Severe winter weather can cause icing and other mechanical problems for electricity generating units. For example, in February 2011, 225 units in the Southwestern U.S. were tripped, de-rated or failed to start entirely due to frigid temperatures and high winds. Both the “polar vortex” that enveloped much of the Eastern U.S. in January 2014 as well as the February 2021 cold weather event caused similar problems. MISO urges asset owners to ensure that generating units are adequately weatherized. This will help fend off forced generation outages that can jeopardize grid reliability.
NERC, the reliability authority for the bulk power system, found that many of the forced outages associated with the February 2011 severe weather event occurred because generators failed to adequately prepare for frigid temperatures and high winds. NERC said all types of generation except nuclear exhibited weatherization-related shortcomings, including:
NERC issues 13 "lessons learned" in the wake of that event that it urged generators and other entities to implement to reduce weather-related forced outages. NERC's findings, which MISO supports, recommend that generators consider taking a number of action as part of their winter operation plans, including:
NERC's other weatherization-related recommendations address subjects such as maintenance and inspection practices; fuel-switching procedures; and winter operations training for unit operators, among other things. NERC's 13 recommendations that grew out of the 2011 severe weather event can be found on NERC's website.
NERC's report on the 2014 polar vortex also addresses weatherization-related issues and can be found on NERC's website.