An ordered queue: reform of the GB grid connections process

On 10 June 2025, the set of reforms to the electricity grid connections process – referred to as "Connections Reform" (or the TMO4+ reforms) – went "live". This followed the 15 April 2025 approval by the regulator, Ofgem, of the industry code and licence condition modifications, as well as associated documents, that implement the significant reforms to the grid connections process that have been taken forward by the new National Energy System Operator (NESO). Connections Reform is intended to address the connection delays that resulted from the former "first come, first served" connection applications model, and achieve the goals set out in the Government's Clean Power 2030 Action Plan (CP30 Action Plan). Significantly, Connections Reform has implications not just for new connection applicants, but also for most projects that currently hold a connections offer to connect to the transmission or distribution system.  

In this briefing we set out a summary of the key elements of the reforms, implications for different categories of projects and the timetable for implementation of the reforms.

The new regime in a nutshell

Under the new grid connections regime most projects seeking a new connection (or a modification to an existing connection) to the transmission or distribution system will no longer be able to apply at any time to secure a place in the connections queue. Instead, there will be set application windows. To secure a place in the queue, applicants will need to meet certain Gate 2 criteria. Applicants that are unable to satisfy the Gate 2 criteria may be eligible for a Gate 1 connection offer, which serves to provide only indicative connection details.

The Gate 2 criteria, set out in the Gate 2 Criteria Methodology, are made up of two elements:

• Gate 2 Readiness Criteria; and
• Gate 2 Strategic Alignment Criteria.

The only projects not impacted by Connections Reform (referred to by NESO as "out of scope") are: 

• existing connected parties that have already energised;
• demand projects seeking a connection to the distribution system; and 
• generation projects seeking a connection to the distribution system that do not require Transmission Impact Assessment (TIA) (as these have no significant impact on the transmission system). The TIA threshold applying in England and Wales was recently raised from¹ 1MW to 5MW, but remains 200kW in Scotland South and Scotland North. However, even though the general threshold was raised to 5MW for England and Wales, there may be some projects below 5MW but at 1MW or above that are impacted because the relevant Grid Supply Point (GSP) does not have sufficient fault level headroom.²

Before the enduring arrangements commence, NESO will carry out a one-off exercise – the "Gate 2 to Whole Queue" (G2TWQ) process – to determine which projects that currently hold a connection offer satisfy the Gate 2 criteria.  Following the G2TWQ process, projects that have been subject to it will receive either a Gate 2 offer or a Gate 1 offer.

Recognizing that the G2TWQ process will apply retrospectively to many connection offer holders, projects that currently have a connection offer and that fall within certain exceptions or "protections" (set out in more detail below) will be considered to satisfy the Strategic Alignment Criteria.

In terms of the general architecture of the new regime, the following are its key elements:

• amendments to the Connection and Use of System Code (CUSC), through code modification CMP435, to implement the G2TWQ process (primarily through a new section 18 of the CUSC);
• amendments to the CUSC, through code modification CMP434, to implement the enduring arrangements (primarily through a new section 17 of the CUSC);
• amendments to the System Operator Transmission Owner Code, through code modification CM095;
• three new documents (referred to as methodologies) which NESO is now required to maintain pursuant to its licence. These are: 
  
  • the Gate 2 Criteria Methodology;
  • the Project Designation Methodology; and 
  • the Connections Network Design Methodology; and
• associated licence condition amendments.

NESO has published a full timetable for implementation of Connections Reform on its website.³ The key dates from that timetable are as follows.

Transitional Offers

In preparation for implementation of the new regime, since 2 September 2024, any new applications for a direct connection to the transmission system received a so-called "Transitional Offer". These Transitional Offers have been similar in nature to the "Gate 1" offers being introduced as part of the connections reforms (see below). In particular, Transitional Offers have only included an indicative connection date and an indicative connection location. As the application will not have been studied, no reinforcement works have been included or associated securities required.

The Transitional Offers process was not applied to BEGA, BELLA or modification applications.

