PacifiCorp 2007 Integrated Resource Plan (May 30, 2007)

PacifiCorp – 2007 IRPChapter 6 – Modeling and Risk Analysis Approachsearch on the reliability of Class 3 DSM resources to address peak load demand issues, and toimprove the modeling representation of the programs based on the DSM potentials study.Sensitivity Analysis Scenarios for the Capacity Expansion ModuleThe Capacity Expansion Module sensitivity analysis scenarios—designated with the acronymSAS and totaling 16 in number—are intended to supplement the alternative future analysis. 40 Thefocus of these scenarios is to determine optimal portfolios resulting from changes to secondaryvariables and other resource selection factors, with the results to be compared to those for a referencescenario. These sensitivity scenarios are defined with the primary variable values specifiedfor the “Medium Load Growth” scenario (CAF11) except where noted below. The CEMsensitivity scenarios, which are listed in Table 6.3, test the following conditions:• Alternative capacity Planning Reserve Margin levels – low (12%) and high (18%) values.• Deferred carbon dioxide adder implementation – CO 2 costs start accruing in 2016 as opposedto 2012, which is the assumed year of a fully phased-in CO 2 adder.• The impact of a regional transmission project – The regional transmission option consists ofa new 1,500-megawatt line from Wyoming to the SP15 transmission zone in southern California,and a new 1,500-megawatt line from Utah to the NP15 transmission zone in northernCalifornia. (The CEM was not allowed to choose this resource; rather, it was fixed in order todetermine the economic benefits assuming that it is built and PacifiCorp acquires an ownershipshare or transmission rights.)• Determination of the carbon dioxide adder threshold value that affects resource selection;specifically, run the CEM with incrementally higher CO 2 adders to determine at what pointmajor changes in resource selection are made.• Low and high wind project capital costs (see Table 6.4)• Low and high coal commodity prices• Low and high IGCC plant capital costs (see Table 6.4)• Integrated Gasification Combined Cycle technology configurations – constrain the CapacityExpansion Module to select an IGCC plant if not chosen as a resource given expected valuesfor the primary variables (i.e., the “Medium Load Growth”, CAF11). The IGCC plant istested with three configurations: minimum carbon capture provisions, one gasifier, and carbonsequestration included. The scenarios are used to determine the incremental cost impactrelative to an unconstrained resource choice.• An alternative approach for determining the peak system obligation 41• Impact of renewable Production Tax Credit expiration combined with other regulatory developmentsfavorable for wind projects, namely CO 2 regulation and widely-adopted renewableportfolio standards. This scenario uses variable values defined for the “favorable windenvironment” alternative future scenario (CAF07).40 A sensitivity scenario for testing the impact of replacing Klamath Falls hydro units with alternative resources wasexcluded from the list, as it was determined that such analysis was not appropriate for the IRP setting given ongoinglitigation and settlement discussions.41 In its 2004 IRP Acknowledgement Order, the Oregon Public Utility Commission directed PacifiCorp to “evaluatealternatives for determining the expected annual peak demand for determining the planning margin—for example,planning to the average of the eight-hour super-peak period.” (Order No. 06-029, January 23, 2006.)124