Topic:"Transmission Planning" in M12916

TABLE OF ABBREVIATIONS Abbreviation Description 10 YSO 10-Year System Outlook AAS Automatic Action Schemes BESS Battery Energy Storage System CER Clean Electricity Regulations CO2 Carbon Dioxide CPP Critical Peak Pricing DC Direct Current...

AI summary The document contains a table of abbreviations used in a Nova Scotia regulatory proceeding, including terms related to energy, environmental regulations, and infrastructure.

1 INTRODUCTION IESO Nova Scotia was established under the More Access to Energy Act as the province's independent system operator, responsible for resource planning, including resource adequacy assessments, transmission planning, and procu...

AI summary IESO Nova Scotia, established under the More Access to Energy Act, is responsible for resource planning and transmission planning. This document outlines the inaugural 10-Year System Outlook, with filing requirements for the Load Forecast and 10YSO reports, previously managed by NS Power and now under IESO Nova Scotia.

System Peak (MW) Net System Requirement (GWh) Year System Peak (MW) Growth (%) Nova Scotia Power Net System Requirement (GWh) Renewable -to Retail Energy (GWh) Municipa lity Energy (GWh) Behind-the Meter Solar (GWh) IESO-NS Net System Requ...

AI summary The table provides a projection of system peak demand and net system requirements for Nova Scotia from 2026 to 2036. It includes data on renewable energy, municipal energy, behind-the-meter solar, and the IESO-NS net system requirement. Footnotes reference a Wholesale Market Backup/Top-up Service Tariff, a letter from IESO NS to the NSEB, and a 2026 Load Forecast Report.

5.1 Transmission System Design Consistent with good practice, IESO Nova Scotia utilizes a set of deterministic criteria for its interconnected transmission system that combines protection performance specifications with system dynamics and...

AI summary IESO Nova Scotia employs deterministic criteria for its interconnected transmission system, ensuring adequacy and security after faults or disconnections. The system is classified under Nova Scotia System Design Criteria, which govern protection performance and system dynamics.

5.1.1 Interconnection Requirements IESO Nova Scotia sets performance and interconnection requirements for BESS, generation, and load connecting to the Nova Scotia transmission system. These performance and interconnection requirements will...

AI summary IESO Nova Scotia establishes interconnection requirements for BESS, generation, and load connecting to the transmission system. These requirements are being refined as technology advances and local experience grows. Inverter-based resources (IBRs) like solar and wind can be integrated, though they may require additional grid support mechanisms. The TSIR, last updated in February 2025, will be reviewed in 2026.

5.2.1 Generator and BESS Interconnection The Combined Transmission & Distribution (T&D) Advanced Stage Interconnection Request Queue[38](#page-23-1) provides the location and size of generating and BESS facilities seeking interconnection w...

AI summary The document outlines the status of generator and BESS interconnection requests in Nova Scotia, noting that 20 interconnection requests are associated with 18 projects expected to connect to the transmission system before 2030. These projects involve Transmission Provider's Interconnection Facilities (TPIF) and Network Upgrades (NU), though work related to these is not included in the report.

5.2.3 OATT Transmission Service Queue As of June 4, 2026 there are three requests in the Open Access Transmission Tariff (OATT) Transmission Queue. [39](#page-24-0) Information under project location reflects the non-confidential informati...

AI summary As of June 4, 2026, there are three requests in the OATT Transmission Service Queue. The locations of generating facilities and loads are considered confidential under Section 17.2 of the OATT and are not publicly available on OASIS.

5.3.1 Western Valley Transmission System The Western Valley transmission study was initiated to identify if load growth and new generation in the area necessitate system upgrades and/or protection scheme changes. System upgrades could incl...

AI summary The Western Valley transmission study was initiated to assess if load growth and new generation in the area require system upgrades or changes to protection schemes. Upgrades may include reactive power sources, while protection changes may involve Automatic Action Schemes (AAS) or Remedial Action Schemes (RAS). The study covers 2027 and 2032 for both normal and N-1 scenarios, with 2027 results identifying necessary upgrades.

5.4 Planned Projects The transmission plan presented in this section provides a summary of the planned reinforcement of the Nova Scotia transmission system. The proposed projects are required to maintain system reliability and security and...

