'Poo power': ​UK firm turns human waste into clean energy

A UK power company has revolutionized the supply of gas to homes in a method that extracts energy directly from human waste.

Severn Trent Water (SVT) claims to be the first power company in the UK to provide biomethane gas, created by breaking down the ‘sludge’ in Britain’s sewers. The sludge is a combination of human waste compounds and biodegradable matter.

The cocktail of waste is then cleaned and compressed, before tests ensure it performs like regular gas. Human waste can also be broken down into carbon dioxide, which can then be further refined into biomethane.

SVT, Britain’s second largest publicly traded water company, began sending the natural gas to the National Grid last week, marking the first time any kind of eco-friendly gas has been delivered for public use. The biomethane is developed in SVT’s Minworth treatment plant, a facility which cost £8.4 million (US$13.6 million) to build and can develop clean gas for over two million people.

“Local domestic customers will be able to tap into the energy contained within the biogas and biomethane as it’s injected into the grid,” said SVT’s renewable energy development manager Simon Farris.

While Farris admitted to the BBC that the source material was “a little unsavory,” he said the new method could cut SVT’s carbon emissions by 300,000 tons over the next 20 years.

Other energy producers including Wessex Water and Northumbrian Water also have plans to develop a pipe to supply natural gas from sewers.

“Greenhouse-gas emissions reductions could be significant, as the methane normally generated at sewage works is 25 times more harmful to the atmosphere than carbon dioxide,” Dragan Savic, a professor of hydroinformatics, told The Independent.

“By capturing methane and pumping it into the National Grid, water companies could turn from greenhouse-gas emitters into renewable-energy generators,” Savic said.

There are over 9,000 sewage treatment plants in the UK, although none are used to provide energy to the public.

According to data from the Environment Agency, more than four million tons of greenhouse gases are emitted by the water treatment industry alone, including high concentrations of nitrous oxide – a gas claimed to be almost 300 times more dangerous than carbon dioxide.

In the past, energy companies have used the method to provide electricity and heat on site, but advances in cleaning technology now mean high quality biomethane gas may be the way forward for UK households in the near future.