Some of the chill coming out of Avista bills

A steady decline in natural-gas prices will mean lower energy bills for Avista Utilities customers in Washington and Idaho.

Effective Sunday, Washington residential and small-business customers will see natural gas rates cut by 25 percent.

Avista’s Idaho customers will see a decrease of 23 percent, said Brian Hirschkorn, pricing manager for Avista Utilities.

Regulators in both states approved the cuts this week. Spokane-based Avista initially wanted to make those energy bill refunds to customers over two years to “offset price volatility,” Hirschkorn said.

But on Wednesday the Idaho Utilities Commission said Avista had to issue gas refunds to customers over the next year. Washington’s Utility and Transportation Commission agreed Thursday.

As the economy has stalled, lower demand for natural gas and steep cuts in wholesale gas prices have eased the effects of the recession just slightly for residents opening their utility bills.

Natural-gas companies are required to adjust rates periodically to reflect changes in wholesale prices. About 75 percent of an Avista customer’s monthly bill is attributable to the cost of natural gas. Regulators also require energy utilities to charge customers only for the costs incurred in buying natural gas.

In Washington, the average customer using 70 therms of natural gas a month will save $20, for a bill of about $59 a month.

A residential customer in Idaho using an average 66 therms a month could expect their bill to decrease by $17, for a revised monthly bill of $57.

A therm is equal to 97 cubic feet of natural gas, or roughly 29 kilowatt-hours of energy.

This week’s natural gas price adjustment is the third one approved by the utilities commissions this year. For Washington customers, the total cut is about 37 percent, Avista spokeswoman Debbie Simock said.