You may not know it but Warren Buffett is actually one of the biggest renewable energy investors in the world. He's spent $15 billion buying up wind and solar farms that not only create clean energy but also generate consistent cash flow and return on his investment.

He recently said that he has another $15 billion ready to buy more renewable projects and there are some investments emerging that he should love in the renewable energy business.

First Solar has been one of the largest utility project builders in the world, projects that can be sold to new YieldCos. Source: First Solar.

What Warren Buffet has bought
Buffett has spent around $15 billion buying wind and solar projects that generate consistent cash flows year after year. Before he buys or builds them these projects generally have long-term (20-year) power purchase agreements that guarantee a rate for every kW-hr of electricity they generate.

SunEdison is now building projects around the world, like this one in Chile. Source: SunEdison.

So far, Buffett has acquired 4.8 gigawatts of wind projects and 1.3 gigawatts of solar projects, primarily from SunPower (NASDAQ:SPWR) and First Solar (NASDAQ:FSLR). He owns the 579 megawatt Solar Star that SunPower is currently constructing near Rosamond, California.

He may continue to buy projects outright but there's also a YieldCo strategy emerging that he can use to get similar exposure and still own renewable assets. The good news is that you can buy YieldCos that are hitting the market more frequently all the time.

Why Buffett should love the YieldCo
YieldCos are similar to MLPs in oil & gas and REITs in real estate in that they own assets that give off cash flow that's then paid to investors. What they own may differ between different YieldCos, especially as the industry evolves.

Right now, there are two YieldCos to keep an eye on. NRG Energy launched NRG Yield (NYSE:CWEN) last year and the company owns not only solar and wind assets but also some fossil fuel generators that allow them to use renewable tax benefits. NRG Energy has been very aggressive in adding solar assets in recent years and we could see them push renewable assets down to NRG Yield in the future.

This SunEdison project for the Air Force is another example of the military looking for renewable energy. Source: SunEdison.

SunEdison launched TerraFrom Power (NASDAQ:TERP) on Friday and it had a booming debut on the market. This is really the first solar-only YieldCo launched thus far and we can expect that to continue as SunEdison pushes future projects down to its spinoff. Initially, the company will have 807.7 megawatts of nameplate production according to the S-1 including 134.8 megawatts of distributed solar projects, which are rooftop residential and commercial systems. 

In the future, I would expect to see SunPower and First Solar also launch YieldCos because they own the perfect assets for such a company and a long history of power plant performance. Until then, they'll both benefit by selling projects to YieldCos. 

Investing like Warren Buffett
It's not possible for us to buy multi-billion dollar projects the way Warren Buffett can but it is now possible to invest in solar projects similar to what he does. Renewable and solar energy YieldCos have opened a new opportunity in the market and provide exposure to these energy sources without the risk of owning a manufacturer. That's why Warren Buffett likes them and if you're looking for similar exposure they may be a good investment for you too.