Tampa Electric Will Convert Big Bend Coal Plant to Natural Gas

An executive with the parent company of Tampa Electric said the utility plans to seek regulatory approval to convert its Big Bend Power Station in Florida, the oldest and last major coal-fired facility in its fleet, to natural gas.

Rob Bennett, speaking at a breakfast gathering in Tampa on January 12, said an engineering analysis of the switch has been underway for a few years. “It’s a big decision,” said Bennett, who was named CEO of newly formed Emera Technologies last month after overseeing Emera Inc.’s integration with TECO Energy, which Emera Inc. acquired in July 2016. TECO has operated Tampa Electric for many years. “It has to work. It has to make sense for 35 or 40 years,” Bennett said of the plan.

Big Bend has four coal-fired units, the first of which came online in 1970; Unit 4 began operation in 1985. The 1,730-MW plant in Apollo Beach, south of Tampa across Tampa Bay, has a troubled history; most recently, five workers at the plant, including a senior plant manager and four contract workers, were killed in an accident June 29, 2017, which occurred as the workers were trying to clean hardened slag, a by-product of burning coal, from the bottom of a tank where slag cools. The generator’s boiler was still operating when a blockage in the drain area burst, sending thousands of gallons of the intensely hot slag onto the workers. A sixth worker survived but had serious injuries.

After the accident, a report in the Tampa Bay Times newspaper said a similar accident had occurred at another Tampa Electric plant in 1997, and that the utility had moved to ban the cleaning practice, only to continue to allow it.

Tampa Electric in December 2017 was fined $126,749 by the federal Occupational Safety and Health Administration (OSHA), which cited the utility for a “willful” violation, a designation in which OSHA says a company has intentionally disregarded OSHA rules or acted with indifference toward employee safety. OSHA also issued more than $34,000 in additional fines in connection with the incident.

The plant also was cited by the Environmental Protection Agency (EPA) in November 1999, when the EPA said Big Bend and a sister plant, the Gannon Station near Tampa, violated the Clean Air Act. Tampa Electric paid a $3.5 million civil penalty, said it would make major capital upgrades to Big Bend, and in December 1999 announced a $1 billion program in conjunction with the Florida Department of Environment Protection—the major feature of which was a plan to convert Gannon from coal to natural gas at a cost of $600 million.

Gannon was renamed as the H.L. Culbreath Bayside Power Station. It first gas-fired unit began commercial service in May 2003; a second gas-fired unit came online in January 2004. Today the plant has a generation capacity of 1,800 MW. A third Tampa Electric plant, the Polk Power Station, in Bradley in Polk County, is an integrated gasification combined-cycle (IGCC) plant using a combination of coal and gas that underwent a major expansion in 2017.

The four coal-fired units at Big Bend, which also is home to a manatee viewing center that is a popular tourist attraction on Florida’s West Coast, are known as “wet-bottom boilers” because they use water to cool the slag that is left after burning coal. The wet-bottom boilers have been phased out in the U.S. over the past several years, and only a few electric utilities still use the technology. The U.S. Energy Information Administration (EIA) says Tampa Electric is the only utility in Florida still using the boiler.

Details of Tampa Electric’s plan for Big Bend include initially converting the older two coal-fired units to combined cycle natural gas generators, in a combined heat and power (CHP) system. The two newer units then would be converted to natural gas over the next decade.

Bennett said the conversion was a business decision, aimed at lowering emissions by moving from coal to natural gas, and was not being done for safety reasons in the wake of the 2017 fatalities.

“The fact is we need the Big Bend power plant, and we need some kind of fossil fuel generation, at least for a period of time until other technologies advance enough so we don’t have to depend on fossil fuels,” he said, adding that switching from coal to natural gas is “the most economic and environmentally responsible thing to do. That’s what makes the most sense to us right now … that, and add more solar.”

Bennett said Tampa Electric plans to spend more than $850 million over the next few years to create at least 10 “very large solar farms” on about 5,000 acres the utility has purchased. He said the project, involving the installation of more than 6 million solar panels, would have a generation capacity of 600 MW, which would be about 7% of the utility’s output.

Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWERmagazine).