NESO system warning
Electricity Margin Notice, 8 November 2026
Issued 19:17 · 8 November 2026
Status
No cancellation recorded
Stated shortfall
1,388 MW
Notices published
2
What this means
An Electricity Margin Notice is NESO asking the market for more generation. It is a routine signal that the forecast spare capacity for a given period is thinner than the operator wants, not a warning that the lights are about to go out — margin notices are issued, met by the market, and cancelled.
For how margin notices work and what actually triggers them, see electricity margin notices, explained.
The notices, as published
8 November 2026 19:17
From : Power System Manager – NESO Electricity Control Centre
ELECTRICITY MARGIN NOTICE
An ELECTRICITY MARGIN NOTICE has been issued by the National Energy System Operator to encourage market actions to increase System Margins.
For the period:
from 06:00 hrs to 11:00 hrs on Monday 09/11/2026
There is a reduced system margin. System margin shortfall 1388 MW
The current contingency requirement is 808 MW.
0 MW of generation is excluded from the available system margin due to system constraints.
Maximum Generation Service may be instructed.
Trading Points, Control Points and Externally interconnected System Operators are requested to notify National Energy System Operator of any additional MW capacity.
Suppliers please advise National Energy System Operator of any additional Demand Control available.
The situation will be reviewed again by National Energy System Operator at 04:00 hours and an update issued.
This Notification of Issue of a GB Transmission System Warning - ELECTRICITY MARGIN NOTICE Issued at 19:15 hrs on 08/11/2026
Issued by Power System Manager NESO Electricity Control Centre
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Information Note:-
As the System Operator, National Energy System Operator are responsible for balancing the electricity system in the final hours before real-time. We have a number of routine tools we can use to help us do this, this toolkit includes ELECTRICITY MARGIN NOTICES. An ELECTRICITY MARGIN NOTICE is used to send a signal to the electricity market. It highlights that, in the short-term, we would like a greater safety cushion (margin) between power demand and available supply. It does not signal that blackouts are imminent or that there is not enough generation to meet current demand.9 November 2026 04:20
From : Power System Manager – NESO Electricity Control Centre
ELECTRICITY MARGIN NOTICE
An ELECTRICITY MARGIN NOTICE has been issued by the National Energy System Operator to encourage market actions to increase System Margins.
For the period:
from 08:00 hrs to 11:00 hrs on Monday 09/11/2026
There is a reduced system margin. System margin shortfall 500 MW
The current contingency requirement is 0 MW.
0 MW of generation is excluded from the available system margin due to system constraints.
Maximum Generation Service may be instructed.
Trading Points, Control Points and Externally interconnected System Operators are requested to notify National Energy System Operator of any additional MW capacity.
Suppliers please advise National Energy System Operator of any additional Demand Control available.
The situation will be reviewed again by National Energy System Operator at 07:30 hours and an update issued.
This Notification of Issue of a GB Transmission System Warning - ELECTRICITY MARGIN NOTICE Issued at 04:15 hrs on 09/11/2026
Issued by Power System Manager NESO Electricity Control Centre
**************
Information Note:-
As the System Operator, National Energy System Operator are responsible for balancing the electricity system in the final hours before real-time. We have a number of routine tools we can use to help us do this, this toolkit includes ELECTRICITY MARGIN NOTICES. An ELECTRICITY MARGIN NOTICE is used to send a signal to the electricity market. It highlights that, in the short-term, we would like a greater safety cushion (margin) between power demand and available supply. It does not signal that blackouts are imminent or that there is not enough generation to meet current demand.Notice text is reproduced verbatim from NESO via the Elexon BMRS SYSWARN dataset. GridHz adds the grouping, timings and context above.