Mayo Data Hub
A proposed €1.5bn data centre near Killala, County Mayo, Ireland.
On 17 September, Mayo Data Hub lost approval for its proposed €1.5bn data centre near Killala after An Coimisiún Pleanála overturned Mayo County Council’s 2025 grant.
Last refreshed: 24 September 2026
Timeline for Mayo Data Hub
Failed to show a fixed grid connection or renewable PPA
Data Centres: Boom and Backlash: Ireland refuses €1.5bn Mayo data centreBackground
Mayo Data Hub is a proposed data-centre development near Killala in County Mayo, Ireland. The scheme is backed by Avaio Digital and is intended to combine data-centre space with administrative buildings, electrical and mechanical plant rooms, and parking.
Its relevance rests on the practical demands of operating a large data centre: a secure electricity supply, grid capacity and a credible power plan. On 17 September, An Coimisiún Pleanála overturned local planning permission after finding that the project had no fixed grid connection agreement or significant onsite renewable generation.
The proposal illustrates how Irish planning decisions can turn on Energy infrastructure as well as the buildings themselves. Any future version of Mayo Data Hub will need to address the power and climate-planning concerns identified in the appeal decision.
Mayo Data Hub loses planning approval
On 17 September, An Coimisiún Pleanála refused Mayo Data Hub’s proposed development near Killala, reversing planning permission granted by Mayo County Council in 2025. The decision halted progress on the €1.5bn scheme at the national appeals stage.
The board found that the project lacked a confirmed grid connection and a renewable-power contract. Those gaps matter directly to Mayo Data Hub because power supply is central to whether the planned facility can secure consent and proceed.