Salt River Project’s board of directors has approved changes to the utility’s Fuel and Purchased Power Adjustment Factor in a response to what it classifies as undercollected fuel and purchased-power expenses.

The changes will increase the overall average annual bill of Kyrene Corridor and other SRP residential electric customers by 5.1 percent starting with bills issued on or after Nov. 1.

According to SRP, the higher costs are primarily due to higher natural gas and wholesale electric prices during the first half of this year. 

During the first quarter of this fiscal year, the fuel cost of SRP’s natural gas-fired generating resources serving retail customers increased by 17 percent over the same three-month period of 2007, according to a report.

For a typical SRP residential customer using 960 kilowatt-hours per month during the winter, the adjustment will result in an average monthly increase of $4.70 per month. The typical customer using 1,610 kWh per month during the summer will experience an increase of $7.89 per month during those higher-temperature months.

Even with the current increase SRP’s prices remain among the lowest in the Southwest, according to SRP officials.