It is available for free in huge quantities, is not owned by Saudi Arabia and it contributes minimally towards climate change. The latest green fuel might seem like the dream answer to climate crisis, but until recently raw sewage has been seen as a waste disposal problem rather than a power source. Now Norway’s capital city is proving that its citizens can contribute to the city’s green credentials without even realising it...
Biomethane is a by-product of treated sewage. Microbes break down the raw material and release the gas, which can then be used in slightly modified engines. Previously at one of the sewage plants in the city half of the gas was flared off, emitting 17,00 tonnes of CO2. From September 2009, this gas will be trapped and converted into biomethane to run 200 of the city’s public buses.
Project leader, Ole Jakob Johansen said: “The city of Oslo has great visions for Oslo as a green capital. 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. What’s more, aside from the intial set-up costs, we expect to see an average saving of €0.40 per litre of fuel (based on an average diesel price of €0.67 per litre compared with biomethane at €0.27 per litre)”.
http://ecoworldly.com/2009/01/29/human-sewage-to-power-buses-in-norway/