Viking had many challenges to overcome, including how best to ensure minimal impact on the environment in Shetland.
Building wind farms is an important part of decarbonising our energy system and in helping meet our collective net zero targets. But this can't be done by ignoring the environment in which we are going to build and operate them.
During the development phase, considerable work was undertaken by experts in their respective fields who surveyed, assessed and reported on the potential impacts of building Viking. This work formed part of the planning process and the outputs from the various reports helped inform the various planning applications that have been submitted over the years.
The information helped inform key stakeholders and the planning authorities on whether a wind farm should be consented and, if it is consented, the types of mitigation that would be required during Viking's construction and operational phases.
A Construction Environmental Management Plan (CEMP) was developed for the construction phase and a Habitat Management Plan (HMP) has been developed and agreed by key stakeholders containing information on how certain issues will be managed during the operational phase and what long term (often for the full life of the wind farm) obligations must be met.
The Habitat Management Plan (HMP) , covering several thousand hectares was agreed as part of the consent awarded in 2012. It contains plans to restore degraded areas of peatland around and beyond the wind farm site and to seek to protect bird species such as whimbrel, red-throated diver and merlin.
In January 2020, a detailed implementation plan for the HMP was approved by Shetland Islands Council, following approval by Scottish Natural Heritage and the Scottish Environmental Protection Agency.
An indepedent Environmental Clerk of Works (ECoW) has been employed to oversee construction activity with the power to stop works where issues are identified.
The following section contains more information about some of the issues and subsequent mitigation.
The Viking wind farm is home to many species of birds including species of high conservation value including red-throated diver, whimbrel and merlin. From the earliest stages of development, the Viking team have worked tirelessly to ensure that the development, construction and operation of the wind farm would impact on local and breeding bird populations as little as possible. Indeed, the implementation of the Habitat Management Plan (HMP) will see extensive restoration and protection of degrading blanket bog, which in turn will benefit birds and other species.
Extensive studies of bird populations and flight paths have been carried out by Viking and assessments have continued throughout construction which has led to the locations of turbines and other infrastructure being kept away from important breeding lochs and avoiding regularly used flight corridors and the appointment of an independent ECoW (Environmental Clerk of Works) put in place additional safeguarding for our avian neighbours during construction.
As the infrastructure has been installed, our teams have noted that ground nesting birds have quickly become accustomed to its presence and have opted to keep their distance and we've seen successful breeding from great black gulls near to a recently installed turbine. A regular pair of merlin set up a nest in close proximity to the location of three turbines and whilst they seemed not concerned with activity, we decided to postpone the installation of the turbines until after the young had fledged to avoid disturbing them. Four chick were successfully fledged and subsequently ringed in the usual way by the local birding community.
The Viking wind farm is situated in an area of extensive peat bog which is ordinarily plays a significant role in storing CO2 emissions. But some of the Viking site contains degraded and exposed peat which means that it is in fact emitting CO2 back in to the atmosphere.
As part of the Viking Habitat Management Plan (HMP), SSE Renewables will work to restore large areas (over 260Ha) of degraded peat and protect other areas from further erosion and seek to arrest further loss of carbon dioxide to the atmosphere. This will be done in partnership with key stakeholders and local experts including Shetland Peat Restoration (SPR).
During construction, peat excavated for roads and turbine bases will be reused and extensive measures were taken to prevent hill peat drying out which included drainage control and the restoration and creation of small lochans to keep it waterlogged. Floating roads were also be used to minimise damage to peat.
The Viking HMP has previously been recognised by key stakeholders as being more ambitious and expansive when compared to other previously consented wind farms and as an opportunity to explore various habitat management methods.
The Viking Peatland Restoration Programme has involved the identification of 32 individual areas which require various intervention techniques to seek to restore them to an active peatland habitat. A total of 60Ha of bare peatland, within the 32 areas to varying degrees, require the redeposition of peat to address historic erosion and to bring them back to ground levels. This is termed Phase 1.
Once established, these areas will be tied in to the surrounding topography and hydrology using traditional restoration techniques known as Phase 2.
Once complete, Phase 3 will see each area monitored for 25 years (the expected lifetime of the wind farm) to evaluate the potential creation of blanket bog in the longer-term.
SPR have been involved in the Viking project for some time, assisting in the restoration of two areas on Mid Kame Ridge and have a wealth of local experience and knowledge in peatland restoration. Viking has secured their services for ongoing restoration to ensure that the best local experience and knowledge of peatland restoration is retained. Under the direction of the Habitat Management Plan Officer (Shetland Amenity Trust), SPR will assist in the completion of Phase 1 works and progress each area in to Phase 2.
Stringent measures have been put in place to help ensure that sediment created during construction does not flow into burns and lochs in and around the project site. Under the CEMP a 50m buffer zone was created around all infrastructure except stream crossings.
Pollution control will draw sediment into "drop-out" areas to prevent it reaching natural watercourses.