Making the Right Connections Kergord Substation
This prestigious appointment involves Scottish and Southern Energy’s (SSE) plans to bring high-voltage direct current (HVDC) along a 320km submarine power cable to connect the Shetland Islands to the Scottish mainland.
The Shetland HVDC Connection will provide an infrastructure connection between the GB Transmission System and the proposed wind farm promoted by the Viking Energy Partnership. The Viking Wind Farm will become one of the largest onshore wind farms in Europe with some 150 wind turbines producing a total of approximately 550 MW electricity.
Our Infrastructure & Environment team in Perth have been appointed by Balfour Beatty to be the Civils and Environmental consultant on this impressive £30m design and build scheme, known as Kergord Substation.
The project involves the design and construction of a new 132kV AC to DC converter substation with associated infrastructure at Upper Kergord Valley, Shetland. The substation will facilitate the transmission of DC electricity through underground cables to the landfall at Weisdale Voe; and from there, the subsea cable will run to the Moray mainland coast at Blackhillock Substation, near Keith.
Through an earthworks cut and fill operation, our team designed a 5 ha level platform to facilitate the new convertor substation buildings and electrical infrastructure. The designs included; earthworks; access and internal roads; sustainable foul and surface drainage; landscaping and landscape reinstatement design; and transportation. In addition, our specialists developed a fire strategy for the site as required by Building Regulations.
Design has been undertaken with a strong environmental and ecological awareness
Understanding the environmental impacts and constraints was key to this project. Our experts prepared a series of environmental reports to accompany the substation design including a Construction Environmental Management Plan, Peat Management Plan, Phase 1 Habitat Surveys, an Otter Survey Report and an Archaeological Written Scheme of Investigation.
Due to the remoteness of Kergord, the reuse of all excavated materials on the site is not only an important construction issue but also an economic issue. We conducted a detailed geotechnical assessment with sophisticated 3D modelling (AutoCAD Civils 3D) to establish the volume of topsoil, subsoil and rock arising from platform excavation. Our team further advised on how to make use of the 260,000m3 excavated material to achieve a perfect cut and fill balance.
The sewage drainage system includes a compact non-electric waste water treatment plant which requires minimal maintenance. The landscape bunds have been designed to allow for both retaining materials on site and to provide a degree of screening to the development.
Although this project involved a short design programme, ‘Part A’ has been successfully completed with initial designs for the substation platform, access road, sustainable drainage, landscaping including reinstatement and fire engineering submitted to Balfour Beatty and in turn SSE. These designs are sufficient in detail for OFGEM to approve costs. The next major milestones, ‘Part B’, will involve the detailed design and the construction phase, which is expected to commence in November 2017.
This project is a fine example of our ability to deliver multidisciplinary projects. It involved colleagues across our offices on a UK wide scale to bring in different expertise, all managed through our Perth team, working closely together to achieve the project’s milestones.
Daryl Fossett, Regional Operations Director for the Perth office and Waterman’s Kergord Substation Project Director commented; “We are delighted to have been appointed on this high profile project which builds on our established track record of successfully delivering Substation
projects for SSE. It has been a great team effort demonstrating our ability to bring expertise together from across the country as one team to produce a quality service.”