UK Government Departments Clash Over AI Datacentre Energy Demands

The Government's Energy Calculations Clash

The UK government is facing internal divisions over the energy demands of AI datacentres, with two key departments offering vastly different projections. While the Department of Science, Innovation and Technology (DSIT) forecasts that AI datacentres will consume 6GW of electricity by 2030, the Department of Energy Security and Net Zero (DESNZ) projects usage of less than a tenth of that amount. This discrepancy raises questions about how the UK can simultaneously pursue its ambition to become an AI superpower while meeting decarbonization targets.

Conflicting Projections from Key Departments

The DSIT's "UK compute roadmap," published in 2025, sets out a "bold, long-term plan to transform our national compute ecosystem" by building AI datacentres. The document explicitly states: "We forecast that the UK will need at least 6GW of AI-capable datacentre capacity by 2030." This ambitious plan involves creating multiple AI growth zones across the country, each requiring at least 500MW of electricity.

In contrast, DESNZ, which is responsible for the UK's carbon budget and climate targets, has incorporated AI datacentres into broader forecasts for the energy use of Britain's "commercial services" sector. These projections suggest the entire sector's energy use will grow by just 528MW between 2025 and 2030 – equivalent to adding the consumption of 1.7m homes by the end of the decade.

The DESNZ has stated it does not hold separate projections for datacentre growth, despite the government's commitment to building significant AI infrastructure.

The Scale of the Discrepancy

The difference between the departments' projections is staggering. DSIT's estimate of 6GW for AI datacentres alone is more than ten times higher than DESNZ's projection for the entire commercial services sector's growth. This means that if DSIT's projections are accurate, the energy demands of AI datacentres would far outpace the government's current plans for grid expansion and decarbonization.

Each proposed AI growth zone would require at least 500MW of electricity – an amount only slightly less than DESNZ's forecast for the increase in energy usage of the entire commercial services sector. This suggests that even a handful of these zones would strain the government's energy planning.

Revised Emissions Figures and Controversy

The controversy surrounding these projections deepened when DSIT revised its figures for the carbon emissions of AI datacentres. Originally, DSIT's projections for the carbon emissions of additional AI computing capacity were between 0.025m and 0.142m tonnes of carbon equivalent (MtCO₂) – below 0.05% of Britain's projected emissions.

After questions were raised about the plausibility of these figures, the document containing them was removed from the government website. Then, after inquiries from The Guardian, DSIT updated its numbers significantly. In a statement posted online, the department acknowledged: "The UK's cumulative 10-year greenhouse gas emissions from AI compute could range from 34 to 123 MtCO₂ – this is around 0.9-3.4% of the UK's projected total emissions over the 10-year period."

This represents more than a hundredfold increase in the estimated emissions, raising serious questions about the initial calculations and the transparency of the government's planning process.

Critics Question Government Competence and Corporate Influence

The conflicting projections have drawn sharp criticism from experts and observers. Tim Squirrell, the head of strategy for the NGO Foxglove, commented: "The government's cluelessness over the environmental impact of datacentres would be laughable, if it weren't so alarming."

Cecilia Rikap, a researcher at University College London, offered two possible interpretations of the "misalignment": either DESNZ and DSIT are incompetent, or there's some kind of "magical thinking about AI and big tech." She added: "Either way, the episode uncovers how these corporations control not only the AI value chain, but also the UK government."

Foxglove filed an environmental impact assessment request with DESNZ in January, asking how the department had incorporated AI datacentres into its projections for Britain's emissions. The response, which referred to broader forecasts for the commercial services sector, did not address the specific concerns raised.

Future of UK AI Strategy and Climate Goals

The UK government appears to be attempting to balance competing priorities: becoming a leader in artificial intelligence while meeting international climate commitments. Carbon budget 7, which will outline the UK's climate plans for the coming years, is set to be released this summer and may provide more clarity on how these objectives will be reconciled.

A spokesperson for DESNZ noted that "datacentre emissions are factored into our modeling, including for carbon budget 7," and mentioned that "The AI Energy Council is exploring opportunities to attract investment and support the development of clean power for datacentres."

However, the significant discrepancy between government departments suggests that the UK's strategy for becoming an AI superpower may be developed without adequate consideration of its environmental implications. As the government moves forward with its AI ambitions, the tension between technological advancement and climate responsibility will likely remain a central challenge.