NRG Energy said on Monday it would acquire power generation assets from energy infrastructure investment firm LS Power in a deal valued at $12 billion, as the U.S. utility bets on surging electricity demand,

The deal, to acquire a portfolio of natural gas generation facilities from LS Power Equity Advisors, will double NRG’s power-generation capacity, the company says.

NRG Energy has entered an agreement to acquire LS Power Equity Advisors’ natural gas generation facilities and a C&I VPP platform portfolio.