Update on the data on coal-free period of 18 days

Britain experienced it’s longest ever coal-free period of 18 days and 6 hours from 17 May to 4 June 2019. ELEXON’s Balancing Mechanism Reporting Service (BMRS) is the key data source you can use to see how electricity was been generated over this period. You can also receive free, near real time updates on key trends in the electricity sector.

Why use ELEXON’s BMRS data?

Fuel mix graph on BMRSThe BMRS is the best source for data to keep track of generation by fuel type. It also provides other information including on electricity demand and imbalance prices.

Data on the BMRS is free to view and free for organisations to use if they apply for an open online licence. You will have seen our data reproduced in newspapers and by other websites, but nothing is better than going to the source data.

This licence is available even if you are not signed up to the Balancing and Settlement Code.

However, our near real-time data updates every 30 minutes and also includes historic information.

Data is also available on imbalances prices. Imbalance prices are charged to generators or suppliers to settle differences between contracted generation, or consumption, and the amount that was actually generated, or consumed.

How to access the data

All BMRS data is available through our dedicated portal and users can sign up to receive rapid alerts through Application Programming Interfaces (API) and ‘data push’ services.

Example of our data and its insights

The BMRS ‘generation by fuel type’ data shows that since 17 May to 4 June 2019, Britain’s generation was “coal-free” for over 18 days; the longest period yet recorded.

During this period, over 86 percent of electricity on Britain’s high-voltage transmission networks came from a combination of gas, wind, nuclear and biomass fuel types.

The five interconnectors linking Britain with Ireland and continental Europe provided the remainder of Britain’s transmission system needs, alongside a small portion of hydro generation.

Fuel mix graph for May 2019

You can see the latest generation information in the BMRS portal by clicking on generation fuel type and then ‘current summary’ which is updated each half hour.

Negative Imbalance Prices are more frequent

Negative Imbalance Price periods tend to occur when more electricity is being produced than is needed, and a higher proportion of the fuel mix is from weather dependent generation. During the ‘coal-free period’, 3.2% of Settlement Periods had a negative Imbalance Price.

Most (79%) of the negatively priced Settlement Periods occurred during the Sunday and Monday of the May Bank Holiday weekend (26-27 May). We have seen almost three times as many negatively priced Settlement Periods in 2019 than the same period last year.

You can access our Imbalance Price data on BMRS, with the latest prices published every 30 minutes.

Further reading

More information about historical negative imbalance prices is available in Emma Tribe’s ELEXON Insights article Imbalance Prices go negative on 24 March 2019.


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