In its Integrated Resource Plan, the company lays out plans to reduce its carbon dioxide emissions by 30% by 2035. It is looking to achieve this through the phasing out of ageing coal power plants - many of them almost 50 years old - and replacing them with renewable generation.
The majority of this new renewable capacity will come in the form of wind projects of around 400MW, with the rest made up of 45MW of solar, 28MW of hydro and 5MW of landfill gas.
Ameren said that it beeves it can implement these changes without increasing power bills for customers, even though electricity in the state is lower than the average in the midwest of the country.
The firm's plans for carbon dioxide emissions reductions are in line with those proposed in June by the federal Environmental Protection Agency.