British homes will be using gas made from human sewage for the first time today as a pioneering £2.5m scheme in Oxfordshire goes live.
Ultimately, the Didcot sewage works could produce enough low-carbon gas to supply 200 local homes, thanks to the joint venture between Thames Water, British Gas and Scotia Gas Network.
Thames Water already produce some £15m-worth of electricity each year by burning gas made from the 2.8 billion litres of sewage produced by the company’s 14 million customers. To turn feed the gas directly into the grid for use by consumers is simply “the logical next step”, according to Martin Baggs, the Thames Water chief executive.
The gas is produced by warming up “sludge” – the solid part of the sewage – for anaerobic digestion by bacteria, which breaks down any biodegradable material and produces biogas.
The “end to end” process from lavatory to gas grid takes around 20 days and the average person produces the equivalent of 30 kilos of dried out sewage-sludge per year. If the sewage from all 63 million people could be used to generate renewable gas, it would meet the demands of 200,000 homes, according to British Gas.
Chris Huhne, the Energy Secretary, endorsed the scheme yesterday. “This is an historic day for the companies involved, for energy from waste technologies, and for progress to increase the amount of renewable energy in the UK,” he said. “It’s not every day that a Secretary of State can announce that, for the first time ever in the UK, people can cook and heat their homes with gas generated from sewage.”