N-18Response to Undertakings - Redacted
54 passages
NERC conducted the Interregional Transfer Capability Study (ITCS) to inform the potential need for more electric transmission transfer capability to enhance reliability in the United States[.](#page-53-1) 1 The ITCS was completed and filed...
AI summary NERC conducted the Interregional Transfer Capability Study (ITCS) to assess the need for enhanced electric transmission transfer capability in the U.S. and Canada, with findings that highlight both similarities and differences between the two systems. The study was mandated by Congress and filed with FERC.
Executive Summary The North American grid is a complex machine that has evolved over many decades; it integrates a network of generation, transmission, and distribution systems across vast geographic areas. As a result of the changing reso...
AI summary The North American grid is a complex system that requires a strong, flexible, and resilient transmission network to meet customer demand, especially with changing resource mixes and extreme weather. Canadian systems are vital to the North American bulk power system, and NERC's analysis supports the reinforcement and expansion of inter-regional transmission to ensure reliability, aligning with Canada's Clean Electricity Strategy.
A Critical Study: Scope and Focus NERC assessment[s](#page-54-6) 8 identified the need for more transmission throughout North America and a strategically planned resource mix[9](#page-54-7) to address these changes and support the ongoing...
AI summary The text discusses the need for enhanced transmission infrastructure and a strategically planned resource mix to support electrification and address challenges from extreme weather. It emphasizes the importance of energy reliability and adequacy, referencing NERC assessments and the Canadian Analysis.
Executive Summary informed planning at a broad interregional level to support future grid reliability and resilience. A common approach, consistent assumptions, and coordinated results were key elements of the Canadian Analysis. The Canadi...
AI summary The Canadian Analysis evaluates transmission transfer capability and energy margin across Canadian regions, emphasizing the need for interregional coordination to improve grid reliability. It does not provide economic or policy assessments, nor does it endorse specific projects or replace existing transmission planning efforts. The study highlights opportunities for optimizing reserve use and the importance of integrated planning.
Key Findings–Energy Margin Analysis (2033) - Canadian systems were found to be increasingly vulnerable during extreme weather due to anticipated load increases and the changing resource mix. Transmission limitations, and potential for ener...
AI summary Canadian energy systems face increased vulnerability during extreme weather due to load increases and resource mix changes. Transmission limitations and energy shortages were identified across multiple regions, with Nova Scotia and Québec facing significant deficits. Enhancing transfer capability, especially between Nova Scotia and New Brunswick, could address these issues.
Various Options to Address Resource Deficiency Risks When addressing the identified risks, entities have various tools at their disposal. While the Canadian Analysis identifies additions to transfer capability as one means of addressing ex...
AI summary The document outlines various strategies to address resource deficiency risks, including internal resource development, transmission enhancements, and demand-side management. It emphasizes the need for a balanced approach, considering the impacts of each option, and highlights the importance of reliable generation, cost-allocation mechanisms, and energy storage.
Chapter 1: Overview of Scope and Terminology This study, which follows the ITCS,[24](#page-64-2) was requested by Canadian government entities and industry leaders and provides valuable insights regarding potential risks to their systems d...
AI summary This chapter outlines the Canadian Analysis, a comprehensive study requested by Canadian government entities and industry leaders to assess transfer capabilities between TPRs and identify potential energy deficits during extreme events. The study uses historical data and modeling approaches to evaluate reliability and inform future planning.
Study Scope The transfer capability analysis studied forecasted 2024 Summer and 2024/25 Winter conditions. [26](#page-64-4) This analysis produced a set of transfer capability limits between neighboring TPRs. More information is provided i...
AI summary The study analyzed transfer capability limits between TPRs under 2024 Summer and 2024/25 Winter conditions, using energy margin analysis to identify TPRs with energy deficiencies. The analysis focused on identifying potential transfer capability additions to mitigate these deficiencies, while excluding probabilistic resource adequacy analysis and local resource additions.
Transmission Topology The TPRs used for this study are shown in [Figure 1.2](#page-67-1) . Figure 1.2: Transmission Planning Regions The transfer capability analysisidentified a set of interfacesthat included all pairs of neighboring TPRs...
AI summary The document discusses the transmission topology and planning regions (TPRs) used in a study, including transfer capability analysis, interface limits, and modeling of existing and potential transmission links. It highlights the representation of TPRs, interface limits in both directions, and the inclusion of generation sources like Muskrat Falls and Churchill Falls in the model.
