The biggest heat pump projects in Britain
Some of 'em are real whoppers, mate!
In recent weeks, I have been on a search. A quest to find the biggest heat pump-powered projects in Great Britain. Last year, for BBC News, I wrote about the exploding demand for giant heat pumps – an increasingly popular technology in European district heating systems. Back then, I was trying to find the biggest heat pump in the world.
But all the most impressive projects were happening in continental Europe rather than the UK. This may remain true, however, that is not to say that there aren’t some significant heat pump-powered networks in the pipeline in Great Britain.
So, here you go – the biggest projects in Blighty involving heat pumps in some form that I could find, listed roughly in order of scale. I’ve selected incomplete projects and only those greater than 20 gigawatt hours in terms of projected annual heat demand. Some of them are whoppers.
Did I miss any? Let me know! I did exclude some schemes based on lack of progress or very limited information confirming their scale and scope, which may explain some omissions. Plus, see below for a note on Wales and Northern Ireland.
Thanks to Gemserv/Triple Point Heat Networks for helping to confirm several details for this story.
Big caveat: many of the projects listed below are very early stage and the expected heat output may be subject to change. Not all projects may develop as planned!
Exeter Energy Network (100+ gigawatt hours, GWh)
This is not solely a heat pump-based system – it will also include gas-fired boiler backups. However, the idea, developed by energy firm 1Energy, is to build a network featuring 11.12 megawatts of air source heat pumps, 9.57 megawatts of water source heat pumps, plus thermal stores. This collection of heat sources would have an estimated average annual carbon intensity of 59 grams of carbon dioxide equivalent per kilowatt hour. That’s roughly about a quarter as polluting, in terms of carbon, as the average domestic gas boiler. Though I’m not sure how carbon intensity will vary across a year for a project of this size.
The University of Exeter will be the biggest customer in terms of heat supply, requiring 28.38 GWh per year. Currently still at the design stage, this project has received significant funding.
I must note that 1Energy is also planning a similar-sized scheme, for Milton Keynes, with an annual projected heat demand in excess of 110 GWh. This would use a water source heat pump and gas boilers.
Edinburgh (70+ GWh)
Although the plan to use waste heat from the University of Edinburgh’s supercomputer centre is at a fairly early stage, it deserves a mention here because of its potential scale. In this scheme, heat from supercomputers would be used to warm mine water. This water would then be warmed further by heat pumps for use in domestic properties. Output of 70 GWh is theoretically possible today but – get this – that could rise to 272 GWh annually once the UK Government’s new exascale supercomputer is installed at the university in the coming years.
Bradford Energy Network (67 GWh)
This project, currently under construction, is very much in the same vein as the Exeter Energy Network mentioned above and is also the work of 1Energy. This one will also feature backup gas boilers. However, there will also be air source heat pumps with a capacity of around 8 megawatts. These will account for around 87% of the heat supply, according to documentation on the UK government’s website. “We aim for at least 80% of our heat to be coming from low carbon sources on each heat network, increasing to 100% over time,” a spokesman for 1Energy tells The Reengineer.
Stoke-on-Trent (65 GWh??)
It’s very early days for this one. A Memorandum of Understanding was published in 2021, which suggests that the Stoke-on-Trent network would involve the drilling of two 3.8 kilometre-deep geothermal wells in the Etruria Valley. Heat pumps could in theory be used to step up the heat extracted from these wells and supply nearby homes, though I haven’t been able to find any hard details about how it would all come together, or confirmation of the expected annual output. A spokesman for energy firm SSE, one of the entities behind the project, says that SSE is working with Stoke-on-Trent Council on an earlier phase of the project at present, which does not include a geothermal component.
Brent Cross Town (50 GWh)
Another fairly nascent project, this is nonetheless a sizeable one, as far as initial plans go. It would supply 6,700 homes and 3 million square feet of retail and commercial space with both heating and cooling. A spokesman for Vattenfall, an energy company behind the scheme says total energy output is currently estimated to reach “around 50 GWh”. He also says Vattenfall’s latest modelling suggests that a combination of carbon-dioxide based air source heat pumps and a water source heat pump would be able to meet 98% of demand, with an electric boiler helping out at peak times.
The water source heat pump would use the cooling network return as its heat source adds Vattenfall’s spokesman.
Paisley Central (50 GWh)
Renfrewshire Council is working on a decentralised heat network in which heat pumps at each building will step up heat from an ambient loop. It will reportedly meet a hefty projected heat demand of nearly 50 GWh, though a spokesman for Renfrewshire Council says this is an estimate that is “still to be determined”. Potential connections on the network include the University of the West of Scotland, the Royal Alexandra Hospital and the Paisley Museum and Art Galleries.
