N-1Report
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NON-CONFIDENTIAL 1 TABLE OF CONTENTS 7 Figure 6 - Five-Day Historic Peak Demand and Load Forecast 13 8 Figure 7 - Interruptible Customers and System Load 15 9 Figure 8 - Interruptible Industrial Customer Notifications 15 10 Figure 9 - Emer...
AI summary This report by Nova Scotia Power Incorporated (NS Power) details the company's response to a cold weather event in January 2026, including outage numbers, system information, customer advisories, interruptible load actions, and reserve assistance from neighboring utilities.
2.1.3 Operational Readiness - Building on the lessons learned from the February 4, 2023 extreme cold weather event, a set of - preventative measures was implemented in both Power Production and Energy Delivery. These - measures included ta...
AI summary Following the February 2023 extreme cold event, preventative measures such as infrastructure upgrades, enhanced inspections, and system adjustments were implemented in Power Production and Energy Delivery to improve reliability and grid capacity during extreme cold. Proactive field work by operational groups ensured the system could manage higher loads under challenging conditions.
Distribution - The team reviewed the work completed in response to the February 4, 2023 extreme cold weather - event and confirmed completion. Additionally, the Distribution Planning team used 2025 peak - load data as well as data from the...
AI summary The Distribution team reviewed actions taken after the February 4, 2023 extreme cold event and confirmed completion. Using 2025 peak load data, heavily loaded feeders at risk of tripping during extreme conditions were identified, and protective device settings were validated or updated. Restoration plans were prepared for areas prone to cold load pickup to streamline outage recovery.
Transmission Line - All transmission elements that were out of service due to planned maintenance were returned to - service in advance of the event. DATE FILED: March 6, 2026 Page 7 of 23
AI summary The text notes that all transmission elements out of service for planned maintenance were restored ahead of an event, ensuring reliability. Filed on March 6, 2026, page 7 of 23, it highlights proactive maintenance efforts.
Control Centre Operations - Before the cold weather event, NS Power met with neighbouring utilities to discuss readiness and - align resource availability across the Atlantic area. All Atlantic provinces were forecast to - experience the c...
AI summary NS Power coordinated with Atlantic utilities ahead of a cold weather event, noting Newfoundland and Labrador's frazil ice issue limited energy exports via the Maritime Link. Additional engineering resources were deployed at the Control Centre to manage the event.
Power Production - NS Power maintains and implements its Cold Weather Preparedness plan as outlined in the NERC - Standard, EOP-012-2 "Extreme Cold Weather Preparedness and Operations". Planning and - preparations for the severe weather an...
AI summary NS Power outlines its Cold Weather Preparedness plan aligned with NERC Standard EOP-012-2, detailing pre-event planning, generation fleet hardening, fuel inventory management, and contingency measures like supplemental heating and coal pile management to ensure reliable operations during extreme cold weather.
3.0 JANUARY 24-25, 2026 EXTREME COLD EVENT NS Power served a new all-time hourly integrated average system peak load of 2459 MW at 18:00 on January 25, 2026 (2481 MW instantaneous peak), exceeding the previous hourly integrated average sys...
AI summary NS Power set a new all-time hourly integrated average system peak load of 2459 MW on January 25, 2026, during an extreme cold event, with the grid and assets performing well under the increased demand.
The outages occurring on January 23 and 26 were unrelated to the effects of the cold weather, and only a small portion of the outages on January 24 and 25 were directly related to the cold weather event (see Figure 2). In comparison to the...
AI summary Outages in January 2026 were largely unrelated to cold weather, with fewer customers affected compared to a similar event in February 2023. The impacts of the 2026 cold weather event on customers were significantly reduced due to improvements in manual and automatic load management operations.
1 3.2 Hourly and daily system information posted on OASIS - 2 Below are the hourly average MW flows for January 24 and 25, 2026 for System Conditions - 3 normally posted on the OASIS Daily Report.
AI summary The document discusses the posting of hourly average MW flows for January 24-25, 2026, as part of system conditions information typically found in the OASIS Daily Report. It highlights the availability of detailed operational data for regulatory and planning purposes.
