Board approves administrative amendment updating Duke Energy emission factors for two gas units; staff says it may slightly raise tonnage fees

Staff member James explained an administrative amendment from Duke Energy that updates emission factors for two units (units 5 and 7) based on testing. He told the board the company tested one unit and used that result as representative; the new test result raised the emission factor used to calculate particulate emissions for those units. "They tested that unit to, create a new emission factor," James said, and staff noted the change will make reported emissions higher under the permit’s accounting method.

James said Duke Energy is currently operating substantially below the permit cap (the company was described as roughly in the upper sixties of tons versus a cap of about 95 tons), leaving headroom even after the emission-factor increase. He said the amendment is administrative and does not fundamentally change the permit conditions, but because tonnage fees are tied to calculated tons of emissions, the facility could see a small increase in tonnage fees once the new factors are applied.

Board members asked whether testing had been done for peaking units as well; staff answered that those units had been tested previously and that the company submitted factors for equipment the agency agreed with. After discussion, a motion to approve the administrative amendment was made, seconded, and approved by voice vote.

The board did not amend fees at the meeting; staff will implement the administrative amendment and monitor any fee changes that follow from updated tonnage calculations.