Bitcoin needs to be mined with “wasted” or “stranded” energy in order to be cost effective. IMHO, solar with a battery backup is a way to mine, at least intermittently, in a cost effective way.

During the day, once your batteries are fully charged excess solar output is “shunted to ground” or, simply put, wasted. By running miners only when you are “wasting” excess solar generation your energy cost is effectively zero.

Cons: high initial cost

Intermittent mining

Pros: reasonable ROI. Solar will pay itself back in 3-5 years. Average battery life is 10 years, panels-20 years.

You get off the increasingly fragile electric grid.

Even if your miners only average running a couple hours a day that’s still over 1000 hours of mining a year. That’s a far better return than selling energy back to the utility company for pennies on the dollar.