NERC - MRS TTC/ATC Methodologies

NERC - MRS TTC/ATC Methodologies Presenting By Stephen Tran February 4, 2011

NERC Standards • Overview of NERC Standards • BC Hydro vs. NERC • Q & A • Next Steps

NERC Standards – Overview • FERC Order 890 determined ATC calculation lack consistency • FERC directed the industry working with NERC to draft ATC calculation Reliability Standards. • In October 2008, NERC filed with FERC six Reliability Standards • Effective date is 12 months from the date of regulatory approval • On 24 November 2009, FERC approved these Reliability Standards • Effective date is 1 April 2011 for FERC jurisdictional Transmission Providers.

ATC Requirements • Capacity Set Aside for System Needs • MOD – 028Area Interchange • MOD – 029Rated System Path • MOD – 030Flowgate • MOD – 004Capacity Benefit Margin • MOD – 008TM Reliability Margin • MOD – 001Available Transmission System Capability • TTC - ATC Methodologies NERC Standards

MOD – 001: ATC • Create/keep current ATC Implementation Document (ATCID) • Choose 1 or more of the 3 methodologies for each path • Calculate ATC & Defines update frequency • Hourly: 48 hrs (update hourly) • Daily: 31 days (update daily) • Monthly: month 2 – month 13 (update weekly) • Treatment of Counter-flows (You tell me!) • Notify and share information with applicable entities

MOD – 004: CBM • To meet planned generation reliability or resource adequacy requirements • For energy schedules under NERC EEA 2 • TP, offering CBM, to describe procedure in its CBMID • BC Hydro currently doesn’t have CBM

MOD – 008: TRM • TRMID to be created identifying amounts set aside for the following: • Aggregate Load forecast uncertainty • Load distribution uncertainty • Forecast uncertainty in Transmission system topology • Allowances for parallel path (loop flow) impacts • Allowances for simultaneous path interactions • Variations in generation dispatch • Operating Reserve actions not exceeding a 59-minute window • Reserve sharing requirements • Inertial response and frequency bias

MOD – 028: Area Interchange • NL+NITS are included in the base case, not a fixed number • Determine transfer capability above what required to serve NL and NITS • - Daily On-peak and Off-peak: once a week • - Monthly: once a month • Not generally used in WECC

MOD – 028: Area Interchange • Determination of first contingency transfer capability above (NL + NITS) requirements TTC TC above (NL + NITS) Base case (NL + NITS)

MOD – 029: Rated System Path • A West specific methodology based on WECC’s path rating study requirements • Defines inputs for creating a model • Defines studying criteria/approach • Create a list of contingencies • Determine an initial TTC • For path with existing path rating known and used since January 1994, set the TTC at existing rating • TTC is trumped by System Operating Limit

MOD – 028 Vs. MOD - 029 • Both produce similar results • MOD – 028 requires calculating TTC on a regular basis • Daily On-peak and Off-peak: once a week • Monthly: once a month • MOD – 029 requires • Calculating Initial TTC • Consideration of System Operating Limit (SOL) • BC Hydro inter-tie paths are subject to WECC Path Ratings

ATC Formulae • ATCF = TTC – ETCF – CBM – TRM + PostbacksF + Counter-flowsF • ATCNF = TTC – ETCF – ETCNF – CBMS – TRMU + PostbacksNF + Counter-flowsNF • - ETCF = NLF + NITSF + GFF + PTPF + RORF + OSF • - ETCNF = NITSNF + GFNF + PTPNF + OSNF

BC Hydro vs. NERC • BC Hydro Firm ATC Formula • ATCF = FTTC – ETCF – CBM – TRM • NERC Firm ATC Formula • ATCF = TTC – ETCF – CBM – TRM • If, TRM = TRMU + X  FTTC = TTC – X • BC HydroNERC • FTTC – TRM = TTC – TRM • TRM = TRMU

BC Hydro For Firm ATC New: ATCF = TTC – ETCF – TRM Existing: ATCF = FTTC – ETCF – TRM For Non-firm ATC New: ATCNF = TTC – ETCF – ETCNF – TRMU + Counter-Schedules Existing: ATCNF = TTC - ETCF – ETCNF – TRM + Unused ETCF + Counter-Schedules

Next Steps • Filing assessment with BCUC with recommendations • - Drafting various Implementation Documentations • - Filing Attachment C with BCUC

NERC - MRS TTC/ATC Methodologies