Regulatory Other

On 29 August 2025, Ofgem amended a key Initial Project Assessment (IPA) condition for the three Third Window (W3) cap-and-floor electricity interconnectors granted regime-in-principle status in November 2024 — LirIC (to Northern Ireland), MaresConnect (to the Republic of Ireland) and Tarchon (to Germany). Citing external supply chain pressures and the resulting impact on project timelines and financing structures, Ofgem extended the IPA condition known as the "backstop date" from "operations prior to the end of 2032" to "operations prior to the end of 2035" (31 December 2035) for all W3 projects. The change means that if a project can no longer feasibly be operational by end-2035 ahead of the Final Project Assessment (FPA) decision, Ofgem may conduct an IPA review which could uphold or revoke the in-principle cap-and-floor regime. Ofgem stated that the extension is "consistent with our approach in previous windows" and is "proportionate given the nature of potential delay factors". The individual Regime Start Dates (RSDs) determined at IPA are not affected by this decision, so developers remain incentivised to limit delays; any future delay requests to the RSD will be assessed on their merits. The amendment effectively widens MaresConnect's regulatory schedule headroom by three years without altering its case-specific revenue parameters.