UK: Ofgem publishes TMO4+ decision

TMO4+ involves a gated process, through which NESO will make Gate 1 (indicative) offers to those projects not yet ‘ready’ or ‘needed’; and will make Gate 2 offers to projects that meet the Readiness and Strategic Alignment criteria.

The process is aligned with the UK government’s strategic plans, such as the Clean Power 2030 Action Plan. For projects able to come online during 2026 and 2027, the strategic alignment will ensure they are prioritised, with those that will be ready before 2030 being next in line.

Notable changes

The code modification proposals (CMPs) and Methodologies have largely been approved as expected. This gives industry the much-needed certainty it has been waiting for and gives a degree of certainty for those projects that are able to connect in time to help the UK achieve its Clean Power 2030 ambitions.

However, there have been some notable changes including:

• Ofgem’s view on the introduction of a pause in the process for applicants to ‘self-regulate’ the viability of their projects before NESO and the Transmission Owners carried out the network assessment. Although originally minded-to include the pause, in its confirmation Ofgem has approved the code modification proposals without this self-regulation pause
• Ofgem has recommended that NESO provide assurance to projects eligible for Protection Clause 2a which have existing agreements to connect on or before 31 December 2027, that they will retain connection dates and connection points. This is to ensure that those projects with existing contracts that support the Clean Power 2030 Action Plan are given maximum certainty as soon as possible that they will be eligible for Gate 2 contracts
• Ofgem has also recommended that Protection Clause 3 is simplified so that projects that submitted planning applications on or before 20 December 2024, and have not received a decision by the closure of the CMP435 application window, but receive consent after the application window closes are eligible to receive Gate 2 terms in a future window, even if this would breach zonal or national permitted capacities

Timeline for delivery

Ofgem has confirmed NESO’s proposed implementation timeline TMO4+:

• a 56-day standstill period for licence changes follows Ofgem’s decision (ending on 10 June 2025, on which date the Methodologies will come into effect), with a further 4-week notice period as required by CUSC
• Gate 2 evidence submission window is therefore expected to open 8 July 2025  (at the earliest) for transmission customers, and will open in May 2025  for distribution/IDNO customers
• NESO indicates which projects have secured a place in the reformed queue from September 2025
• revised offers to be issued from Autumn 2025 – focusing on projects with connection dates in 2026 and 2027
• 2030 connection dates will be prioritised, with all 2030 offers being issued by early 2026

Ofgem is treating these dates as backstop dates to ensure delivery in time to deliver the Clean Power 2030 ambitions.

Following this initial evidence submission window, NESO will work to open the next window for new applications before the end of 2025.