When Warren Buffett talks, investors listen.

And today's revelation that Berkshire Hathaway (NYSE: BRK-B) subsidiary MidAmerican Energy Holdings is buying the 550 MW solar power plant being built by First Solar (Nasdaq: FSLR) should have every energy investor's ears perking up. The project will cost over $2 billion, no chump change even for Buffett, and adds to MidAmerican's large portfolio of wind generation assets.

What this means
If you didn't believe in solar power until now, all you have to do is look at some of the major companies putting money into solar. NRG Energy has bought a number of solar plants to add to its generation portfolio, Total (NYSE: TOT) bought a majority stake in SunPower (Nasdaq: SPWR) earlier this year, and now Berkshire Hathaway is making a bet on solar.

What this means right now is that solar power-generating assets are providing attractive returns to investors. If they weren't, Buffett would have nixed the deal in a heartbeat. The only manufacturer investment above, SunPower, also comes with a large project pipeline, so the projects are what companies are after right now.

What this doesn't mean
Solar power plants are assets with a known cost and predictable cash flows, something investors can easily gauge the return on. What we haven't seen is companies going out and buying manufacturers in this environment.

So solar products themselves are attractive, but that doesn't necessarily mean the manufacturers that make them are. That shouldn't come as a major surprise to those who have watched LDK Solar (NYSE: LDK), JA Solar (Nasdaq: JASO), and ReneSola (NYSE: SOL) bludgeon one another for sales this past quarter. Right now there is a lot more risk in solar manufacturers than there is in solar power plants.

Foolish bottom line
If you're looking to get into solar, there are a few ways to do it. NRG Energy provides a growing exposure to solar power plants from the power generation side. But if you have an appetite for risk, SunPower and First Solar provide both manufacturing as well as power plant development and sales. My top pick is SunPower because of its industry-leading efficiency.

Are you surprised Buffett is making moves in solar? Leave your thoughts in our comments section below.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.