Generation and Import Deliverability Baseline Study CAISO Stakeholder Meeting May 9, 2005

Generation and Import Deliverability Baseline Study

CAISO Stakeholder MeetingMay 9, 2005

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Today’s Agenda

• Background and meeting objectives• Review of study methodology, assumptions and

identified issues • Lunch (on your own)• Review of study results • Review of conclusions/recommendations • Discussion of next steps • Status of locational capacity analysis

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Meeting Objectives

• Describe preliminary results and implications

• Describe ISO recommendations for deliverability in this Baseline Study

• Receive stakeholder input on this Preliminary Baseline Study

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The Concept of Deliverability

• Deliverability, for resource adequacy purposes, ensures the output of a generating unit can reach load under peak conditions

• Deliverability is an essential element of the CPUC’s resource adequacy requirement

• Deliverability does NOT ensure dispatch:– Deliverability does not mean 100% congestion

elimination for all load levels

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The Concept of Deliverability(continued)

• Resources considered in deliverability include:

– Existing generators (for aggregate of load)

– Imports

– Generators within transmission-constrained areas

– New generation interconnections

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Deliverability Strawperson

• The ISO’s proposed strawperson deliverability proposal consists of three assessments:

– Deliverability of Generation to the aggregate of load

– Deliverability of Imports

– Deliverability to Load within transmission constrained areas (locational capacity requirement)

• The Baseline study and this presentation focus on the deliverability of generation and imports only

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Overview- How We Got to this Point -

• Spring 2004 - ISO proposes a straw person deliverability methodology to CPUC

• Late 2004 - CPUC approves methodology in principle

• January 2005 - ISO begins baseline study

• January and February 2005 – PTOs provide data to ISO

• May 2005 – ISO publishes preliminary results of baseline study

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Overview(continued)

- The Bottom Line -

• This preliminary study confirms that:– historical summer peak imports levels are deliverable.– most of the existing generating units in the ISO Control Area are

deliverable

• Some transmission upgrades are needed over the next few years to make all existing generating units fully deliverable to load using this methodology

• The ISO intends to recommend that all existing generators be considered deliverable, and the ISO will work with the PTOs to identify and implement the necessary transmission upgrades

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Overview (continued)

Further Steps for Baseline Study

• May, 2005 - ISO receives stakeholder input and conducts further stakeholder meetings/conference calls if necessary

• June, 2005 - ISO completes deliverability analysis, including any adjustments to the methodology determined to be necessary during stakeholder review

• Early July, 2005 - ISO publishes final results of Baseline Deliverability Study

Preliminary Baseline Study for Generation and Imports

Study Assumptions and Identified Issues

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• Part I: Background and Study Methodology

• Part II: Study Assumptions

• Part III: Identified Study Issues

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Deliverability of Generation:Assumptions

• Capacity resources within a given sub-area must be able to be exported to other parts of the Control Area experiencing a resource shortage due to forced generation outages

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Transmission Linesin California

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Power Plants inCalifornia

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Reserve Shortage inCalifornia

* Summer Peak Load* Power Plants Forced out *** SCENARIO 1***

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All generation in Pocket 1 available

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All generation in Pocket 1 available

Forced outages are random and occur

throughout the system

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Generation Pocket Analysis

• The location of units forced out and causing reserve margin shortage in Scenarios 1 and 2 do not significantly change the loadings on constrained transmission lines associated with the generation pocket

• The units forced out in Scenarios 1 and 2 are outside of the generation pocket study area, so their status and dispatch levels, in aggregate, do not significantly impact the study area

• The hundreds of thousands of generation forced outage scenarios can be sufficiently represented by evenly distributing the forced outages across the system

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Deliverability of Generation: Methodology

• A deliverability assessment should be applied to existing and planned generation located in the control area

– This baseline study covers planned generation through 2006

• Developed from PJM Methodology

• Peak load conditions

• Aggregate of generation can be transferred to aggregate of the ISO Control Area Load

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Generation Deliverability Baseline Analysis

• First we need to apply deliverability test to existing system:

– Validate deliverability test methodology and parameters– Identify all overloads– Mitigate overloads

• Once all overloads in baseline analysis are mitigated, then new overloads that are identified (using the same test) can be consistently and equitably assigned to proposed new generation projects