Important Study Considerations While the Canadian Analysis used engineering study approaches deployed within industry planning processes, it is not a planning study. Reliability, in the form of energy adequacy, is the sole focus of the stu...
AI summary The study focuses on reliability and energy adequacy, not economic justification for transmission upgrades. It identifies potential increases in transfer capability during extreme conditions but does not consider local solutions or endorse specific projects. NERC acknowledges additional benefits of transmission beyond reliability.
Base-Case Development The current transfer capability calculation was performed using relevant Eastern Interconnection and Western Interconnection base cases with consistent criteria and assumptions. System models representing the Eastern...
AI summary The Base-Case Development section outlines the process used to update transfer capability calculations for the Eastern and Western Interconnections, including updates to generation, load forecasts, resource dispatch, and transmission system topology. NERC requested these updates in November 2023.
Contingencies The transfer analysis simulated contingencies, namely the unplanned outage of system elements, to ensure that the system would remain reliable during the energy transfer. The following NERC Reliability Standard TPL-001-5.1[38...
AI summary The transfer analysis simulated unplanned outages of system elements to ensure system reliability during energy transfer. NERC Reliability Standard TPL-001-5.1 was used, focusing on P1 contingencies such as loss of generators, transmission lines, and transformers operating at 100 kV or above.
Monitored Facilities and Thresholds Facility monitoring criteria and thresholds were established to prevent undue limitation of transfer capability results based on heavily loaded, electrically distant elements. These practices followed in...
AI summary Facility monitoring criteria and thresholds are established to prevent undue limitations on transfer capability results caused by heavily loaded or electrically distant elements. These criteria follow industry-accepted methods to ensure transmission facilities minimally involved in interregional transfers do not artificially constrain transfer limits, as detailed in the scoping document.
Special Interface Considerations Several interfaces have known operating procedures or other special circumstances. In many cases, these are remedial action schemes and/or flow control devices (e.g., phase angle regulators (PAR) or dc line...
AI summary The document discusses special interface considerations in power systems, including the use of flow control devices like phase angle regulators (PAR) and dc lines, and how they affect transfer capability calculations. It outlines procedures for modeling these interfaces and coordinating with regional entities during transfer analysis.
Transfer Capability Results Results are presented from west to east as follows: [British Columbia](#page-76-0) <-> Washington [British Columbia <-> Alberta](#page-76-1) [Alberta <-> Wasatch Front](#page-77-0) [Alberta <-> Saskatchewan](#pa...
AI summary The document presents transfer capability results across various regions in Canada, including British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick, and New England, highlighting interregional transmission links.
Interface Direction 2024 Summer 2024/25 Winter British Columbia -> Washington 2,358 MW 2,170 MW Washington -> British Columbia 2,897 MW 2,795 MW British Columbia <-> Alberta
AI summary The document presents data on electricity interface directions between British Columbia and Washington for the 2024 Summer and 2024/25 Winter periods, with values in megawatts (MW). It also references a section on British Columbia and Alberta, though no data is provided for this interface.
Interface Direction 2024 Summer 2024/25 Winter British Columbia -> Alberta 846 MW 855 MW Alberta -> British Columbia MW40 1,000 MW41 1,000 40 This value is a stability limitation. 41 This value is a stability limitation. Alberta <-> Wasatc...
AI summary The document provides a table showing the interface direction and power transfer values between British Columbia and Alberta for the 2024 Summer and 2024/25 Winter periods. It also mentions stability limitations for certain values and references an interface between Alberta and Wasatch Front.
Interface Direction 2024 Summer 2024/25 Winter Alberta -> Wasatch Front 957 MW 1,280 MW Wasatch Front -> Alberta 525 MW 477 MW Alberta <-> Saskatchewan
AI summary The document presents data on the flow of electricity between Alberta and the Wasatch Front during the 2024 Summer and 2024/25 Winter periods, indicating the direction and volume of power transfer between these regions.
Special Information: dc-only interface Interface Direction 2024 Summer 2024/25 Winter Alberta -> Saskatchewan 150 MW 150 MW Saskatchewan -> Alberta 150 MW 150 MW Saskatchewan <-> SPP North
AI summary The document outlines the dc-only interface capacities between Alberta and Saskatchewan for the 2024 summer and 2024/25 winter periods, with each direction having a capacity of 150 MW. It also mentions the interface between Saskatchewan and SPP North.
