Topic:"System Reliability" in M12247

Planning Environment Updates Clean Electricity Regulations – Alignment to Provincial Policy - Roadmap Item 5 Emitting generation is required to balance wind and ensure grid reliability and to meet customer demand - o Level of use of emitti...

AI summary The document outlines Nova Scotia Power's (NSP) alignment of the Clean Electricity Regulations (CER) with provincial policy, emphasizing the need for emitting generation to balance wind energy and ensure grid reliability. It highlights the 80% renewable energy target by 2030, the role of combustion turbines as fast-acting generation, and the CER's support for thermal fleet flexibility.

Electrification Impacts – T&D System Action Plan Item 2c & Roadmap Item 6 As outlined in Roadmap Item 6 , NS Power continues to monitor electrification and load growth, to reflect these impacts in developed load forecasts for Nova Scotia....

AI summary NS Power is analyzing electrification impacts on its transmission and distribution system, leveraging SCADA and AMI data to refine load forecasts, model system peaks, and identify overloaded equipment. Improved modelling techniques now capture varied peak patterns (morning, afternoon, summer) and enable granular feeder-level load reallocation.

Electrification Impacts – T&D System Action Plan Item 2b & Roadmap Item 6 The 2024 load forecast, the Province's Clean Power Plan and the 2024 10 Year System Outlook provide a clear picture of the generation resources required to serve loa...

AI summary The 2024 load forecast, Clean Power Plan, and 10-Year System Outlook outline generation resource needs. NERC TPL assessment identified three corrective actions, including transformer upgrades and corridor adjustments. Overloaded feeders and transformers are expected but manageable within 5-10 years. Detailed studies were completed in 2024, with planning studies prioritized for 2025.

Thermal investment: The sustaining capital profiles for the thermal units have been updated based on the Evergreen IRP utilization factor approach and the 2030 coal phase out requirements. To maintain resource adequacy while minimizing cap...

AI summary Thermal unit capital profiles were updated using the Evergreen IRP approach and 2030 coal phase-out requirements. Operating restrictions at Trenton 5 limit hours to maintain resource adequacy while minimizing capital investment.

NON-CONFIDENTIAL - 3 The generation profile demonstrates the supportive nature of the thermal generation in meeting - 4 system load when wind resources are in low supply and/or in periods of peak load demand. 2

AI summary The generation profile highlights thermal generation's role in supporting system load during periods of low wind resource availability and peak demand, ensuring reliability when renewable sources are insufficient.

NON-CONFIDENTIAL 1 Request IR-1: 2 3 For the years 2024, 2030 and 2035, please share the total installed generation capacity, and 4 hourly supply-mix, on the: i) winter peak day, and the day prior and following; and on the 5 ii) day of the...

AI summary The request (IR-1) asks for generation capacity and supply-mix data for 2024, 2030, and 2035, including renewable curtailment and demand-side measures. The response notes the Evergreen IRP Model did not model exports, cites the 2023 Load Forecast Report for DSM values, and attributes incomplete data to a cyber incident affecting NS Power's IT systems. Partial data is provided in Attachment 1 and the NS-NB Reliability Intertie model.

NON-CONFIDENTIAL 1 Request IR-4: 23 during P61 overloaded planning events involving the N-1 outage of 345 kV line L 24 8002 (which supplies 103H-T81). This violation was found in both the near- and 25 long-term planning horizons. The P6 pl...

AI summary The text discusses a planning event involving the N-1 outage of a 345 kV line (L-8002) and its impact on the power system, including the overload of a transformer and potential solutions such as adjusting corridor flow limits, increasing overload ratings, or adding a new parallel transformer. The transformer involved is critical to the Metro Halifax power supply.

