Pasadena Decides to Overhaul Old Power Plant to Save Money : Utilities: Refurbishing a 35-year-old steam generator will cost the city at least $28 million less than building a new facility.

The Water and Power Department has discovered what a number of utilities have learned: It’s cheaper and faster to rebuild than to replace.

The department is in the midst of a 10-year, $11.6-million project to completely overhaul the 35-year-old Unit B-1 steam generator, one of three at the Broadway Steam Plant next to the Pasadena Freeway on Glenarm Street.

The B-1 unit, built in 1955, was scheduled to be shut down this year. But Pasadena has decided instead to keep it going for 25 more years.

For seven months last year, city workers shut down the unit to assess how much work needed to be done. They climbed through manholes at the top of the 90-foot boiler and into spaces normally filled with a seven-story column of 2,800-degree flame.

They inspected hundreds of tubes where 9,000 gallons of purified water turn to steam, moving giant turbine blades and generating 44,000 kilowatts of electricity.

“It feels like large pipe organs all around you,” said Gerald Gough, the city’s power production supervisor and one of the workers to get a rare glimpse of the inner workings of the machinery.

As a result of the inspections, the city concluded, in a report released in August, that a new steam plant would have cost the city up to $70.4 million and that a new gas turbine plant would have cost up to $39.6 million, while rebuilding will come to only $11.6 million.

In addition, upgrading the B-1 unit will ensure low electric rates for Pasadena residents. Keeping the unit operating in combination with the city’s other generators enables the utility to supply all the city’s electric needs and buy cheaper energy from outside suppliers when available.

“We’ve got a huge capital investment here,” Gough said of the old plant. “If you take care of your resources, like an older building or older car, it can offer you a lot more life.”

The same philosophy, coupled with stricter air pollution and environmental controls, has prompted other utilities to do the same. The Los Angeles Department of Water and Power will soon begin revamping its five steam turbine generators at the Harbor Generating Station in Wilmington.

“It’s the oldest and least efficient facility in our system,” utility spokeswoman Mindy Berman said. Some of the Wilmington units date to the 1940s and the plant is used only sporadically to cover peak electricity demand, she said.

Under Los Angeles’ $150-million repowering plan, to be completed in 1993, two natural gas turbines will be installed to replace the five existing fuel oil-burning steam generators. Three of the generators will be modified to generate power from waste heat given off by the two gas turbines.

“There will be a tremendous increase in efficiency, it will burn a lot less fuel and there will be fewer emissions,” project manager John Schuman said.

Similarly, Southern California Edison is studying a proposal to rehabilitate older units in San Bernardino, Redondo Beach, Huntington Beach and Alameda, now used only during periods of peak electricity demand.

But the idea is not new, said Fred Mobasheri, Edison’s resource planning manager. Edison rehabilitated its Long Beach plant in 1976, he said.

“It’s a trend now that the (electrical) demand is growing,” Mobasheri said. Many utilities were over capacity for years, he said, but now their units are becoming old and less cost efficient to run. Repowering and refurbishing old plants is being done increasingly “rather than going around and building new plants at new sites,” he said.

Besides saving the cost of installing new transmission lines, substations and roads at new sites, rehabilitation has the added advantage of saving time, said Nancy Montgomery of the Edison Electric Institute, a Washington lobbying association of 200 investor-owned utility companies.

Two companies, General Electric and ABB, a European firm, supply combustion turbines, she said. As a result, the wait for the new units has grown from 12 months to up to three years.

In addition, new sites mean new construction and environmental approvals, a process that can take up to eight years, Montgomery said.

For Pasadena, rehabilitation of the B-1 unit will take 10 years, but it will be done with only occasional shutdowns and with incremental financing from the city’s capital expenditure budget, Gough said.

“The old way of doing things was to shut it down, do the major modifications and plunk down a lot of money,” he said. “This is a much more sane approach.”

The work includes replacement of turbine blades, replacement of the cooling tower, cleaning and recoating structural steel, overhauling the boiler pump, cleaning corrosion from water lines, and a host of other technical jobs, large and small.

The city originally planned to start phasing out steam units at the Broadway Steam Plant when nuclear and coal energy were cheap, said Henry Lee, assistant general manager for power systems. But by the early 1980s, construction costs for new plants had risen to $1,600 per kilowatt of generating capacity, compared to $264 per kilowatt to revamp the plant for another 20 to 25 years of operation.

So, in 1988, the Pasadena Board of Directors approved the rehabilitation plan the department is now pursuing. The city is also studying whether one unit at the nearby Glenarm Steam Plant, whose two units were retired in 1984, can be rehabilitated in a similar fashion and placed back in service, Lee said.

But how much longer the B-1 unit and others can be maintained once they have been overhauled, no one knows. After the 25 additional years have passed with the B-1 unit, the city could probably obtain more years of service “but probably not another 25 years because of metal fatigue,” Lee said.

“What we’re entering into is a phase called life cycle management,” Gough said. “You manage the life of the various components and you keep checking to determine how much life there is. This is a continuing process.”