Interface Direction 2024 Summer 2024/25 Winter Saskatchewan -> SPP North 165 MW 663 MW SPP North -> Saskatchewan 370 MW 286 MW Saskatchewan <-> Manitoba
AI summary The table shows the interface direction and power transfer between Saskatchewan and Manitoba for the 2024 Summer and 2024/25 Winter periods, indicating the flow of electricity between the two regions.
Interface Direction 2024 Summer 2024/25 Winter Saskatchewan -> Manitoba 106 MW 473 MW Manitoba -> Saskatchewan 306 MW 499 MW Manitoba <-> MISO West
AI summary The table shows the interface direction between Saskatchewan and Manitoba for the 2024 Summer and 2024/25 Winter periods, with power flow amounts in MW. It also references Manitoba's interaction with MISO West.
Interface Direction 2024 Summer 2024/25 Winter Manitoba -> MISO West 3,772 MW 3,633 MW MISO West -> Manitoba 0 MW 801 MW Manitoba <-> Ontario
AI summary The table shows the interface direction and capacity between Manitoba and MISO West for the 2024 summer and 2024/25 winter periods, with a specific focus on the Manitoba <-> Ontario interface. The data indicates a significant flow of power from Manitoba to MISO West during the summer, while there is a notable increase in flow from MISO West to Manitoba during the winter.
Interface Direction 2024 Summer 2024/25 Winter Manitoba -> Ontario 1,306 MW 2,203 MW Ontario -> Manitoba 1,961 MW 2,336 MW Ontario <-> MISO West
AI summary The table shows the flow of electricity between Manitoba and Ontario during the 2024 Summer and 2024/25 Winter periods, with specific values for each direction. The section also references the interface between Ontario and MISO West.
Interface Direction 2024 Summer 2024/25 Winter Ontario -> MISO West 2,424 MW 1,862 MW MISO West -> Ontario 1,776 MW 2,163 MW Ontario <-> MISO East
AI summary The text presents a table showing the flow of electricity between Ontario and MISO West during the 2024 Summer and 2024/25 Winter periods. It includes the interface direction and the corresponding megawatt values for each season.
Interface Direction 2024 Summer 2024/25 Winter Ontario -> MISO East 2,348 MW 1,649 MW MISO East -> Ontario 2,160 MW 2,081 MW Ontario <-> New York
AI summary The table shows the interface direction between Ontario and MISO East for the 2024 summer and 2024/25 winter, with corresponding megawatt values. It also references Ontario's interface with New York.
Interface Direction 2024 Summer 2024/25 Winter New Brunswick -> Nova Scotia MW47 170 MW48 100 Nova Scotia -> New Brunswick MW49 350 MW50 350 47 This value is a stability limitation, adjusted based on exports to Prince Edward Island. 48 Thi...
AI summary The document presents data on the interface direction between Nova Scotia and New Brunswick for the 2024 Summer and 2024/25 Winter periods, indicating power flow in megawatts (MW) and noting stability limitations for certain values.
Interface Direction 2024 Summer 2024/25 Winter Into Saskatchewan TTC 754 MW 743 MW dc-only interfaces 150 MW 150 MW Total of TTC and dc-only interfaces 904 MW 893 MW Percentage of Peak Load 25% 22% Into Manitoba
AI summary The document presents data on interface directions into Saskatchewan and Manitoba, including TTC and dc-only interfaces, their respective capacities, and the percentage of peak load they represent for the 2024 Summer and 2024/25 Winter periods.
Interface Direction 2024 Summer 2024/25 Winter Into Manitoba TTC MW54 1,961 2,483 MW Percentage of Peak Load 66% 55% 54 Value is from the Ontario to Manitoba interface, as the total import interface calculation was more limiting. Into Onta...
AI summary The document provides information on the interface direction and percentage of peak load for Manitoba and Ontario during the 2024 Summer and 2024/25 Winter periods. It mentions the Ontario to Manitoba interface and the total import interface calculation.
