UK electricity balancing costs up 15.4% in February on Western Link outage

London — UK electricity system balancing costs rose 15.4% month on month in February to GBP167.2 million ($232.3 million) as the Scottish wind constraints rocketed, data from National Grid ESO showed March 12.

Constraint costs alone rose from GBP41.1 million in January to GBP101.1 million in February.

"Constraint costs rose significantly following the loss of the Western Link HVDC mid-month, resulting in a larger number of actions required to manage the Cheviot congestion," the system operator said.

The 2.25 GW Western Link subsea cable runs from Hunterston in Scotland to Flintshire Bridge in Wales. It helps transit Scottish wind to load centers in the south, sidestepping transmission bottlenecks on the Scottish border with England.

The 420-km cable tripped on Feb. 15. It was due to return to service March 11, according to a National Grid briefing March 10.

The volume of accepted bids in Scotland in the Balancing Mechanism reached 430 GWh in February, up from 46 GWh in January when the link was fully available, according to S&P Global Platts Analytics.

Between Jan. 1 and Feb. 15 National Grid reported daily average constraint costs of GBP0.5 million/day. This rose to GBP6.1 million/day from Feb. 16 to Feb. 25.

Balancing Services Use of System (BSUoS) charges in February averaged GBP4.92/MWh, up from GBP3.66/MWh in January.

National Grid ESO forecast this to drop to GBP3.88/MWh in March, and to average GBP3.89/MWh over the next 12 months.