SPP.org 1

Final Report: Reliability and Economic Assessments Stakeholder Meeting December 1, 2008 Austin, TX

SPP.org 3 Activities Completed Since Last Meeting Reliability Assessment  Finalize results for SPP QPR option  Tie back Study for ERCOT QPR option  Stability Analysis for SPP QPR option Economic Assessment  Economic projects identified  Cost/Benefit Analysis for Status Quo and Integrated case

SPP.org 4 Transmission Upgrades: Reliability Upgrades and Economic Upgrades

SPP.org 5 Reliability Study Cases Contingency analysis (N-1) for SPP- ETI system  More stringent reliability criteria in Western Region (N-1, G-1)  Monitored 69 kV and above Several potential thermal and voltage violations found SPP examined a set of reliability upgrades to mitigate these violations  Substation work at Orange County  Reconductor eight 138 kV lines in ETI area  Reconductor five 69 kV lines in ETI area High level planning estimate of projects required to meet SPP Criteria is $105 M COTTONWOOD IN EASTERN INTERCONNECTION Projects to meet SPP Criteria  New Orange County Substation work ($50 M)  138 kV and 69 kV Upgrades ($55 M) Planned Known Projects  ETI Proposed Projects for 2012  Local Reliability projects for Western Region  Transmission Reliability projects from the 2007 approved STEP Plan  ETI Transmission Construction Plan

SPP.org 6 Tie Back Study Objective of this study to evaluate reliability of SPP system under ERCOT QPR option Most of the tie-lines across LA-TX removed and loop backed DC ties at two locations considered  Hartburg (830 MW and 250 MW)  Quarry, Near Crockett (150 MW and 50 MW)

SPP.org 7 Potential ETI-ERCOT Disconnection Points Quarry Newton Bulk Leach Hartburg Sabine To Big Three, Hollywood, Toomey Orange Bon Wier DETAIL 1 DETAIL 2

SPP.org 8 DETAIL 1

SPP.org 9 DETAIL 2

SPP.org 10 ETEC System Disconnection Points X Pineland- Bronson

SPP.org 11 Tie Back Study : Study Results SPP Area were examined based on N-1 contingency analysis using SPP Criteria Four Key Transmission Projects were identified by SPP staff to meet the SPP reliability criteria for ERCOT QPR option  Upgrade Broken Bow – Bethel 138kV line  Upgrade Fisher Transformer (138/115kV)  Upgrade Toledo Bend – Hemphill 138kV Line  Acadiana Projects

SPP.org 12 Estimated Cost for SPP Members under ERCOT QPR option Direction is from ETI to SPP Hartburg DC Tie (830 MW)(250 MW) Quarry DC Tie 150 MW $25 Million$31 Million 50 MW $25 Million$61 Million

SPP.org 13 Stability Assessment Objective of this study is to evaluate stability of ETI under SPP QPR and ERCOT QPR options A consultant (Powertech) is performing this study Transient and Voltage Stability analyses being performed using Entergy and SPP Stability Criteria ETI system will be tested under various fault scenarios and transfers into ETI using projects identified for SPP QPR option

SPP.org 14 Stability Assessment : Cont. Stability study models are prepared jointly by SPP and ETI staff and sent to Powertech Simulated critical N-1, G-1, and N-G-1 contingencies in ETI first-tier areas (both electrical and geographical areas in SPP and rest of Entergy) Preliminary results indicated no significant issues in ETI system  Results indicate that RMR Requirements can be reduced The final results are expected in first quarter of 2009

SPP.org 15 Economic Upgrades Two Projects included as Economic Upgrades  Mt. Olive to Hartsburg series capacitor ($10 M)  Increased rating to 1,450 MW thus reducing significant constrained hours  Weber-Richard 500 kV line ($229 M)  Helped reduced congestion in Cottonwood area and RMR need in Sabine area along with other reliability upgrades

