London Strategic Heat Main gets go-ahead with £41.6m of govt funding

RHN Developments’ London Strategic Heat Main has become the first beneficiary of funding from the Government’s Green Heat Network Fund’s Strategic Heat Main category for heat distribution at scale.

The London Strategic Heat Main will distribute heat across more than 25km of tunnels in central London. The initial transmission trunk is intended to cross seven Boroughs: Bexley, Greenwich, Lewisham, Southwark, City of London, Lambeth, and Westminster. Further transmission branches are under consideration for Barking and Dagenham, Tower Hamlets and Kensington and Chelsea.

This is the first UK strategic heat main on the scale of European systems, which have operated in cities like Copenhagen, Amsterdam, Vienna and Berlin, as well as Asian cities like Seoul.

RHN, a Cory Group company, has secured £53.14m, comprising the Heat Main and the Riverside Heat Network, which will receive £11.5m of construction funding.

David Carter, Managing Director – Heat at Cory Group, said:

This award is a major vote of confidence in heat transmission as part of the UK’s future energy infrastructure. The London Strategic Heat Main will allow us to capture surplus low-carbon heat and move it to where it is needed, helping to cut carbon, improve energy security and support new investment across the capital. By delivering heat by barge while the permanent tunnel is developed, we can start serving Londoners sooner and demonstrate a model that could be replicated in cities across the UK.”

The GHNF noted that the Heat Main is designed to make London’s heating system less dependent on gas and help protect consumers from future gas price shocks. When Ukraine was invaded, energy costs in the UK rose by c.250%, it said, whereas in Copenhagen, which taps into regional heat sources connected by strategic heat mains, heating costs only rose by around 20%.

By replacing gas heating, the Heat Main would reduce carbon emissions by around 95%, while eliminating boiler NOx emissions at source, the Fund said.

According to Local Area Energy Plans, the district heating networks which the Heat Main would serve would unlock more than £5 billion of local investment. Meanwhile, the tunnel construction would also support highly skilled tunnelling jobs, drawing on UK skills supported by legacy tunnelling projects, such as Crossrail and Thames Tideway, the Fund added.

While the tunnels are under construction, heat will be supplied by electric barges, which will carry heated water up the Thames and deliver it to large, insulated hot water tanks housed in new pontoons. This will allow heat to reach central London from 2028. The project is exploring configuring these pontoons as “Thames Floating Gardens”, with the potential to create new spaces and greenery, like the Thames embankments built to house the London Underground and major sewers in the 19th century.

Ken Hunnisett, Head of Clean Heat at Green Heat Network Fund investment partner Triple Point, said:

We’re delighted to announce the detail of these two awards from the Green Heat Network Fund. The London Strategic Heat Main is a genuinely game-changing project for London and the mobile heat barges are a key enabler of it. With the potential to deliver low-carbon heat from 2028, ahead of the tunnel’s construction, the barges significantly reduce demand-side risk, giving developers and investors the confidence to commit to local network growth now. Delivered well, the London Strategic Heat Main won’t just transform how the capital heats itself, it will be an exemplar for strategic transmission networks across the UK.”

The Fund added that Cory is a London business which has invested over £900m in infrastructure along the Thames in the last three years.  As well as owning and operating the anchor heat source: Europe’s largest single-site energy-from-waste facility on the Thames in Bexley, Cory already operates a fleet of over 60 barges, moving waste and by-products along the river.

Other GHNF supported projects, including Hemiko’s Waterloo and Southbank heat network, and L&Q’s Barking Riverside project, are already working with Cory to explore how additional capacity from the system could support these developments through localised long-term supply agreements and pricing arrangements.

The Riverside Heat Network

The Riverside Heat Network is a collaboration between Vattenfall and Cory with the potential to serve tens of thousands of homes, including existing social housing and new homes. The Network is designed to operate independently, while remaining capable of connecting to the London Strategic Heat Main in the future.

Toby Heysham, CEO, Hemiko, said:

Strategic heat transmission is the missing piece of the puzzle for unlocking cheap, low-carbon heat at scale. There is so much wasted heat in towns and cities, the challenge is getting it to the right place and then into a useable format for customers. Projects like the LSHM have the potential to transform how cities across the UK drive down heating cost. For network developers like Hemiko, connecting into a major source of low-cost heat will allow us to build and expand local heat networks more quickly, bringing cheap, local, secure heat to more and more buildings.”