Draft TEPPC 2016 Study Program€¦  · Web viewThis document presents and discusses details of the 2016 Transmission Expansion Planning Policy Committee (TEPPC) Study Program. TEPPC

Draft TEPPC 2016 Study Program

2016 TEPPC Study ProgramDRAFT for TAS Review

Studies Work Group

April 15, 2016

155 North 400 West, Suite 200

Salt Lake City, Utah 84103-1114

2016 TEPPC Study Program5

Western Electricity Coordinating Council

Table of ContentsIntroduction2Transmission Planning and the Study Program3Purpose of Transmission Planning3Relevance of TEPPC Planning Process to Regional Planning Efforts4TEPPC Study Program Development4Lessons Learned from Previous Study Cycles7Other Study Activities7Types of Study Cases7Elements and Themes of this Study Program10Study Consideration Criteria11The following criteria were used as guidance in soliciting the 10-year and 20-year studies.11General Study Themes11Focus areas for 2016 TEPPC Study Program13Special Spatial Data Assessment Project:14Appendix A – 2016 TEPPC Study Program Cycle15Appendix B – 2016 TEPPC Study Program16Common Case, Reference Case and Sensitivities:17Appendix B - Glossary of TEPPC Terminology23Appendix C - TEPPC 2015 Study Program Study Case Scoping Form27

Introduction

This document presents and discusses details of the 2016 Transmission Expansion Planning Policy Committee (TEPPC) Study Program. TEPPC is tasked with conducting an annual transmission system study program (Study Program) as a component of WECC’s regional transmission planning process in accordance with WECC’s broader mission to assess the reliability impacts of the Western Interconnection under varying economic, technological and regulatory (policy) conditions. . The 2016 TEPPC Study Program is intended to guide and improve economic and operational analyses and modeling of the Western Interconnection through transmission utilization and planning studies. The studies are requested by a diverse range of stakeholders – Load Serving Entities, Transmission Planners (TPs), Transmission Owners (TOs), public interest stakeholders, western state agencies, and regulatory staff. The TEPPC Study Program also informs the planning obligations of regional planning groups across the Western Interconnection and not limited to, entities obligated to comply with FERC Order 890 and 1000 planning tasks.

The 2016 Study Program has been prepared under the provisions of the Interim TEPPC Planning Protocol. The goal of the Study Program is to employ production cost and capital expansion models to analyze planning issues and eventually summarize the results into a year-end Integrated Transmission and Resource Assessment Report. The draft Study Program for 2016 details the analytical activities that TEPPC will perform to evaluate changes and vulnerabilities to the Western Interconnection under various conditions for future 10-year and 20-year time horizons. The 20-year horizon studies include the assessment of scenarios constructed by the Scenario Planning Steering Group (SPSG).

Two time horizons will be studied as part of the 2016 Study Program.

· Ten-year Horizon (2026) – The 10-year time horizon will be used to evaluate the impact of options to meet existing and potential future energy policies, and the impact of external drivers such as technology changes may have on transmission needs and costs in the Western Interconnection. All Year 10 studies start with the 2026 Common Case, ensuring a common point of reference exists for all year 10 studies performed. The 2026 Common Case is based on stakeholder-provided assumptions regarding loads, generation and transmission. The Year 10 studies are conducted with a production cost model.

· 20-year Horizon (2036) – A set of studies representing potential energy futures for a 20-year study horizon will be evaluated using the WECC Long-Term Planning Tool (LTPT), a capital expansion model (CXM). A desired outcome, in part, of the long-term studies is to identify decisions that need to be made now in order to realize the potential energy futures being evaluated.

The Study Program is developed to:

1) Respond to requests received during the Open Season under the provisions of the TEPPC Interim Planning Protocol.

2) Incorporate relevant study needs of regional planning groups, state authorities, transmission providers and generators.

3) Develop needed models for production cost and transmission utilization studies.

4) Support the objectives of the WECC Strategic Plan by providing useful transmission insights into the implications of major policy and technology changes for the future of the western power system.

The list of proposed studies outlined in this document was prepared by the Technical Advisory Subcommittee (TAS) from an initial clustering and consolidation of study requests prepared by the Studies Work Group (SWG) for this planning year. The list includes study requests submitted under the provisions of the TEPPC Interim Planning Protocol during the request window period that ended January 31, 2016. The result of this process is the Draft 2016 TEPPC Study Program described herein. Prior to finalizing the Study Program, TEPPC will review stakeholder feedback and requests for reconsideration (see Appendix 1).

Transmission Planning and the Study Program

The objective of TEPPC’s transmission utilization and resource assessment studies is to provide an Interconnection-wide perspective on future transmission and resource adequacy needs of the Western Interconnection. This information is useful to transmission project developers, energy service providers, regulators, policymakers, and other parties involved in making public policy and investment decisions that impact the Western Interconnection. Since TEPPC’s work is one component of the many activities involved in planning, building, and operating the transmission system, this section first covers WECC’s planning activities. Following this, there is a brief description of the adaptive planning cycle of the TEPPC Interim Planning Protocol. Finally, the specific study methodology that will be used for this year’s TEPPC Study Program is described.

