SPRINGFIELD, Mass. (WWLP) – Your energy bills could go up this winter, if you use natural gas. National Grid submitted their proposal to the state to increase natural gas prices last Friday.

If approved, a typical residential natural gas customer would see a roughly $14 increase in monthly bills, beginning in November. That is in contrast to last year, when customers saved an average of $5 each month through bill credit. That credit, however, has expired.

There are two sides to your natural gas bill: the supply side, which is based on the cost of the gas itself. Rates have gone up slightly over the years, but that is not the biggest factor, according to National Grid spokesperson Danielle Williamson. It is changes to delivery, she says.

“First, National Grid is reconciling the difference between what we billed customers for delivery last winter and the revenue needed to support delivery services. And secondly, the increase is due toward the work that National Grid has done to improve system safety and reliability through our leak prone main replacement program,” Williamson said.

That includes replacing gas mains throughout the state that have leaks.

Columbia Gas of Massachusetts, which provides natural gas service for much of western Massachusetts, was already approved for a rate hike, which will start November 1.

There are billing programs to help customers spread payment out over the year. Click here for more information.