This area contains data used by National Grid to calculate Triads in accordance with the Statement of Use of System Charging Methodology (see section 14 of the CUSC).
The Triads are the three half-hour settlement periods with highest system demand and are used by National Grid to determine charges for demand customers with half-hour metering and payments to licence exempt distributed generation. They can occur in any half-hour on any day between November to February inclusive but are separated from each other by at least ten full days.
The Triads are determined after the event using Elexon settlement metering data for November to February. This data is usually available around 24 March following which National Grid will confirm the Triad half-hours. Once confirmed they are not updated for subsequent settlement data. Indicative Triads based on data received to date can be found on Elexon's Electricity Data Summary.
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