Wisconsin Electric Power (WEPCO) told the Wisconsin Public Service Commission on Oct. 31 that Elm Road Unit 1 was put into “economic shutdown” on Sept. 8, but didn’t offer any more details on why or when the coal-fired unit would be restarted.
The Oct. 31 filing was the latest quarterly report by WEPCO related to two new coal units, called Elm Road, built at the existing Oak Creek coal plant site. In November 2003, the PSC approved the construction of two supercritical pulverized coal units, each sized at 615 MW. Turnover and achievement of commercial operation of Unit 1 (including common systems) and Unit 2 was completed on Feb. 2, 2010, and Jan. 12, 2011, respectively.
With the achievement of commercial operation on both units, construction of the facility is essentially complete. As such, Elm Road Services LLC and Bechtel Power, the engineering, procurement, and construction (EPC) contractor for the facility, are currently focusing on achieving final acceptance of both units, which is not expected to be completed until 2013.
Unit 1 on July 6 experienced a forced draft fan trip due to a plugged filter in the fan inlet, the utility noted. This resulted in the unit being derated to about 50% load. A revised filter design is being pursued. On July 10 the unit experienced a boiler tube leak which forced the unit off‐line. The boiler tube failure was caused by a sootblower not properly retracting from the boiler. The sootblower was repaired and controls were modified so that the operator will be alerted when improper sootblower operation occurs. “On September 8th the unit was placed in economic shutdown,” the utility reported.
Unit 2 on July 2 experienced a fan stall while attempts were being made to correct a calibration discrepancy in the induced draft fan system. The system will be inspected and any issues that are identified will be corrected during a fall planned outage. On Aug. 30 the unit was taken off‐line due to a tube failure. On Sept. 15 the unit’s planned (annual) outage was begun. During the outage, among other things, critical equipment will be inspected to identify any issues prior to the end of the unit warranty period, the utility said, without saying when the unit would be back up.
In the meantime, the Wisconsin Department of Natural Resources went out for public comment Oct. 22 on its preliminary air permit revision approval that would allow WEPCO to burn subbituminous Powder River Basin coal at the Elm Road units. The affected boilers had previously been permitted to burn just bituminous coal.
“These two boilers were only allowed to combust bituminous coal (along with small amounts of natural gas) in the air permit issued 2004,” said a state DNR permit document. “WE is applying to be allowed to burn subbituminous coal either in combination with bituminous coal or as the sole coal combusted in these boilers. The main purpose of this project, as stated by the applicant, is to use lower cost subbituminous coal in the boilers and potentially save WE and ratepayers millions or tens of millions of dollars annually. These savings are realized due to the substantially lower cost on a $/MMBTU basis of subbituminous coal in comparison to bituminous coal.”
WEPCO is a unit of Wisconsin Energy Corp. (NYSE: WEC).