Electric rates for Avista Utilities’ Idaho customers increased 4.2 percent effective Wednesday through a surcharge that allows utilities to recover costs from the previous year that weren’t included in base rates.
Avista’s request for increase was approved by the Idaho Public Utilities Commission. For a residential customer using Avista’s average of 930 kilowatt hours of electricity per month, an average monthly bill would increase by $3.76, from $81.88 to $85.64.
The increase allows Avista to recover $7.7 million in power supply expense needed to serve customers that wasn’t included in base rates, according to PUC staff.
An outage at the Colstrip coal plant in Montana last year was responsible for about half of the higher power supply costs. Avista, which is a part owner of Colstrip, was forced to buy replacement power for about seven months.
A 19 percent increase in electrical demand and opening of the Palouse Wind Farm also added to the utility’s power costs, PUC staff said.
In related news, the PUC is taking comments through Oct. 17 on Avista’s request to lower natural gas rates an average 2.1 percent effective Nov. 1.
If approved, an average-sized residential or small-commercial customer would see a savings of about $1.16 per month.
Colder weather led to more use of natural gas by Avista’s Idaho customers last year, resulting in higher than expected natural gas revenues.