Central Ohio residents likely will pay an estimated 19 percent more than usual to cool their homes this summer, said Robert Burns, researcher at the National Regulatory Research Institute at Ohio State University.
Besides the current heat wave, temperatures also were above normal in May and June.
"For each day the nights stay around 70 degrees and the days stay in the 90s, your bill will be 1 percent more for the summer," he said. One example of how weather can affect your bill: In August 2004, American Electric Power customers in central and southern Ohio, on average, used 950 kilowatt-hours of electricity and paid $80.21.
In August 2005 and 2006, when the weather was warmer, average usage rose to about 1,200 kilowatt-hours, and average bills increased to $103.
15 and $114.51, respectively, the utility said. The good news: There's no shortage of electricity.
That's partly thanks to conservation - Americans buying more fuel-efficient appliances and taking other measures - and because large natural-gas supplies left over from a mild winter now can be used to generate electricity, Burns said.
And even though this summer has been hot, energy use has not matched peaks set in August 2006 - at least, not yet.
After the heatwave, forecasters predict a cooler weekend. "One hopes that they're right," Burns said. AEP, which provides electricity to 1.4 million Ohioans, is not worried about heat-related outages and has not asked customers to turn down air conditioners or conserve electricity, spokeswoman Melissa McHenry said.
During heat waves, AEP takes steps to ensure it can meet demand. The utility makes sure no power plants are shut down for maintenance at this time of year. AEP also recently acquired four natural-gas-powered operations as backups when customers are running air conditioners at full blast.
"We're accustomed to having warm temperatures," McHenry said. "We have capacity to meet peak demand." AEP customers in central and southern Ohio set a high for 2007 on August 6, using 4,379 megawatts of electricity. That's still below the record of 4,431 megawatts set Aug. 1, 2006.
The figures are based on one-time highs set during the day.
A megawatt of electricity can power 800 to 1,000 homes. Meanwhile, PJM Interconnection, the interstate grid that covers AEP's Ohio customers, hasn't been taxed as much this summer. On Aug. 2, 2006, the 51 million customers on PJM's grid used a record of nearly 145,000 megawatts.
The high for PJM this summer was July 9, when more than 136,000 megawatts were used. The high temperature that day in Columbus was 92.
"We do not forecast to hit last year's peak for at least the next seven days," said Ray Dotter, PJM spokesman. "We're forecasting it to be a little higher (today), but still below the record."
With temperatures rising, PJM is keeping a closer eye on its states east of Ohio. Those areas can generate less electricity relative to residents' demands. PJM covers 13 states and the District of Columbia. "Most of the (generating) capacity is on this side of the Appalachians," Burns said.
"And when you look at the (natural) gas pipeline system, we have far more gas capacity on this side of the Appalachians."