ELEXON Insight: Update on Demand Reduction during COVID-19 lockdown

In this Insight, our Data & Insight Analyst, Nick Baker provides an update to the reduced electricity demand during lockdown article with the latest findings. The new graphs can be used to track electricity demand changes in Great Britain as COVID-19 restrictions start to ease.

In April 2020, ELEXON published an Insight article that highlighted measures put in place by the UK Government to control the COVID-19 outbreak, and their resulting impact on electricity demand in Great Britain. The key facts from the Insight were that demand had fallen by 17% since the lockdown measures were introduced, and that generally weekday demand has fallen to levels typically seen at weekends.

The graphs compare changes in demand following Government advice that people should work from home (16 March) and the subsequent lockdown decision (23 March) with demand patterns over similar periods, in previous years. The graphs provide Initial Demand Out-turn data up to 23 June and Grid Supply Point data up to 31 May. The data will be refreshed on a monthly basis while restrictions continue, as more data becomes available. Our latest data shows that:

  • average demand across GB in MW (Initial Demand Out-turn) was 19% lower in April and May compared with the same period last year
  • demand in English and Welsh regions (based on Grid Supply Point Group Take) has fallen the most in South West England and least in North West England compared with April and May 2019
  • for the first time the South West (GSP Group _L) has been a net exporter to the Transmission Network during some afternoon Settlement Periods while COVID-19 restrictions have been in place.

Initial Demand Out-turn

The Initial National Demand Out-Turn (INDO) is published by ELEXON on the Balancing Mechanism Reporting Service (BMRS) every half hour and shows average demand in megawatts across GB for each Settlement Period.

The graph below shows daily average INDO since January 2017 up to 23 June 2020. The period of COVID-19 restrictions has been highlighted along with the corresponding time period in each year to aid comparison between years.

You can adjust the date range shown in this graph by using the Settlement Date slider underneath the graph.

Whilst the COVID-19 restrictions continue, and demand reduces, as we head from spring into summer, the daily average INDO dropped below 20,000MW at the end of May 2020 and also in June. The graph highlights that this is the lowest that the daily average INDO has been in the last three and a half years. The minimum daily average demand for May of 19,143MW represented a 10.7% reduction compared with the lowest daily average demand in May 2019.

Since 2017, the lowest daily average demand prior to the COVID-19 restrictions was 20,335MW on 18 August 2019.

Grid Supply Point Group Take

Grid Supply Point (GSP) Group Take is the net energy measured coming from or going into a particular Local Distribution System (i.e. a GSP Group) in a Settlement Period. There are 14 GSP Groups across Great Britain. Within a GSP Group, demand comes from Non Half Hourly (NHH) sites, which are generally households and smaller businesses, and Half Hourly (HH) sites, typically larger businesses or industrial sites.

The graphs for GSP Group Take below depict a positive GSP Group Take as where electricity is being imported from the Transmission Network into a region. A negative GSP Group Take, would represent where the GSP Group is exporting (providing electricity to the Transmission Network).

Monthly Net GSP Group Take by region

In the graph above the net GSP Group Take (sum of positive and negative GSP Group Take) is displayed in comparison to the previous three years for 1 March to 31 May. You can select the month and region to view a comparison of the impacts of the COVID-19 restrictions for a specific region compared to the same month in a previous year.

In England, in April and May, the South West (GSP Group _L) had the largest percentage reduction in monthly net GSP Group Take (in part due to being a net exporting region for the first time). This is compared to 2019, with April and May decreasing by 24.2% and 26.2% respectively.

The North West (GSP Group _G) saw the smallest demand reduction with 16.6% and 16.7% less net GSP Group Take for April and May in 2020 compared to the corresponding months in 2019.

Demand across a day

The day of the week and the region have an impact on the average GSP Group Take, as typically each day and each region have different levels and patterns of demand. There are also a number of elements that will have an impact on demand, not least weather, which varies between regions and across GB. The location of industrial load also has a bearing on demand across the regions.