Generation Resource MW Thermal 1392 CT's 226 Hydro 168 Wind 33 Tidal 0 Biomass 56 Maritime Link 150 Maritime Link Imports 7 Other Imports 51 Battery 0 System Peak (MW) and Time (HE) February 21 @ 9AM

AI summary The table lists Nova Scotia's electricity generation resources with their capacities in MW, including Thermal, Hydro, Wind, Biomass, and imports. It also notes the system peak on February 21 at 9AM. The data highlights the distribution of power sources and system load.

Peak Load Hour 1/9/2035 18:00 Installed Capacity (MW) 1/8/2035 7:00 0 144 550 0 0 106 2 71 573 0 0 0 0 0 575 2021 0.0 1/8/2035 8:00 0 144 550 0 0 318 4 75 705 0 192 0 0 0 50 2039 0.9 1/8/2035 9:00 0 144 750 0 0 294 5 75 421 4 175 0 0 0 300...

AI summary The document presents a table detailing installed capacity and load data for various times on January 8, 2035, leading up to the peak load hour on January 9, 2035, at 18:00. It includes metrics such as demand, generation, and capacity across different time intervals.

s). The currently available modeling work provides an appropriate representation for the current planning environment until the completion of the NSIESO's first IRP. [NS Power Reply Submission, p. 7] The Board shares Synapse's concerns abo...

AI summary The Board acknowledges concerns raised by Synapse, Energy Storage Canada, Natural Forces, and Solar Nova Scotia regarding NSIESO's IRP modeling, including Mersey hydro system rehabilitation, load forecasting, and NS-NB Intertie impacts. The Board directs that policy factors like 'sustainable prosperity' be considered in the IRP process, with Solar Nova Scotia's DER Roadmap comments addressed in matter M12177.

Request IR-4: - On page 20, NS Power stated that the Reliability Tie (Stage 1 Onslow to Salisbury) has a future - potential firm import capacity of 100 MW. However, NS Power has also stated that the Reliability - Tie is essentially a backu...

AI summary NS Power claims the Reliability Tie (Stage 1) has 100 MW future potential firm import capacity but clarifies it serves as a backup to the existing 345 kV tie line, not for increasing imports. Questions seek clarification on reconciling this statement and Stage 2's capacity.

1 Request IR-1: Reference: Extent of new modeling in support of Action Plan update. - 2 a. State whether NSP conducted any new capacity expansion or production cost 3 modeling as part of this IRP Action Plan and Roadmap update. - i. If yes...

AI summary The document requests information on NSP's new modeling for the IRP Action Plan update, including capacity expansion, production cost modeling, compliance with Clean Electricity Regulations, use of recent load forecasts and DSM Plan, and reference to Matter M12217.

17 Request IR-2: 18 19 RE: Action Plan Item 2b 20 21 Please provide a description of data that NS Power monitors, or anticipates monitoring, to 22 understand trends in electrification impacts. If available, please provide those data. For e...

AI summary NS Power requests data on electrification impacts, including interconnection and upgrade requests, overloaded facilities, and mitigation efforts. The request seeks insights into trends related to grid infrastructure and system reliability.

13 Request IR-5: - 17 (a) Please provide an update on the status of the fast-acting generation capacity. - 19 (b) What is the role of the NSIESO in planning and procuring the fast-acting generation 20 resources? - 22 (c) Is the fast-acting...

AI summary Request IR-5 seeks updates on fast-acting generation capacity status, NSIESO's role in planning/procuring resources, delays in timelines, gas turbine contract delivery periods, market assessments, and NS Power's evaluation of BESS vs fast-acting generation investments. Questions focus on scheduling, procurement processes, market dynamics, and infrastructure planning.

(902) 422-9663 [[email protected]](mailto:[email protected]) WWW.NATURALFORCES.CA - 5. What factors, related to the technical capabilities of an energy resource, affect its selection by the model? For example, does a resource's ramp...

AI summary The text includes three questions from a regulatory proceeding regarding the Integrated Resource Plan (IRP) model. It asks about technical factors influencing energy resource selection (e.g., ramp-rate, inertia support), projected changes in ancillary service needs (load variation, frequency regulation) through 2035, and whether the IRP model accounts for Synchronous Condensers.