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Overloads identified during the baseline study could be mitigated by:

– Building new or upgrading existing transmission facilities

– Implementing operating solutions (i.e. short term ratings, RAS/SPS)

– Limit capacity to be counted from the portion of existing generation that is deliverable

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Overview of Test Procedure

1. Build power flow base case model

• Create base case generation dispatch

2. Create study areas around each line and transformer and analyze them individually

3. Identify overloaded lines and transformers constraining generation capacity and the units that are constrained

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Elaborating on the Base Case Dispatch

• Dispatching generation in the base case essentially means that we evenly distribute the available generation

– Since all available capacity is needed, it is all dispatched without consideration of cost

• Base case values will also represent approximate dispatch of generation outside of the study areas during the analysis.

• Generation inside of the study areas will be maximized during the study

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Study Areas Are Created Around Each Line and Transformer

• Each transmission line and transformer is analyzed individually• A study area is established for each line and transformer that

includes all generation with a 5% distribution factor or greater on the particular line or transformer

• Capacity generation dispatch inside the study area is maximized to determine the maximum potential loading on the line or transformer.

• Generation outside the study area is proportionally decreased to balance the load and resources

• This process is intended to test the ability of resources inside of the study area to be dispatched at full output when various resources outside of the study area are unavailable

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Gates 500 kV

Morro Bay PP 230 kV

Gates 230 kV

Storey 230 kV

Borden 230 kV

Mc Call 230 kV

Bellota 230 kV

Warnerville 230 kV

Wilson 230 kV

Gregg 230 kV

Los Banos 230 kV

Dos Amigos 230 kV

Moss Landing 230 kV

Coburn 230 kV

Panoche 230 kV

Helms 230 kV

Midway 230 kV

Arco 230 kV

230/115 kV Bank #1

Line outage

Line overload

23%

-16%

10%

8.5%

2%

1.6%

Example Generation Deliverability Test Study Area for Gregg-Borden 230 kV line

DFAX%

Melones 230 kV

8.8%Henrietta 230 kV

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Generation Deliverability Summary

• Baseline analysis identifies all cases where thermal overloads occur with the existing set of facilities

• The same test applied in this baseline analysis will be applied with new generation capacity so all new overloads can be consistently and equitably assigned to proposed new generation projects

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Deliverability of Imports --Assumptions

• California is dependent on imports to satisfy its resource requirements

• Imported resources in the resource plans of all LSEs need to be assessed by the ISO to ensure that they can be simultaneously accommodated on the transmission grid

• When relying on imports to meet reserve margin requirements, LSEs with the assistance of the ISO should demonstrate that their imports are deliverable from the tie point to aggregate load on the ISO System using a deliverability test procedure similar to the generation deliverability test

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Deliverability of Imports and Internal Generation –

Assumptions

• Assessing the deliverability of imports and generation simultaneously will ensure that any interaction between the deliverability of imports and generation is considered

• This can be done by modeling import capacity to be used for resource adequacy planning purposes as the starting point for import assumptions in the internal generation deliverability analysis

• The initial import capacity would be based on historical data during summer peak load and high import conditions.

• Deliverability conflicts between imports and internal generation were expected to be minimal using historical import data

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Deliverability of Imports and Internal Generation –

Summary

• The initial baseline analysis would determine the deliverability of all existing internal generation units and the total amount of imports on a path by path basis

• This preliminary analysis did not identify any deliverability impacts associated with the historical import levels

• Total deliverable import capacity would be allocated to LSEs using a predetermined allocation methodology (to be determined by the CPUC)

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Network model and Generation Capacity Study –

Assumptions

• A network model of the ISO Controlled Grid modeling the year 2006 was used for this study

• Generation Capacity data collected from generation owners was used for this study

– Capacity values as defined in the Resource Adequacy Workshop Report:

• Net Dependable Capacity

• Qualified Capacity

– Capacity values under Summer Peak temperature conditions.

