Upper Michigan Energy Resources Corp. (UMERC) placed two new natural gas-fired generating stations into commercial operation on March 31, part of the company’s plan to reshape its generation fleet as it seeks to “balance reliability and customer cost with environmental stewardship.”
UMERC, a subsidiary of WEC Energy Group, also retired the coal-fired 430-MW Presque Isle Power Plant on Sunday. The company in a news release said, “Plans for the future use of the retired coal plant site will be developed as the company continues to evaluate potential uses for the property.”
“The new generating stations are good for our customers, good for business and good for electric reliability throughout the U.P.,” said Kevin Fletcher, president and CEO of WEC Energy Group, in a news release. “Closure of the Presque Isle Power Plant also helps achieve our goal of reducing carbon dioxide emissions by 40 percent, well ahead of our 2030 target.”
The new F.D. Kuester Generating Station, in Negaunee Township near Marquette, and the A.J. Mihm Generating Station, near L’Anse in Baraga Township, are both in Michigan’s Upper Peninsula. The stations, which represent a $275 million investment by WEC, use a technology known as RICE—reciprocating internal combustion engines. RICE systems are touted for their high efficiency, modular construction, and operational flexibility.
The 128.1-MW (net generating capacity) Kuester station includes seven RICE units, and the 54.9-MW (net) Mihm station has three. Each engine is a Wartsila 18V560SG model, shaft-coupled to an electric generator, with gross generation capacity of 18.9 MW.
The RICE units are inside a warehouse-type building, with the exhaust system located outside the building. The exhaust system includes silencers, air quality control systems, and stacks. The seven engines at Kuester are ducted to a single, common 130-foot stack. Each of the three engines at Mihm has its own 65-foot stack. The stations each use selective catalytic reduction with urea injection to control emissions.
UMERC said it worked with the engine manufacturer and an engineering firm to design each generating station with a 50-decibel sound limit, “similar to the sound made by a household floor fan.” Testing of the units prior to commercial operation indicated the stations each operate between 25 and 36 decibels. Sound-dampening features include concrete walls with interior sound attenuation panels, a double-layer roof, the use of heavy-duty steel panels with sound attenuation, silencers on air intake and exhaust systems, and ultra-low-noise radiators.
Each power plant is controlled and monitored remotely by operators in Green Bay and Milwaukee, Wisconsin, according to UMERC. “Local, plant-based computer controls support the operation by continuously monitoring and reporting ignition conditions, pressures, temperatures, flow rates, etc.,” the company said in a news release. “Both facilities employ total remote start, stop and loading functionality, with on-site personnel focused on maintenance and support activities.”
UMERC said plans for the transition away from coal to natural gas began in 2015, when then-governor Rick Snyder said new energy sources were needed in the U.P. The new stations are designed to eliminate the need for more transmission capacity in the region. They also saved the utility from making upgrades to the Presque Isle plant. UMERC said the new gas-fired stations should save customers about $600 million over the next 30 years.
WEC Energy Group funded the $275 million investment. It said half the investment will be recovered through a 20-year power purchase agreement with Cliffs Natural Resources, a mining company. The other half will be recovered in retail electric rates.
Another retired coal plant in the U.P. is scheduled for demolition this year. The 44-MW Shiras Steam Plant, which served the Marquette area for more than 50 years, was shut down in June 2018. The Marquette Board of Light and Power, a city-owned utility, last week said the land where the plant sits along Lake Superior will be repurposed for community uses.
Marquette is now served by the gas-fired 50-MW Marquette Energy Center, which uses three Wartsila RICE units.
—Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWERmagazine).