Case Study / Bay City, Michigan
Case Study / Bay City, Michigan
When the Polar Vortex of 2014 swept across North America, it enveloped the Upper Midwest region in a bone-chilling cold that broke records for low temperatures. As the winter wore on, utilities experienced high demand, including power plants serving the Bay City, Michigan area. Complicating the situation was the delay of coal delivery to power plants around the Great Lakes, as carrier ships had to wait for icebreaker vessels to clear a path.
In response, Bay City (Mich.) municipal Electric Light & Power (BCEL&P) had the opportunity to put its Fairbanks Morse engine generators to work to assist in meeting regional power needs. Fueled by natural gas, these engine solutions were called into duty to provide power. While it would seem this was a fortunate coincidence, the fact that these power solutions were installed and ready to serve was the result of thoughtful, long-range planning. By making some wise decisions in the preceding months and years, Bay City Electric Light & Power was in a position to deliver critical power when it was needed most, while helping meet regional power needs and purchase power savings for its customers.
Like other utilities, Bay City maintains a diverse portfolio of power generation facilities. Two of its power plants are each equipped with two Colt Pielstick dual-fuel (diesel fuel and natural gas) gensets from Fairbanks Morse. The four gensets are rated at 27 MW in total and are normally used for peak shaving in the hot summer months when electrical demand spikes.
Recently, Bay City had considered shutting down the two plants, which had been in service for more than two decades. In 2010, an Environmental Protection Agency ruling (commonly known as RICE-NESHAP) called for reduction in emissions of toxic air pollutants and imposed strict operating limits on existing stationary compression-ignition and spark-ignition engines.
To meet these new emissions standards, both of the Bay City plants required modernization, including the addition of diesel oxidation catalysts and silencers. In addition, the gensets were scheduled for a periodic top-end overhaul. The utility’s managers had to make a choice — spend several million dollars to bring the plants into compliance and overhaul the engines, or shut them down completely.
The utility decided to modernize the plants after assessing the power-generation market. Generating capacity was forecast to decline as coal plants shut down, just as power needs were expected to increase as the economy improved and factories ramped up production.
Bay City selected Fairbanks Morse to provide a turnkey overhaul and upgrade program. The cross-functional approach included engine maintenance and installation of all-new engine controls to optimize engine performance, as well as specification and installation of combination catalyst/silencer units.
When the winter of 2013-2014 arrived, Bay City was prepared, although no one quite knew the extent to which utilities would be tested. Adding to the challenge was the common practice of taking plants offline for routine maintenance during these months when electrical demand is typically lower.
And because it had bought natural gas early, Bay City EL&P was able to operate the gensets at a considerably lower cost than if it had to buy gas on the spot market, when prices shot up during the prolonged cold snap.
Although there were no outright power emergencies in Michigan that winter, the Bay City gensets were pressed into service more often during the winter of 2013-2014 than they typically run for peak shaving in summer – helping to maintain stable power costs for customers while ensuring that the lights stayed on through one of the toughest winters in recent memory.
The Colt-Pielstick PC2.6B is a development of the Colt-Pielstick PC2.6 medium-speed engine. While retaining the same main characteristics, the power rating has increased from 615 kW/cyl to 750 kW/cyl. Operating at 600 rpm, this engine features a patented MPC (Modular Pulse Converter) supercharging system while delivering lower fuel consumption. The PC2.6B represents several advantages for power-generation applications including: