The London Strategic Heat Main, a "mega" heat network project designed to provide low-carbon heating to 650,000 homes, is among the recipients of a £90 million government funding package announced on Tuesday. The project, already under development but subject to planning, will run under and alongside the River Thames, with ministers allocating £41 million towards its construction.
How the Thames heat network will work
Heat networks operate by recycling excess heat from sources such as data centres or factories and transporting it through a system of hot water pipes to multiple buildings at once. In its initial phase, the London Strategic Heat Main will transport hot water 15.5 miles each day using electric barges along the River Thames before a specially constructed tunnel underneath the river becomes operational.
The two proposed tunnels would be 2.5 metres in diameter and run from Belvedere to Westminster, with construction targeted for 2028 and heat supply from 2032. The initial phase will cross seven boroughs in the city: Bexley in south London, Greenwich, Lewisham, Southwark, City of London, Lambeth, and Westminster. Further extensions could later reach Barking and Dagenham in east London, Tower Hamlets, and Kensington and Chelsea.
Funding and job creation
Ministers said the project will help unlock about £5 billion of investment in London's heat networks and support skilled jobs in tunnelling, engineering, and river transport. The broader funding package, allocated through the government's "green heat network fund" and "heat network efficiency scheme," is expected to support the roll-out of these networks, reduce household bills, and create more than 2,000 jobs across all projects.
Energy minister Martin McCluskey said: "Clean power and clean heat benefit communities across our country. Building the infrastructure to deliver it is reindustrialising the UK and rolling out cutting-edge energy technology so families can benefit from lower bills, good jobs and energy security and for those already using heat networks, we are upgrading inefficient systems to make sure people get the high-quality, low-cost, reliable heating they deserve."
Other projects across England and Wales
Beyond the London Strategic Heat Main, money will go towards other smaller networks in the capital and extensions to existing networks in Bradford, West Yorkshire, and Solihull, West Midlands. In Bradford, 255 homes, a hospital, and seven schools and colleges will benefit from an extension of the original heat network, funded by a £9.7 million award. In Solihull, £3.9 million will go towards extending the existing network, which serves council buildings, a leisure centre, a theatre, and a college, to more buildings across the town.
A heat network development in London's Bexley and Greenwich areas, serving up to 100,000 homes when fully built, will receive £11.5 million. Another £11.4 million will go towards a system in London's Marble Arch area that will use water-source heat pumps to take energy from the London chalk aquifer to heat offices, homes, hotels, and businesses around Oxford Street.
Upgrades to existing networks
As well as building new low-carbon heat networks, the government has committed £13.3 million to upgrade 76 inefficient heat networks across England and Wales. Of this, £1 million will go to Manchester to improve the heating system for 130 residents in Cornwall Court in Gorton and Cundiff Court in Levenshulme. Work to upgrade systems serving 1,143 residents at Prospect House in Bermondsey, south London, and the Packington Estate heat network in Islington, north London, will receive £5.5 million. Improvements to systems at Eschol Court in Newport, South Wales, and Victoria Court in Abergavenny, Wales, will be backed by £374,900.
The pontoons storing water tanks for the London project could also be developed into "Thames Floating Gardens", with the potential to create new green spaces similar to the embankments built in the 19th century to cover the London Underground.