Interface Direction 2024 Summer 2024/25 Winter Into New Brunswick TTC MW60 900 MW61 900 dc-only interfaces 742 MW 773 MW Total of TTC and dc-only interfaces 1,642 MW 1,673 MW Percentage of Peak Load 82% 46% Into Nova Scotia
AI summary The document provides a table comparing interface directions into New Brunswick and Nova Scotia for the 2024 Summer and 2024/25 Winter periods, including metrics such as MW, dc-only interfaces, total interfaces, and percentage of peak load.
Storage Modeling Storage resources, both pumped storage hydro and battery storage, were modeled as two distinct units for each TPR. Information regarding installed capacity for each resource type for existing and future capacity builds was...
AI summary Storage resources, including pumped storage hydro and battery storage, were modeled separately for each TPR, with assumed durations of 12 and 4 hours respectively. Storage units dynamically charge and discharge based on energy margins, with efficiency losses of 30% and 13% respectively. The model does not optimize imports/exports between TPRs, though imports can be used for recharging during grid stress.
Step 1: Identify Hours of Resource Deficiency The transfer capability additions process begins with calculating the hourly energy margin for each TPR. Unlike traditional planning reserve margins that evaluate the supply and demand during e...
AI summary The energy margin analysis calculates the hourly energy margin for each TPR over 12 weather years, assessing potential surplus or deficit across all hours of the year. This method considers variable renewables, storage scheduling, outages, and weather-dependent load fluctuations, providing a time-synchronized dataset for comparing TPRs.
Energy Transfers [Figure 5.3](#page-98-0) illustrates the relationship between the hourly energy margin and the conditions under which a TPR may import or export energy. This is crucial for understanding how energy transfers are modeled. F...
AI summary The document discusses energy transfers between Transmission Planning Regions (TPRs), focusing on how surplus and deficit energy is managed based on hourly energy margins. It outlines the tight margin level (yellow zone) and minimum margin level (red zone) that dictate when energy is imported or exported, and how scarcity weighting factors influence the decision-making process during energy shortages.
Metrics Three important points can be considered in [Figure 5.4](#page-99-0) above: • Point 1 indicates that a TPR, in isolation, is below the tight margin level but there is sufficient transfer capability to import energy from its neighbo...
AI summary The text discusses three key points related to transmission planning regions (TPRs) and their margins. It explains interchange hours, tight margin hours, and resource deficiency hours, highlighting how transfer capability and load management affect system reliability and energy availability.
The model performed the above analysis for all TPRs across all hours over 12 weather years. The calculated metrics, which include the hourly energy margin, are shown in Table 5.1 . Table 5.1: Calculated Metrics Metric Units Description Ene...
AI summary The text describes the analysis performed by a model across all Transmission Planning Regions (TPRs) over 12 weather years, focusing on calculated metrics like energy margin, interchange hour, tight margin hour, resource deficiency hour, and congestion hours, which are detailed in Table 5.1.
٦ Table 5.2: Maximum Resource Deficiency (MW) by TPR and Weather Year (2033 Case) Transmission Planning Region WY2007 WY2008 WY2009 WY2010 WY2011 WY2012 WY2013 WY2019 WY2020 WY2021 WY2022 WY2023 Max Resource Deficiency British Columbia 0 0...
AI summary Table 5.2 presents the maximum resource deficiency (MW) by Transmission Planning Region (TPR) and weather year for the 2033 case. The largest maximum resource deficiency across all 12 weather years is identified as a critical input for Step 4.
Step 3: Prioritize Constrained Interfaces Step 3 focuses on identifying constrained interfaces. After determining which TPRs are in deficit (Step 1) and to what extent (Step 2), the third step is to determine which specific interfaces are...
AI summary Step 3 of the process involves identifying constrained interfaces by analyzing transmission capacity limits during tight margin hours. It calculates the number of hours each interface is congested and evaluates the scarcity weighting factors of TPRs to determine candidates for increasing transfer capability.
Interface Weight (%) Addition (MW) Ontario to Québec 25% 852 New York to Québec 41% 1,431 New England to Québec 29% 986 New Brunswick to Québec 5% 186 Total 100% 3,454 Figure 5.6: Québec Iteration 2 Allocation of Additional Transfer Capabi...
AI summary Figure 5.6 shows the allocation of additional transfer capability from various regions to Québec in 2033. After three iterations of increasing transfer capability, the maximum resource deficiency is fully mitigated, with the third iteration allocating 50% to New York, 28% to Ontario, 21% to New England, and 1% to New Brunswick.
