In its final integrated resource plan, a road map of how the company wants to operate by 2020, PSE said it would maintain its reliance on Colstrip.
“Overall, the analysis found that Colstrip reduces cost and market risk for our customers,” PSE said in a statement.
“Three key risk factors have the greatest effect on Colstrip’s performance as an economic, least-cost resource: very high CO2 costs, very high disposal costs for coal combustion residuals and very low natural gas prices for a very long time.
“At this time, the analysis indicates that continuing current operations at Colstrip saves PSE customers about $150 million per year.
“Put a different way, replacing Colstrip with another resource would result in approximately a 7% annual rate increase, apart from any other rate pressures.”
PSE is the largest owner of the 2094-megawatt Montana plant which comprises four units built between 1975 and 1986.
Western Energy Company provides coal for the plant.
PSE said since 2000 the six Colstrip owners spent $97 million to control ash pond leakage, reduce migration of affected groundwater and to upgrade plant wastewater systems to allow increased recycling of water.
“There is long-term uncertainty for coal generation in general but Colstrip reduces cost and market risk in most scenarios,” the utility said in its report.
The Sierra Club and other environmental groups in Washington have long opposed the utility’s use of coal-fired power and staged a press conference and demonstration just outside Seattle on Thursday to coincide with the release of PSE’s report.
“While PSE supports many clean-energy programs, it also owns the largest, most polluting coal-fired power plant in the northwest,” Sierra Club Washington representative Doug Howell said in a statement.
The groups barged an inflatable coal plant in the waters off Mercer Island, just outside Seattle, surrounded with “clean energy kayaks” to encourage PSE to step away from coal use.
A public comment process commenced today with the release of the utility’s plan and the Sierra Club said it had written a letter to the utility expressing its opposition.