Unlocking the hidden potential of data centres through heat zoning. Success, requires a shift in perspective.

As AI, cloud usage and digital services continue to drive demand for data centres, much of the conversation to date has centred on one issue, electricity. While these facilities are often viewed as major energy consumers, they also produce something of increasing value to the UK's net zero ambitions, heat.

Every day, data centres generate significant amounts of waste heat as servers are cooled. Historically, most of this heat has been discharged into the atmosphere, despite the fact that heating buildings accounts for a substantial proportion of the UK's carbon emissions. The opportunity to connect these systems is becoming increasingly immediate with the Energy Act became law in October 2023, draft heat-network zoning maps were published in September 2024, and detailed zoning regulations are being finalised in 2026, with the first zones expected to begin development later this year. This could enable data centres to play a much bigger role in the UK's wider energy system.

Heat network zoning identifies areas where heat networks are likely to be the most cost-effective and low-carbon way of supplying heating to buildings. Instead of each building relying on its own heating source, heat can be generated or recovered centrally and distributed through a shared network. For data centres, this presents an opportunity to rethink their role. Rather than being viewed solely as consumers of electricity, they can become suppliers of a valuable energy resource, providing reliable, heat to nearby homes, hospitals, universities and commercial developments.

As the demand for digital infrastructure continues to rise, particularly with the rapid growth of AI, it is increasingly important that data centres are considered as part of a connected energy ecosystem rather than standalone assets.

The technology to recover waste heat has existed for many years, yet relatively few projects have been delivered in the UK. The reasons are rarely technical alone. Heat cannot be transported over long distances as efficiently as electricity, meaning there needs to be a suitable heat demand close to the data centre. In many cases, developments have been built without nearby heat networks, while the commercial incentives to invest in new infrastructure have been limited. As a result, vast amounts of usable thermal energy have simply gone to waste. 

Today, however, the landscape is changing. Heat network zoning, alongside greater policy support and growing pressure to decarbonise buildings, is encouraging developers and local authorities to think differently. Increasingly, waste heat recovery is being considered during the earliest stages of site selection and masterplanning, rather than as an afterthought.

Countries such as Denmark and Sweden have shown what is possible when energy infrastructure is planned holistically. There, industrial waste heat, including that from data centres, is routinely captured and fed into extensive district heating networks that serve entire communities. The difference is not simply technology. These countries have invested in district heating infrastructure for decades, supported by long-term policy certainty and coordinated planning.

The UK starts from a different position, with heat networks serving only a relatively small proportion of buildings. This means new infrastructure often needs to be developed alongside new data centres, requiring collaboration between developers, local authorities, utilities and network operators. While this creates additional challenges, it also presents an opportunity to embed heat recovery into future developments from the outset rather than retrofitting solutions later.

Although waste heat recovery is often highlighted as a sustainability success story, delivering projects remains complex. The heat produced by data centres is typically low-grade and often requires heat pumps to raise temperatures before it can be distributed through a network. Building the necessary infrastructure requires significant upfront investment, while commercial agreements must align multiple stakeholders over the long term.

Timing is another challenge. A data centre may be operational years before surrounding developments requiring heat are completed, making coordination essential if opportunities are not to be missed. This is where heat zoning can make a real difference. By identifying future areas of heat demand and encouraging early collaboration, it creates a framework for connecting developments that may otherwise have been planned independently.

As data centres become increasingly prominent across the UK, there is growing public interest in the benefits they bring to local communities. Waste heat recovery offers an opportunity to demonstrate that these facilities can contribute far beyond digital connectivity. By supplying low-carbon heat to neighbouring developments, data centres can help reduce emissions, improve the viability of heat networks and support wider local sustainability targets.

There is still considerable untapped potential. Too often, data centres are planned in isolation rather than as part of wider energy infrastructure. Greater collaboration between developers, planners and energy providers could help unlock shared benefits for both operators and the communities around them.

Ultimately, heat network zoning has the potential to change the role data centres play in the UK's energy transition, but success will depend on a collective willingness to rethink established approaches and embrace long-term, joined-up planning. As digital infrastructure continues to expand, waste heat should no longer be viewed as an unavoidable consequence of growth, but as a valuable asset capable of supporting both economic development and decarbonisation goals.

By Bryony Evans, Intermediate Environmental Consultant, chapmanbdsp