WESSEX Water plc, the British unit of YTL Power International Bhd, has started testing a Volkswagen Beetle car that is being powered by gas from human waste.
It is the first such test being done in the UK.
"Waste flushed down toilets of just 70 homes in Bristol is enough to power the Bio-Bug for a year, based on an annual mileage of 10,000 miles," the British firm said in a statement posted on its website.
GENeco, a Wessex Water-owned company, imported specialist equipment to treat gas generated at Bristol sewage treatment works in Avonmouth to power the VW Beetle in a way that does not affect its performance.
GENeco general manager Mohammed Saddiq said that methane from sewage sludge can be used as an alternative energy source, and is an innovative way of powering company vehicles.
"We decided to power a vehicle on the gas, offering a sustainable alternative to using fossil fuels. If you were to drive the car, you wouldn't know it was powered by biogas as it performs just like any conventional car. It is probably the most sustainable car around," he said.
To use biogas without affecting vehicle performance, the gas needs to be treated under a process called biogas upgrading. Carbon dioxide will be separated from the biogas using special equipment.
If all the biogas produced at Avonmouth were converted to run cars, it would prevent the emission of around 19,000 tonnes of carbon dioxide.
Mohammed said that while waste flushed down the toilets in homes in the city provides power for the Bio-Bug, it will not be long before further energy can also be produced from food waste recycled at its sewage works.
"It will mean that both human waste and food waste will be put to good use in a sustainable way that diverts waste from going to landfills,"
YTL bought Wessex in 2002 for US$1.7 billion (RM5.35 billion) from Azurix Europe Ltd, a unit of bankrupt energy trader Enron Corp.