2020 De l iverab i l i ty S tudy Repor t

November 5, 2020

SPP Resource Adequacy

Southwest Power Pool, Inc.

REVISION HISTORY

DATE OR VERSION NUMBER

AUTHOR CHANGE DESCRIPTION COMMENTS

10/23/2020 SPP Staff Initial Draft

10/29/2020 SAWG Review

11/5/2020 Initial Posting

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Southwest Power Pool, Inc.

CONTENTS

Revision History...............................................................................................................................i

1. Executive Summary.................................................................................................................5

1.1 Studied Capacity..........................................................................................................5

1.2 Results.........................................................................................................................6

1.3 Acknowledgements.....................................................................................................6

2. Introduction..............................................................................................................................7

2.1. Objective......................................................................................................................7

2.2. Applicability.................................................................................................................7

2.3. Study Process...............................................................................................................7

3. Study Inputs and Assumptions.................................................................................................9

3.1. Software...................................................................................................................... 9

3.2. SPP Balancing Authroity Area......................................................................................9

3.3. Base Models and Topology........................................................................................10

3.4. Generator Grouping...................................................................................................10

3.5. Transfer File...............................................................................................................10

3.6. Monitored and Contingent Elements........................................................................10

3.7. Excluded Contingencies.............................................................................................11

3.8. Other Study Assumptions..........................................................................................11

4. Results....................................................................................................................................12

4.1. 2020 Deliverability Study Results...............................................................................12

4.2. Trending Results........................................................................................................12

4.3. Conclusion................................................................................................................. 16

Appendix D: List of Acronyms.....................................................................................................17

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Southwest Power Pool, Inc.

LIST OF FIGURES

Figure 1: Chart representation of deliverable, committed, and available capacity...........................................................................................................9Figure 2: Regional map indicating the SPP BA boundary...............................11Figure 3: Trending Deliverability Study results for Coal and Natural Gas resources.......................................................................................................15Figure 4: Trending Deliverability Study results for Wind and Solar resources........................................................................................................................16Figure 5: Trending Deliverability Study results for Hydro and Nuclear resources.......................................................................................................16Figure 6: Trending Deliverability Study results for Fuel Oil and Other Fuel resources.......................................................................................................17Figure 7: Trending Deliverability Study results for Agricultural Byproducts and Municipal Solid Waste resources.............................................................17

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Southwest Power Pool, Inc.

LIST OF TABLES

Table 1: SPP max capacity by fuel type...........................................................5Table 2: 2020 Deliverability Study Results by fuel type..................................6Table 3: 2020 Deliverability Study Results by fuel type................................12Table 4: Deliverable Capacity from the previous three studies.....................13

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1. EXECUTIVE SUMMARY

In accordance with Attachment AA1 of the SPP Open Access Transmission Tariff (OATT), Southwest Power Pool (SPP) is required to perform an annual Deliverability Study determining the available Deliverable Capacity of resources registered in the SPP Integrated Marketplace. The Deliverability Study determines how much of each resource’s capacity is deliverable to the SPP Balancing Authority Area, specific delivery points or zones within SPP are not studied. The results of the 2020 Deliverability Study are valid for the upcoming Summer Season (2021) and the subsequent Summer Season (2022). Deliverable Capacity purchases allow a Load Responsible Entity (LRE) to satisfy the Planning Reserve Margin (PRM) portion of its Resource Adequacy Requirement without obtaining firm transmission service.

1.1 STUDIED CAPACITYThe capacity configuration by fuel type for the SPP Balancing Authority (BA) is shown below in Table 1.

Table 1: SPP max capacity by fuel type

Fuel TypeMax Capacity2

(MW)Agricultural Byproducts 7

Coal 22,992Energy Storage 10

Fuel Oil 1,567Hydro 3,428

Municipal Solid Waste 14Natural Gas 36,297

Nuclear 2,061Other Fuel 56

Solar 235Wind 26,623

Total Capacity 93,290

1 Attachment AA (Section 10): https://www.spp.org/documents/58597/attachment%20aa%20tariff.pdf 2 Registered capacity as of September 1, 2020.

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1.2 RESULTSAfter performing the analysis, using TARA software, it was determined the total Deliverable Capacity was 84,495 MW and the deliverability percentage was 90.6% with the assumptions outlined for the study. Table 2 shows the 2020 Deliverability Study Results by fuel type.

