As part of the wider £1.1bn Caithness Moray Shetland energy project, we constructed twin state-of-the-art High Voltage, Direct Current (HVDC) substations in Blackhillock (Moray) and Spittal (Caithness). Completed in January 2019, the duplicate facilities are key infrastructural components of a new HVDC 1200/800MW link, which connects the transmission network between Moray and Caithness. We were appointed by ABB (ASEA Brown Boveri) to undertake the associated civil, structural and building works.
The Blackhillock and Spittal Substation construction projects, with a combined value of £66m, are supporting SSE’s broader aims of transferring more power, more efficiently for the people of Scotland.
Located in remote areas, either side of the Moray Firth, the sites are over four hours apart. Nevertheless, the facilities are almost identical and include a main convertor building with a footprint of 6527m2. A three-level Control Room, a Spare Parts Building and MVS Building are further elements of each site, in addition to a Valve Cooling Area and a 3500m2 External Yard.
200 tonnes of steel were fabricated, galvanised and erected per week and approximately 620m3 of rock and 9,800m3 of earthworks were excavated and removed. Demonstrating the scale of the twin sites further, 800m3 of attenuation materials were installed and around 2200m3 of concrete were poured for the convertor substation pad, foundations, cable trenches and transformers and over 800 tonnes of structural steelwork.
"The Caithness-Moray project is at the heart of the biggest renewal of the north of Scotland’s electricity network in a generation"