The Solar Energy Industries Association reports more than 100,000 rooftop solar projects were completed in 2014; that number is expected to double this year and double again next year.
Meanwhile, Bloomberg New Energy Finance predicts that by 2016 utility-scale solar projects will be competitive for a majority of the world and $3.7 trillion will be invested in solar projects between now and 2040. That's a lot of cells.
Further, says Bloomberg Business: "The biggest solar revolution will take place on rooftops. High electricity prices and cheap residential battery storage will make small-scale rooftop solar even more attractive, driving a 17-fold increase in installations. By 2040, rooftop solar will be cheaper than electricity from the grid in every major economy, and almost 13 percent of electricity worldwide will be generated from small-scale solar systems."
Now, that's pretty heady stuff. What's driving such massive change? Two things, of course: The prices of solar projects have been cratering, and their efficiencies have been improving dramatically. And what's interesting about the predictions cited is they don't mention tax and utility-provided incentives, which, so far, have been driving the solar industry.