Those who don’t think natural gas is a renewable energy resource haven’t paid much attention to biomethane. Biomethane can be collected from sewage sludge, landfills, grass, food waste, and agricultural waste. Biomethane collection has 2 major benefits: (1) greenhouse gases emissions are prevented and (2) relatively clean energy is provided. See this great article in Renewable Energy World.
Kudos to the city of Olso, which plans to fuel buses with biomethane. The Oslo program has generated some clever headlines:
Flush Hour: Oslo to Run Buses on Biomethane
Norway or the Highway: Poo Powers Oslo Buses
The city’s two sewage plants have enough biomethane to provide fuel for the 80 buses, and if the trial is successful Oslo city council plans to convert all 400 of the public buses to run on biogas.
Bud's Offshore Energy (BOE) 