RPU study: Lean, clean electricity

Plan calls for retirement of dirty, old generators


A story on Page 1B Wednesday about a Rochester Public Utilities power study erroneously referred to a cap on annual rate increases. The RPU board did not authorize or consider a rate cap. The utility would also spend $23.8 million to install pollution controls at the Silver Lake Power Plant and up to $6 million to optimize combustion in the Unit 3 generator. Unspecified amounts would be used elsewhere, such as to replace two other coal-burning generators and to promote energy conservation practices.


By Jeffrey Pieters


A two-year study by Rochester Public Utilities of ways to meet growing local electrical power needs while cleaning up emissions from the Silver Lake Power Plant ended with a $23 million solution.

It brought smiles to the faces of local environmentalists. Its pairing with a cap on annual rate increases might keep local rate-payers happy as well.

RPU's plan, adopted 4-0 by the utility board on Tuesday, calls for spending an estimated $23.8 million on new emissions controls at the coal-fired plant, while holding annual rate increases to an average of 2 percent during the next 30 years.

The controls will reduce emissions of certain pollutants by as much as tenfold –; even as the utility doubles power production at the Silver Lake plant. The proposal was also shown to have the lowest long-term cost of three alternatives the board considered.

"This is proven technology that is going to result in significant (pollution) reductions," said RPU General Manager Larry Koshire. "We think it's the right thing to do, and the study shows it's the economical thing to do."

Under pressure from local environmental groups, the RPU board ordered the study in May 2003.

Within the next decade, RPU will retire the two oldest generators at the Silver Lake plant, fine-tune combustion in Unit 3 to reduce emissions, and install pollution controls on Unit 4, a 55-megawatt generator that accounts for more than half of the capacity of the plant.


The controls would "far exceed" what's needed to meet foreseen state and federal emissions requirements, said Wally Schlink, the utility's director of power resources.

The controls would reduce Unit 4's sulfur dioxide emissions from 1,787 tons per year to 155 tons, and nitrogen oxide emissions from 368 tons per year to 136 tons, Schlink said. They would hold the line on particulate and mercury emissions, all while the plant's coal consumption is forecast to rise from 85,000 tons of coal per year -- the 1999-2000 level -- to 170,000 tons.

Meanwhile, RPU would replace the retired coal-burners with cleaner, natural-gas-burning generators.

Holding down power demand is a critical part of RPU's plan. A practice known as "demand-side management" has the utility working with customers to encourage conservation.

The practice already seems to be working, Koshire said. Despite a recent string of 90-degree days, Rochester still has not topped its record peak demand of 262 megawatts, set in 2003. This year's peak so far is 256 megawatts, despite the fact Rochester has hundreds more homes than it had two years ago.

"Personally, I'm tickled," said Norm Erickson, one of several local environmentalists who pushed RPU to begin the study, then worked with the utility on it.

"The bar is swinging in the direction of the environment and energy conservation," he said

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