AI summary This section outlines planned transmission system reinforcements in Nova Scotia to ensure reliability, security, and compliance with standards. Projects are based on system impact studies and may change due to technical studies, load forecasts, or other factors determined by IESO Nova Scotia.

5.4.1 Reliability Intertie On April 10, 2025, Wasoqonatl Transmission Incorporated (WTI) filed the NS-NB Reliability Intertie Project Application to build the reliability intertie, a second 345 kV AC transmission line between the Nova Scot...

AI summary On April 10, 2025, Wasoqonatl Transmission Incorporated (WTI) submitted an application for the NS-NB Reliability Intertie Project, which was approved by the NSEB on November 20, 2025. This project involves constructing a second 345 kV AC transmission line between Nova Scotia and New Brunswick to support renewable energy integration and meet provincial renewable energy mandates.

5.4.2 Synchronous Condensers In order to accommodate the generation identified in Sectio[n 5.2.1](#page-23-2) , new synchronous condenser installations are required to be added to the transmission system by 2030. At present, five condenser...

AI summary To accommodate identified generation, new synchronous condenser installations are required by 2030, with five units planned at specific locations. Each unit will need dedicated circuit breakers and substation terminals, and additional condensers may be needed for future wind projects.

5.4.3 Transmission Development Project List [Table 9](#page-26-0) below lists the transmission system development projects identified by IESO Nova Scotia which must be completed over the 10-Year System Outlook horizon.

AI summary The document outlines the transmission development projects identified by IESO Nova Scotia that must be completed over the 10-Year System Outlook horizon, as listed in Table 9.

Table 9: Transmission Project List 2026-2036 Project Type Location Year Status Project Description 2026 Line Upgrade L6531 2026 Planned L6531 Thermal Upgrade to 60 deg C 2027 Line Rebuild L6004 2027 Planned L6004 Thermal Upgrade (75 deg C...

AI summary Table 9 outlines a list of planned transmission projects in Nova Scotia from 2026 to 2036, including line upgrades, rebuilds, new capacitor banks, transformer replacements, and new lines. These projects aim to enhance grid reliability and capacity in response to load studies and future energy demands.

6 CONCLUSION This report constitutes IESO Nova Scotia's 10-Year System Outlook for the 2026-2036 horizon and satisfies the requirement under Section 3.3.1.3 of the Nova Scotia Wholesale and Renewable to Retail Electricity Market Rules . Th...

AI summary IESO Nova Scotia's 10-Year System Outlook (2026-2036) outlines the province's transition to 80% renewable energy and coal phase-out by 2030. The report highlights the need for successful implementation of projects to maintain system adequacy and meet decarbonization targets, while studying impacts of load and generation, including inverter-based resources, to ensure system reliability.

Request IR – 8 - Reference: Exh. N-1, Table 9, and Matter M12592 regarding the ECC Dynamic Line Rating - (DLR) project with a cost of $7 million, including $5.2 million in NRCan funding. - a) Please explain why this project is not included...

AI summary Request IR–8 seeks clarification on the exclusion of the ECC Dynamic Line Rating (DLR) project from Table 9, the significance of the project, and its impact on transmission line interruptions and system operations. The request also explores IESO-NS's views on the purpose and benefits of DLR, including congestion relief, renewable integration, and safety improvements.

- a) Please provide a status update on each of the projects listed in Table 8 and the System Impact Studies being completed, and whether IESO-NS has any updated new large load interconnection requests since the completion of this report in...

AI summary The questions focus on the status of projects in Table 8, their load classifications, system impact analyses, reliability impacts, integration into load forecasts, and implications for system peak, net system requirement, and planning reserve margin.

Response IR - 2 - a) System Impact Studies (SIS) are complete for IRL02 and IRL03. All others are ongoing. - No additional transmission load interconnection requests have been validated since the - publication of the 2026 10 Year System Ou...

AI summary IESO Nova Scotia has completed System Impact Studies for IRL02 and IRL03, with other studies ongoing. No new transmission load interconnection requests have been validated since the 2026 10 Year System Outlook report was published.

NON-CONFIDENTIAL d) All new connections to the Nova Scotia Transmission System must meet applicable reliability standards to connect. This includes maintaining system reliability under expected design conditions over the life of a project....

