The Florida Department of Environmental Protection on Dec. 19 issued a draft approval on an application from Duke Energy Florida for air permit changes that would allow certain existing units at the Suwannee River Power Plant to run harder in place of other units at the plant that might be retired.
Suwannee River consists of three Twin-Pac simple-cycle combustion turbine peaking units and three fossil fuel steam-fired boilers. The peaking units are referred to as units CTP1, CTP2, and CTP3, and each of the peaking units includes two dual-fuel (natural gas and No. 2 fuel oil) aeroderivative combustion turbines coupled to one electric generator. The boilers are referred to as Unit Nos. 1, 2, and 3. This project involves only the three peaking units, not the boilers.
The DEP noted: “The peaking units have been in operation since 1980. Each simple-cycle unit is currently permitted to operate no more than 1,500 hours per year, regardless of fuel, under the units’ original construction permit (Permit No. PSD-FL-014, issued by US EPA in 1979). DEF has requested that the limitation on permitted hours be replaced with a cap on emissions of nitrogen oxides (NOX). DEF also requests that operation on fuel oil be limited to 1,500 hours per year. Emissions while operating on fuel oil would still count toward the NOX cap. DEF expects greater need for generation from these units in the coming years, as other units at the facility are shut down. While DEF may shut down some or all the boilers at Suwannee soon, the shutdown of the boilers is not included in this present project.”
Each peaking unit includes two combustion turbines coupled to an electric generator with a capacity of 63 MW. The peaking units are fueled with natural gas and with No. 2 distillate fuel oil. Each peaking unit is currently permitted to operate no more than 1,500 hours per year, regardless of fuel.
The proposed air permit changes would be the equivalent of nearly doubling the annual permitted usage of each peaking unit. DEF stated that this additional peaker operation will be needed considering the planned shutdown of the three gas-fired boilers at the facility.