Transport for London (TfL) has signed a major green energy deal with EDF Renewables UK to supply the Tube with clean electricity from a new solar farm in Essex, marking a significant step towards its goal of running the capital’s transport network on 100 per cent renewable energy by 2030.
The 15-year Power Purchase Agreement (PPA) will see EDF’s subsidiary, Longfield Solar Energy Farm Limited, provide around 80 gigawatt hours (GWh) of electricity annually to TfL—enough to power more than 29,000 homes or the entire Tube network for a year. Construction of the new Longfield solar facility is set to begin in 2026, with full operation expected by the end of the decade.
The solar farm, covering 400 hectares of land near Chelmsford, will not only support TfL’s decarbonisation but also help green the National Grid. It will provide around 400 GWh per year in total and deliver a biodiversity net gain of over 87 per cent—eight times the legal requirement. The site will include tree and hedgerow planting, rewilding areas and wildlife corridors to boost local flora and fauna.
As the UK’s largest single electricity consumer, TfL currently uses 1.6 terawatt hours (TWh) annually—about the same as 420,000 homes. Under its long-term energy strategy, TfL aims to source up to 70 per cent of its power through direct PPAs, with the remainder via green tariffs, helping to shield operations from market volatility and price shocks.
The PPA will also support new green jobs during construction and operations, while bolstering energy security by reducing reliance on fossil fuels. EDF Renewables’ CEO Matthieu Hue described the partnership as a “significant step forward” in powering essential public services with low-carbon energy.
Lilli Matson, TfL’s Chief Safety, Health and Environment Officer, said the project marks a “new green era” for the Tube, adding: “We are using our purchasing power to make public transport the most environmentally sustainable choice Londoners can make.”
TfL also announced it has launched a tender for a partner to help deliver additional purpose-built solar farms that could supply up to 64 megawatts of power—around five per cent of the Tube’s total electricity needs—through direct private wire connections.
The announcement was welcomed by political and industry leaders alike. Energy Minister Michael Shanks MP said the agreement supports “local jobs whilst reducing emissions” and aligns with the government’s Plan for Change. The Mayor of London, Sadiq Khan, hailed the move as further proof that London is leading the way in climate action.
The deal comes as the Mayor launches a new climate finance taskforce to help unlock the £75 billion of private investment needed to achieve net zero in the capital by 2030.
Rachel Cary of Energy UK said the PPA demonstrates how “collaboration can help power London’s vital public transport network sustainably”, while Rollo Maschietto of the Renewable Energy Association called it “a blueprint for how the public sector can get behind the energy transition while supporting green jobs and strengthening energy security”.
With its new solar partnership and future plans for direct grid connections, TfL is setting the pace for how large public bodies can decarbonise operations at scale—while delivering cleaner air, lower bills and new investment in UK renewables.