AI summary The document discusses requirements for new connections to the Nova Scotia Transmission System, emphasizing compliance with reliability standards and the need for a determined tariff class to assess impacts on system reliability. It also mentions the incorporation of IRL-04 into the load forecast and the dependency of impacts on service type and associated generation.

1 Request IR – 19 - 2 Referencing the Transmission Development Project List and Table 9, pdf page 26, IESO Nova - 3 Scotia stated: 6 7 8 9 10 11 12 14 15 16 - 4 Table 9 below lists the transmission system development projects identified by...

AI summary The document requests an explanation of the analysis behind a list of transmission system development projects identified by IESO Nova Scotia, whether these projects were included in NS Power's ACE Plan, details about the terminal points and substations for each project, and the current status of each project.

18 19 20 21 22 23 b) IESO Nova Scotia has not cross-checked the list of transmission projects in the 2026 10 Year System Outlook report with NS Power's 2026 ACE Plan. IESO Nova Scotia notes that many projects in this list are in future yea...

AI summary The IESO Nova Scotia has not verified the list of transmission projects in the 2026 10 Year System Outlook report against NS Power's 2026 ACE Plan, noting that many projects are in future years and may not be reflected until later.

Request IR – 17 - Refer to the 2026 Report Section 5 Transmission Planning, Sub-section 5.1.1 Interconnection - Requirements, page 22, mentioning various studies. - a) Refer to where it states, in reference to inverter-based resources (IBR...

AI summary The document requests specific studies related to inverter-based resources (IBRs) and grid-forming battery energy storage systems (BESS) mentioned in the 2026 Report Section 5.1.1. It asks for identification of the studies, whether they are specific to Nova Scotia or general industry studies, and copies if available. It also seeks information on the timeline for completing a study on interconnection requirements for IBRs.

1 Request IR – 18 - 2 Refer to the 2026 Report Section 5.2.1 Generator and BESS Interconnection, page 23, which - 3 states "there are twenty (20) Interconnection Requests associated with eighteen (18) projects - 4 currently anticipated to...

AI summary The document requests a full list of 20 interconnection requests and 18 associated projects anticipated to connect to Nova Scotia's transmission system before 2030, including project details such as name, generation type, installed capacity, and expected in-service date.

Request IR – 22 - The 2025 Report included several sections that do not appear in the 2026 Report, including but - not limited to various sections under "Generation Resources", "Resource Adequacy", - "Transmission Planning", "Transmission...

AI summary The 2025 Report contains sections not present in the 2026 Report, including 'Generation Resources', 'Resource Adequacy', 'Transmission Planning', 'Transmission Development', and 'Clean Energy Regulations'. The request asks for an explanation of their omission and where equivalent information can be found, including whether NS Power or IESO NS now handles these topics.

RE: M12916 – NSIESO 10-Year System Outlook Report for 2026 SWEB Development is a developer, owner, and operator of renewable energy projects throughout Eastern Canada, headquartered in Halifax, Nova Scotia. The M12916 10-Year System Outloo...

AI summary SWEB Development requests intervenor status in M12916, highlighting the importance of topics such as generation planning, future procurements, renewable electricity targets, and transmission planning as they relate to renewable energy growth in Nova Scotia.

Request IR-16: - Referencing the OATT Transmission Service Queue, on pdf page 24, IESO Nova Scotia stated: - As of June 4, 2026, there are three requests in the Open Access Transmission Tariff (OATT) Transmission Queue.39 - a) The link pro...

AI summary The document references the OATT Transmission Service Queue and highlights a discrepancy in the number of requests listed. As of June 4, 2026, three requests were reported, but the link provided lists only two, prompting a request for clarification on the missing third request.

Request IR-19: - Referencing the Transmission Development Project List and Table 9, pdf page 26, IESO Nova - Scotia stated: - Table 9 below lists the transmission system development projects identified by IESO Nova Scotia which must be com...

AI summary The document requests an explanation of the analysis behind a list of transmission projects identified by IESO Nova Scotia, whether these projects are included in NS Power's ACE Plan, details about terminal points and substations for each project, and the current status of each project.

Request IR-17 Refer to the 2026 Report Section 5 – Transmission Planning, Sub-section 5.1.1 Interconnection Requirements, page 22, mentioning various studies. - a. Refer to where it states, in reference to inverter-based resources (IBRs),...

