Post: ESO issues first Electricity Margin Notice of 2023 and calls contingency coal units 

ESO issues first Electricity Margin Notice of 2023 and calls contingency coal units 

National Grid ESO has called on four of its contingency coal units to warm, as well as issuing an electricity margin notice (EMN), as capacity margins for the evening peak on 7 March. 

On 6 March at 22:30 National Grid ESO issued an Electricity Margin Notice (EMN) for the period from 16:30-20:30 on 7 March. The system operator noted a margin shortfall of 980MW and a contingency requirement is 700MW. Cold weather combined with continued strikes at EDF in France and low wind forecasts (expected to drop to 1.2GW by the end of the day) led to a negative de-rated margin.  

“An electricity margin notice (EMN) has been issued to the market. This is a routine tool that we use most winters, and means we are asking generators to make available any additional generation capacity they may have. The EMN does not mean electricity supply is at risk,” said the operator in a statement. 

EMNs are a tool the control room can use to signal to the market that they are forecasting less spare capacity than they would prefer and that they would like the market to provide it. There hasn’t been an EMN this winter, but there have been two Capacity Market Notices issued, one on 22 November and one on 28 November, both of which were cancelled shortly after. 

In addition, four coal contingency units were warmed, providing National Grid ESO with up to 2090MW of additional capacity. “The ESO has issued a notification that we will warm four of our five winter contingency coal units for potential use on Tuesday 7 March,” said National Grid ESO in a statement. Initially, the operator called on one of the 400MW West Burton coal units to warm a little after 15:30 yesterday (6 March).  

In the early hours of this morning, it issued notices through the Balancing Mechanism (BM) calling on the second West Burton unit as well as both of the Drax coal units to warm. This marks the fifth time that the units have been warmed this winter, with the instruction issued by the operator on 7 February, 26 January,  23 January and 12 December.  

At 13:51 on 7 March West Burton Unit 1 was activated, the first time the contingency coal units have been used this winter.