Castle Bluff Energy Center

Reliable Energy When Customers Need It

The Castle Bluff Energy Center will be a reliable backup source of energy ready to use when customers need it most. It’s designed to bolster grid reliability and can be used to deliver energy on the hottest summer days, the coldest winter days or when renewable energy is not generating as forecasted. The site previously hosted similar on-demand generation as part of the Meramec Energy Center. Castle Bluff represents a significant upgrade in reliable backup energy for customers. Construction is subject to approval from the Missouri Public Service Commission.


Digital rendering of Castle Bluff energy center

Economic Development

Developing Castle Bluff will employ hundreds of construction workers, create permanent jobs and provide additional tax revenue for St. Louis County and the surrounding region. Whenever possible, Ameren Missouri hires local contractors, labor, and diverse-owned businesses.


aerial view of the Castle Bluff energy center

Good Neighbors

Ameren Missouri has been a fixture in the community for generations, and we have long-standing, established relationships with our neighbors. Operations at the Castle Bluff Energy Center will be quieter than its predecessor. We anticipate minimal traffic to support operations. Unlike with the Meramec Energy Center, there will be no regular train deliveries or trucks hauling away materials as part of Castle Bluff’s day-to-day operations.


Infographic explaining the projected emissions for Castle Bluff versus the Meramec Energy center. Decrease of carbon dioxide by 40%, decrease of sulfur dioxide by 99%, and decrease of nitrogen oxides by 80%

Environmental Stewardship

Projected emissions, even in the case of increased demand due to extreme temperatures, are far below those of its predecessor. Learn more about how Ameren Missouri plans to provide reliable, affordable and resilient energy to our customers in an environmentally responsible manner at AmerenMissouri.com/Reliable.


Leading the Energy Transition

Ameren is leading the transition to a resilient, clean energy future. As energy demand and extreme weather threats increase, strengthening the energy grid is more important than ever. A stronger, cleaner and more modern energy grid will ensure we can meet today’s challenges and better anticipate those of tomorrow.


Frequently Asked Questions

It's necessary for grid reliability and delivering energy when our customers need it most, especially on the coldest winter mornings and hottest summer days. Castle Bluff is primarily fueled by natural gas, which is a reliable source of energy because it's available 24/7, 365 days a year. It's flexible, always available, and can provide the energy necessary for our customers when renewables are not available due to weather or time of day.

Ameren Missouri customers depend on reliable energy in all seasons and at all times of day. Integrating a new and diverse mix of generation sources while maintaining the availability of our existing energy centers through retirement is essential for a reliable, resilient and affordable clean energy future.

The site was chosen for several reasons, all of which will help keep construction and operation costs down, which translates to lower rates for customers. Ameren Missouri already owns the property. Most importantly, there is existing infrastructure and transmission line access.

On-site construction is scheduled to begin in 2026, and we anticipate Castle Bluff will be ready to serve customers in 2027. The site already has existing infrastructure and transmission line access, reducing overall construction time and cost to customers.

No. Natural gas is naturally odorless. The odor many associate with natural gas is mercaptan, which is added to the gas delivered to your home as a safety precaution. The Castle Bluff Energy Center will not use any mercaptan.

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