PacifiCorp 2007 Integrated Resource Plan (May 30, 2007)

PacifiCorp – 2007 IRPChapter 4 – Resource Needs Assessmentsources account for roughly two-thirds of the firm capacity available in the PacifiCorp system.● Hydro – This includes all hydroelectric generation resources operated in the PacifiCorp systemas well as a number of contracts providing capacity and energy from various counterparties.The capacity balance counts these resources by the maximum capability that is sustainablefor one hour at time of system peak. The energy associated with critical level streamflow is estimated and shaped by the hydroelectric dispatch from the Vista Decision SupportSystem model. Over 90 percent of the hydroelectric capacity is situated on the west side ofthe PacifiCorp system.● Demand-side Management (DSM) – There are about 160 megawatts of Class 1 demandsidemanagement programs included as existing resources. Both the capacity balance and theenergy balance count DSM programs by program capacity. DSM resources directly curtailload and thus planning reserves are not held for them.● Renewable – This category contains two geothermal plants (the existing Blundell plant withthe bottoming-cycle upgrade, and the Cove Fort project), eight existing wind projects andthree planned wind projects from the MEHC commitments. The capacity balance counts thegeothermal plants by the maximum dependable capability while the energy balance countsthe maximum dependable capability after forced outages. Project-specific capacity credits forthe wind resources were determined in a wind capacity planning contribution study (AppendixJ). Wind energy is counted according to hourly generation data used to model the projects.● Purchase – This includes all of the major contracts for purchases of firm capacity and energyin the PacifiCorp system. The capacity balance counts these by the maximum contract availabilityat time of system peak. The energy balance counts the optimum model dispatch. Purchasesare considered firm and thus planning reserves are not held for them.● Qualifying Facilities (QF) – All Qualifying Facilities that provide capacity and energy areincluded in this category. Like other power purchases, the capacity balance counts them atmaximum system peak availability and the energy balance counts them by optimum modeldispatch. It is assumed that all Qualifying Facility agreements will stay in place for the entireduration of the 20-year planning period. It should be noted that three of the Qualifying Facilityresources (Kennecott, Tesoro and US Magnesium) are considered non-firm and thus donot contribute to capacity planning.● Interruptible – There are three east-side load curtailment contracts in this category. Theseagreements with Monsanto, MagCorp and Nucor provide about 300 megawatts of load interruptioncapability at time of system peak. Both the capacity balance and energy balancecount these resources at the level of full load interruption on the executed hours. Interruptibleresources directly curtail load and thus planning reserves are not held for them.77