PacifiCorp 2007 Integrated Resource Plan (May 30, 2007)

PacifiCorp – 2007 IRPChapter 7 – Modeling andselected in 2012. Restricting the model to choose only CCCTs resulted in just one east CCCTselected in 2012. (This is in addition to the west CCCT selected in 2012.)● Timing of resource acquisition to address expiration of the BPA peak contract – Removingthe BPA contract in 2011 (as opposed to 2012) had no effect on the timing of thewest CCCT assuming unlimited availability of front office transactions in 2011.● Alternative planning reserve margins – Under a 12% planning reserve margin, allowingthe model to choose its own gas resources resulted in two SCCT frames selected in 2012 –one in the east and one in the west; this is in addition to the west CCCT selected in 2012.Under a 15% planning reserve margin with no gas resource option restrictions, the CEMportfolio solution included about 200 megawatts of additional gas resources by 2016; eastSCCT frames were selected in 2010 and 2012 in addition to an east CCCT in 2012.Based on these results, PacifiCorp developed five portfolios for stochastic simulation. Theseportfolios are intended to compare CCCTs against reliance on the market to meet new forecastedloads under alternative planning reserve margin targets (12% and 15%). Combined cycle plantswere chosen as the proxy gas-fired resource type for two reasons. First, the PaR stochastic simulationcaptures extrinsic (or optionality) value of a resource, while the CEM does not. A CCCT isexpected to have a lower PVRR impact than a non-base-load gas resource with all else held constant.Second, the larger CCCT minimizes the number of gas resources added in a single year.In addition, all five risk analysis portfolios have a west CCCT added in 2011 to ensure that aresource is available to meet west-side load by August 2011. Finally, the amount of annual frontoffice transactions needed to balance the system is determined by CEM; no caps are placed onthe resources.Table 7.30 outlines the specifications for the five risk analysis portfolios (labeled RA13 throughRA17), and presents the design rationale and common features for each.Table 7.30 – Risk Analysis Portfolio Descriptions (Group 2)ID Description Design Rationale FeaturesRA13 An updated “Base Case”resource proposal that mirrorsthe original PacifiCorpBusiness Plan’s base loadThis portfolio serves as thereference portfolio forcomparison with the otherrisk analysis portfolios. It• Based on the revised load forecast(March 2007)• Wind investment schedule assumedfor original Business Planresources. This portfolio, based reflects a coal- and• All portfolios use the sameon a 12% planning reserve market- intensive resource transmission investment schedulemargin, includes fourstrategy.supercritical pulverized coalresources: the small UtahSCPC (2012), the WyomingSCPC (2014), the large UtahSCPC (2017), and the secondWyoming SCPC (2018).182