Thames Water Deephams

Having qualified onto their biomethane framework in 2020, we were then awarded the contract to design, build, maintain and operate (for 3 years post construction) Thames Water’s first full scale biomethane plant at the Deephams sewage treatment works site. The plant is designed for a maximum 1,150 Nm³/hr flowrate of biogas, with a maximum biomethane injection rate to the Cadent medium pressure grid of 825 Sm³/hr.

Despite the impacts of the COVID pandemic, the project was delivered on schedule and Thames were hence able of register with the RHI scheme ahead of its pending closure. The SGN CS Team worked with Thames Water to ensure the biomethane plant could be controlled and operated in conjunction with the relatively new CHP plant that was already operating at the site. The design solution allows Thames Water to flex their biogas utilisation based on prevailing conditions, maximising the carbon and financial benefits to the greatest possible extent.

The Deephams biomethane plant is now playing a key role in helping Thames Water reach its 2030 net zero target. In its first year, it achieved an average output of 550 Sm³/hr of biomethane with 97% operational availability—enough to heat 4,250 homes in Enfield.