PBS had a NOVA special or something on solar engery. It mainly centered on Germany. They give special rates for people who have solar panels. They can sell their exses electricity for twice the going rate. Germany is suppose to be the leader in production of solar panels. There is/was a solar steam generator in Nevada that produced electricity for California. It heated a synthetic oil/liquid. That heated water to steam to turn a turbine to generate electricity. There was also a Supermarket on the east coast that rented solar panel from a company to light and heat/cool the store. The economics were long term payoff for both the store and the renting company.
Tom