Rocky Mountain States Sub-Regional Transmission Study December 9, 2003 Generation Additions Strawman

RMATS 2 2 Presentation Objective  Present Fuel Price Assumptions  Present Wind and Planning Margin Assumptions  Present Strawman for developing generation alternatives for 2013 Cases Guidelines Generation Grouping Alternatives  Obtain Steering Committee Approval of Assumptions and Strawman

RMATS Simulation $4/$5 Gas Sensitivity 2013 Simulation High/Medium Gas Sensitivity 5 Gas/Hydro Sensitivities 2 Alternatives Export Top Alternatives “New Generation” 1. Financially Sound & 1/2 committed 2. Comes w/Transmission Cases Included in Study High Load Sensitivity (2013) 2 Alternatives Serve Load Phase 2 (Alternatives) Phase 1 (Base Case)

RMATS 4 2  Agreed to The First 2008 Base will set the US Average Wellhead price at $4.00/MMBtu The Second 2008 Base Case will use $5.00/MMBtu. The subcommittee will evaluate the new EIA forecast when it is released on December 16th The basis differential will be set to match the 5th Northwest Conservation & Electric Power Plan 2008 Henry Hub Gas Future Price $4.70/MMBtu range (nominal $)  Need to Address The risk of increased costs due to CO2: $8/ton, $25/ton, ? Future environmental regulations? Others? RAWG-Gas Prices Subcommittee

RMATS 5 2 Gas Prices  All basis shown compared to US Wellhead w/fuel use  All values shown in nominal $/MMBtu

RMATS 6 2  FERC indicated that resource adequacy will be left up to the states and/or regions Operating requirements vary by control area (NERC mandated)  RAWG participants agreed on using 15% (earlier SMD target) Planning Margin

RMATS 7 2 “New Resources”  “New” resources for 2008 Includes plants sponsored by organizations that have the ability to secure the proper permits, financing and construction. More than half of the generation should be subscribed Must have associated transmission All added plants are planned to be online by 2006

RMATS 8 2 “New Resources”  Nebo 147 MW- Gas (Utah)  Currant Cr 525 MW- Gas (Utah)  Springerville Expansion 400 MW Coal (Arizona)  Bennett Mt 167MW- Gas (Idaho)  Pleasant Valley 144MW- Wind (Wyo)

RMATS 9 2 Renewable Resources 2008 Wind

RMATS 10 2 Wind Modeling NREL Will Provide Clarification on:  Capacity Credit VS Effective Load Carrying Capability  Capacity Factor VS Capacity Credit  Capacity Credit: 20% or ?? (use 20% to determine alternatives and look to NREL for improvement)

RMATS 11 2 Strawman for 2013 Gen. Alternatives Guidelines  Each new generation project should be modeled in at least one- generation alternative either as an individual project or as a part of a coherent group. Generation may be aggregated into coherent groups by fuel type that is within a geographic area. If it becomes necessary to prorate generation capacity it would be reduced as a group and no individual project would be required to withdraw from the alternative.  Wind generation would be considered as having a contribution toward capacity as 20% of the nameplate rating. (will be modified based on NREL study results)  The total capacity within an alternative generation group would be generally equal to the load increase (from 2008) plus 15% planning reserve.  A 2013 base case will not be created but all the alternatives will reflect a 2013 time frame and will be compared to the 2008 base case.

RMATS 12 2 Strawman for 2013 Gen. Alternatives Groupings  Generation equal to one times the RMATS Load Growth from 2008 to 2013 (3,500 MW) plus reserves. Generation additions will be based on the IRPs of RM area utilities and the RMATS new generation list (as revised).  Generation equal to one times the RMATS Load Growth from 2008 to 2013 (3,500 MW) plus reserves. Generation additions will be based on a coordinated look at the IRPs of RM area utilities and the RMATS new generation list (as revised).  Generation equal to two times the RMATS Load Growth from 2008 to 2013 (7,000 MW) plus reserves. Generation additions will be based on the RMATS new generation list (as revised) and judgments by the RAWG. (an export case)  Generation equal to three times the RMATS Load Growth from 2008 to 2013 (10,500 MW) plus reserves. Generation additions will be based on the RMATS new generation list (as revised) and judgments by the RAWG. (an export case)