Table 2: 2020 Deliverability Study Results by fuel type

Fuel TypeDeliverable

Capacity (MW)Max Capacity

(MW)Percent Deliverable

(Deliverable Capacity /Max Capacity)

Agricultural Byproducts 7 7 100.0%Coal 22,803 22,992 99.2%

Energy Storage 9 10 90.0%Fuel Oil 1,317 1,567 84.0%Hydro 3,073 3,428 89.6%

Municipal Solid Waste 13 14 92.9%Natural Gas 31,140 36,297 85.8%

Nuclear 2,061 2,061 100.0%Other Fuel 50 56 89.3%

Solar 146 235 62.1%Wind 23,876 26,623 89.7%

Total Capacity 84,495 93,290 90.6%

1.3 ACKNOWLEDGEMENTSThe stakeholder review process was an integral part in this study, and SPP staff appreciates the participation and oversight of the Supply Adequacy Working Group (SAWG).

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2. INTRODUCTION

2.1. OBJECTIVE The objective of the annual Deliverability Study is to evaluate and determine the available Deliverable Capacity of resources registered in the SPP Integrated Marketplace to the SPP BA Area.

2.2. APPLICABILITYThe results from the Deliverability Study indicate the available, but not the committed, capacity of a resource. An LRE may enter into a Deliverable Capacity contract with a Generator Owner that has available capacity not already committed.  The Deliverability Study results can only be used to arrange capacity contracts for the Summer Peak Season3.

The Generator Owner will determine how much available capacity a resource has by subtracting the Deliverable Capacity from the already committed capacity, which will determine the amount of available capacity it has for Deliverable Capacity purchases. Figure 1 shows four different examples of how the amount of available capacity can be determined.

Figure 1: Chart representation of deliverable, committed, and available capacity

2.3. STUDY PROCESS The Deliverability Study process begins with staff defining scope assumptions, which are vetted using the SPP stakeholder process. Once the scope is finalized and approved, input data is collected based on the requirements listed in the scope. The data is modeled using the appropriate software along with the assumptions for the study. This study is performed on resources registered in the SPP

3 The Summer Peak Season is defined as June 1 to September 30.

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Integrated Marketplace while incorporating a First Contingency Incremental Transfer Capability (FCITC) transfer limit analysis. Final metric results were presented to the appropriate SPP working groups. The results for each resource was populated in the Engineering Data Submission Tool (EDST) by October 1 so each Generator Owner has access to the results for each of their resources.

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3. STUDY INPUTS AND ASSUMPTIONS

3.1. SOFTWAREThe Deliverability Study utilized the Transmission Adequacy & Reliability Assessment (TARA) software package from PowerGEM©. TARA is a steady-state power flow software tool with modeling capabilities and analytical applications that extend beyond traditional power flow solution. Using linear (DC) and non-linear (AC) power flow calculations, TARA has the capabilities to perform data checking, N-1 reliability analysis, transfer limit calculation, preventive and corrective dispatch, critical facility identification, reactive analysis, outage analysis, model building, and region specific tools for generation deliverability and reserve requirements analysis. The multi-transfer limit function was used to perform the 2020 Deliverability Study.

3.2. SPP BALANCING AUTHROITY AREAThe map in Figure 2 shows the dispatching boundary of the SPP BA Area for the Deliverability Study4.

Figure 2: Regional map indicating the SPP BA boundary

4 Only the eastern interconnect portions were included for simulation purposes, i.e. all facilities and loads east of the DC ties.

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3.3. BASE MODELS AND TOPOLOGYSPP staff and stakeholders develop planning models representing specific system conditions as part of the Integrated Transmission Planning (ITP) process5. Generator Owners submit generator capability data to SPP that reflect the current capability ratings in the planning models. Transmission projects are developed through the ITP process to address reliability needs. Based on system conditions, the ITP Market Powerflow model demonstrates expected transmission system flows under a Security Constrained Economic Dispatch (SCED) similar to the Integrated Marketplace dispatch and is used as the base model for the Deliverability Study. Additional information about the model can be found in the ITP Scope6.

The topology included in the Deliverability Study utilized the 2021 summer season Market Powerflow model. While the 2021 summer season model was not used for the 2020 ITP, the model was built using the ITP model build process.

3.4. GENERATOR GROUPINGEach resource was grouped into plants based on the site and point of interconnection for each resource. A plant’s maximum output is the summation of the maximum output of all resources at the same site. In order to capture reliability constraints caused by simultaneously increasing multiple plants in a localized area, additional analysis was performed in order to group one or more plants together using a methodology based on Power Transfer Distribution Factors (PTDF). Generators that share PTDF impacts greater than 25% on any transmission element in SPP were grouped together. There were 171 resource groups analyzed in the study, which were comprised of 804 registered resources.

A transfer file was created based on the difference between dispatched capacity from the planning model and nameplate capacity of the plant. For example, if a plant with the nameplate capacity of 200 MW were dispatched at 150 MW, the amount for the transfer analysis would be 50 MW. A transfer file was created for all plants in the study.

3.6. MONITORED AND CONTINGENT ELEMENTSThe monitored and contingent elements included all SPP transmission facilities 100kV and above as well as first tier transmission facilities 230kV and above.