TEPPC’s work complements and coordinates with other transmission planning related activities. These include state and provincial integrated resource plans (IRP), regional planning group plans, state and provincial renewable portfolio standards (RPS), analyses of renewables integration by the National Renewable Energy Laboratory (NREL), the Western Electricity Industry Leaders (WEIL) studies, and the numerous initiatives by the Western Governors’ Association (WGA).

Purpose of Transmission Planning

Electric power networks are a unique part of our national infrastructure. With current technology, long-distance high-voltage lines are above ground, so they become a visible part of the landscape through which they pass. Transmission facilities also have very long lives, so decisions made today have long-lasting effects. Therefore, the objective of long-term transmission planning is to make the best network design decisions after considering possible future needs and expansion options. Few, if any, 10-year or 20-year transmission plans will come to fruition as originally conceived. However, by planning for possible future needs, flexibility is built into the network’s design that allows options to be exercised and adaptation to occur as future conditions are revealed.

TEPPC’s activities are an integral part of the Western Interconnection’s overall approach to Interconnection-wide planning of the transmission system, which has two major considerations:

1) System reliability—characterized as “keeping the lights on” while responding predictably to both planned and unplanned outages to generation and transmission system elements.

2) System utilization—a measure of the economic performance of the transmission system. Production cost studies and associated capital cost estimates for those studies provide answers to the question, “While operating within the bounds of reliable operation, how well does the transmission system perform to deliver electricity services to consumers at a reasonable cost?”

Relevance of TEPPC Planning Process to Regional Planning Efforts

The 2016 Interim TEPPC Protocol guides the 2016 TEPPC Study Program. The processes used by TEPPC are essential for some Transmission Providers (TPs), and valuable for a larger set of TPs as part of their FERC planning obligations (FERC Order 890, 1000) under Attachment K to the transmission providers’ Open Access Transmission Tariffs (OATT). Moreover, the Common Case data set that is used for conducting TEPPC studies also provides a foundational database for TPs to modify and analyze detailed and/or localized studies.

TEPPC Study Program Development

The Study Program is an adaptive process that uses results from previous study programs to not only improve the quality of the cases, but to add new models or modify study methodology to continually improve results produced by each successive study program. This expansion of planning activity is made possible, in part, by lessons learned in previous study programs. Figure 1 is taken from the Interim TEPPC Planning Protocol and presents the process and timeline for developing a Study Program. The inputs presented in Figure 1 are used by the SWG to develop a consolidated list of studies by integrating multiple needs of various stakeholders. This consolidated list of studies is then reviewed by TAS and forwarded to TEPPC for consideration. All stakeholders, including the parties who submitted study requests, are invited to attend TEPPC meetings and provide feedback and final Study Program is selected by TEPPC after due review and reconsideration if needed.

Figure 1. Study Program Development Process

Time Period

Activities

January 1-31, 2016[footnoteRef:1] [1: The existing Planning Protocol establishes a study request window from November 1 through January 31.]

· Stakeholders submit study requests during the Request Window.

· All stakeholders—including individual stakeholders and committees, subcommittees and work groups within WECC—must submit requests by January 31, 2016.

February 1 – March 31, 2016

Study Program Development

· WECC staff reviews and summarizes study requests and recommends 2016 study priorities, possible study request consolidations and availability of resources to conduct studies.

· SWG and TAS review the study requests and WECC staff-recommended priorities and then develop a proposed work plan. Recommendations may include proposals to consolidate requests which in turn may entail modifications of study requests to accommodate consolidation.

· TEPPC and stakeholders review proposed work plan.

(7 days prior to TEPPC meeting)

Post draft Study Program for stakeholder review

April 12, 2016

Work Plan Approval[footnoteRef:2] [2: The existing Planning Protocol calls for TEPPC posting of the proposed study program by April 30.]

· TEPPC approves proposed 2016 Work Plan at its scheduled meeting.

May 12, 2016 (30 days following TEPPC approval of the proposed work plan)

Reconsideration Period

· Any party who disagrees with inclusion or exclusion of a particular study request within the 2016 Study Program may submit a request for reconsideration within 30 days of TEPPC’s decision.[footnoteRef:3] [3: The existing Planning Protocol requires that requests for reconsideration be submitted by May 15. ]

June 12, 2016 (30 days following close of Reconsideration Period)

TEPPC Decision

· TEPPC will respond to requests for reconsideration no later than 30 days after the reconsideration request submittal deadline.[footnoteRef:4] [4: The existing Planning Protocol requires that TEPPC respond to requests for consideration by June 15.]

