Wisconsin Public Service readies for two months of upgrading for Fox Unit 1

Wisconsin Public Service Corp. is securing needed parts and plans to begin an upgrade project on the combustion turbine at Unit 1 of its Fox Energy Center around April 4 of this year, with the upgrade project due to begin in April 2017 on the Unit 2 combustion turbine.

The Public Service Commission of Wisconsin approved this project in October 2014. On Jan. 28, Wisconsin Public Service (WPS) filed an update with the commission on progress so far.

The following major components, intended for installation on Unit 1 beginning in April, have been delivered as of Jan. 25:

  • 7FB.04 Capital Parts, excluding the DLN 2.6+ fuel nozzle assemblies which remain in the manufacturing process (for Q1 2016 delivery);
  • Mark VIe turbine control panel; and
  • 7FB.04 turbine shell.

A factory acceptance test of the new fuel gas module is planned for completion in the first quarter of this year. Contractor General Electric International remains on schedule for the procurement of all other materials. GE has completed “requisition” engineering activities related to the hot gas path, accessories and combustion system components. The remaining engineering related to the control system upgrade is expected to be complete in the first quarter of this year. GE issued a preliminary “field modification instruction” package in the fourth quarter of 2015. A Mark VIe software acceptance test is planned for completion this quarter.

The Wisconsin Department of Natural Resources issued air construction permit in July 2015. A revised construction permit was issued in September 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 the second quarter of 2016 (these projects were aggregated for the purposes of air permitting).

  • Construction is projected to begin on Unit 1 on (or about) April 4, with an in-service date of June 1.
  • Construction is projected to begin on Unit 2 on (or about) April 3, 2017, with an in-service date of June 1, 2017. 

The estimated cost of the project is $68,076,000, excluding allowance for funds used during construction (AFUDC). As of Dec. 31, 2015, actual project costs of $18,589,812 had been incurred, including accruals and excluding AFUDC.

Fox Energy Center Units 1 and 2 are located in Outagamie County, Wisconsin. It is a dual-fuel, combined-cycle facility consisting of two GE combustion turbines (CTs), 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.

The planned 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 Fox plant, 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, 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.