DecisionIrelandMayo
Appeal board refuses Mayo Data Hub's Killala data centre, citing no grid agreement and the Climate Action Plan
An Coimisiún Pleanála refused permission for Mayo Data Hub Limited's data centre at Mullafarry and Tawnaghmore Upper, Killala (case PL16.322575, council ref. 2460708), overturning Mayo County Council's grant of 25 April 2025. The order, signed on 15 September 2026, says the applicant failed to show a fixed grid connection agreement, existing grid capacity, significant on-site renewables or engagement with Corporate PPAs, and so failed to show consistency with the Climate Action Plan 2025 and the Government Statement on the Role of Data Centres. The scheme was a single building of about 29,076 m² with 25 backup generators. The decision followed the inspector's recommendation; the third-party appeal had been lodged on 21 May 2025.
Why it matters. A refusal resting on grid and climate grounds rather than local planning: on this reading, a data centre without a grid agreement and a renewables route can't clear ACP, whatever the council decided. The Grange Castle grant in the same month leaned on an existing EirGrid connection.
Our data confirmsOur lifecycle dataset already records the refusal (finalOutcome refused, 15 Sep 2026). At 482 days from appeal to decision it sits just above our median data-centre appeal of 462 days (n=16). /data-centres → /councils/mayo →
Sources: An Coimisiún Pleanála case PL16.322575 (order signed 15 Sep 2026), 15 September 2026 · Irish Examiner, 18 September 2026
Next, 10 November 2026: About eight weeks from the order: judicial-review window closes