April 1 – December 31, 2016

Analysis and Reporting

· WECC staff completes analyses included in 2016 Work Plan.

· TEPPC Stakeholders review analytical results

· Reports on specific modeling analyses, as well as issue-based reports on other topics, are released as they are available.

October 1 – December 31, 2016

Transmission Planning Assessment Summary Report

· WECC staff prepares draft summary report of analytical activities completed during 2016.

· TEPPC and stakeholders review summary report.

December 13, 2016

Transmission Planning Assessment Summary Report Approval

· TEPPC approves Transmission Planning Assessment Summary Report and submits for Board approval

Lessons Learned from Previous Study Cycles

Results from previous Study Programs will be used to create the current Study Program which will inform the WECC Plan. As such, results produced from previous study programs will provide an analytical foundation from which new studies can be performed and analyzed for use in the creation of a new WECC Plan. The list of proposed studies outlined in this document has been developed and prioritized to reflect this goal.

In addition, the goal of each study program is to improve on previous study programs. As such, the studies outlined in this document consider new issues/topics of Interconnection-wide significance, and address gaps left by past study programs and plans.

Other Study Activities

In addition to the studies described in this report, TEPPC has ongoing activities that support its Study Program effort.

· WECC staff leads an effort to conduct historical analysis of system utilization.[footnoteRef:5] [5: Historical analysis of actual flows has been conducted by WECC for the past 12 years.]

· The SWG and Data Work Group (DWG) build the study databases needed for simulation studies.

· The Modeling Work Group (MWG) develops improved simulation models based on needs identified in past studies.

Each of these activities is an important element of TEPPC’s adaptive approach to developing transmission planning studies.

Types of Study Cases

Prior to the formation of TEPPC, a number of Western Interconnection transmission studies were completed using production cost simulations. These studies stimulated an interest in economic evaluation of transmission expansion and led to the formation of TEPPC. These studies were also influential in triggering interest in a number of major transmission projects now being developed across the Western Interconnection. A consistent concern from prior planning cycles was the inclusion of potentially redundant generation and transmission expansion proposals, creating a surplus of generation and transmission. The presence of surplus generation and transmission tended to mask possible congestion – eliminating it before it could be identified. To avoid this problem, the SWG uses a study methodology consisting of two types of study cases: “portfolio cases” that examine potential changes to loads or resources, relative to the Common Case; and “expansion cases” that examine potential changes to the transmission topology in addition to potential load or resource changes. The relationship between the two types of study cases is shown in Figure 2 for a set of illustrative, hypothetical cases.

Figure 2. Simulation Study Case Relationships

Common Case and Reference Case

The Common Case and Reference Case are the Study Cases from which all other Study Cases are built. The Common Case is the Year 10 “expected future” based on a compilation of all the existing and Year 10 projected load, resources, and transmission. The Reference Case is the Year 20 “possible energy future” extending the trajectory of the Year 10 Common Case assumptions another ten years into the future.

Year 20 Studies – Scenario Based Planning

Scenario-based planning is a technique for managing uncertainty in decision making. It is especially useful when long-term investments must be evaluated despite the inability to accurately predict the future. Scenarios offer a tool for describing plausible and well-researched futures and thereby enabling planning across a wider range of potential futures. This approach can spur a better understanding of emerging risks and opportunities.

Scenarios cannot take into account all aspects of the complexity of interrelationships and interdependencies of the real world. However, scenarios are a powerful tool for sensitizing decision makers to emergent key factors which can influence the outcome of their decisions. When used as a tool for guiding long-term capital decisions, scenarios can help infrastructure developers and managers to more effectively assess both the timing and scale of investments. They can also provide the time needed to create alternative financing and risk management options. In this way, these scenarios have been prepared and used by WECC and its stakeholders in the transmission planning process. Figure 3 provides a visual summary of four of the five scenarios being considered in the 20-year reliability assessment studies. A fifth scenario, the Energy-Water-Climate Change Scenario, examines the nexus between energy, water and climate change and their impact on the transmission system.

Figure 3. Scenarios used in 20 year Studies

Portfolio Cases

Portfolio Cases (PC) are developed to represent a possible pattern of future load and resource development. The type and location of incremental resources will be different among portfolio cases, based on the analysis of the WECC Loads & Resources information and study criteria defined by study requestors. Load and general policy changes can also be included to reflect varying futures. For the network topology, portfolio cases represent the 10-Year transmission system as the existing transmission plus new transmission for which construction is sufficiently certain in the given horizon year. From the Common Case, additional Portfolio Cases are developed that represent other possible patterns of load and resource developments.

Each portfolio case provides a hypothetical portfolio of resources that balance load and generation. In past TEPPC studies, the incremental resources were added in three groups:

1) renewable resources needed to meet the renewable portfolio standard (RPS) of a given state in the study year;

2) more likely planned resources listed in LRS reports; and

3) enough conventional generation to achieve load-resource balance.