– All units commercially operable by summer 2006 were modeled

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Import, Load and Contingency Study -- Assumptions

• Imports modeled in the base case are based on OASIS import schedule data from 2003 and 2004:– Summer peak load, maximum import

conditions– by branch group– The 2006, 1 in 5 peak load forecast for the ISO Control

Area was modeled in the base case

• All NERC Category B and C contingencies were analyzed while applying the study methodology: – excluding C.3 overlapping contingencies

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Identified Generation Data Issues

1. For some units, conflicting capacity data was provided by the generation owner and the generation power purchasing utility, due to their different interpretations of the Qualifying Capacity definitions in the CPUC’s Resource Adequacy Workshop Report

• The highest capacity value was tested in the base case.

2. Capacity data provided for some units was significantly higher than the capacity data in WECC basecases

• The highest capacity value was tested in the base case

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Identified Generation Data Issues

3. For intermittent generation, Qualifying Capacity data represents an average production over summer peak load hours

• In some cases this average capacity value could be deliverable but production amounts above that average are not deliverable

• In this situation the average capacity amount is not a valid qualified capacity value since it could represent levels of production that would not be deliverable based on the deliverability methodology

• For this study, the capacity data already in the original WECC base case was assumed to be the maximum production during summer peak load hours to ensure that all production values represented by the average capacity would be deliverable

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Identified Line Rating Issues

• Some ratings have recently been entered into the ISO Transmission Register that are lower than the previously provided facility rating

• These new ratings have not been evaluated using traditional transmission assessment methodologies

• Therefore identified deliverability issues associated with facilities that have this type of rating issue should not be attributed to the proposed deliverability methodology


Study Methodology and

Results

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Deliverability Problems

• A deliverability problem is identified by conditions when resources cannot be delivered to load because their outputs cause reliability problems in the transmission system

• Causes of deliverability problems:- Dispatch of resources: Under normal conditions, deliverability

problems may occur from the dispatch of resources

- Dispatch of resources and contingencies: Combined impact from these two factors cause deliverability problems under emergency conditions

• This study looks for potential deliverability problems from a combination of dispatch and contingency scenarios

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Study Methodology

• The study technique is divided into two main parts: 1) Screening process and 2) Verification process

• Screening process searches for potential deliverability problems using linear analysis technique. The main purpose of this process is to minimize the number of scenarios that will be analyzed by verification process

• Then the scenarios that pass the screening process will be analyzed by Verification process to confirm deliverability problems using AC power flow

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Overview of Study Methodology

ScreeningProcess

AC VerificationProcess

All possible scenarios

Scenarios with potentialproblems

Scenarios withdeliverability

problems

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Study Methodology –Screening Process

• Identify potential deliverability problems using linear analysis

• Since it does not require power flow solution for all scenarios This technique speeds up the study process significantly

• Scenarios that are identified by the screening process will be analyzed again with the verification process

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Study Methodology – Verification Process

• Simulates the scenarios identified by the screening process by utilizing a simplified governor power flow

• If a deliverability problem is confirmed, calculate generation capacity reduction that will lower power flow on the overloaded facility below its rating

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Output Report - Example

Resources with DFAX 5% or higher

Monitored Facility

Details of the outage

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26%

24%

21%

39%

DFAX

-3%


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Output ReportThe Output Report assigns deliverability status of each facility into one of the

following categories:

• Fully deliverable: 100% capacity of the resources using this transmission facility could be counted as deliverable for resource adequacy purposes

• Partially deliverable: Without mitigation, a fraction of capacity should be discounted due to deliverability problems

• Non-deliverable: This is an extreme case where the resources substantially contribute to deliverability problems. Without mitigation, no part of the resources utilizing this facility can be counted for resource adequacy purposes under this test

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Study Results –Summary of preliminary deliverability problems

PG&E Service Territory

No Limiting FacilityPCT

OverloadContingency Type

Curtailment (MW)

1 Humboldt Bay-Humboldt 60 kV line #1 108.91 7.512 Eureka - Humboldt Bay 60 kV line #1 101.91 2.19

7.51



Curtailment (MW)

1 Palermo - Colgate 60 kV line #1 152.98Palermo-Colgate 230 kV line #1 Colgate-Rio Oso 230 kV line #1 Colgate PP #1 and #2

C Insufficient*

2 Chicago Park - Higgins 115 kV #1 117.79 89.163 Higgins - Bell 115 kV line #1 100.27 1.374 Drum - Dutch Flat 115 kV #1 117.13 75.39

