Ameren Missouri to add more renewable energy — and fracked gas — in updated plan

Ameren Missouri plans to add more renewable energy and speed its transition to net-zero carbon emissions, the company announced Thursday. But its plan also calls for building a large natural gas power plant in about 10 years. 

The St. Louis-based electric utility filed an updated integrated resource plan with Missouri regulators after a federal judge found in 2019 that Ameren was in violation of the Clean Air Act. The judge ordered Ameren to install pollution controls at one of its coal-fired power plants, the Rush Island Energy Center in Jefferson County. 

Instead, Ameren decided to shutter the plant.

According to the latest plan update, Ameren Missouri will reach net-zero carbon emissions by 2045. Earlier plans had targeted 2050. In an interview, the company’s chairman and president, Mark Birk, said the plan will result in a 60% reduction in carbon emissions by 2030 compared to 2005 levels.

“We want to maintain reliability and resilience and customer affordability, but it also provides emission reductions over the prior plan,” Birk said. 

The plan calls for the Rush Island Energy Center, a 1,178-megawatt plant, to shutter in 2025. 

By 2030, the utility plans to add 3,500 megawatts in wind and solar energy, an increase from the 3,100 megawatts in its previous plan. It has already acquired two wind farms with a combined capacity of 700 megawatts — 20% of the total planned. And it proposes 800 megawatts of battery storage between 2033 and 2038.

However, it plans to delay the closure of the Sioux Energy Center, a 972-megawatt coal-fired power plant in St. Charles County, from 2028 to 2030. And the company plans to build a 1,200 megawatt plant to burn natural, or fracked, gas in 2031. By 2040, it intends to switch that plant to a hydrogen or hydrogen blend fuel and install carbon capture technology.

That proposal drew intense criticism from the Missouri chapter of the Sierra Club, a national environmental nonprofit. 

“Ameren’s decision to illegally operate its Rush Island coal plant in violation of the Clean Air Act…begets another terrible decision, the utility’s new proposal to lock-in the burning of fracked natural gas that is a major cause of our rapidly changing climate,” Jenn DeRose, the Missouri representative for the Sierra Club’s Beyond Coal Campaign, said in a news release. 

DeRose said utilities in Oklahoma and Indiana are retiring coal plants without building new gas facilities.

“Ameren needs to build more renewables and storage, make major investments in energy efficiency and demand response, and close its polluting power plants to preserve human life and prevent the most detrimental impacts of catastrophic climate change,” DeRose said. 

Birk said as the utility adds more renewable energy, it needs sources it can call up on demand, like natural gas.

“We can’t do that with wind and solar. You’re basically taking when the wind blows or the sun shines,” he said. 

Ameren is one of the most coal-reliant utilities in the U.S., said Ashok Gupta, an energy economist for the Natural Resources Defense Council based in Kansas City. In 2021, coal made up more than three-quarters of Ameren’s energy mix. 

The updated plan predicts coal will make up less than half of the company’s energy mix by 2030.

In 2025, it expects to cut its carbon emissions by one-third — about 10 million metric tonnes — compared to its previous plan’s predictions. 

Gupta, like DeRose, didn’t support the addition of a natural gas plant in 2031, but he hopes Ameren will revisit the idea next fall when it files its new plan with more analysis than Thursday’s update. 

He said the update moves Ameren in the right direction. 

“This is my always glass-half-full approach to this, but basically, things are getting better,” Gupta said. “A big coal plant is being retired, a lot more renewables are going to be built, and we get a chance to revisit the gas plant even within a year in terms of when it’s going to be ‘needed.’”

Gupta noted the sort of 20-year plan Ameren updated Thursday is always subject to change. He said he typically focuses on the short-term plans as more likely. 

When he saw Ameren’s plans for carbon sequestration and to switch the proposed natural gas plant to hydrogen after a few years, he said he assumed that was a placeholder. 

“It’s all just words at this point,” Gupta said. 

In the plan, Ameren pushed back some of its renewable energy projects, though it still expects to have more megawatts of renewable energy by 2030.

Ajay Arora, the utility’s chief renewable officer, said the company was factoring in current supply chain challenges and costs. But he said the company doesn’t anticipate any struggle in completing more projects in a compressed number of years. 

Gupta said that would be doable, but not easy for Ameren. 

“I’m starting to call some of this the execution challenge,” he said. “Even after it makes sense and it is modeled and it’s in your plan, you still have to do it. And the ‘do it’ part — it’s hard for everybody.”

Rush Island is a two-unit coal plant situated on the Mississippi River south of St. Louis. Its two units, put into operation in 1976 and 1977, are just old enough they were not required to install pollution controls under a 1977 update to the Clean Air Act requiring newly constructed power plants to install pollution controls. Older coal plants were grandfathered into the rule until they made upgrades beyond routine maintenance in a way that increased emissions.

Ameren overhauled the plant units in 2007 and 2010 and then fell under the requirement but failed to apply for the permit, according to court filings. 

U.S. District Court Judge for the Eastern District of Missouri Rodney Sippel ordered Ameren in 2019 to obtain that permit, install scrubbers and meet standards for sulfur dioxide emissions. In 2021, the 8th Circuit U.S. Court of Appeals upheld that ruling, though it struck down a requirement that Ameren also install scrubbers at the Labadie Energy Center in Franklin County.

Ameren announced late last year that it would retire Rush Island by March 2024 — now 2025 — rather than install pollution controls.

Earlier this month, the Midcontinent Independent Systems Operator, the regional grid Ameren belongs to, said it was worried the closure of Rush Island might cause reliability issues, according to the St. Louis Post-Dispatch. 

In a filing in the federal court case, the Sierra Club criticized Ameren for seeking time to install new power lines to resolve reliability concerns. The filing called the situation “a problem of Ameren’s own making” and noted Ameren can install pollution controls rather than shutter the plant. 

“Ameren attempts to justify its preferred plan by warning that the reliability of the regional grid is at stake if Rush Island stops operating,” the brief says. “Yet, Ameren could keep operating Rush Island by complying with the law and this court’s order — it just does not want to.”