Florida Power & Light is pursuing an air permit on a revamped version of a plan to add new gas-fired capacity at its existing Lauderdale Plant in Broward County, Florida.
The utility on April 9 filed at the Florida Department of Environmental Protection an air permit application, written by consultant Golder Associates, for this project.
The plant now includes two banks of 12 simple cycle gas turbines (GTs) (GT1 through GT12 and GT13 through GT24). GT Units 1 through 12 began operation in 1970, and the commercial in-service dates for GT Units 13 through 24 were in 1972. Each bank of GTs has a nominal net capacity of 504 MW. GT Units 1 through 24 are authorized to operate on natural gas and distillate oil.
These existing 24 GTs located in Broward County are first generation GTs that are used to serve peak and emergency demands in a quick-start manner. Each unit consists of two aeroderivative GTs coupled with a single gas flow driven turbine-electric generator. These units have low stack heights and relatively high SO2 emission rates when firing distillate oil and high NOX emissions rates when firing natural gas and oil, as is typical of these older generation units.
The low stack heights in proximity to nearby property boundaries result in decreased dispersion properties and, when combined with the relatively high NOX emission rates, result in elevated concentrations of air pollutants. FPL also has 12 similar GTs at the Port Everglades Plant, which is also located in Broward County.
FPL planned in 2013 to bring five new CTs into service at Lauderdale Plant to replace 34 of the existing GTs at Lauderdale and Port Everglades. It submitted an Air Construction/prevention of Significant Deterioration (PSD) application to the Florida DEP in August 2013. A separate PSD Permit application was submitted to EPA Region 4 for Greenhouse Gases (GHGs) since FDEP did not have authority for PSD review of GHGs at the time. FDEP issued a permit in April 2014 for the project but without authorization for GHGs. The GHG PSD application submitted to EPA was withdrawn since FDEP was seeking approval from EPA for authority for PSD approval for GHGs.
FPL now plans on going forward with the project using specific combustion turbines. In addition, FPL has decided to keep two of the existing GTs at the Lauderdale Plant for black start capability and the generation, and black start diesel generators authorized by FDEP in the 2014 Air Construction/PSD Permit will no longer be part of the project. This April 9 application is a revision to the FDEP Air Construction/PSD Permit to incorporate the latest CT design, change in PSD applicability for SO2 and VOCs, and to seek PSD approval for emissions of GHGs.
Lauderdale project to feature five GE turbines
The revamped project consists of five General Electric 7F.05 combustion turbines (CTs) and supporting equipment. These five CTs will be located at the Lauderdale Plant and will be referred to as the Lauderdale CT Project. The new CTs will be designated Units 6A through 6E. Retiring and dismantlement of the existing GTs will occur after new CTs are operational in order to maintain peak service capability in south Florida. Following commercial operation of the project, there will be no overlap of operation between the existing 22 GTs that will be decommissioned and new CTs after the project is complete.
“There will be significant benefits associated with the Project,” the application said. “The five new CTs will be more energy efficient than the existing 34 GTs and will provide cleaner energy to FPL’s customers. For the same amount of generation, the new CTs will use 30 to 40 percent less fuel and have approximately 90 percent lower NOX emission rates. The maximum total air quality impacts for the Project are predicted to be well below existing levels and in compliance with the new NAAQS for NO2. For pollutants such as NO2, the Project’s total air quality impacts are predicted to be significantly (40 percent or more) lower, than those predicted for the existing GTs.
“Each CT will utilize inlet air cooling consisting of evaporative cooling and wet compression. Evaporative cooling systems achieve adiabatic cooling using water in the form of water evaporated from evaporative cooling media. The evaporating water cools the inlet air stream when the water droplets are converted to water vapor. Inlet air temperature is reduced as heat is transferred at a rate of 1,075 British thermal units per pound (Btu/lb) of evaporated water. The result is a cooler, denser air stream, allowing additional power to be produced. Wet compression introduces water droplets near the compressor inlet resulting in increased power through compressed air cooling and increased mass flow. The CTs will use natural gas and ultra low sulfur distillate (ULSD) oil as fuel. ULSD oil will be used for up to the equivalent of 500 hours per year (hr/yr) per CT at base load conditions. Natural gas will be transported to the facility via an existing pipeline. ULSD oil will be delivered to the facility by truck or pipeline and will be stored in ULSD oil storage tanks.
“The CTs (any of the models under consideration or equivalent) will use low-NOx combustion technology or equivalent when firing natural gas and water injection when firing ULSD oil to minimize formation of NOx. Natural gas and ULSD oil will be used as fuel. While FPL envisions that the new CTs will be operated as peaking and emergency capacity like the existing GTs, FPL is conservatively seeking permitting authority for maximum operation of 3,390 hr/yr (base load equivalent hours) for each CT of which ULSD oil usage is up to 500 hr/yr (base load equivalent hours). This is an accepted operating assumption for permitting simple-cycle CTs in Florida.
“The purpose of the Project is to replace existing 40+ year old GTs with five new CTs going into service by December 31, 2016, continuing to provide emergency and peaking duty service for FPL’s electric system. Emergency and peaking duty service refers to meeting the needs of power generation when there is an electric demand caused by unit outages or system electric disruptions, and/or high electrical demand. As a result, short startup periods are required and simple-cycle CT technologies meet the requirements.”