Here’s an interesting pop quiz for the next dinner party you host – what do 80 municipal buses in the Norwegian capital of Oslo use as their source of power?
The answer: human waste.
In an effort to cut carbon dioxide (CO2) emissions and become carbon neutral by 2050, Norway will task two sewage treatment plants to collect methane, a by-product in the microbial process that breaks down sewage, and pump it into city buses. Sound delightful? Well, as much as it might make your dinner guests cringe there is substantial environmental benefits.
According to Ole Jakob Johansen, speaking to the Guardian, using biomethane is a sensible option because otherwise it would be wasted and the fuel actually improves air quality. Collecting methane from the state’s 1.7million cows would, apparently, produce eight billion cubic feet of methane a year – the equivalent of 150million gallons of gasoline.
Of course the process is not quite ‘poo to pump’. Instead, biomethane is produced as part of a four-phase process known as anaerobic digestion with micro-organisms breaking down everything whether it is human waste, leftovers from the slaughterhouse floor or even lawn clippings.
Previously much of the methane simply made its way into the atmosphere – releasing around 17,000 tons of CO2. However, now much of this wasted gas will be captured and used to power buses.
Effectively, this creates a ‘net zero’ situation because the carbon originally came from the atmosphere. Even when the electricity that is used to create the gas is factored into the equation, around 44 tons of CO2 per bus are expected to be saved every year.
