This is worth investigating.
Swedish Environmental Protection Agency: Biogas used in buses
|Digesters in Ulsan, South Korea|
As the Swedes learn more and more about making and using biogas, they are taking advantage of their unique knowledge and exporting what they have learned, for a fee, around the world. Scandinavian Biogas worked with the city of Ulsan, South Korea to improve its biogas production and increase its treatment of food waste at a city wastewater treatment plant.
Another new source of power for buses plying urban routes is the fuel cell. Sau Paulo, Brazil, is getting 25 Ballard fuel cell powered buses. There are 21 more going to Europe.
A Ballard fuel cell powered fleet of 20 buses in British Columbia is said to be the largest hydrogen fuel cell-powered bus fleet in operation anywhere since it went into service approximately 2-years ago. It is the first such fleet to hit (and surpass) one million miles (1.6 million kilometers) of revenue service.
The buses went into service in January, 2010 prior to the 2010 Olympic and Paralympic Winter Games.
Read more here: Fuel cell bus fleets.
London experimented with natural gas powered buses but rushed into the purchase of the vehicles and then rushed out of the natural gas experiment just as quickly. They didn't do their homework and it showed. (I know as I covered the story for The London Free Press. Well, I shot the pictures.)