Florida Power & Light on Feb. 4 won an approval from the Florida Department of Environmental Protection of a final air construction permit authorizing the installation of the General Electric 7FA.04 and 7FA.05 components to improve the performance of Unit 2 (Units 2A through 2F) at its Fort Myers Plant.
“The applicant proposes to upgrade the six combustion turbines (Units 2A through 2F),” said the final approval. “The changes will increase the efficiency of each CT by installing new hot gas path components, combustion liners, flow sleeves, compressor air foils and new control software characteristic of the more recent GE Models 7FA.04 and 7FA.05 CT to increase firing temperature and air flow.”
The Fort Myers Plant is comprised of a 1,500-MW six-on-two combined cycle unit (Unit 2); two large simple cycle combustion turbine-electric generators (CTGs); 12 small peaking CTGs and ancillary equipment.
The project for the partial 7FA.04 Unit 2 upgrade project was already approved by the department through a permit issued on March 13, 2014. FPL will now add a partial 7FA.05 upgrade to the project. The key improvement is a compressor enhancement package. The air foil-based compressor continuously pressurizes air that flows parallel to the axis of rotation. The rotating airfoils (rotor blades) and stationary airfoils (stators) will be replaced with more modern 3-dimensional air foils with super finished coatings (such as graphite). The compressor will be converted from an 18 stage compressor to a more efficient 14 stage compressor.
The new compressor components will have improved damage tolerance and reduced blade and contact edge stresses, the DEP noted. “Ultimately the additional electric power generated as a result of the two projects is limited by the electric generator ratings. However at high ambient temperatures, the improvements restore or increase power production at a given temperature. The result is an increase in summer capability at a minimum.”
Department looked at overall gas-fired emissions from FPL
Notable is that in one permitting document, the DEP touched on how the gas-fired generation of Florida Power & Light will grow in coming years in Florida. “Emissions are projected by FPL to decrease in the future despite execution of a project that constitutes an increase in capability (within the ratings of the generators). To test this conclusion, the Department conducted additional technical analysis and examined recent company information submitted to the Florida PSC.
“FPL’s recent (2012-2013) and projected (2014-2020) natural gas usage for generation at its combined cycle (CC) units is presented in Table 3. The source of the information is the FPL 10-year Site Plan submitted to the Florida PSC in April 2014. The Fort Myers (FM) Unit 2 values are from the application.
“According to the information in the table, gas use at combined cycle units in 2020 will be roughly 10% greater than gas use in 2012. However, generation from gas will be 17% greater than in 2012. The key reason is the progressive modernization of the FPL fleet with more efficient combined cycle plants. Examples include the recent modernizations of the Cape Canaveral and Riviera Plants with highly efficient H-Class CTGs and modern STGs. The two projects (each greater than 1,200 MW of summer capability) were placed in service in 2013 and 2014. There is also an ongoing modernization project at the Port Everglades that will be placed in service in 2016.
“The efficient G-Class West County Combined Cycle Units 1, 2 and 3 (each > 1,200 MW of summer capability) were placed in service in 2010-2012. This project was completed after the Fort Myers Unit 2 historical maximum two year baseline heat input, generation and emissions were achieved (2009-2010).
“If the newer installations at Cape Canaveral, Riviera, West County and Port Everglades (totaling 7,200 MW) are dispatched at an 80% capacity factor, they would produce approximately 50,000 GWh. This is a very significant part of the actual or planned generation listed in Table 5. These six highly efficient combined cycle units will be preferentially dispatched compared with Fort Myers Unit 2 even if the Unit 2 CTGs are upgraded to near-7FA.05 CTGs. Additionally the newer installations have more efficient STGs than the vintage 1960s STGs at Fort Myers that were repowered with the 7FA.03 CTGs a dozen years ago.
“The foregoing analysis was conducted without consideration of other possible FPL combined cycle projects considered in the 10-year Site Plan that would also tend to be preferentially dispatched compared with Fort Myers Unit 2.
“The upgrade project will increase instant power from the Fort Myers CTGs and will also result in less fuel use per unit of electric energy produced. Because annual dispatch of Unit 2 in terms of fuel use and generation will be reduced due to the newer units located elsewhere in the FPL system, it is logical to conclude that annual emissions will also be lower in the future compared with the past.”