Wisconsin Public Service works toward construction starts on Fox unit upgrades

Wisconsin Public Service Corp. told the Public Service Commission of Wisconsin in an Oct. 30 update that an upgrade project for the gas-fired Fox Energy Center Units 1 and 2 is in its early stages.

In October 2014, the commission approved the Combustion Turbine Technology Conversion Project.

The advanced gas path (turbine section) components, intended for installation on Unit 1 beginning in April 2016, were delivered to the site in September, the utility noted. The DLN 2.6+ combustion system hardware, intended for installation on Unit 1 beginning in April 2016, are scheduled for delivery in January 2016. General Electric International (the contractor) remains on schedule for the procurement of all other materials.

The contractor has completed “requisition” engineering activities related to the hot gas path components, said the utility. The remaining engineering related to the control system upgrade, accessories and the combustion system is expected to be complete in Q4 2015.

The Wisconsin Department of Natural Resources issued an air construction permit on July 21, 2015. A revised construction permit was issued on Sept. 22, 2015, to include the installation of the separate Fox 1–GE Compressor Package 4 project, as both projects are proposed for completion during the planned outage in Q2 2016. The projects were aggregated for the purposes of air permitting.

Construction is projected to begin on Unit 1 on (or about) April 4, 2016. Construction is projected to begin on Unit 2 on (or about) April 3, 2017.

The estimated percentage of completion of physical construction activities is 0%. The anticipated in‐service dates are: Unit 1 – June 1, 2016; and Unit 2 – June 1, 2017.

The estimated cost of the proposed project is $68,076,000, excluding allowance for funds used during construction (AFUDC). As of Sept. 30, actual project costs of $18,494,001 had been incurred, including accruals and excluding AFUDC.

Fox Energy Center Units 1 and 2 are located in the city of Kaukauna, Outagamie County. It is a dual-fuel, combined-cycle generation facility consisting of two GE combustion turbine (CT) generators, arranged in a two-by-two-by-one configuration with two Nooter/Eriksen heat recovery steam generators (HRSG), one Toshiba condensing steam turbine generator, and associated plant equipment. Each CT-generator set includes a GE model 7FB.014 CT, a GE model 7FH2(B)5 hydrogen-cooled generator, and various subsystems. Each CT is capable of operating using either natural gas or No. 2 distillate fuel oil. Because of fuel cost, natural gas is currently used as the primary fuel, with fuel oil used as a backup fuel. Each HRSG is equipped with supplementary natural gas-fired duct burners manufactured by the Coen Co.

The nameplate capacity of the Fox Energy Center is 593 MW, with a summer rating of approximately 550 MW. During summer conditions and when operating at its design point, the net capacity of the combined-cycle facility is approximately 500 MW, with an additional 50 MW of peaking capacity available from operation of duct-firing facilities. The facility is capable of being dispatched from a load level of approximately 150 MW up to its rated capacity.

The ongoing upgrade project consists of the conversion, modification, and upgrade of the “hot section” of each CT from its current configuration, referred to as GE model number 7FB.01, to an advanced technology having a design common to GE 7FA.04 and 7FA.OS models. GE 7FA series turbine models are much more common than those currently in use at the Fox Energy Center, and are better supported by GE.

The project should reduce: turbine firing temperature, pressure ratio, plant heat rate, and air emissions of several pollutants including NOX and carbon monoxide (CO), when the plant is operated above the minimum emissions compliance load. Electrical output will also increase under certain operating conditions. The enhanced design will also improve the durability of hot section components, which will reduce costs related to component repair and replacement.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.