Global resource management company, Veolia, is helping Southern Water derive even more of its power from sewage. The company is installing new combined heat and power (CHP) engines at three of Southern Water’s treatment works - Budds Farm and Fullerton in Hampshire and Gravesend in Kent. The work will save around 3,600 tonnes of CO2 emissions each year and is part of Southern Water’s wider project to generate even more renewable energy by upgrading CHP units at five of its sites.
Southern Water Services is the provider of water and wastewater services for Kent, Sussex, Hampshire and the Isle of Wight. Routed through a sewer network of 39,000km, 718 million litres of wastewater get treated and recycled at the company’s 368 treatment works every day.
Commenting on this latest CHP application, John Abraham, Veolia’s Chief Operating Officer - UK Municipal Water & Ireland said, “Recent estimates show that biogas from the sludge resource could deliver an estimated 1,697GWh each year - enough electricity to power over half a million homes. This latest extension of the use of CHP by Southern Water clearly demonstrates its commitment to further the sustainability of the water industry.”
Martin Ross, Southern Water Energy Manager, said: “We currently generate 17% of our electricity from 16 CHP sites. The capturing of biogas is a double win because not only do we collect free fuel but we also prevent the release of methane which has a global-warming potential 25 times more potent than carbon dioxide.”
Biogas, captured by anaerobic digestion from the wastewater treatment processes is used as a fuel, and will provide the electricity needed to power the wastewater treatment operations, with the surplus being fed to the Grid. The heat recovered from the CHP units is fed to the AD process to speed up the bacterial digestion of organic matter and biogas output.
Around 190 UK wastewater sites now produce biogas to generate electricity which is used on site or exported to the national grid. Today, the potential power from human sewage in the UK could now keep around fourteen million LED/LCD TVs or ten million game consoles running constantly.