ST. LOUIS — Ameren announced plans Thursday to build a large power plant within the next decade that runs on natural gas — even as the utility aims to accelerate its shift toward carbon neutrality.
The announcement sparked criticism from environmental groups, as well as some skepticism that the plant would come to fruition, mainly due to its presumed costs.
"It's hard for me to believe that it will materialize," said Ashok Gupta, a Kansas City-based energy economist for the Natural Resources Defense Council. "I don't think they will build it or need to build it."
The St. Louis-based electric company outlined broad details about the move in an updated, long-term overview of its power generation plans that the utility files intermittently with state regulators.
Ameren's newly released assessment largely reiterates previous goals, emphasizing robust investment in renewable energy over the next couple of decades, while also aiming to retire three of its four coal-fired power plants by 2030. The document reinforced Ameren's commitment to reducing carbon emissions, and noted its goal to achieve "net zero" emissions by 2045, instead of a prior 2050 target.
One significant change revealed in the plan is Ameren's intention to turn to natural gas amid its long-term shift toward more renewables and less coal. Greenhouse gas emissions from burning natural gas to produce energy are lower than those created by burning coal.
Ameren officials said a gas plant could serve as a "backstop" to balance intermittency of renewable power and ensure reliability as a quickly dispatchable source of electricity.
"We needed more dispatchable resources in our plan," said Mark Birk, chairman and president of Ameren Missouri.
The gas plant would have a capacity of 1,200 megawatts, according to Ameren's plans — slightly greater than that of the Rush Island Energy Center, which is the company's second-biggest coal-fired power plant. Retirement looms for Rush Island amid legal problems and financial strain.
Birk said the new plant will have the ability to use a portion of hydrogen in its mix of fuel and that, "over time, we expect to go to a higher blend of hydrogen." The company also said that it aims to retrofit the plant with carbon capture and storage, to rein in greenhouse gas emissions, "once those technologies become fully mature."
A location for the natural gas plant hasn't been determined, but Ameren officials said they intend for it to be in Missouri.
Uncertainty, opportunity likely with plant closure
Ameren last submitted a full version of its long-term generation plan — or Integrated Resource Plan — in 2020.
Some developments since 2020 helped shape Ameren's new plan in key ways, most notably, the imminent closure of Rush Island.
A proposal to shut down Rush Island earlier than planned, for instance, helped Ameren accelerate its midrange goals for cutting carbon, with the company stating that a 60% cut is now possible by 2030, rather than its earlier aim for a 50% reduction by that time, compared to 2005 levels.
But the upcoming loss of Rush Island has also created uncertainty about how its absence could affect the power grid. Ameren's new plan suggests that the company thinks that a comparably sized gas plant could help address similar, longer-term questions, as coal power continues to exit the grid.
"The main thing is reliability," said Ajay Arora, Ameren Missouri's vice president and chief renewable development officer, explaining the company's planning rationale.
He and Birk said the company does not believe that battery storage technologies, which can be paired with renewables, are mature enough yet, and that natural gas holds more appeal for ensuring reliability.
Critics suggest other avenues for Ameren
Experts and environmental advocates expressed concerns about the new plans.
Some worries center on climate impacts, as the planet-warming risks tied to fossil fuels become steeper and as urgency grows to reduce reliance on them.
Other concerns focus on the prospective price of Ameren's natural gas proposal compared to alternatives that critics said could be more cost-effective.
But some said they take solace in their belief that Ameren's plan is unlikely to materialize.
"They had a hole to fill," said Gupta, with the Natural Resources Defense Council, referring to Rush Island's proposed shutdown. "They needed a placeholder."
Rather than build a new gas plant, Gupta and others pointed out that some appealing alternatives and largely untapped strategies exist.
Widely boosting energy efficiency is seen as an especially crucial front, because it can help dramatically diminish total demand for power, and possibly stave off the need for major new power plants — even as coal-fired ones close.
Gupta said that Ameren could easily achieve energy efficiency savings equivalent to 1,000 megawatts of capacity — an offset that would rival the output of the targeted gas plant and, if realized, could render it unnecessary.
Another environmental group, the Sierra Club, noted that other utilities have charted long-range plans that do not rely on natural gas, and Ameren could do the same.
"We have the tools and solutions right now, and they need to start using them," said Jenn DeRose, a Missouri representative for the Sierra Club's Beyond Coal Campaign. "Other utilities are certainly banking on that."
The group also criticized Ameren's plan to push back the targeted retirement of the Sioux Energy Center — its third-biggest coal plant — from 2028 to 2030.
