Report of the Planning Coordination Committee WECC Board Meeting Albuquerque, NM December, 2007

2 PCC Agenda Approval Items Revisions to the WECC Power Supply Assessment Policy Power Supply Assessment (PSA). Information Items Facility Rating Process

3 Changes to the Policy Current policy approved in 2000 and revised in 2002 Proposed substantive updates Specifies assessments shall consider capacity and energy Adds fuel supply interruption as potential uncertainty for future evaluation, an issue of interest to NERC Describes building blocks generally and characterizes them as initial adequacy guidelines, giving WECC a specific reference in policy for external parties Removes direction to calculate probabilities of serving load (will still be area of future LRS exploration) Creates a communication mandate to states and others

4 Proposed Motion The PCC recommends that the WECC Board approve the revisions of the WECC Power Supply Assessment Policy prepared by LRS.

5 Power Supply Assement History Aim: replace the Power Supply Design Criteria (PSDC) for WECC resource adequacy assessments LRS has been developing a bottom-up approach based on building blocks October 2006 PCC meeting: Described initial components in qualitative terms March 2007 PCC meeting: More detailed description of components being considered July 2007: Board approved the Building Block approach LRS made changes based on feedback October 2007: PCC unanimously approved the Assessment

Power Supply Assessment Two resource levels Class 1 – reported to be under construction and in- service by January 2011 Class 2 – reported to be under regulatory review and in-service by January 2013 Other reported resources (Class 3) listed but not used in analysis Cases, combinations of: Summer and winter Building block margins and flat 15% margin Extreme temperature scenarios, for only

7 Adequacy Reserve Margin Components Calculated by BA, applied by sub-region Components Contingency reserves from NERC/WECC standards Regulating reserves from NERC/WECC standards Reserves for additional forced outages that would require rebuilding contingency reserves – estimate from outage data Reserve for additional load caused by 1-in-20 temperatures

8 Response to Comments from Last Meeting Added appendix clarifying that PSA margins are not intended to supplant any margins ordered by regulatory agencies nor are they directly comparable to the margins an individual LSE or regulator might use to evaluate adequacy Did modify the calculation for California LSEs within ISO footprint to address aggregation issues Looked at effect of wind machines at 0% capacity factor – negligible in this PSA but an issue for future PSAs

9 Adequacy Reserve Margin Values in PSA Sub-area SAM Bubbles Included in Sub- area SummerWinter Margin CanadaBC, Alberta12.0%12.8% Southwest Arizona, N. Mexico, S. Nevada, IID, Four Corners, Palo Verde 15.7%14.6% NorthwestPacific Northwest, COB, Montana13.7%16.3% BasinIdaho, Utah, N. Nevada12.8%13.5% N. California N. California, Central California, San Francisco, SMUD 16.5%12.2% S. California/MexicoS. California, San Diego, LADWP, CFE, IPP16.6%13.0% Rocky MountainsColorado East, Colorado West, Wyoming14.2%15.4%

10 Power Supply Margin by Sub-region – Summer, Class 1 Resources Only

11 Power Supply Margin by Sub-region – Summer, Class 1 and 2 Resources

12 Power Supply Margin by Sub-region – Winter, Class 1 and 2 Resources

13 Response to Current Comments – 1 Comment: PSA assumes all existing resources remain in service. PSA should acknowledge uncertainty about aging plants, e.g., ~4,400 MW in N. California. Response: L&R data request asks for known retirements. Issue especially complex in California because of limited future resource info available to CAISO. BA vs. LSE and/or market knowledge is ongoing problem. An issue for next years PSA.

14 Response to Current Comments – 2 Comment: Recommend WECC develop rules for counting resources based on completion of milestones. Response: LRS will continue to look at the categorization of new resources in the L&R data request and in the PSA. Biggest problem is lack of BA knowledge. Comment: In future PSAs, WECC should adjust the adequacy metric to reflect changing mix of resources, especially increasing amounts of intermittent and non- dispatchable resources. Response: LRS will examine this issue further in future PSAs. Because of how we used resource class categories this is less of an issue this year.

15 Future Work Continue evaluation of data needs and data requests, including by other WECC users, e.g., TEPPC Adequately recognize energy constraints on the system Particularly, constraints on NW hydro operation and effect on capacity available to meet load Review, perhaps expand, building blocks and calculation of numerical values Examine use of Promod, or other models, for adequacy analysis Continue to improve consistency of WECC resource adequacy reports with NERC adequacy reports

16 Proposed Motion PCC recommends that the Board approve the 2007 Power Supply Assessment (PSA).

17 Information Items

18 Facility Rating Process Projects Entering Regional Planning Gateway/South Gateway/West Central California Clean Energy TransWest Wyoming West Projects Entering Phase 1 (none) Projects Entering Phase 2 Juan de Fuca Path 54 Springerville Unit #4 Tot 3 Upgrade Colorado/WY (TOT3) Projects Entering Phase 3 Centennial Path Redefinition Green Path MATL Path 27