3.4 Details of the Actions Taken in Relation to Interruptible Load
AI summary The section outlines actions taken concerning interruptible load management, though specific details are not provided in the excerpt. The context references regulatory and energy-related entities, suggesting potential discussions on load management strategies and compliance measures.
3.4.1 Interruptible Customers Load management procedures were implemented on January 25, 2026 utilizing interruptible customer capacity. NS Power maintains operating reserves of generation as a North American Electric Reliability Corporati...
AI summary NS Power implemented load management procedures on January 25, 2026, interrupting LIIR customers without telemetry to provide 20 MW of load relief, while those with telemetry provided 50 MW as 10-Minute Reserve for system reliability. Operating reserves are maintained as a NERC-regulated component.
- As per NERC requirements to operate within studied limits and prevent cascading outages, NS - Power prepares and maintains a manual load shedding list of up to 50 percent of system load that - can be shed within 10 minutes to address cap...
AI summary NS Power maintains a manual load shedding list of up to 50 percent of system load, as required by NERC, to prevent cascading outages. Although localized outages occurred on January 25, careful management of available capacity prevented system-wide load shedding.
3.5 Assistance from Neighbouring Utilities - When all available generation resources are in use and load management procedures are in effect, - utilities may request emergency energy assistance from neighbouring areas through established -...
AI summary The text discusses the use of emergency energy assistance between Nova Scotia Power (NS Power) and neighboring utilities, including the Newfoundland System Operator (NLSO) and Maritime Electric (MECL), during periods of supply emergencies. Assistance was provided during specific dates in January when hydroelectric facilities were affected by frazil ice events.
3.6 NSPSO Assistance to Newfoundland and Labrador - As noted above, NS Power provided emergency energy assistance to NLSO on January 21, 24 and - 25. NS Power provided 343 MWh emergency energy assistance to NLSO on January 21 and 113 - MWh...
AI summary NS Power provided emergency energy assistance to NLSO during January 21-25, delivering 343 MWh on January 21, 113 MWh on January 24, and additional energy on January 25. Other utilities continued support until NS-NB transmission capacity was reached at 17:00 on January 25.
3.7 Description of System Stability During the Cold Weather Event - During this cold weather event, all System Operating Limits (SOLs) and Interconnection - Reliability Operating Limits (IROLs) were respected and the Nova Scotia power syst...
AI summary During a cold weather event, Nova Scotia's power system maintained stability by respecting all System Operating Limits (SOLs) and Interconnection Reliability Operating Limits (IROLs). Remedial Action Schemes (RAS) were activated to prevent stability issues. The Onslow South corridor's capacity was increased by 45 MW due to new Battery Energy Storage Systems (BESS), avoiding the need for load shedding.
3.7.1 Transmission / Substation - NS Power's careful management of the available capacity allowed the Company to avoid province- - wide manual load shedding during this event. However, localized rotating feeder outages were - initiated to...
AI summary NS Power's management of available capacity prevented province-wide manual load shedding during the event. However, localized rotating feeder outages were implemented to avoid overloading individual transmission and substation assets.
70W High Street - Rotating feeder outages were initiated at 70W High Street to avoid overload conditions reaching - the protection limit for transmission line L-5545: - Feeder 70W-321 was manually tripped at 10:19 on January 25. - Feeder 7...
AI summary Rotating feeder outages at 70W High Street were initiated to prevent overload on transmission line L-5545. Feeders 70W-321 and 70W-314 were manually tripped, then reconnected after the protection limit for L-5545 was increased, allowing outages to be cancelled.
79V Three-Mile Plain - Loading above design limit was observed on transformer 79V-T1 Rotating feeder outages were - initiated to protect the asset until the winding temperature could be verified in the field. - Feeder 79V-403 was manually...
AI summary Transformer 79V-T1 at Three-Mile Plain exceeded its design load limit, prompting manual feeder outages on 79V-403 and 79V-401. After a technician confirmed the winding temperature was within acceptable limits, outages were canceled, and power was restored to both feeders.
