AN alternative peatland restoration method has been undertaken at Golticlay Wind Farm in Caithness.
The wind farm is being delivered by Farrans on behalf of RWE, with one of the most significant challenges facing the project team being the management and restoration of peat found across the site.
Peatland habitats play a vital role in carbon storage and biodiversity, making their protection a key consideration throughout the development and construction of renewable energy infrastructure.
Recognising the environmental sensitivity of the site, Farrans worked with its client during the early stages of the project to develop a peat management plan (PMP). This detailed how peat would be excavated, handled, stored, and reinstated across the site.
Given the importance of the peatland habitat, the PMP and wider strategy underwent consultation and review with key stakeholders – including NatureScot and Peatland Action – before being approved. All excavated peat has been retained on site, Farrans said.
The management of excavated peat on the Golticlay site involved the implementation of an innovative technique, aimed at integrating the excavated peat within the peatland habitat restoration operations, as a new, sustainable ways to valorise the peat resource on wind farm sites. The ultimate goal of the technique is to achieve the restoration of degraded peatland habitats in areas immediately adjacent to the wind farm infrastructure on previously forested sites.
This involved integrating excavated peat within the traditional ground smoothing operations to raise the local water table and establish hydrological conditions which favour the revegetation of peat-forming species and re-functionalisation of the excavated peat. The technique also minimises peat handling and storage time and reduces the environmental impacts of excess peat handling and the drying of peat stored for long periods of time, Farrans explained.
The technique has been based on pilot-scale trials completed at the Camster 2 Windfarm by RWE in partnership with FLS and with the support of Farrans. The learnings from the pilot-scale trial helped optimise and shape the methodology used at this full-scale trial.
RWE and University of Highlands and Islands (UHI) have entered in a knowledge transfer partnership (KTP) where a grant funded KTP associate will undertake detailed monitoring of the pilot-scale & full-scale trial areas. If successful, this technique will be further refined and more widely adopted across the industry.
Farrans explained that suitable locations for implementation were identified based on the review of local topography and hydrology, favouring areas where the peat would remain saturated and avoid drying out. In particular, the technique involved the stripping and retaining of existing turves, treatment of the tree stumps to break the linear ridges/furrow features, infilling of the area with freshly excavated peat and the placement of the existing turves over the infilled area.
Area 7 is the largest area on site where the full-scale trial has been implemented, covering approximately 43,000m². Around 40,000m³ of peat was placed within this area alone. To facilitate the movement of material to these restoration areas, temporary spur roads were constructed allowing trucks to transport peat beyond the main access routes.
Once placement was complete, the previously retained turves were positioned and graded to promote rapid regeneration and preserve the site’s natural vegetation.
The earthworks phase has been predominantly undertaken by Farrans’ subcontractor, Gow Groundworks, whose team has played a key role in delivering this challenging element of the project.
Construction at Golticlay Wind Farm continues to progress well, with the first blades recently arriving at site and turbine erection works scheduled to commence later this summer.
