More Videos:

Warren Buffett Should IPO MidAmerican Energy Now

Tickers in this article: BRK.A BRK.B FSLR GE SPWR STCY

All told, by 2015, MidAmerican will be a leading green energy player in the U.S. - to go with larger conventional energy businesses in natural gas and coal.

However, as U.S solar manufacturers complete controversial DoE financed plants in some political circles, their survival will depend on a next round of investment, this time likely without billions in government loans.

Berkshire's MidAmerican Energy and similar solar moves made by Exelon and others may be the investments that prove whether or not the green energy sector makes financial sense. Meanwhile, outside of California, most states are yet to map out renewable energy generation goals, as climate change recedes from President Obama and Congress's agenda.

Out in public markets, MidAmerican Energy could be the sort of capitalist spokesperson for the renewable energy industry, which still suffers from the cloud of Solyndra and the politically charged stimulus program, in addition to the disappointing stock performance of First Solar and SunPower.

An analogy would be Elon Musk's Tesla Motors (TLSA) , which appears to be making an investor case for the mass-market electric car. Musk also recently IPO'ed a solar investment called Solar City (STCY) , which makes rooftop solar systems that can power small businesses and individual households. One day he may also be responsible for the first space shuttle stock.

Still, as with the banking industry in 2008, green energy needs a spokesperson - and there appears to be no one more vocal or better positioned than Warren Buffett.

With the financial crisis largely resolved and a partisan debate on the taxation of the rich also in the rear-view mirror, Buffett may also be on the lookout for a new cause.

For more on Warren Buffett's investments, see why he may direct his elephant M&A guns at utilities. Also see four investors who could pick up the 'Oracle of Omaha's investing mantle .

-- Written by Antoine Gara in New York