UK's Ofgem opens probe into Western Link subsea power cable

London — Ofgem has launched an investigation into the delivery and operation of the Western Link subsea power cable from Scotland to Wales, the UK regulator said Tuesday.

The 2.2 GW, GBP1.3 billion project was undertaken by a joint venture of National Grid Electricity Transmission and Scottish Power Transmission.

"The investigation will review the performance of National Grid Electricity Transmission and Scottish Power Transmission in delivering the cable," Ofgem said.

It would look at whether late delivery breached license conditions, and examine potential breaches in the provision of "economical, efficient and coordinated services" since the link has been in operation.

"The opening of this investigation does not imply that we have made any findings about non-compliance," Ofgem said.

The 420-km cable was originally scheduled to be fully operational by regulatory year 2016/2017, but construction and commissioning setbacks meant full operation was not achieved until October, 2018.

In July 2017, Ofgem postponed allowances to the interconnector because of manufacturing problems with the cable.

Then in September 2017 a component at the link's Scottish converter station in Hunterston failed, with fire crews attending the site. There were no casualties.

Since then the link has suffered various outages, compromising its primary role -- shipping Scottish wind power to load centers in the south of England.

Most recently the link suffered an unplanned outage January 10 this year and is expected to be out of commission until mid-February.

National Grid on January 22 said it did not know why the link tripped.

A consortium of Siemens and Prysmian built the link, running from Flintshire Bridge in Wales to Hunterston in Scotland. It is the first submarine interconnector to use a DC voltage level of 600 kV.

"It is not clear, at this stage, if the Ofgem investigation will ultimately result in a financial penalty for National Grid and Iberdrola [owner of Scottish Power] and how much of this could potentially be recovered from the sub-contractor," said investment bank Royal Bank of Canada.