Scotland’s countryside faces being littered with the concrete bases of wind farms that have been dismantled at the end of their operational lives, a major study has warned.
Research commissioned by Scottish National Heritage (SNH) found that removing the reinforced concrete could cause more environmental damage than leaving the bases where they are.
Although the structures could be covered up with topsoil and pose a “relatively low” environmental risk, the report warned some may be susceptible to “oxidising and subsequent staining/contamination.”
Detailing the method for removing old turbines, the 112-page report said this required cranes, excavators, dump and tipper trucks, along with a hydraulic breaker or explosives to remove the base.
The study said wind farm companies could also decide to leave behind access tracks, cabling and pads on which the cranes are erected for stability if these are considered too damaging to dismantle.
Alternatively, new wind farms could be erected on the same site. Scotland has yet to experience much decommissioning because turbines have a lifespan of around 25 years and most have been erected relatively recently.
SNH, the country’s nature quango, said it would use the findings to draw up guidance for wind farm companies but the Tories said the report showed turbines will scar the countryside long after the turbines have stopped working.
Struan Stevenson, a Conservative MEP, said: “To say you can restore the landscape to its original beauty is utter nonsense.”
The study said retaining wind farm infrastructure would lead to “adverse” effects on the landscape, including the “loss or alteration” of key characteristics.
However, their demolition and removal can lead to damage to habitats and vegetation and result in piles of “temporary excavations” and “storage” mounds out of character with the area.
“The complete removal of a concrete base without backfilling would leave a sizeable void that could become an unwanted water feature, or even a hazard, if not backfilled,” it said.
The study warned that peatland, on which many wind farms are built, is particularly likely to be harmed by the retention of a “buried structure”.
The average wind turbine foundation is between 12,360 cubic feet and 15,892 cubic feet of concrete, the report said, and contains between 45 tons and 70 tons of steel rebar.
Karen Taylor, SNH’s renewables and advice officer, said: “The report will help developers of future wind farms to build them with decommissioning in mind. Knowing how they will remove it will help inform how they will build it.”
Scottish Renewables, representing wind farm companies, said the guidance would act as a “crucial source of information”.