What happened

As Hayley Mortimer and Adrian Goldberg reported for BBC News on 3 November 2026, BBC File on 4 Investigates found four planned "hyperscale" data centres that are already considering gas-fired power to meet their electricity needs while they wait for a connection to the national grid. It follows the Budget on 28 October, when the government's Data Centre Covenant said that exceptionally strategic data centres that cannot get a grid connection in time could be allowed to generate their own power on site, under a "tightly controlled framework", until the connection arrives. The Covenant does not say which fuel that generation would use. We covered it in our post on the Data Centre Covenant.

The four sites, as the BBC reported them from planning documents and developers' statements:

  • Quest Park, Bedfordshire (power load): 1,000 MW
  • Wapsey's Wood, Buckinghamshire (gas power station): 200 MW
  • Cardiff (temporary turbines, up to): 49.9 MW
  • Acre Slough, west of London (gas engines, up to): 49.5 MW

Together that is 1,299.4 MW, the BBC's 1.3 gigawatts. If run continuously at full capacity, the BBC calculates they could produce about 4.1 million tonnes of CO2 a year, which it says could be more than the cities of Manchester, Liverpool and Southampton combined. Some developers expect grid connections to take 10 years, and at Wapsey's Wood capacity is not expected until 2040. All four told the BBC they intend to connect to the grid when it can meet their needs. The BBC also reports Ofgem's figure that data centre developers are seeking grid connections totalling 72 GW, against peak demand across the whole country of 45 GW last year.

The government told the BBC that its priority is connecting data centres to the grid, and that any behind-the-meter generation would be tightly controlled, time-limited and allowed only for exceptionally strategic projects where capacity could not be secured any other way. Its draft National Policy Statement for Data Centres is open for comments until 8 January 2027.

Our sums: gas versus the grid

We checked the BBC's estimate against the government's own factor for grid electricity, using the same engine the app uses. These are upper limits: they assume every site runs at full output all year, which the BBC also assumed, and real data centres run below that.

  • 1,299.4 MW for 8,760 hours is 11.4 TWh of electricity a year.
  • The BBC's 4.1 million tonnes for that much electricity works out at about 0.36 kg CO2 per kWh.
  • The government's 2026 UK electricity factor is 0.13096 kg CO2e per kWh. The same 11.4 TWh from the grid would be about 1.5 million tonnes a year.
  • So running these sites on their own gas instead of the grid would add roughly 2.6 million tonnes of CO2 a year, about 2.8 times the grid's emissions for every kWh.
  • Wapsey's Wood alone, 200 MW running all year: about 631,060 tonnes at the BBC's implied rate, against 229,442 tonnes from the grid.

The grid figure is an average over the year. The grid is also getting cleaner each year as wind and solar grow, while a gas plant's emissions per kWh stay much the same for as long as it runs. That is why how long the temporary generation lasts matters as much as its size.

What it means for your business

Almost every business uses data centres, even if it never sees one. Email, accounts software, file storage, websites and AI tools all run in them. The electricity behind those services sits in your Scope 3, category 1, purchased goods and services. Take an illustrative business whose cloud and software services stand for 20,000 kWh of data centre electricity a year. At the grid factor that is 2,619 kg CO2e; if the same electricity came from on-site gas at the BBC's implied rate it would be about 7,204 kg.

Nothing changes in how you report today. The UK grid factor is a national average, and the four sites are proposals, not running plants. But as more of your work moves into AI tools, it is worth knowing where your providers' sites are and how they are powered, because their emissions become yours in Scope 3.

What to do now

  1. List your main digital providers. Cloud hosting, email, accounts and AI tools. Most publish a sustainability report or a customer emissions dashboard.
  2. Ask how their UK sites are powered. In particular whether any site uses on-site gas generation, and for how long. A location-based figure in kWh or kg CO2e for your account is the most useful answer.
  3. Keep spend-based estimates for the rest. Where a provider gives no figure, estimating from what you spend is a recognised method under the GHG Protocol and is better than leaving it out.
  4. Have your say if you have a stake. The draft National Policy Statement for Data Centres is open for comments until 8 January 2027.