[paredown]

I have not looked into solar panels recently, because we are too shaded to see much benefit. But a number of years ago, my build partner and I were asked to look at them for a commercial business--IIRC,the break-even was about seven years. (This was a classic flat roof, fairly large commercial building from the 1960s, and the estimate was that it would cover 100% of the building's demand.) They decided not to go ahead with the project.

While we were involved in that my partner got the same company (Sunrun?) to install panels on her roof--she lives up the street on a sunnier lot. (Already had a new roof, so that was good--and the installers were super professional.)

We're in the Hudson Valley, so lots of grey days, snow etc, but they have generated enough to cover their needs, typically building up a credit during the summer days and have covered the lease payments as well, even though our local power company is not known for their generous terms... They are well past payback and everything still works great.

We also looked at ground source geothermal for our house--we had one of the young guys from Dandelion come and (try to) estimate. Tl; dr--it seems as if geothermal would not be cost effective for retrofits and would work much better in a new build situation (which is what our friends (whose system I admired) had done. (I also had the more traditional guy who did our friend's installation and the back of the envelope was over $30,000 ten years ago.