Sewage-powered buses for Norway’s capital

Buses in Oslo, Norway, are to be powered using biomethane from human sewage.

Starting this year, 200 public buses in Norway’s capital will be fueled using biomethane, cutting back carbon emissions and saving the city council money on fuel costs.

Biomethane gas is a by-product of treated sewage.

Previously, the gas was flared off at sewage plants, releasing 17,000 tonnes of CO2 per year.

Now the gas will be used in slightly modified bus engines. Costing just €0.27 per litre to produce, it is 60% cheaper than diesel.

Net emissions from biomethane are zero, although electricity is used at the sewage treatment plant to convert the gas into bus fuel.

Taking the electricity into account, annual carbon emissions per bus are 18 tonnes; this is 44 tonnes less than diesel buses.

Talking to The Guardian, Ole Jakob Johanse, project leader for the new buses, said: “Oslo aims to be one of the most environmentally sustainable capitals of the world.

“Using biomethane makes sense. Not only would the biomethane otherwise be wasted, but the reduction in emissions per bus will go a long way to achieving our carbon-neutral target.”

Transport contributes 50% of Oslo’s CO2 output.

With Norway aiming to be carbon neutral by 2050 more initatives like this one are likely to follow.