PacifiCorp 2007 Integrated Resource Plan (May 30, 2007)

PacifiCorp – 2007 IRPChapter 7 – Modeling andTable 7.49 – Capacity Additions for the Initial CEM GHG Emissions Performance StandardPortfolioCumulative NameplateCapacity by Period (MW)Resource 2007-2016 2007-2026Gas - CCCT 1,507 6,410Renewables 1,900 3,100DSM 137 156IGCC with CCS - -As noted above, the CEM was not constrained to select certain resource amounts in certain yearsor areas. One consequence of this model set-up is that the resulting CEM portfolio does not reflectan investment schedule that is advantageous from a stochastic cost and risk standpoint. Anotherconsequence is that the model’s wind investment pattern differs significantly from whatwas identified in PacifiCorp’s preferred portfolio. For example, the model did not recognizegeographical RPS requirements in placing renewable resources; all wind resources were added inthe east side until 2018. Additionally, the CEM included more renewables in 2007 than the preferredportfolio (700 megawatts versus 400 megawatts in the preferred portfolio), which is notpractical from a procurement perspective.To address these two issues, PacifiCorp first subjected this portfolio to stochastic simulation tocreate baseline stochastic results. Then, the CEM was executed again after applying resourceconstraints to the portfolio. These constraints include (1) limiting renewables to 300 megawattsin 2007 66 , (2) adding an east-side CCCT in 2011 to replace a portion of front office transactions,and (3) fixing the east-side CCCT resource selected in 2011. The resulting CEM portfolio wassimulated with the PaR model, and stochastic results compared against those of the originalCEM portfolio. These resource constraints reduced stochastic mean PVRR by $144 million, riskexposure by $671 million, and upper-tail risk by $816 million. Table 7.50 shows the resourceadditions for the final GHG emission performance standard portfolio from 2007 through 2026.As with the other risk analysis portfolios, load growth and capacity reserve requirements are metwith CCCT growth stations after 2018.Stochastic Cost and Risk ResultsTable 7.51 provides the stochastic cost and risk results for the GHG emission performance standardportfolio by CO 2 cost adder case. Results are shown for both the CO 2 tax and cap-and-tradecompliance scenarios. Figures 7.37 through 7.39 show the cost-versus-risk trade-off of the portfolioin relation to the other Group 2 risk analysis portfolios assuming the CO 2 cap-and-tradescenario. Figure 7.37 is a scatter plot of the cost and risk measures based on the average of thefive CO 2 adder cases, while Figures 7.38 and 7.39 show the cost and risk results for the $0 and$61 CO 2 adder cases, respectively.66 The remainder of the renewables investment schedule was not altered in order to minimize manual portfoliochanges.214