Known System Operating Limits (SOLs) 69 kV and above were monitored during the analysis. The SOLs, which are studied in the annual flowgate assessment, were sourced from the most recent book of flowgates.

5 Link to the latest ITP Manual: https://www.spp.org/engineering/transmission-planning/6 Link to the latest ITP process scope: https://www.spp.org/engineering/transmission-planning/

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3.7. EXCLUDED CONTINGENCIESFrom the contingencies in Section 3.6, contingencies reported as invalid in the ITP process were excluded.

3.8. OTHER STUDY ASSUMPTIONS The initial dispatch amount in the base model is assumed automatically

deliverable to the SPP BA Area since the model dispatches around constraints and sets dispatch amounts for each resource.

As generation is uniformly increased for each group of resources, the SPP Balancing Authority Area demand uniformly increases.

A FCITC analysis of each transfer was performed to determine deliverability limits.

A three percent (3%) Transfer Distribution Factor (TDF) threshold was used to analyze constraints impacted by the transfer.

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4. RESULTS

4.1. 2020 DELIVERABILITY STUDY RESULTSAfter performing the analysis, it was determined the total Deliverable Capacity was 84,495 MW and the deliverability percentage was 90.6% using the approved assumptions outlined for the study. The amount of Deliverable Capacity increased from the 2019 Deliverability Study by approximately 1,000 MW due to an increase of wind capacity. However, the overall deliverability percentage decreased from last year’s analysis by approximately 5%. Table 3 shows the 2020 Deliverability Study Results by fuel type. Table 3: 2020 Deliverability Study Results by fuel type

Fuel Type Deliverable Capacity (MW)

Max Capacity (MW)

Percent Deliverable (Deliverable Capacity /Max

Capacity)Agricultural Byproducts 7 7 100.0%

Coal 22,803 22,992 99.2%Energy Storage 9 10 90.0%

Fuel Oil 1,317 1,567 84.0%Hydro 3,073 3,428 89.6%

Municipal Solid Waste 13 14 92.9%Natural Gas 31,140 36,297 85.8%

Nuclear 2,061 2,061 100.0%Other Fuel 50 56 89.3%

Solar 146 235 62.1%Wind 23,876 26,623 89.7%

Total Capacity 84,495 93,290 90.6%

4.2. TRENDING RESULTSThe annual Deliverability Study process began in 2016; therefore, results were trended based on past studies performed. The incremental amount of Deliverable Capacity has been synonymous with the incremental amount of max capacity studied, which is represented in Table 4.

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Table 4: Deliverable Capacity from the previous three studiesDeliverability

StudyMax Capacity

(MW)Deliverable

Capacity (MW)Percent Deliverable (Deliverable

Capacity /Inst. Capacity)

2016 83,334 79,808 95.8%2017 85,496 82,340 96.3%2018 86,747 83,410 96.2%2019 87,884 83,509 95.0%2020 93,290 84,494 90.6%

The following figures display the Deliverable Capacity and percent deliverable results for each study year by fuel type. The deliverable capacity has increased every study year with the increase of installed capacity. Since the 2016 Deliverability Study, the total amount of installed wind capacity has increased 83% (~12,000 MW) while the total amount of coal and nuclear capacity has decreased 14% (~3,700 MW) and 24% (660 MW), respectively.

Figure 3: Trending Deliverability Study results for Coal and Natural Gas resources.

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Figure 4: Trending Deliverability Study results for Wind and Solar resources.

Figure 5: Trending Deliverability Study results for Hydro and Nuclear resources.

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Figure 6: Trending Deliverability Study results for Fuel Oil and Other Fuel resources.

Figure 7: Trending Deliverability Study results for Agricultural Byproducts and Municipal Solid Waste resources

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4.3. CONCLUSIONThe analysis concluded the total Deliverable Capacity was 84,495 MW and the deliverability percentage was 90.6% with the assumptions outlined for the study. The amount of Deliverable Capacity increased from the 2019 Deliverability Study by approximately 1,000 MW due to an increase of wind capacity. However, the overall deliverability percentage decreased from last year’s analysis by approximately 5%.

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APPENDIX D: LIST OF ACRONYMS

BA Balancing AuthorityDC Direct Current EDST Engineering Data Submission ToolFCITC First Contingency Incremental Transfer CapabilityITP Integrated Transmission Planning LOLE Loss of Load Expectation LRE Load Responsible EntityMW MegawattOATT Open Access Transmission Tariff PRM Planning Reserve Margin PTDF Power Transfer Distribution FactorsSAWG Supply Adequacy Working GroupSCED Security Constrained Economic DispatchSOL System Operating Limit SPP Southwest Power PoolTARA Transmission Adequacy & Reliability AssessmentTDF Transfer Distribution Factor

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