3.7.2 Distribution - The distribution system displayed significantly better performance during this event as compared - to the February 4, 2023 event with respect to repeated outages on downline reclosers. This was - achieved through the a...
AI summary The distribution system showed improved performance compared to a February 2023 event, attributed to post-event actions and proactive measures. A single incident involving recloser 512N-311 in Hedgeville caused 18 trips, affecting 324 customers, but was resolved by adjusting device settings.
3.8 Performance of NS Power's Generation Assets During the Event - The company's generation assets performed well throughout this event, as detailed in the - following sections.
AI summary NS Power's generation assets performed well during the event, as detailed in subsequent sections. The analysis focuses on their operational effectiveness under the circumstances described.
3.8.1 Generation - The decision was made on January 20th to bring Lingan 2 online on January 24th to support the - fleet and reduce the risk of firm customer load shedding throughout the event. The remainder of - the fleet was available an...
AI summary The decision to bring Lingan 2 online on January 24th was made to support the fleet and prevent load shedding. Other generators had planned outages or temporary issues, including maintenance at Wreck Cove 2 and Victoria Junction 2, derating at Tufts Cove 6 due to freezing, and a startup failure at Burnside 2.
3.8.3 Battery Energy Storage Systems (BESS) The NS Power BESS currently consists of two sites (99W Bridgewater, 132H Spider Lake) with a combined output capability of 100 MW for up to four (4) hours. With the reduction of forecast wind gen...
AI summary NS Power's BESS at Bridgewater and Spider Lake provided 230 MWh and VAR support during a tight supply period, aiding system reliability by maintaining voltages during high load.
3.9 Lessons Learned from the February 3-5, 2023 Cold Weather Event NS Power completed post-event analysis and reporting after the February 2023 Cold Weather event. As a result of this analysis, actions were identified for follow up and wer...
AI summary NS Power conducted a post-event analysis following the February 2023 Cold Weather event, leading to system improvements. Actions taken after the event helped the system better withstand extreme cold. In 2023, rotating feeder outages occurred at seven substations, but in 2026, only one substation experienced overloading. Protection settings were reviewed and adjusted, and a new substation is proposed to resolve the L-5545 overloading issue.
DATE FILED: March 6, 2026 Page 22 of 23 1 • The performance of NS Power's generation fleet provided maximum output from 2 all available units. 3 • The addition of BESS was beneficial during the event, providing capacity and 4 reactive powe...
AI summary The document highlights the performance of NS Power's generation fleet, the benefits of BESS during peak load periods, and the absence of firm customer interruptions. It also notes the effective operation of the Labrador Island Link and Maritime Link, localized outages resolved by the engineering team, and coordination with neighboring utilities during an extreme cold weather event.
N-2NSPI (NSEB) RIR 1 to 17
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1 Request IR-1: 2 3 Reference page 6 of the report. 4 5 Please explain what "system adjustments" were implemented after the February 4, 2023, 6 extreme cold weather event. 7 8 Response IR-1: 9 10 Figure 6 of the "Final Outage Report for Fe...
AI summary The document discusses system adjustments made by NS Power following the February 4, 2023, cold weather event and addresses the performance of feeders during the January 2026 cold weather event. It confirms that all adjustments were addressed and that no outages occurred on previously identified feeders during the January 2026 event.
1 field, resolving the issue. This device was originally missing from the list of at-risk devices 2 due to a modelling error. This error has since been resolved. Please see the response to IR 3 12 for more details. 4 5 (c) None of these fe...
AI summary The text discusses a modelling error that led to the omission of a device from the list of at-risk devices, which has since been resolved. It also addresses the performance of substation infrastructure during the January 2026 cold weather event, noting that it performed as expected with only one precautionary rotating outage initiated due to overload concerns.
NON-CONFIDENTIAL Cold Season Rating Protection Limit SCADA Alarm Limit Post 2023 Cold Event 64 MVA 54 MVA Post 2026 Cold Event 64 MVA 61MVA 1 Request IR-11: 2 3 Reference page 18 of the report. 4 5 79V Three-Mile Plain "Loading above desig...
