The UK government says it is pumping £90 million ($119 million) into building and improving heat networks that redirect excess heat energy generated by a datacenter or factory and use it to warm homes or for other purposes. According to the Department for Energy Security and Net Zero (DESNZ), more than 750,000 homes will get cheaper heating as part of the scheme, which includes plans for a “mega heat project” that involves distributing hot water via a tunnel under the River Thames. The latter initiative is being backed by £41 million ($54 million) in funding and the department claims it will supply 650,000 London homes alone with "clean heat." This is designed to make the capital less reliant on gas - similar schemes have operated for decades in cities like Copenhagen, Amsterdam, Vienna and Berlin. The Register reported on a project back in 2023 that planned to connect 10,000 new homes in west London with nearby server farms to use their waste energy for heating. Given the glacial pace of progress on any UK project these days, the first question must be when this is likely to happen. The recently completed Thames “super sewer” project took 9 years to finish and cost about £5 billion ($6.6bn), leading The Reg to wonder whether tunnels for the heat project will ever actually be dug, and what the final price tag will be. In the absence of pipes in tunnels, the government says the hot water will initially be transported 25 kilometers (15 miles) along the Thames each day by electric barges from a waste plant near Bexley, a faintly ridiculous idea that has prompted inevitable outbursts of scorn from the usual highbrow commenters on social media. A spokesperson for DESNZ told us the £41 million funding is just for the barge part of the project, which is expected to start operating from 2028, while it hopes the tunnels will be operational in the 2030s. There is currently no information on how much that potion of the project will cost. There is also the question of whether using the waste heat from datacenters is really that efficient. It was previously noted by the Uptime Institute that the temperature is typically not high enough for applications including domestic heating, so a heat pump is required, which uses more energy. A 2024 report released by trade association TechUK claimed that while the latest fifth generation of heat network designs can operate with the lower temperature output from a computer shed, most operating in the UK are third-gen systems, which have lower energy efficiency and higher carbon intensity. Despite these doubts, a survey finds that about 60 percent of British people think planning permission for datacenters should be dependent on them supplying their excess heat to local homes and businesses, while 62 percent said they would be more supportive of a project in their area if it did commit to this. The polling was conducted by EnergiRaven, a firm advising on energy efficiency, which calls for all new server farms above 1 MW in capacity to include heat sharing infrastructure. As bit barn development continues to draw controversy, sharing waste heat could give operators another way to demonstrate their value to local communities, helping to build greater public support for new facilities, the firm claims. Alan Howard of tech analyst group Omdia commented: "District heating is certainly a win for any community, and for datacenters it may shine a positive light as some communities are hesitant to embrace them. What’s known so far… doesn’t reveal if the focus is on exploiting existing datacenters, which would [be] its own can of worms, or encouraging and supporting new datacenters to support the heating proposal." Howard added: "Of course, anything that might lighten the dependence on gas dependence is a win as well. It’s too early to call it a project, rather at this stage it is a concept. However, the government commitment is impressive and important to make such sweeping changes and upgrades to what sounds to be an aging and perhaps inefficient existing system." Omdia's Howard tells The Reg: "Obviously, of the many risk characteristics for such and undertaking there are a few that stand out: As a government led project the actual progress and timeline could be messy and long. The engineering for such a significant effort (“transporting hot water 25 km each day by electric barges “, not to mention the tunnels under the Thames) is certain to find a litany of challenges to overcome- While the funding sounds significant, real world experience in construction of seemingly exotic projects could easily balloon many time over." Other heat networks that can expect multi-million-pound investment from the DESNZ include an extension to an existing system in Solihull in England’s midlands, a project at Marble Arch in London serving offices, homes, hotels and businesses around Oxford Street, and another in London at Bexley and Greenwich that may serve up to 100,000 homes when fully built. ®
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