DeSoto County Generating Co. LLC, the owner and operator of the DeSoto Facility, a 310-MW (summer net) simple-cycle combustion turbine plant has raised issues with the Florida Public Service Commission about Tampa Electric’s plan to uprate the natural gas-fired units at its Polk power plant.
Tampa, a unit of TECO Energy (NYSE: TE), applied Sept. 12 at the commission for approval of the uprate project, which involves turning the simple cycle combustion turbines at Polk into combined-cycle facilities.
DeSoto County Generating, in a Nov. 14 motion to intervene in the case, noted that its DeSoto Facility is located in Arcadia, Fla., and is interconnected to Florida Power & Light‘s transmission system and to the Florida Gas Transmission natural gas pipeline. The facility consists of two GE 7241FA combustion turbine (CT) units with a combined summer net generating capacity of 310 MW when firing natural gas (they can also fire No. 2 fuel oil). The facility achieved commercial operation in June 2002 and has operated reliably since that time, supplying wholesale power to a number of Florida utilities, the company noted.
DeSoto said that it participated in a Tampa Electric request for proposals (RFP) for capacity prior to the utility’s announcement of the uprate plan. DeSoto submitted its proposal on May 22 and was notified by Tampa Electric that it had been selected to a “short list” of bidders on June 22. DeSoto said it submitted its best and final offer on July 13, but was notified that it was not selected as the preferred power supply option on July 27.
According to data presented in Tampa Electric’s Polk uprate application, the estimated cost of converting the existing CTs at Polk is approximately $610m (or about $1,325/kWH of incremental capacity), not including AFUDC, DeSoto noted. “It is unclear how the cost of the existing CTs, the last of which began commercial operation in 2007, is accounted for,” it added. “Further, according to data provided in Tampa Electric’s 2012 Ten Year Site Plan (TYSP), Tampa Electric would need to add a new CT in 2019 following the Polk Conversion Project, at a cost of approximately $878 per kW of capacity, presumably to replace a portion of the CT capacity lost with the Polk Project Conversion. It is unclear whether this figure includes any costs for transmission upgrades that might be necessary to integrate the planned 2019 CT.”
DeSoto said it offered to sell its power plant to Tampa
DeSoto said that its best and final offer to Tampa Electric provided the utility with the opportunity to purchase the DeSoto Facility, with its 310 MW of capacity, at a cost that is a redacted percentage less than the estimated total capital cost of capacity for the Polk conversion and a redacted percentage less than the cost of Tampa Electric’s planned 2019 CT unit. “Although DeSoto indicated a willingness to negotiate the terms and conditions of the offer, Tampa Electric did not engage in negotiations or discussions with DeSoto,” the company added.
“[B]y purchasing the DeSoto Generating Facility, Tampa Electric would get twice the capacity of its planned 2019 CT unit, at a lower total cost than for the planned 2019 CT unit, which has approximately half the capacity of the DeSoto Facility,” DeSoto wrote. “Adding the DeSoto Generating Facility to Tampa Electric’s generating fleet in the 2013-2016 timeframe, as offered by DeSoto, would provide cost-effective CT capacity to Tampa Electric while preserving additional flexibility for Tampa Electric to add the Polk Conversion Project at such future time as would best and most cost-effectively meet the needs of Tampa Electric’s customers. Accordingly, DeSoto believes that Tampa Electric and its customers will likely be better served by Tampa Electric purchasing the DeSoto Generating Facility and deferring construction of the Polk Conversion Project to a future date.”
Tampa Electric filed a Nov. 16 motion with the commission that didn’t address the issues raised by DeSoto, but does address the technical aspects of how it raised them. “If allowed to intervene, DeSoto takes this case as it finds it and should adhere to the issues as stated in the Order Establishing Procedure, which Staff and Tampa Electric adhered to in preparing their Prehearing Statements,” Tampa wrote.
Unit 1 at Polk, a coal and petroleum coke gasification facility, is not involved in the uprate project. The site currently consists of Unit 1, a 220-MW IGCC, and four combustion turbines (CTs) totaling a net 604 MW in the summer. The Polk 2-5 revamp project is expected to generate a net 1,195 MW in winter and 1,063 MW in the summer. Tampa first announced this project on Aug. 22.
“Polk 2-5 will result from the conversion of Tampa Electric’s four existing CT generating units, Polk 2 through 5, at Polk Power Station into a modern NGCC generating facility, thereby making efficient and economic use of what is otherwise waste heat exhausted from the existing CTs,” Tampa said in the application.
The energy from this waste heat would be captured in four new heat recovery steam generators (HRSGs). The steam created in the HRSGs would be directed to a single steam turbine generator. With additional supplemental firing of the HRSGs the single steam turbine will generate 459 MW of summer capacity and 463 MW of winter capacity.
This generation will allow Tampa Electric to meet a projected need for additional generating resources that begins in 2017 and increases each year thereafter.