There is a wonderful booklet on the web by one of the provincial governments of Canada about solar heating. If I can find it, I will post the link. It was one of the things that convinced me that solar would work in New York.

I don't know the exact numbers, but the study said that solar is quite feasible in Canada and there were (at the time) something over 50,000 installations.

One of the nicest things about solar is that it extends the season almost pain free, making the opening, cleaning, etc all worth it. The downside is slow recovery after a big rain (like we are getting now).