, it's by dint of enough repair & maint to destroy the math even more. What does seem to be true though is that it's getting better/closer. As the panels get both more efficient and cheaper, it becomes less of a waste of motion.
    - idiotsecant 4y ago
      Like anything else you can buy quality components and install them correctly or you can buy poor quality components and install them poorly. If a solar system fails after 2 years there were defects in materials or worksmanship. A solar setup is a pretty robust thing when done right.

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.

efields 4y ago
20 year payback horizon for us in MD, USA. And that's still would only covering 20-40% of our annual electric usage. We have a fully electric house. It doesn't take more than a couple trees in the wrong place to make you a lousy candidate for solar.
- Brian_K_White 4y ago
  Meanwhile a relatives system failed before 2 and is now a pile of panels leaning on the side of their house. No way these things are actually lasting 20 years. Or if they are, it's by dint of enough repair & maint to destroy the math even more. What does seem to be true though is that it's getting better/closer. As the panels get both more efficient and cheaper, it becomes less of a waste of motion.
  - idiotsecant 4y ago
    Like anything else you can buy quality components and install them correctly or you can buy poor quality components and install them poorly. If a solar system fails after 2 years there were defects in materials or worksmanship. A solar setup is a pretty robust thing when done right.