AI summary Request IR-17 seeks clarification on studies referenced in the 2026 Report regarding interconnection requirements for inverter-based resources (IBRs) and grid-forming battery energy storage systems (BESS). The request asks for identification of specific studies, whether they are Nova Scotia-specific or general industry studies, and the anticipated timeline for completing ongoing studies.

Request IR-20 Refer to the 2026 Report Section 5.4.3 Transmission Development Project List, pages 25-26, referencing the Transmission Development Project List which includes "transmission system development projects identified by IESO Nova...

AI summary The document requests clarification on the basis of transmission development projects listed in Table 9, including whether they are based on recent IESO NS studies, prior NS Power studies, or a combination. It also asks about validation of project needs and responsibility for building upgrades.

Request IR-22 The 2025 Report included several sections that do not appear in the 2026 Report, including but not limited to various sections under "Generation Resources", "Resource Adequacy", "Transmission Planning", "Transmission Developm...

AI summary The 2025 Report included sections not present in the 2026 Report, such as 'Generation Resources' and 'Clean Energy Regulations'. The request asks for an explanation of why these sections were omitted and where equivalent information can now be found, including whether responsibility for these topics has shifted to NS Power or IESO-NS.

7 Reference: Section 5.2.2 Large Load Interconnection Requests; Table 8: Large-Load SIS. - 8 (a) Please provide a status update on each of the projects listed in Table 8 and 9 the System Impact Studies being completed, and whether IESO-NS...

AI summary The document requests an update on the status of large load interconnection projects, details on load classifications, system demand analysis, reliability impacts, load forecast inclusion, and the implications of adding these loads to the forecast. It focuses on the Nova Scotia Independent Energy System Operator (IESO-NS) and its processes.

6 Request IR-3: - 7 Reference: Memorandum of Understanding on Maritime Regional Electricity - 8 Cooperation and System Integration, signed July 23, 2026: - 9 [https://www.gnb.ca/en/org/energy/energy-publications/maritime-regional-electrici...

AI summary This section of the regulatory proceeding requests information about IESO-NS's involvement in a Maritime Regional Electricity Cooperation and System Integration Memorandum of Understanding. It asks about IESO-NS's role, impact on planning and forecasting, implications for Nova Scotia's energy import/export capacity, and whether the MOU's outcomes will be reflected in future planning documents.

3 Request IR-4: - 4 (a) Please confirm whether IESO Nova Scotia is aware of any offshore wind 5 development proposals or initiatives in Nova Scotia (including in relation to 6 the Wind West initiative or any other offshore wind development...

AI summary The request asks IESO Nova Scotia to confirm awareness of offshore wind development proposals, explain the absence of offshore wind in current resource plans, and describe transmission and interconnection planning implications related to offshore wind development.

Request IR-5: Reference : Exh. N-1, Appendix A - a) Please provide the basis for the Maritime Link energy import forecast, including decomposition into its component parts (e.g., NS Block). - b) Please provide the quantity of wind and sola...

AI summary Request IR-5 seeks information on the basis for the Maritime Link energy import forecast and the expected curtailment of wind and solar energy by source for each forecast year.

Request IR-8: - Reference : Exh. N-1, Table 9, and Matter M12592 regarding the ECC Dynamic Line Rating (DLR) project with a cost of $7 million, including $5.2 million in NRCan funding. - a) Please explain why this project is not included i...

AI summary Request IR-8 seeks clarification on the exclusion of the ECC Dynamic Line Rating (DLR) project from Table 9, the significance of the project, and its implications on transmission line interruptions, risk mitigation, and potential benefits such as congestion relief and cost savings. It also requests data analysis, evaluation plans, and comparisons with Ambient Adjusted Rating (AAR) solutions.

October 22, 2026 Nova Scotia Energy Board M12916 IN THE MATTER OF THE PUBLIC UTILITIES ACT - and - IN THE MATTER OF NOVA SCOTIA INDEPENDENT ENERGY SYSTEM OPERATOR'S 2026 10-Year System Outlook Report Thank you for the opportunity to commen...

AI summary The Ecology Action Centre comments on the 2026 10-Year System Outlook Report, expressing concerns about inadequate renewable energy projections, planning margins, and transmission capacity. They argue that current plans fail to meet regulatory limits and urge revisions to resource plans.

s of the report orb) are the responsibility of NSPI. "3As a result, the SBA respectfully submits that the 2026 System Outlook does not provide as comprehensive an assessment as found in prior reports. The SBA acknowledges that IESO Nova Sc...

