Georgia Power to convert coal plant to wood biomass

By Ryan C. Christiansen
Web exclusive posted August 28, 2008 at 2:16 p.m. CST

Georgia Power, a unit of Southern Co. with headquarters in Atlanta, Ga., has asked the Georgia Public Service Commission for approval to convert its 155 megawatt coal-fired unit at its Mitchell Generating Plant near Albany, Ga., to use wood, instead. The converted unit would produce 96 megawatts of electricity.

According to Lynn Wallace, a company spokeswoman for Georgia Power, the nameplate capacity for the converted wood biomass-powered unit would be 59 megawatts lower due to the different physical characteristics of wood in comparison to coal. Wood contains more moisture and produces only 4,000 British thermal units (Btu) to 5,000 Btu per pound compared to coal at 12,000 Btu per pound, she said.

As a wood biomass-powered unit, the facility would actually produce more electricity than it does as a coal-fired unit, Wallace said. The unit currently operates at low capacity and is not considered one of the company's base-load power units; however, the biomass-powered unit would operate continuously and be part of the company's base load.

Surplus wood fuel for Plant Mitchell would come from suppliers operating within an approximately 100-mile radius of the plant. Wallace said the wood primarily would be waste wood, such as tree limbs, tree tops, needles, and leaves, which is normally left behind by timber harvesting companies. "We wouldn't be competing with their wood supply," she said.

Wallace said consumers are asking to have more energy produced from feedstocks and from processes that produce lower emissions. She said the wood biomass-powered unit will produce less sulfur dioxide and nitrogen oxide emissions and will engender a net reduction in carbon emissions. Wood biomass is also less expensive than coal, Wallace added. The new feedstock requirement for the unit is expected to create between 50 and 75 new jobs related to waste wood recovery. She said waste wood that is left on the forest floor also emits methane gas and can easily fuel forest fires if it's not cleared away.

If approved, the plant would be one of the largest wood biomass plants in the United States, according to the company. The Georgia PSC is expected to rule on the proposal to convert Plant Mitchell to biomass by spring 2009. Retrofit construction would begin by spring 2011 and the biomass plant would likely begin operations in June 2012.

Power generation from wood biomass is nothing new for Georgia Power. The company recently signed a 15-year deal with Greenway Renewable Power LLC, an affiliate of Rollcast Energy Inc., which develops, owns and operates renewable power plants that generate electricity from wood waste. The contracted power supply will come from a biomass-fueled facility which will be located near Franklin, Ga., in the west-central part of the state. The Greenway facility will process timber-harvesting residuals, noncommercial tree species, tree thinnings, lumber scraps and wood waste reclaimed from landfills. Under the contract, Georgia Power will purchase 100 percent of the plant's 50-megawatt capacity. The plant is expected to be operational in 2010.

Georgia Power serves 2.3 million customers in all but four of Georgia's 159 counties.