Planning permission for a 14-turbine wind farm between two villages in Cork and Kerry has been quashed by the High Court over its potential impact on the hen harrier.
Mr Justice Denis McDonald granted the order to the Sliabh Luachra Against Ballydesmond Windfarm Committee over the November 2018 Bord Pleanála permission to Silverbirch Renewables for the wind farm on elevated ground between Gneeveguilla in Kerry and Ballydesmond in Cork.
Silverbirch and Kerry Co Council, which had refused planning permission, were notice parties in the case.
The committee claimed, among other things, there had been a failure to carry out an appropriate assessment or environmental impact assessment in accordance with national and European law.
Concerns were also raised over the impact of the development on the hen harrier and freshwater pearl mussel due to effects on water quality of the River Blackwater which is near the site.
The board and Silverbirch opposed the challenge.
Mr Justice McDonald found the committee's case in relation to the freshwater mussel had not been made out.
However, he said it succeeded in relation to the hen harrier to the extent that it was unclear from the Bord Pleanála inspector's report how a conclusion could have been reached that all of the potential impacts on the bird had been satisfactorily resolved during the assessment stage.
He quashed the decision and will hear later from the parties as to whether it should be sent back to the board for reconsideration.