Duke Energy Florida seeks okay for 1,640-MW power project

This facility is due for phased operation in 2018

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Duke Energy Florida on May 27 formally petitioned the Florida Public Service Commission for approval of its recently-announced Citrus County Combined Cycle Power Plant, to be located at its Crystal River power plant site.

The Citrus County plant will be a modern, natural gas-fired, combined cycle plant with an expected summer rating of 1,640 MW and an expected winter rating of 1,820 MW when completed in December 2018.

The Duke Energy (NYSE:DUK) utility had formally announced plans for the self-build proposal May 13.

“The Citrus County Combined Cycle Power Plant will enable the Company to meet the reliability needs of DEF’s customers, it will provide a superior source of efficient, cost-effective power to DEF’s customers during its life, it will expand the Company’s natural gas fuel supply diversity, and it adds flexibility to the energy production resources on the DEF system,” the utility said. “There simply is no more cost-effective, viable generation resource to meet DEF’s capacity needs beginning in 2018 to provide reliable power to DEF’s customers.”

The Duke utility currently has a total summer net generation capacity resource of 11,275 MW. This generation capacity resource includes utility purchased power (413 MW), non-utility purchased power (1,704 MW), combustion turbine (2,471 MW), fossil steam (3,410 MW), and combined-cycle plants (3,277 MW).

Construction of 820 MW of the 1,640 MW of the Citrus County plant will be complete by May 2018, with the remaining 820 MW complete by December 2018.

The plant will be an advanced class gas turbine, 4x2 combined-cycle configuration, which includes four combustion turbines (CTGs), four heat recovery steam generators (HRSGs), two steam turbines (STGs), and six generator step-up transformers (GSUs). In addition, the plant will have moderate duct firing capability, which means 50 MW to 100 MW of duct-fired output of each 820 MW power block will be available as cost-effective peaking capacity. The plant will also include cooling towers, pumps, tanks, power distribution centers, a water treatment building, and an administration building.

Gas to be supplied early on by Sabal Trail

The natural gas will be supplied by the Sabal Trail Transmission LLC pipeline through a gas lateral to the plant. DEF has contracted with Sabal Trail for 300,000 MMBtu/day of firm gas transportation capacity on the Sabal Trail pipeline to support the plant’s natural gas needs. Sabal Trail is a new greenfield interstate natural gas pipeline project that originates in Alabama, extends through Georgia, and ends in Central Florida.

Other gas pipelines into Florida will be available as additional resources in the event of a supply disruption on the Sabal Trail pipeline. DEF will have additional receipt only interconnects between Sabal Trail and Florida Gas Transmission Co. LLC (FGT).

Locating this power plant adjacent to the Crystal River facility allows the company to use the existing Crystal River power plant intake canal for sea water makeup for the Citrus County plant cooling towers and the existing Crystal River water wells for process makeup water for the plant. The company also will use existing roads into the Crystal River site for access to the Citrus County plant for construction of the plant and operation of the facility.

The cost to build the Citrus County plant is estimated to be $1.35bn (nominal), plus $164m (nominal) for Allowance for Funds Used During Construction (AFUDC), for a total cost of $1.514bn (nominal). This includes: the cost of equipment; the engineering, procurement, and construction (EPC) contract; transmission; licensing; and internal costs such as construction management and start-up costs.

The only transmission work that is necessary for the Citrus County plant is the switchyard and transmission bus line work to actually connect it with the existing DEF transmission facilities that are already connected to DEF’s transmission system. One 820-MW block of the 1,640-MW plant will be connected to the existing 500-kV transmission system located at the Crystal River plant effectively replacing the generation from the retired Crystal River Unit 3 nuclear unit (CR3). The other plant power block will be connected to the Crystal River 230-kV transmission system, effectively replacing the CR Unit 1 (CR1) and CR Unit 2 (CR2) generation when those coal-fired facilities are retired.

This plant will replace coal and other capacity headed for retirement

By the summer of 2018, when 820 MW of the Citrus County plant is projected to first come on-line, the summer peak demand is projected to grow to 9,439 MW and by the next summer, when the Citrus County plant is expected to be fully operational, the summer peak demand will reach 9,813 MW. This is an annual growth in peak summer demand of approximately 1.4%. This peak summer demand growth results in a summer Reserve Margin of 11.7% by 2018 without additional resources to DEF’s system.

Generation facility retirements also contribute to the company’s reliability needs in the summer of 2018. In February 2013, Duke Energy Florida decided to retire its already-idled CR3 nuclear unit, which had provided approximately 790 MW in summer capacity.

The company also plans to retire its oldest coal-fired units, CR1 and CR2, timed to coincide with the addition of the Citrus County plant. CR1 and CR2 are 1960s vintage coal units with a combined summer capacity of about 740 MW. The U.S. Environmental Protection Agency and the Florida Department of Environmental Protection established air emission standards and limits that affect the continued operation of CR1 and CR2 beyond 2018 without substantial investment in new environmental compliance equipment and measures for CR1 and CR2.

In addition, the company plans to retire its oldest peaking units, built in the 1960s and early 1970s, and its three 1950s vintage steam generation plants at its Suwannee power plant site prior to 2018. These retirements account for another 260 MW of summer generation capacity.

Through the company’s integrated resource plan (IRP) process DEF developed the company’s Base Generation Expansion Plan to meet this need. The plan includes the addition of the Suwannee Simple Cycle Project, involving the construction of two new combustion turbine units at the existing Suwannee power plant site in 2016, and the Hines Chillers Power Uprate project at the Hines Energy Complex by 2017. 

Barry Cassell
About the Author

Barry Cassell

Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 26 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.

Barry can be reached at barryc@pennwell.com.

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