HVDC in Great Britain

There are currently 4 HVDC systems in Great Britain; two to Ireland and one each to France and The Netherlands. The current links are all two-point interconnectors; they allow Great Britain to access international markets and increase the security of supply.

There are plans for a number of embedded HVDC systems in Great Britain, as an alternative to traditional AC reinforcement. The Caithness-Moray project in the North of Scotland and the Western HVDC scheme from the South of Scotland to Wales are both under construction and will be online in the near future. By the year 2030 there may be upwards of 20 HVDC schemes in operation in the UK.


SSEN are constructing the HVDC link from Spittal in Caithness to Blackhillock in Moray. There are plans to extend the Caithness-Moray (CM) system, with future links to Shetland and offshore wind farms. It has been designed, with support of Centre staff, as the first five-terminal HVDC systems in Europe. Multi-terminal systems are very complex and the control interactions of multiple systems in proximately are not fully understood.

Building an understanding of how the different controllers from the many schemes being introduced onto the network will interact is a key driver for the Centre.