Topic:"Planning Reserve Margin" in M12916

3.3.1 Planning Reserve Criteria The Planning Reserve Margin (PRM) is intended to maintain sufficient resources to reliably serve firm customers during periods of grid stress. Unit forced outages, higher than forecast demand, and lower than...

AI summary The Planning Reserve Margin (PRM) is a critical criterion for ensuring reliable power system operation during grid stress. IESO Nova Scotia must comply with NPCC reliability criteria, which require a loss of load expectation (LOLE) of no more than 0.1 days per year. A 20% PRM target was confirmed as appropriate in the 2020 Integrated Resource Plan (IRP).

3.3.2 Load and Resources Overview The 10-year load and resources outlook in [Table 4](#page-18-0) demonstrates whether the system's firm capacity meets the forecast firm peak plus the PRM requirement of 20% for each year over the planning...

AI summary The 10-year load and resources outlook shows that firm capacity must meet the forecast firm peak plus a 20% PRM requirement. Firm peak demand is projected to increase from 2,367 MW to 2,628 MW, with capacity additions and retirements based on forecasts.

Fast-Acting Generation The Fast-Acting Generation addition in 2029/2030 represents the firm fast-acting generation discussed in Section [3.2.4](#page-13-5) . The 450 MW quantity is required to meet the 20% PRM target in 2029/2030.

AI summary The Fast-Acting Generation addition of 450 MW in 2029/2030 is necessary to achieve the 20% PRM target, as outlined in Section 3.2.4.

Planning Reserve Margin The PRM target of 20% is met from 2026/2027 through to 2033/2034, but currently falls below the target in the final two years of the outlook, indicating additional firm capacity will be required in the outer years....

AI summary The Planning Reserve Margin (PRM) target of 20% is met from 2026/2027 through 2033/2034, but falls below the target in the final two years, indicating a need for additional firm capacity. The 2026 Integrated Resource Plan (IRP) will determine the optimal types, quantities, and timing of new resources to meet PRM in all years.

- b) If not, please describe the scope, timing, and expected in-service dates of any such expanded or accelerated procurement, and explain how it would affect the firm capacity additions, Planning Reserve Margin, and synchronous condenser...

AI summary The text requests clarification on the scope, timing, and impact of potential expanded or accelerated procurement on firm capacity additions, Planning Reserve Margin, and synchronous condenser requirements, as well as its effect on the battery storage capacity target under the Clean Power Plan.

NON-CONFIDENTIAL b) Table 8 lists load projects which have requested a transmission interconnection study from IESO Nova Scotia. Tariff class is determined by the Load Serving Entity and this directly informs whether portions of the load c...

AI summary The document outlines that IESO Nova Scotia does not analyze how changes in system demand impact individual tariff classes, as this is the responsibility of Load Serving Entities. It also notes that the 2026 Integrated Resource Plan will assess the impact of adding large loads to the system, while the 20% planning reserve margin target is not expected to change.

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.

Request IR – 7 - Please describe IESO Nova Scotia's contingency plan to meet projected system load, as well as - maintain system reliability and NPCC compliance, if IESO Nova Scotia has not put 250 MW of - battery storage in-service by 202...

AI summary IESO Nova Scotia explains that even without the 250 MW battery storage in-service by 2029/2030, the system can still maintain a 20% planning reserve margin due to other resource additions and a forecasted reserve margin surplus of 108 MW.

Response IR - 8 - a) The firm capacity values in Table 3 and Table 4 are based on Effective Load Carrying Capacity (ELCC) for variable renewable resources, like wind and solar, and energy limited resources, like batteries and demand respon...

AI summary The response discusses the calculation of firm capacity values for different types of energy resources, distinguishing between variable renewable resources (like wind and solar) and dispatchable thermal resources. It explains how Effective Load Carrying Capacity (ELCC) is used for variable resources and installed capacity for thermal resources, and how marginal ELCC decreases as resource penetration increases.

Request IR – 11 - Referencing IESO Nova Scotia's 10-Year Load and Resource Outlook: - Pdf page 18 states that the PRM will fall below the 20% target in the final two years of the - outlook, which indicates that additional firm capacity wil...

AI summary The text references the IESO Nova Scotia's 10-Year Load and Resource Outlook, noting that the Installed Capacity Planning Reserve Margin (PRM) is projected to fall below the 20% target in the final two years, indicating a need for additional firm capacity. It requests confirmation on whether the 2020 Integrated Resource Plan (IRP) analysis could satisfy the Loss of Load Expectation (LOLE) criteria with a PRM below 20% and a reproduction of Table 4 showing demand-side management (DSM) forecasts.

Response IR - 11 - a) For Winters 2030/2031 to 2035/2036 the resource additions shown in Table 4 match those from 2023 Evergreen IRP scenario CE1-E1-R2. With the updated 2026 load forecast, the load and resource table now shows the PRM dro...

