Ameren plans to build a natural gas-fired power plant in south St. Louis County on the former site of its oldest and smallest coal plant, which closed a year ago, the company announced Thursday.
The St. Louis-based electric utility said the new facility would be used as a “peaker” plant to bolster power reliability when demand is greatest — like the hottest or coldest extremes of summer and winter — and that it could cost about $800 million.
The gas-powered plant would be called the Castle Bluff Energy Center, and sit at the confluence of the Meramec and Mississippi rivers, next to where the former Meramec Energy Center burned coal for decades. The company said its old Meramec site is an inviting and cost-effective location for the proposed 800-megawatt project because it already offers coveted and readymade attributes, like electric transmission access and interconnection to an existing gas pipeline.
The proposed move will require approval from the electric monopoly’s state regulators and is sure to be met with questions, given the financial impact it would have on the company’s ratepayers, compared to potential alternatives.
Some skeptics have already raised those questions about what they see as a hefty and “risky” bet on natural gas.
“There are cheaper options,” said Ashok Gupta, a Kansas City-based energy economist for the Natural Resources Defense Council. “Some of us believe that the better option in the near term is: Invest in more efficiency, instead.”
He estimated, for instance, that Ameren could reduce the region’s peak power demand by 10% to 30%, if more money is poured into boosting energy efficiency — something that might help customers dodge large expenditures on new power plants.
“You have to look at the cost of efficiency versus the cost of a new gas plant,” said Gupta. “This is giving us the opportunity to make the case for efficiency. There’s still a lot of questions that have to be answered before it is approved and built.”
Ameren, though, says the new plant is essential to complement — and enable — its extensive buildout of renewable energy projects planned over the next two decades, and will help provide the utility with reliable power to balance the intermittency of wind or solar energy.
“This is meant to facilitate our transition to renewable energy,” said Jeff Moore, Ameren’s director of “combustion-turbine-generator” power plants. “That is our No. 1 goal. … Reliable power at all times, and all seasons.”
The local chapter of the Sierra Club called for Ameren to offer “radical transparency” to justify its push for the plant.
“This raises a lot of questions that I doubt Ameren has answered and that its customers deserve, especially after the utility illegally emitted sulfur dioxide from Rush Island for more than a decade,” said Ed Smith, a spokesman for the Sierra Club, referring to long-running Clean Air Act violations at Ameren’s Jefferson County coal plant.
The group also challenged Ameren’s choice to invest in a new plant that burns fossil fuels, given widely recognized urgency to slash greenhouse gas emissions, and the utility’s own corporate goals to reach “net zero” carbon emissions by 2045.
