News Making The Switch

Making The Switch

Making The Switch
February 27, 2003 |

Green dust filled the frigid air as Talladega County farmers David and Doug Wilson watched trailer-truck-size machines grind and compress the hay they baled earlier this year into cubes. For the Wilsons, the noisy process is the latest phase of an experiment that began five years ago when they agreed to plow up 270 acres of pastureland and plant switchgrass for the generation of electricity.Bracing themselves from the winter wind, the third-generation farmers said they are hopeful the dense cubes will finally make switchgrass a viable alternative to coal.”My goal is to get this out of the experimental stage to where they are burning it all the time,” said David Wilson. “I would love to have 3,000 acres in biomass production and eliminate having to plant a crop every year.”As optimistic as that sounds, Wilson’s dream may not be altogether unrealistic. Increasing pressure on energy companies to use environmentally friendly, renewable fuels could create a huge market for biomass crops like switchgrass.Currently, biomass accounts for about 3 percent of the total U.S. energy consumption, according to the Energy Information Administration. But Dr. David Bransby of Auburn University said a bill that stalled in Congress last year could have significantly boosted the use of biomass crops by power companies.”A ton of switchgrass delivered to the power plant costs about $50. At that price, it is more than twice as costly as coal, on an energy basis,” Bransby said. “But in the pending energy bill that we had in Washington last year (which failed to pass) there was a provision that would have given energy companies a 1.5 cent per kilowatt hour tax credit for co-firing biomass with coal. What that ultimately meant was a $30-per-ton reduction in the cost of biomass. That would have made it actually less expensive than coal.”Although the tax credit was in both the House and Senate versions of the energy bill, the bill died under the weight of more controversial provisions. Bransby is hopeful, however, that broad-based support for the use of biomass crops could eventually make them a profitable alternative for Southern farmers.Bransby, who has studied switchgrass production for about 15 years, has proven the crop can be grown successfully in Alabama. In fact, it was Bransby’s research that led to the first tests involving the co-firing of switchgrass with coal at Southern Research Institute in Birmingham and at Alabama Power Company’s Plant Gadsden.Initially, researchers tried mixing switchgrass directly with coal, but the lighter grass would not flow properly through the coal-handling equipment. To remedy the problem, the scientists ground the biomass and injected it directly into the boiler using large fans. This proved successful, but it required the construction of a separate handling system.Dr. Doug Boylan, a research engineer with Southern Company, said the cubing process could eliminate this problem.”Cubing makes the grass work more like coal,” Boylan said. “If it works, we can avoid the capital expense associated with building a new system to handle the grass. Right now, most power generated from biomass is more expensive than that generated from fossil fuels. The point of our research is to try to reduce those expenses as much as possible.”In the current test, Boylan and Southern Company Research Specialist Jack Eastis are cubing switchgrass at the Wilsons’ farm as well as coastal bermudagrass at the Sunbelt Ag Expo in Moultrie, Ga. The cubes will be hauled to Georgia Power Company’s Plant Mitchell in Albany, Ga., where tests will be conducted on how well the cubes mix with coal.To make the cubes, round bales of switchgrass are placed in the same type of tub grinder used to grind large tree stumps. The pulverized grass is then mixed with a binder and is pressed into cubes using a machine similar to those used to make alfalfa cubes or to pelletize landfill waste.Eastis said the researchers are testing a variety of binders including hydrated lime and dried molasses. They also are checking the moisture content of each bale to determine which combination makes the best cube.If they are able to make a cube that flows well when mixed with coal, it could pave the way for expanded testing. Boylan said the environmental benefits of biomass are the driving force behind the study by Southern Company, Georgia Power and the Electric Power Research Institute.”Energy produced from biomass is considered to be a renewable option that not only lowers emissions but also does not contribute appreciably to the level of carbon dioxide in the atmosphere,” Boylan said.In previous tests, Eastis said researchers could see the coal load and carbon dioxide levels drop on their monitors when biomass was injected into the boilers. These encouraging results mean the development of biomass as an alternative fuel is likely to continue. That’s good news for farmers like the Wilsons.”If this works, I think it has great potential for farmers,” Doug Wilson said. “With commodity prices being as low as they’ve been, farmers need another option.”The Wilsons currently farm 2,500 acres of row crops plus 400 acres of forage crops–270 of which are in switchgrass. David Wilson said he believes many farmers could convert their operations to biomass production with little or no added investment. “We have a lot of grass already established in this part of Alabama,” he said. “If they can cube and burn any kind of grass–and I don’t see why they can’t–it would give farmers an option of either raising cattle or growing grass. We haven’t had that option until now.”Bransby said that if one steam plant he studied in west Alabama switched to biomass for just 10 percent of its fuel, it would take 63,000 acres of grass. In addition, Bransby is studying the possibility of using grass for the production of ethanol–which could further expand the potential of biomass as an agricultural crop.”Switchgrass is a great option, but if we needed to plant thousands of acres of switchgrass next year, we couldn’t do it. There’s not enough seed,” Bransby said. “The great thing about co-firing is that you can do it with anything. We have greater potential to do something in the near term with grasses we’ve already got growing out there.”

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