C ONTENTS 1. SUMMARY OF FINDINGS 2. Background 3 3. 2025 Action Plan Update 6 3.1. Changes to Electricity Planning Environment 7 3.2. Progress Updates on Action Plan Items for 2024/2025 to Date 8 3.3. Progress Updates on Roadmap Items for...

AI summary The document provides a summary of findings from a regulatory proceeding, outlining key points such as the lack of justification for 600 MW of new CTs by 2030, the need for a new Evergreen IRP, and discussions on reliability tie and Mersey matters.

The Reliability Tie provides resource adequacy insurance in addition to reliability benefits While it is reasonable that NS Power did not directly incorporate the modeling results used in the Reliability Tie application (M12217) into the I...

AI summary The Reliability Tie offers resource adequacy insurance and reliability benefits. NS Power's modeling in M12217 was not fully integrated into the IRP Update, and Synapse's evidence highlights gaps in the model's comprehensiveness, including outdated load forecasts and cost trends for combustion turbines (CTs). The Tie's ability to allow 100 MW of incremental firm import was excluded from primary cases, affecting 2030 CT resource needs.

d peak building electrification options. - 5. Avoided Costs of Demand-Side Management (DSM): NSPI stated that it would update the avoided costs of DSM, targeting completion before the end of 2023. NSPI also identified 11 Roadmap items that...

AI summary NSPI plans to update DSM avoided costs by 2023 and monitor factors like wind integration and fuel costs. Synapse criticized the exclusion of Atlantic Loop from the Preferred Plan, emphasized Reliability Tie development, supported solar/wind procurement, advocated for accelerated battery storage, and urged updated capacity accreditation studies for IRP accuracy.

Table 1. Related Documents and Efforts Release Date Document Description June 30, 2023 2023 10-Year System Outlook Based on 4/30/23 load forecast update and the Evergreen IRP modeling results August 8, 2023 2023 IRP Based on modeling condu...

AI summary The document outlines a series of related documents and efforts in Nova Scotia's energy sector, including system outlooks, integrated resource plans, electrification reports, and reliability studies. These documents are based on load forecasts and modeling updates conducted over several years, with ongoing stakeholder engagement and revisions to project scopes.

2025 10-Year System Outlook, pages 45-46, "The capacity additions and retirements are in alignment with the CE1-E1-R2 Evergreen IRP scenario and the Province of Nova Scotia's 2030 Clean Power Plan." from New Brunswick, the current relative...

AI summary The 2025 10-Year System Outlook report shows a 25% reserve margin by 2029/2030, indicating a 119 MW surplus, but NS Power has not adjusted its capacity plans. The report does not address potential impacts of battery storage, ELCC parameter changes, or the Net Zero Atlantic study on 2030 resource needs, despite these factors possibly reducing peak load forecasts.

Table 2. New CT Capacity as Percent of Firm Peak Load in IRP, 10-Year System Outlook reports and Reliability Intertie modeling 2030 Nameplate Capacity New CT Capacity as Percent of Firm Peak 2023 IRP 20% 2023 System Outlook 29% 2024 System...

AI summary Table 2 presents the percentage of new combustion turbine (CT) capacity relative to firm peak load in various planning documents, including the Integrated Resource Plan (IRP) and 10-Year System Outlook reports, as well as Reliability Intertie modeling. The data shows varying percentages from 20% to 29% across different years and models.

4.3. Reliability Tie Completion of the Reliability Tie goes a long way towards ensuring Nova Scotia can reliably comply with 2030 coal retirements without necessarily going above 300 MW of new CTs by that year. New Brunswick is completing...

AI summary The Reliability Tie project enhances Nova Scotia's ability to meet 2030 coal retirement targets without exceeding 300 MW of new CTs. New Brunswick's transmission work allows 100 MW of firm imports, supported by battery storage, ELCC updates, and demand response. The 2025 10-Year System Outlook shows a 25% reserve margin, suggesting current 450 MW CT levels suffice for resource adequacy.

