'Clean coal' plant may be healthier alternative

Published: Tuesday, January 31, 2006 at 6:01 a.m.
Last Modified: Monday, January 30, 2006 at 11:49 p.m.
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The Polk Power Station in Tampa is one of two integrated gasification combined cycle facilities in the nation. The 250-megawatt IGCC unit combines coal with oxygen to create a clean-burning gas that fuels the combustion turbine to generate electricity. The gasification process is known for its efficiency and environmentally friendly benefits. An IGCC facility is one option GRU is considering for a new power plant.

TRICIA COYNE/Special to The Sun
Two wisps of steam are the only emissions visible when approaching Tampa Electric's Polk Power Station.
The plant converts coal into gas, allowing pollution to be removed before energy is generated. Proponents say the so-called "clean coal" technology is the best way to produce inexpensive electricity while reducing emissions that harm human health.
The Polk plant is just one of two coal gasification plants in the country, but more are being planned due to huge government subsidies and the technology's potential to capture greenhouse gases. A consultant hired to study Gainesville Regional Utilities' power options has included the technology - called integrated gasification combined cycle, or IGCC- among four possibilities for the area.
Commissioners hired the consultant to analyze GRU's plan to build a $450 to $500 million 220-megawatt coal-fired power plant and to look at other options.
While the consultant is still preparing that report, Gainesville Mayor Pegeen Hanrahan has already touted the technology at a recent city council meeting.
"I think our best bet . . . is IGCC and/or a greater use of biomass plus very aggressive conservation," she said.
Critics say "clean coal" is a misnomer, allowing utilities to avoid investing in renewable energy. Dian Deevey, part of an Alachua County citizens' group studying GRU's plans, said measures to improve conservation and energy efficiency could preclude the need for a new plant here in the immediate future.
But if a plant had to be built, Deevey said coal gasification would provide a good alternative to burning coal.
"If we needed a big power plant, that would probably be a much better way to go," she said.
Such sentiments are music to Vernon Shorter's ears. The Tampa-based energy consultant has helped market gasification for more than 20 years, most recently working with Tampa Electric in promoting its Polk plant.
The 260-megawatt plant began commercial operation in 1996, joining a gasification power plant in Indiana as the only two in the country. Shorter said the technology failed to catch on due to cheap natural gas prices, but as those prices have skyrocketed, that trend has come to a screeching halt.
Gasification provides similar environmental benefits as natural gas at a lower cost, he said. The "combined cycle" method also captures steam from the process to generate additional electricity, helping bring down costs.
"It's by far the low-cost electricity on Tampa Electric's grid," Shorter said.
Coal has been turned into a gas for more than a century, having initially been used to light street lamps. Germany used the technology to produce diesel for tanks during World War II due to its lack of oil.
The United States has come to more heavily rely on coal for similar reasons. But burning coal for power is a dirty process, producing mercury and other health hazards as well as greenhouse gases that contribute to global warming.
Coal-burning plants reduce pollutants by scrubbing them from emissions before they leave the smokestack. The advantage of gasification is that pollutants can be removed before power is produced.
"You're cleaning up your mess before it gets to the turbine," Shorter said.
At the Polk plant, some of the removed pollutants are sold to provide additional revenue for the utility. Fly ash is sold as a component for cement, while sulfur chloride is sold as an ingredient in fertilizer.
The process could also allow mercury and carbon dioxide to be removed, although the Polk plant doesn't employ that technology. The U.S. Department of Energy is pursuing a $1 billion test project, called FutureGen, that would construct a gasification plant totally free of those and other emissions.
The department is deciding where to put the project, which is contingent on having a place to store carbon dioxide. Experts say the gas might be injected into old oil wells, but that North Florida's karst geology would make such a process difficult to manage here.
The 2005 energy bill provides as much as $5.4 billion in additional funds that could subsidize another 16 gasification plants. The government has already committed to paying $235 million of the Orlando Utilities Commission's planned $557 million, 285-330 megawatt gasification plant scheduled to be completed in 2010.
Federal funds also provided $120 million of the Polk plant's $500 million cost. Such support is essential to the technology's growth, said Paul Sotkiewicz, director of energy studies for the Public Utilities Research Center at the University of Florida's business college.
"You don't see anybody rushing out with their own money to build IGCC facilities," he said.
The uncertainty involved in developing new technology can scare off utilities, he said. GRU officials have said they view gasification as too risky and costly, but might more seriously consider the possibility if government subsidies were available.
Shorter said building a gasification plant today would likely cost 10 percent more than a coal-burning plant. But gasification is also 10 percent more efficient in producing power, he said, meaning eventual savings for the utility.
As the technology wins more converts, he said building gasification plants will become no different than traditional coal-fired plants.
"You can cookie-cutter these as well as you can cookie-cutter any plant," he said.
Nathan Crabbe can be reached at 352-338-3176 or crabben@gvillesun.com

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