5 Drum - Dutch Flat 115 kV #1 101.8Atlantic-Goldhill 230 kV line #1 Rio Oso-Goldhill 230 kV line #1

C 7.91

6 East Nicholas - Rio Oso 115 kV line #1 108.1Colgate-Rio Oso 230 kV line #1 Table Mt - Rio Oso 230 kV line #1 Colgate PP #1

C 109.45

210.06Total Curtailment

Total Curtailment

SIERRA

Rio Oso-Atlantic 230 kV line #1 Rio Oso-Goldhill 230 kV line #1

C

HUMBOLDT

Humboldt Bay-Humboldt 60 kV line #2 Humboldt Bay-Humboldt 115 kV line #1

C

*Curtailing the generators alone is not sufficient to mitigate the overloading conditions

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Study ResultsPG&E (cont)



Curtailment (MW)

1 Taft 115/70 kV Bank #2 103.21Midway-Taft 115 kV line #1 and Fellows-Taft 115 kV line #1

C 2.19

2.19



Curtailment (MW)

1 Gregg - Figarden Tap2 230 kV line #1 154.63 716.022 Figarden Tap2 - Ashlan 230 kV line #1 143.11 565.11

716.04



Curtailment (MW)

1 Morro Bay 230/115 kV Bank #6 154.63Morro Bay-Mesa 230 kV line #1 and Morro Bay-Diablo 230 kV line #1

C Insufficient*



Curtailment (MW)

1 Pittsburg-Clayton 115 kV line #1 126.97 Pittsburg-Clayton 115 kV line #3 and #4 C Insufficient*

LOS PADRES

Total Curtailment

DIABLO

Total Curtailment

Gregg-Herndon 230 kV line #1 and #2 C

Total Curtailment

Total Curtailment

FRESNO

KERN

*Curtailing the generators alone is not sufficient to mitigate the overloading conditions

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Study Results

SCE Service Territory

1100 MW

From Name To Name kV cktPCT

OverloadFrom Name To Name kV ckt Type

ALMITOSE BARRE 230 1ALMITOSW LITEHIPE 230 1ALMITOSE CENTER S 230 1ALMITOSW LITEHIPE 230 1LA FRESA REDONDO 230 1LA FRESA REDONDO 230 2LA FRESA REDONDO 230 1LITEHIPE REDONDO 230 1LA FRESA REDONDO 230 2LITEHIPE REDONDO 230 1

Western LA Basin

Limiting Facility Contingency

117

ALMITOSE BARRE 230 1 103

ALMITOSE CENTER S 230 1

LA FRESA REDONDO 230 2

HINSON LITEHIPE 230 1

C

C

119

124

C

C

C

124LA FRESA REDONDO 230 1

Estimated Gen Reduction to alleviate overloads =

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Study Results

SCE (Cont)

20 MW



VICTOR KRAMER 115 1TAP601 KRAMER 115 1VICTOR TAP601 115 1ROADWAY TAP601 115 1

Tehachapi

65 MW



GOLDTOWN TAP 74 66 1LANCSTR GOLDTOWN 66 1


C


115

East of Kramer 115 kV System

ELDORDO MTN PASS 115 1

Estimated Gen Reduction to alleviate overloads = Limiting Facility Contingency

BANTELOPE CALCMENT 66 1

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Study Results

SCE (Cont)

85 MW



LUGO VICTOR 230 2 104 LUGO VICTOR 230 1 BLUGO VICTOR 230 1 104 LUGO VICTOR 230 2 B

LUGO KRAMER 230 1LUGO KRAMER 230 2KRAMER LUZ LSP 230 1KRAMER BLM WEST 230 1

North of Lugo


C106LUGO VICTOR 230 1


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Study Results

SDG&E Service Territory

50 MW



SANLUSRY SANLUSRY 230 1SANLUSRY SANLUSRY 230 2CRSTNTS TALEGATP 69 1JAP MESA TALEGATP 69 1TALEGA TALEGATP 69 1ESCNDIDO EPP 230 1ENCINATP ENCINA 230 1ENCINATP SANLUSRY 230 1ENCINATP ESCNDIDO 230 1

