Hoping for a Green Renewal, Mich. City Will Turn Sewage to Fuel

Kettering Provost Michael Harris said biogas will cost significantly more to produce per gallon than gasoline, though it is still a viable undertaking for Flint because the city will eliminate the cost of burning sewage sludge, the solid waste left behind after water is extracted.

But Swedish Biogas President Peter Unden believes the Flint plant can produce biogas that is 20 percent less expensive than gasoline. "From our experience, I feel very confident we can produce biogas cheaply," he said. "Otherwise, it is difficult to introduce something new."

Leo Thomason, director of consulting and technical training for the Alternative Fuel Vehicle Institute, said turning the methane that comes from waste into the type of compressed gas needed for vehicles is an expensive process, and until now few companies or governments have considered it cost-effective.

"The question is, can you clean it up and compress it and then compete with gasoline?" he said. "It depends on the price of gasoline. The volume [from a sewage-treatment plant] is so small, it might be economically inefficient to recover it."

The Flint project is modeled on one in the Swedish city of Linkoping, where drivers who use biogas get free parking and do not have to pay tolls. Michigan Gov. Jennifer M. Granholm (D), whose paternal grandfather was Swedish, visited Sweden last fall in search of an alternative fuel technology to invest in. The U.S. ambassador to Sweden, Michael Wood, grew up in Flint and connected the governor with Swedish Biogas.

The company has been producing biogas since the 1950s and using it for vehicles since 1992, according to Unden. He said the Swedes are world leaders in biogas technology, which is more costly up front but ultimately more profitable.

"It depends if you're looking at the waste problem or at using biogas as a renewable resource," Unden said. "The mind-set is very different. We've been looking at it as an alternative fuel for a long time, so we've been able to develop technologies that make it more efficient."

Michigan's Centers of Energy Excellence program was launched by the state this summer to fund and foster alternative energy projects, including a cellulosic ethanol facility in the Upper Peninsula and lithium car battery research and manufacture by an Ann Arbor company.

Sweden's King Carl XVI Gustaf ceremonially broke ground on the biogas plant in Flint on Sept. 26. The project will start small, fueling up to 30 buses and creating about 20 jobs. But city and state officials hope it can be a magnet for more alternative-fuel investment in Flint and a prototype for similar biogas projects around the nation.

Kettering University will convert the bus engines to run on biogas instead of gasoline, a fairly costly process. The engines will be able to burn natural gas or biogas; in Sweden cars with such engines are common on the private market.