Larry Caldwell
Super Member
I'm an old guy who remembers when the sun was an energy source before PV panels. I have a nice south wall in my house with an overhang. It's 50 degrees out, and the heat pump has not run today. I let the wood stove go out because it's not needed, but wood is also solar, thanks to all that chlorophyll.For the ROI, I think that a lot depends on your local power costs, local construction/installation costs, and local solar availability. For us the locally high power costs dominated, as did our high installation cost, and relatively poor solar availability. For us, we decided to install solar when my ROI suggested a 7 year return on investment, including capital costs. Electricity rates that rose faster than projected drove the actual ROI to 4.5 years.
I can't say it often enough, but I think the economics of installing solar is hyper local. I've lived places where overcast skies predominate for much of the year, and that is going to make solar a lot less economical for most folks.
That doesn't mean that there might be non-economic reasons to install solar, e.g. grid independence, reducing a fossil fuel footprint, or improved resilience. YMMV (a lot).
All the best, Peter
Those windows cost me $1.50/sf including the insulating cellular blinds I can close at night. The low E glass is not great for solar, but the energy savings are a tradeoff. They do pretty good, particularly since there are 180 sf of glass. I have never considered residential PV, though I have a 100w panel for emergencies and a solar battery maintainer for the tractor in the barn. I have considered industrial PV because I have ~3 acres of 100% south slope. I asked PP&L about it and they laughed at me. I am the last house on the 1200v line, which has been hung together with chewing gum. I'm 3 miles from the nearest 3-phase. Location, location, location. Sigh.
I have considered solar hot water, which would be good payback, but there is no good place to install a tank. Once again, no electricity needed, or not much, and I could build the collector myself. Heating water is half the energy budget of the typical household. My pipe dream

Passive solar windows and wood heat will have to do. There is still a lot to be said for 19th century technology.