Winter Review and Consultation

Today our Winter Review and Consultation has been published. This is an annual document which compares what we forecast in our Winter Outlook 2020/21 publication with what actually happened. It also provides an opportunity for stakeholders to share their views on the winter ahead and how we can approach any opportunities and challenges.  

Read the Winter Review and Consultation 

As anticipated in our Winter Outlook, this winter saw a little more tightness in the system than in recent years – though well within the security of supply standard. Our control room experts managed some occasionally challenging conditions to keep our electricity flowing and the country’s lights on. 

What is the Winter Outlook and why do we need it? 

Every year, the ESO works with industry experts to present a view of supply and demand for the winter ahead in its Winter Outlook. The information helps us deliver a reliable and secure supply of electricity and helps the industry plan for winter.  

What does the ESO’s Winter Review tell us about last year? 

Although temperatures were relatively average, winter 2020/21 was a season of variable weather. We saw wind varying between high-level periods and unusually low wind, as well as some unseasonably cold spells. This winter also included numerous transitions in and out of national and regional COVID-19 lockdowns, presenting an uncertain impact on national demand patterns.  

How did COVID-19 impact Winter Operations? 

Ahead of winter, there was still uncertainty around how COVID-19 restrictions would impact demand levels. Lockdowns changed the way that people consumed energy. Some shops, manufacturers and other high-energy users were closed, whilst domestic use increased as more people were at home.   

There were also a high number of planned outages over the winter period following delays to works during the COVID lockdowns over the summer and autumn. This made the winter a challenging time to balance the grid.   

How did we balance the grid in more challenging circumstances? 

Winter 2020/21 had tighter margins than the previous winter and this was reflected in the issuing of six Electricity Margin Notices (EMNs) and two Capacity Market Notices (CMNs) between November 2020 and January 2021. ​While EMNs and CMNs reflect the normal working processes of the market, these were the first EMNs issued since 2016.  

Did you know? Electricity Margin Notices (EMNs) and Capacity Margin Notices (CMNs) are industry tools we use to manage the national electricity network. Notices are issued to signal to the market that our operating margin (our safety buffer) is lower than we’d like and we want to increase it.  It doesn’t mean electricity supply is at risk and our control room has considerable experience dealing with reduced operating margins, with the tools and expertise to manage it. To find out more visit our website.  

We’re seeking industry input for this year’s Winter Outlook 

The lessons learnt from the previous winter sometimes mean that we change our Winter Outlook approach and analysis.  

We‘d like your views on how we manage any system challenges which may occur over the upcoming winter period - your insight helps us build a comprehensive picture of the challenges and opportunities we may face in the forthcoming winter. ​Head to the consultation section of our report to find out how you can provide feedback. 

Head to the consultation section of our report to find out how you can provide feedback.