BSC Insights: Great Britain’s first coal-free Christmas occurs in 2020

Mehdi Jafari investigates the electricity generation and demand over the Christmas period 2020.

This period covers Christmas Eve to Boxing Day 2020. Our analysis shows that:

  • on Christmas Day 2020, no coal was used for electricity generation. So, for the first time ever, GB had a coal-free Christmas
  • on Christmas Day 2020, demand at lunchtime was the highest since 2016
  • Christmas Day was the coldest Christmas since 2012
  • Christmas Day was also the last coal-free day of 2020

The highs and lows of Christmas 2020

No coal in our generation; no coal in our stockings

Christmas Day 2020 was different for most of us. The UK had a COVID-19 Christmas, which only allowed family gatherings in areas that were classed as tier 1-3. This left many people cooking an unexpected Christmas dinner and partaking in festivities virtually. Christmas Day 2020 was also ground breaking for electricity generation. It was the first Christmas Day ever to not burn any coal, despite a 3.87% generation increase compared to 2019. However, we do hope that Christmas was truly coal-free and coal was not diverted into stockings to provide ‘gifts’ for naughty children! 

Average of Initial Demand Out-turn 

Christmas Day 2020 was the coldest Christmas Day since 2012. The daily average temperature was 3.6oC, which was 3.1 degrees colder than Christmas Day 2019. The graph below shows the Initial Demand Out-turn, average demand in megawatts (MW) across GB for each Settlement Period (SP), for Christmas Eve, Christmas Day, and Boxing Day over the last five years.

While the average demand per SP in 2020 was 6.3% lower than 2019, Christmas Day 2020 experienced the highest Christmas Day demand per a SP since 2016, with 36,492MW in SP27 (13:00-13:30). This could be, in part, due to low temperature. It could also be, in part, due to international and domestic travel bans, which caused more people to stay at home due to COVID-19 restrictions. While the average demand was 4.5% higher on Christmas Day 2020 than 2019, the peak demand on Christmas Day 2020 was 10% greater than that on Christmas Day 2019.

Other than Christmas Day 2016 when the highest demand was at SP26 (12:30-13:00), for the next four years Christmas Day demand peaked half hour later at SP27.

Demand on Christmas Day

As the graph suggests, there is a different demand pattern on Christmas Day. While Christmas Day is the only day with the highest demand at SP27, demand on all other December days, regardless of whether it was a weekday or a holiday, peaked at either SP35 (17:00-17:30) or SP36 (17:30-18:00). This is potentially because almost all over the country, families gather for Christmas lunch, causing a demand peak at around 13:00 to 13:30. The energy consumed in GB over Christmas Day 2020 lunchtime was 27% higher than the average Christmas Day, and 12% above December 2020 average per SP.

More on Initial Demand Out-turn

Generation by fuel type

The pie chart below shows how the generation mix has changed over the Christmas period since 2016. Coal contributed 13.3GWh of generation to Christmas Day 2019, which was 1.94% of total generation. In 2020, wind generation replaced this 1.94%. On Christmas Day 2020, wind electricity generation was 189.3GWh, which is more than double that of Christmas Day 2019 at 74.7 GWh.

This Christmas being coal-free also broke the previous ‘low coal Christmas’ record set in 2017 when 10.8 GWh energy came from coal, 1.63% of total generation.

Coal-free and coal-dependent days

The first coal-free day in 2020 was 8 March and the last one was Christmas Day. The coal-free Christmas Day was sandwiched with two coal-dependent days, Christmas Eve and Boxing Day with respectively 3.88 GWh and 4.75 GWh (0.53% and 0.74% of energy mix). This was 70% lower than 2019.

Wind generation increased by 50% on Boxing Day 2020 compared to Christmas Day 2020. This resulted in negative System Prices for four hours from 04:30 to 08:30.

The decline of coal

During 2020 as a whole, coal generation fell from 9.86% in 2016 to 1.75% in 2020. This is the lowest share of coal ever. Wind and biomass have filled in the gaps left by coal; generating one third of electricity in 2020 compared to 7.46% in 2016. Monthly generation from biomass peaked in December 2019 at over 2TWh. May 2020 was the first coal-free month, and February 2020 benefited from the highest wind generation ever with almost 7TWh making up 30% of the energy mix.

Data used for article

The data used is publicly accessible through the Balancing Mechanism Reporting Service (BMRS).


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