Friday, September 10, 2010 9:47 am

Middle Tennessee Electric set an all-time usage record this summer as electric consumers coped with consistently hot weather … and correspondingly higher power bills.

The cooperative set a new record demand peak of 1,313 megawatts during the afternoon of Aug. 4, when temperatures of more than 100 degrees gripped the area.

“It meant a lot of people where using a lot of power at the same time,” said Chris Jones, MTEMC vice president of communications and member services. “Though there were many factors, it means we were all trying to keep cool, and we had to use a lot of power to do it.”

It was a similar story for much of the summer. According to the National Weather Service, the mid state experienced its third hottest summer (June, July and August) on record. Adding to the misery was consistently high humidity, which made it feel even worse and made air conditioners work even harder.

“It was a recipe for high consumption and high bills,” Jones said. “For residential members in particular, extreme weather has a pronounced effect on usage patterns.”
 
Jones said the consistently high temperatures and humidity over the summer months caused most cooling systems to work overtime.

“Sometimes our members have difficulty believing how much power they used, and I sympathize with that,” he said, “but when a cooling system works hard almost continuously, it racks up the kilowatt-hours. On average, a heating-and-cooling system accounts for 50-60 percent of a residential member’s bill, but in extreme weather, the percentage is even higher.”

With the hot weather in place across the Tennessee Valley most of the summer, TVA also experienced abnormally high consumption and demand totals. This drove up costs for the power supplier, Jones said.

“The more power consumers use, the more expensive it is for TVA to supply the demand,” Jones said. “That’s because TVA has to engage more expensive resources to meet higher demand. On a pleasant day, TVA’s dams, nuclear plans and coal-fired plants can meet the demand. But when it gets very hot and demand shoots up, TVA has to use plants powered by natural gas, or they have to purchase power on the open market – these resources are much more expensive.”

While TVA’s costs for producing each kilowatt shoot up during a summer day, MTEMC members are charged the same cost per kilowatt-hour despite the time of day. However, Jones said that could change as soon as next year.

“TVA will be moving to a rate structure that will more accurately charge us,” he said. “When it’s more expensive for them to provide the power, it will be more expensive for us to use it. When it’s cheaper for them, it will be cheaper for us.”

Jones encouraged members to look for more information early next year about the coming rate structure changes.