Here’s another reason to be nice to the neighbors: They might just give you a no-money-down, low-cost loan to put solar panels on your roof, and once you pay off that debt you’ll get essentially free electricity as long as you own your home.

Welcome to the latest innovation in renewable energy: The crowdsourced solar loan.

The loans are administered by Mosaic, an Oakland, Calif., startup that made its name by letting ordinary investors – that’s you and me – put money into commercial and non-profit solar projects that were once the exclusive domain of big banks and corporations like Google.

In the coming months, the environmentally minded can go to Mosaic’s site and invest in portfolio of 20-year loans made to homeowners. (Each individual loan will be scrubbed of identifying information.) Mosaic is offering the loans through a partnership with solar installer RGS Energy.

The interest rate is 4.99 percent as long as homeowners pay down the loan with a 30 percent federal tax credit they’ll receive for installing a solar system. If they keep the tax credit, the rate jumps to 10 percent after 18 months.

“We think a solar loan if structured right can open up the market and make solar more affordable and accessible for more homeowners,” Mosaic co-founder Billy Parish told The Atlantic.