MidAmerican Energy, a Berkshire Hathaway (BRK-A) subsidiary, announced on Wednesday the $10 billion purchase of the Nevada-based NV Energy (NVE), a supplier of electricity and natural gas to more than one million residents of the state.

NV Energy, with a market cap of $4.54 billion, is perhaps not the elephant for which Warren Buffet has been hunting in the wake of the huge deal for Heinz earlier in the year. All the same, the buy is in keeping with what has been a busy year for MidAmerican in terms of M&A in green energy companies.

In the first days of 2013, MidAmerican announced the acquisition of a 579-megawatt solar project in Southern California. The Antelope Valley Solar project’s combined operations in Kern and Los Angeles counties are expected to comprise the world’s largest solar plant when fully operational in 2015, with the capacity to serve nearly one million residents. MidAmerican bought the project from Sunpower Corp. (SPWR) for more than $2 billion.

Last month, the holding company announced plans to spend $1.9 billion on 650 turbines that would bring 1 gigawatt of wind power to Iowa’s energy grid by 2015. MidAmerican is also Iowa’s largest utility.

Wednesday’s acquisition offered $23.75 per share in cash to purchase all outstanding shares of the company’s stock, sending NV Energy spiking over 23 percent in late trading to $23.73, after closing the regular trading day on a 2.4 percent loss at $19.28. The transaction is set to be finalized by early 2014, pending a vote by NV’s shareholders, as well as state and federal approval.