Motionless windmills, solar plant glitches, shuttered coal plants and low water levels create a recipe for widespread
power outages this summer, the country’s leading watchdog on power grid reliability warns. An assessment from the North American Electric Reliability Corp. found that electrical grids powering two-thirds of the U.S. are “at risk of energy shortfalls” during summer heat waves.NERC officials warned Congress that the threat will likely worsen unless the U.S. “recalibrates” its effort to transform the nation’s power grid to renewable energy by focusing on reliability.