Update (14:00): National Grid ESO has now cancelled its Electricity Margin Notice for this evening following its buffer of spare electricity being "restored to an adequate level".
National Grid ESO is currently predicting a margin shortfall of 477MW for this evening, down from the 740MW outlined last night (3 November).
Having issued a Electricity Margin Notice last night – the first one since 2016 – outlining that between the hours of 16:30 and 18:30 today (4 November) there is to be a margin shortfall of 740MW, National Grid ESO has now issued an update confirming that whilst the shortfall has dropped, the Electricity Margin Notice is still in play.
Trading points, control points and externally interconnected System Operators are now being requested to notify National Grid ESO of any additional MW capacity, with suppliers requested to advise the ESO of any additional demand control available.
A range of factors including low renewable output, the availability of generators over periods of the day and higher demand have combined to result in the shortfall, the ESO confirmed on Twitter.
However, a spokesperson for National Grid ESO was quick to assure that there is “enough generation to meet demand”, with the being shortfall in the buffer of spare capacity.
“This is a routine signal that we send to the market to indicate that we’d like a larger cushion of spare capacity and we're continuing to explore measures to further increase our buffer.”
The situation is to be reviewed again at 13:00, with National Grid ESO to publish an update following this.
The ESO also warned of tight margins in October, which was also put down to a range of factors including low wind and generator outages.
A month prior, National Grid ESO issued a Capacity Market notice, warning the margin had dropped below its 500MW threshold. However, this was swiftly cancelled an hour later, although prices did jump to over £500/MWh that night due to low wind generation.