2.3.2 The Delivery Proportion $ DP_{s,j} $ is defined as the ratio of actual MW delivery to Contracted Capacity. This ratio is a value that represents a percentage and rounded to two significant figures to ensure it represents a whole percentage.
2.3.3 The Grace Factor determines the acceptable under-delivery for a Dispatch Group. For every % point under that level, called the Penalisation Multiplier, $ (PM) $ of the full payment is deducted. Over-delivery is capped, and paid at Contracted Capacity.
2.3.4 Thus, the Payment Proportion is a value between 0 and 1 (or 0 and 100%). The calculation contains two separate cases:
if $DP_{s,j} \geq (1 - GF)$, $PP_{s,j} = 1$
if $DP_{s,j} < (1 - GF)$, $PP_{s,j} = Max(0, 1 - GF - PM$. $[1 - GF - DP_{s,j}])$
2.4.1 The total Utilisation Payments due for a given Dispatch Group in a month is calculated as the sum of the individual Utilisation Payments:
$$ M U P_{s,m}=(\sum_{e\in{\cal M}}\quad U P_{s,e}) $$
2.5.1 At month end, Availability Payments are subject to a monthly reconciliation based on the Dispatch Group's Utilisation performance over the month.
2.5.2 The Monthly Delivery Proportion ( $ MDP_{s,m} $) is the capped average of all delivery proportions for a given Dispatch Group and month, calculated as follows;
Where:
$$ M D P_{s,m}\;=\frac{\sum_{e\;\epsilon\;E m}\;M i n(1,E P_{s,e})}{\#E_{m}} $$
$ e \in E_{m} $ is the Delivery Proportion during each and every Event in the set of Events for the month (m).
# $ E_{m} $ is the number of Events in the month.
Min $ (1,EP_{s,e}) $ caps the Delivery Proportion during each Event at 100%, even if the Dispatch Group over-delivers.
$ EP_{s,e} $ Event Proportion for each Dispatch Group (s) and Event (e) as defined below.
$ EP_{s,e} $ Event Proportion for each Dispatch Group (s) and Event (e) as defined below.
2.5.3 In order to define the Event Proportion (EP), we first need the Event Delivery Proportion (EDP). For each individual Event the total, uncapped Delivery Proportions for each Utilisation Settlement Period are summed.
$$ EDP_{s,e}=(\sum_{j=ST_{e}}^{FT_{e}}=DP_{s,j})/(FT_{e}-ST_{e}+1) $$
2.5.4 As such, the Delivery Proportion for each Utilisation Settlement Period of the constraint Utilisation event is calculated. It is important to note that this is uncapped. This does not apply across Events in the month, as with the $MDP_{s,m}$ calculation.