Enhanced Curtailment Calculator (ECC) Task Force Joint Guidance Committee

1. Enhanced Curtailment Calculator (ECC)Task ForceJoint Guidance Committee Presentation and Motion to the OC & MIC Standing Committee Meetings March 27-29, 2012

2. Enhanced Curtailment Calculator, ECC ECC Task Force Members • OC - Brenda Ambrosi – BC Hydro • OC - Carl Dobbs – WAPA CA • OC - David Lunceford - CAISO • MIC - Raj Hundal – Powerex • MIC - David Lemmons – Xcel (Vice Chair) • MIC - Doug Reese – Tri-State • WECC RC - Linda Perez (Chair) • WECC RC - Jeff Sundvick (acting Chair)

3. ECC Task Force Motion • The MIC and the OC support the investigation into the development of an ECC tool with the following capabilities and associated budget estimate: • The ability to unload overloaded BES elements. • The ability to identify every significant contributor to BES facility or path loading, including contributing schedules and contributing generation. • The ability to be predictive in nature. • The ability to integrate load and generation forecasts into the solutions.

4. ECC Task Force Motion (Cont) • The ability to calculate Power Transfer Distribution Factors (PTDFs) and Outage Transfer Distribution Factors (OTDFs) based on real-time conditions. - The creation and seamless integration with a centralized outage management tool. • The ability to add system elements as needed in real-time for analysis and possible mitigation. • The ability to ensure Transmission Priority is used in conjunction with TDFs for schedule curtailments. • The ability to incorporate sub-hourly schedules.

5. ECC Budget Estimates FY2013-14 • ECC Tool $0.8 million - Equipment (servers and other large equipment) • Software (licenses or software purchases) • Communication upgrades • WECC RC Facility Remodel $1.5 million • Building additions & structural changes • Furniture & Fixtures • WECC RC O&M $1.8 million Includes: • Shift, mapping, outage, tools & training FTE’s (11) • Software recurring license & fees • Continued maintenance, IT & equipment

6. Enhanced Curtailment Calculator, ECC • Objective The ECC project seeks to improve the wide-area view of Reliability Coordinators (RCs) in the Western Interconnection such that they better understand the current operating state of the bulk electric system and are better equipped to assign relief obligations during periods of transmission congestion that are more representative of those actually contributing to the congestion.

7. Enhanced Curtailment Calculator, ECC • Problem Statement The ECC project was initiated in response to WECC members seeking to improve the tools used by the RCs to monitor the operation of the Bulk Electric System and thereby ensure reliability for the interconnection. The area identified as needing improvement is the ability to identify and then take appropriate actions to reduce loading on facilities when the facilities are at or very near their System Operating Limit (SOL).

8. Enhanced Curtailment Calculator, ECC • Problem Statement (cont.) The current congestion tool, webSAS, is only used to calculate curtailment responsibility on six Qualified Transfer Paths. It does not calculate tag curtailments with respect to transmission priority, account for sub-hourly or untagged schedules, determine generation for potential redispatch, or calculate distribution factors based on current system conditions and topology. As increased amounts of variable generation penetrate the interconnection it will be necessary for these calculations to interface with SCADA data to provide reliable analysis in near real-time.

9. Enhanced Curtailment Calculator, ECC • Scope The proposed ECC would calculate impacts on many more paths or distinct elements; potentially all rated paths; and some additional, currently unrated paths. The proposed enhancements would allow real-time updates of transmission system data to include actual generation and outages (currently the data is updated twice annually) and a more granular model of the physical system.

10. Enhanced Curtailment Calculator, ECC • Benefits Accounts for all tagged and untagged system flows. • Tagged flows represent flows scheduled using an e-tag on a specific circuit or path Untagged flows represent (parallel flows) Tagged flows scheduled on parallel circuits flowing on different circuits than scheduled due to impedance Untagged flows coming from generation or to a network/native load within a BA • WECC UFAS currently recognizes the issue of parallel flows, but the mitigation only considers tagged energy transactions

11. Enhanced Curtailment Calculator, ECC • Benefits Allows for real-time updates of transmission system data to include actual generation and outages. Current process uses seasonal topology and does not represent real-time operating values Real-time updates would allow for more accuracy of models and actions taken based on the model has less error likely The better data could help reduce the actions needed to address overloads Do we want a bullet talking about the requirements in NERC standards?

12. Enhanced Curtailment Calculator, ECC • Benefits Facilitates pro forma tariff compliance by transmission providers to perform pro rata curtailment calculations based on transmission and/or generation priority. • On March 15, 2012 the WECC Board unanimously approved the Unscheduled Flow Guidelines for curtailment calculations based on the NERC transmission priority. • The order of relief requirements would start at the lowest NERC Priority 0 through the highest NERC Priority 7 on the complete path from source to sink.

13. Enhanced Curtailment Calculator, ECC • Benefits Provides greater accuracy and system topology for reliable congestion management decisions by the RC’s and Transmission Operators. - A more granular model of the physical system should result in better decision-making - Using real-time system topology data will result in more accurate congestion management - Allows a forward view to see potential problems based on known or expected changes to the system - Improves accuracy of system topology by integrating current RC outage management tools with the WECC planning model and the ECC tool.

