Fossil fuels to renewable fuels
Published: Sunday, January 13, 2008 at 6:01 a.m.
Last Modified: Sunday, January 13, 2008 at 12:00 a.m.
Relying on wood and waste for Gainesville's power is full of promise and pitfalls.
GRU's latest power plant options
- The following companies have proposed building biomass power plants for Gainesville Regional Utilities. The proposals include variations on one of three technologies: conventional steam technology; a gasification process that converts solid fuel into steam or a gas; and plasma arc technology that zap solid fuel into a gas. The plant would likely be located near the existing Deerhaven power plant north of Gainesville.
GRU ranked the proposals based on factors such as economics, environmental impact, risk and reliability. The following is a lists the projects based on those rankings, with the highest-rated project listed first.
- * Sterling Planet: 30-megawatt conventional steam plant fueled by wood. Georgia-based company certifies business in making reductions in greenhouse-gas emissions.
- * Covanta Energy: 50-megawatt conventional steam plant fueled by wood, municipal solid waste and tires. New Jersey-based company owns six wood-burning power plants in California and four municipal waste-to-energy plants in Florida.
- * Nacogdoches Power: 100-megawatt conventional steam plant using wood, construction waste and tires. Massachusetts-based company building similar plant in Texas.
- * Taylor Biomass Energy: 35-megawatt gasification plant fueled by wood and municipal waste. New York-based company was tree service business that became recycler of construction and demolition debris.
- ** Envortus: 17.6-megawatt gasification plant fueled by wood and construction waste. Texas-based company formed in 2006 by former CEO of wind turbine manufacturer.
- * NRG Energy: 108-megawatt plasma arc plant fueled by wood and municipal solid waste. New Jersey-based company converting Massachusetts power plant to plasma technology using coal and biomass as fuel.
- * Timberland Harvesters: 32.4-megawatt conventional steam plant fueled by wood. Alabama-based company would supply fuel from its own timberlands.
- * Railex Merchant Energy: 80-megawatt combustion plant fueled by wood. New York-based company would use rails to move supplies to reduce greenhouse gas emissions.&
* Green Power Systems: 35-megawatt plasma arc plant fueled by wood and municipal solid waste. Jacksonville-based company constructing nearly identical plant for Tallahassee utility.
Gainesville Regional Utilities is considering nine proposals from companies competing to build a biomass power plant. Most of the companies are proposing to own the plants, selling energy to GRU under long-term agreements.
The approach ensures the utility isn't stuck with the bill if a plant doesn't work out, said Ed Regan, GRU's chief strategic planner. But it also means companies seeking a profit could charge more for energy than the utility would if it owned the plant.
"Most of the proposals provide a great deal of financial protection for our customers," Regan said. "On the other hand, you pay for that."
GRU ranked the proposals based on factors such as economics, environmental impact, risk and reliability. The Gainesville City Commission is expected to use the rankings to make a short list of proposals on Jan. 28 and make a final choice in April.
The proposed plants are different in size and technology. But they are similar in that they would all be fueled by wood left over from logging and urban tree trimmings.
Most would include garbage or construction waste.
Proponents say the approach would move power generation away from fossil fuels and reduce the need for landfill space. But some environmental advocates question whether burning waste could cause the release of toxic emissions and relying on wood could damage forests.
"The pressure on the Southern forest is going to be tremendous," said John Dickinson, executive director of the Forest Management Trust, a nonprofit sustainable forestry group in Gainesville.
Dickinson supports requiring timber suppliers to be certified in practices that prevent the conversion of older-growth forests to pine plantations. The Southeast has lost more than 95 percent of its longleaf ecosystems, which have been replaced by straight rows of pines that foster a less diverse mix of plants and animals.
The plants would use branches and other parts of the tree left behind in the logging process. Dickinson said removing branches that fertilize soil could cause the depletion of nutrients, encouraging the use of artificial fertilizers.
Gainesville city commissioners last year closed years of contentious debate on a coal-fired power plant by deciding that any new plant would be fueled by wood and possibly waste. Environmental advocates objected to coal because of its contribution to global warming and other environmental harm.
Wood is cleaner than coal but still leads to some of the same emissions, said Eric Waschman, director of the Florida Institute for Sustainable Energy at the University of Florida.
"The emissions from wood are significantly less than coal - but they're not zero," he said.
Waschman said exclusively using wood means avoiding the emission of potentially harmful metals such as arsenic and mercury. But adding garbage and construction waste to the mix could lead to the release of arsenic and other contaminants.
He supports the use of gasification technology, which converts solid fuel into a gas used to produce power. Such a process is efficient, he said, while allowing for the greater capture of pollutants and possibly carbon dioxide that contributes to global warming.
The power plant proposals include variations on three technologies: conventional steam technology, gasification and plasma arc technology. Regan said the first technology is fairly common, the second is less widespread and the third is cutting edge.
Plasma arcs have been used for years to zap waste into a gas and more recently have been considered in public power production. Last year, Jacksonville-based Green Power Systems agreed to build a plasma-arc plant providing power to the city of Tallahassee.
Green Power is one of three proposing to build such a plant for GRU. The technology is starting to be used in biomass power plants because the cost of fossil fuels and landfill space is rising, said Dick Basford, vice president of the company.
"Ten years ago, it wouldn't have worked," he said. "It wouldn't have been economically viable."
But the technology has been plagued with problems and could lead to the emission of harmful dioxins if waste is burned, said Bradley Angel of the San Francisco-based environmental group Greenaction.
Angel's group opposes the use of garbage in power plants, calling such facilities "incinerators in disguise." He supports funding the development of solar power and other renewable energy, saying burning garbage discourages recycling and offers some of the same downsides as coal.
"Pick your poison - do you want to be poisoned by coal ... or do you want to to be poisoned by garbage?" he asked.
New Jersey-based Covanta Energy is one of the companies proposing to use waste to produce power. Covanta owns six wood-burning power plants in California and four waste-to-energy plants in Florida.
The company has incentives to encourage recycling, said Joseph Treshler, vice president for business development in Florida for Covanta. Removing metals from waste makes the plant more efficient and removing plastics puts less stress on pollution controls, he said.
He said those controls make emissions from a waste-to-energy plant similar to a natural gas plant, which burns cleaner than coal.
"They are not emitters of the major-category pollutants by any means," he said.
Three of the plants would exclusively use wood from timberlands and urban trees as a fuel. The proposals come as both the Tallahassee utility and Progress Energy move forward with similar plants in northwest Florida.
Dickinson said the confluence of the plants makes ensuring sustainable forestry practices even more important. But he said timber companies will make a small part of their profit on selling wood debris to utilities, making it difficult to convince them of the need for sustainable forestry.
"There's less incentive for a producer to become certified just to show to GRU they're doing it right," he said.
Nathan Crabbe can be reached at 352-338-3176 or crabben@gville sun.com.
Reader comments posted to this article may be published in our print edition. All rights reserved. This copyrighted material may not be re-published without permission. Links are encouraged.
Comments are currently unavailable on this article