The application "pause"

On 15 January 2025 NESO announced a "pause" on accepting new applications from 29 January 2025 (subject to some exceptions). The pause no longer applies, although, as explained below, under the new regime, projects within the scope of Connections Reform (that do not already hold an offer) will have the next opportunity to apply for a connection when the second Gate 2 window is opened by NESO.

The Gate 2 Readiness Criteria

The applicant, through a Readiness Declaration, will be required to provide evidence that the project is "ready" by demonstrating compliance with the Readiness Criteria, which can be demonstrated through one of the following two routes: the project acquiring appropriate land rights or going through the Development Consent Order process – as summarised in Figure 1. The full details are set out in the Gate 2 Criteria Methodology. These two possible ways of satisfying the Gate 2 Readiness Criteria are also described as the "land route" and the "planning route".

Figure 1: Gate 2 Readiness Criteria

The Gate 2 Strategic Alignment Criteria

The Government's CP30 Action Plan plays a key role in establishing the Strategic Alignment Criteria.  

The Connections reform annex of the CP30 Action Plan sets out the capacity ranges for the main technologies that are expected to be deployed to allow the clean power objectives to be met, and which will therefore inform the prioritisation of projects for grid connection. As well as setting out the capacity ranges for the period up to 2030, the annex also sets out indicative capacity ranges for the period up to 2035. See Figure 2 below for the 2030 capacity ranges.

Figure 2: 2030 capacity ranges

For most projects (in particular, the technologies covered by the CP30 Action Plan), the primary way of satisfying the Strategic Alignment Criteria will be through alignment with the generation technology capacities set out in the CP30 Action Plan – in effect, by fitting within the relevant "technology pots", as described in more detail in Figure 3. However, there are also other ways that projects can satisfy the Strategic Alignment Criteria, including protections for projects currently being progressed.  

The different routes to satisfying the Strategic Alignment Criteria are summarised in Figure 3, with full details set out in the Gate 2 Criteria Methodology.

Figure 3: Routes to satisfying the Strategic Alignment Criteria

The CP30 Action Plan, first published in December 2024 and updated in April 2025, will in the future be replaced by longer-term plans for the GB energy system, as summarised in Figure 4. Significantly, the Infrastructure and Planning Bill (currently before Parliament) includes provisions which explicitly link the connections process to strategic plans designated by the Secretary of State pursuant to regulations contemplated by the Bill.

Figure 4: Longer-term energy plans

Gate 2 to Whole Queue

As mentioned above, the G2TWQ assessment process will commence in July 2025.  The Connections Network Design Methodology sets out details of how the G2TWQ process will be carried out.  At a high level, the process will involve the following:

• projects are eliminated if they do not meet the Gate 2 Readiness Criteria or have not been selected for Connection Point and Capacity Reservation (a process by which NESO may reserve connection points and capacity for certain projects – e.g. CATOs);

• remaining projects are eliminated if they do not meet the Gate 2 Strategic Alignment Criteria. Depending on when the relevant projects are able to connect, they will either be considered against the 2030 phase or the 2035 phase. NESO will maintain the existing relative queue positions of projects that align to the 2030 phase. For the 2035 phase, preservation of the original relative queue order is seen as less critical, because the programme of works required to connect these projects will likely require more revision;

• as part of the G2TWQ process, capacity will be "freed up" by projects that have not met the Gate 2 criteria being removed from the queue. Therefore, alongside submitting evidence that they have met the Gate 2 Readiness Criteria, projects can also submit a modification application and request that their project is considered for advancement as part of the G2TWQ process, as well as changes to their point of connection;

• Gate 2 offers (which will be "Gate 2 modification offers" in the context of G2TWQ) will be issued by NESO in batches, to successful projects. To retain their Gate 2 offer, projects will then need to continue to comply with the conditions of the offer, including any milestone requirements, to avoid termination. The User Progression Milestone process has been aligned with Connections Reform, as reflected in NESO's updated Queue Management Guidance;

• projects that have not been successful in securing a Gate 2 offer will:

  • have their security returned to them; and

  • be issued with a Gate 1 offer (see below) via an Agreement to Vary;

• for small and medium embedded generators, NESO will issue a Gate 1 offer to the DNO and the DNO will then issue a "Distribution Gate 1 offer" to the customer, that reflects the NESO Gate 1 offer.