AI summary The resource additions for Winters 2030/2031 to 2035/2036 align with the 2023 Evergreen IRP scenario CE1-E1-R2. However, with the updated 2026 load forecast, the PRM is expected to drop below 20% in 2034/2035 and 2035/2036. The IESO will procure resources as needed to maintain the 20% PRM, with any required resources identified in the 2026 IRP and future System Outlook reports.

NON-CONFIDENTIAL 5 Interruptible Load (129) (135) (142) (141) (140) (140) (139) (139) (138) (138) 6 Firm Peak (with DSM) 2,367 2,391 2,407 2,422 2,453 2,480 2,513 2,550 2,592 2,628 7 Required Capacity 8 Required Reserve (20%) 473 478 481 4...

AI summary The document presents a table detailing the capacity planning for the energy system, including existing and new resources, retirements, and reserve margin calculations. It outlines the changes in firm capacity and reserve margin percentages for various years, reflecting the impact of new renewable energy additions, retirements of older facilities, and demand response contributions.

Request IR – 12 - Please provide graphs showing historical and predicted annual system peak and annual net - system requirement values for review, including the past 10 years and next 10 years, similar to - Figures 1 and 2 in the 2025 10-Y...

AI summary The request asks for historical and predicted annual system peak and net system requirement values for the past and next 10 years, similar to figures in the 2025 10-Year System Outlook. The response refers to the 2026 Load Forecast Report and notes that certain loads are not included in the energy requirement calculations.

Request IR – 1 - a) How will the results of the current Integrated Resource Plan (IRP) that is underway be reflected in, or incorporated into, future 10-Year System Outlook (10YSO) Reports? - b) Where differences arise between the conclusi...

AI summary The response to Request IR-1 explains that the 2026 Integrated Resource Plan (IRP) will be the central planning scenario for future 10-Year System Outlook (10YSO) Reports. The IRP will be the primary basis for resource procurement decisions, while the 10YSO serves as an annual checkpoint to ensure alignment with planning assumptions and reserve margin targets.

Request IR – 2 - Reference: 2026 10-Year System Outlook Report, 3.3.2 Load and Resources Overview, Table 4: - IESO-NS 10-Year Load and Resource Outlook, page 18. - Table 4 identifies resources including fast-acting generation, firm imports...

AI summary The document requests the IESO-NS to describe contingency plans and alternative measures if the procurement, development, or in-service dates of necessary resources, such as fast-acting generation and battery storage, are delayed. This is in the context of retiring coal resources and ensuring firm capacity needs are met.

Response IR - 2 - the in-service dates for the identified projects is delayed the corresponding unit retirement will similarly need to be delayed until replacement capacity is online and reliable operation is established. The only scenario...

AI summary The response discusses potential delays in project in-service dates and the need to delay unit retirements until replacement capacity is operational. It highlights that capacity shortfalls could occur if load growth exceeds forecasts, but the 20% Planning Reserve Margin is maintained to address unanticipated demand variations.

Response IR - 4 a) The 2025 10-Year System Outlook used ELCC values from the 2019 E3 Planning Reserve Margin and Capacity Value Study. Please see Appendix 6 of the study for average and marginal ELCC values for all penetration levels on Pa...

AI summary The response discusses the use of Effective Load Carrying Capability (ELCC) values in the 2025 and 2026 10-Year System Outlooks, referencing studies from 2019 and 2026. It provides citations to the studies and their respective appendices for further details.

Response IR - 6 - a) The 95% ELCC value for hydro is based on the 2019 ELCC [1](#page-10-0) . The value for domestic hydro is shown on page 265/487 of the referenced PDF. E3 reviewed theas part of the 2026 ELCC study, and the values used i...

AI summary The response discusses the 95% ELCC value for hydro, noting its basis in the 2019 ELCC study and consistency with the 2026 10-Year System Outlook. Mersey Hydro is assigned a lower ELCC due to a higher forced outage rate, with the value based on the NERC EFOR stat and a five-year average from 2021 to 2025.

Response IR - 9 - a) The basis for the delivery timing assumption of Winter 2028/2029 is the forecast commercial operation date of 2028 for NB Power's Renewables Integration Grid Security (RIGS) Project. [1](#page-15-0) Commercial operatio...

AI summary The response outlines the basis for the delivery timing assumption of the Winter 2028/2029 planning period, which is tied to the commercial operation date of NB Power's RIGS Project. It also notes that even without the 100 MW firm import, the Planning Reserve Margin would still meet the 20% target.

