Air Pollution Control Equipment Services, Emissions

Polk Power Station Celebrates 15 Years of Innovation

Issue 11 and Volume 116.

Polk Power Station is a 260-MW IGCC facility that converts coal into syngas, which fuels a conventional combined-cycle power plant. The facility has earned worldwide recognition for the way it produces coal-fired electricity. Photo courtesy of Tampa Electric
Polk Power Station is a 260-MW IGCC facility that converts coal into syngas, which fuels a conventional combined-cycle power plant. The facility has earned worldwide recognition for the way it produces coal-fired electricity. Photo courtesy of Tampa Electric

By Cherie Jacobs, Tampa Electric

From its inception, Tampa Electric’s Polk Power Station was a pioneer.

The Integrated Gasification Combined-Cycle (IGCC) plant came about because of a $120 million award from the U.S. Department of Energy (DOE) for the development of a project using clean-coal technology.

The plant’s location was chosen by a task force of 17 local business folks, environmentalists, academics and others. The task force selected 4,300 acres of former phosphate mining land in rural Polk County, Fla. That collaborative approach carried over in the unique organizational design of the station and its true team-based culture.

On Sept. 30, 1996, Polk Power Station began commercial operation, launching a new chapter in innovation for the investor-owned utility with 677,000 customers in West Central Florida. Since then, the 260-megawatt IGCC facility has earned worldwide acclaim for the clean way it produces coal-fired electricity.

World leader in clean-coal generation

More than 5,000 people have visited Polk Power Station since it began operations in1996 – a testament to its status as one of the world’s best IGCC power plants.

Tampa Electric is just one of six utilities in the world to use IGCC technology for electric generation, where coal is turned into a clean gas, called syngas, which fuels a conventional combined-cycle power plant. The process also separates air into nitrogen and oxygen, using the nitrogen to reduce emissions and the oxygen to produce the syngas fuel. Any additional heat from making the syngas returns to the station to generate more electricity, which makes the system highly efficient.

IGCC has brought Polk Power Station industrywide recognition. Energy Probe, a Toronto-based consumer and environmental public interest group, put Polk ahead of 402 other power stations as the cleanest coal-fired power station in North America in 2005. And while considered one of the cleanest coal-fired stations, Polk has generated more megawatt-hours from coal-derived syngas than any facility in the world.

Polk has helped prove that IGCC is commercial technology, according to John McDaniel, senior engineering fellow at Polk Power Station.”Although IGCC plants are more expensive to build than natural gas-fired combined-cycle plants, IGCC is competitive for baseload generation when the price of natural gas is at a normal premium to that of coal and/or pet coke.

Expansion planned

The Polk Power Station also includes four simple-cycle natural gas-fired combustion turbine units that produce about 680 megawatts total. To accommodate customer growth and to replace purchased-power agreements due to expire, Tampa Electric plans to expand the power station by renovating the four CTs to create a four-on-one combined-cycle unit.

If the project is approved, Tampa Electric will expand the plant by about 460 megawatts, or enough electricity to power more than 100,000 homes. The expansion would convert the four existing simple-cycle natural gas units to a more efficient combined-cycle unit by January 2017.

The project would capture the waste heat of the existing combustion turbines and increase the output of the gas-fired units by 70 percent without the need to purchase additional land. The project also would improve transmission reliability and dramatically reduce emissions of nitrogen oxide and carbon dioxide of the company’s system.

“Expanding the Polk Power Station provides the best value to customers based on cost, reliability and flexibility, as well as environmental performance,” said Gordon Gillette, president of Tampa Electric.”We are committed to meeting our customers’ needs for safe, reliable, and cost-effective electricity.”

Safety-focused innovation

Safety always has been a focus at Polk Power Station.

“Polk has been a trailblazer in safety programs at Tampa Electric, implementing a near-miss reporting system in 2002 and a behavioral observation program in 2004,” said Vonia Walther, the station’s former safety and industrial health coordinator.”Polk has achieved several years in its history with no OSHA-recordable incidents.”

Aside from safety, Polk employees have focused on sustainability as well. In 2009, Tampa Electric signed an agreement with the city of Lakeland to treat and reuse the city’s reclaimed water as a coolant for the station’s generators, beginning in early 2014. Using reclaimed water will benefit the environment because it avoids drawing groundwater from wells at the station. The additional water will be used for current and future operational needs. And it could play an important role in future expansion plans for Polk Power Station.

Tampa Electric also is involved in another project at Polk with the DOE. In 2010, the DOE selected Polk Power Station as host for a project to demonstrate an advanced sulfur-removal system for even lower emissions. The sulfur-removal process, developed by RTI Inc., includes capturing 90 percent of the carbon dioxide from a 20 percent side stream of the syngas process.

These and other projects at the Polk site reflect an investment of more than $1 billion that creates about 1,000 jobs during their engineering, construction and implementation.

“It’s an honor for Polk to participate in projects that could benefit our company, customers and shareholders – as well as the industry as a whole,” said Polk’s Director Karen Sheffield.