Transport for London (TfL) has marked a major milestone in its decarbonisation journey, with its Therapia Lane depot – home to London Trams – becoming the organisation’s first operational site to eliminate fossil gas usage. The depot has undergone its most significant upgrade since opening 27 years ago, introducing a fully electric heating system and on-site solar generation.
The transformation is part of TfL’s wider commitment to reducing its environmental impact and preparing its infrastructure for a low-carbon future. The overhaul replaces traditional gas boilers with a combination of electric heat pumps and infrared panel heaters, which focus warmth where staff need it most. This targeted approach minimises heat loss and improves energy efficiency compared to conventional systems. Hot water delivery has also been modernised with on-demand electric heaters.
To offset the additional electricity demand, the depot now boasts 1,800m² of rooftop solar panels, generating 187 kWp of clean energy. Alongside improved insulation and LED lighting, these measures will cut carbon emissions by around 183 tCO₂e annually – equivalent to the footprint of a modern housing development – while creating a brighter, more comfortable working environment.
Work on the depot was carried out in a live operational setting, providing valuable lessons for decarbonising other TfL sites and rail depots nationwide.
Mete Coban, Deputy Mayor of London for Environment and Energy, hailed the achievement:
“It’s fantastic news that Therapia Lane depot has become TfL’s first depot to remove fossil fuel gas usage by upgrading its heating system and installing hundreds of new solar panels.
This green transition will help improve energy efficiency and save money, showing that sites like this have an important role in reducing the impacts of climate change.
The Mayor and I will continue to work with partners to ensure we can deliver a greener and fairer London for everyone.”
Lilli Matson, TfL’s Chief Safety Health & Environment Officer, added:
“The decarbonisation of Therapia Lane depot, one of the busiest operational spaces in south London, shows that it is possible to eliminate the use of fossil fuels from large, complex buildings as it runs on fully electric infrastructure. It is vital we invest now in making our operations cleaner and greener to reduce our emissions and build the next generation of green skills, further supporting the Mayor's ambition of a carbon neutral capital by 2030.”
The project is also helping to close the green skills gap. TfL and its supplier, Vital Energi, are investing in apprenticeships and graduate placements focused on net-zero delivery.
Kyrel Rose, a Building Services Engineering apprentice, shared his experience:
“Whilst working on the Therapia Lane trams depot project, I gained first-hand exposure to a live rail infrastructure environment, whilst gaining a better understanding of how design, construction, and operational requirements come together on a large transport project. My awareness of site safety procedures has improved and how works are planned around an active operational environment. It also gave me valuable experience linking drawings and design intent to what is installed on site, which helped reinforce engineering principles in a real-world context.
The site tour was a personal highlight, particularly seeing the job come towards completion, how much work has been put in to meet deadlines and the vast change there has been.”
The upgrade was part-funded by the Government’s Public Sector Decarbonisation Scheme and Low Carbon Skills Fund, delivered by Salix and the Department for Energy Security and Net Zero. These schemes are also supporting similar upgrades at TfL’s Palestra House HQ, where smart sensor technology and heat pumps are expected to cut emissions by more than 1,500 tonnes annually. Plans are in place to roll out comparable technology at offices above stations including Aldgate, Baker Street, Oxford Circus and Victoria.
TfL’s wider decarbonisation strategy includes a landmark Power Purchase Agreement to build a solar facility generating 80 GWh of electricity per year – enough to power the DLR and Tram networks for 15 years. A private wire tender is also underway to supply zero-carbon electricity directly to the London Underground, potentially delivering up to 64 MW of clean energy.
Beyond energy, TfL is improving biodiversity across its network, introducing 390,000 m² of wildflower verges and expanding urban greening initiatives to tackle flooding and enhance resilience.
Image and video credit: TfL
