Implementation of BAL-002-2 Dede Subakti Public Public
Agenda • Background information • Impact assessment • Issue statement • Implementation options • Request for comments Page 2 Public
Background Information • NERC BAL-002-2 was approved by FERC on January 19, 2017 and has effective date of January 1, 2018 • Along with the BAL-002-2, FERC also approved the new definition of Balancing area Contingency Event (BCE) as well as definition of Most Severe Single Contingency (MSSC) http://www.nerc.com/FilingsOrders/us/FERCOrdersRules/Order%20No.%20835%20 approving%20BAL-002-2.pdf • These changes will result in an increase to ISO’s operating reserve requirement, which in turn will necessitate modification of the operating reserve target procurement Page 3 Public
Background Information – Definition of BCE Balancing Contingency Event (BCE) Any single event described in Subsections (A), (B), or (C) below, or any series of such otherwise single events, with each separated from the next by one minute or less. A. Sudden loss of generation: a. Due to i. unit tripping, or ii. loss of generator Facility resulting in isolation of the generator from the Bulk Electric System or from the responsible entity’s System, or iii. sudden unplanned outage of transmission Facility; b. And, that causes an unexpected change to the responsible entity’s ACE; B. Sudden loss of an Import, due to forced outage of transmission equipment that causes an unexpected imbalance between generation and Demand on the Interconnection. C. Sudden restoration of a Demand that was used as a resource that causes an unexpected change to the responsible entity’s ACE. Page 4 Public
Background Information – Definition of MSSC Most Single Severe Contingency The Balancing Contingency Event, due to a single contingency identified using system models maintained within the Reserve Sharing Group (RSG) or a Balancing Authority’s area that is not part of a Reserve Sharing Group, that would result in the greatest loss (measured in MW) of resource output used by the RSG or a Balancing Authority that is not participating as a member of a RSG at the time of the event to meet Firm Demand and export obligation (excluding export obligation for which Contingency Reserve obligations are being met by the Sink Balancing Authority). Page 5 Public
Impact Assessment • Although CAISO is not the Transmission Operator of the Pacific DC Intertie (PDCI), the contingency of PDCI fits definition of BCE under item B Sudden loss of an Import, due to forced outage of transmission equipment that causes an unexpected imbalance between generation and Demand on the Interconnection • Historical analysis showed that import into CAISO Balancing Authority Area from PDCI varies. The maximum energy imported utilizing PDCI could approach 2400 MW. • This could lead to increased operating reserve requirement in order to meet the MSSC. Page 6 Public
Issue Statement • BAL-002-WECC-2a requires the CAISO to procure and maintain operating reserve to meet the greater of – Load requirement (3% gen+3% load) – MSSC • MSSC will be the greater of » The largest Online Resource » Import utilizing the PDCI • The amount of Import from PDCI is cleared from market optimization and varies based on cleared bids. This may include intertie schedules that do not use ISO share of the PDCI. Scheduling coordinators may use a non ISO TSP on the PDCI and then sink a schedule to the CAISO at a different intertie. Page 7 Public
Short-Term Implementation Options • Option 1: Maximum procurement of operating reserve – Procurement of operating reserve to the maximum PDCI schedule import limit to the ISO (i.e procure up to 2400 MW) • Option 2: Estimated procurement – Procurement of operating reserve in DAM based on historical regression analysis and adjust RTM for any potential shortage • Option 3: Hybrid approach – Procurement of operating reserve in DAM based on historical regression analysis and adjust limit incremental PDCI imports to based on procured reserve. Page 8 Public
Short-Term Option 1 – Maximum procurement • CAISO will procure up to PDCI schedule limit of operating reserve in DAM and RTM (maximum expected usage, will adjust up if actual schedules using the PDCI increase above 2400 MW. • Pros: – Ensure sufficient operating reserve for real time operations to meet reliability standards – Flexibility in real time import in PDCI up to its full TTC • Cons: – Potential over-procurement of the minimum standards requirement of operating reserve Page 9 Public
Short-Term Option 2 – Estimated procurement • CAISO will perform regression analysis on operating reserve requirement based on daily actual usage of PDCI. This number will be set as the target operating reserve for DAM run. There will be hourly MSSC which will set different hourly reserve requirement. • Following DAM cleared values, the CAISO will perform analysis to identify if it has sufficient operating reserve to cover PDCI import. • Pros: – Less potential for over-procurement of operating reserve • Cons: – Moving target of MSSC – Potential infeasibility of operating reserve procurement in the RTM. (if there is infeasibility, CAISO will need to manually reduce PDCI import to ensure that it has sufficient operating reserve) – Potential standards compliance risk Page 10 Public
Short-Term Option 3 – Hybrid procurement • CAISO will perform regression analysis on operating reserve requirement based on daily actual usage of PDCI. This number will be set as the initial target operating reserve for DAM run. There will be hourly MSSC which will set different hourly reserve requirement. • Following DAM cleared values, the CAISO will perform analysis to identify if it has sufficient operating reserve to cover PDCI import. • May limit incremental PDCI schedules to ISO based on procured operating reserve • Pros: – Less potential for over-procurement of operating reserve • Cons: – Moving target of MSSC – Potential infeasibility of operating reserve procurement in the RTM. (if there is infeasibility, CAISO will need to manually reduce PDCI import to ensure that it has sufficient operating reserve) – Potential standards compliance risk Page 11 Public
Potential Future Work • CAISO is working to modify its Full Network Model to add additional resource ID at Sylmar and Victorville so it can identify PDCI import that are wheeled through the DC line and sinking into CAISO BA • CAISO will require any import sinking into CAISO BA to be utilizing either one of these points: – CAISO NOB – CAISO Victorville_DC – CAISO Sylmar_DC • The goal is to determine reserve requirement due to total DC schedules that sink into CAISO BA. – Total Schedule = NOB+Victorville_DC+Sylmar_DC Page 12 Public
Potential Future Work • There could be similar condition for Pacific AC Intertie • During planned outage of the 500kV line, a single contingency could trigger automatic generation drop that will result in imbalance between generation and Demand on the Western Interconnection Page 13 Public
Request for Comments • The CAISO is looking for long term solution in the form of co-optimizing energy award/unit commitment with the reserve requirement. Possible modeling changes that will require significant software changes • The CAISO needs to find a short term solution for January 1, 2018 and is requesting comments on the three options discussed no later than December 8, 2017 Page 14 Public
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