This MSIP application presents the needs case to develop and install a Dynamic Line Rating (DLR) system on the existing 275kV Overhead Line (OHL) circuits from Beauly – Loch Buidhe and Loch Buidhe – Dounreay.

A significant quantity of renewable generation is currently contracted to connect in the Caithness area of SSEN Transmission’s network, north of Beauly substation, with the volume of renewable generation continuing to grow as we progress towards the UK and Scottish Government’s net zero targets by 2050 and 2045 respectively.   Due to the volumes of renewable generation looking to connect, it is expected that there will be significant network constraints in the area from 2024. 

Whilst the long term solution to addressing those constraints is the development of strategic reinforcements in new and upgraded electricity network infrastructure, in the short term, the deployment of DLR can help manage the system by alleviating constraints north of Beauly to enable additional transport of renewable electricity.

The DLR system will consist of meteorological stations placed at critical locations on the circuits.  These will relay real time environmental conditions to a control system which will calculate the real time temperature of the conductor and in turn the Overhead Line (OHL) rating, maximising the capacity of the existing OHL to securely transport more renewable electricity. 

Deploying DLR will aid in managing the system north of Beauly and will see GB consumers benefit from reduced network constraint costs. Following the completion of the project the technical and operational learnings related to DLR can be introduced to other areas of the network, where economic and efficient to do so, to deliver further benefits to the GB system and GB consumer.

The works are planned to be completed by 2024 when constraints are expected to occur.

Any confidential or commercially sensitive information has been redacted from the document.