Evaluation of a portfolio case is used to identify binding constraints that may suggest what additional transmission is needed to alleviate congestion. In other words, these are used to evaluate the impact of different future market, regulatory, and policy conditions on the need for transmission network expansion.

Sensitivity Cases

Sensitivity Cases are typically a set of studies consists of “single-parameter” changes within the load, resource, or transmission assumptions of a Study Case. By changing a single variable or specific set of variables such as hydro conditions or load, this set of studies informs stakeholders about how deviations in the study case assumptions can impact on the initial study case’s results.

Expansion Cases

Expansion Cases (EC) are developed from portfolio cases by adding incremental transmission and/or storage projects, or any other incremental infrastructure that may provide operational or economic benefit. This is the second step in the transmission study analysis to investigate the effects that various transmission expansion options may have on system utilization. By reporting the impact on system utilization and a capital cost estimate of different alternatives, stakeholders will be better able to judge their interest in various projects and provide a basis for further project studies.

Power Flow Export Cases

Power Flow (PF) Export Cases are power flow models (PFM) that represent the system condition of a specific hour within a production cost study case’s simulation.

Study Cases

“Study Case” generically describes other study cases that don’t fall into the above-mentioned categories. This type of study case defines numerous inputs and/or assumptions of a specific study case to evaluate the aggregate impacts (typically built from the Common Case).

Elements and Themes of this Study Program

The consolidated list of proposed study cases prepared by the SWG and TAS is provided in Appendix B. An explanation of each proposed study cluster and general study approach is located at the beginning of Appendix B. Once the Study Program is approved by TEPPC, the study formulation effort begins with a “scoping call” where the exact study specifications, timeline, and central study questions are developed by SWG leadership, WECC staff, and the study requestor(s). TEPPC will rely on a number of study requestors to provide data needed for its study cases based on the scoping call. Requests for this data will be communicated clearly and timely via the Study Scoping Form (Appendix D) that is filled out in the scoping call.

Study Consideration Criteria

The following criteria were used as guidance in soliciting the 10-year and 20-year studies.

1. The extent to which the request addresses reliability, economic and other planning concerns broadly across the Western Interconnection, rather than focusing on concerns that could be addressed more effectively within a single planning region.

1. Fundamental planning question(s) that would be answered by the requested study and the questions’ importance across multiple planning regions and among a range of stakeholders such as customers, regulators, generation developers and Transmission Providers.

2. Policy issues of national, Western Interconnection or state/provincial interest that are raised or addressed in the study request.

3. Whether the objectives of a particular study request could be met by other studies, by consolidating multiple study requests, or by conducting more generic studies the components of which (e.g., loads, resources, transmission) are sufficiently representative and informative to substantially meet the needs of individual study requests.

4. The extent to which the study request requires the use of interconnection-wide production cost models currently used by TEPPC and whether the request could be better addressed through other kinds of analyses that would be best or only conducted outside of TEPPC.

5. The degree to which the requested study is necessary to meet a member Transmission Provider's compliance with its OATT, Attachment K.

1. Whether the study case or a similar case has been evaluated previously, and if so, whether expectations regarding future conditions changed sufficiently to warrant re-study.

General Study Themes

This section describes the general study themes for the 2016 TEPPC Study Program (Appendix B). The study themes represent the areas of interest where TEPPC would like to focus its attention while leveraging both WECC analysis and studies being conducted by others.

Studying the Important Challenges to the Grid

Stakeholder requests influenced the Study Program to examine some important trends that could pose major challenges to the grid over the 10-year and 20-year study horizons. In particular, key topics to be addressed are:

· increasing levels of distributed generation;

· increasing levels of renewable generation to meet evolving policy objectives; and

· the potential increase in coal plant retirements or displacements (e.g., not explicitly retired as part of a study assumption, but rather displaced due to an indirect study assumption such as high carbon costs) in the Western Interconnection.

These study cases strive to raise and explore important questions about the reliability of the grid and whether the future system has sufficient flexibility to meet increased levels of variable generation. The use of transmission expansions to mitigate future stresses introduced by load growth and resource build-outs has been and should continue to be the focus of interconnection-wide planning efforts. In addition, it is important to explore and study how new resource and transmission technologies (e.g., storage facilities, enhancements to thermal ramping capabilities, synchrophasors, advantages of DC transmission lines) can be used to mitigate potential future reliability issues.

Unifying Planning Efforts and Tools

The desire to analyze the reliability and flexibility of the future grid requires adding new innovative tools of analysis to transmission expansion planning. TEPPC has augmented its traditional use of the production cost model (PCM) with a capital expansion model (CXM) by applying a Long Term Planning Tool (LTPT) developed by WECC to study potential long term energy futures (e.g., Year 20). WECC is also working to further integrate its PCM, CXM, and power flow model (PFM). The PCM is ideal for learning how the system may be utilized economically, where high transmission utilization exists and under what conditions. The PFM is ideal for examining the reliability of the system in greater detail through power flow (PF) analyses which could include contingency analysis, congestion analysis, reactive voltage support, transfer capabilities, and dynamic stability, to name a few. The CXM, using the LTPT, is ideal for gaining an understanding of potential energy futures and what system enhancements might be needed in for future generation and the transmission infrastructure.

