The UK’s first bus powered by human waste has taken to the road in Bristol in a move its Avonmouth-based engineers believe could provide a sustainable way of fuelling public transport by cutting emissions in polluted towns and cities.
The 40-seater Bio-Bus runs on gas generated through the treatment of sewage and food waste unfit for human consumption. It produces fewer emissions than traditional diesel engines and the products supplying it power are both renewable and sustainable.
The bus can travel up to 300km on a full tank of gas generated at Bristol sewage treatment works – a plant run by GENeco, a subsidiary of Wessex Water.
This week GENeco became the first company in the UK to start injecting gas generated from food waste and sewage into the national gas grid network and at the same time installed a gas refuelling plant for the bus.
GENeco general manager Mohammed Saddiq said: “Through treating sewage and food that’s unfit for human consumption we’re able to produce enough biomethane to provide a significant supply of gas to the national gas network that’s capable of powering almost 8,500 homes as well as fuelling the Bio-Bus.
“Gas powered vehicles have an important role to play in improving air quality in UK cities, but the Bio-Bus goes further than that and is actually powered by people living in the local area, including quite possibly those on the bus itself.
“Using biomethane in this way not only provides a sustainable fuel, but also reduces our reliance on traditional fossil fuels.”
The Bio-Bus can travel up to 300km on a full tank of gas, which takes the annual waste of around five people to produce.
Using the annual waste generated from one bus load of passengers would provide enough power for it to travel a return journey from Land’s End to John O’Groats.
The first passengers to board the Bio-Bus were visitors to the UK travelling from Bristol Airport to Bath.
Bath Bus Company, part of the RATP Dev UK group, is operating the bus on its rapidly-growing A4 service from Bath to Bristol Airport via South Bristol.
Engineering director Collin Field said: “Up to 10,000 passengers are expected to travel on the A4 service in a month, which is available not only for airport travel, but also local journeys along the route through Saltford, Keynsham, Brislington, Knowle and Hengrove.
“This represents RATP Dev’s involvement in the latest of a number of initiatives to gain experience of alternative fuels, with sister companies also experimenting with different alternatives. The information we gain, will be shared with other group companies across the UK and Europe.
“The timing of this initiative could not be more appropriate as we approach 2015 when Bristol becomes European Green Capital. With so much attention being directed towards improving air quality generally, the public reaction to the appearance of this bus on a service between a World Heritage City and an airport will further focus on the potential for this particular fuel.”
Bristol Airport environmental manager Melanie King added: “Sustainability and surface access are key areas of focus for us and we welcome new technologies which could reduce the environmental impact of getting to and from the airport. With Bristol set to be European Green Capital in 2015, this is one of several exciting initiatives we hope to be involved with over the course of the year.”
Bristol sewage treatment works treats around 75m cubic metres of sewage waste and 35,000 tonnes of food waste, collected from households, supermarkets and food manufacturers, every year.
Through a process known as anaerobic digestion, 17m cubic metres of biomethane is generated a year at the Bristol plant – the equivalent of meeting the power needs of 8,300 homes. A newly built state-of-the-art gas plant injects the gas into the grid.
Anaerobic Digestion & Bioresources Association (ADBA) chief executive Charlotte Morton said: “GENeco’s Bio-Bus is an excellent demonstration of biomethane’s unique benefits; decarbonising areas other renewables can’t reach. A home-generated green gas, biomethane is capable of replacing around 10% of the UK’s domestic gas needs and is currently the only renewable fuel available for HGVs.
“The bus also clearly shows that human poo and our waste food are valuable resources. Food which is unsuitable for human consumption should be separately collected and recycled through anaerobic digestion into green gas and biofertilisers, not wasted in landfill sites or incinerators. The Bio-Bus will also help to demonstrate the true value of separate food waste collections, which are now obligatory in all other regions, to the Government.”
The Bio-Bus has received backing from a number of businesses including its manufacturer Scania as well as companies including Roadgas, CNG Services, Dampney’s Agri Environmental, Trant, Grontmij and AIR Decker.
In 2010 GENeco powered a car on biomethane produced during the sewage treatment process. The Bio-Bug was used in various trials to see how viable it was to power a vehicle on sewage gas.
