Beauly-Denny Replacement Transmission Line

Upgrading electricity grid infrastructure is one the greatest hurdles Scotland faces to achieve the legal commitment set out in The Climate Change (Emissions Reduction Targets) (Scotland) Act 2019 to reduce Scotland's emissions of all greenhouse gases to net-zero by 2045 at the latest. Scottish and Southern Electricity Networks (SSEN), operating under licence as Scottish Hydro Electric Transmission plc for the transmission of electricity in the north of Scotland, owns and maintains the 132kV, 275kV and 400kV electricity transmission network. Its network comprises underground cables, overhead wooden poles, steel towers and electricity substations, and extends over a quarter of the UK landmass and across some of its most challenging terrain

The Beauly-Denny transmission line upgrade plays a critical role in providing security of electricity supply in Scotland, feeding up to 1.2 GW of renewable energy generated in the north to areas of high demand further south. The Scottish government placed a condition on the replacement line’s planning consent requiring SSEN to appoint an independent environmental consultant to review and report on environmental management performance.

Ramboll was appointed in 2010 to help ensure that the project unfolded in line with the very high environmental expectations set by both SSEN and the Scottish government. Working in collaboration with regulators, the transmission business and their appointed contractors helped ensure that the environmental commitments made during the consenting process were implemented during construction.

More than 800 towers were replaced with 615 higher capacity steel towers that operate at 400kV and span some of the most challenging environments in Scotland. The Corrieyairack Pass between Fort Augustus and Dalwhinnie is a short section of the route which typifies the range of technical and environmental challenges faced. The pass rises to 770m above sea level and is home to a designated Scheduled Ancient Monument, famous for its association with the Jacobite rebellion in the 18th century. Crossing this area required the management of interactions with members of the public, cultural heritage features, sensitive watercourses and upland habitats, as well as protected birds and mammals.

Ramboll provided regular audits of performance throughout the project and continued beyond completion in 2015, when we supervised the work to reinstate the areas around the towers and access tracks. Our team successfully collaborated with both SSEN and their contractors to ensure that environmental challenges were communicated quickly and efficiently, an approach that helped protect the environment and provided independent assurance to all stakeholders that project commitments were being met.

Watch the videos

SSEN has created five short films about the project, providing an oversight of the considerations and processes applied to a project of this scale and complexity, also featuring Ramboll’s project director Peter Bruce.