Crowdfunding may supply the rooftop solar projects with $5 billion of investment within five years, more than 50 times the amount raised to date. That would represent more than a quarter of all annual investment in that segment of the solar industry, said Tim Newell, vice president of financial products for San Mateo, California-based SolarCity Corp., which is the biggest U.S. solar power provider by market value.
A growing number of rooftop solar developers are soliciting funds directly from retail investors, often through websites that tap a large number of small contributions. This so-called crowdfunding model has attracted almost $100 million in the U.S. to date, Newell said. It offers one of the few ways for individuals to back renewable energy projects, which give steady, long-term returns from selling electricity.