Louisville Gas & Electric Company Seeks Permit for New 680 MW Natural Gas-Fired Combined Cycle Unit 6

Strategic Insights -

The Louisville Gas & Electric Company (LG&E) is submitting an air permit application to the Kentucky Public Service Commission to install a new 680 MW natural gas-fired combined cycle electric generating unit, Unit 6, at the Mill Creek Generating Station in Jefferson County, Kentucky. The proposed unit will be equipped with state-of-the-art technology, including dry-low-NOX combustors, low-NOX duct burners, oxidation catalysts, and selective catalytic reduction systems to minimize emissions of regulated pollutants such as NOX, CO, hydrocarbons, and organic hazardous air pollutants.

Key Takeaways:

  • The proposed Unit 6 will be a 680 MW natural gas-fired combined cycle electric generating unit, with a gas turbine, steam turbine, and heat recovery steam generator.
  • The unit will utilize dry-low-NOX combustors, low-NOX duct burners, oxidation catalysts, and selective catalytic reduction systems to minimize emissions of regulated pollutants.
  • The estimated emissions of regulated pollutants, including VOC, H2SO4, PM, PM10, PM2.5, NOX, and CO, will be below the NSR major modification thresholds, except for lead and SO2.
  • LG&E is requesting a synthetic emissions limit of less than 40 tpy for VOC and 7 tpy for H2SO4 to avoid PSD and NA-NSR permitting requirements.
  • The planned project will bring a major new capital investment to the Mill Creek Generating Station and help ensure it remains a critical asset for the company to meet energy needs for several decades.
  • The significant decreases in NOX emissions at the Mill Creek Station will contribute to reductions in regional ozone concentrations.
  • LG&E is requesting to obtain the construction permit authorizing the project by October 31, 2026.
  • Documentation of emissions increases and actual emission reductions will be performed as part of this permit action.

Statistics:

  • The proposed Unit 6 will be a 680 MW natural gas-fired combined cycle electric generating unit.
  • The unit will utilize dry-low-NOX combustors, low-NOX duct burners, oxidation catalysts, and selective catalytic reduction systems.
  • The estimated emissions of regulated pollutants during the contemporaneous period will be below the NSR major modification thresholds, except for lead and SO2 (2500 tpy).
  • The new electric generating unit will minimize greenhouse gas emissions by extracting the maximum amount of usable energy from the fuel gas.
  • The planned project will bring a major new capital investment to the Mill Creek Generating Station.

Sources:

  • Louisville Gas & Electric Company - Synthetic Minor Air Permit Application for NGCC Unit 6 (2025)
  • Kentucky Public Service Commission - Brandan Burfict Sr. Manager, Environmental Generation & Gas Operations (2025)