Wisconsin Power and Light told the Public Service Commission of Wisconsin in a Jan. 28 project update that work is still ongoing ahead of a construction start for a selective catalytic reduction (SCR) system to control NOx emissions from the coal-fired Columbia Energy Center Unit 2.
Wisconsin Power and Light (WPL), Wisconsin Public Service Corp. and Madison Gas and Electric were approved in January 2015 by the commission to install this SCR on their co-owned unit. To comply with that order, construction was to commence no later than Jan. 30, 2016. On Jan. 12, WPL filed a request with the commission for a five-month extension on that deadline, to June 30. On Jan. 22, the commission granted the requested extension.
The estimated cost of the approved project was $150 million, excluding AFUDC. After signing a contract and confirming pricing for the Engineer Procurement Construction (EPC) services, the project forecast has been revised to $110 million.
Construction activities have not commenced, the Jan. 28 update noted. In September 2015, WPL signed a contract with GSL Columbia SCR Joint Venture for the EPC services. GSL is a joint venture between Graycor Industrial Constructors and Sargent & Lundy LLC. GSL subcontracted the SCR technology supply to Andritz Inc.
The anticipated in-service date for the SCR currently is April 30, 2018.
On Dec. 23, 2015, WPL filed a request for confirmation of air construction permit exemption with the Wisconsin Department of Natural Resources (WDNR). On Jan. 20, WPL received confirmation of the permit exemption from the WDNR.
Engineering activities were executed during the period of this report to support the project schedule. Primary activities included:
- Conducting various studies and reports required by the EPC contract
- Layout and design of SCR box, ductwork, and structural steel
- Development of the not to exceed loading diagram and foundation design
- Development of the 3D mode
GSL is preparing to perform work during a 2016 unit outage. The work consists of making reinforcements to existing ductwork in preparation for final tie-in of the SCR in 2018. GSL is also preparing for full mobilization during the second quarter of 2016. Other construction activities, specifically excavations for foundations, are scheduled to begin in June.
The Columbia Energy Center is located south of Portage, Wisconsin, along the Wisconsin River. The facility consists of two coal-fired units, designated as Units 1 and 2. These units began operation in 1975 and 1978, and have nameplate generation capacities of 512 MW and 511 MW, respectively. The three utilities jointly own both units. Both units currently utilize sub-bituminous Powder River Basin coal obtained from various mines.
WPL, by the way, filed a separate update with the commission on Jan. 28 over a largely-completed Emission Reduction Project for Columbia Energy Center Units 1 and 2. This is known as the Air Quality Control System (AQCS) project.
“Despite having continuing issues with atomizer vibration and other material handling sub-systems, the AQCS systems have performed well,” the utility said. “Sulfur dioxide and mercury emissions for 2015 were well under the required limits. The redundancy designed into the systems allowed the AQCS to run at 100% reliability for all of 2015 (no derates or shutdowns associated with the AQCS). This report will only cover the status of the remaining punch list items. The project has been completed at $588,676,208, which includes the cost of remaining items estimated at $2,265,352. This is approximately one million dollars less than reported in the last report and is the result of lower cost solutions than originally anticipated.
“All of the remaining items are in-progress and the cost estimates are representative of the materials and work being performed. Unfortunately, some of the remaining work requires unit outages to complete and/or long lead times for delivery. The work to address the ice formations from forming at the top of each chimney will occur during the upcoming unit outages (the outage for Unit 1 started on January 16th and the Unit 2 outage is scheduled to begin on February 27th). Also, the lift oil systems for the four AQCS booster fans will be completed during these outages. The third spare atomizer has been ordered and is being manufactured. It is not expected to be on-site until the July/August timeframe.”