PacifiCorp 2007 Integrated Resource Plan (May 30, 2007)

PacifiCorp – 2007 IRPChapter 7 – Modeling andTable 7.16 outlines the specifications for the 12 risk analysis portfolios (labeled RA1 throughRA12), and presents the design rationale for each.The CEM scenario definitions for the risk analysis portfolios include the “medium” forecast valuesfor CO 2 costs, gas/electricity prices, load growth, RPS generation requirements, productiontax credit availability, and DSM potential. Nevertheless, the risk analysis portfolios emulatemany of the other scenario conditions modeled for the alternative future studies. For example,RA6, which entails removal of pulverized coal as an option, is representative of the coal resourceoutcome of the three alternative future scenarios based on high coal costs and low gas costs(CAF04, CAF05, and CAF06).Table 7.16 – Risk Analysis Portfolio Descriptions (Group 1)ID Description Design RationaleRA1 “Medium” alternative future portfolio, with wind,DSM, and CHP at fixed levels and front officetransactions capped at quantities assumed for the2004 IRPother 11 portfolios.RA2RA3RA4RA5RA6RA7RA1 with front office transactions removed as aresource option from 2012 onward (long-termasset-based portfolio)RA1 with an additional 600 MW of wind addedinto the portfolioRA2 with 12% planning reserve margin and frontoffice transactions removed as a resource optionfrom 2012 onward (long-term asset-based portfolio)RA2 with the model constrained to select a secondUtah pulverized coal plant in 2013 and aneast-side IGCC in 2014. Front office transactionsare removed as a resource option from 2012onward (long-term asset-based portfolio)RA1 with pulverized coal removed as a resourceoptionRA2 with 600 MW of additional wind as in RA3and front office transactions removed as a resourceoption from 2012 onward (long-termasset-based portfolio)By virtue of having the fewest constraints on resourcechoice, it serves as a performance benchmarkand starting point for development of theTests the strategy of eliminating the use of shorttermmarket purchases (front office transactions)to meet long-term resource needs, and therebyreduce exposure to electricity market price risk.Tests the strategy of using incremental amounts ofwind to reduce CO 2 , fuel, and market price risks.Represents a variant of the “long-term assetbased”portfolio (RA2), but with the lower planningreserve margin to determine the associatedcost/risk tradeoff.Tests the relative economics and risk of buildingcoal early as a hedge against gas and electricitymarket price risk; the IGCC plant replaces an eastsidegas plant.Tests the strategy of reducing CO 2 cost risks, aswell as testing the risk impact of relying on highervariable cost, shorter lead-time resources untilIGCC is commercially ready (i.e., gas-fired generationand market purchases).Tests additional wind in combination with theconstruction pattern resulting from limiting frontoffice transactions.RA8 RA1 with a 12% planning reserve margin Tests the medium alternative future portfolio(RA1) with the lower 12% planning reserve margin.RA9RA8 with the model restricted to select WyomingIGCC plants in 2013 and 2016Tests an IGCC-intensive portfolio at the lowerplanning reserve margin level, assuming that thetechnology is commercially mature enough toacquire by 2013.RA10 RA9 with a 15% planning reserve margin Creates a version of RA9 that parallels others withthe higher 15% planning reserve margin. Recommendedby an IRP public stakeholder at the October31, IRP public meeting.159