UK data centres turn to gas as grid queue grows
Key Points
- More than 100 new UK data centres plan to burn gas on site rather than connect to the grid.
- NESO told HotMinute it expects many to include on-site generation, but would not give pipeline, gas or wait-time figures.
- Ofgem puts indicative data centre demand in the transmission queue at around 50GW, reflecting developer intent, not confirmed projects.
- NESO says data centres could add up to 71 TWh of electricity demand in Britain by 2050.
- NESO's Clean Power 2030 advice assumed unabated gas would supply less than 5% of electricity.
More than 100 new UK data centres plan to generate their own electricity by burning gas rather than connect to the national grid.
British officials have described the move as a consequence of grid connection waits that can run to several years.
NESO, the operator that plans Britain’s network and runs connections for the largest projects, told HotMinute it expects many data centres to include on-site generation for resilience.
Ofgem estimates the connection queue holds around 50GW of data centre demand, a figure NESO says reflects developer intent rather than confirmed or deliverable projects.
Why operators turn to gas
Data centre developers in the UK can wait as long as 10 years, Oxford Economics says, with some industry estimates running to 12 to 15 years.
National Gas, which runs Britain’s gas pipeline network, has confirmed that five large data centre projects in the south of England asked about gas connections, The Register reported, after the Financial Times first revealed the enquiries.
An on-site gas plant can produce power before a grid connection is available, and more than 100 new sites plan to use one, some of them permanently.
What NESO told HotMinute
HotMinute asked NESO for the number of data centre connection requests in the pipeline, how many propose on-site gas, the current average wait, and a regional breakdown.
NESO declined to provide those figures and said it has not released a number for data centre demand, pointing instead to Ofgem’s indicative estimate of around 50GW on the transmission network, which it says reflects developer intent rather than confirmed or deliverable projects. A
NESO spokesperson said the operator expects many data centres to include on-site generation for resilience, and that where a site sits can change how much new network it needs, in some cases reducing pressure on the grid.
NESO said data centres could add up to 71 TWh of electricity demand in Britain by 2050, and that flexible sites could shift demand away from peak times while some could pass waste heat to local heat networks.
The operator runs connections only for large projects on the high voltage transmission network and does not handle the lower voltage distribution networks where most existing data centres sit. NESO said it sits on the AI Energy Council alongside government and industry.
The numbers at a glance:
| Figure | Number | Notes |
|---|---|---|
| Ofgem estimate of data centre demand in the transmission queue | Around 50GW | Indicative only; reflects developer intent, not confirmed or deliverable projects, NESO says |
| Potential added electricity demand by 2050 | Up to 71 TWh | NESO figure shared with HotMinute |
| New UK data centres planning to burn gas on site | More than 100 | Some permanently, per reporting |
| Typical wait for a grid connection | Up to 10 years | Industry estimates; some reports cite 12 to 15 years |
| GB demand connection queue, mid 2025 | Around 125GW | Data centres a large share of the recent increase, per analysis of Ofgem figures |
The grid queue and Clean Power 2030
Ofgem’s reforms removed projects from a generation queue that had grown past 700GW. The demand side has grown separately, reaching around 125GW by mid 2025, with data centres a large part of the increase, according to analysis of Ofgem’s figures.
NESO’s Clean Power 2030 advice assumed unabated gas would supply less than 5% of electricity, and the data centre gas plants would operate outside that plan. NESO has recommended a once in a lifetime expansion of the grid and clean generation, the cost of which is recovered through consumer energy bills.
NESO opens its next connections applications window in the second half of 2026 and is reforming how it handles demand from data centres and other large users, work it has set out in its connections reform documents.
