Extreme heat across Europe is putting Britain’s electricity system under pressure, prompting the National Energy System Operator to issue an Electricity Margin Notice for this evening.
NESO said forecasts show tight margins between 6.30pm and 10.30pm on 9th July, with a projected system shortfall of 1,000MW during the evening peak. The warning is designed to bring more generation and flexible demand into the market before the system reaches that point.
A NESO spokesperson said: “Our forecasts indicate tight electricity margins during the evening’s peak period. This is due to extreme temperatures across Europe, reducing the availability of some generation.”
The notice asks power stations, interconnector operators and other market participants to identify any extra capacity they can make available. Suppliers have also been asked to report any additional demand reduction that could help ease pressure on the system.
NESO said its current contingency requirement is 550MW while 850MW of generation has been excluded from the available margin because of system constraints.
Maximum Generation Service instructions may also be used if more output is required.
The alert is not a warning that blackouts are expected and NESO stressed that electricity supplies remain secure.
Electricity Margin Notices are issued to give the market time to respond when the gap between expected supply and demand becomes tighter than usual.
The spokesperson said: “NESO has issued an Electricity Margin Notice to the market, giving participants the opportunity to make any additional generation or flexibility available during the forecast period.
“There is no risk to customer electricity supplies. An EMN is a routine operational tool NESO uses to balance the electricity system. We will continue to monitor conditions closely and take any actions necessary to maintain secure electricity supplies.”
The timing is significant because the pressure is being driven by weather across a much wider European power system, not simply conditions inside Britain. Extreme temperatures can reduce the efficiency and availability of some generating assets while also increasing electricity demand as homes, offices and businesses turn to air conditioning and cooling equipment.
High temperatures can also affect transmission infrastructure and limit output from thermal power stations that rely on cooling systems.
At the same time, tighter conditions in neighbouring countries can reduce the amount of electricity available through interconnectors.
The result is a smaller cushion between the power Britain expects to need and the generation available to meet it.
NESO will review the position again at 2pm and issue a further update.
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