1. January 29, 2010Resource Adequacy Steering Committee 1 Sustained Peaking Capacity Analysis Initiated by the Adequacy Forum Input Information from Utilities Assembled by Don Long

2. January 29, 2010Resource Adequacy Steering Committee 2 PNW Sustained Hydro Peaking Capacity Analysis Study Goal: –Perform a “bottom-up” assessment of the sustained peaking capacity of the Pacific Northwest Hydro System over the highest 18 hours in a 3-day cold snap or heat wave under critical, adverse and average water conditions. Study Purposes : –Inform Hydro utilities’ resource planning efforts –Assure consistent assumptions are used for individual sustained hydro peaking studies, such as assumed flows on common tributaries –Provide a check of the GENESYS-based Regional Sustained Hydro Peaking Capability result –Help assure consistent reporting of hydro capacity to the Western Electricity Coordinating Council’s Loads and Resources Subcommittee (WECC LRS) and the Pacific Northwest Utilities Conference Committee (PNUCC).

3. January 29, 2010Resource Adequacy Steering Committee 3 Inputs Council provides regional load shape Some utilities chose to model their own hydro generation, submit hourly info for 3-day events: –Generation –Flow –Purchase assumptions Other utilities asked consultant to model for them (utility provides modeling data and purchase assumptions) Consultant also responsible for consistency of assumptions (e.g. upstream discharge is in-line with downstream inflow)

4. January 29, 2010Resource Adequacy Steering Committee 4

5. January 29, 2010Resource Adequacy Steering Committee 5 Output “Bottom-up” assessment of hydro sustained peak capability for January Cold Spells and July Heat Waves, for 3 water conditions Details of utility study to remain confidential between consultant and utility, other than reporting 1-hour and 18-hour peak capacities. Aggregate purchase assumptions for all utilities will be compared with assumptions used in the PNW Resource Adequacy Standard. Documentation of methodology to allow the analysis to be repeated (at least every 3 years)

6. January 29, 2010Resource Adequacy Steering Committee 6 Status Completed: –By utilities: Avista (Clark Fork), EWEB, Federal System (except Elwha River), Idaho Power, PGE, Tacoma –By consultant: Avista (Spokane River), Bonners Ferry, City of Centralia, Chelan PUD, Douglas PUD, Energy Northwest, Fall River REA, Grant PUD, Lewis County PUD, Pend Oreille PUD, PPL Montana In progress: –By consultant: City of Idaho Falls, City of Portland, Snohomish, Twin Falls Hydro, Warm Springs Tribe Data or studies needed: –Utility studies: two missing –Data for consultant studies: one still to come