Other Considerations In addition to the criteria above, the following factors should be noted: - Additions were only considered between neighboring TPRs. Transfer capability additions that solely benefit a "neighbor's neighbor" are outside...
AI summary The text outlines additional considerations in transmission planning, focusing on the scope of transfer capability additions, prioritization based on resource surplus, the bi-directional nature of some additions, and the ability of generating units to connect to multiple interconnections without depleting transfer capability.
Example of Transfer Capability Additions Continuing with the Québec example, [Table 5.3](#page-104-0) below shows the cumulative iterations of increases to transfer capability. In accordance with the criteria above, these values were round...
AI summary The text provides an example of transfer capability additions using the Québec case, referencing Table 5.3 which shows cumulative increases rounded to the nearest 100 MW.
2024 Energy Margin Analysis Results The results of the energy margin analysis for the 2024 case are summarized in Table 6.1 , which provides an overview of the maximum resource deficiencies observed across various TPRs and weather years. T...
AI summary The 2024 Energy Margin Analysis Results summarize the maximum resource deficiencies observed across various TPRs and weather years, highlighting winter and summer shortfalls. The analysis considers resource sharing between TPRs based on availability and transfer capabilities.
1 Table 6.4: Maximum Resource Deficiency (MW) by TPR and Weather Year (2033 Case) Transmission Planning Region WY2007 WY2008 WY2009 WY2010 WY2011 WY2012 WY2013 WY2019 WY2020 WY2021 WY2022 WY2023 Max Resource Deficiency British Columbia 0 0...
AI summary Table 6.4 shows maximum resource deficiency (MW) by TPR and weather year for the 2033 case. The 2033 results indicate a more widespread challenge to energy adequacy compared to the 2024 case, driven by load growth, changing resource mix, and current transfer capability application.
As a result of the above analysis, transfer capability additions that could mitigate potential energy deficiencies were identified for five TPRs, summarized in Table 6.7 , after following the six-step process described in Chapter 5 . The t...
AI summary The analysis identified transfer capability additions in five TPRs to mitigate energy deficiencies, ordered by the number of resource deficiency hours. Additional TPR-specific details are in Chapter 8, and alternative transfer capability additions may also be effective.
Relationship Between Generation and Transmission The study found a nuanced but crucial relationship between generation and transmission. If multiple neighboring TPRs lack resources, additional transfer capability offers limited help becaus...
AI summary The study highlights the complex relationship between generation and transmission, emphasizing that additional transfer capability has limited benefits when neighboring TPRs lack resources or have surplus energy. It underscores the need for balanced planning as resource mixes and load growth evolve, noting that interregional transfer capability was evaluated for reliability but tradeoffs were not assessed.
Pronounced Mutual Benefits of Transfer Capability Across Interconnections The study highlighted the mutual and significant benefits of bi-directional transfer capability across Interconnections, where geographic diversity in resource avail...
AI summary The study emphasizes the mutual benefits of bi-directional transfer capability across interconnections, particularly during extreme weather events. Examples include support between Québec and the Eastern Interconnection, and between the Western and Eastern Interconnections, highlighting the importance of collaborative planning among neighboring regions.
Table 7.1: Comparison of Maximum Resource Deficiency (in MW) Transmission Planning Region Max Resource Deficiency (3% Margin) Max Resource Deficiency (6% Margin) Change in Max Resource Deficiency British Columbia 0 0 0 Alberta 764 1,463 69...
AI summary The table compares maximum resource deficiencies across various transmission planning regions under different margin levels. The analysis emphasizes the need for holistic generation and transmission planning, as stricter margin levels increase resource deficiencies. In extreme cold conditions in WY2023, deficiencies in Québec, New Brunswick, and Nova Scotia could not be resolved due to lower transfer capability additions into Québec.
Updated Loads and Resources from the 2024 LTRA Sensitivity In this sensitivity, load and resource forecasts were updated based on 2024 LTRA data. Due to its mandated timing, this was not an option available for the original ITCS. This sens...
AI summary This sensitivity analysis updates load and resource forecasts based on 2024 LTRA data, resulting in reduced maximum resource deficiencies in some provinces and increased deficiencies in others, notably Alberta. The findings inform the Canadian Analysis but may differ if actual conditions vary from projections.
