1. Nexus Workgroup Mod 0473 Presentation
8th January 2014

2. Purpose of the Presentation
Explain solution in Nexus requirements
Explain some of the supporting business areas still to be developed
Clarify scope of Modification 0432

3. Legal Text for Mod 0432
The Nexus requirements are captured under Mod 432 legal text:
UNC Section E
UIG Allocation Adjustment Factors
As at the Nexus Implementation Date:
(a) all System Exit Points belong to the same category;
(b) the allocation factor in respect of the category is one (1).

4. UG Allocation Adjustment Factors

5. How this Works – Gas Nominations
At D-1, the Forecast User LDZ Unidentified Gas will be determined
Total Forecast LDZ Demand less DM Gas Nominations, NDM Gas Nominations & Shrinkage = Forecast User LDZ Unidentified
The Forecast User LDZ Unidentified Gas for an LDZ and Day will be calculated as;
Forecast Unidentified Gas x Users LDZ Nomination Quantity (sum of DM & NDM Nominations) / the aggregate for all Users of the User LDZ Nomination Quantity

6. How this Works – Gas Allocations (GFD+5)
At D+1 (upto D+5), LDZ Unidentified Gas will be determined;
Total LDZ Demand less DM Gas Allocations, NDM Gas Allocations & Shrinkage = LDZ Unidentified Gas
Unidentified Gas could be a positive or negative
The Users LDZ Unidentified Gas for an LDZ and Day will be calculated as;
Unidentified Gas x Users Adjusted LDZ Offtake Quantity (sum of DM & NDM Allocations) / the aggregate for all Users of the Adjusted LDZ Offtake Quantity
Note: The Users LDZ Offtake Quantity (sum of the Users UDQO’s for the day for all DM & NDM Supply Points) is ‘Adjusted’ by the ‘Allocation Adjustment Factor’

7. How this Works – Reconciliation
Each Offtake Reconciliation implies a change in the amount of the Unidentified Gas (UG) for the relevant LDZ and days and so in the quantity of Unidentified Gas allocated to each User.
UG Reconciliation is an equal & opposite adjustment
UG Reconciliation is calculated as;
For each reconciliation billing period, the net sum of the reconciliation quantities & values for all Offtake Recs carried out in that period is aggregated
The ‘Factors’ are used to determine the UG Reconciliation quantity for each Meter Point
The UG Rec is allocated amongst Users based on the ‘Factors’ (applied at GFD+5) to their latest Offtake Quantities (latest determined as at 10th day) over the preceding 12 months
For each User, the User Aggregate LDZ Quantity is the aggregate of the quantities allocated as offtaken by the User on all Days in that 12 month period

8. Summary
At Gas Nomination (D-1 to D) the Forecast Unidentified Gas is shared to Users based on the total Gas Nominations in an LDZ for a User
At Allocation (GFD+1 to GFD+5) the Unidentified Gas is shared to Users based on the ‘Allocation Adjustment Factor’ for a User & LDZ
Following a Meter Point Reconciliation the opposite & equal amount is shared to Users based on the Allocation Adjustment Factor based on the latest throughput (Prevailing UDQO)

9. Next Steps
UKLink Programme will develop the system based on these requirements and business rules
Flexibility has been specified on the value of the factors (they will be parameterised)
Mod 0473 proposes to define the factors to be applied by Class and AQ
On implementation of Mod 0432, if Modification 0473 is not approved in time, the factors to be applied will be 1 to all Meter Points in an LDZ.