Peco Energy Co.'s new natural gas delivery rate will change on Jan. 1, the company says.

An average monthly residential bill of $110.29 will increase by $10.82, or 9.8 percent, the company said in a release. The average monthly commercial bill of $531.97 will increase by $50.11 or 9.4 percent. The actual impact will be based on usage.

The rate changes the monthly service charge (from $7.20 per month to $10.75 a month for residential customers) and Peco's gas delivery, or distribution charge, which is based on usage (from 28 cents per hundred cubic feet to 36.4 cents per ccf).

Peco decreased the gas commodity charge - which reflects the actual cost of the gas - by 18.8 percent on Dec. 1 based on lower market costs, saving residential heating customers about $50 a month. That change earlier this month kept gas rates at roughly the same level as December 2007. That charge won't be affected by the other increases.

The distribution charge covers the cost of moving the natural gas from the regional interstate pipelines to local customers and gives PECO funds to maintain and upgrade the distribution system, buy equipment and materials, and other operational expenses.