Next stop, net zero: Biogas boiler saves enough diesel to circle the earth 350 times

A multi-thousand-pound project at Chertsey’s sewage works to convert a diesel boiler to run on renewable biogas means the town’s waste is now being treated without the use of fossil fuels, cutting down on carbon emissions and noise pollution for residents.

Thames Water, which owns and runs the site, is eliminating more than 70,000 litres of diesel every month by using the green gas, a by-product of the sewage treatment process, as it looks to reach net zero carbon emissions across all operations by 2030. It will save enough fuel over a year to drive around the world 350 times, while also hugely cutting the number of tankers travelling to and from the works to deliver diesel.

The latest project in Chertsey has been completed in recent weeks, at a time when renewable energy, including the phasing out of gas boilers in UK homes, has been high on the national agenda and ahead of the upcoming COP26 conference.

The £700,000 scheme at the Surrey works is the latest in a roll-out which also covers other Thames Water sites in London and the Thames Valley. Three-quarters of the company’s boilers now run on biogas, with Thames Water aiming to convert all sites by the end of 2025.

Matthew Gee, Thames Water’s energy & carbon strategy & reporting manager, said: “This exciting project has enabled us to eliminate the use of fossil fuels at our Chertsey site, which is great news for the environment as well as our customers, who we know want us to provide value for money in a sustainable way. The project will save us around £500,000 in fuel costs, allowing us to keep customer bills low.

“Running all our sludge treatment processes on biogas is an essential part of our carbon strategy; shaping the future by driving operational emissions to net zero by 2030.

“We’re determined to change and lead the future of energy transition by transforming the way we create and use energy, before becoming the first in our industry to go beyond net zero by 2040 to be carbon negative.”

The new biogas boiler is essential to running Chertsey’s thermal hydrolysis plant, which itself creates the renewable biogas, and was the first in the UK when it was commissioned in 1999.

In June, Thames Water announced it is committed to leading the future of energy transition by transforming the way it creates and uses power to become carbon neutral by 2030, having cut emissions by almost 70 per cent since 1990.

The UK’s largest water supplier, which has been producing renewable energy at Mogden sewage works in London since the 1930s, is also aiming to protect the planet and its 15 million customers water supply for the future by becoming carbon negative by 2040.

The company’s comprehensive plan includes reducing the use of fossil fuels across the business, harnessing renewable energy sources from waste, solar power and heat recovery schemes, and working with sustainable suppliers and partners.

See the full roadmap – which will continue to be updated towards the 2030 milestone – here.