1. MARKET SYSTEM RELEASE UPDATE Modifications Committee Meeting 31 July 2012

2. The following approved Modification Proposals were included in the release Mod_18_10: Intra-Day Trading Mod 43_10: Variable Price-Taker Generator Units and Firm Access. The release was successfully implemented on schedule overnight on Fri 20 th / Sat 21 st July. Central Market Systems were available for Trading as scheduled at 8am on July 21 st. All project milestones were completed to quality and schedule (see next slide for more detail). New capability embedded successfully: All Ex-Ante schedules (EA1, EA2 & WD1) published to schedule post deployment. SEM R2.0.0 – Intra-Day Trading – Deployment

3. SEM R2.0.0 – Intra-Day Trading – Project milestones ActivityScheduleStatus Detailed RequirementsDec 1 st, 2010 – Apr 30 th, 2011Complete Vendor Detailed DesignMay 1 st, 2011 – Jul 29 th, 2011Complete Design Deliverables Issued to Participants (MPUD etc.) Aug 29 th, 2011Complete Participant Engagement Plan publishedSep 9 th 2011Complete Participant Systems Design WorkshopsSep 28 th, Oct 5 th 2011Complete Vendor ImplementationJun 20 th, 2011 – Nov 11 th, 2011Complete Factory TestingNov14 th, 2011 - Dec 23 rd, 2011Complete System Integration TestingJan 3 rd, 2012 - Apr 27 th, 2012Complete Market TrialApr 30 th, 2012 – Jul 6 th, 2012Complete DeploymentJul 20 th, 2012*Complete

4. The Approved scope for SEM R2.1.0 is as follows: SEM R2.1.0 – Oct. 2012 – Scope Reminder Mod RefCR RefDescription Mod_40_10SEM_PC_CR254Differentiation between Dwell Times and Dwell Trigger Points While Ramping Up and Ramping Down Mod_42_10SEM_PC_CR255Changes to the Single Ramp-Up Rate and the Single Ramp-Down Rate calculation. Mod_01_11SEM_PC_CR258UI Payments for Generator Units. Mod_06_11SEM_PC_CR259Increasing maximum daily submission number and automating cancellation of Settlement Reallocation Agreements. Mod_10_11SEM_PC_CR274Interconnector Under Test. Mod_12_11SEM_PC_CR275Interconnector Unit Loss Adjustment when Exporting Mod_21_11SEM_PC_CR280UI Payments for Generator Units Constrained On SDSSEM_PC_CR207Automation of FMOC Calculation SDSSEM_PC_CR260Additional MI-AMP Feed SDSSEM_PC_CR261Removal of orphan Trading Site Settlement Points SDSSEM_PC_CR266Change of Effective Date in the MPI SDSSEM_PC_CR267Wind and Load Forecast Data SDSSEM_PC_CR286Publication of Zero MIUNs when no PQ Pairs available

5. SEM R2.2.0 – Apr. 2013 – Scope to Date The following Modification Proposals are approved for the SEM R2.2.0 release: The release cut-off date for the April 2013 release to the Central Market Systems was Friday, June 22 nd, 2012. Regarding non-T&SC scope (i.e. SDS), impact assessments are with our vendors. Once received: A meeting of the CCF will be scheduled to prioritise these for inclusion in scope; Scope Proposal will be issued to the Regulatory Authorities for approval; and Once approved, the complete release scope will be published to the Industry. Mod RefCR RefDescription Mod_17_11SEM_PC_CR281Addition of a D+3 DI report Mod_03_12SEM_PC_CR290Alignment of T&SC with Revised VAT arrangements

6. SEM R2.3.0 – Oct. 2013 – Release Cut-Off Date The release cut-off date for the October 2013 release to the Central Market Systems is: Friday February 22 nd, 2013. All approved Modifications Proposals will be allocated to this release (subject to available capacity).