Derrybrien wind farm seeks to pack up, leaving 70 turbine foundations behind 

The taking down of controversial Derrybrien wind farm comes at the end of more than 20 years of legal wrangling.
Its removal from a Co Galway mountain will leave behind more than bad memories, though, as the foundations for its 70 turbines are to remain in the ground.

Gort Windfarms, the ESB subsidiary that owns the facility, recently held pre-application consultations with An Bord Pleanála to tease out preliminary issues before lodging a planning application for the required works.

It told planning officials it intended to apply to “remove the majority of aboveground features from the site – including all turbines, masts, electrical plant, overhead lines”.

It would also seek “retention in situ and in perpetuity of part of the existing development – including at and belowground structures such as turbine foundations and other foundations and substructures, on-site access tracks”.

In the case of Derrybrien, which gained notoriety when its construction caused a massive landslide in 2003, looking to leave the underground structures in place is not unexpected.

During the investigations that followed the landslide, it emerged no proper environmental impact study had been carried out, or indeed sought, by the planning authorities.

If it had, it would likely have warned against digging into the loose, wet, peaty soils of the Slieve Aughty Mountains to install and erect structures weighing hundreds of tonnes apiece.

“It would not be possible to remove turbine foundations without risk to ground stability,” an ESB spokesperson told the Irish Independent.

Martin Collins of the Derrybrien Action Group – which formed to represent local people whose land, property, roads and rivers were destroyed by the landslide – sees logic in that, but the move raises questions.

“There’s been no discussion with the community apart from a meeting last September when we were told by ESB what they were going to do,” he said.

“There was no discussion about whether it’s the best thing to do. We don’t know what it means for the mountain in the long term. We don’t know what aftercare is envisaged.”

Meanwhile, GE Vernova, owners of the country’s first and only offshore wind farm at Arklow Bank, announced in the past week that it was to be decommissioned.

It is expected, though not confirmed, that the company will also seek to leave the foundations in place in the seabed.

“We will work with local officials to progress the decommissioning process in a timely and responsible manner,” a spokesperson said.

These two wind farms will be the first to be decommissioned in Ireland, so there is no precedent to follow.

In other countries, various approaches are taken. The massive reinforced concrete bases could be dug up, broken up and taken away to reuse the steel within, but typically they are left behind, buried in the soil.

Offshore wind is a newer technology, so no pattern has formed around its afterlife.

The Department of the Environment said it was developing guidance, but that if any of the offshore wind projects currently in planning got permission, that would come with a “rehabilitation schedule” that would specify the works to be completed when operation ceased.

The Department of Housing, which oversees planning for onshore wind farms, said its guidelines advised that “decommissioning should involve the removal of all of the aboveground elements of the wind energy development and making good of the site, and that foundation pads can be covered with local soil and left for natural re-vegetation, except in highly exposed locations where they should be re-sodded”.

Industry body Wind Energy Ireland (WEI) said the key principle when decommissioning was “minimising any additional environmental impact and restoring the land”.

A study it commissioned last year said one-fifth of all wind farm capacity would reach the end of their operating licence by 2030, so in theory, that could mean a lot of sites to be “made good”.

However, WEI is pushing for the extension of licences or “repowering” – a move the Government backs – which would kick the question of aftercare further down the road.

Eventually, though, many will have to be decommissioned, particularly when turbines wear out, as new models are much bigger and unsuited for 30 year-old-foundations.

Jerry Mac Evilly of Friends of the Earth said repowering should be an option where possible, but otherwise, consideration should be given to keeping sites as clean energy facilities in some other way – perhaps converting to solar.

“Failing that, they could be rewilded or restored for ecotourism, but what we’d really like to see is the sites handed over to community-owned energy projects,” he said.