BSC Operations Headline Reports

The report provides commentary on BSC market operation, identifying key events and reporting on important data that may impact BSC Parties. It is produced on a monthly basis and covers the data from the two previous months and is based on a combination of latest and best available data.

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Content list

  • Feature on Wind Bid Volume and Flagged Actions in June
  • Regular article on Trading Charges in May
  • Regular article on Balancing Mechanism Volumes in May
  • Feature on Seasonal Changes in Offtaking TLMS
  • Feature on Low GGCFS during Daytime Settlement Periods
  • Regular article on System Prices in June

Wind Bid Volume and Flagged Actions in June

A total of -132GWh of Wind Bid volume was accepted in June. This volume was all accepted during an 11-day period between 13 and 23 June. June 14, 18 and 21 had the highest proportion of the accepted Wind Bid volume, accounting for 73% of the total in June.

Graph of Wind Bid Volume and Flagged Balcing Actions in June
Click to expand graph of Wind Bid Volume and Flagged Balcing Actions in June

The average price of an accepted Wind Bid in June was -£72.09/MWh; 98.3% of these were Flagged as system balancing in June. Flagged actions are potentially re-priced in the System Price calculation.

The highest percentage of Second-Stage Flagged actions, across all fuel types, were taken on 14, 18 and 21 June. 53% of balancing actions on 18 June were Second-Stage Flagged and therefore re-priced.

Seasonal Changes in Offtaking TLMS

This graph is an adaptation of “Daily Average Offtaking Transmission Loss Multiplier (TLM)” from the Trading Operations Report, with a number of GSP Groups removed. Following implementation of P350 ‘Introduction of a seasonal Zonal Transmission Losses scheme’ on 1 April 2018, TLMs vary by region and season.

Graph of Daily Average Offtaking Transmission Loss Multipliers (TLM)
Click to expand graph of Daily Average Offtaking Transmission Loss Multipliers (TLM)

The change in Transmission Loss Factors (TLF) on 1 June, due to the change in season from Spring to Summer, has impacted TLMs in some regions more than others.

South Scotland and North Western regions have changed the most, showing a daily decrease of 0.41% and 0.33% in their average daily Offtaking TLMs (from 31 May to 1 June). Summer TLFs in these regions remain negative, so Suppliers should benefit from the lower TLMs.

In contrast, TLMs in the South Eastern and South Wales regions have increased, by 0.36% and 0.49% respectively. The TLF for South Wales, which was negative in Spring, is now positive, increasing this region’s average daily Offtaking TLMs.

Low GGCFS during Daytime Settlement Periods

This graph is an adaptation of “GSP Group Correction Factor (GGCF) by Settlement Period” from the Trading Operations Report. GGCF values usually range between 0.9 and 1.1, while values outside of this range may indicate an issue with metered volumes.

Lower than usual GGCFs can be seen in daytime Settlement Periods on weekdays and weekends in the last month. The data includes May and June Settlement Dates at the SF Settlement Run. ELEXON has investigated the lower than usual GGCFs and no issue has been seen with metered volumes.

Graph of Weighted GSP Group Correction Factors by Settlement Period
Click to expand graph of Weighted GSP Group Correction Factors by Settlement Period

Increased solar generation not accounted for by Non-Half Hourly profiles can lead to an overestimate of consumption. Lower GGCFs in daytime Settlement Periods therefore scale down suppliers volumes to match the GSP Group Take.

Full list of reports

The BSC Operations Headline Report is produced on a monthly basis for the BSC Panel meetings, and is circulated to the Imbalance Settlement Group (ISG) as well as being published on the ELEXON website.

Please note that the reporting months are the two prior to the current month, based on a combination of latest and best available data.

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