Security of Supply
European energy cooperation on the agenda for Baltic TSO…
27 Oct 2025 - 3 minute read
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Winter Outlook: Complacency isn't an option
Security of Supply
8 Oct 2025 - 4
minute read
Whilst the Winter Outlook gives the best margins on the electricity system in six years, Director of Resilience and Emergency Management, Dr Deborah Petterson warns of importance of maintaining vigilance.
Three years ago, when we launched the Winter Outlook, Great Britain faced one of the most difficult winters in recent memory following the illegal invasion of Ukraine. The whole sector pulled together to meet that challenge and this year; our analysis shows that we are in a more comfortable position.
This winter, we expect to see the largest electricity margins since 2019/20, meaning we have more electricity supply than demand than any winter in the last six years. Growth in battery storage and greater availability of gas power stations, along with the commissioning of the Greenlink electricity interconnector to Ireland, have all helped grow this year’s margins to 6.1GW, almost a GW more than last year.
We continue to see relative stability in markets across Europe, giving us confidence that Great Britain will be able to rely on secure supplies from overseas when we need them.
Whilst margins have improved year on year since the impact of the COVID-19 pandemic and then the invasion of Ukraine in 2022, we understand the importance of remaining vigilant. Managing the resilience of the electricity network, and balancing supply and demand second by second, is one of NESO’s core duties.
NESO undertakes this duty to maintain a secure and resilient electricity system with the utmost seriousness. It is a complex task, balancing likely impacts of weather, reliability of technology and geopolitical factors. At the same time, we have been preparing the system to run with zero carbon so that it is ready for a clean power system by 2030 and delivering a sustainable future for everyone.
Our work has strengthened the resilience of the electricity system, whilst driving cost savings for everyday consumers. As we witness a once-in-a-generation increase in both electricity supply and network infrastructure, ensuring we retain one of the most reliable networks in the world is only becoming more important. Finding new innovative solutions to deliver resilience and manage the growing expansion of the energy sector and the data that comes with it, is critical to supporting Britain’s wider economic goals.
In the last twelve months, for example, we’ve seen Britain’s first ever grid-forming battery come online, an innovative way of replacing some of the functions of fossil fuel power plants as we move towards a cleaner energy system. These batteries can both store energy and provide stability to the system, supporting both decarbonisation and system security.
In the face of an increasingly complex energy system, we continue to enhance our control room’s ability to send complex instructions to hundreds of assets a second through our Open Balancing Platform (OBP), enabling smaller and more flexible units to participate in greater numbers. In 2023 NESO averaged about 2,300 instructions a day from the control room but today we’re averaging nearly three times that amount with over 6,700 instructions a day. We are doing the work to ensure the system can manage this increasing complexity.
As NESO we know that our work on the electricity system and our role in planning the future gas system directly impacts the everyday lives of everyone up and down the country. That’s why we take our work so seriously and plan so extensively to ensure that Great Britain’s energy systems continues to be one of the most reliable in the world.
Great Britain’s grid meets 99.9999% of demand but there is no room for complacency. NESO has a new duty to provide independent advice to government on the security and resilience of the whole energy system. We work with industry to ensure they are ready for the coming season, we have carefully planned for disruption, recognising that the supply of electricity underpins everything we take for granted in our lives. We are working with Local Resilience Forums across Great Britain to ensure that they have the information they need and understand what to do if supply is disrupted. Then should things go wrong, we have the teams to learn the lessons for the future, as in our Review of the North Hyde outage published in July.
NESO’s job is first and foremost to keep electricity flowing and prepare for future challenges, and so we make sure we are working with our industry partners, to ensure we are prepared for every eventuality. Whilst the outlook for this winter is the most positive in six years, we will continue to be vigilant and manage the electricity system in the way the public expect: with rigour, expertise and caution.
