The UK’s data centre market is booming, driven by rising demand for data and the government’s focus on AI as a key growth area for the economy.
With 487 data centres already operational, the UK ranks as the third-largest market globally, trailing only the US and Germany. Segro’s Slough Trading Estate is the largest concentration of data centres in Europe.
While the growth of this sector provides many opportunities, it also forces us to face the question: how can the UK balance its ambitions for digital transformation with its net zero 2050 goals?
Data centres are among the most energy-intensive building types, accounting for 2% to 3% of global carbon emissions. Cooling systems alone use around 45% of a data centre’s energy. A further risk factor is the growth of hyperscale data centres.
The International Energy Agency (IEA) notes that while an average data centre might have a demand of 5 to 10 megawatts (MW) a hyperscale data centre will draw 100MW or more. As the IEA states, that is: “Equivalent to the electricity demand from around 350,000 to 400,000 electric cars.”
The government’s target sees data centres meeting 18% of UK heating needs by 2050
Shahid Rahman EMEA Data Centre Strategic Account Lead
Sustainable growth
So, as the UK expands its data centre sector, energy efficiency and sustainability must be priorities.
A major area of potential is waste heat recovery from data centre cooling systems for reuse in heat networks. It is an approach that can shift data centres from being energy consumers to energy contributors, making them a potentially key part of the UK’s low-carbon heat future.
This is an important re-think of our approach to data centre design. Although technologies like highly efficient liquid cooling are developing, they are not currently widely used. However, looking at data centres as potential heat sources puts them in a completely different light.
Heat networks are currently a small part of the UK energy system, producing only 2% of our heat. However, there is enormous potential for growth.
Government backing
The government’s Heat and Buildings Strategy highlights their potential role in decarbonising the UK’s heating systems, with a target of meeting 18% of UK heating needs by 2050.
Data centres, with their consistent heat output of 30°C to 35°C, are well-suited to support this transition.
Government support for heat networks is not just theoretical. The Energy Act 2023 introduced heat network zoning, requiring certain buildings to connect to local heat networks.
Additionally, the government has allocated £350 million to expand low-carbon heat networks.
These policies, alongside government’s AI goals, point to data centres as a key source of low-carbon heat for district heating and other applications.
Already working
Heat pumps play a critical role in these waste heat recovery systems. They can elevate the temperature of data centre output heat to levels suitable for domestic or commercial use, such as 70°C to 80°C.
It is an approach that is already being used successfully.
For example, Tallaght in the Republic of Ireland is the country’s first low carbon district heating network. The system is based around two FOCS2-W chiller and reversible heat pumps by Mitsubishi Electric, which use lower GWP refrigerant (HFO R1234ze).
During normal operation, the heating demand from the network is fully covered by the data centre’s ejected heat, while peak requests in winter are satisfied by dedicated heat pumps and a heat pump module, supplied by Mitsubishi Electric partner Nohewa.
This is a growing network, with more homes and public buildings due to be added in the future. (You can find more examples in our publication Data centres: Heat reuse for a low carbon future).
Shifting perspectives
Implementing heat recovery systems at any scale requires careful planning and collaboration. Factors such as proximity to heat demand, compatibility with heat networks, and long-term sustainability goals must be considered during the design and construction of new facilities.
The UK government is determined to harness the power of AI for businesses and government operations. It has established an AI Energy Council to explore sustainable energy sources such as small nuclear to balance this drive with its sustainable ambitions. But heat reuse is the step that could make the biggest difference to how data centres are perceived.
This is not just a case of public perception of data centre growth. It’s also about attracting developers and clients who are increasingly concerned that the data centres they build and use are seen as enhancing the environment, not damaging it.
The integration of heat recovery systems into data centres is more than a technical upgrade, it’s a shift in perspective. By transforming waste heat into a resource, data centres can bridge the gap between the UK’s high-tech aspirations and its low-carbon commitments.
Shahid Rahman is EMEA Data Centre Strategic Account Lead
