Where:
APs,w = (sum from j = STw to FTw of ACs.SPa.CCs.SAs,j)
APs,w is the Availability Payment for a Dispatch Group (s) during an Accepted Availability Window (w) sum from j = STw to FTw of sums the payment for every Availability Settlement Period in the Accepted Availability Window, from start to finish time inclusive ACs,w is the Availability Cost for that Dispatch Group and Accepted Availability Window on a £ per MW per hour basis SPa is the Availability Settlement Period CCs is the Contracted Capacity SAs,j is a binary value representing Dispatch Group availability in each Availability Settlement Period.
2.2.1 For a Dispatch Group (s), Utilisation Payments for Sustain, Dynamic and Secure Services are calculated per Event (e). Each Event has a start time (STe) and a finish time (FTe), such that STe < FTe.
2.2.2 The Utilisation Payment for a Dispatch Group (s) per Event (e) is calculated as follows:
Where:
UPs,e = sum from j = STe to FTe of CCs.UCs.SPu.PP(CCs,ADs,j)
Us,e is the Utilisation Payment for a Dispatch Group (s) during each Event (e)
Us,e is the Utilisation Payment for a Dispatch Group (s) during each Event (e) sum from j = STe to FTe of sum of the Utilisation Settlement Periods during the constraint Utilisation event, CCs Contracted Capacity UCs Utilisation Cost SPu Utilisation Settlement Period of the Dispatch Group, as defined above ADs,j is the actual, metered MW delivery of the Dispatch Group (s) for each Utilisation Settlement Period during the Event (j). In the payment calculations, there is no difference between Generator Sites and Demand reduction Sites, since this value is the 'reported to grid' value PP is the Payment Proportion, being the fraction of the full price due for every Utilisation Settlement Period based on delivery performance
2.3.1 A margin of error, known as the Grace Factor (GF) is allowed in respect of under-delivery of the Contracted Capacity (CC) for a Dispatch Group. Delivery of equal to or greater than the required level of Contracted Capacity less the applicable Grace Factor is awarded the full Utilisation Payment. A deduction from the full payment will be made for delivery of less than the required level of Contracted Capacity less the applicable Grace Factor.