Sixth Northwest Conservation & Electric Power Plan Proposed Heavy-duty Combustion Turbine Planning Assumptions Jeff King Northwest Power and Conservation Council Portland, OR July 17, 2008

2 Reference plant Twin 85 MW (nominal) natural gas-fired gas turbine generators and ancillary equipment, control building and switchyard. Inlet air evaporative cooling. Low-NOx combustors and water injection for NOx control. Characteristics generally based on GE Frame 7EA.

July 17, Heavy-duty GT applications:  Energy generation  Cogeneration (requires heat recovery & integration equipment)  Regulating reserve (requires AGC)  Load-following (requires AGC)  Spinning reserve (requires AGC)  Non-spinning reserve  Replacement reserve  Voltage control (VAR support) (requires clutch)  Black start (requires auxilliary diesel generator)  Local emergency service Status: Commercially mature

July 17, H. D. GT operating characteristics I 5 th PlanProposed Base rating (net ISO MW, lifecycle average) 2 80 MW/unit 2 82 MW/unit ISO rating less 2% plant losses, less 2% degradation Rating at reference PNW locations PNW Westside (200’) PNW Eastside (700’) S. ID (3000’) E. MT (5500’) Minimum load (% rated power)25%Same Ramp rate (%/hr)>100%SameCold start to min. load < min Minimum run time (hr)1 hour< 1 hr Minimum down time (hr)1 hour< 1 hr

July 17, H. D. GT operating characteristics II 5 th PlanProposed Scheduled outage factor7% (26 day/yr average) ReviewAssume hours-dependent or starts-dependent maintenance in PNW? Need H.D. GT maintenance schedule to review. Equivalent forced outage rate7%??NERA is 3.7%. Review GADS Mean time between failures--???New parameter for PRM; will review GADS Mean time to repair51 hrSameGADS value ca: Will review GADS Heat rate (HHV, full load, lifecycle ave) 10,500 Btu/kWh11,800 Btu/kWhGTW nominal + 2.1% ave. lifecycle degradation. Vintage heat rate improvement- 0.5%/yr averageSame5% learning rate Service life30 yearsSame

July 17, H. D. GT Costs (2006 dollar values) 5 th PlanProposed Overnight construction cost$700/kW$430/kWSee following slides Vintage capital cost escalation-0.5%/yrDiscussion to follow Non-fuel Fixed O&M$7.00/kW/yrDiscussion to follow Exclusive of property taxes & insurance Non-fuel Variable O&M$4.60/MWhDiscussion to follow Startup Cost--Fuel for 20 min operation at min load Gas Turbine Handbook Shutdown Cost--Fuel for 30 min operation at min load Gas Turbine Handbook Transmission CostNoneSameAssumed to be located at load center Transmission LossesNoneSameAssumed to be located at load center

July 17, Heavy-duty GT construction cost analysis NPCC database contains reported construction cost for 7 WECC plants comprising 8 units, Normalized capital cost using MICROFIN Assume cost is vintaged as of beginning of construction (YOL - 1) 2006 dollar values "Overnight" construction + development cost Nominal ISO capacity Unit-weighted (we need an average cost value for a potential mix of plant configurations)

July 17, Normalized heavy-duty GT cost Proposed 2008 cost: $430/kW "Overnight", 2006$, 2009 service

July 17, Schedule, Cash Flows & Option phases Portfolio Risk model development phases > Development“Optional” Construction “Committed Construction” MilestonesFeasibility study through completion of permitting Notice to proceed to major equipment foundations complete Accept major equipment to commercial operation Time to complete18 mo12 mo(3) 6 mo Cash expended2 %93 %5 % Cost to suspend ($/kW)Negligible-- Cost to hold ($/kW/yr)$ 1.16 ($95,000/yr)-- Maximum hold time60 mo -- Cost of termination following suspension ($/kW) Negligible-- Cost of immediate termination ($/kW) Negligible--

July 17, Environmental 5 th PlanProposed Particulates--Values from recent permit? NPCC does not use & few if any requests SO2 -- ''NPCC does not use & few if any requests NOx -- ''NPCC does not use & few if any requests CO--''NPCC does not use & few if any requests Hydrocarbons/VOC--''NPCC does not use & few if any requests CO2 – Embedded--??? CO2 – Direct operation614 T/GWh690 T/GWhRevised heat rate CO2 – Indirect operation--???