The temperature in Embreeville, TN was 7 degrees at 1 p.m. Tuesday as an ice floe traveled down the Nolichucky River under the Alfred A. Taylor Bridge on Highway 81 S. (Lee Talbert/Johnson City Press)
With heat pumps and water heaters across the southeastern United States working overtime Tuesday morning to combat the frigid temperatures delivered by a weather phenomenon known as a polar vortex, skyrocketing demand led to supply problems for many electric utilities.
In Western North Carolina, the Asheville Citizen-Times reported 15,000 Duke Energy customers were without power Tuesday morning, partially caused by equipment failure brought on by increased usage.
Expecting and observing a spike in electricity usage Tuesday morning, as millions of residents in seven states awoke and began taking hot showers and using electrical appliances, the Tennessee Valley Authority issued an alert to 155 local power companies, including the Johnson City Power Board, asking them to encourage customers to conserve electricity during peak morning hours.
JCPB spokesman J.T. McSpadden said the local utility issued the alert about 8 a.m., and the bulk of the threat had passed by 10, when demand began to decline.
According to information released by the TVA, the agency reached a peak power demand at 8 a.m. of 32,490 megawatts, the second highest winter peak since Jan. 16, 2009, when temperatures across the Tennessee Valley averaged 9 degrees and demand reached 32,572 megawatts.
TVA’s all-time demand record is 33,482 megawatts, set on Aug. 16, 2007, when temperatures averaged 102 degrees.
McSpadden said part of the problem with the heightened demand Monday and Tuesday lie with the region’s ability to generate electricity.
“Traditionally, when power generation is insufficient to meet demand, TVA will go to the open market and buy more,” he said. “With the widespread, single-digit temperatures across the southeast, there wasn’t much excess available on the market, because almost everybody was buying it.”
McSpadden said the demand load sent TVA and its distributors to step 30 of a pre-defined contingency plan, which means customers are issued a widespread plea to reduce use.
Had demand risen much more, heavy industrial users holding agreements with TVA would have been contacted and had their power shut off to avoid supply problems to residential users.
McSpadden said there is a potential for a similar alert Wednesday morning if temperatures in the south remain low, but said TVA won’t know if demand is outpacing generation until usage information starts coming in.
“In my career here, this is unprecedented, we haven’t seen temperatures this cold in 20 years,” he said.
While the full TVA system is generally summer peaking, with many customers in warm-weathered southern climates, McSpadden said the JCPB general experiences winter peaks because of the lower temperatures at its more northern location and higher elevation.
Near midday Tuesday, McSpadden said the JCPB wasn’t experiencing widespread outages seen in western North Carolina, and only had 32 customers without power.
By 6 p.m., that number was reduced even more to only two customers.
The region will finally start to thaw today as temperatures are expected to climb into the mid-30s today with sunny skies, according to the National Weather Service in Morristown. A low of 18 is forecast tonight.
A high of 43, with a low of 32 are expected Thursday.
By Saturday, the high temperatures are expected to be in the mid-50s.