In order to improve linkages between the Year 10, Year 20, resource adequacy, and reliability studies, mechanisms and processes must be developed to strengthen the linkages between the WECC planning models to create more cohesive and holistic sets of models. These mechanisms and processes must enable a seamless conversion and exchange of data inputs and results between the various planning models so that studies can be performed more holistically (e.g., build a PCM from the results of a CXM and build a PFM from the results of a PCM).

Aging Assets and Retirement of Major Base Load Resources

The focus of some study cases is on understanding the impacts of future generating resource retirements in the 10-year horizon. Planners, developers and other stakeholders in the Western Interconnection need to understand reliability and environmental implications associated with decisions to retire or maintain aging base load resources.

Collaboration With Other Efforts Beyond WECC

The core cases (Year 10 Common Case and Year 20 Reference Case) serve as foundations for other reliability studies in the Western Interconnection. In addition to running and analyzing the cases in the Study Programs, TEPPC is committed to maintaining close ties with other entities’ study efforts to provide support and maximize synergies.

Focus Areas for 2016 TEPPC Study Program

Specific focus areas for the 2016 TEPPC Study Program include:

Year 10 Studies

Core Sensitivity Studies

These studies will include variations from the Common Case such as varying load profiles, hydro resources, natural gas prices and carbon dioxide abatement prices.

Policy Drivers Impacting Resource Mix

Study requests received under this category include changes to the resource mix due to continued retirements of base-load coal-fired generators, higher targets for renewable portfolio standards and recently passed state legislations that include increased energy-efficiency penetration. The focus of studies in this category is to assess the impact of these drivers on degrees of transmission utilization, power flows (exports and imports) and dispatch flexibility while maintaining reliability.

High Distributed Energy Resource Future

Studies in this category include the assessment of higher levels of distributed energy resources and consequentially, their impact to the transmission-distribution interface and resulting implications for dispatch versus curtailment of power across the Western Interconnection.

Storage

Studies in this category will include the evaluation of pumped storage, compressed air and the interaction of such technologies with “high renewable resource rich areas” to assess the resulting impacts on transmission flows and optimal storage levels.

Transmission Utilization Changes

Studies in this category include the assessment of changes in transmission utilization that are a result of either higher levels of wind energy penetration in wind-resource rich areas of Western Interconnection and/or the impact of exporting surplus renewable resources across the North-South or South-North transmission paths.

Year 20 Studies

Studies in this category include the evaluation of future scenarios developed by the Scenario Planning Steering Group (SPSG) and two additional Year 20 studies: one examining high DG and the other examining coal retirement and an associated low-carbon pathway assessment.

Special Spatial Data Assessment Project:

This study would provide Bureau of Land Management (BLM) and Argonne National Laboratory (ANL) with spatial analyses to identify which pre-designated public land corridors for energy transmission will experience high transmission utilization to enable BLM to evaluate future physical expansion options.

Specifically, the project will focus on the Section 368 energy corridors (Energy Policy Act of 2005 (EPAct) and leverage transmission line utilization data from some of the 2016 TEPPC studies and overlay it on the transmission lines in this corridor to assess the level of transmission utilization. This overlay-based path utilization assessment would enable ANL to implement further analysis on existing versus future physical constraints of the Section 368 energy corridor.

Appendix A – 2016 TEPPC Study Program Cycle

Appendix B – 2016 TEPPC Study Program

The following high priority studies will be undertaken by TEPPC and WECC. Some studies are focused on only 10-year production cost model runs, while others ask for both 10- and 20-year analyses. Assumptions for studies featuring 10-year and 20-year analyses have the opportunity to be aligned in this study cycle. 10-year production cost studies are designated with “2026PC” or “2026EC” case IDs, 20-year capital expansion studies are designated with “2036PC” case IDs, and power flow (PF) export studies are designated with “PF” case IDs.

WECC has taken steps to develop a common dataset and analytical tools to link production cost modeling results into power flow analysis for the purpose of analyzing reliability issues. The ability to move from production cost modeling to power flow analysis has been referred to as performing a “roundtrip” analysis. At this time TEPPC and WECC are developing the capability to perform the roundtrip analysis from production cost modeling to power flow analysis. Roundtrip functionality is challenged by data set limitations and experience with the compatibility of both tools. WECC Staff intend to identify a study request to test the roundtrip functionality when some of these modeling limitations are overcome.