AI summary The document discusses a transformer loading event during a cold weather event, including the transformer's capacity limits, SCADA monitoring capabilities, and the need for a field technician to confirm winding temperatures. The response indicates that SCADA is available at the substation but does not provide real-time winding temperature data for the transformer.
1 Request IR-17: 2 3 (a) Please provide the hourly load forecasts the utility prepared in advance of the 4 January weather forecast that were used for generation dispatch planning. 5 6 (b) Referencing the hourly net load in Figure 5 of the...
AI summary The document includes a request and response related to load forecasts, generation resources, and power supply during a cold weather event in January 2026. The utility provided hourly load forecasts, generation resources, and details about units delayed coming online due to a hydro plant icing issue.
a. Burnside 1 failed to start at 13:10 on January 23, 2026 and was made available again at 13:31 on the same day. b. Burnside 2 failed to start at 12:07 on January 25, 2026 and was made available again at 9:13 on January 26, 2026. (d) The...
AI summary Burnside 1 and Burnside 2 experienced outages on January 23 and 25, 2026, respectively. The text also describes system load and available supply data, noting that Nova Scotia provided emergency energy assistance to Newfoundland during certain periods, which affected generation and reserve levels.
Date: Sun January 25, 2026 HOUR LOAD FORECAST RESERVE REQMT SYSTEM MARGIN PA1 LIN1 LIN2 LIN3 LIN4 TR5 TR6 PT2 TUC1 TUC2 TUC3 TUC6 CT TOTAL IPP TOTAL PT BIO HYDRO TOTAL BESS WIND TOTAL FIRM NB PURCH FIRM NFLD PURCH 21 2287 218 -162 165 148...
AI summary The document presents a detailed table of hourly load forecasts, reserve requirements, and system margins for a specific date, along with various power generation and transmission metrics. It includes data on different power sources such as battery energy storage systems (BESS), wind, and hydroelectric generation, as well as firm purchases from New Brunswick and Newfoundland.
101630NSEB (NSPI) IR-1 to IR-17
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NOVA SCOTIA ENERGY BOARD IN THE MATTER OF: THE PUBLIC UTILITIES ACT - and - IN THE MATTER OF: NOVA SCOTIA POWER INC. (NS Power) Outage Report for January 23-26, 2026, Cold Weather Event
AI summary The Nova Scotia Energy Board is examining Nova Scotia Power Inc.'s outage report for a January 2026 cold weather event under the Public Utilities Act, assessing compliance and reliability during extreme weather conditions.
Request IR-1: - Reference page 6 of the report. - Please explain what "system adjustments" were implemented after the February 4, 2023, extreme - cold weather event.
AI summary The request asks for an explanation of 'system adjustments' implemented by NS Power after an extreme cold weather event on February 4, 2023, focusing on system reliability measures.
Request IR-2: - Reference page 7 of the report. - The report states that data from the February 4, 2023, event was used to "identify heavily loaded - feeders which are subject to protective devices that could be at risk of tripping during...
AI summary Request IR-2 seeks data on feeder performance during the January 2026 cold event, including rated capacities, peak loads, and factors for unidentifed feeders tripping. It references analysis of February 2023 data and asks about discrepancies in feeder identification.
Request IR-3: - Reference page 7 of the report. - With respect to the "substation transformers" and "bulk power substations or assets" that were - anticipated to be at risk for overload, how did the identified infrastructure perform in the...
AI summary Request IR-3 inquires about the performance of substation transformers and bulk power infrastructure during the January 2026 cold weather event, referencing page 7 of the report to assess their resilience to potential overload risks.
Request IR-4: - Reference page 7 of the report. - "Select areas were identified across the Province where restoration is known to be subject to cold - load pickup (very high loading following an outage) and plans were prepared by the Energ...
AI summary The text references page 7 of a report identifying areas in Nova Scotia prone to cold load pickup during power outages, with plans by the Energy Delivery Services Regional Engineering team to streamline restoration. Questions focus on how these areas are identified and why they experience cold load pickup.