Comparisons of weekdays and weekends for no restrictions and lockdown

The graph on GSP Group Take below compares demand on weekdays and weekends during the COVID-19 restrictions to the same period in previous years (17 March to 31 May).

Comparison of restriction and day type with previous years

Weekend demand has been shown as dashed lines in the graph. This highlights a continuation of the trend we identified in my last Insight, where the shape and volume of demand on a weekday, after COVID-19 restrictions were put in place across all GSP Groups, is now more comparable to a weekend. This pattern is particularly noticeable in April and May across all GSP Groups.

As an example, in April and May in the Eastern region (GSP Group _A), an average weekday in 2018 and 2019 would have seen an increase in GSP Group Take of 491MWh between 5am – 8:30am (Settlement Periods 12 and 17). For the same time period at a weekend, the pick-up in demand was 251MWh. However during a weekday in the COVID-19 lockdown in April and May 2020, this pick-up has been on average 219MWh, therefore more comparable with a weekend.

The March data includes Settlement Dates (and the corresponding dates in previous years) following the Government’s announcement on 16 March 2020 that people should work from home if they are able to.

Temperature and demand relationship

In Great Britain the general relationship between temperature and energy demand is that colder weather will result in higher electricity demand, and warmer weather lower electricity demand.

The scatter graphs below plots the relationship between noon temperature within each GSP Group (used by ELEXON as part of the NHH Load Profile process), and GSP Group Take. The first graph shows the impact of restrictions on Weekday GSP Group Take, the second shows the impact of restrictions on the Weekend GSP Group Take. 

Impact of restrictions on Weekday GSP Group Take in a Settlement Period

Impact of restrictions on Weekend GSP Group Take is a Settlement Period

You can select the region (GSP Group) and Settlement Period (a half-hour time period within the day, typically 48 in total) to investigate the impact of the COVID-19 restrictions further using the orange drop down boxes. 

The data covers the COVID-19 restriction period, 17 March to the 31 May, in 2018 to 2020 and excludes Bank Holidays.

The data shows the general relationship that GSP Group Take falls as temperature increases. Lower than normal GSP Group Takes have been seen during the COVID-19 restriction period for temperatures similar to those in previous years.

The impact of the COVID-19 restrictions can clearly be seen on a weekday morning, for example in half hourly demand during rush hour, in Settlement Period 18 (08:30 to 09:00), in London (GSP Group _C). Due to  people working from home and businesses being closed because of the COVID-19 restrictions, the London GSP Group Take during this half hour is 22.5% less than it was for a similar weekday, on dates with a similar temperature of 15oC (+/- 0.5 oC), in the last two years.

The demand reduction in the South West (GSP Group _L) has meant that for the first time on some afternoons, between 12:00 and 15:00 (Settlement Periods 25 to 30), the region is exporting energy to the Transmission Network. This has happened on weekdays and weekends when the COVID-19 restrictions were in place, but typically when temperatures are higher and demand would ordinarily be lower. As explained earlier exporting energy to the Transmission Network shows as negative GSP Group Take. The South West has a large amount of installed solar generation capacity, and together with higher temperatures, corresponding high-levels of sunshine, and the reduced demand due to the COVID-19 restrictions, this has enabled the GSP Group to be a net exporter for the first time.

Data resources

Find out more background information and data sources mentioned in this article.

Balancing Mechanism Reporting Service

ELEXON makes a significant amount of data available for free under an open data licence through the Balancing Mechanism Reporting Service (BMRS). The BMRS is the best source for tracking the electricity wholesale market in near real time, including the generation mix and demand. 

Also, Initial Demand Out-turn data is publicly available on BMRS.

GSP Group Take

GSP Group Take data is available for BSC Parties via the CDCA-I029 ‘Aggregated GSP Group Take Volumes’ data flow. Non-BSC Parties can access the same data flow through the P114 licence data flows set.


The ELEXON Data section provides an overview of the content on the BMRS, the ELEXON Portal and of data flows available to BSC Parties and the public.


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