CALAVRTP CANNON 138 1 108 NORTHCTY PENSQTOS 138 1 CBATIQTOS BATIQTP 138 1BATIQTP PENSQTOS 138 1BATIQTP ENCINA 138 1

104

C

C

CCALAVRTP SHADOWR 138 1

1 103

CALAVRTP SHADOWR 138 1 106

Encina-Escondido 138 kV System

Limiting FacilityEstimated Gen Reduction to alleviate overloads =

Contingency

CALAVRTP CANNON 138

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Study Results

SDG&E (Cont)

110 MW



JAMACHA MIGUEL 69 1JAMACHA MIGUEL 69 2MONTGMRY SOUTHBAY 69 1OTAY SOUTHBAY 69 2MONTGYTP SOUTHBAY 69 1

126

C

C

Contingency

CHOLLAS

SOUTHBAY

SPRNGVLY 69 1 101

SWEETWTR 69 1

Estimated Gen Reduction to alleviate overloads = Limiting Facility

South Bay/Border 69 kV System

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Study ResultsSummary of the Deliverability Problems

For the Entire System

PG&E SCE SDG&E Total

Number of overloaded facilities

12 11 4 27

Number of contingencies causing the overloads

9 11 6 26

Total MW Curtailment 10* 170** 160 340

*Note 1: 923 MW of deliverability problems in the PG&E area are related to criteria violations identified in the transmission expansion planning process.

**Note 2: 1100 MW of deliverability problems in the SCE area are related to recent transmission line deratings. The revised line ratings will be reflected in SCE’s 2005 grid planning assessment. Any identified criteria violations will be addressed as part of that process.

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QUESTIONS?


Study Conclusions and Recommendations

***Stakeholder Comments Needed for these Recommendations

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Recommendation:Approve the Deliverability Study Methodology for generation interconnection study purposes and for resource adequacy counting purposes

• No fatal flaws in the Deliverability Study Methodology were identified

• The majority of issues identified by this study are not attributable to the application of the proposed Deliverability Study Methodology

• This study, using the proposed methodology, demonstrates that historical summer peak imports and almost all of the existing generation are deliverable

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Recommendation:Identified issues should be investigated further by

PTOs

• The issues identified by this study should be investigated and resolved by the PTOs

• Alternatives for resolution include:– Building new or upgrading existing transmission

facilities

– Implementing operating solutions (i.e. short term ratings, RAS/SPS)

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Recommendation:Existing units and imports should be considered

deliverable

• During an interim period, including but not limited to the study year 2006, all generation should be considered to be fully deliverable

• By a date to be determined, any deliverability issues from this baseline study that affect existing units and imports should be resolved by the PTOs

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Recommendation:ISO with PTO support should perform additional

baseline study

• A Phase II baseline study needs to be performed by the ISO with PTO support to include all new generation projects that have approved interconnection studies and operating dates after 2006 to establish the Deliverability of these projects

• The ISO should review with stakeholders a planned schedule for performing this additional baseline study

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Next StepsProposed Action for Finalizing

Phase I Baseline Study• May 23, 2005 - ISO receives written stakeholder

comments• Early June – ISO conducts further stakeholder

meetings/conference calls if necessary• June, 2005 - ISO completes deliverability analysis,

including any adjustments to the methodology determined to be necessary during stakeholder review. ISO publishes final results of Phase I Baseline Deliverability Study

• Early July, 2005 - Begin Phase II Baseline Deliverability Study

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Status of Locational Capacity Analysis

• ISO presented Locational Capacity Requirement methodology/criteria at CPUC workshops late 2004

• Three on-going processes are inter-related– Resource adequacy– Deliverability– Locational capacity requirement

• Present plans are that a transition from RMR to Local Capacity will need to occur in 2006

– ISO RMR analysis currently underway with results presented in May 2005– ISO will re-study the system utilizing the proposed Locational Capacity

methodology/criteria with results presented in June 2005

• ISO is working towards all three processes coming together in July 2005

Generation and Import Deliverability Baseline Study CAISO Stakeholder Meeting May 9, 2005

Documents

preliminary study

deliverability analysis

study methodologypart

study assumptionspart

methodologythe iso

baseline studymay

baseline studyjanuary

imports study assumptions