Wind energy is expected to overtake coal in Texas after Friday's news that two large coal-fired power plants are set to close in the next year. The utility firm Luminant announced that it would close the Sandow Power Plant and the Big Brown Power Plant in early 2018. The power plants comprise 2,300 megawatts of electricity, which means 2.1 million homes in the Lone Star State will no longer be powered by coal.That gap in electricity generation is projected to be filled by wind farms in the Texas energy grid known as ERCOT, according to an analysis issued by the University of Texas at Austin's Energy Institute soon after Luminant's announcement.