Wisconsin Power and Light (WPL), Wisconsin Public Service Corp. and Madison Gas and Electric on Jan. 12 jointly asked the Public Service Commission of Wisconsin for a five-month delay in the construction start deadline for a selective catalytic reduction (SCR) system for NOx control on the coal-fired Columbia Energy Center Unit 2.
The commission approved the project in January 2015, with a Jan. 30, 2016, deadline to begin construction. The unit co-owners now want an extension of that deadline to June 30, 2016.
WPL awarded the Engineering Procurement and Construction (EPC) contract for the project to GSL Columbia SCR Joint Venture on Sept. 1, 2015. The terms of the EPC contract provided GSL 90 days from award to submit the project schedule. WPL has recently received the project schedule from GSL. The first meaningful construction activities in the schedule are to make reinforcements to existing ductwork in preparation for final tie-in of the SCR in 2018. The reinforcements must occur during an outage and GSL plans to carry out the work during the spring 2016 Unit 2 outage. The outage is scheduled from Feb. 27 through April 24. The reinforcement work is expected to begin the first week of March.
On Dec. 23, 2015, WPL submitted a request to the Wisconsin Department of Natural Resources (WDNR) for confirmation of construction permit exemption for the proposed installation of the SCR. WPL is currently waiting on a confirmation response from the WDNR. If the confirmation response is not received prior to the commencement of the spring 2016 Unit 2 outage, the planned reinforcement work may be delayed until the final tie-in outage of the SCR in 2018. In that case, other meaningful construction activities, specifically excavations for foundations, are not scheduled to begin until June 2016.
The companies said the request for extension of the construction start requirement has no effect on the anticipated in-service date for the SCR which remains April 30, 2018.
Columbia Unit 2 consists of a tangentially-fired boiler and steam turbine generator with a nameplate capacity of 511 MW. It is already equipped with low NOx burners and separated overfire air to reduce NOx. Unit 2 is also equipped with a cold-side electrostatic precipitator for particulate control and activated carbon injection to reduce mercury. A dry flue gas desulfurization system, comprised of spray dryer absorbers (SDAs) and a baghouse, were placed in operation in 2014 on Unit 2 to reduce SO2, further reduce particulate matter and reduce acid gas emissions.