Request IR-6: - Reference page 9 of the report. - With respect to the Grid Status Index displayed on the web page: - a) Please explain the procedure that was used to review the status reported on the Index. - b) Was the Index reviewed at r...
AI summary Request IR-6 seeks clarification on the procedure for reviewing the Grid Status Index and whether it is assessed at regular intervals. The inquiry focuses on how the index's status is confirmed or updated, emphasizing procedural transparency and potential changes in grid reliability metrics.
Request IR-7: - Reference page 9 of the report. - "…Large Industrial Interruptible Rider (LIIR) customers were contacted by the Key Accounts team on January 23, 2026…" - Reference page 14 of the report. - "To ensure operating reserves were...
AI summary Request IR-7 seeks clarification on NS Power's January 23, 2026, outreach to Large Industrial Interruptible Rider (LIIR) customers, including whether all LIIR customers were contacted, the timeline of interruptions during a reserve-maintenance event, and the rationale for notifications. The inquiry focuses on load relief mechanisms and telemetry-based interruption practices.
Request IR-8: - Reference page 13, Figure 5, of the report. - The table shows peak Maritime Link imports of just over 250 megawatts in the early evening hours - of January 25, 2026. Given the recent positive test on the Labrador Island Lin...
AI summary Request IR-8 seeks an estimate of future Maritime Link imports under similar conditions to January 25, 2026, and whether the Labrador Island Link's 900 MW capacity would increase NS Power's reserve capacity. The reference is to Figure 5 on page 13, showing 250 MW peak imports on that date.
Request IR-10: - Reference page 18 of the report. - 70W High Street "Rotating feeder outages were initiated at 70W High Street to avoid overload - conditions reaching the protection limit for transmission line L-5545:" … "At 10:41, it was...
AI summary Request IR-10 seeks details on Transmission Line L-5545's capacity during a January cold-weather event, temporary solutions to avoid rotating outages, timeline of actions taken since the issue was identified, and changes to protection settings in 2023. The report references a proposed new substation and adjusted protection settings post-2023.
Request IR-11: - Reference page 18 of the report. - 79V Three-Mile Plain "Loading above design limit was observed on transformer 79V-T1 Rotating - feeder outages were initiated to protect the asset until the winding temperature could be ve...
AI summary The text discusses an incident at the 79V Three-Mile Plain transformer where loading exceeded design limits, prompting feeder outages. A technician confirmed the winding temperature was within acceptable limits, leading to the cancellation of outages. The request seeks information on remote monitoring capabilities, transformer specifications, and the relationship between loading and temperature.
Request IR-12: - Reference page 19 of the report. - "There was one reported case of repeated outages on downline recloser 512N-311, located in - the community of Hedgeville, Pictou County. The recloser tripped and reclosed 18 times during...
AI summary A recloser in Hedgeville, Pictou County, tripped 18 times on January 25, affecting 324 customers. The Engineering team adjusted device settings to resolve the issue. Questions focus on the changes made, their effectiveness, why they weren't implemented earlier, setting determination, and permanence of the solution.
Request IR-13: - Reference page 19 of the report. - "On January 24th and 25th Tufts Cove 6 was derated for periods of time due to freezing instrumentation tubing for a transmitter. An exterior wall mounted heater was repositioned which res...
AI summary Request IR-13 references events at Tufts Cove 6 (freezing instrumentation) and Burnside 2 (fuel control issue) on January 24-25, 2023, and asks whether these events necessitated interrupting LIIR customers between 16:47 and 22:04 on January 25.
Request IR-14: - Reference page 20 of the report. - "Wind generation tracked the forecast trend well. The January 24 day-ahead forecast predicted a steeper generation decline than the two-day-ahead planning forecast on January 23 as shown...
AI summary Request IR-14 asks whether operational issues caused low wind generation on January 25 during a cold-weather event, noting a 367 MW drop in wind production due to declining wind speeds. The request references forecast discrepancies between day-ahead and two-day-ahead planning models.