Table 7.2: Comparison of Maximum Resource Deficiency in 2033 (in MW) Transmission Planning Region Max Resource Deficiency (2023 LTRA Data) Max Resource Deficiency (2024 LTRA Data) Change in Max Resource Deficiency British Columbia 0 0 0 Al...
AI summary Table 7.2 compares the maximum resource deficiency in 2033 (in MW) across different transmission planning regions using 2023 and 2024 LTRA data. The data shows significant changes in resource deficiencies, particularly in Ontario and Québec, where deficiencies decreased substantially.
Chapter 8: TPR-Specific Results The following pages provide detailed results for each TPR, including information on each interface transfer capability, additions to transfer capability, information on each model iteration, assumed resource...
AI summary Chapter 8 presents TPR-specific results, including transfer capability details, model iterations, resource mix, peak load data, and resource deficiency events. Summary maps highlight current and added transfer capability for 2033, organized by TPR.
British Columbia Total Transfer Capability (TTC) Summary Interface Name Current Summer (MW) Current Winter (MW) Additions (MW) Resulting Summer (MW) Resulting Winter (MW) Washington to British Columbia 2,897 2,795 N/A N/A N/A Alberta to Br...
AI summary The document provides a summary of total transfer capability (TTC) and energy adequacy data for British Columbia, including interface limits, resource types, and peak demand figures for 2024 and 2033. It outlines the capacity and load data, including thermal, hydro, and variable renewable resources, and evaluates energy deficiency events across multiple iterations.
Capacity and Load Data (in MW) Resource Type 2024 2033 Thermal 14,538 14,916 Hydro 894 894 Variable Renewable 7,642 11,334 Energy Limited 190 463 Total 23,264 27,607 Note: Thermal and hydro values represent winter ratings Summer Peak 11,44...
AI summary The document presents capacity and load data for thermal, hydro, and variable renewable resources in 2024 and 2033, along with resource deficiency events and transfer capability summaries for Saskatchewan. It includes details on energy adequacy across multiple iterations and the percentage of seasonal peak covered by transfer capabilities.
Capacity and Load Data (in MW) Resource Type 2024 2033 Thermal 3,725 4,248 Hydro 867 867 Variable Renewable 697 942 Energy Limited 67 127 Total 5,356 6,184 Summer Peak 3,517 3,951 Winter Peak 3,873 4,326 Resource Deficiency Events Event Da...
AI summary The document presents capacity and load data for 2024 and 2033, including resource types such as thermal, hydro, and variable renewable energy. It also includes historical data on resource deficiency events and total transfer capability between Ontario and Manitoba.
Capacity and Load Data (in MW) Resource Type 2024 2033 Thermal 21,010 20,609 Hydro 8,747 8,747 Variable Renewable 7,593 7,593 Energy Limited 810 1,825 Total 38,160 38,774 Note: Thermal and hydro values represent winter ratings Summer Peak...
AI summary The document presents capacity and load data for 2024 and 2033, including thermal, hydro, and variable renewable resources. It also includes details on resource deficiency events and transfer capability summaries for Quebec, highlighting the expansion of TTC and its percentage of seasonal peak demand.
Capacity and Load Data (in MW) Top 20 events listed. Additional 24 events… 136 209.9 3,525 Total Transfer Capability (TTC) Summary Interface Name Current Summer (MW) Current Winter (MW) Additions (MW) Resulting Summer (MW) Resulting Winter...
AI summary The document presents capacity and load data, including transfer capability summaries and energy adequacy by iteration. It outlines interface limits, seasonal peak percentages, and resource deficiencies across different iterations, highlighting changes in thermal, hydro, and variable renewable resources from 2024 to 2033.
Ī Table C.1: 2024 Cap acity by Resource Type and TPR (in M IW) Transmission Planning Region Coal Natural Gas Oil Nuclear Other Hydro Wind Utility- Scale Solar Distrib. Solar Pumped Storage Battery Storage Demand Response British Columbia 0...
AI summary Table C.1 presents the 2024 capacity by resource type across various transmission planning regions in Canada, including data on coal, natural gas, oil, nuclear, hydro, wind, solar, and demand response. Table C.2 outlines tier 1 additions and retirements by resource type and transmission planning region.