Turning trash into electricity is a better bet for the environment and local government budgets than burying it in landfills, said experts who convened at UNC Charlotte last week.
In the world of waste, they say, landfills are considered the crudest form of disposal. They gobble land, burp up greenhouse gases and waste potential energy sources.
North Carolina relies so much on landfills, burying 84 percent of its trash, that it ranks with Slovakia on an international index of waste-management sophistication, said Columbia University scientist Nickolas Themelis. That doesn’t mean trash-fueled power plants, like the gasification design proposed for Mecklenburg County’s ReVenture Park, are slam dunks. (Gasification heats trash at high temperatures, releasing gases that are used to make electricity.)
It’s tricky business for the projects to make economic sense and to attract investors, said Bill Davis, who founded the Boston waste-to-energy firm Ze-gen. Fuel costs can rise and fall. Pollution controls may eat up much of the electricity the plant generates. And trash has to be carefully processed into a fuel of consistent quality that’s free of hazardous materials.
“This is the source of my skepticism of waste-to-energy,” said John Bonitz of the Knoxville, Tenn.- based Southern Alliance for Clean Energy. “We have a huge challenge to make sure we can make the waste stream clean enough.” Because the United States has been slow to adopt modern gasification technology, much of Ze-gen’s business is outside the country. But the ReVenture concept is “state-of-the-art thinking” in much of the world, Davis said.
The U.S. has 87 waste-to-energy plants, including one in New Hanover County, and many more are in Japan, China and Europe. Critics of ReVenture Park say the county should instead move toward a “zero-waste” policy to minimize the amount of trash it produces. But countries that recycle and compost most of their trash — the Netherlands, Germany and Sweden, among others — also rely heavily on waste-toenergy plants.
“To not do ReVenture is to landfill, that’s the unfortunate truth,” said Helene Hilger, director of UNCC’s Infrastructure, Design, Environment and Sustainability Center, which hosted the two-day conference. Hilger serves on ReVenture’s advisory board. ReVenture Park, its developer Forsite Development, and three other companies with ties to the project were among conference sponsors.
Not like incinerators
Longtime residents might remember Mecklenburg’s failed foray into trash-burning. A $28 million county-owned incinerator ran only six years before being shut down in 1995 because of high costs and lead-contaminated ash. ReVenture developer Tom McKittrick repeatedly distinguishes gasification plants, which produce electricity and heat, from incinerators that simply dispose of garbage.
Both release air emissions, including carbon monoxide, fine particles, acidic gases and smogforming compounds. Modern pollution controls and combustion techniques catch most of those emissions, said N.C. State University solid-waste scientist Morton Barlaz. “In general, this industry is doing way better than the standards” set by government agencies, he said. Backyard trash-burning is now the leading U.S. source of dioxins and furans, cancercausing compounds that have long been linked to municipal trash incinerators.
ReVenture’s pollution-control vendors guarantee emissions will be within safe limits, McKittrick said. Emissions will be continuously monitored, he said, so problems can be quickly detected. But people who live along the Catawba River in northwest Mecklenburg, where the plant would be built, don’t need another pollution source, says resident Tom Davis. His neighbors recall the groundwater contamination at the Paw Creek tank farm and live within view of the Riverbend coal-fired power plant. The ReVenture tract itself is a federal Superfund hazardous-waste cleanup site. “Our main concern is what’s going to come out of that plant,” he said. Despite two years of prototype tests, no gasification plant of the design intended for Mecklenburg County is in commercial operation.
Sierra Club chair Bill Gupton says the technology is unproven and, he told county commissioners last week, “will turn Mecklenburg County into a test lab.” Gupton charges that the ReVenture project hasn’t received the public scrutiny it deserves. County solid-waste director Bruce Gledhill acknowledges that time is shrinking to either strike a deal with ReVenture to take 370,000 tons a year of residential waste or find other options. The county’s contract with a Cabarrus County landfill expires in mid-2012.