Two UK datacentres will outpollute ExxonMobil. Their workaround is on-site gas

Two planned datacentres in southern England, Wapseys Wood in Buckinghamshire and Quest Park in Bedfordshire, will, at full load, release more carbon dioxide each year than ExxonMobil's entire UK operation emitted in 2023. The two sites, the buildings packed with servers that now power AI training, cloud services and everyday streaming, will together draw 1.3GW of electricity when fully operational, according to the planning documents cited in a Guardian analysis of the country's accelerating datacentre buildout. The carbon comparison comes from the non-profit group Foxglove, which has run the projected demand through the government's official carbon-intensity figures to arrive at 4.5m tonnes of CO2 per year. ExxonMobil's UK emissions in 2023, by contrast, were 3.9m tonnes, according to Ember's annual review of the largest UK emitters.

The two sites are not an outlier. The UK grid-connection queue now holds 315 datacentre projects representing 73GW of demand, almost double the country's peak winter electricity use. Neither Wapseys Wood nor Quest Park can wait for new transmission lines, and both have applied to build on-site gas-fired power stations, the behind-the-meter (bypassing the public grid) workaround for a grid that cannot move fast enough to power a compute buildout measured in tens of gigawatts.

The government has called Foxglove's figures "misleading" because they assume 100% utilisation from day one, an assumption a spokesperson said was "not accurate." Tom Hegarty of Foxglove defends the methodology: 100% utilisation is standard industry practice for top-line emissions projections. Kierra Box of Friends of the Earth adds that the sites are designed to ramp to full load, so the projections are "valid."

Carbon Brief has separately warned that real-world emissions from UK datacentres could be hundreds of times higher than headline estimates if measured rather than projected. A wider decarbonisation analysis is sharper still: a joint report from Foxglove and Global Action Plan last September called Big Tech datacentres "a threat to UK decarbonisation."

The mechanism that decides whether any of this is permitted sits at the level of the seventh carbon budget, the UK's legally binding cap on emissions through 2037. A government spokesperson has said the department's own modelling shows "multiple pathways" to fit the rapid datacentre rollout within that budget, though with a "high level of uncertainty." That uncertainty is the political space the two planning applications now sit inside.

Caroline Lucas, the former leader of the Green Party of England and Wales, called the projected emissions "absolutely horrifying" and said the figures should ring alarm bells across government. The live policy thread is the Commons environmental audit committee, which is conducting a parliamentary inquiry into the environmental impact of datacentres. According to the Guardian, its chair, the Labour MP Toby Perkins, has described Foxglove's analysis as a serious challenge to the government's planning assumptions.

The two planning applications, for Wapseys Wood and Quest Park, will be decided against the seventh carbon budget, not against the datacentre queue. If the on-site gas turbines are approved, the workaround becomes a precedent for the next 313 applicants behind them.