'Clear consumer benefits' from 4-GW Scotland-England subsea power cables: Ofgem

There are clear consumer benefits from proceeding with the proposed 4-GW Eastern High Voltage Direct Current Link between Scotland and England, UK energy regulator Ofgem said in a consultation document March 30.

The project, which consists of two subsea power cables, would help integrate a booming offshore wind sector off Scotland, ease the cross-border grid bottleneck from north to south and, at GBP3.40 billion ($4.47 billion), represent Britain's largest electricity transmission investment in recent history.

"We consider there is a clear consumer benefit in the Eastern HVDC projects progressing," Ofgem said. "We continue to appreciate the risk that not delivering substantial reinforcements in this area could cause a significant detriment to consumers in terms of constraint costs," it said.

A first 2-GW link being developed by National Grid Electricity Transmission and SP Energy Networks would run from Torness on the east coast of Scotland to the Hawthorn Pit Substation in Durham County, England, with 176 km of offshore cable.

A second much longer 2-GW link being developed by National Grid and SSEN Transmission would run from Peterhead in Aberdeenshire to Drax in North Yorkshire, with 440 km of subsea cable.

National Grid said it had been consulting communities near the onshore elements of the proposed route. If approved, work could start on Torness-Hawthorn Pit in 2024 and complete in 2027. Work on Peterhead-Drax could also start in 2024, to complete in 2029.

A one-year delay to these in-service dates would lead to additional constraint costs on consumers of up to GBP409 million, while a two-year delay would cost up to GBP860 million, Ofgem said.

"Given the material impact of delay to delivery, we expect NGET, SPT and SSENT to continue to progress the Eastern HVDC projects in a timely manner that ensures that the full benefits of the projects can be realised," the regulator said.

The consultation closes on May 4. A decision and policy statement would follow in June or July this year.