Serine
Ameren Missouri has announced its intention to build the Big Hollow Energy Center, a dual-component energy facility that will include an 800-MW simple-cycle natural gas plant and a 400-MW lithium-ion battery storage system in Jefferson County.
This will be Ameren’s first large-scale battery storage installation, designed to meet growing electricity demands while strengthening grid reliability.
Expected to go live by 2028, pending regulatory approvals, the project marks a significant step in Ameren’s long-term energy strategy. The utility aims to deploy 1 GW of energy storage by 2030 and 1.8 GW by 2042.
Balancing Generation for Grid Resilience
According to Ameren Missouri, the Big Hollow Energy Center is intended to “efficiently address rising energy needs while supporting a resilient power grid.”
The battery and gas units will operate independently, with construction taking place on existing Ameren-owned land to reduce costs and speed up timelines.
Ajay Arora, senior vice president and chief development officer at Ameren Missouri, emphasized the importance of diversified energy generation:
“Having a balanced energy mix and strategically locating assets across the region is key to optimizing energy output.”
Part of Ameren’s Long-Term Expansion Plan
In February 2025, Ameren revised its Integrated Resource Plan to accommodate a projected 1.5 GW rise in electricity demand by 2032.
By 2030, the company plans to add 1.6 GW of gas-fired generation, with a cumulative expansion of 6.1 GW by 2045.
Ameren’s growing infrastructure aims to support a surge in economic development. The utility reported that nearly two dozen new industrial projects were launched in 2024, and it has since established construction agreements with additional high-load customers.
Smart Energy Plan: Investing in the Future
Alongside its generation projects, Ameren also submitted an updated Smart Energy Plan to the Missouri Public Service Commission earlier this year.
The $16.2 billion five-year proposal focuses on grid modernization, aiming to enhance reliability, resilience, and system performance across the state.
Mark Birk, President and Chairman of Ameren Missouri, noted:
“This initiative is the next step in delivering on our commitment to modernize infrastructure and provide a balanced, reliable energy portfolio for our customers.”
With the launch of the Big Hollow Energy Center, Ameren Missouri is setting the stage for a more robust and sustainable power system.
By integrating natural gas and large-scale battery storage, the utility reinforces its commitment to balancing energy reliability, cost-efficiency, and future demand—laying the foundation for Missouri’s energy future.