NESO cancels Monday morning electricity margin notice as low wind tightens supply
The system operator asked the market for extra generation on Sunday evening, when its forecast showed a 1,388MW shortfall in spare capacity for Monday morning. By 9.11am the notice had been withdrawn.
By Daily Oracles News Team2 min read
The National Energy System Operator (NESO) cancelled an electricity margin notice at 9.11am on Monday, having spent the night asking power stations and interconnector operators for extra capacity to cover a gap left by very low wind output.
No other grid warnings were in force once it was withdrawn.
The shortfall
The first notice went out on Sunday evening. It covered 6am to 11am on Monday and put the system margin shortfall, the gap between the spare capacity NESO wanted and what was available, at 1,388MW. It also set a contingency requirement of 808MW, the extra generation the operator wanted held back in case it was needed.
A review at 4am produced a revised notice. The window narrowed to 8am to 11am, the shortfall fell to 500MW and the contingency requirement dropped to zero. By 8.24am the shortfall was down to 200MW, and the notice was cancelled 47 minutes later.
Each version told generators that NESO might use its Maximum Generation Service, which allows it to ask plants to run above their normal output, and asked suppliers to say whether they had any extra demand control available.
Wind and gas
The notice came during a spell of low wind across Europe that began at the end of last week. Elexon's figures for 7.30am show wind farms producing 397MW while combined-cycle gas plants were generating 23,707MW.
Britain was still exporting power to the continent at the time. Of the interconnectors, only the North Sea Link to Norway was bringing electricity in, at 1,400MW.
Margin notices
NESO uses margin notices to signal to the market that it wants a bigger cushion between demand and available supply in the short term. The notices state that they do not mean blackouts are imminent or that there is too little generation to meet current demand, and the operator described Monday's notice as routine and precautionary.
Such notices have traditionally been issued on cold winter evenings, when demand peaks. NESO has issued several since the summer, when heatwaves pushed demand up.
