Warren Buffett has been a big buyer of large solar projects, but he's not showing much love to smaller solar installations that threaten his utilities. Source: SunPower.

Warren Buffett's Berkshire Hathaway (BRK.B -0.01%) has become one of the biggest owners of renewable energy in the U.S. Through Berkshire's subsidiary MidAmerican Energy, the conglomerate has bought $15 billion of wind projects and solar farms built by First Solar (FSLR 2.17%) and SunPower (SPWR -8.41%). That's alot of money, and it wouldn't be a stretch to say that Buffett has a renewable empire. 

But his love for renewable energy may not be as altruistic as it initially seems. NV Energy, a recently acquired utility in Nevada, is fighting rules that would raise the cap on net metering from residential and commercial solar systems. The reason Buffett's company is fighting them shows just what Buffett thinks about renewable energy.  

These are the rooftop systems that have NV Energy so worried. Source: SunPower.

Buffett: Friend or foe?
The battle in Nevada is over a cap on the amount of net metering that's allowed in the state. Right now, a cap of 3% of peak demand can be net metered, effectively limiting the number of rooftops that can go solar.

This is just one of many ways utilities are fighting solar energy before it gets off the ground. In a state like Nevada, there could be a wave of solar installations that would reduce utility revenue, so they see it as a threat if the cap is raised.

From Buffett's perspective, I don't think this is viewed as an environmental or moral issue, like many in the solar industry want to make it out to be. This is about dollars and cents, plain and simple.

It's all about the green
In the past, Buffett has bought wind and solar projects not because they were environmentally friendly, but because they were profitable. Large utility-scale wind and solar projects come with power purchase agreements that can be 20 years or longer and come with billions of dollars in tax benefits, something Buffett can use to offset profits elsewhere. This structure created predictable cash flows for Buffett and often very high returns given his low borrowing costs.

He wasn't buying these projects on principal, but instead because they were good investments. On the same token, he's not fighting raising the cap on net metering because he's against solar energy, he's fighting it because it could cost him money.

Buffett is no solar champion
The lesson here isn't that Buffett is good or bad for the solar industry, it's that he's an investor, plain and simple. He's shown that returns are attractive enough to make investments in wind and solar, and now that rooftop solar is threatening a company he owns, he's going to fight it. No one should be surprised by that.