Common Case, Reference Case and Sensitivities:

Case ID

Case Summary

Requester(s)

Comments

2026 PC01

2026 Common Case

WECC

Year 10 “expected future”, updates 2024 Common Case

2036 PC01

2036 Reference Case

WECC

Built on assumptions in 2026 Common Case

2026 PC02

Year 10 Increased Load

PG&E

Pending TAS resolution of on-going discussions[footnoteRef:6] [6: TAS Work Groups currently discussing three options: (1) simple +/- west-wide percent change for “robustness test”, (2) developing more complex study case to represent likely extreme load futures (load & related impacts), and (3) sub-annual timeframe of extreme load (e.g., one or several extreme load days).]

2026 PC03

Year 10 Decreased Load

PG&E

2026 PC04

Year 10 Increased Hydro

PG&E

2026 PC05

Year 10 Decreased Hydro

PG&E

2026 PC06

Year 10 Increased Natural Gas Price

PG&E

2026 PC07

Year 10 Decreased Natural Gas Price

PG&E

2026 PC08

Year 10 Increased CO2 Price

PG&E

2026 PC09

Year 10 Decreased CO2 Price

PG&E

Coal Retirement /Low Carbon Studies

2026 PC10

Year 10 Coal Retirement / Low Carbon Future

PacifiCorp, SPSC/WIRAB, High Plains Express

Refresh 2024 coal retirement cases and explore repowering of lines.

2026 PC11

Diablo Canyon Power Plant Retirement

CAPUC & PG&E

Sensitivity study: Diablo Canyon Power Plant (DCPP) retired

Case ID

Case Summary

Requester(s)

Comments

Policy Drivers on Resource Mix & High DER Future

2026 PC12

Year 10 study: High Renewables with 50% CA RPS and CPP via targeted CO2 prices

CREPC/SPSC/WIRAB; PG&E; SCE

Propose to combine the following 50% RPS-CA related studies:

1. High Renewables Case with 10% step-up in other states. Identify steps to reduce congestion (CREPC/SPSC/WIRAB)

2. Model 2030 Planning assumptions with 50% CA RPS and CPP reductions in CO2 (PG&E)

3. Examine CA power exports, potential limits and reliability issues (PG&E and SCE).

2026 PC 13

Year 10 study: Double EE per SB 350

PG&E

Assess impacts to dispatch and power flows.

2026 PC 14

Year 10 study: Probabilistic assessment of any of the above studies: 2026 PC10/PC12/PC13

WECC Staff Proposal

Explore in a probabilistic (non-deterministic) setting, the impacts of high levels of Renewables on Loss of Load Probability (LOLP) and power flows.

2026 PC 15

Year 10 study: Investigate modeling improvements to represent the transmission-distribution interface, dump energy and potential for dispatch and curtailment with storage as a mitigation strategy.

CREPC/SPSC/WIRAB; PG&E and Strategen

Propose to combine the following DER study requests:

1. High DG follow-up to 2024 PC 19 to understand dump energy and potential storage options

2. Assess Transmission-Distribution interface with High DER/Storage (PG&E)

3. Compare WECC’s GridView modeling with UC Berkeley Switch Model using High Renewables, DER and Storage scenarios (Strategen).

Case ID

Case Summary

Requester(s)

Comments

Storage Studies

2026 PC 16

10 year study: Assess impact of Pump Storage in OR/WA near the top of AC-DC interties with High Renewables penetration

Clean Power Development

Requesters of Storage Studies will work to integrate where feasible, the following studies: 2026 PC 16-PC20.

2026 PC 17

10 year study: Add Compressed Air Energy Storage (1200 MW) at IPP STS’s Delta (UT) site with High Renewables resource portfolio and Zephyr Wind Project (WY).

DATC and Burbank

Requesters of Storage Studies will work to integrate where feasible, the following studies: 2026 PC 16-PC20

2026 PC 18

10 year study: Double CAES storage capacity (PC 17)

Burbank and DATC

Requesters of Storage Studies will work to integrate where feasible, the following studies: 2026 PC 16-PC20.

2026 PC19

10 year study: Double battery storage capacity in CA (1300 to 2600 MW) assuming High Renewables Portfolio.

PG&E

Requesters of Storage Studies will work to integrate where feasible, the following studies: 2026 PC 16-PC20.

2026 PC20

10 year study: High Storage case assessment that integrates the studies PC 18 and PC 19

Burbank, DATC and PG&E

Requesters of Storage Studies will work to integrate where feasible, the following studies: 2026 PC 16-PC20.

Case ID

Case Summary

Requester(s)

Comments

Transmission Changes

2026 PC 21

Year 10 assessment of how existing transmission (less specified CCTA projects) can accommodate wind additions in New Mexico (2500 MW) and Wyoming (2250 MW).

SDG&E

Possibility for integrating with 2026 PC 22.

2026 PC 22

Year 10 assessment that builds on 2026 PC 21 but with focus on examining North-South flows with increased RE in Southern CA and Southwest(AZ, NV, NM).

