NERC TPL Standard Issues

1. NERC TPL Standard Issues TSS Meeting #146 Seattle, WA August 15-17, 2007 Chifong Thomas

2. Recap – FERC Order 693 • Requirements for Transmission Planning(TPL) Standards

3. TPL: Transmission Planning – Transmission Planning Process: • FERC is not proposing a fundamental shift in the way planning is done for the Bulk-Power System. • Directed NERC to consider, through the Reliability Standards process, the integration of the first four of these TPL standards (TPL-001-0 to TPL-004-0) into a single standard. • Directed NERC to submit in an informational filing, in addition to regional criteria, all utility and ISO/RTO differences in transmission planning criteria that are more stringent than the TPL group of standards.

4. TPL: Transmission Planning – Sensitivity Studies and Critical System Conditions: • The purpose of these studies is not to identify remedial actions, but to assist in mitigation planning and that FERC will not be requiring the construction of additional facilities.

5. TPL: Transmission Planning – Element-Based vs. Event-Based Contingencies: • Contingency planning should reflect what would happen in the actual system, as opposed to a generic situation, and FERC directed the ERO to submit modifications to Category B of Table 1 consistent with this approach. • Probabilistic approaches to planning should be submitted to NERC for approval as a regional difference, if they are to be used in a region. • Directed the ERO to consider emergency plans and restoration resulting from cyber security-based events.

6. TPL: Transmission Planning –Spare Equipment Strategy: • FERC discussed the need for a spare equipment strategy, particularly for equipment with long lead times for replacement and affirmed its authority on these matters. • Directed the ERO to modify the Planning Reliability Standards to require the assessment of planned outages consistent with the entity’s spare equipment strategy and to clarify specific elements of this standard.

7. TPL: Transmission Planning –Resource Information for Planning: • FERC discussed issues concerning the availability of resource information, including new generation and the retirement of existing generation, on the planning process. • However, FERC did not direct any modifications to the standards at this time.

8. TPL: Transmission Planning –Sharing Information with Other Systems: • Directed the ERO to modify the standard to provide for sharing of information with neighboring systems.

9. System Performance Under Normal (No Contingency) Conditions (TPL-001-0) • Purpose: To ensure that the Bulk-Power System is planned to meet the system performance requirements under normal conditions by requiring annual evaluation of planning for these conditions and appropriate documentation. • Decision: Approved as mandatory and enforceable • Directed NERC to modify the standard to • Require that critical system conditions and study years be determined by conducting sensitivity studies with due consideration of specific factors • Require a peer review of planning assessments with neighboring systems • Modify Requirement R1.3 to substitute the reference to the regional reliability organization with a reference to the Regional Entity • Address concerns regarding footnote (a) of Table 1, including the applicability of emergency • ratings and consistency of normal ratings and voltages with values obtained from other standards. • Decided not to require planned outages at load levels for this standard, • Direct NERC to modify the standard to require assessments of outages of long lead time equipment.

10. System Performance Following Loss of a Single Element (TPL-002-0) • Purpose: To ensure that the Bulk-Power System is planned to meet the system performance requirements, with the loss of one element, by requiring annual evaluation of planning for these conditions and appropriate documentation. • Decision: Approved as mandatory and enforceable. • Directed NERC to modification to the standard that: • Requires that critical system conditions be determined in the same manner as for TPL-001-0 • Requires assessments of planned outages of long lead time critical equipment consistent with the entity’s spare equipment strategy • Requires all generators to ride through the same set of Category B and C contingencies as required by wind generators in Order No. 661, or to simulate those generators that cannot ride through as tripping • Requires documentation of load models used in system studies and supporting rationale for their use • clarifies the phrase “permit operating steps necessary to maintain system control” in footnote (a) and the use of emergency ratings; • clarifies footnote (b) in regard to load loss following a single contingency, specifying the amount and duration of consequential load loss and system adjustments permitted after the first contingency to return the system to a normal operating state.

11. System Performance Following Loss of Two or More Elements (TPL-003-0) • Purpose: To ensure that the Bulk-Power System is planned to meet the system performance requirements, with the loss of multiple elements (Category C contingencies), by requiring annual evaluation of planning for these conditions and appropriate documentation. • Decision: Approved as mandatory and enforceable. • Directed NERC to modification to the standard that: • Requires that critical system conditions be determined in the same manner as for TPL-001-0 • Modifies footnote (c) to Table 1 to clarify the term “controlled load interruption” • Requires applicable entities to define and document the proxies necessary to simulate cascading outages • Tailors the purpose statement to reflect the specific goal of the standard.

12. System Performance Following Extreme Events (TPL-004-0) • Purpose: To ensure that the Bulk-Power System is planned to meet the system performance requirements, with an extreme event involving the loss of multiple elements (Category D contingencies), by requiring annual evaluation of planning for these conditions and appropriate documentation. • Decision: Approved as mandatory and enforceable. • Directed NERC to modification to the standard that: • Requires that critical system conditions be determined in the same manner as for TPL-001-0 • Requires the identification of options for reducing the probability or impacts of extreme events that cause cascading • Requires that, in determining the range of extreme events to be assessed, the contingency list of Category C be expanded to include recent and other possible extreme events as discussed by FERC • Tailors the purpose statement to reflect the specific goal of the standard.

13. Regional and Inter-Regional Self-Assessment Reliability Reports (TPL-005-0) • Purpose: To ensure that each regional reliability organization conducts reliability assessments of its existing and planned regional bulk electric system by requiring evaluation of planning for these conditions and appropriate documentation for the current year, over five years and for longer-term planning horizons. • Decision: Not approved, pending receipt of additional information from the ERO. • FERC urges the ERO to monitor technical conferences and regional meetings in the Order No. 890 docket to obtain industry input on regional planning and use the results for developing this standard.

14. Assessment Data From Regional Reliability Organizations (TPL-006-0) • Purpose: To ensure that the data necessary to conduct reliability assessments is available by requiring the regional reliability organization to provide NERC with Bulk-Power System data, reports, demand and energy forecasts, and other information needed to assess reliability. • Decision: Not approved, pending receipt of additional information from the ERO.

15. New (and Improved?) TPL Standards • New Steady State Table • New Stability Table • East-West Differences in Transmission Planning Approaches • More new ideas

16. Differences in Transmission Planning Approaches • Eastern Interconnection: • Base cases model firm transactions to determine transmission investment to meet peak load • Make up gaps in Resource Requirements based on Market Rules • Therefore cannot drop generation without dropping load, therefore gen drop not allowed for N-1 • Western Interconnection: • Base cases model stressed Path Flows – include firm and economy transactions => transmission will not impede commerce • Paths are stressed a group at a time to develop portfolio(s) of stressed conditions

17. Work in progress • New proposal: • 3 buckets: • Bucket 1 - Firm contracts and market rules • Bucket 2 - Reasonably stressed case • Bucket 3 - Sensitivities, e.g., weather, stress the system to the breaking point(s)

18. Concerns • Unconditioned use of RAS for the stressed cases -- we should not have to show that the system is stressed before RAS is allowed. • If we develop the stressed case and demonstrate that we meet performance requirements, we should not have to also develop the unstressed "base case" and demonstrate that system performance meet requirements • We should use stressed cases for interconnection studies • We should change the name of the bucket 1 "base case" to something more descriptive.

19. Next Steps • Next Drafting team meeting in Atlanta – expect to post standard after meeting • WECC to try to remove restriction on use of gen drop and load shedding