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The reformed pipeline and the distribution build window.
The pre-reform UK connections queue stood at over 738 GW — roughly three to four times the 200–225 GW the country can physically build by 2030. Allocation, not generation, was the bottleneck.
NESO's Connections Reform Results (8 December 2025) reshaped that queue into 283 GW of Gate 2 offers — the live pipeline, split 132 GW pre-2030 and 151 GW for 2030–2035 — plus 216 GW of Gate 1 indicative offers with a route but no contracted date.
The post-reform UK landscape is five GB DNO ownership groups across fourteen licence areas, writing RIIO-ED3 business plans due December 2026 against a 4.35% allowed return. The reformed regime moves from theory to practice between July 2026 and March 2027.
Connections Reform converted a first-come-first-served queue into a CP30-aligned pipeline. About 140 data-centre facilities sit in the queue, aggregating to ~50 GW; roughly 13 GW is firm pre-2030, ~86 GW queued for 2030–2035. The post-reform pipeline is geographically concentrated — UK Power Networks, the M4 corridor, and Manchester / Slough / Cambridge hold the majority of strategic-demand pressure.
Distribution Gate 2 offers open early July 2026 (Phase 1) and run to mid-March 2027 (Phase 2). DNO business plans are due December 2026; the ED3 control period runs 1 April 2028 → 31 March 2033. Q3 2026 is the last meaningful window to influence regional priorities.
The shape of this volume. Section 1 sets out the headline figures. Section 2 develops twelve findings, each confidence-annotated. A chapter-weight pull at p. 14 anchors the argument. Section 3 sets out the reformed pipeline. Section 4 maps the five GB DNO groups. Section 5 isolates the RIIO-ED3 window. Section 6 sets out stakeholder implications, with a one-page tear-out at p. 26.
Connections Reform sorts the queue: 283 GW into Gate 2 (132 pre-2030 + 151 for 2030–2035), 216 GW into Gate 1, ~239 GW removed.
The CP30 deliverable envelope (ochre) is roughly a quarter of the pre-reform queue. Allocation, not generation, is the bottleneck.
HIGH — verified against a NESO, Ofgem, DNO or DESNZ primary source. MEDIUM — named UK industry coverage cross-referenced to a primary source. None is forward-looking opinion unless framed as such.
Findings 01 – 12 · summary
Findings 01 – 09 follow in detail · pp. 11 – 13 · 10 – 12 summarised on the matrix
The aggregate UK connections queue stood at over 738 GW pre-reform; the deliverable Clean Power 2030 envelope is approximately 200–225 GW. Even after Connections Reform sorts 283 GW into Gate 2 and 216 GW into Gate 1, more than 60% of queued projects will not hold a contracted connection date in the current decade. For any developer not yet inside the reformed pipeline the question is not when their connection comes — it is whether the project as currently scoped is still viable.
The 8 December 2025 NESO Connections Reform Results converted a first-come-first-served queue into a CP30-aligned pipeline. 132 GW of Gate 2 Phase 1 offers sit pre-2030, broadly matching the CP30 envelope of 200–225 GW. 151 GW of Gate 2 Phase 2 offers form the 2030–2035 build pipeline. 216 GW receives Gate 1 indicative offers — a route but no contracted date. The reform was negotiated with 60+ industry workgroups, 1,500 applications reviewed in five months, and 172 consultation responses.
With Iberdrola's August 2025 completion of an 88% stake in Electricity North West — rebranded SP Electricity North West — the historic six-group GB DNO map has consolidated to five. SP Energy Networks now operates three licence areas under one parent. Bidder maps written before August 2025 are out of date: commercial conversations in two of the historic six regions are now coordinated from one corporate centre.