UK's National Grid issues fresh Electricity Margin Notice warning for Nov. 5

London — UK electricity system operator National Grid issued another Electricity Margin Notice in the evening of Nov. 4, the second in as many days, as a high-pressure weather system suppressed wind generation and increased power demand.

Electricity margin notices are used to send a signal to the market of looming tightness in supply. They highlight that, in the short term, National Grid needs a greater safety cushion between power demand and available supply.

"There are continued tight margins on the electricity system owing to factors including the weather, demand and the availability of generators," National Grid said in a tweet.

The notice indicated that between 1630 and 1830 GMT Nov. 5 there was a 466 MW shortfall in projected margin.

As such, a Maximum Generation Service may be instructed, the notice said.

"Maxgen" allows generators to offer capacity outside an asset's normal operating range in emergency circumstances.

Neighboring interconnected system operators in France, Belgium, the Netherlands and Ireland were requested to notify National Grid of any additional MW capacity.

The notice "does not signal that blackouts are imminent or that there is not enough generation to meet current demand," the system operator stated.

National Grid had issued a similar notice in the evening of Nov. 3, later cancelling it at 1312 GMT Nov. 4.

Tight generation margins in the UK reflected a drop in temperatures, low forecast wind generation and a relative lack of flexible supply, Glenn Rickson of S&P Global Platts Analytics said Nov. 4.

Outages at Langage and Drax 4 compounded the long-term unavailability of three gas-fired power stations owned by Calon Energy, after the company was put into administration in August.

"The EMN marks the first real period of tightness for the GB market after the clock change period," Rickson said.

"But with the new England-wide lockdown due to kick in from Thursday [Nov. 5], its impact on the crucial early evening "lighting up" period remains highly uncertain – and a greater number of people being at home in the 1630-1830 window could put further pressure on National Grid's ability to balance the market over this time window for the forthcoming month [and potentially beyond]," he said.