Elroy Electric Utility applied Nov. 4 at the Public Service Commission of Wisconsin for approval of retrofits on three diesel-fired generators with a total of 6.57 MW of capacity, with those units to be shut without these installations.
The project is to replace the aging exhaust system that was installed in the 1973-2005 period with new critical grade silencers and related equipment that includes diesel oxidation catalysts that will be optimized for Elroy’s generating units. It will also include a crankcase ventilation system (CVS) plus a continuous monitoring system. The proposed equipment will control and reduce carbon monoxide (CO) emissions by 70%, and control emissions of total hydrocarbons, PM10, PM2.5 and odor causing compounds and will include the required continuous catalyst temperature monitoring system as required by the U.S. EPA’s National Emissions Standards for Hazardous Air Pollutants (NESHAP) program.
The proposed replacement silencer is a combination unit, containing catalytic units, which will be accessible from the outside for cleaning and replacement. The silencer will be of a critical grade, and will provide a higher degree of noise control than the existing deteriorated silencers.
The approximate construction schedule is to start by Dec. 31, 2015, with completion by April 1, 2016. The gross cost of the project is estimated to be $220,000. Financing of the project is expected to be from internal funds.
Elroy staff has determined that the only alternatives are to: upgrade the generation facilities as proposed; or abandon these generation facilities and purchase all replacement capacity from Dairyland Power Cooperative (DPC) or an alternate provider, per contract obligations. Although the current market cost of capacity is low, future capacity pricing data provided by DPC as well as the Midcontinent ISO’s current CONE (Cost of New Entry) prices clearly suggest that Elroy’s reliance on capacity purchases could be a very expensive option over time, the municipal utiity said.