US rollout could emit 345m metric tonnes of CO2e a year
BloombergNEF research published on Wednesday, Nov. 11, finds that datacentre projects planned across the US, UK and mainland Europe include proposals for on-site gas-fired plants with a combined capacity of 181GW — almost four times the total peak electricity demand of Great Britain. The proposals stem from delays in connecting the facilities to national grids.
The proposed capacity is concentrated in the US, where 90% of the planned on-site gas-fired power stations are located. If the planned rollout happens, the US plants would emit about 345m metric tonnes of carbon dioxide equivalent a year, according to the research — roughly the annual greenhouse gas emissions of about 72.8m fossil fuel cars.
Mark Daly, the head of datacentres and emerging tech at BloombergNEF, said the economics of AI have made speed to power one of the most important constraints on datacentre developers. “The extraordinary economics around AI are making speed to power one of the most important priorities for defining constraints on datacentre developers,” Daly said. “The climate outcome will depend not only on how much electricity these facilities use, but on how quickly grids can connect them and whether power systems add cleaner generation alongside that demand.”
Daly said developers describe their gas-fired supplies as temporary arrangements while they wait for grid connections. Once the plants are operating, he said, the economics could encourage operators to keep generating power, creating a longer-term risk of fossil-fuel lock-in.
AI datacentres draw heavy electricity to run servers, cool equipment and operate facility systems. The report projected that by 2035 the electricity demand of AI datacentres would almost quadruple to 2,354 terawatt-hours, equivalent to 7% of global electricity demand.
In the UK, planned datacentres made more than 100 inquiries in 2024-5 to connect to gas as a result of delays securing access to the electricity grid, according to Future Energy Networks, the representative body for the UK gas networks. Wapseys Wood in Buckinghamshire and Quest Park in Bedfordshire are each seeking to build their own on-site gas-fired power stations after long waits for grid connections.
Both projects are among the first to be fast-tracked through the government’s nationally significant infrastructure project regime, which allows developers to rapidly deliver major infrastructure and bypass locally elected planning authorities.
John Healey, the chancellor, gave the green light for datacentres to build and run temporary on-site fossil fuel power stations while they wait for connections to the grid, as part of a so-called datacentre covenant. The Guardian reported that the use of fossil fuel generation on site is likely to be repeated by many more UK sites.
BloombergNEF said connecting new datacentres to the grid is the more sustainable option, and that faster grid connections are crucial both to limiting emissions impacts and to avoiding fossil-fuel lock-in.
Oliver Hayes, the head of policy and campaigns at Global Action Plan, disputed the claim that the plants will be temporary. “Private gas power stations for datacentres should be a red line for any government serious about climate action, so it’s shocking to see the chancellor give them his explicit backing,” Hayes said. “No one seriously believes these gas power stations will be temporary – once they’re built, they’ll lock in high emissions for years.”
The developments arrive as global leaders gather in Turkey for the 31st UN climate summit, Cop31, where increasing electrification — ideally from clean sources — is a central part of the discussions. A number of key European leaders, including from France and Germany, will not attend Cop31 and are heading instead to Dublin, where EU leaders are to hold their first dedicated AI summit on Friday.
How much electricity the facilities use, how quickly grids can connect them, and whether power systems add cleaner generation alongside the new demand will all shape the climate outcome, Daly said.