$20,000 for a 6kW system with a 15-20% capacity factor that lasts 20 years means you're going to generate a total of 157,000kWh. That's 12.7c/kWh. Before factoring in anything that might happen to it, including damage, cleaning, replacing your inverter. That is not cheap electricity -- the LCOE of nuclear is 9-15c/kWh. That's within spitting distance of Vogtle before you add storage.
Sure the panels may last 30 years, so you can juice the numbers and maybe you live in the middle of Nevada so you can get the upper end of the capacity factor but I mean, my estimate assumes nothing happens to those panels before the year 2055. My estimate also doesn't include financing costs for your car-sized purchase or any changes to your insurance premiums.
If you add a PowerWall for $15,000 that lasts 10-15 years, that doubles the cost despite increasing the capacity factor of the system, once again assuming you have zero issues with it until 2040.
> A vast number of US homeowners have installed such a system and are very happy they did so.
I'd do it myself and I'd be happy too, because it's neat, but that doesn't mean I'm getting a good deal or that residential solar is a cheap way to get electricity.
I suspect the people who are happy with their financial decision don't understand the difference between opex and capex, and aren't factoring in the opportunity cost of their $20-35,000 investment. If you invest $20,000 in bonds at 5% for 20 years you have $53,000 -- or in the S&P 500 at 9% you have $112,000. Historically electricity prices have grown closer to 2% per year.
Sure the panels may last 30 years, so you can juice the numbers and maybe you live in the middle of Nevada so you can get the upper end of the capacity factor but I mean, my estimate assumes nothing happens to those panels before the year 2055. My estimate also doesn't include financing costs for your car-sized purchase or any changes to your insurance premiums.
If you add a PowerWall for $15,000 that lasts 10-15 years, that doubles the cost despite increasing the capacity factor of the system, once again assuming you have zero issues with it until 2040.
> A vast number of US homeowners have installed such a system and are very happy they did so.
I'd do it myself and I'd be happy too, because it's neat, but that doesn't mean I'm getting a good deal or that residential solar is a cheap way to get electricity.
I suspect the people who are happy with their financial decision don't understand the difference between opex and capex, and aren't factoring in the opportunity cost of their $20-35,000 investment. If you invest $20,000 in bonds at 5% for 20 years you have $53,000 -- or in the S&P 500 at 9% you have $112,000. Historically electricity prices have grown closer to 2% per year.