The following opinion piece from America’s Power appeared in Power Magazine:
So far, utilities have announced plans to retire some 93,000 MW (nameplate) of coal—almost half the existing coal fleet—by the end of this decade. Coal retirements combined with increasing penetration of wind and solar power are the major cause for concern about generating capacity shortfalls in many regions of the country, especially during extreme weather.
The North American Electric Reliability Corporation (NERC) is responsible for grid reliability across the U.S. and parts of Canada and Mexico. In 2015, NERC gave subtle warnings about the possibility of reliability problems. “The North American Bulk Power System (BPS) is undergoing a significant change in the mix of generation resources and the subsequent transmission expansion … [T]he rate of this transformation in certain regions is impacting planning and operating of the BPS,” it said.
By late last year, NERC’s warnings had become more direct. “The BPS has already seen a great deal of change and more is underway. Managing this pace of change presents the greatest challenge to reliability. … Energy risks emerge when variable energy resources (VER) like wind and solar are not supported by flexible resources that include sufficient dispatchable, fuel-assured, and weatherized generation,” it cautioned.