I have PV on my roof, by the way.
I installed it not to save electricity, but to save energy. While I'm not bashing PV, and think it will make more sense in the future as the price of panels drop and the price of electricity rises, I don't really expect that I'll ever recoup the cost of installation.
Compare that to solar thermal, which is not only greener (PV panels are made with toxic chemicals and lots of energy) but actually starts saving you money after five to six years of ownership.
Yeah, they can be complementary systems, but if you're going to chose one over the other, solar thermal wins IMO.