What are data centres and how sustainable are they?

DOI: https://doi.org/10.58248/PN762

Data centres are buildings that contain the information technology equipment that most of the digital world relies on. They underpin most aspects of modern life, including economic activity, public service delivery, and how we interact with one another.

They are commonly defined as structures used to house, connect, and operate computer systems; for example, servers, for data storage, processing or distribution. They are crucial for cloud computing and artificial intelligence (AI).

Industry body techUK estimated in November 2024 that UK data centres contribute £4.7 billion in annual gross value added (GVA) to the UK economy, “…with the potential to contribute an additional £44 billion to the UK economy by 2035.”

In September 2024, the UK Government designated data centres as critical national infrastructure. In January 2025 they announced five ‘AI Growth Zones’ around the UK, and reported £28.2 billion of planned investment, and 15,000 expected jobs.

This POSTnote discusses what data centres are, how many there are in the UK, where they are, and addresses generic and local concerns. It also discusses the sustainability of their components and resource usage. It does not discuss supercomputing capacity in the UK. See the 2025 House of Commons Library briefing on data centres for details on resilience and planning law.

How many data centres are there, and what does ‘hyperscale’ mean?

The UK has around 450 large data centres, with London holding more capacity than the rest of Great Britain combined. They are typically defined in terms of power usage, with the Cyber Security and Resilience Bill 2025, defining enterprise data centres as having an ‘IT load’ of more than 10 MW. The IT load is the “…maximum electrical power available for the operation of relevant IT equipment”.

‘Hyperscale’ data centres refers to large-scale, ‘distributed computing’ centres that support high volume data processing, computing, and storage services. Distributed computing uses multiple computers, servers and networks to perform varying computing tasks.

Hyperscale refers to both the size of the data centre and its ability to ‘scale up’ capacity in response to demand. Organisations that build these data centres are known as ‘hyperscalers’, with some of the largest being, for example, Microsoft Azure, Google Cloud, and Meta.

Demand

Demand for data centre services is expected to grow, driven by cloud computing, artificial intelligence, and digitalisation, although the scale and timing of this growth are uncertain.

How do data centres use energy and water?

In July 2025, the UK National Energy Systems Operator (NESO) estimated that data centres used about 2% of all UK electricity. Most data centre energy powers the server computing directly, with around a third used for cooling.

Servers used for AI typically draw more power and fluctuate more than those engaged in data storage or other general computing.

Water can be used directly, for instance in some cooling systems, and indirectly, for example, in electricity generation or semiconductor manufacturing. The International Energy Agency estimated global data‑centre water consumption at around 560 billion litres in 2025, with about two‑thirds from electricity generation.

How sustainable are data centre components?

Components such as servers, network equipment and batteries have the shortest lifespans of around three to eight years, and contribute the most to data centre ‘e-waste’. Circular‑economy strategies have been recommended by environmental experts, and include refurbishing, remanufacturing and recycling components.

Such strategies can reduce environmental impact, but some researchers say too much UK e‑waste is exported to countries with weaker regulation, which raises environmental concerns.

What is the ‘operational sustainability’ of data centres?

Operational sustainability is the set of strategies that ensure daily operations are environmentally responsible, economically reasonable, and socially fair. It is influenced by adequate and non-excessive supply of services, sustainable building design, and integration with local communities.

For instance, some schemes reuse low‑temperature waste heat in ‘heat networks,’ but they are not widespread in the UK. Trade body techUK said that challenges include data centre location in relation to homes, planning times, and that heat networks produce more heat in the summer when it is not needed for heating.

Concerns about data centres include pollution from ‘forever chemicals’ or PFAS that are used in some cooling fluids and electronics, noise from cooling and generators, and local air pollution from diesel backup systems.

Some experts argue that inefficient data management and the accumulation of low-value or unused data, or ‘data waste’ can increase demand for storage and computing infrastructure, contributing to higher energy use, costs, and environmental impacts.

Public attitudes to data centres are mixed, with support varying depending on local benefits, such as employment, and impacts, such as water usage. One study by industry body techUK found that national support for expanding data centre infrastructure is 52%, but drops to 44% locally.

How are data centres regulated?

UK regulation of data centres is developing, but some current planning and environmental legislation is in place, for instance, the National Planning Policy Framework now explicitly supports data centre growth.

Also, planning rules require biodiversity net gains for proposed data centre sites, and may seek water and energy impact assessments.

The Cyber Security and Resilience (Network and Information Systems) Bill 2025, which had its first reading in November 2025, proposes treating data centres as essential services. It aims to impose risk‑management duties on data centre organisations, such as ensuring against cyber attacks.
Further information about the Bill can be found in House of Commons Library briefing paper Cyber Security and Resilience (Network and Information Systems) Bill 2024–26.

New international initiatives are emerging, such as the EU Energy Efficiency Directive, which focuses on data centre organisations being consistent in reporting impacts and efficiency.

Acknowledgements

This briefing was produced in consultation with experts and stakeholders, who are listed at the end of the briefing. The briefing was co-funded by the Engineering and Physical Science Research Council. POST would like to thank everyone who contributed their expertise to this briefing.