UK utilities Thames Water, British Gas and Scotia Gas Networks have joined forces on a £2.5 million landmark project to produce renewable gas from human waste.
For the first time, the biomethane gas produced by a sewage works in Didcot, Oxfordshire will be fed into the gas grid to supply up to 200 homes.
An anaerobic digestion plant is being used to break down sludge, the solid part of sewage, from some of Thames Water’s 13.8 million customers to produce biogas.
The entire process – from flushing waste down the toilet to turning on the gas produced from it – takes around 20 days, according to British Gas’ parent company Centrica, which is operating the facility.
The project could be the first of many and has the potential to make a sizable contribution to the decarbonisation of the gas grid. National Grid estimates that renewable gas from all sources could make up 15% of the domestic market by 2020.
“We already produce £15 million a year of electricity by burning biogas from the 2.8 billion litres a day of sewage produced by our 13.8 million customers,” says Martin Baggs, chief executive of Thames Water.
“Feeding this renewable gas directly into the gas grid is the logical next step in our ‘energy from waste’ business.”
The model could be replicated across the whole country, he says, with every sewage works serving as a source of local renewable gas.
The six month project has been applauded by Secretary of State for Energy and Climate Change Chris Huhne.
“There are other similar projects across the country that are close to completion, so this is just the start of a new era of renewable energy,” he says.