ESB to decommission Derrybrien wind farm’s 70 turbines

Peat slide in 2003 during excavation work for wind farm resulted in fish kill of 50,000

The Derrybrien wind farm in Co Galway is to be decommissioned, the ESB has confirmed.

An Bord Pleanála last month refused substitute consent to an ESB subsidiary, Gort Windfarms, for the wind farm and all works in response to the 2003 peat slide event at the site.

Following the decision, electricity generation at the site was paused by the ESB. The capacity of the wind farm was 59.5MW out of 5,600MW generated on the island of Ireland, which means it constituted about 1 per cent of installed wind capacity.

The decision to decommission the 70 turbines in the Slieve Aughty Mountains follows 20 years of controversy. Local people have long argued that aspects of the facility were problematic.


An ESB spokesman said it was “too early” to give any indication on costs associated with dismantling. He did not respond to questions on the overall cost of the failed project or whether ESB customers would ultimately bear the brunt.

Derrybrien wind farm was built in 2003 without an Environmental Impact Assessment (EIA) as Irish planning law did not require that EU standards apply.

A landslide during excavation work for the wind farm caused extensive environmental damage, resulting in the European Commission taking Ireland to court in 2008 – it ordered a retrospective EIA, but this was not carried out.

The landslide meant 450,000 tonnes of peat disturbed over an area of 25 hectares and resulted in the mass movement of 250,000 tonnes of material downslope.

Inland Fisheries Ireland told the appeals board last month that investigations after the peat slide indicated that about 50,000 fish died in an 18km stretch of river down to Lough Cutra.

The State has already amassed fines of €17 million as a result of an ongoing failure to ensure proper standards were adhered to at the Derrybrien development.

The fines, which were imposed by the European Commission in November 2019, include a €5 million penalty as well as a daily rate of €15,000, which the State was ordered to pay until compliance is achieved through the submission of a retrospective EIA for the wind farm.

A statement from the Department of Housing said: “The Department notes the decision announced by the ESB today. Further engagement with the commission will now take place to clarify the status of Ireland’s compliance with the CJEU [Court of Justice of the European Union] judgment.”

The ESB entity lodged the substitute consent application through a remedial EIA report in June 2020 in an attempt to regularise the project’s planning status.


The appeals board ruled that it was precluded from granting substitute consent to Gort Windfarms in the case after concluding that the significant effects on the environment from the project “were clear, profound and unacceptable”.

The board found that works undertaken by the applicants subsequent to the peat event and during the operation of the wind farm did not render acceptable the peat slide’s significant environmental effects.

The decision by the appeals board dismissed the recommendation of its own inspector to grant the substitute consent. Galway County Council had no objection to the granting of substitute consent.

In a statement on Wednesday, ESB said it was now preparing to decommission the 70 wind turbines at the site.

“ESB, through its wholly owned subsidiary Gort Windfarms Ltd, is to decommission the Derrybrien Wind Farm in Co Galway,” it said.

“This follows on from the decision of An Bord Pleanála on February 4th not to grant substitute consent. ESB consequently paused operation of Derrybrien. Following careful consideration ESB has now decided to decommission the wind farm. ESB will now prepare for the decommissioning of the 70 wind turbines in accordance with planning laws and regulations.”

Colin Gleeson

Colin Gleeson

Colin Gleeson is an Irish Times reporter