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UK grid connection waits for data centres: what's decided, what's proposed

The short answer

There's no single national wait. Government has described waits of up to 15 years (March 2026), and SSEN advised some West London demand of delays up to 14 years (2023). Ofgem's reforms since 2023 cut and reordered the queue, and in July 2026 it proposed a commitment fee of £237,500 to £712,500 per MW for data centres of 40 MW and above. That fee was still awaiting a decision in October 2026.

Hexi Industries engineering. Updated 11 October 2026. Every figure links to its source.

Grid connection is the single biggest reason AI capacity in Britain arrives late. This page tracks what has actually been decided, what is only proposed, and what has been reported, with the date and source for each. We update it as decisions land.

Queue figures below measure different things: some are mostly generation, some transmission-connected demand only, some contracted offers. Don't add them up or compare them as one series.

Timeline

  1. March 2023

    Reported

    West London: waits of up to 14 years

    SSEN reported transmission constraints at six West London grid supply points, with new demand above 250 kVA advised of delays of up to fourteen years.[1]

  2. 13 Nov 2023

    Decided

    Queue milestones for transmission contracts

    Ofgem approved CMP376 (WACM7): progression milestones and termination rights for transmission connection contracts, from 27 November 2023.[2]

  3. 22 Nov 2023

    Announced

    Connections Action Plan

    Government and Ofgem set an ambition to cut the average gap between requested and offered transmission connection dates from 5 years to 6 months, and considered asking customers to return unused capacity.[3]

  4. 25 Mar 2024

    Reported

    701 GW in the queue

    Ofgem reported 701 GW waiting to connect, mostly generation and storage, with 17 GW offered earlier dates.[4]

  5. 13 Jan 2025

    Announced

    First AI Growth Zone at Culham

    Government announced a first AI Growth Zone at Culham, starting with 100 MW and planned to grow to 500 MW, subject to a partnership.[5]

  6. 10 Mar 2025

    Reported

    Government cites waits of up to 10 years

    Announcing the Planning and Infrastructure Bill, government described waits of up to 10 years for some projects to connect.[6]

  7. 15 Apr 2025

    Decided

    Ofgem approves connections reform (TMO4+)

    A package prioritising projects that are 'ready' and 'needed', taking effect on 10 June 2025.[7]

  8. 8 Jul 2025

    Reported

    Whole-queue evidence window opens at 738 GW

    NESO asked existing projects for evidence of readiness, with the queue standing at 738 GW.[8]

  9. 13 Nov 2025

    Proposed

    AI Growth Zones: priority mechanisms

    Government proposed reallocating released capacity and reserving future capacity for strategic demand, forecasting time-to-power cut by up to 5 years.[9]

  10. 19 Nov 2025

    Decided

    SSEN extends ramped connections

    Ramped demand connections of 1 to 15 MVA, growing by up to 5 MVA a year, across SSEN's central southern England area, subject to assessment.[10]

  11. 8 Dec 2025

    Decided

    Reformed pipeline confirmed

    NESO confirmed 283 GW of generation and storage and 99 GW of transmission-connected demand in the prioritised pipeline; more than 300 GW did not progress at that stage.[11]

  12. 11 Mar 2026

    Reported

    Waits of up to 15 years

    Government said demand applications to the transmission network grew 460% in the six months to June 2025, contributing to waits of up to 15 years, and announced action on speculative requests.[12]

  13. 12 Mar 2026

    Consultation

    Strategic demand consultation

    Proposals to reallocate, reserve and prioritise capacity for government-identified strategic demand, including possible regional alignment for data centres. Closed 15 April 2026; no final response found by October.[13]

  14. 16 Jun 2026

    Proposed

    Demand reform: Connect Accelerate and Connect Operate

    Ofgem explored self-build, phased and non-firm connections, flexibility and possible backstop controls, with consultations expected in autumn 2026.[14]

  15. 29 Jul 2026

    Reported

    Data centres drive a jump in contracted demand

    Ofgem reported contracted demand offers rising from 41 GW to 125 GW between November 2024 and June 2025, and around 7.8 GW of projects accelerated by an average of six years.[15]

