February 17, 2021 Federal regulators warned Texas that its power plants couldn’t be counted on to reliably churn out electricity in bitterly cold conditions a decade ago, when the last deep freeze plunged 4 million people into the dark. They recommended that utilities use more insulation, heat pipes and take other steps to winterize plants — strategies commonly observed in cooler climates but not in normally balmy Texas. “Where did those recommendations go, and how were they implemented?” said Jeff Dennis, managing director of Advanced Energy Economy, an association of clean energy businesses. “Those are going to be some pretty key questions.” As investigators probe the current power crisis in Texas, which has left millions of people without power or a promise of when it will be restored, questions are sure to be raised about how the state responded to the urgings from the 2011 analysis, issued by the Federal Energy Regulatory Commission and the North America Electric Reliability Corporation, which sets reliability standards.