Does the rapid growth of data centres in the UK and around the world represent a threat to carbon emission targets? In column in the June issue of Energy in Buildings and Industry, Andrew Warren considers their predicted increase in energy demand and potential impact on the environment.
What’s powering data centre growth?
The UK is experiencing a remarkable growth in its digital infrastructure. Data centres – facilities that house the servers and equipment powering everything from cloud storage to artificial intelligence – are expanding at an unprecedented rate. And seriously fuelling up energy demand.
As recently as 2023, according to the National Energy System Operator (NESO), data centres consumed 5.0 TWh of electricity. This was just 2% of total UK electricity demand. Subsequently, there are now a further 50+ data centres set to be added this decade. It estimates that total demand from data centres could reach 26.2 TWh by then – approaching 9% of total electricity demand.
Data centres (DCs) are ultra energy-intensive operations, consuming between 10 and 50 times more electricity per square metre than a typical commercial building. That difference depends a lot on whether Chinese or American AI inputs are used. The average U.S. AI data centre equates to the energy usage of around 100,000 households, while the Chinese DeepSeek tool is proving to be so much more energy efficient.
In 2023 DCs were responsible for 7% of UK commercial sector energy consumption. By 2030, that figure could exceed 30%.
National renewal
Government policy is to “turbocharge” and “unleash” AI, to deliver “a decade of national renewal”, with Prime Minister Sir Keir Starmer “throwing the full weight of Whitehall behind this industry”. But despite many right-wing criticisms, it also remains his policy to ensure that the grid will be almost entirely carbon-free by then.
Hence, the bland assumption from the science department (DSIT) that any increased carbon emissions from data centres will be minimal. Apparently, a decade on, all this anticipated growth in energy consumption will be adding just 0.05% to the UK’s projected total emissions.
This confidence is based upon the presumption that each DC will be using only non-fossil fuel electricity for all its activities. But a big concern remains: are the DCs now under development prepared to wait for this decarbonisation to occur?
Added pressure
The union UNISON has analysed the developers’ own figures, revealing that between them just 10 of these 50 anticipated DCs are set to cause additional annual emissions of 2.7m tonnes. As the Greater London Assembly’s 2025 report ‘Gridlocked’ revealed, the rise of DCs in West London alone has put extra pressure on the electricity network, competing with new housing and EVs for limited new supply.
At least 100 GW of demand for electricity grid connections are currently being sought by these putative DCs. Such is the waiting list to acquire connections that the relevant director of the energy regulator, Ofgem, Stuart Okin, admits “clearly, that is not all going to be able to connect to the grid”. He concedes that “if a project isn’t going to get a connection, it is going to have to come up with an alternative method”.
That alternative method is most likely to be gas-fired. Future Energy Networks represents UK gas suppliers. According to its head of research, Silvia Simon, they have received “more than 100 requests” for gas connections from DC operators – all adding up to over 15TWh a year. These requests are “not just for resilience, but for primary supply”. And not just as a temporary fix.
Gas guzzlers
Globally, orders for new gas-power plants increased to 130 gigawatts in 2025 – easily the highest this century, according to the International Energy Agency. Most of this has happened in the USA, and much of that is for data centres run on off-grid gas generators. Just 11 US data centres built to serve META, Open AI, Microsoft and xAI emit more carbon than the whole of Morocco.
According to the IEA, such investments are “limiting the availability of turbines for near-term deployment elsewhere in the world”.
Meanwhile, legal action against the UK government and data centre developer Greystoke has established the precedent that all data centre developers’ claims on measures to protect the environment must be “concrete and enforceable” (see EiBI Feb 2026 page 7).
Greystoke was seeking to build a 90MW data centre at Woodlands in Buckinghamshire. The local council initially rejected the proposal, but the government ‘called in’ the plans and overturned the decision. Environmentalists argued the government’s decision was unlawful, because it too was failing to properly consider the energy use and environmental impact of the planned facility. This January, the government admitted it had made a “serious logical error” in giving the go-ahead, and conceded the case.
Climate targets
Even so, NESO appreciates that the imminent gas buildout is seriously complicating Britain’s climate goals. Its strategic planning director Julian Leslie acknowledges that, even if the non-fossil fuel electricity target is achieved, “obviously if we’ve got data centres not connected to electricity, but powered by unabated gas, then it does raise an interesting question about what that means for the Clean Power 2030 target”.
Meanwhile, the United Nations is calling for a moratorium on the development of data centres. This is based on concerns about “their water and energy consumption and the risks they pose to climate change, the sustainability of aquatic ecosystems, the human rights of impoverished populations and the survival of vulnerable productive sectors”.
About the author: Andrew Warren chairs the British Energy Efficiency Federation
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Energy in Demand - Sustainable Energy - Rod Janssen 