Tag Archives: Coal

Coal plant to remain shut for months

The first of two new coal-fired power plants that We Energies opened in Oak Creek (Milwaukee) in recent years will be out of service for several months after an inspection revealed a problem that could lead to turbine corrosion over the long term.

The problem was detected after the plant was taken offline for inspections and maintenance. The plant remains under warranty to the contractor that built it, Bechtel Power Corp.

Utility spokesman Brian Manthey said deposits were found on blades of the coal plant’s steam turbine. Most of the blades that have deposits are being cleaned but some need to be replaced, a process that will take months.

“It’s likely that we will have it back in the spring,” he said.

The second plant, which opened this year, remains in operation, as does the original Oak Creek coal plant, built in the 1950s and 1960s.

The cause of the problem remains under investigation. The problem did not affect operations of the plant, which was online and operating well during the summer heat wave when demand for power was high, he said.

“It’s a precautionary step so that we prevent any long-term damage,” Manthey said.

The utility hasn’t seen any problems of this type on the second coal plant, which opened early this year. The deposits were found as part of an extensive review of the power plant because the plant was nearing the end of its two-year warranty, he said.

“We’ll do the same planned maintenance and inspection toward the end of the warranty period for that unit as well,” Manthey said. “We don’t have any indication that this is happening there.”

As a matter of routine, utilities take plants out of service in the fall to inspect for problems and conduct repairs. This inspection was extensive because the plant is still under warranty and was nearing the February end of the warranty period, Manthey said.

“You want to take care of these thingsnow while it’s still under warraanty,” he said.

The fact that it is still under warranty means that Bechtel or other contractors may have to foot the bill for the problem rather than We Energies and its customers. But that will depend on the investigation into the cause.

“But this is the time to do that, to determine what you’ve got and to see what repairs need to be made and who’s responsible for it,” he said.

The plant experienced some unrelated problems last year during its full first year in operation. Those problems were in a different part of the plant, the boiler feed pump, and have been resolved.

The Oak Creek project was the most expensive construction project in state history, with a total cost of $2.35 billion. We Energies is the primary owner of the plant, along with Madison Gas & Electric Co. of Madison and WPPI Energy of Sun Prairie.

The plants were built to meet demand for rising demand for electricity after Wisconsin experienced power supply problems in the late 1990s.

Construction costs for the project came in higher than the amount approved by the state Public Service Commission, and a proceeding next year concerning We Energies power rates will wrestle with how much of the higher costs should be paid by utility customers.

SOURCE: http://www.jsonline.com/blogs/business/135459568.html

Coal scrubbers are corroding

Ohio pollution controls are showing wear after as little as a year.

Coal-fired power plants across the country are being checked for corrosion problems on billions of dollars’ worth of equipment that is supposed to cut air pollution. And the results from three power companies in Ohio show that the  scrubbers are corroding at a much faster rate than was expected.

Coal scrubbers – some 15 stories tall — spray a slurry of water and limestone into coal flumes to capture most of the pollutants before they’re released into the air. The scrubbers cost up to $500 million, and are supposed to last 25 years.

But Akron-based FirstEnergy discovered corrosion in three new scrubbers at its plant along the Ohio River. None of is older than a year.  American Electric Power also found corrosion at four plants in Ohio and West Virginia. And Duke Energy found it at its Southwest Ohio plant.

A national inquiry is now underway by The Electric Power Research Institute.

John Shingledecker is the senior project manager for the institute. He says he’s seen corrosion in as little as 11 months, and in wide variety of scrubbers.

“There was some initial thought that there was only one particular alloy that was being affected,” he said.

“But there are now different types of alloys, some that have been used in the past as well. And we’ve seen it in multiple designs and multiple manufacturers.”

Shingledecker says figuring out the cause of the corrosion could  take two years, and  in the meantime coal-fired power plants can use protective coatings or clay tiles to try to stop the corrosion.

But American Electric Power spokesman Pat Hemlepp says his company’s scrubbers are operating safely.

”We are working with the industry to address what happening. As far as an environmental standpoint, the equipment does what it’s supposed to do,” he said. “The equipment is taken down for maintenance routinely just like the plants are. And we’re doing whatever is necessary during those maintenance periods to take care of the corrosion issue. It’s not a safety issue, it’s not a health issue.”

Hemlepp says the cost of maintaining the scrubbers has already been calculated into customer bills.

The Columbus Dispatch reported this week that AEP negotiated a confidential settlement with, a contractor on the scrubbers to address corrosion at its central Ohio plants.

SOURCE: http://www.wksu.org/news/story/28895