Pacific Gas & Electric

2026 PC 23

Year 10 assessment of North-South transmission flows with increased RE in Northern CA and Northwest (OR, WA, MT) followed by high-expansion case with high hydro conditions.

Pacific Gas & Electric

2026 PC 24

Year 10 assessment of 2026 PC 12 with the decommissioning of Eldorado-Moenkopi 500 kv with additional model-run of keeping the line in use.

Hualapai Tribe

Integrates with 2026 PC 12 and CA 50% RPS and CPP adoption.

Case ID

Case Summary

Requester(s)

Comments

Year 20 Study Cases

2034 PC 1

Assessment of SPSG Scenario 2 – Aggressive policies to reduce GHG and promote technological innovation.

SPSG

Legacy Study using the 2034 Reference Case. .

2034 PC 2

Year 20 assessment of SPSG Scenario 3 – Slow growth with focus on consumer costs

SPSG

Legacy Study using the 2034 Reference Case.

2034 PC 3

SPSG Scenario 4 – Slow growth with focus on low-hanging fruit clean energy investments.

SPSG

Legacy Study using the 2034 Reference Case.

2034 PC 4

Year 20 High DG case

SPSG

Legacy Study using the 2034 Reference Case.

2034 PC 5

Assessment of coal retirements or low-carbon pathway with electrification of infrastructure.

SPSG

Legacy Study using the 2034 Reference Case.

2034 PC 6

Analyze reliability issues (PF analyses) of 10-year Increased Renewables for California supplied by additional renewables in WY, CO, AZ, & NM

SPSG

Legacy Study using the 2034 Reference Case.

2034 PC 6

Year 20 assessment of SPSG Energy-Water-Climate Change (EWCC) Scenario

SPSG

Study may be completed using 2034 or 2036 Reference Case, depending upon timing of study case and availability of 2036 Reference Case.

Appendix B - Glossary of TEPPC Terminology

AC: Alternating Current – A type of electrical current, the direction of which is reversed at regular intervals or cycles. In the United States, the standard is 60 cycles per second, denoted as 60 Hz (Hertz).

DOE: U.S. Department of Energy – The federal agency designed “to advance the national, economic, and energy security of the United States; to promote scientific and technological innovation in support of that mission; and to ensure the environmental cleanup of the national nuclear weapons complex.”

DSM: Demand-Side Management – The term for all activities or programs undertaken by a Load-Serving Entity or its customers to influence the amount or timing of electricity they use in response to directions from the utility.

DWG: Data Work Group – A work group created by TAS that collects and verifies data used in the TEPPC database for economic studies of transmission planning. This data is made available to Regional Planning Groups, developers, regulators, and others.

EDWG: Environmental Data Work Group – A work group created by the SPSG to develop recommendations on the type, quality, and sources of data on wild lands, wildlife, cultural resources and potential water resources that can be used in transmission planning processes.

EE: Energy Efficiency – Programs and policies designed to reduce electric energy consumption or increase the efficiency of electric loads.

FERC: Federal Energy Regulatory Commission – An independent federal agency that regulates the interstate transmission of natural gas, oil, and electricity. FERC also regulates natural gas and hydropower projects.

Generation – The process of producing electricity by transforming other forms or sources of energy into electrical energy; measured in kilowatt-hours.

IRP: Integrated Resource Plan – A plan developed by an electric power provider, sometimes as required by a public regulatory commission or agency, that defines the short- and long-term capacity additions (supply-side) and demand-side management programs that it will undertake to meet projected energy demands.

Load Center: A geographic area with a concentrated electrical load.

LSE: Load-Serving Entity – An entity that secures energy and transmission service (and related Interconnected Operations Services) to serve the electrical demand and energy requirements of its end-use customers.

MW: Megawatt – 1,000 kilowatts, or 1.0 million watts; a standard measure of electric power plant generating capacity.

MWG: Modeling Work Group – A work group created by TAS that evaluates and proposes improved models for production cost simulation.

NERC: North American Electric Reliability Corporation – NERC is the electric reliability organization certified by the Federal Energy Regulatory Commission to establish and enforce reliability standards for the Bulk-Power System.

Path, or Transmission Path: A single or set of transmission lines with an established rating. There are 66 WECC-rated paths in the Western Interconnection. Paths are analogous to the term “flowgate” used in other parts of North America.

PCM: Production Cost Model – An analytic representation of an electrical generation and transmission system used to determine the most efficient dispatch of generation to meet system loads within the reliability constraints on power system operations.

Renewable Generation – Energy derived from resources that are regenerative or for all practical purposes cannot be depleted.

ROW: Right of Way – A corridor of land on which electric lines may be located. The Transmission Owner may own the land in fee, own an easement, or have certain franchise, prescription, or license rights to construct and maintain lines.

