Global Aggregation Working Group 15 th September 2010

2 Global Aggregation - Recap  What is Global Aggregation?  Process of providing an aggregation for all registered Suppliers  Includes aggregation of Host Suppliers  Current implementation means Host Supplier calculated by difference  Error Supplier Unit in the SEM  Not just Host Supplier volumes but also other errors included

Data Aggregation NHH Meters (STS only) Readings AUFs and EUFs Profiled Demand for NHH customers Generator Output Tran Loss factors Units delivered to BSP in Each Jurisdiction HHM metered units Meter data processing HH Meters Readings Difference Residual volume assigned to NIEES /ESBN using Error Supplier Units Metered or profiled volumes are uplifted in DA to reflect distribution line losses Global Aggregation - Recap

Data Aggregation Readings AUFs and EUFs Profiled Demand for NHH customers Include DN LLFs Generator Output HHM metered units Include DN LLFs Meter data processing HH Meters Readings Variance is ‘smeared’ across Suppliers, method to be determined through SEMO Metered or profiled volumes are uplifted in DA to reflect distribution line losses (reports show both vols) Variance Tran Loss factors Units delivered to BSP in Each Jurisdiction Global Aggregation - Recap

5  Causes of imbalance?

6 Global Aggregation - Recap  Causes of imbalance?

7 Global Aggregation - Recap  Causes of imbalance?  Elexon experience of Global Aggregation;  Incorrect profiles of non-interval meters considered chief contributor;  Modification 34_09 developed with a view to smearing residual volume across all suppliers, taking account of each suppliers share of non-interval metered consumers;

8 Global Aggregation - Recap  Mod raised by ESB CS  Mod proposed separation of SU into Interval SU and Non-Interval SU  Raised at Mods Meeting 24 ( )  Mods Panel recommended setting up Working Group to explore further  Terms of reference for Working Group circulated, Nov 2009

9 Global Aggregation - Recap  Working Group 1, held on 19 th November  Presentations & Discussion –  ESB CS suggested assigning ESU to non-competing Party under the Code;  MDPs presented on impact on systems;  Actions –  SEMO & RA to meet to further develop options;  ESB CS & NIE to provide estimation of error;  Mods Panel to decide if impact assessments should be sought;

10 Global Aggregation - Recap  SEMO & RA met December 1 st to develop options paper;  Four options written up and circulated –  Option A – recovered through SEMO balancing cost;  Option B – smear across Suppliers based on annual factors;  Option C – smear across Supplier based on monthly factors;  Option D – as set out in modification proposal;

11 Global Aggregation - Recap  Working Group 2, held on 23 rd February  Presentations & Discussion –  Suppliers presented on magnitude of actual error;  SEMO & MDPs presented results of impact assessments;  MRSO proposed option E, further enhancement on option C;  Actions –  SEMO & MDPs to meet to further review options D and E;  SEMO to impact assess options A+ and E;

12  Meeting between MRSO, NIE T&D and SEMO took place on March 5 th ;  Further review of Options D and E;  Option E confirmed as  Aggregation for Supplier Units as normal;  Inclusion of a % value for each Trading Period;  % value will indicate at a MW level the proportion of the aggregation that is made up of non-interval metering; Global Aggregation - Recap

13 Global Aggregation - Recap  Working Group 3, held on 27 th April  Presentations & Discussion –  SEMO presented on MDP meetings and further impact assessments;  EirGrid presented on TUoS impacts;  Actions –  SEMO to issue consultation on options A+ and E;  TSO to review implementation of Option A for TUoS;

14 Global Aggregation - Recap  Consultation document issued on June 17 th ;  Participants asked to express preference between Option A+ and Option E;  Responses welcomed on discarded options B, C and D;  Nine responses received to Consultation  Five responses favoured Option E (2 Participants, 3 service providers)  Three responses favoured Option A+  One response recommended either option

15 Global Aggregation - Recap  Working Group 4, held on 26 th August  Presentations & Discussion –  Recap and review of consultation responses;  Full impact assessment on SEMO systems is approx 1200 hours or €210 K  Noted flexibility in Option E to allow for implementation in one jurisdiction ahead of the other;  Stressed importance of decision;  Consensus reached on recommendation of Option E;

16 Global Aggregation - Recap Metered Generation Loss Adjusted Metered Demand by Supplier Unit MGLF - NDLFError Supplier Unit Current Design

17 Global Aggregation - Recap Metered Generation Loss Adjusted Metered Demand by Supplier Unit MGLF - NDLFError Supplier Unit Option E Design Metered Generation Loss Adjusted Metered Demand by Supplier Unit MGLF - NDLF Residual Meter Volume & Smearing

Global Aggregation - Recap  After calculation of residual error volume;  Allocated across all Suppliers in the SEM;  Residual Meter Volume Interval Proportion – sets how much of the error volume is allocated based on a Suppliers interval metered customers;  Non-Interval Energy Proportion – advises what portion of the aggregated Metered Demand is based on non-interval metered customers;