The rapid expansion of cloud services and artificial intelligence workloads pushed UK data centre electricity consumption to an estimated 4.2 terawatt-hours in 2025, a figure that has more than doubled since 2018 and now accounts for roughly 1.4 per cent of national electricity demand, according to new research from the Energy Systems Catapult.
The growth trajectory has raised pressing questions about the sector’s long-term sustainability. With hyperscale facilities each drawing power equivalent to a small town, operators are under increasing scrutiny from regulators and corporate clients demanding credible decarbonisation plans.
“The industry has moved past the phase where buying renewable energy certificates was considered sufficient,” said Dr James Hargreaves, senior researcher at the Energy Systems Catapult. “Investors and tenants now want to see direct investment in on-site generation, waste heat recovery, and meaningful efficiency improvements at the chip level.”
Several operators have announced significant investments in the past quarter. A consortium led by two major colocation providers broke ground on a facility in Greater Manchester that will draw 60 per cent of its power from a dedicated solar and battery storage installation. Meanwhile, liquid cooling technology, which can reduce server energy consumption by up to 30 per cent compared to traditional air cooling, is moving from niche to mainstream adoption across the sector.
Artificial intelligence workloads are a particular concern, with GPU clusters for model training consuming several times more power per square metre than conventional server racks. A single large language model training run can generate carbon emissions equivalent to hundreds of transatlantic flights, though developers point out that inference costs are substantially lower once models are deployed.
The sector’s trade body, techUK, has published a roadmap targeting a 40 per cent reduction in average power usage effectiveness across member facilities by 2030. Achieving that goal would require retrofitting older sites, many of which were built when energy costs and carbon reporting were considerably less prominent in corporate decision-making.
Industry observers note that the economics are shifting in favour of efficiency investment. With industrial electricity prices in the UK remaining among the highest in Europe, the business case for cutting consumption has never been stronger. The challenge, Hargreaves added, is that planning and grid connection delays for renewable projects are stretching timelines beyond what many operators can accommodate without interim solutions.