London Underground Goes Green: Solar Farm Initiative

EDF Renewables UK has signed a 15-year power purchase agreement (PPA) with Transport for London (TfL) to power London’s Tube network. This marks a significant step towards TfL’s goal of running the capital’s transport network on 100% renewable energy by 2030. 

A new solar facility will be built in Longfield, Essex, by EDF Renewables UK through its subsidiary Longfield Solar Energy Farm Limited. The PPA will help fund the construction of the 400MW Longfield Solar Farm for which EDF Renewables UK secured a development consent order (DCO) back in June 2023 from the Department of State for Energy, Security and Net Zero.

The 15-year Power Purchase Agreement (PPA) will see EDF’s subsidiary, provide around 80 gigawatt hours (GWh) of electricity annually to TfL, which is enough to power more than 29,000 homes, run the entire Tube network for a year or power both the DLR and Tram network for 15 years. Work on the new Longfield solar facility is set to begin in 2026, with full operation expected by the end of the decade, a potential contribution of around 400 GWh per year to the National Grid.

Approximately 20% of the new Longfield solar facility’s output will be supplied to TfL at a fixed price, protecting the transport operator, London’s largest single electricity consumer, from market volatility. The remainder of the solar output will be fed into the National Grid increasing its capacity and contributing to its wider decarbonisation goals. TfL has secured a fixed 15-year contract that not only locks in electricity prices but also protects it from energy market volatility.

Over its lifetime, the project is predicted to save more than 28,000 tonnes of carbon emissions, the equivalent of 33,300 one-way flights between London and New York. 

To help achieve its ambition of using 100% renewable source electricity across its operations by 2030 and further to the deal with EDF Renewables, TfL has launched a tender for a partner to help deliver additional purpose-built solar farms that could supply up to 64 megawatts of power which is around five per cent of the Tube’s total electricity needs through direct private wire connections.

The solar farm which covers 400 hectares of lower grade farmland near Chelmsford will not only support TfL’s decarbonisation but also help make the National Grid greener. It will provide around 400 GWh per year in total and deliver a biodiversity net gain of over 87 per cent which is eight times the legal requirement. The site will include tree and hedgerow planting, rewilding areas and wildlife corridors to boost local flora and fauna. Caring for nature and protecting the environment are key standards in TfL's contracts, in line with TfL's wider goals to be greener, more sustainable, and well-adapted to climate change. 

The project will also support new, green jobs during construction and operations bringing economic benefits to the wider region while also strengthening energy security by reducing the UK’s dependence on fossil fuels.

EDF Renewables’ CEO Matthieu Hue declared the partnership to be a “significant step forward” in powering essential public services with low-carbon energy.

“We are proud to partner with TfL on this PPA, which marks a significant step forward for the delivery of our Longfield solar farm. This agreement is built upon our shared commitment to sustainability and investing in clean energy, helping to power essential public services with low-carbon electricity and support the UK’s journey to net zero.”

The Mayor of London, Sadiq Khan, said: 

“This new agreement will enable us to power our transport network with clean, green, renewable energy and reduce TfL’s carbon emissions as we continue building a greener and better London for everyone.”

The announcement of the 15-year PPA with TfL coincides with the mayor’s launch of a new climate taskforce, to unlock the £75bn into the city needed to make the mayor’s ambitious target of net zero by 2030. The PPA was welcomed by both political and industry leaders. It aligns with the government’s ‘Plan for Change’ and places London as a leader for climate action. 

Industry leaders have declared support for the PPA. Rachel Cary of Energy UK said that the PPA shows 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”.

TfL is the UK’s biggest single electricity consumer, currently using 1.6 terawatt hours (TWh) per year which equates with about the same amount of electricity used by 420,000 homes or 12 per cent of homes across the capital.

TfL aims to source 70% of its electricity through future PPAs by 2030, with the rest expected to come from flexible green tariffs. The PPAs are part of the TfL’s broader energy purchase strategy to switch to 100 per cent renewable electricity supply by 2030.

UK’s Energy Minister Michael Shanks said the PPA was “very welcome news.”  Michael Shanks is set to deliver the keynote address at Solar Media’s Clean Power 2030 Summits, combining the UK Solar Summit, the Wind Power Finance & Investment Summit, and the Green Hydrogen Summit.

Day two of the UK Solar Summit will feature a panel discussion with representatives from TfL and the Energy Transmission Commission, on ‘Evolving Offtake Structures: Private Wire, PPAs & New Procurement Models for Large Energy Buyers Amid Fluctuating Power Prices’, which will cover emerging offtake structures and the future of procurement.

EDF Renewables has also signed a corporate PPA (cPPa) with UK state-owned transport operator Network Rail. The rail operator will benefit with an offtake of 64GWh of solar energy at a fixed cost over the 14 years the cPPA covers.

PPAs are well known for being a funding solution that offers developers a fixed income and revenue certainty for a solar plant. Last month, the UK and Ireland were the two countries to sign the highest number of renewable energy PPAs across Europe. According to the Swiss consultancy Pexapark, four PPAs were signed in the UK, covering a total volume of 113MW and two in Ireland covering 49.3MW. The biggest deal signed was between EDF and Network Rail. 

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. By giving EDFR the security to invest in new renewable energy sources in the UK, we are also creating new green jobs, improving the local biodiversity and wildlife, and stimulating the national economy. This will open doors to more public-private approaches to further accelerate the decarbonisation of GB’s grid.”

TfL is leading the way for large public bodies and how they can decarbonise their operations at scale with its new solar partnership and plans for direct grid connections. TfL are contributing to delivering cleaner air, lower bills, and new investment in UK renewables.