While it’s been the subject of many crappy puns (this one included) the UK’s first human waste powered bus is no laughing matter. The Bristol Airport to Bath city centre shuttle runs on biomethane gas, produced using anaerobic digestion — a process in which microorganisms break down biodegradable material (in this case, poop) in the absence of oxygen.
The 40-seater bio bus is able to travel 300 kilometres on one tank of fuel, which amounts to about five people’s annual excrement.
The fuel is synthesized by GENeco, a local waste treatment facility. The biomethane gas is essentially odour-free and is used to power nearly 8,500 homes in addition to the bio bus. It’s also an entirely renewable energy source.
Exhaust emissions from diesel engines emit harmful pollutants and soot — which the bio bus will reduce by 97 per cent. It’s not entirely sustainable, as it still releases carbon dioxide, but at a level that is 20 to 30 per cent less than that of a diesel bus.
The road to green energy, it seems, may be a bit browner than previously thought.