It's hard to know where Berkshire might want to expand in the utilities business. NV Energy seemed a perfect fit for MidAmerican's increasing exposure to western power markets and its deployment of billions in capital on renewable energy projects.

In a 2012 column, TheStreet pointed to NRG Energy (NRG) as a company that MidAmerican has partnered with on many renewable energy projects. The company's market capitalization of less than $10 billion would also fit within Berkshire's elephantine deal parameters.

On the East Coast, where MidAmerican has little exposure, utilities are suffering. Exelon (EXC) is currently mired in a four-year slump that's seen the company's share price fall from nearly $50 a share at the beginning of 2010 to just $30.30 a share as of Monday morning trading.

Jefferies utilities analyst Paul B. Fremont recently equated a recovery at Exelon to "waiting for Godot," given forecasts that gross margins will continue to fall at the company through 2016. Maybe, in Exelon's case, Buffett's MidAmerican Energy unit can play the savior role.

Given Jefferies analyst Fremont's price target of $24 a share for Exelon, continued underperformance could put the $26 billion market cap company within the reach of Berkshire's elephant guns.

It's also worth noting that Berkshire Hathaway attempted to buy Constellation Energy in the market panic of 2008, after providing the company $1 billion in preferred financing. However, Berkshire's proposed $4.7 billion takeover fell apart and Constellation was eventually sold to Exelon or $7.9 billion. Maybe Buffett and MidAmerican will eventually get their deal.

"A century hence, BNSF and MidAmerican Energy will still be playing major roles in our economy," Buffett said in his 2013 investor letter.

If Berkshire is playing the 100-year game, Consolidated Edison (ED), the nation's oldest electric utility may be another East Coast utility to watch. Since Superstorm Sandy battered the greater New York, New Jersey and Connecticut regions in October 2012, ConEd's shares have fallen from above $60, given recovery capex and a political maelstrom from duration of some power outages.

After ConEd agreed to a new two-year rate settlement with the New York Public Service Commission (NYPSC) that contained no revenue increases, Fremont, the Jefferies analyst, upgraded his rating on the stock to 'hold' from 'underperform.' ConEd said in February it will invest nearly $1 billion in capex for solar energy projects in its unregulated business.

Buffett said Berkshire Hathaway will always keep $20 billion in cash in the company's bank account to maintain financial flexibility. He also said Berkshire will carefully weigh any share issuance for acquisitions, a strategy the company employed to buy railroad BNSF in 2009.

Berkshire Hathaway reported year-end 2013 cash and cash equivalents of over $42 billion, meaning few utilities deals are out of the company's reach.

-- Written by Antoine Gara in New York

If you liked this article you might like

How to Make Your Life Successful Just Like Billionaire Warren Buffett

How to Eat Lunch With Billionaire Warren Buffett

How to Travel in Style Exactly Like Billionaire Warren Buffett

Billionaire Warren Buffett Thinks U.S. Haters Are 'Out of Their Minds'

How to Invest Like Billionaire Warren Buffett