SPP.org 16 Cost allocation of ETI Reliability projects Reliability projects are required solely to integrate ETI into SPP SPP policy is to allocate these costs to the local zone  Similar to current discussion with Nebraska entities  Consistent with treatment with Pre Base Plan funding ETI Benefits compared to full cost of Reliability Projects ($105 M)

SPP.org 17 Cost allocation of ETI Economic Projects ETI Benefits compared to full cost of Economic Projects ($239 M) Economic Upgrades may be fully or partially funded by SPP pursuant to their Tariff provisions (i.e. Balanced Portfolio)

SPP.org 18 Economic Assessment

SPP.org 19 Key Market Assumptions – Status Quo Model SPP Market Assumptions  SPP modeled as Day 2 Market planned by SPP Cost Benefit Task Force  System wide unit commitment  System wide treatment of spinning reserve requirements  Security Constrained Unit Commitment and Economic Dispatch  SPP operates as a Single Balancing Authority Entergy (including ETI) Operating Assumptions  System wide unit commitment  Security Constrained Economic Dispatch  Reserve Requirements set and met on Entergy System wide basis  ETI RMR Requirement consistent with historical operation to address local voltage constraints  ETI and Entergy generation output consistent with historical operations Hurdle rates between SPP / other Regions and Entergy / other Regions  Dispatch hurdle 7 $/MWh (Entergy/SPP hurdle rate $14/MWh)  Commitment hurdle 25 $/MWh  Consistent with SPP Future Market Design Study assumptions

SPP.org 20 Key Market Assumptions – ETI/SPP Integrated Model SPP Market Assumptions same as Status Quo model ETI is a Member of SPP ETI RMR Requirements are reduced due to Reliability and Economic Transmission upgrades  Consistent with preliminary stability analysis results  Thermal constraints continue to be identified via Security Constrained Economic Dispatch (transmission system now includes all Reliability Projects and Economic Projects) Hurdle rates same as Status Quo except no hurdle rate between SPP and ETI

SPP.org 21 Benefit Metric – ETI Adjusted Production Cost Same Benefit metric being used by the SPP Cost Benefit Task Force in the Future Market Design Study Adjusted Production Cost for ETI  Generation Total Variable Cost  + Purchase Cost at ETI Load-Hub Rate  – Sales Revenue at ETI Generation-Hub Rate

SPP.org 22 ETI Benefits

SPP.org Benefits to ETI

SPP.org 24 Discussion of Findings - ETI Cottonwood in Eastern Interconnection (EIC)  ETI Generation Cost reduced by $404 M, purchase costs increased by $237 M and sales revenue was reduced by $64 M, resulting in an overall benefit of $103 M.  Based on an 18% carrying charge rate for Transmission Investment, this $103 M would support about $570 M in transmission investment  Proposed total cost of Reliability and Economic Upgrades is about $344 M  Benefit to Cost Ratio is 1.63  Includes $5 M in ROA implementation cost Cottonwood in ERCOT  Benefits reduced due to loss of Cottonwood generation  $90 M in benefits would support about $500 M in Transmission Investment  Benefit to Cost Ratio drops slightly to 1.43  Includes $5M in ROA implementation costs

SPP.org 25 ETI Benefits Sensitivity – NO RMR Requirements

SPP.org Benefits to ETI if RMR Requirement Removed

SPP.org 27 Discussion of Findings – No RMR Requirement Benefits increase to $163 M, creating an incremental benefit of about $60 M This $60 M in incremental benefits would support about $333 M in potential projects  Based on 18% carrying charge rate on transmission investment  Potential for future Economic Upgrade  There is no guarantee that this level of investment would be sufficient to relieve the remaining RMR requirements

SPP.org 28 Questions?

SPP.org 29 Detail Slides

SPP.org ETI Benefits Breakdown

SPP.org ETI Benefits Breakdown

SPP.org 32 Mak Nagle Manager, Technical Studies & Modeling (501) Wayne Camp Accenture