Sierra Club Litigation Leads to Coal Retirement Breakthrough with Ameren Missouri

October 7, 2021: Last month, Ameren Missouri’s latest Integrated Resource Plan (IRP) became effective by order of the Missouri Public Service Commission, establishing a 2028 retirement date for its 1,100 MW Sioux coal plant. The 54 year-old plant, located 20 miles north of downtown St. Louis, emits 4.4 million tons of carbon dioxide per year and its air pollution kills approximately 25 people per year. This is the 346th proposed retirement under the Beyond Coal Campaign.

The IRP also establishes Ameren’s new goal of net zero carbon by 2050 with interim milestones of a 50% reduction by 2030 and 85% by 2040. Additionally, Ameren is planning to add 5,400 MW of clean energy by 2040 with an interim milestone of 3,100 MW by 2030. Sierra Club’s Environmental Law Program litigated the IRP and the related general electric rate case. This is our latest Ameren victory after years of advocacy in multiple venues, from the court of public opinion to judicial courts and numerous rate cases and IRPs.  

The path to this victory on Sioux began with years of advocacy by the Beyond Coal Campaign, the Missouri Chapter, and volunteers and allies. The victory was secured in a settlement negotiated by ELP attorneys between Sierra Club and Ameren in the company’s last rate case in early 2020, in which Ameren agreed to propose retirement of two unspecified coal units by 2028 in its next IRP. Sioux comprises two 550 MW units. In that settlement, we also stopped Ameren’s unfair proposal to increase the fixed monthly charge for residential electric service (which discourages energy efficiency and harms low-income customers) and won a 50% increase in funding for low-income assistance programs.       

Ameren is still one of the largest polluters in the nation, with its Labadie plant being the largest unscrubbed plant in the U.S. With its last triennial IRP in 2017, the company turned a corner on clean energy and with this new IRP, it has slowly accelerated its coal-to-clean transition. The Law Program and Sierra Club generally remain committed to finish the work we are engaged in and assuring a just transition to 100% clean energy in Missouri.