PacifiCorp 2007 Integrated Resource Plan (May 30, 2007)

PacifiCorp – 2007 IRPChapter 5 – Resource Optionsstorage. These technologies convert off-peak capacity to on-peak energy and thereby reduce thequantity of required overall capacity installed for peaking needs. The concepts use TAG data andhave been adjusted to account for current construction market conditions. Battery applicationsare typically smaller systems (less than 10 megawatts) which can have the most benefit in asmaller local area. Pumped hydro is dependant on a good site combined with the ability to permitthe facility, a process that can take many years to accomplish. PacifiCorp does not have any specificpumped hydro projects under development. Compressed air energy storage (CAES) can bean attractive means of utilizing intermittent energy. In a CAES plant, off-peak energy is used topressurize an underground cavern. The pressurized air would then feed the power turbine portionof a combustion turbine saving the energy normally used in combustion turbine to compress air.CAES plants operate on a simple cycle basis and therefore displace peaking resources. A CAESplant could be built in conjunction with wind resources to level the production for such an intermittentresource. A CAES plant, whether associated with wind or not, would have to stand on itsown for cost-effectiveness.NuclearAn emissions-free nuclear plant has been included in the supply-side resource options table. Thisoption is based on the TAG database as well as information from a paper prepared by the UraniumInformation Centre Ltd., “The Economics of Nuclear Power,” April 2006. A 600 megawattplant is characterized, utilizing advanced nuclear plant designs. Nuclear power is considered aviable option in the PacifiCorp service territory on or after 2018.DEMAND-SIDE RESOURCESResource Selection CriteriaFor the 2007 IRP, PacifiCorp evaluated and handled each class of DSM based on its characteristicsand current availability. The company presented its proposed DSM resource representationand modeling methodology at a DSM technical workshop held on February 10, 2006, and consideredpublic feedback in developing its final scheme. The following is a summary, by DSMclass, of how the DSM options were selected for evaluation in the IRP.Class 1 Demand-side ManagementTo address Class 1 programs (fully dispatchable or scheduled firm), the company commissionedQuantec LLC to construct proxy supply curves. (See Appendix B for the entire Quantec DSMsupply curve report.) The supply curves targeted PacifiCorp’s existing program expansion opportunities(e.g., air conditioning load control and irrigation load management) and new programopportunities identified as achievable. For modeling purposes, the Class 1 DSM opportunitieswere combined into the following five subcategories:• Subcategory 1 – Fully dispatchable winter programs, such as space heating• Subcategory 2 – Fully dispatchable summer programs, such as air conditioning, water heating,and pool pumps• Subcategory 3 – Fully dispatchable, large commercial and industrial, with a focus on adjustmentof the heating, ventilation, and air conditioning (HVAC) equipment during the topsummer hours• Subcategory 4 – Scheduled firm – irrigation103