Duke Energy asks for energy-saving during cold snap

Duke Energy is asking its 4 million customers in the Carolinas to reduce their electricity use over the next 24 hours, when temperatures are expected to plunge.

The National Weather Service expects a Wednesday night low in Charlotte of 13 degrees with highs on Thursday reaching only 28.

Duke’s appeal is aimed at avoiding high energy demand on the electrical grid during the cold snap, reducing the potential for power outages. Cold weather slows down the electrical equipment that moves electricity across the grid.

Duke Energy Carolinas, which serves Charlotte, hit a new winter usage peak when the polar vortex hit one year ago. Temperatures on Jan. 7, 2014, reached 6 degrees in Charlotte and 8 degrees below zero in Boone.

The most critical times to reduce electricity use will be Thursday between 5 a.m. and 10 a.m., Duke says. Those are also the hours when households are cranking up thermostats as they prepare for work and school.

Duke’s own plan to manage the extreme conditions includes running all available generating units, triggering voluntary customer programs that reduce electricity demand and buying power from other utilities.

Its final option, if electricity demand outstrips the amount of energy generated, is to reduce power. That could result in rotating or extended power outages.