The UK has initiated the most substantial reform to its grid connection process in decades, replacing the long-criticised first-come, first-served system with a model that prioritises projects that are genuinely ready to build and strategically aligned with the clean energy targets.

NESO, the National Energy System Operator, has established a curated project pipeline, immediately progressing 283GW of clean generation and storage and nearly 100GW of new or expanded transmission-connected demand.

The previous queue had swollen to around 700GW, four times Great Britain’s projected needs for 2030, with many “zombie projects” blocking shovel-ready developments.

Under the new model:

  • 132GW of projects directly support the Clean Power 2030 target and will progress first.
  • An additional 151GW are positioned as essential for the system by 2035.
  • Over 300GW will not proceed in this allocation round due to lack of readiness or misalignment with national objectives.

Government, Ofgem and NESO leaders all describe the overhaul as a transformative moment for grid access, expected to unlock billions in clean energy investment and significantly reduce connection delays.

Implications for Large Energy Users (LEUs)

Greater Certainty Over Connection Timelines

NESO’s prioritisation framework gives large energy users, including industrial plants, manufacturers, electrified transport hubs and data-heavy facilities, clearer visibility on when they can expect transmission access.
Around 12% of major demand projects will receive 2030 connection dates; the remainder fall into a structured 2030-2035 horizon.

Outcome: LEUs can now align investment, construction, procurement and financing decisions with more reliable power-availability forecasts.

Competition Intensifies for Early Transmission Capacity

As only a small fraction of demand-side projects are advancing this decade, LEUs face a more competitive landscape. Readiness (land rights, planning permission, engineering maturity) now determines priority, not queue position.

Outcome: Businesses must accelerate early-stage development and demonstrate deliverability to secure near-term connections.

Potential for Interim or Hybrid Energy Approaches

LEUs whose projects fall into later delivery windows may need to explore alternative power strategies, including:

  • On-site solar or embedded generation
  • Behind-the-meter batteries
  • Private wire arrangements
  • Phased site expansion

Outcome: Energy strategy becomes more dynamic, with hybrid supply models emerging to maintain growth.

Financial and Commercial Risk for Deprioritised Projects

Projects not progressed may encounter contractual, planning or investment challenges. Some developers may consider legal recourse, given the scale of the reform.

Outcome: LEUs need scenario planning and risk-mitigation frameworks to protect commercial commitments.

Opportunities for Flexible and Strategic Large Users

The new framework favours projects that can adapt their demand or support system stability.

Outcome: LEUs with flexibility, storage or controllable load are better positioned to secure improved connection terms in future queues.

Joseph Letras, Sustainability Director at ARO, added:

“These connection reforms signal a fundamental reset in how the UK allocates scarce grid capacity. For large energy users, it places a premium on readiness, credibility and flexibility. The companies that succeed will be those willing to invest early, innovate in their energy strategies and demonstrate that they can support (not strain) the future electricity system.”

The overhaul represents a decisive shift toward a grid connection system that rewards readiness and alignment with national objectives. For large energy users, it brings much-needed clarity, but also new pressures to accelerate planning, adopt hybrid energy strategies and demonstrate credible delivery pathways.

ARO can help you navigate the new grid reforms by assessing your readiness, shaping robust energy strategies and positioning your project for early connection. Get in touch to ensure your organisation stays competitive under the new priority framework.