The Green Party in Clare is to challenge a decision to grant a €1.2bn data centre, describing the development as "complete madness".
An Bord Pleanála has given the green light to contentious plans for a 200MW €1.2bn data centre campus on the outskirts of Ennis.
However, confirming her party would be seeking a judicial review following the board's decision, Green Party senator Róisín Garvey described the plans as "a joke".
Ms Garvey said the data centre would produce the same amount of emissions as 500,000 cattle each year and would prevent other development in the area.
The board this week upheld Clare County Council’s ruling to grant permission for the campus, which will comprise six data halls covering 145 acres or 1.3m sq ft on lands adjacent to the Tulla Road, near Junction 13 on the M18 motorway connecting Galway to Limerick.
Ms Garvey said: "We don't have the energy for these type of data centres, this data centre should not go ahead, it will not go ahead."
She told Clare FM the 200MW proposal is "way too big" and would not make use of renewable energy.
"EirGrid has said that the total capacity for Ennis available for its development is 80MW over the next 15 years.
Welcoming the decision, applicants Art Data Centres Ltd said the project would create between 400 and 450 permanent jobs when the data centre campus is fully operational, with up to 1,200 jobs in construction.
However, Ms Garvey completely rejected these long-term employment figures.
"If you go visit one you will see very few people working on the ground, apart from the construction, there are very few people working long term."
She added: "We are trying to move away from fossil fuels, this is backwards.
"The gas demand for this data centre is 1.5% of the entire country's annual emissions, which is equivalent to 500,000 cattle, so is this what we are going to do, forget about all farming, forget about all housing and focus on data centres? It's complete madness."
The planned Ennis data centre has been six years moving through various stages, including strategic site assessment, zoning, and planning.
The applicants initially pencilled for June 2023 as a construction start date, but opposition, along with planning delays at An Bord Pleanála, resulted in the appeals board taking more than 18 months to make a determination.
In giving Art Data Centres Ltd the go-ahead, the appeals board stated it had regard to the Government statement on the role of data centres in Ireland’s enterprise strategy from July 2022.
The board also said it has had regard to the Climate Action Plan and distance of the proposed development to dwellings in the area.