MPID 223 (Failure to Follow Synchronising Instruction) JGCRP 12 th November 2014 (Anne Trotter)

Background Grid Code Modification Proposal MPID 223 was presented by EirGrid and SONI at the Joint Grid Code Review Panel on 23rd February 2012 in Belfast, relating to changes to the Scheduling and Dispatch Code (SDC) that arose as a result of clarifications needed to the “Failure to Follow Notice to Synchronise”. Proposals for amendments to the Grid Codes needed as a result of the above were discussed at Joint Grid Code Review Panel Meetings on 23rd February and 24th May 2012 and were consulted upon from 23rd May 2012 until 28th June 2012.

Background cont. On 28th September 2012 EirGrid and SONI (the TSOs) issued a joint response to the consultation, which was published on the EirGrid and SONI websites In this response the TSOs addressed the points raised by the respondents to the consultation On 28th September 2012, the TSOs sought the approval of: –The Commission for Energy Regulation for the specified changes to the EirGrid Grid Code –The Northern Ireland Authority for Utility Regulation for the specified changes to the SONI Grid Code In May 2013 CER and UREGNI wrote to EirGrid and SONI and UREGNI requesting the TSOs consider a number of specific points for discussion with the Grid Code Review Panels prior to resubmitting the modification proposals

Background cont.(1) On 10 th June 2014, EirGrid and SONI responded to CER and UREGNI with a report: _to_Synchronise.pdfhttp:// _to_Synchronise.pdf showing that there is no evidence to suggest a negative or positive impact on the cost of consumption, as a result of implementation of MPID 223. At the JGCRP meeting on 11 th June 2014, it was noted that the TSOs had issued this report, on Failure to Follow Synchronising Instruction, to the Regulators. The CER requested that this item (MPID 223) be brought forward to the November 2014 JGCRP/GCRP for final discussion.

Change Being Proposed OC (EirGrid Grid Code) allows the generator 10 minutes to rectify a non-compliance. –If a strict monitoring process was to be applied the Generator would be deemed to have failed to comply with an instruction if it had not synchronised the unit within 5 minutes of the original instructed time. The generator would then have another 10 minutes to rectify the situation (i.e synchronise) or else they have failed to comply with the instruction and must declare the unit unavailable. A 15 minute window is consistent with SDC and it is the TSOs view that this built in the above timings but removed the need for formal Testing/Monitoring to trigger a re-declaration Considering the above, the TSOs consider it pragmatic to allow 15 minutes before issuing a Failure to Follow Synchronising Instruction and when issued the unit must be declared to 0 MW.

Other changes It has also been agreed with Generators as part of the business process development that the TSO can request a unit to synchronise earlier than its Notice to Synchronise time but that the instruction to the generator would reflect the Notice to Synchronise time and only be amended if the unit synchronised earlier. In the interest of completeness the TSOs believe this should be included in the Grid Code

MO and TSO Initial Analysis of the Impact of Modification Proposal MPID 223 – June 2014 A total of 7 cases of potential fail to sync events in 2013 were analysed. While maintaining the original and actual Market conditions on the trading day in question (i.e. no change to wind or system load) the availabilities of the units were changed in the Unconstrained Unit Commitment (UUC) market engine and compared to a Basecase, run for the day in question to give an indication of the change in Production Cost for the trading day and any change in average System Marginal Price (SMP). The same process was carried out in the Reserve Constrained Unit Commitment (RCUC) engine. The results indicated no real change in SMP and show both increases and decreases in production costs in both the UUC and in the RCUC.

MO and TSO Initial Analysis of the Impact of Modification Proposal MPID 223 – June 2014 The market engine is designed to optimise the most economic dispatch to meet the schedule demand. In real time the TSOs need to schedule reserve and invariably there are differences in the forecast demand and the actual demand and in the forecasted generation from wind and actual generation from wind. Units which are synchronising (and therefore potentially failing to synchronise) can be more expensive units and therefore there is a higher probability that such unit(s) will not have been scheduled in the economic dispatch in the UUC market engine.

MO and TSO Initial Analysis of the Impact of Modification Proposal MPID 223 – June 2014 In the case where a unit fails to synchronise, the TSOs review the demand, wind forecast, interconnector flows, and performance of other units and make a decision to: 1.Operate the system with the increased cost of holding the required amount of reserve. (If there is a greater unreliability of units synchronising, long term this could increase the amount of reserve TSOs need to hold which increases reserve costs directly impacting the consumer). or 2.Start another more expensive unit (or perhaps a cheaper unit, as the unit failing to synchronise may be part of a Transmission Constraint Group)

MO and TSO Initial Analysis of the Impact of Modification Proposal MPID 223 – June 2014 Transmission Constraints exist in both Transmission System Operators (TSOs) in Ireland and Northern Ireland. This means Generation Units, which are not run in the market, need to be constrained on for system security reasons. If any of these “constrained on” units subsequently fail to synchronise, the production cost is reduced as cheaper units are run. However there may be an increased risk due to system security being reduced. It must be noted the TSOs continue to operate the power system prudently within an acceptable level of technical operating parameters.

Implication of not Implementing MPID 223 Potential ongoing confusion in the interpretation of the obligations of Generators with regard to ‘Failure to Follow Notice to Synchronise’ Potential for different implementation of Failure to Follow Notice to Synchronise in Ireland and Northern Ireland.