The City of London Corporation has launched a £4.3bn procurement to secure a single private development partner to design, build, finance and operate a flagship low‑carbon heat network across the Square Mile. The 42‑year concession will be delivered through a Special Purpose Vehicle, with the City taking no economic return but retaining a “golden share” to protect governance and key strategic decisions.
New modelling indicates the network could ultimately serve around 1,200 buildings, with a combined annual heat demand of roughly 1,000 GWh. Recent studies suggest many of these buildings could be mandated to connect under emerging heat‑network regulations, driving an estimated £1.26bn of heat‑network CAPEX within a wider system value now expected to exceed £4bn over the life of the concession.
The River Thames is central to the technical strategy, both as a primary heat source and as a corridor for major west–east trunk mains and branch connections along the waterfront. Early‑phase options include thermal barges moored on the river, with Swan Lane pier identified as the preferred initial location, and additional mooring points mapped for phased deployment as demand and supply ramp up.
In the longer term, the City expects to rely on three industrial‑scale low‑carbon sources: waste heat from data centres in Tower Hamlets, rejected heat from Thames Water’s Beckton Sewage Treatment Works – which currently sheds around 1,029 GWh a year – and heat from Cory’s Riverside Energy Park in Belvedere. Riverside’s current 917 GWh annual heat output is forecast to rise to about 3,000 GWh once the Riverside 2 plant is completed, theoretically sufficient to meet the entire Square Mile load and supply up to half of Westminster’s annual demand.
Cory’s expansion gained momentum in August when its Heat Main 1 scheme, a strategic cross‑London pipe linking Riverside to central networks, was designated a Nationally Significant Infrastructure Project, bringing it into the Development Consent Order regime and potentially accelerating planning. Cory already handles the City’s residual waste by barge from Walbrook Wharf, providing an established operational interface that underpins the proposed integrated waste‑to‑heat model.
The procurement will follow a five‑stage competitive procedure. The City has set an application deadline of 26 January, with interim tenders due in March, final tenders in June and a preferred bidder scheduled to be named on 5 November 2026, ahead of contract signing targeted for the same month. Arup is advising the City of London Corporation on the procurement strategy and technical scope.
