Duke Energy Florida nears permit for new turbines at Suwannee plant

The Florida Department of Environmental Protection is out for comment on a draft approval of an air permit allowing Duke Energy Florida to shut a boiler and replace it with two gas-fired turbines at the Suwannee River power plant.

In May 2014, Duke Energy Florida submitted an application for an air construction permit subject to the preconstruction review requirements or the Prevention of Significant Deterioration (PSD) of Air Quality. The draft approval for the permit was put out for notice on Feb. 26. The plant is located within the city of Live Oak in Suwannee County, Florida.  

The purpose of the project is to construct two nominal 178-MW primarily natural gas-fueled General Electric (GE) 7FA.03 model simple cycle combustion turbines (CT) and ancillary equipment. Ultra-low sulfur distillate (ULSD) fuel oil will be used as a limited backup fuel in the CTs. The ancillary equipment will include: two new natural gas‐fired fuel gas heaters, a new emergency diesel fire pump, a new 2.5 million gallon double‐wall fuel oil storage tank, as well as four new circuit breakers and miscellaneous natural gas piping components.

The existing facility is a nominal 345-MW plant comprised of three fossil fuel-fired steam generators (Boiler Nos. 1, 2, and 3) and three combustion turbine peaking units (CTP Unit Nos. 1, 2, and 3). Boiler Nos. 1, 2, and 3 began operation in 1953, 1954, and 1956 respectively, while CTP Units Nos. 1, 2 and 3 began operation in 1980. The current CTP units generate 189 MW with the boilers contributing 156 MW.

The fuel for the two new CTs will be natural gas (2 grains sulfur/100 scf ‐ primary fuel) and ULSD fuel oil (0.0015% sulfur ‐ limited backup fuel). Natural gas will be delivered to the site by the existing pipeline; however, new piping components will be installed to deliver the fuel to the specific area where the new CTs will be located. ULSD fuel oil delivery will be by truck.

Once commercial operation of the CT peaking units commences, the existing Boiler No. 3 has to be permanently shut down. During the initial startup and shakedown of the CTs, Boiler No. 3 may continue to operate. The new CT peaking units are expected to have an in-service date during February 2016, the department noted.

This project is part of a broader makeover of the utility’s generation fleet

Duke Energy Florida, for clean-air purposes, plans to retire its coal-fired Crystal River Units 1 and 2 in 2018, and also plans to retire due to factors like age some gas- and oil-fired peaking capacity over the next couple of years. This Duke Energy (NYSE: DUK) subsidiary applied Jan. 30 at the Florida Public Service Commission for a ruling that either a possible buy of Calpine‘s (NYSE: CPN) Osprey gas-fired plant, or new simple-cycle gas capacity built at its Suwannee power plant site, is a best way to meet capacity needs out to 2018.

Supplying supporting testimony, with an overview of Duke Energy Florida’s resource needs, was Benjamin M. H. Borsch, employed by Duke Energy as the Director, IRP & Analytics-Florida.

Borsch noted that in February 2013, the company decided to retire its Crystal River Unit 3 nuclear plant (CR3). The company also decided to retire its CR 1 and CR2 coal units earlier than originally planned. These retirements account for over 1,500 MW of summer generation capacity on DEF’s system. The company had planned to retire  CR 1 and CR2 in 2020. But as a result of new EPA regulations, mainly the Mercury and Air Toxics Standards (MATS), the company faced the retirement of CR1 and CR2 as soon as 2015. However, the company now plans to retire CR1 and CR2 in 2018.

These and other retirement decisions and the company’s response to them, coupled with the company’s load growth, create a near-term need for generation, commencing in 2016.

The company also projected the retirement of some of the oldest combustion turbines in its fleet in 2014 and 2016. These combustion turbines were installed in the late 1960s and early 1970s at Avon Park, Turner and Rio Pinar. They collectively provide 133 MW of summer generation capacity to DEF’s system. They are smaller, less efficient combustion turbines and they are increasingly more costly to operate and maintain. The company will retire all of these combustion turbine units by 2016.

The company also plans to retire its three 1950s vintage oil- and gas-fired steam generation units at its Suwannee River site by 2016. These are small units, collectively providing 128 MW of summer capacity to DEF’s system. These units were slated for retirement in 2018 as they approach the end of their life cycle. DEF will retire these units in 2016 to reduce the cost of the transmission upgrades needed for installation of the proposed peakers at this site, which are the preferred alternative to the Osprey power plant buy from Calpine. 

Due largely to the short life extensions for CR1 and CR2, Duke Energy Florida no longer needs up to 1,150 MW of generation capacity commencing in 2016, as it had been projecting a couple of years ago. The company’s need now is approximately 280 MW of summer generation capacity commencing in 2016 that increases to 470 MW in the summer of 2017.

Borsch said the most cost-effective resource plan to meet the company’s summer generation capacity needs commencing in 2016 includes the construction of a new 320-MW simple cycle combustion turbine plant consisting of two F class combustion turbines at the Suwannee River site. This is called the Suwannee Simple Cycle Project. This plan also includes the installation of a 220-MW chillers power uprate project for the company’s existing natural gas-fired, combined cycle power blocks at its Hines Energy Complex (HEC). This is called the Hines Chillers Power Uprate Project.

About Barry Cassell 20414 Articles
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 24 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.