Sustained Hydro Peaking Capacity Contract with Don Long Finalizing Phase II SOW Mary Johannis PNW Resource Adequacy Technical Committee Mtg January 23, 2009

PNW Resource Adequacy Technical Committee Meeting2 Reasons for Regional Analysis Help validate hourly hydro dispatch in GENESYS Simulations Data Submittals to WECC/NERC –WECC and NERC use this data for all types of studies including expected and extreme temperature scenarios –Hydro capacity provided should be the maximum capability under specified water conditions Potential use in PNUCC’s NRF and BPA’s White Book

January 23, 2009PNW Resource Adequacy Technical Committee Meeting3 Phase II SOW Iterative approach to determining maximum hydro capability over 3-day, 6 peak load hour period Starting with regional or utility load shape, subtract out utility’s non-hydro resources and purchases and then determine whether a utility’s hydro resources can meet residual load If so, increase load until hydro resources can no longer meet residual load to determine maximum sustained hydro peaking capacity

January 23, 2009PNW Resource Adequacy Technical Committee Meeting4

January 23, 2009PNW Resource Adequacy Technical Committee Meeting5

January 23, 2009PNW Resource Adequacy Technical Committee Meeting6 Amount of EnergyAlt A. The amount of energy is determined from a hydro regulation study, plus any adjustments for weekday/weekend, use of ponds and water from future period. Alt B. Project owner defines the amount of energy the project generates through use of storage and pondage (within some general guidelines-eg Jan 37 water) Alt C. ? - water yearJanuary ‘37,’93,’73 July ’44,’79,’35 - project river flowFrom NWPCC energy regulator for the specified water years. -weekday/weekend splitSome percentage above average monthly value Not defined yet - use of pondsStart full at beginning of first day Not defined yet - use extra water from future time period Yes – borrow from future days of week Refill ponds by Sunday night? Yes – from future weeks within month Alt A. 7%? Alt B. Limit defined by upstream project constraints (e.g. GCL daily draft limit)? Reservoir elevationsMonthly average elevations from energy regulation Perhaps use beginning or ending elevation.

January 23, 2009PNW Resource Adequacy Technical Committee Meeting7 Spot market purchasesYes – at discretion of project owner – no limit by project Project unit maintenanceNo reduction for planned turbine/generator maintenance Operating reserves Regulating margin No reduction in project capacity – accounted for elsewhere EncroachmentNo adjustments for individual project generation. Nets out regionally Canadian EntitlementNo reduction in project capacity – accounted for elsewhere

January 23, 2009PNW Resource Adequacy Technical Committee Meeting8 Hydro Utilities Asked to Weigh In Five Hydro utilities responded to 1/13 Two Questions: –LOAD USED TO DEFINE HYDRO CAPABILITY: Regional load shape or utility load shape hydro facilities to meet the residual load shape? –USE OF WATER AND STORAGE: Should modeling assume utilities can borrow hydro energy from future weeks? Responses: –Four agreed that regional analysis should use regional load shapes; one said with HLH some change in load shape would not be significant –Five agreed that if hydro projects can borrow energy from future weeks and would do so to meet load, then this should be allowed –Important for utilities to review and agree with analysis