  16. 29 Jul 2026

    Proposed

    A commitment fee for large data centres

    Ofgem proposed security of £237,500 to £712,500 per MW, for data centres of 40 MW and above, returned if a project progresses, plus new milestones for projects from 10 MW of IT load. Closed 17 September 2026, awaiting decision.[16]

  17. 1 Oct 2026

    Reported

    Most 2030 offers issued, delivery still ahead

    NESO said more than 75% of the offers needed for the 2030 energy system had been issued, and that issuing offers is different from delivering projects.[17]

  18. 7 Oct 2026

    Consultation

    Self-build for transmission connections

    Ofgem consulted on letting demand, generation and storage customers build their own sole-use transmission assets. Closes 13 November 2026.[18]

What it means for a smaller AI deployment

Most of these rules are aimed at large, new connections. Ofgem's proposed fee would apply from 40 MW, and its proposed milestones from 10 MW of IT load[16]. A pod of one to two megawatts on a site's existing agreed capacity doesn't join a new connection queue at all, though the network operator should still be told about significant new load.

That's the gap Hexi pods are built for: they use the spare import a site already has, about 930 kVA to 1.7 MVA depending on rack count. Our guide to finding spare capacity on a site explains how to check.

Questions people ask

How long does a new grid connection take in the UK?
There's no single national figure. Government has described waits of up to 15 years (March 2026), and SSEN advised some West London demand of delays up to 14 years (2023). Times depend on size, location and whether the transmission network is affected.
Why do grid connections take so long?
Queues filled with far more projects than will be built: Ofgem reported 701 GW waiting in March 2024, and contracted demand offers rose from 41 GW to 125 GW in under a year, driven largely by data centres. Reforms since 2023 aim to prioritise projects that are ready and needed.
Is there a fee for data centres to join the queue?
Proposed, not decided. In July 2026 Ofgem proposed a refundable commitment fee of £237,500 to £712,500 per MW for data centres of 40 MW and above. The consultation closed in September 2026 and was awaiting a decision in October.
Do AI Growth Zones get faster connections?
Government has proposed mechanisms to reserve and reallocate capacity for strategic demand, forecasting time to power cut by up to five years. The detailed rule changes were still to come as of October 2026.
Can I avoid the queue altogether?
For a load within a site's existing agreed capacity, there's no new connection to queue for, though the network operator should be told about significant new load. That's the route a Hexi pod takes: about 1.5 MVA of spare import for seven GPU racks.

Sources

  1. 1. West London interim ramping solution pilot guide. SSEN, March 2023.
  2. 2. CMP376 decision. Ofgem, 13 November 2023.
  3. 3. Connections Action Plan. DESNZ and Ofgem, 22 November 2023.
  4. 4. Preparing for faster, more efficient electricity connections. Ofgem, 25 March 2024.
  5. 5. AI Opportunities Action Plan: government response. DSIT, 13 January 2025.
  6. 6. Planning revolution to fuel growth. GOV.UK, 10 March 2025.
  7. 7. Decision on the connections reform package. Ofgem, 15 April 2025.
  8. 8. Evidence window opens. NESO, 8 July 2025.
  9. 9. Delivering AI Growth Zones. DSIT, 13 November 2025.
  10. 10. Ramped connections in central southern England. SSEN, 19 November 2025.
  11. 11. NESO implements grid connection reforms. NESO, 8 December 2025.
  12. 12. Government to tackle speculative demand grid connection requests. GOV.UK, 11 March 2026.
  13. 13. Accelerating electricity network connections for strategic demand. DESNZ, 12 March 2026.
  14. 14. Demand connections reform update. Ofgem, 16 June 2026.
  15. 15. Ofgem acts to free grid capacity. Ofgem, 29 July 2026.
  16. 16. Proposed data centre connection reforms. Ofgem, 29 July 2026.
  17. 17. What industry needs next from connections reform. NESO, 1 October 2026.
  18. 18. Enabling greater self-build of transmission connections. Ofgem, 7 October 2026.

This guide is general information, not legal, engineering or financial advice. Hexi engine figures are estimates until a firm offer. Spotted an error? Email louis@hexi.industries and we'll correct it.

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