PacifiCorp 2007 Integrated Resource Plan (May 30, 2007)

PacifiCorp – 2007 IRPChapter 7 – Modeling and• The Wyoming SCPC plants were moved up a year, and the large and small Utah SCPCsswitched places: the large 600-megawatt unit moved from 2018 to 2012, while the small 340-megawatt unit moved from 2012 to 2018. (The coal price change adversely affected the economicsof the small Utah SCPC unit to a greater degree than for the large Utah SCPC unit).The timing change of the coal plants resulted in removal of a west SCCT (332 megawatts)and 300 megawatts of wind (42-megawatt capacity contribution)• The PVRR increased by $375 million• Front office transaction increased by an average annual 44 megawatts, while DSM decreasesby 61 megawattsLow and high IGCC capital costLowering the IGCC capital cost had the following effects relative to the base case portfolio:• The CEM added an east IGCC (497 megawatts), and moved up the 200-megawatt westIGCC from 2017 to 2016• The CEM removed 700 megawatts of wind (119-megawatt capacity contribution), and aSCCT (302 megawatts)• The PVRR decreased by $46 million• Front office transactions increased by an average annual 13 megawattsRaising the IGCC capital cost had the following effects relative to the base case portfolio:• The west IGCC is deferred from 2017 to 2018, which increases front office transactions byan average annual 46 megawatts and raises PVRR by $54 millionImpact of switching from an IGCC with a spare gasifier to one with a single gasifierThis change reduced PVRR by $4 million. Resource impacts included switching the location of aSCCT from the west location to the east location in 2012, reducing wind by 200 megawatts (32-megawatt capacity contribution), and reducing front office transactions by an average annual 87megawatts.Cost impact of building an IGCC with carbon sequestrationReplacing a carbon-capture-ready IGCC with one that has carbon sequestration increased PVRRby $541 million. The IGCC replacement resulted in minor resource selection impacts; namely,Class 1 DSM increased by 48 megawatts, and front office transactions increased by an averageannual 19 megawatts.Plan to the average of the eight-hour super-peak periodRelative to the base case portfolio, CAF11, planning to the average of the eight-hour super-peakperiod decreases PVRR by $194 million. The resource impacts include: removal of a SCCT (302megawatts), a decrease in wind capacity by 100 megawatts, and a reduction in front office transactions(103 megawatts on an average annual basis). DSM was unaffected.Favorable wind development environment combined with expiration of the renewable productiontax credit (PTC)Comparing the portfolio PVRR for CAF07 and SAS16 indicates the impact of not renewing thePTC after 2008. The impact was found to be an additional $1.7 billion. Removing the PTC also150