Wisconsin municipal looking to save 7.6 MW of diesel-fired capacity

Fennimore Electric Utility on Oct. 23 filed a revised application with the Public Service Commission of Wisconsin for approval to install new equipment on five small diesel generators with a total of about 7.6 MW of capacity.

The project is to replace the aging exhaust systems that were installed in 1999 with new critical grade silencers and related equipment that includes diesel oxidation catalysts that will be optimized for Fennimore’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 NESHAP.

The proposed new facilities will be warranted by the supplying vendor/contractor to meet current EPA NESHAP requirements and will be expandable to meet future emission requirements. The proposed replacement silencers will be located in the exact positions as the ones removed. The proposed replacement silencers are a combination unit, containing catalytic units, which will be accessible from the outside for cleaning and replacement. 

The approximate construction schedule is to start before Dec. 31, 2015, with completion by May 1, 2016. The gross cost of the project is estimated to be $425,000. Financing of the project is expected to be from internal funds.

The completion of this project will bring Fennimore’s generation into full compliance with EPA NESHAP requirements and allow Fennimore to continue to meet the bulk of its resource adequacy obligations required by the commission. The impact on Fennimore’s cost of operations associated with this project is projected to be a significant decrease over time. The alternative to this project would be to abandon the generation plant and purchase the needed capacity. The 20-year nominal purchased cost of the required capacity is estimated to be about $12.0 million (or about $6.72 million on a net present value basis) if the remaining un-depreciated balance of the abandoned generating plant is ignored.

The Fennimore Electric Utility has local generation that consists of five units ranging in size from 968 kW up to 1,825 kW of nameplate capacity. Although some units may be fueled by gas or diesel, they are all predominately fired using diesel fuel. For the past few years, in accordance with Fennimore’s wholesale power contract with Dairyland Power Cooperative (DPC), these units have been registered by DPC in the Demand Response Program of the Midcontinent Independent Transmission System Operator as emergency generators, meaning they can be called upon by MISO or by DPC (as the applicable Local Balancing Authority) to respond to Level 2 system-wide emergencies. Under MISO tariff rules, the units are also eligible to be counted as capacity resources, enabling Fennimore to meet its resource adequacy obligations.

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.