During Winter Storm Fern, Ameren Illinois’ natural gas storage system helped protect customers from extreme wholesale market price spikes that impacted other regions.

The company says natural gas storage played a critical role in keeping homes heated, businesses operating, and communities safe during the severe winter weather. Ameren Illinois officials say customers benefited from the company’s storage capabilities and recent improvements made to strengthen underground storage fields.

As national natural gas prices surged to as high as $70 per million British thermal units during the storm, Ameren Illinois was able to deliver gas it purchased during the summer months at prices between $3 and $4 per million British thermal units. The company says that strategy protected customers from price volatility in the energy sector from January 23 through February 2, 2026.
Through optimized storage operations, leased storage, and strategic hedging, Ameren Illinois estimates it and its customers avoided $78.2 million in market exposure during the severe weather event.

Ameren Illinois also reports its natural gas system performed at peak efficiency throughout the cold snap. From January 23 through January 29, the storage system operated without outages or performance issues, despite sustained subzero temperatures and heavy demand.

January 23 ranked as the 14th highest natural gas usage day on record for Ameren Illinois customers. Over the six-day period, 2.46 billion cubic feet of natural gas were withdrawn from storage, accounting for more than 10 percent of the company’s total gas inventory for the winter heating season.

Company officials say the performance of underground storage and price hedging during Winter Storm Fern demonstrates the value of long-term planning and investment in energy infrastructure during extreme weather events.