Dunmaglass Wind Farm, Inverness, Scotland

Dunmaglasses wind farm

SSE's Dunmaglass wind farm, situated 25km south of the city of Inverness, Scotland, is the highest wind farm ever to be constructed by the Scottish energy company, at 700m above sea level.

The Scottish Government approved the 94.05MW project in December 2010. SSE acquired the 33-turbine project from Renewable Energy Systems Group (RES) in May 2013.

Construction of the wind farm was initiated in 2014 and the turbines were delivered in May 2016. The majority of the work has been completed as of August 2016, while full-scale operations are scheduled to begin in 2017.

The estimated total investment for the project is £200m ($267.7m).

Dunmaglass wind farm make-up

GE was contracted to supply its 2.85-100 wind turbines with a 70m-high tower for the Dunmaglass project. The company custom-designed and developed the turbines for project to meet the strict constraints imposed by the local authorities that required a maximum blade tip height of 120m. Each turbine is up to 120m-high to the tip of the blade, whereas the hub height is 80m.

Other components of the project include two 80m-high anemometry masts, 12.5km upgraded roads, 20km of new access roads, a new substation, on-site borrow pits, and a construction camp.

Power transmission system for the Dunmaglass wind farm

A new substation known as Farigaig substation has been built outside the farm near Torness, Inverness. The 275/132kV substation comprises a control building, two super-grid transformers and two steel overhead line towers.

The substation will connect the wind farm to the national grid for distribution of the generated power. Scottish Hydro Electric Transmission has established a new electrical connection using both overhead and underground cables to establish the connection.

A section of the overhead trident wood poles from the Farigaig substation will be connected to a new terminal pole located 1.5km north of the junction. An underground cable section will be built between the new terminal pole and the Farigaig substation to avoid unnecessary overhead lines near the substation.

Contractors involved

"The project will also help in reducing green gas emissions by displacing between 80,000t and 180,000t of carbon-dioxide emissions a year."

RJ McLeod, a civil contractor based in Highland, was awarded two civil work contracts including a £5.5m ($8.85m) enabling works contract and a £16m ($25.74m) civil engineering works contract.

The scope of the enabling works included construction of two temporary timber deck bridges, a main works site compound, a new platform for the on-site substation, upgradation of the existing track, and development of the on-site rock borrow pit.

The main civil works contract included the construction of bases for the 33 turbine and crane hard standings and related cabling and drainage works.

Ground engineering and sustainable solutions provider, Aarsleff, was responsible for the installation of 140 piles for four wind turbines.

Dunmaglass wind project benefits

The wind project will help the Scottish government's goal of generating sufficient renewable energy to meet 100% of gross annual consumption by 2020. It will produce clean, carbon-free electricity sufficient to cater the needs of more than 40,000 households a year.

The project will also help in reducing green gas emissions by displacing between 80,000t and 180,000t of carbon-dioxide emissions a year. In addition, it is estimated to create more than 57,000 man work days locally and regionally.

Over its lifespan, the wind farm will contribute £4m ($5.35m) towards a community fund, which will be spent on local community projects.