1. ALLOCATION OF RbD ACROSS RELEVANT PERIOD DNOs’ comments on previous Workstream discussion ALLOCATION OF RbD ACROSS RELEVANT PERIOD DNOs’ comments on previous Workstream discussion Linda Whitcroft

2. 1 Current RbD Allocation Process  Daily Shipper AQs aggregated to one monthly AQ (by Shipper, by LDZ) in order to allocate market shares  Three “pots” used for RbD allocation – 4 sectors: (UNC E.7)  1 month sector  6 month sector  12 month sector  LDZ measurement sector (L)  special case 1 month sector

3. 2 Current process – continued RbD Sectors and Sources  1 Month Sector (M)  Sources:  DM Estimate to Actual  NDM Monthly read meters  Adjustments to Monthly read meters  Reconciliation of LSPs on CSEPs  Adjustments to LSPs on CSEPs  SSP Adjustments <1 month duration  6 Month Sector (6)  Sources:  NDM Non-Monthly read meters  Adjustments to Non-Monthly read meters  SSP Adjustments 1-4 month duration  12 Month Sector (A)  Sources:  DM Annual Resynchronisations  SSP Adjustments >4 month duration  LDZ Measurement Sector (L) (Special case 1 month sector)  Sources:  LDZ Measurement Errors

4. 3 Current process - continued  All reconciliation is allocated to one of the sectors, totalled and then divided equally across the number of months in each sector  Each monthly slice is allocated to RbD Shippers using their market shares  Maximum RbD period is 12 months. Therefore Shippers who exit the market have assurance that RbD charges will cease after this time

5. 4 Suggested process discussed at previous Workstream  Apportion all LSP reconciliations through RbD over the relevant period  Impacts  Every LSP reconciliation would have an opposite RbD allocation. On average 200,000 LSP meter reads/adjustments processed monthly, hence 200,000 sectors to calculate  Requires significant amount of data storage and processing  Need to hold daily AQs on system back to RbD start date (1.2.98)  Need to calculate and store daily market shares  Need to calculate and store total daily LDZ AQ  Off line reconciliation – impacts on off line systems/processes to store additional data  Potential issues on Shippers exiting the market (no foreseeable close-out), e.g.  terminations  voluntary discontinuance  mergers/acquisitions

6. 5 Is the focus on the right solution? Underlying issues that cause RbD allocation for inappropriate period  Portfolio data issues  Infrequent/incorrect meter readings (filter failures)  LDZ measurement errors

7. 6 Comments/Conclusions  DNOs’ assumption that draft Modification was raised to address LDZ metering issues  Scope of metering issues? – Those meting 643 notification process requirements (>£1million or >50gWh)?  If so, due to low volumes and clear trigger points an off line solution could be possible to allow RbD to be allocated across relevant period N.B. Consideration would need to be given on prospective errors and whether retrospective data would be available. Also, issues would still remain on rules for Shippers exiting the market. DNOs believe that this process is unsuitable for all LSP reconciliations due to scale, complexity and it does not address the root causes