Renewable energy has been a hotly debated topic in Washington, DC during the past few years, but one person who isn't listening to the noise is Warren Buffett. Instead, he's putting billions of dollars to work buying wind and solar power plants and, this week, said there's another $15 billion ready to go.

Buffett isn't buying solar panel manufacturers or wind farm installers. Instead, he's buying power plants with 20-year power-purchase agreements and predictable cash flows, much like a bond. First Solar (NASDAQ:FSLR) and SunPower (NASDAQ:SPWR) have benefited from this, selling hundreds of megawatts of projects to Buffett, which they may do again in the future. 

How can you invest in wind and solar like Warren Buffett? Renewable energy yieldcos are starting to hit the market and are a good way to get exposure to these markets. NRG Energy launched NRG Yield (NYSE:CWEN) last year, and SunEdison (NASDAQOTH:SUNEQ) will launch a yieldco later this year. Solar specialist Travis Hoium covers more on Buffett's investments, and how you can invest in renewable energy in the video below.