Duke Energy's Limestone Conversion Project Faces Scrutiny

The Kentucky Public Service Commission has initiated a proceeding to consider Duke Energy Kentucky, Inc.'s application for a certificate of public convenience and necessity to convert its wet flue gas desulfurization system from a quicklime reagent process to a limestone reagent handling system at its East Bend Generating Station. Environmental groups, including the Sierra Club, have expressed concerns about the project's justification and costs.

Key Takeaways:

• The Sierra Club's Dr. Ranajit Sahu submitted testimony on March 28, 2025, expressing concerns about Duke Energy's reliance on MATS compliance to justify the $125.8 million limestone conversion project.
• Dr. Sahu pointed out that East Bend Generating Station was not on the EPA's list of electric generating units that would need to upgrade emissions controls to meet the May 2024 MATS limits.
• The EPA announced on March 12, 2025, that it would reconsider the MATS rule and extend compliance timelines while the rulemaking process is underway.
• The EPA estimated that the MATS rule would cost over $790 million over the next decade, starting in 2028, with at least $92 million per year for the power sector.
• Upon the EPA's announcement, the Company's MEL provider offered new contract terms that would lower the cost and extend the duration of the contract for the MEL reagent.
• Dr. Sahu recommended that the Commission deny Duke's request for a CPCN and require the Company to fully evaluate reasonable alternatives to the limestone conversion project.

Statistics:

• The estimated cost of the MATS rule is over $790 million over the next decade, starting in 2028.
• The estimated annual cost of the MATS rule for the power sector is at least $92 million.
• The deadline for compliance with the MATS rule is July 2027.