The UK government’s ambition of reaching net zero carbon emissions by 2050 could be undermined by its own new arrangement for AI data centres, according to BBC research.
In the Budget speech, Chancellor John Healey said data centres would be allowed to build onsite power generation while they wait for a grid connection. BBC File on 4 Investigates has found that four planned “hyperscale” data centres — three of them in the south of England — are already considering gas-fired power to meet their electricity needs.
The number
If those four ran continuously at full capacity, the BBC calculates they would require 1.3 gigawatts and could produce an estimated 4.1 million tonnes of carbon emissions a year. That is more than the cities of Manchester, Liverpool and Southampton combined.
Labour MP Toby Perkins, who chairs the Environmental Audit Select Committee, said a substantial increase in natural gas use “can’t be the future”. He added: “Government absolutely shouldn’t be in the business of just saying anyone who wants to bring it here, can do whatever you like to power it, because that is not acceptable.”
Why they are not simply using the grid
Because they cannot get onto it. Ofgem, the energy regulator, says data centre developers are seeking connections totalling 72 gigawatts. For scale, peak electricity demand across the entire United Kingdom last year was 45 gigawatts.
Some developers have been told they could wait up to 10 years for the system to be upgraded enough to connect them. Nathan MacWhinnie, head of market intelligence and oversight at Ofgem, put it plainly: “In a lot of places, the grid is at capacity. I think sometimes it’s easy to forget the scale of the demand of these connections. These projects are sometimes the size of cities.”
That queue is what the onsite generation rule is meant to solve. It also explains why gas is attractive: a developer who must wait a decade for a connection is not going to wait a decade to open.
The two sites with numbers attached
The scale varies. At Acre Slough, west of London, developers say they could use gas engines with a generating capacity of up to 49.5 megawatts while waiting for a National Grid connection they expect could take at least ten years.
At Wapsey’s Wood, next to the M40 in Buckinghamshire, a proposed 200-megawatt gas power station could operate until sufficient grid capacity becomes available — currently not expected until 2040.
“It would be a disaster for us environmentally,” said Buckinghamshire independent councillor Ed Gemmell, who also leads the Climate Party.
What the government says
The government said data centres were “essential to Britain’s economy” and pointed to its new Data Centre Covenant, which it says sets clear expectations that developers pay a fair share of the costs they impose on the energy system and deliver benefits for local communities.
Announced in the Budget, the covenant requires operators to invest locally, create jobs and protect water supplies in return for priority grid connections. The same speech permitted onsite generation where connections are unavailable — which is the clause the four sites are relying on.
What gas on site actually means locally
Oliver Hayes, head of campaigns at the environmental charity Global Action Plan, described the consequence for people living nearby: “If we’re powering by gas that means local communities are going to have huge gas turbines on their doorstep, and they are going to be generating a huge amount of local air pollution and a huge amount of noise and they will be using a huge amount of water from the local water supply.”
Data centres have been part of the British landscape for over two decades, running streaming, banking and public services. The new generation is a different proposition: built for AI workloads, far larger, and arriving while the grid is already struggling.
