PLANS FOR A data centre in Co Mayo have been overturned by An Coimisiún Pleanála, partly because the operator was found to have failed to show there is “existing capacity” in the electricity grid to handle the added pressure of the system.

The contentious plans had been originally opposed by international best-selling author Sally Rooney, who warned of “wasteful consumption of electricity” that would push energy prices higher if approved.

The data centre was approved by Mayo County Council last year but, following an appeal, An Coimisin Pleanála has now overturned the council’s decision for Mayo Data Hub Ltd at Mullafarry and Tawnaghmore Upper, Killala.

The company behind the €1.5 billion development is Mayo Data Hub Ltd, which is part of US-based Avaio Digital.

The data centre – located 1.8km to the south of Killala and 10.5km to the north of Ballina – was to require 50MW average electrical power to operate.

The commission examined the case after retired scientist Colin Doyle, from Ennis, Co Clare, had lodged the third party objection.

Doyle had previously stated that his main concern was indirect greenhouse gas emissions (GHG) generated by the data centre and the resulting impact on climate.

In the summary of its ruling, seen by The Journal, the planning commission said it completed an environmental impact assessment for the proposed development and concluded that the project relies to a large extent on the electricity sectoral ceilings being met and net-zero decarbonisation of Greenhouse Gas (GHG) emissions by 2050 as committed to in the Programme for Government and set out in the Climate Act 2021.

“It is considered the applicant has failed to demonstrate that the proposed development would be in accordance with the overarching objectives of the Climate Action Plan 2025,” An Coimisin Pleanála said.

The company had planned on having backup generators using fossil gas and biodiesel for the data centre.

While the commission noted there are a number of renewable wind energy projects near the site, it ruled that the developer had “not provided any evidence that the proposed development could avail of locally generated renewable power for the development and that there is sufficient capacity in the grid to service the development”.

It added that the project did not appear to have any long-term contract with a renewable energy supplier.

In an interview with the Western People local newspaper last year, Avaio Digital said that roughly 300 jobs were expected to be created during construction.

When complete, 30 to 35 full-time jobs were expected to man the data centre.

Meanwhile, in her own objection, Rooney told the council that she was making her submission “as a resident of County Mayo and a concerned citizen”, and urged the council to refuse planning permission for this “wasteful, unnecessary and environmentally toxic proposal”.

“Climate change represents an immediate and unprecedented threat to our way of life here in Mayo and to the future of human life around the world,” the Normal People and Intermezzo author said at the time.