Ameren Missouri CTGs played a critical role during summer heat wave

Natural gas power plants helped meet demand during hot July weather

Ameren Missouri relies on a balanced mix of energy generation to serve its customers. Baseload energy from coal-fired facilities and nuclear power from the Callaway Energy Center do much of the heavy lifting, while other generation sources, including hydropower, make up the company's generation fleet. On a typical day with comfortable temperatures, this mix of generation is often enough to meet the energy needs of the company's customers.

When that mix of energy generation isn't enough, combustion turbine generators (CTGs) are often utilized to ensure there is enough energy to meet demand. Often referred to as on-demand plants, these units can start up quickly and support grid reliability during the hottest of summer days or coldest of winter nights.

"These generators play an important role in Ameren Missouri’s energy mix, especially during stretches of extreme heat,” said Jeff Moore, director of renewables and CTG operations for Ameren Missouri. “These units can also serve as a critical backup to meet system demand when electric load is high or when renewables are not available.”

Located in Bowling Green, the Peno Creek Energy Center is part of the company's fleet of CTGs.

Ameren Missouri maintains a fleet of 40 CTG units across nearly a dozen energy centers in Missouri and Illinois. They run primarily on natural gas, with some units outfitted to use fuel oil. Together, these units can produce up to 2,750 megawatts (MW) of energy. That’s a welcome boost to the grid when temperatures soar in summer or sink below freezing in winter.

Teams work year-round to keep these CTG units ready for use. This work proved key during a record-hot month of July, when Ameren Missouri logged more than 500 engine starts and set a record for consecutive days of natural gas generation. On days when the local and regional grid were working hard to meet demand, Ameren Missouri's CTG fleet helped keep the grid reliable so people could stay safe and cool. 

To support the needs of their customers, both residential and business, Ameren Missouri is investing in additional natural gas generation. Work is underway on the Castle Bluff Energy Center in south St. Louis County, an 800-MW, four-unit CTG at the former site of the Meramec Energy Center. A second 800-MW facility, known as Big Hollow Energy Center, is planned for Jefferson County and will include an additional 400 MW of battery storage. The company is also investing in a fuel oil backup for its CTG units in Audrain County, allowing the units to operate more effectively in extreme cold conditions.