Thames Water Mogden
Overcoming challenges through engineering excellence
Green Gas Solutions’ scope included:
- Advisory services.
- Design development.
- Construction & commissioning.
- Operation & maintenance services.
Project Details
Mogden STW is one of Thames Water’s Tideway treatment works and among the UK’s largest wastewater AD sites. After the successful delivery of the biomethane gas-to-grid plant at Deephams STW in 2022 and, in line with their net zero strategy, Thames opted to add a biomethane gas-to-grid plant at Mogden during AMP7.
As a framework provider of gas-to-grid solutions for Thames Water, and following the resounding success of the Deephams project, the SGN Green Gas Solutions team was appointed to deliver the scheme at the start of 2022. With neighbours on all boundaries and an ever-increasing local population, the Mogden STW site is especially constrained for space. The design development and delivery of the gas-to-grid project was further complicated by a major treatment process upgrade project happening concurrently at the site. The layout, plant configuration and plant control would all need to consider construction, interim and legacy phase site arrangements. SGN developed an elongated design for the main plant to work given space constraints. The plant layout had to accommodate HV/LV transformers to supply the membrane upgrader and associated ancillaries. The SGN team positioned the ROV on the Mogden site’s external boundary and then designed and installed a 315mm diameter PE export pipeline over a complex 1.2km route crossing a major arterial road in London (A316) into a medium pressure (MP) system adjacent to Twickenham Stadium. Although convoluted, this connection option guaranteed year-round export capacity.
After a challenging but successful implementation phase, commissioning commenced in November 2023, with the first green gas being injected in December. From January the plant effectively commenced commercial operation, outputting sufficient green gas to supply over 4,000 local homes, offsetting 8,000 tonnes of fossil carbon emissions each year. The project has further shown how gas-to-grid technology can be rapidly deployed and fully integrated in a high-profile municipal wastewater treatment context.
Green Gas Solutions’ expertise ensured:
- A carefully optimised layout to make the most of the space available.
- Design and installation of a 315 mm diameter PE export pipeline over a complex 1.2km route with many high-profile stakeholders.
- Operational flexibility and integrated control, including HV and Power Management System scope.
- Implementation of a state-of-the-art cyber security solution, allowing remote monitoring and control without compromises.
See what our clients say about working with us
We recently built Thames Water their second commercial scale biomethane plant at the Mogden works in Twickenham.
Despite many challenges, we delivered the scheme successfully and are now running the plant. Eugene Cotterall, Head of Programme Delivery in Thames’ Major Projects function, was kind enough to share his experiences of working with Green Gas Solutions.