Prepared for the Nova Scotia Consumer Advocate August 18, 2025 John D. Wilson, Grid Strategies LLC NS Power's 2025 IRP Update is generally reasonable, but the Board should direct NS Power to initiate work – to be completed by the NSIESO –...

AI summary The 2025 IRP Update by NS Power is deemed reasonable but requires the Board to mandate immediate IRP modeling by NSIESO, prioritizing fast-acting generation procurement. Urgency is emphasized to avoid delays in system planning during administrative transfers.

1. Update to Evergreen IRP The NSIESO expects to assume responsibility for system planning, transmission interconnection, and energy and capacity procurement functions in Q4 2025. 1 Synapse Recommendation 1 appropriately points to the need...

AI summary The document outlines updates to the Evergreen Integrated Resource Plan (IRP), emphasizing NSIESO's upcoming role in system planning by Q4 2025. It highlights the need to evaluate Mersey's economic prudence, complete ELCC studies, and align the IRP with the Reliability Tie project. The Board is urged to expedite IRP modeling to avoid delays, even as NS Power transitions responsibilities to NSIESO.

nergydome.com); and thermal (e.g., www.antora.com). 1 For further information, please visit[: www.energystoragecanada.org](http://www.energystoragecanada.org/) 3. ESC notes that on the day of peak demand in 2030 (8 January), it could be ex...

AI summary Energy Storage Canada (ESC) highlights that fossil fuel generation could constitute 25-48% of hourly supply during peak demand in 2030, conflicting with provincial energy policies. ESC urges the Board to incorporate 'energy security' principles into Integrated Resource Plan (IRP) modeling, alongside existing criteria like cost and reliability.

not allow for delay of critical system planning work to begin while the NSIESO transfer process is completed.[3](#page-3-2) DATE FILED: September 4, 2025 Page 4 of 19 Synapse Submission, Re: Comments on Nova Scotia Power's 2025 Integrated...

AI summary The transition of IRP responsibilities to NSIESO raises concerns about potential planning gaps during the transfer. Submissions highlight uncertainty in the transition timeline and the need for continuous system planning. NSIESO has initiated steps like establishing a Board of Directors and filing its first Expenditure and Revenue Requirement application (M12412).

those activities, such that there is no gap in work required to set-up the NSIESO for success. Namely, NS Power will continue to advance work on the Effective Load Carrying Capacity (ELCC) study, as well as continued participation in the N...

AI summary NS Power highlights ongoing efforts to prepare the NSIESO for success, including the ELCC study and participation in the Net Zero Atlantic Hybrid Peak study. It also references the Evergreen IRP and PLEXOS modeling from previous proceedings, such as the Reliability Intertie application (M12217), to support its planning assumptions and modeling accuracy.

DATE FILED: September 4, 2025 Page 9 of 19 2023 Load Forecast Report (M11108), April 28, 2023, Figure 2: Historical and Predicted Annual System Peak, page 8. 2023 10 Year System Outlook Report (M11221), June 30, 2023, Figure 19: NS Power 1...

AI summary The document discusses the need for additional firm capacity, particularly fast-acting generation, to maintain the target PRM in Winter 2029/30 and support the transition off coal as outlined in the 2025 10-Year System Outlook Report. It references the Evergreen IRP and the Province's Clean Power Plan, and notes that NS Power supports the procurement of 300 MW of fast-acting generation.

e transition. NS Power did not agree with some of the above concerns and other submissions made by the participants about items which they claimed were not incorporated into the Evergreen IRP Update. In addition, NS Power would like to rei...

AI summary NS Power disputes concerns about the Evergreen IRP Update, citing PLEXOS modeling from prior proceedings like the Reliability Intertie application (M12217). They argue that modeling reflects updated forecasts, regulations, and hybrid-peak heating impacts, remaining valid until NSIESO completes its first IRP.