Liverpool (45 GWh)
With a water source heat pump system, this could end up rivalling the Paisley Central project in terms of heat output. The initial phase will aim for 20 GWh annually and will supply 6,700 homes in the Liverpool Waters development alongside other domestic and commercial properties nearby. The energy centre is due to be completed this year, according to reports. The project has planning permission that could allow it to eventually achieve output as high as 45 GWh per year.
Lancaster University (39 GWh)
The university is currently undertaking a programme to upgrade its buildings, for example by adding insulation, which will enable heating systems in those buildings to run on lower flow temperatures. The idea is to make campus properties “heat pump ready” and this work comes in advance of a new energy centre that will house air source heat pumps and an 11.5 megawatt solar farm.
Construction work on the extension of the existing heat network began in November, a spokesman for Lancaster University tells The Reengineer. The extension, featuring 6.5 kilometres of additional pipework, will enable the network to supply 95% of the university’s buildings (an increase from 65%). The project is expected to be completed in Spring 2027. “That heat will all come from heat pumps and 1 megawatt of electric boiler,” a university spokesman tells The Reengineer.
Barnsley (38 GWh)
This is a plan to use mine water (2.3 megawatts) and air source heat pumps (6 megawatts) to supply an initial 20 buildings in Barnsley town centre. The project was awarded £12.6 million of funding this year and further investment could allow the network to expand and supply all homes and businesses in Barnsley by 2050. Construction is scheduled to begin next year.
South Westminster Area (35 GWh)
In November, news broke about the South Westminster Area Network (Swan), which will use waste heat or the River Thames to supply buildings including, potentially, 10 Downing Street and the Houses of Parliament.
“The first phase of Swan will need at least one large industrial scale heat pump, and as the network grows, more large industrial scale heat pumps will be added,” a spokesman explains to The Reengineer. “We are currently investigating which heat sources will be best.”
Output of 35 GWh would be enabled by the first phase and future phases could increase this output further, though by an as-yet undisclosed amount.
West Bromwich Heat Network (35 GWh)
This is listed on the government’s website as a heating network that will use heat pumps connected to a sewer source, in order to harvest ambient heat from wastewater. Sandwell Metropolitan Borough Council approved the business model for the heat network last year. The initial “heat on” date is June 2026 and planned customers due to be connected the following year include Sandwell College and Sandwell General Hospital.
Greenwich Peninsula (32 GWh)
I’ve found references to multiple large scale heat pump-powered networks in and around Greenwich, including one that would supply Greenwich University and the National Maritime Museum. However, details are scant as to how these would all come together. One project in the area that has received funding, though, is the Greenwich Peninsula district heating network, which would use a large air source heat pump on the roof of an energy centre to supply 9,000 homes. The Reengineer has contacted the Royal Borough of Greenwich for comment regarding other potential heat network projects in the borough.
Granton Waterfront, Edinburgh (30 GWh)
According to the Scottish government’s website, this system would use a sewer source heat pump to supply 3,000 homes and non-residential properties including a primary school and medical centre. Vattenfall was appointed as a project partner in November 2023.
Silvertown Quays, East London (27 GWh)
An interesting example of a decentralised heat pump network from E.ON, where smaller air, water and ground source heat pumps will harvest energy from the environment to supply various buildings. Excess heating or cooling will be piped into the wider so-called “Ectogrid” network that links up various properties, ensuring that this energy does not go to waste. The project has received significant funding and is currently under construction.
Hull (25 GWh)
This scheme, which is currently seeking a contractor, would use heat pumps to step up waste heat from industrial sources. It would also include backup gas boilers.
A note on Wales and Northern Ireland
I decided to write a story about “Britain’s biggest heat pump projects” because I realised that all the ones I could find are currently unfolding in Great Britain, and only England and Scotland at that.
I live in Belfast so this is certainly not personal bias! What I can report, though, is that the Geo Energy NI initiative is currently exploring geothermal and ground source heating opportunities in the region. Belfast City Council appear to have a small team working on the concept of a heat network for the Northern Irish capital. In an online document (PDF), the Council estimates that such a network could meet 100% of the Council’s emissions reductions targets by 2050. Similarly, Swansea Council has also discussed (PDF) heat pump-driven district networks, for example.
Update: This story has been edited post-publication to include Brent Cross Town, following details shared by Vattenfall.
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