The enduring arrangements

Following the one-off G2TWQ process, NESO will hold Gate 2 application windows twice a year.

Projects that are unable to satisfy the Gate 2 criteria at the time of application will also have the option of applying for a Gate 1 offer instead.

Nature of a Gate 1 offer

A Gate 1 offer will include only an indicative connection date and an indicative connection location (unless the project is selected for Connection Point and Capacity Reservation).  Importantly, an application for a Gate 1 offer is not a prerequisite to a subsequent application for a Gate 2 offer.

Implications for connections to the distribution system

For small and medium embedded generators, DNOs will carry out initial checks on whether projects satisfy the Gate 2 criteria and will then follow a process largely based around the Project Progression process that currently applies. The Statement of Works process is being removed, with Transmission Evaluation being introduced as a route for a DNO to request an Evaluation of Transmission Impact. DNOs will submit a Transmission Evaluation Application to NESO on behalf of their embedded customers, within the Gate 2 application window. The application can contain multiple embedded generator projects or one submission per embedded generator project.

Importantly, for small and medium embedded generators, the NESO will be making the Gate 2 or Gate 1 offer (as the case may be) to the DNO, which will then be reflected in the offer made by the DNO to the relevant customer.

Large embedded generators will be able to apply for a BEGA/BELLA Gate 2 offer throughout the year, but the DNO will still need to submit a modification application (for transmission assessment) in the Gate 2 application window.  NESO will verify whether a project has met the Gate 2 criteria as part of processing of the BEGA/BELLA application.  If a large embedded generator wishes to receive a Gate 1 offer prior to having met the Gate 2 criteria, it must submit the BEGA/BELLA application to NESO in the Gate 2 application window, but no modification application is needed from the DNO – the large embedded generator will receive a Gate 1 offer from NESO based on their BEGA/BELLA application.

New Progression Commitment Fee

As part of Connections Reform, NESO has also been considering the introduction of a new requirement for Gate 2 offer holders to provide financial security, to further signal their commitment to progressing their project.  NESO published a "call for input" on these proposals in November 2024.

Following this call for input, NESO raised a new CUSC modification (CMP448) to introduce a Progression Commitment Fee (PCF) that will support future connections in the queue. The PCF will only apply to generation projects that have already progressed through the first stages of the connections process to join the future Gate 2 connections queue but have not yet initiated statutory consents and submitted a planning permission which is a requirement of Milestone 1 (which is one of the "User Progression Milestones" referred to above). 

Under the proposals, NESO has indicated that the PCF will remain dormant unless a metric, which is indicative of the health of the connections queue exceeds a defined threshold. The proposed PCF applicable to a project will have an initial value of £2,500/MW, increasing at a rate of £2,500/MW at 6 monthly intervals up to a maximum of £10,000/MW for any individual project.  Projects will be liable for the full value of their PCF upon termination of the project (or the appropriate portion of the PCF upon reduction of capacity) prior to successfully demonstrating achievement of Milestone 1.

If the PCF is activated, developers of projects between Gate 2 and Milestone 1 will be required to post a security against the PCF, the “Progression Commitment Fee Security” (PCFS). The PCFS must remain in place until the developer successfully demonstrates that the project has achieved Milestone 1. After achieving Milestone 1, developers will no longer be subject to the PCF if they terminate and there will no longer be a requirement to secure against the PCF. 

This modification has been approved as "urgent" by Ofgem, meaning that it can follow an expedited timetable.  It is proposed to be implemented prior to applicants having to accept their Gate 2 offer.

All existing connection offer holders, as well as future applicants, need to familiarise themselves with the new regime.  This is particularly important for existing connection offer holders who will need to submit an application as part of the G2TWQ window – these projects need to be ready to submit their application to the relevant DNO or NESO (as the case may be).  NESO is currently holding various industry webinars and has published various guidance on the process on its website.

This is an updated version of a briefing previously published in February 2025.

Authors: Justyna Bremen, Counsel; Antony Skinner, Partner; Hannah Roberts, Associate