The page below details highlighted GSP Group Correction Factors (GGCFs) data from the previous month. This data is acquired from BSC Agents and inputted to the Trading Operation Monitoring Analysis System (TOMAS) database.
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Distribution of Half-Hour GGCFs across all GSP Groups
The chart below shows the distribution of GGCFs, as per the latest Settlement Run data, for each Settlement Period in the last complete month against the previous three years. Again it shows the effectiveness of profiling, with the ideal being a narrow distribution centred on 1.
Highlights
The GCF distribution for February 2024 is broadly similar to February 2025, with both clustering tightly around 1.1. However, the 2025 distribution shows a noticeable reduction in out-of-tolerance values (i.e., those further from 1.0), with improved accuracy in consumption profiling and allocation this year.
Half-Hour Correction factors by Settlement Period volume
The following is based on Initial Settlement (SF) Run for the latest month and is weighted across all GSP Groups.
The chart below shows, for each of the day types used in profiling, a volume weighted average, such as adjusted to reflect the relative sizes of each GSP Group (in terms of total daily energy consumption), of the GGCFs across all GSP Groups by Settlement Period.
The source data are GGCFs from the Initial Settlement (SF) Run taken over the latest month for which SF data is available. The average is taken, for each Settlement Period, over the one month interval to create plots of volume-weighted GGCFs for the periods from Monday to Friday, for Saturdays and for Sundays included in the data set. It allows comparison of profiling for different day types and shows intra-day profiling effects.
Anything between 0.9 and 1.1 is considered reasonable. Values outside this range may indicate issues with load profiling or metering data.
Highlights
The increase in GCFs between 4pm and 7pm is consistent with typical domestic behaviour patterns during this time window, where households engage in energy-intensive activities such as cooking, heating, and appliance use. This period also coincides with popular television programming, contributing to synchronised residential demand across GSP Groups.
Daily Average GSP Group Correction Factor by GSP Group
The chart below is based on the latest Settlement Run for the last year.
This chart shows the daily average GGCF using the latest Settlement Run data for each GSP Group for the last year. It shows both profiling and metering effects, as per the earlier explanation on the effects of profiling and metered volumes.
Highlights
Due to major televised football matches on Friday 21st February (Leicester City vs Brentford, 8:00 PM) and Sunday 23rd February (Manchester City vs Liverpool, approx. 4:30 PM), there was a regional spike in electricity demand during the evening peak periods (Settlement Periods 36–42, i.e. 17:30–21:00). This aligns with the observed GCF increases across GSP Groups _L, _M, _N, _G, _B, _E, and _F. If the estimated volumes — especially from NHH or Smart meters where actual reads weren’t received — didn’t reflect the extra demand during the football matches, the total settled consumption would look too low. As a result, the system would see a larger gap between what actually flowed into the network (Group Take) and what was recorded, leading to higher GCFs in those regions.