NON-CONFIDENTIAL 2 Defends the 2026 Depart Casting 2.2.1 D1 - Refer to the 2026 Report Section 3.3.1 Planning Reserve Criteria, page 16, which states that

AI summary The text references the 2026 Report Section 3.3.1 Planning Reserve Criteria, page 16, which is part of a discussion on planning reserve margin criteria in the context of a regulatory proceeding.

- "NS Power studied the appropriate calculation of the PRM in Nova Scotia as part of the 2020 - IRP, which confirmed that a 20% PRM target was appropriate for long-term planning. IESO - Nova Scotia continues to use the 20% PRM target." - a...

AI summary The text discusses the 20% PRM target used by Nova Scotia for long-term planning, as determined by the 2020 IRP. It also includes a request for IESO NS to consider conducting an updated study on the PRM and who would be responsible for it.

Request IR-11: - Referencing IESO Nova Scotia's 10-Year Load and Resource Outlook: - Pdf page 18 states that the PRM will fall below the 20% target in the final two years of the outlook, - which indicates that additional firm capacity will...

AI summary The text references the IESO Nova Scotia's 10-Year Load and Resource Outlook, noting that the PRM will fall below the 20% target in the final two years, requiring additional firm capacity. It also requests confirmation on the 2020 IRP analysis regarding NPCC LOLE criteria and reproduction of Table 4 showing DSM's impact on system peak reduction.

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.

specially for beyond 2032, where they are based on projections from six years ago). The Ecology Action Centre would ask the regulator to require the system operator to revise their resource plans to: - 1. Demonstrate full compliance, with...

AI summary The Ecology Action Centre requests the regulator to require the system operator to revise resource plans, including compliance with RES and PRM targets, accelerating regional planning for import capacity, and piloting long-duration energy storage. This is part of a submission by Chris Benjamin.

2. Resource Adequacy Risks and Contingency Planning The System Outlook forecasts a reserve margin surplus in every year through Winter 2033/2034. 8 However, that surplus depends on many projects being completed on schedule. A significant n...

AI summary The System Outlook forecasts a reserve margin surplus through Winter 2033/2034, but this depends on timely project completion. The SBA argues that the surplus may not be sufficient if multiple projects are delayed, and criticizes the lack of contingency planning by IESO Nova Scotia. NSPI also questions the contingency planning approach.

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.

1. PLANNING RESERVE MARGIN The PRM is important for ensuring sufficient resources to reliably serve firm customers and is particularly important for interruptible customers who may be called upon for interruption to address any inadequacy...

AI summary The Planning Reserve Margin (PRM) is crucial for ensuring resource adequacy, especially for interruptible customers. NSPI historically used a 20% PRM, but a recent study suggests a re-evaluation is needed due to the increasing use of variable renewable resources. IESO-NS plans to conduct a PRM re-assessment in the future, though no timeline has been provided. The Industrial Group (IG) agrees with the timeline and recommends confirming it in upcoming filings.

2. CONTINGENCY PLANNING FOR KEY RESOURCE ADDITIONS The 10YSO Report confirms that overall, "the Nova Scotia system is anticipated to see a net increase in installed capacity of 2,804 MW over the next 10 years, providing a net increase of 3...

AI summary The document discusses the anticipated increase in installed capacity in Nova Scotia's electricity system over the next decade, highlighting the need for contingency planning due to uncertainties in the timing of resource additions. The Industrial Group (IG) notes that resource adequacy conclusions depend on external factors outside IESO-NS's control.

4. LARGE-LOAD INTERCONNECTION REQUESTS Table 8 of the 10YSO Report identifies several large-load interconnection requests under study, representing a potentially significant impact on peak demand, especially when combined. IESO-NS has conf...

AI summary The text discusses large-load interconnection requests and their potential impact on peak demand and system reliability. IESO-NS has only studied one project, IRL04, and has not analyzed others. The Industrial Group (IG) recommends that the Board direct IESO-NS to report on the status of these requests in future filings.

6. INDEPENDENT DEMAND AND RESOURCE ADEQUACY FORECASTING The More Access to Energy Act provides that one of IESO-NS's objects is to "forecast electricity demand and the adequacy and reliability of electricity resources for the Province for...

AI summary The document discusses the need for IESO-NS to develop independent demand and resource adequacy forecasting, as required by the More Access to Energy Act . It highlights concerns about continued reliance on NSPI's load forecasts and suggests that IESO-NS should report on its intentions and timeline for developing independent forecasting capabilities in its next 10YSO filing.

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.

f transmission projects that IESO NS must consider when optimizing customer investments in forward-looking system planning. This lack of coordination could negatively impact system planning generally. In its 2026 ACE Plan Decision, the Boa...

AI summary The document highlights a lack of coordination between NS Power, IESO NS, and the Province in planning for decarbonization and transmission projects, which could impact system reliability and the achievement of 2030 targets. The Board emphasized the need for closer collaboration, but IESO NS has not yet responded to this directive.

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.