Raleigh, N.C. — Some Progress Energy customers say they are seeing a much bigger jump in their utility bills than the 10 percent rate increase that the state approved went into effect last year.

"Every once in a while, we'll have a mild week, and so folks here at our customer service center will have some folks (calling) wondering why their bills are so high," Progress Energy spokesman Mike Hughes said.

The state Utilities Commission approved a rate increase that went into effect in December. Under it, an average bill of $96 would increase to about $106

There could be a number of factors behind increases larger than 10 percent, Hughes said, including using heating systems more in the dead of winter to get a home to a comfortable level.

The cost of fuels used to generate electricity has also increased, he said.

Sara Moody said she saw her winter bill, usually about $120, increase in December to $182.

"I figured, maybe it will be lower next month," she said. "And then, when I got the next month's bill, it had gone up more. It was $190 and some few cents."

Moody said she is not complaining about the increased cost of utilities, but is concerned if it keeps increasing.

"Right now, I'm OK," she said. "You know, but if things go up, you know, I don't know if I'll be OK."

Progress Energy does offer free advice at savethewatts.com on how to reduce energy bills.

Hughes said the company also can set up payment plans for customers having trouble paying their bills.