AI summary The SBA argues that the 2026 System Outlook lacks comprehensiveness due to the division of responsibilities between IESO Nova Scotia and NSPI. It emphasizes the need for coordination, particularly in transmission planning, as NSPI's investments can impact future transmission needs assessed by IESO Nova Scotia.

Delivered by Email Crystal Henwood Regulatory Affairs Officer/Clerk Nova Scotia Energy Board 3rd Floor, 1601 Lower Water Street PO Box 1692, Unit M Halifax, NS B3J 3S3 Dear Ms. Henwood: Re: M12916 – IESO NS– 10-Year System Outlook Report T...

AI summary The Industrial Group submits comments regarding the IESO-NS 10-Year System Outlook Report, highlighting concerns about the Planning Reserve Margin, reliance on third-party projects, Renewable Electricity Standards compliance, and forecasting capabilities. The Group emphasizes the need for greater clarity and continued Board oversight.

5. COORDINATION WITH NSPI'S TRANSMISSION CAPITAL PLANNING The 10YSO Report's Table 9 includes the Transmission Development Project List, which identifies transmission projects that IESO-NS has determined must be completed over the 10YSO ho...

AI summary The document discusses the need for coordination between IESO-NS and NSPI in transmission capital planning, highlighting that IESO-NS has not yet cross-checked its project list against NSPI's 2026 ACE Plan. The Industrial Group (IG) recommends that IESO-NS confirm coordination with NSPI in its next 10YSO filing and reconcile its transmission needs with NSPI's capital plan to avoid duplication or gaps in investment.

CONCLUSION IESO-NS has the opportunity to file rebuttal submissions and may be prepared to accept the IG's recommendations. If so, the IG welcomes those commitments. In the absence of those commitments, the IG respectfully requests that th...

AI summary The IG recommends that IESO-NS provide specific updates and reports in its filings regarding PRM reassessment, project statuses, RES compliance, interconnection requests, coordination with NSPI, and forecasting capabilities. The IG also welcomes IESO-NS's potential acceptance of its recommendations.

Background IESO Nova Scotia ("IESO NS") filed its inaugural 10-Year System Outlook Report (the "Report") with the Nova Scotia Energy Board (the "Board") on June 26, 2026. The Report assesses the province's resource adequacy and transmissio...

AI summary IESO Nova Scotia submitted its first 10-Year System Outlook Report to the Nova Scotia Energy Board, assessing resource adequacy and transmission planning needs from 2026 to 2036. Previously, NS Power's System Operator was responsible for this report under Market Rule 3.4.2.1.

A. Scope of the Report As an inaugural report, IESO NS has re-assessed the content and scope of the report as compared to the reports that have been filed by NS Power. IESO NS explains: The Market Rules prescribe the provision of the 10 Ye...

AI summary IESO NS has re-assessed the scope of the 10 Year System Outlook report, merging or removing sections previously handled by NS Power. Sections like 'Generation Resources' and 'Transmission Planning' are now managed by NSPI, raising questions about coordination between IESO NS and NS Power.

C. Sufficiency of Transmission Planning In addition to the coordination issues with NS Power discussed above, the Report suggests that IESO NS has not taken a sufficiently broad view of its role in driving cost-effective transmission 11 Ex...

AI summary The report highlights that IESO Nova Scotia has not sufficiently evaluated the results of NS Power's DLR project or considered its broader system benefits in transmission planning. The Board is urged to direct IESO Nova Scotia to adopt a more proactive approach in its transmission planning responsibilities.

D. Large Load Service Requests IESO Nova Scotia has received load interconnection requests for ten proposed projects, mainly commercial and industrial, representing 855 MW of potential new load interconnected by 2029.[18](#page-4-4) Other...

AI summary IESO Nova Scotia has received large load interconnection requests totaling 855 MW, which could significantly impact system capacity and reliability. The IESO has not established formal criteria for including these requests in its load forecasts, raising concerns about potential capacity shortfalls. The Consumer Advocate recommends that IESO Nova Scotia review alternative forecasting practices that account for generation and transmission upgrades.