The City of London Corporation has launched a GBP4.3 billion (US$5.3 billion) competitive process to find a private developer to design, build, and operate a low-carbon heat network for the financial district known as the Square Mile.

Updated modelling indicates that the network could eventually provide heating to approximately 1,200 buildings, with the River Thames serving as a key source of strategic heat. Under the 42-year concession, a single private-sector partner will establish and operate a special-purpose vehicle responsible for delivering the project from design and development through construction and long-term operation. Recent assessments have identified approximately 1,200 buildings that may be required to connect under forthcoming heat-network regulations. Together, these buildings are estimated to generate an annual heat demand of around 1,000 GWh, necessitating approximately £1.26 billion (US$1.7 billion) in heat-network capital investment as part of a broader system whose total value over the concession period is now projected to exceed £4 billion. Strategic analyses also highlight the River Thames as a critical asset for both heat supply and distribution within the City.

In the near term, potential solutions include the use of thermal barges stationed along the river, with Swan Lane pier identified as the preferred initial site for a floating installation. Additional mooring locations have also been identified and could be brought into service as demand increases or supply is rolled out in phases. Over the longer term, the City is expected to draw significantly on three large-scale heat sources: surplus heat from data centres in Tower Hamlets; recovered heat from Thames Water’s Beckton Sewage Treatment Works, which releases approximately 1,029 GWh annually; and substantial heat supply from Cory’s Riverside Energy Park in Belvedere. Riverside Energy Park’s current annual heat output of 917 GWh is expected to rise to approximately 3,000 GWh once the Riverside 2 facility becomes operational. Combined output from Riverside 1 and 2 could meet the full heating demand of the Square Mile and potentially cover around half of Westminster’s annual requirements. Cory already manages the City’s residual waste, transported by barge from Walbrook Wharf, creating an established operational relationship that underpins the emerging heat-network strategy.

The City’s procurement schedule sets January 26, 2026, as the deadline for applications, followed by interim tenders in March and final submissions in June, with the preferred bidder due to be announced on 5 November 2026. Arup is acting as procurement adviser for the process.