Scottish and Southern Electricity Networks (SSEN) has switched on the £1 billion Caithness-Moray transmission link.
The 1.2GW power line from Spittal in Caithness to Blackhillock in Moray features a large subsea section stretching 113 kilometres across the Moray Firth.
The new link will allow more renewable power to be transmitted southwards from the far north of Scotland. It has already enabled turbines from the Beatrice offshore windfarm (588MW) and the Dorenell onshore windfarm (177MW) to connect to the power grid.
At a total cost of £970 million, the project was completed for less than the £1.06 billion budget set by Ofgem but nevertheless represents the largest single investment ever made by parent company SSE.
Construction work lasted for four years and included the installation of two new converter stations at either end of the high voltage direct current cable, as well as the reinforcement of two existing overhead power lines.
Dave Gardner, who led the project as SSEN's director of transmission, said: "The successful energisation and commissioning of the Caithness-Moray link, on time and within budget, is a significant achievement for SSEN and everyone involved in the project.
"Caithness-Moray has been a highly complex project, requiring very high standards of project design, development, construction and commissioning… It will support deployment of renewable energy in the north of Scotland for many years to come.
"Now an operational asset, we will closely monitor the link and associated infrastructure to ensure its continued success as an integral part of the GB transmission system."