14. Enhanced Curtailment Calculator, ECC • RC View of Benefits - The WECC Unscheduled Flow Mitigation Plan (UFMP) is an Interconnection-wide transmission load relief procedure used to mitigate overloads attributed to unscheduled flow on qualified paths. There is specific criteria that must be met for a path to qualify under this plan. Only 6 of the 66 WECC Transfer Paths identified in the most recent WECC Path Rating Catalog meet the criteria. The criteria includes, but is not limited to, the following:

15. Enhanced Curtailment Calculator, ECC • RC View of Benefits The Transfer Path must be a transmission element or elements across which: • Schedule (MW) can be established, • Actual Flow (MW) is metered, and • Maximum Transfer Limit has been established and published in WECC Planning Coordination Committee or WECC Operations Committee documents. An historical record exists to document that: • For at least 100 hours in the most recent 36 months, Actual Flow across a Transfer Path (MW) has exceeded 97 percent of the Maximum Transfer Limit in MW, and at the same time

16. Enhanced Curtailment Calculator, ECC • RC View of Benefits WECC Standard IRO-006-WECC-1 requires the Reliability Coordinator (RC) to approve or deny UFMP requests of Step 4 or greater within five minutes. The RC monitors the OATI webSAS tool and the WECCNet messaging system to identify such requests.

17. Enhanced Curtailment Calculator, ECC • RC View of Benefits The USMP is the only Interconnection-wide plan that exists within the West. The RCs are reliant on their own system knowledge and individual BA/TOP procedures to identify available mitigating actions outside of the USMP. While there are several instances where multiple entities have coordinated to identify agreed upon actions for congestion management , the majority of existent procedures are TOP-specific and include mitigating actions to be taken by a single entity. These procedures often pertain to specific conditions (i.e.  normal operation or certain outages) and provide minimal or no direction for operating under conditions not specified in the procedure.

18. Enhanced Curtailment Calculator, ECC • RC View of Benefits In accordance with NERC Reliability Standard IRO-005-3a, the RC is required to monitor current pre- and post-contingency element conditions (voltage, thermal, or stability) including applicable mitigation plans to alleviate SOL or IROL violations, including the plans viability and scope. NERC Standard TOP-007-0 requires the RC to evaluate actions taken to address such violations and, if the actions taken are not appropriate or sufficient, direct actions required to return the system with limits. (cont)

19. Enhanced Curtailment Calculator, ECC • RC View of Benefits The continued evolution of the NERC Reliability Standards has placed a greater emphasis on the monitoring of individual equipment/facility limits. The RC must maintain awareness of loading conditions across the entire Western Interconnection Bulk Electric System (BES) and be able to assist entities with forming viable mitigation plans during normal and emergency conditions. The RC may issue directives as required to mitigate conditions that could affect the integrity of the BES.

20. Enhanced Curtailment Calculator, ECC • RC View of Benefits No common mechanism or tool exists for managing congestion throughout the Interconnection. Creating such a tool would: - Enhance the RC’s ability to identify sources that could be contributing to actual and anticipated congestion in a specific area. - Improve the RC’s ability to evaluate mitigation plans to determine viability. - Provide the RC’s with a method for determining the most effective mitigating actions available to prevent and manage congestion.

21. Enhanced Curtailment Calculator, ECC • RC View of Benefits - Allow the RC to communicate and coordinate the most effective mitigating actions amongst affected entities. - Improve the RC’s capability to provide directives in a concise manner as required.

22. Enhanced Curtailment Calculator, ECC • Timeline

23. Enhanced Curtailment Calculator, ECC • WECC process going forward - If the motion is approved by MIC & OC, this estimate will be included in draft Business Plan & Budget presented to the BOD. - If the budget is approved by BOD and includes the ECC, it will then allow us to proceed to RFP. • If the RFP and staff costs are still below budget, no further approvals are necessary to proceed. • If costs exceed the budget estimate significantly, we will need to re-visit the proposal with the BOD and Task Force.

24. Enhanced Curtailment Calculator, ECC • Roles & Responsibilities of BAs, TOPs, and RC

25. Enhanced Curtailment Calculator, ECC • Implementation testing and training

26. Enhanced Curtailment Calculator, ECC • Task Force status evaluation/determination by JGC after completion of deliverables.

27. ECCTF & UFAS Roles • Process to determine which nominated elements can be included in the ECC Tool. (ECCTF) • Process to use the Qualified Devices during a UFMP. (UFAS) - Ability to add elements on the fly. (ECCTF) - Modeling of specific elements (including source/sink points) for TDF calculation. (ECCTF, e.g. continue using seasonal WECC planning model with monthly updates relative to any 100kv or higher element. Or, use WWSM, six-week uploads with real-time updates.)

28. ECCTF & UFAS Roles (cont) • Determination of minimum TDF and physical impact thresholds and how they are used for curtailment evaluation. (UFAS is addressing, ECCTF can review) • Impacts, quantification, and treatment of non-tagged system uses. (ECCTF) • Training process for WECC RC and WECC BA on new procedures. (ECCTF) • Process to update and provide real time information on outages and disturbances. (ECCTF)

29. Budget Considerations & Assumptions • Resources, software, hardware, equipment, headcount, and capital improvements have all been evaluated on a preliminary basis for ECC Tool implementation. • Because of timing and a lack of a detailed specification the budget estimates are high level, involved multiple departments, and have been based upon WECC data, evaluation, and experience. • WECC staff believes the budget estimates include funds sufficient to cover all anticipated project needs at this time. More detailed estimates would be developed as part of a functional specification.

30. Budget Considerations & Assumptions • A hosted vendor solution is assumed for the ECC tool. • It is assumed that the ECC tool will be administered via the WECC RC. • Because WECC RC resources are severely strained at this time, it is assumed that additional RC staff will be required to monitor and maintain the ECC tool. • Also, because RC space is maximized at this time, it is assumed that significant structural remodeling will be required to provide space for the ECC tool and associated staff.

31. Craig L. Williams WECC Market Interface Manager Cell 801-455-9812 cwilliams@wecc.biz Questions?