Grid Connection Queue Reform (TMO4+) Approval: Key Points to be aware of

Overview

On 15 April 2025, Ofgem (as anticipated) approved the significant and well publicised electricity grid connections reforms known collectively as TMO4+ (including CMP434 (implementing reforms to new applicants) and CMP435 (implementing reforms to the existing connections queue)). Please see our previous posts for further background (links here and here).  These radical and far-reaching reforms have the effect of moving the GB electricity grid connection process for almost all electricity generation projects and transmission connected demand projects from a “first come, first served” approach to a “first ready, first needed, first connect” approach and are of huge significance to the electricity industry.  

This post is not a summary of the TM04+ Reforms but is intended to highlight some of the notable amendments suggested by Ofgem in its approval decision and direct attention of affected parties to some key dates and documentation which are of relevance if applying for a Gate 2 Offer. 

Key Dates

Ofgem’s decision has triggered a 56-day standstill period (expiring 10 June 2025) before all relevant TM04+ codes, methodologies and licence changes “go live”.  Thereafter, NESO is required by the CUSC to provide a 4-week notice period ahead of the Gate 2 CMP435 application window opening. 

Applying these dates generates the following anticipated timeline with the exact dates being confirmed by NESO in due course:

Key Points in Ofgem’s Publications

Whilst the majority of the TMO4+ policy proposed by NESO has been approved by Ofgem without amendment (including the Project Design Methodology and Connections Network Design Methodology), some important amendments have been proposed to the Gate 2 Criteria Methodology:

• Under current methodology, projects that fall under Protection Clause 2a (Projects which are significantly progressed (CMP435)) are not guaranteed a connection date or point of connection (PoC) but are guaranteed a Gate 2 Offer (subject to readiness criteria being met).  Protection Clause 2a currently applies to (i) projects which have submitted a planning application on or before 20 December 2024 (that was subsequently validated) and achieve planning consent before closure of the CMP435 application window; (ii) projects that hold a support contract (CfD or Capacity Market Agreement); (iii) projects that have regulatory approval from Ofgem in the form of either an LDES, Interconnector or OHA Cap and Floor agreement or Merchant Interconnector approval; or (iv) projects that hold a live “Network Services” contract.  Ofgem has proposed extending the protection afforded under Clause 2a such that projects with an existing connection agreement providing a connection date on or before 31 December 2027 should retain their existing contracted connection date and point of connection (PoC).   This is a very welcome development for some developers but the detail will be important to understand.  For example, how will this change affect projects that fall within Protection Clause 2a but which have a current connection date after 2027?  Whilst these projects will be guaranteed a Gate 2 offer (subject to readiness criteria being met), there will be no guarantee of connection date (or indeed of a connection before 2030) or PoC.  We already know that the permitted CP30 capacities for some technologies in specified zones is likely to be exceeded many times over by those projects due to connect in 2026 and 2027 and which will likely benefit from Protection Clause 1 (Projects connecting by end 2026) or Protection Clause 2a (if Ofgem’s proposal is accepted), so developers due to connect after 2027 will be anxious to learn of the impact of Ofgem’s proposed amendment on their connection terms.
• Ofgem recommending that Protection Clause 3 (Projects which obtain planning consent after closure of the CMP435 Gated Application Window (those who reapply in CMP434 only)) is simplified to provide those projects which:

1. submitted planning on or before 20 December 2024; 
2. have no planning outcome by the closure of the CMP435 application window; and
3. achieve planning consent after the closure of the CMP435 application window,

are eligible to receive a Gate 2 offer in a future CMP434 window even if this would breach zonal or national permitted capacities.   The language at paragraph (ii) above contrasts with the current wording of Protection Clause 3+ (appeal) which requires a project to “obtain a refusal or non-determination” before closure of the CMP435 window.  Ofgem recognises that this could inadvertently prejudice projects that are caught within a planning system that does not have statutory timescales that would guarantee a “refusal or non-determination” before window closure and have therefore sought to amend the language accordingly.  We assume that Ofgem’s proposal is limited to Protection Clause 3+ (appeal) and is not intended to be a replacement of the wider Protection Clause 3 which applies to projects that (i) meet the Gate 2 readiness criteria; (ii) have submitted (and had validated) a planning application before closure of the CMP435 application window (but after 20 December 2024); and (iii) secure consent after the first Gate 2 window closure – in this scenario, a Gate 2 Offer would be guaranteed should the project reapply under a subsequent CMP434 application window subject to national permitted capacities not being exceeded.   However, it will be important to review any consequential amendments introduced by NESO to the Gate 2 Criteria Methodology to confirm that our assumption is correct as applying an earlier application date of 20 December 2024 to the whole of Protection Clause 3 (and not just Clause 3+ (appeal)) would likely have material repercussions to those developers seeking to submit an application ahead of window closure.   

NESO is currently reviewing the above two proposals and will need to make any required changes to the Gate 2 Criteria Methodology by 30 April 2025. 

Furthermore, NESO had previously proposed a “pause” in the CMP435 Gate 2 application process after projects’ readiness checks had been completed but before completion of the strategic alignment checks.  This was intended to enable NESO to publish a register (WACM1 Register) detailing which projects had fulfilled the readiness criteria (including PoC, completion date, installed capacity and technology type) to enable applicants to reflect on their project’s likely prospects and make an informed decision on whether to continue with their application, thereby introducing a form of market self-regulation.  Ofgem has rejected this “pause” but has retained the requirement for NESO to publish the WACM1 Register as a means of improving transparency in the connections process.  As such, developers will need to think very carefully about their Gate 2 applications at the outset as the (limited) opportunity for an applicant to adjust its Readiness Declaration during the “pause” (including seeking an advancement not previously requested) will no longer apply.  

Key Documentation 

Parties intending to apply for a CMP435 Gate 2 Offer should be aware of the following documents:

• The approved Gate 2 Criteria Methodology (subject to the amendments referred to above)
• The approved Project Designation Methodology
• The approved Connections Network Design Methodology
• The Readiness Declaration Template – this draft template was published on 15 April (including handy tips) and is critical for Gate 2 applications.  

Wider Context and Practical Steps

We now move into the implementation stage of the connection reforms and the huge task for developers, NESO, DNOs and iDNOs of submitting and assessing Gate 2 evidence and issuing new grid connection documentation (where applicable). 

Reflecting this, we recommend that all affected generators and developers of transmission connected demand projects start collating their Gate 2 evidence now (and get land arrangements in place where relevant), review the form of Readiness Declaration and start thinking about their proposed Gate 2 submissions in respect of their projects. Potential investors and funders of projects due to connect in 2026, 2027 and later may also want (to the extent they have not already done so) to start scrutinising proposed Gate 2 submissions and the likely impact of these reforms on the relevant projects.   

We are currently helping a large number of clients assess the impact of and navigate these grid reforms so if you need any assistance please contact James Phillips, Alec Whiter, Ross Fairley or Nick Churchward.

This article was written by Rosie Lord and Alec Whiter.