DISMANTLING and removing onshore wind farm infrastructure at the end of its operational life could be more harmful to the environment than leaving it in place, according to a new report published today.
The study, commissioned by government agency Scottish Natural Heritage (SNH), focuses on the benefits and drawbacks of restoring a site to its original state when a wind farm is decommissioned.
The report suggests that the removal of structures such as reinforced concrete turbine bases may have a more detrimental effect than leaving them in place.
According to the report: “There is a relatively low environmental risk associated with reinforced concrete that is left in situ.
“And the noise, ground disturbance and cost (excavation/breaking/processing/transporting), along with associated carbon emissions, may create a larger environmental impact than leaving in such concrete in situ.”
It warns that the complete removal of a concrete base without backfilling “would leave a sizeable void”, which could become a hazard.
It also recommends consideration of the “localised influence of the groundwater table associated with such filling”.
Restoring a site would bring its own carbon cost because of the construction work involved as this may require importing soils similar to the material removed.
Consent for onshore wind farms is usually granted for 25 years, and there are two options when a development reaches the end of its life: repowering and restoration; or restoration and decommissioning.
This report recommends that special consideration be taken when a site’s ground conditions are “dynamic”, such as in upland peatland environments, advising that “the decision to retain a buried structure should take into account the longer-term stability of the landform in order to avoid buried structures becoming exposed in the future”.
But campaigners from wind farm protest group Scotland Against Spin (SAS) said the study proves the Scottish Government knows its wind farm policy has been a “terrible mistake”.
SAS spokeswoman Linda Holt said: “The only way to ensure that there will be enough money in the kitty to pay for decommissioning and environmental restoration is for government to impose an immediate levy on all existing turbines.
“Developers of any new turbines should have to deposit cash for the full costs of decommissioning and restoration before a single sod is turned.”
Joss Blamire, senior policy manager at Scottish Renewables, said: “We hope this new guidance on the restoration and decommissioning of onshore wind farms will act as a crucial source of information in the industry’s efforts to develop and manage onshore wind projects.”