The federal agency, the Bonneville Power Administration, announced its intention to raise wholesale power rates to its utility customers in two ways. First it has adopted a 9 percent average wholesale power rate increase and an 11 percent average transmission rate increase. These rate  increases to utilities such as Puget Sound Energy, will in part, be passed through to customers in retail electricity rates.

The transmission rate is the amount of money charged to utilities for the use of the agency’s high voltage transmission system.

The new rates take effect Oct. 1, 2013.

For Bonneville’s utility power customers, the wholesale power rate increase will be an average of 9 percent higher than current rates. The power rate increase stems from higher costs to operate and maintain the federal hydroelectric system, and to fund existing long-term agreements for the fish and wildlife mitigation program and reduced revenues from surplus power sales due to low market prices.

An average of $20 million per year in financial reserves will be used to offset part of the rate increase.