Update: At 14:00 8 January 2021, National Grid ESO cancelled the EMN.
National Grid ESO has once again issued an Electricity Margin Notice (EMN), its second this week and fifth this winter.
Issued just before 20:00 on 7 January 2021 by the operator, the notice was reiterated at 11:30 on 8 January although the margin had decreased.
There was an expected shortfall of 1,157MW yesterday evening for the period 16:00 to 19:00 today, which had decreased to 239MW by this morning’s update.
On Twitter, National Grid ESO explained that “tight margins on the electricity system continue owing to cold temperatures and generator availability & output levels over periods with higher demand".
“While we have enough generation to meet demand, we've issued an electricity margin notice (EMN) for Friday evening.”
Again it reiterated that an EMN is a routine signal, as it did during the EMN issued on Tuesday 5 January for between 16:00 and 19:00 on Wednesday 6 January.
Tight margins created by the cold snap that has driven temperatures 4-5 degrees below average, along with lower output from coal, nuclear and interconnectors due to the BritNed outage have led to volatile pricing all week. This saw West Burton B being called on at £3,000/MWh on Wednesday in the Balancing Mechanism.
Power prices in the N2EX auction hit £1,000.04/MWh for the period 17:00 to 18:00 on Wednesday as well, the highest hourly price seen on the auction.
EMNs are becoming increasingly common in the UK market as baseload generation from coal reduces, and it relies more on intermittent generation such as wind, increasing the challenge of balancing supply and demand.
National Grid ESO is set to review the situation again at 14:00, and provide an update.