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We recently summarised the National Energy System Operator’s (NESO) transmission connections reforms. NESO has now released a detailed timeline for the implementation of its connections reform programme, providing critical clarity for energy developers and network operators as part of the major restructuring of Great Britain’s electricity transmission queue.
NESO’s timeline is a landmark moment for connections reform and the upcoming evidence window is your best opportunity to secure a leading position in the reformed queue.
Key developer milestones
- 8–29 July 2025 – Evidence Submission Window (Transmission Projects)
Developers must submit maturity and readiness evidence within this three-week window to secure priority placement in the re-ordered connections queue. This window is the cornerstone of the “first-ready, first-connected” model NESO is introducing. - Weekly Support Sessions
NESO will host weekly webinars, backed by an updated Evidence Handbook and frequently updated FAQs, to support applicants through the evidence submission process. - Post-Window Queue Reordering
Following the July deadline, NESO will re-prioritise over 3,000 transmission queue projects based on submitted evidence, setting the stage for the issuance of new connection offers. - Autumn 2025 – Connection Offers Issued
Beginning in autumn, priority-ready, Clean Power–aligned projects can expect new connection agreements under the revamped framework. NESO aims to offer clarity to developers and their investors as early as possible.
Why early engagement is vital
NESO emphasises that active early participation is essential to prevent long delays further down the line. Prudent early submissions ensure developers are well-positioned for new connections. Given the volume of applications, NESO has made bespoke support (e.g., one-on-one advice) unavailable, so developers must take the initiative to engage with guidance materials and webinars. Furthermore, NESO will not make exceptions for missed deadlines during this period.
If you are a developer and would like support in navigating the connections reform programme timeline, please contact a member of our team.