Ofgem has opened an investigation into National Grid and Scottish Power’s transmission arms over repeated outages and late delivery of the Western high-voltage (HVDC) subsea cable.
The £1.3billion Western HVDC connector links Highland wind farms via Hunterston to North Wales. On 10 January 2020, the 239-mile subsea stretch suffered its third complete trip out in three years. A subsea fault in Liverpool Bay is suspected.
Planned to open in 2015 at 2.2 GW capacity, the link arrived two years late in December 2017, and then only at 900 MW. Cable problems at manufacturer Prysmian were blamed.
Scottish Power and National Grid took over operations in 2018, and full power was reached only in October that year. Further outages included five weeks in spring 2019.
The regulator’s probe will focus on performance of both operators. At issue is whether the project’s late delivery breached Special Licence Condition 6I, which specified the project’s delivery date. Ofgem will also consider compliance with standard licence condition D, on provision of transmission services, and section 9(2) of the Electricity Act 1989, covering provision of economical, efficient and co-ordinated services.