BOISE - Idaho Power today filed an application with the Idaho Public Utilities Commission to increase the company's base rates for electricity an average of 9.9 percent for its Idaho customers, the company announced Friday.

Although the requested increase is for an average of 9.9 percent, the company's rate proposal impacts various customer groups differently, officials say.

For example, if the request is approved as filed, residential customers would see an average increase of 6.3 percent.

The monthly bill for a typical residential customer using 1,050 kilowatt-hours (kWh) per month would increase from $66.06 to $69.83 during non-summer months and from $70.21 to $74.86 per month during June, July and August.

"Two forces are driving this increase; growth in the number of customers and a growing demand for electricity," said Ric Gale, Idaho Power vice president for regulatory affairs. "We have invested heavily to ensure we can provide a safe and dependable supply of energy for our current and future customers. This request seeks to recover those investments."

Although Idaho Power is seeking an average increase of 9.9 percent to its base rates, the rates and overall percentage increases differ among customer groups because the costs of serving different customer groups vary.

Costs vary due to differences in the way customer groups receive and use electricity. Idaho Power's specific rate proposals for customer groups seek to align more closely customers' rates with the costs of providing them electrical service.