The Wisconsin Department of Natural Resources has allowed Wisconsin Power and Light (WPL) to keep using over the long term, without needing an air construction permit, experimental control technologies for mercury and NOx control on the coal-fired Nelson Dewey power plant.
The DNR said in an Aug. 31 letter addressed to WPL that this permitting break covers Units 1 and 2 at the plant. The mercury and NOx control technologies were previously allowed under research and testing exemptions approved by the department. The technologies include the use of activated carbon injection (ACI) and the coal additive CyClean. Based on a review of the information received on Aug 6 from the utility, the project is exempt from the need to obtain a construction permit.
“Based on the test results the overall emissions for Particulate Matter (PM), PM10, and PM2.5 decreased when using ACI and CyClean,” said the letter. Also, mercury emissions were reduced when using ACI and CyClean.
WPL, a subsidiary of Alliant Energy (NYSE:LNT), said July 27 that its energy plans for the future include the purchase of the gas-fired Riverside Energy Center and new emissions controls for the coal-fired Edgewater Unit 5 and Columbia Units 1-2. WPL also said it is planning an orderly retirement of its three oldest and smallest coal units by the end of 2015. They are: Nelson Dewey Units 1-2, located in Cassville, Wisc., which total about 200 MW; and Edgewater Unit 3, located in Sheboygan, Wisc., which is around 60 MW.
WPL will also decide between repowering to natural gas or retiring Edgewater Unit 4 by the end of 2018. It is about 330 MW in size and co-owned with Wisconsin Public Service Corp. WPL said it will work with the Midwest Independent Transmission System Operator to determine the final timing of these retirements and possible fuel switch.