Skip to content

the Blackout report

What happens when there is no power?

four electricity pylons in snowy field with sunny blue sky

National Grid’s Winter Outlook 2021 Predicts Tight Electricity Margins

Posted on October 7, 2021October 7, 2021 By Chris Owens No Comments on National Grid’s Winter Outlook 2021 Predicts Tight Electricity Margins
Power Insights, Power News

Britain will have enough electricity to avoid disruption over the coming months, but National Grid ESO’s Winter Outlook 2021 warns supplies will be tighter than last year.

The system operator’s forecast comes in the midst of record-high gas prices. In addition, an energy crunch has seen nine suppliers go out of business in the last few weeks.

Winter Outlook 2021 suggests the de-rated margin – the amount of excess capacity above peak demand – for the coming months is 3.9 GW, which equates to 6.6% of overall capacity.  

This is down from 4.8 GW (8.3%) last winter and is the lowest margin since 2016-17. It is also tighter than the 7.3% margin predicted in a provisional analysis National Grid ESO published in July.

One reason for this drop is the fire in September that damaged the IFA1 interconnector, which will cut capacity from the link by roughly 1 GW until next March at the earliest.

The worst-case scenario outlined in Winter Outlook 2021, which would include multiple power plant outages, low winds, and bitterly cold temperatures, could even see the margin plunge to just 2.5 GW (4.2%).

Despite the forecast of tightness in supplies, National Grid ESO offered reassurance that there was no increase in the risk of blackouts.

Its forecast Loss of Load Expectation (LOLE) is just 0.3 hours. This is the metric National Grid ESO uses to measure the security of supply. The figure is well within the system operator’s reliability standard of three hours.

🔹 we may take more action in the market than in previous years to secure supply – including issuing electricity margin and capacity market notices.

For more insight into our view of winter supply & demand for 2021/22 read our full report 👉 https://t.co/Kt8hlh2AVu [2/2]

— National Grid ESO (@NationalGridESO) October 7, 2021

Mitigating Tighter Margins

Just like it did last winter, the system operator expects it may have to issue Electricity Margin Notices (EMNs) to help meet demand.

An EMN is a call for the market (i.e. energy suppliers) to increase the amount of electricity they make available to increase capacity on the grid. They are issued when supply margins are looking tight ahead of real-time. They don’t necessarily indicate that demand will not be met.

For example, last winter saw six EMNs issued between November 2020 and February 2021, the first ones since 2016. But each one was later cancelled after the market reacted with increased output.

Winter Outlook 2021 predicts it will issue a similar number of EMNs for the coming months.

“The Winter Outlook confirms that we expect to have sufficient capacity and the tools needed to meet demand this winter.

“Margins are well within the reliability standard and therefore we are confident that there will be enough capacity available to keep Britain’s lights on.”

– Fintan Slye, Executive Director of National Grid ESO

Read the Winter Outlook 2021 in full here. And see what the Blackout report had to say about the Winter 2019 and Winter 2020 publications.

Tags: coronavirus Covid-19 electricity exports electricity imports Electricity Margin Notice electricity network Fintan Slye gas grid frequency Loss Of Load Expectation National Grid National Grid ESO National Grid Winter Outlook power generation

Post navigation

❮ Previous Post: Biggest Blackouts In History: South Australia 2016
Next Post: Lebanon Hit By Nationwide Blackout ❯

You may also like

greyscale overview of kandy, sri lanka
Power News
Sri Lanka Plunged Into Darkness By Nationwide Power Cut
August 18, 2020
Power News
Rolling Blackouts Across Taiwan Following Power Plant Failure
May 13, 2021
electricity pylon in winter with ice on the pylon and a bright blue background
Power News
“Slow And Patchy” Progress Integrating Flexibility Into Grid, Report Warns
March 3, 2020
Power Insights
National Grid Publishes Winter Outlook 2020 Amid COVID-19 & EU Uncertainty
October 15, 2020

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Download the blackout report

Latest Comments

  1. 10 Surprising Truths About the Power Grid You Were Never Told - Indian Opinion on Biggest Blackouts In History: South Australia 2016May 28, 2025

    […] Grid inertia—the natural resistance of heavy spinning turbines to speed changes—is critical for maintaining frequency stability. Traditional coal and…

  2. Patrick Mccormick on What Is The Low Frequency Demand Disconnection (LFDD) Scheme?May 22, 2025

    Your writing is so genuine and heartfelt It's refreshing to read a blog that is not trying to sell something…

  3. Tiago on Is The UK Prepared For A Widescale Power Cut? Rating The RiskMay 2, 2025

    Towards what happened in Portugal and Spain last Monday, I’m reading every line you wrote about it. Apparently we suffered…

  4. ‘Unforced Error’: Energy Experts Say ‘Rush To Renewables’ Helped Trip The Switch On Spain’s Grid Crash – Victory MAGA on Biggest Blackouts In History: Italy 2003May 1, 2025

    […] the most significant power outages in European history and is the largest in the region since a 2003 blackout…

  5. ‘Unforced Error’: Energy Experts Say ‘Rush To Renewables’ Helped Trip The Switch On Spain’s Grid Crash – Feeds by OffthePress on Biggest Blackouts In History: Italy 2003May 1, 2025

    […] the most significant power outages in European history and is the largest in the region since a 2003 blackout…

the Blackout report

Get Your Free Report!

Download Now

Tags

9 August 2019 Blackout battery storage Biggest Blackouts in History coronavirus Covid-19 cyberattack cybersecurity distributed energy Distribution Network Operator DNO E3C electricity network electric vehicles Energy Emergencies Executive Committee energy storage Fintan Slye frequency response grid frequency hacking hurricane inertia LFDD lightning load shedding Low Frequency Demand Disconnection malware National Grid National Grid ESO net zero offshore wind Ofgem onshore wind power generation ransomware renewable energy severe weather smart grid solar power storm substation transmission line Ukraine wind wind farm zero carbon

Copyright © 2025 the Blackout report.

Theme: Oceanly News Dark by ScriptsTown