The Electric Reliability Council of Texas, operator of the state’s power grid, said in a report today that a new federal environmental regulation would reduce generating capacity and put the grid “at increasing risk of emergency events,” including rotating power outages.

The Jan. 1 implementation date for the Cross-State Air Pollution Rule, designed to curb air pollution from power plants, leaves ERCOT with “an extremely truncated period” in which to assess the impact of the rule and “no realistic opportunity to take steps that could even partially offset the substantial losses of available operating capacity,” it said.

The report outlined three scenarios, with even the “best-case scenario” expected to result in the loss of an estimated 1,200 to 1,400 megawatts of generating capacity during peak consumption periods, ERCOT said.

“Had this incremental reduction been in place in 2011, ERCOT would have experienced rotating outages during days in August,” the report said.