UK: Transport for London has appointed SSE Energy Solutions to build and operate solar installations to provide zero-carbon electricity directly to the London Underground through a private wire scheme, bypassing the National Grid’s centralised sources and Distribution Network Operators and reducing pressure on central grids.
TfL said the four-year agreement renewable for a further four years, announced on March 3, was one of the first private wire schemes for an urban transport network.
SSE Energy Solutions will work with TfL to identify locations near the network where it can build ground or rooftop solar facilities. These are expected to deliver up to 65 MWh per year, equivalent of around two-thirds of the estimated annual consumption of the Victoria Line. TfL said the use of solar power offered the potential to save more than 27 000 tonnes of carbon over 25 years, the equivalent of almost 32 900 flights between London and New York. There might also be opportunities to feed other parts of the TfL estate, such as depots.
The agreement will guarantee renewable power at a fixed price, protecting TfL against market volatility, while also contributing to its security of supply. In the longer term, the scheme could potentially generate additional financial savings through bypassing some of the costs associated with delivery of power through the National Grid.
TfL is London’s largest single electricity consumer at 1·6 TWh per year, procured at a cost of £350m in 2024-25. Its electricity procured directly from the grid currently equates to a total of 321 000 tonnes CO2e per year, or 41% of TfL’s operational carbon emissions.
TfL is aiming to transition to using 100% renewably sourced electricity by 2030. It plans to obtain up to 70% of the electricity it needs through Power Purchase Agreements, and has already awarded EDF Renewables UK a 15-year PPA to supply 80 GWh/year from a solar farm at Longfield in Essex. The remainder of TfL’s electricity will mainly be procured through a flexible green tariff.