RPS: Renewable Portfolio Standard – A regulation that requires an established level of production or purchase of energy from renewable energy sources such as wind, solar, biomass, and geothermal.

Scenario – A plausible future that is defined by various economic, social, political, and technological factors.

RPCG: Regional Planning Coordination Group – An entity comprised of representatives of each Western Planning Region and of Canadian planning regions that coordinates regional planning activities of mutual interest related to TEPPC activities.

RPCG Common Case Transmission Assumptions (CCTA) – A list of transmission projects having a high-probability of being constructed within the 10-year study horizon year. The RPCG facilitated the preparation of and developed the criteria for the RPCG Common Case Transmission Assumptions. These projects provide an assumed minimum transmission system starting point for TEPPC’s future planning studies, and are included in the Year 10 Common Case and Year 10 and Year 20 study cases.

RPG: Regional Planning Group – An organization that coordinates planned transmission system changes within a defined geographical area in the Western Interconnection. WECC currently recognizes seven RPGs in the Western Interconnection:

1) Alberta Electric System Operator (AESO);

2) British Columbia Coordinated Planning Group (BCCPG);

3) California Independent System Operator (CAISO);

4) ColumbiaGrid;

5) California Transmission Planning Group (CTPG);

6) Northern Tier Transmission Group (NTTG); and

7) WestConnect.

SPSC: State-Provincial Steering Committee – A committee established in 2009 to provide input into regional transmission planning; to improve the efficient use of the existing grid; and to enable the integration of variable energy resources in the Western Interconnection. The SPSC is composed of appointees from each state and province in the Western Interconnection, and comprises one-third of the SPSG membership. The Western States’ Water Council and the Western Governors’ Wildlife Council are ex-officio members of the SPSC.

SPSG: Scenario Planning Steering Group – The SPSG is a multi-constituency steering group that provides strategic guidance and direct participation in TEPPC activities. The purpose of the SPSG is to provide: 1) strategic guidance to TEPPC; 2) scenarios to be modeled in transmission planning studies; 3) modeling tools to be used; and 4) key assumptions to be used in creating and reviewing the scenarios.

Stakeholder – A person or entity interested in or wishing to participate in WECC’s planning activities.

Study Case – A set of load, resource, and network topology conditions used to model the performance of the Western Interconnection transmission grid.

Study Program – A set of studies, developed under the provision of the TEPPC Interim Planning Protocol, to be completed by TEPPC within that study year. Each Study Program is developed based on consideration and prioritization of all study requests received for that year.

SWG: Studies Work Group – A work group created by TAS that directs studies for which TEPPC is the study lead, establishes assumptions, and confirms methodology.

TAS: Technical Advisory Subcommittee – A subcommittee created by TEPPC that collects and disseminates data for historic and forward-looking planning studies. TAS subgroups include the Data Work Group, Modeling Work Group, and Studies Work Group.

TEPPC: Transmission Expansion Planning Policy Committee – A WECC Board committee that conducts and facilitates economic transmission planning for the Western Interconnection. TEPPC activities include fulfilling transmission owner/operator and Regional Planning Group planning requirements under FERC Order 890. TEPPC has a balanced membership comprised of individuals from WECC-member organizations and stakeholders.

Transmission – An interconnected group of lines and associated equipment for the movement or transfer of electric energy between points of supply and points at which it is transformed for delivery to customers or is delivered to other electric systems.

WECC: Western Electricity Coordinating Council – The Regional Entity responsible for coordinating and promoting Bulk Electric System reliability in the Western Interconnection.

WGA: Western Governors’ Association – An independent, nonpartisan organization of Governors representing 19 Western states, and three U.S.-flag Pacific islands. The WGA identifies and addresses key policy and governance issues in natural resources, the environment, human services, economic development, international relations, and public management.

Western Interconnection – The interconnected electrical system that encompasses the provinces of Alberta and British Columbia, the northern portion of Baja California (Mexico), and all or portions of the 14 Western states in between.

Appendix C - TEPPC 2015 Study Program Study Case Scoping Form

The purpose of this document is to define the overall scope of a TEPPC study case so that the study requestor, TEPPC, and the WECC staff have a common understanding of the expectations and limitations of the study that will be completed.

Study Case Name

Date of Adoption

Case Number

Study Timeframe

Study Requestor(s)

Priority

Study Case Summary(ies)

Key Questions to be Answered/Addressed by the Study

This information will be used to identify data inputs required for the study as well as key outputs that should be communicated back to the study requestor.

1.

2.

Study Case Tasks

Requestor Task(s)

Responsible Party(ies)

Completion Date

1.

2.

WECC Staff or Work Group Task(s)

Responsible Party(ies)

Completion Date

1.

2.

Key Limitations

What issues will not be addressed by this TEPPC study due to limitations in time, resources, or modeling tools?

1.

2.

Other Study Information

Link to background material (reports/analysis completed in support of study) and/or study results