N-52024-2025 Bates White FAM Audit Report - Redacted
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Figure X-6: Thermal Units' Average Load (MW) 395 Thermal Plant Max Net Capacity Average Load 2024 (MW) Average Load 2025 (MW) Lingan 1 153 86 106 Lingan 2 153 76 46 Lingan 3 148 84 104 Lingan 4 153 82 94 Tufts Cove 1 78 68 34 Tufts Cove 2...
AI summary The text presents data on the average load of various thermal units in Nova Scotia from 2024 to 2025, highlighting the performance of different power plants. It also discusses the economic minimum dispatch levels of these units, indicating how often they were operated at or below this level, which is unusual for baseload units.
X.B.2.a.ii. Availability Factor The second metric we examined was Availability Factor, which NERC defines as the percentage of hours a unit is available over all potential hours of a given period.404 The higher the Availability Factor, the...
AI summary The Availability Factor, defined as the percentage of hours a unit is available over all potential hours, was analyzed for NSPI's thermal units in 2024 and 2025. Most units exceeded industry averages, while Point Aconi and Trenton 5 lagged due to planned outages and seasonal layups.
Figure X-10: Outage Hours of NSPI Thermal Generating Units (by Outage Category) Thermal Plant Planned Maintenance Forced Total Lingan 1 1,756 244 584 2,583 Lingan 2 2,808 0 37 2,845 Lingan 3 2,167 254 215 2,636 Lingan 4 2,388 559 78 3,025...
AI summary Figure X-10 presents outage hours for NSPI thermal generating units categorized into planned, maintenance, and forced outages. The data highlights the total outage hours for each plant and overall, with a note that NERC's GADS does not include biomass plants, leading to the use of alternative comparative technologies for certain units.
Fleetwide, total outage hours (52,260) increased by approximately 3.0 percent from the previous Audit Period.406 Planned outage hours (37,056) increased by 13.4 percent from the previous Audit Period's total of 32,671 hours.407 Forced outa...
AI summary Total outage hours increased by 3.0% during the audit period, with planned outages rising by 13.4% and forced outages decreasing by 22.7%. NSPI scheduled planned outages outside of winter months to avoid peak demand and reduce costs. De-rate incidents on thermal units decreased by 19%, but the average size and duration of de-rates increased.
X.B.2.a.iv. DAFOR The third performance metric we examine is the DAFOR. DAFOR represents the percentage of time that a unit was in forced outage. DAFOR includes both forced outage hours as well as adjusted de-rated hours; it does not inclu...
AI summary The DAFOR metric measures the percentage of time a unit was in forced outage, including adjusted de-rated hours but excluding planned outages. It is compared to the industry average and is used as a proxy for the NERC Equivalent Forced Outage Rate (EFOR). The metric is used to assess the reliability of NSPI's thermal fleet.
Figure X-12: NSPI's DAFOR, by Unit, by Year, Compared to GADS EFOR Standard 416 Thermal Plant DAFOR (2024) DAFOR (2025) GADS EFOR Standard Lingan 1 5.2% 5.8% 11.5% Lingan 2 2.6% 1.2% 11.5% Lingan 3 0.1% 3.2% 11.5% Lingan 4 0.6% 1.8% 11.5%...
AI summary Figure X-12 compares NSPI's DAFOR by unit and year against the GADS EFOR standard. NSPI's thermal fleet generally outperformed the industry average, with Trenton 5 and Tufts Cove 4 being the only units to underperform in both 2024 and 2025.
X.B.2.a.v. Heat Rate The next performance metric we considered was Heat Rate, which is a measure of a generating unit's efficiency. It divides fuel burned (in MMBtu)—or energy "in"—by electricity produced (in kWh)—or 416 For the Tufts Cove...
AI summary The document discusses the Heat Rate as a performance metric for generating units, highlighting its importance in measuring efficiency. It references data for Tufts Cove units and provides information on how NERC does not calculate average heat rates in GADS. The text also references audit reports and training materials.
X.B.2.a.vi. Utilization Factor The last performance metric we reviewed was Utilization Factor ("UF"). NSPI focuses on UF for its plants as a metric that captures the "wear" on its generating units driven by capacity factors, cycling, opera...
AI summary NSPI uses the Utilization Factor (UF) as a performance metric to assess wear on its generating units, influenced by capacity factors, cycling, and operating hours. Actual UFs for 2024 and 2025 largely exceeded forecasts, potentially leading to increased sustaining capital investments and O&M costs.
<sup>426 2022-Evergreen-IRP-Updated-Assumptions-January-2023-Update.pdf, slide 42. 427 2024 FAM Annual Report A2.
AI summary The text references two documents: a 2023 update to the 2022-Evergreen-IRP assumptions and the 2024 FAM Annual Report. These documents are likely related to energy resource planning and generator availability.
Figure X-16: Root Cause Analyses Received or in Progress Generator Status Reviewed by Bates White? Name Port Hawkesbury Complete Yes 2024 BIO LP Extraction CV Rod Failure Burnside Complete Yes 2024 BGT1 Blade Failure Tufts Cove 2 Complete...
AI summary The document lists root cause analyses for various generators, including completed and initiated analyses, with details on the status, reviewing entity, and specific issues identified for each generator.
X.B.3.b.ii. Performance Test Results at Units 2, 4, 5, and 6 During the Audit Period, NSPI conducted performance tests on unit 2 as well as the combined-cycle plant (units 4-6). The performance test for unit 2 tested its output capability...
AI summary During the audit period, NSPI conducted performance tests on Unit 2 and the combined-cycle plant (Units 4-6). The test on Unit 2 was conducted under NERC Standard MOD-025-2 and was the first such test since 2023. Results are addressed in a later section.
X.B.3.b.iii. Start-up issues, resolutions at Tufts Cove 4, 5 There were twenty reported forced outages for failed starts at Tufts Cove Units 4 and 5 in 2025.431 NSPI acknowledged this increase in failed startups, noting that the primary co...
AI summary In 2025, Tufts Cove Units 4 and 5 experienced twenty failed starts due to a recurring generator vent fan fault. NSPI conducted inspections, identified a failed motor as a contributing factor, replaced it, and reported no further failed starts after July 31, 2025.
X.B.3.b.vi. Root Cause Analysis Review We were provided with and reviewed five Root Cause Analyses related to Tufts Cove units. We reviewed NSPI's December 17, 2025 Root Cause Analysis associated with a June 15, 2023 unit trip of Tufts Cov...
AI summary The document reviews five Root Cause Analyses related to Tufts Cove units, focusing on Tufts Cove 3's bearing 8, which experienced high temperature alarms. Despite inspections showing no damage, the bearing continued to show elevated temperatures, prompting further analysis.
X.B.3.c.i. Performance During Audit Period NSPI's seven 33 MW combustion turbines' performance during the Audit Period saw, in some cases, elevated DAFORs in 2024. Performance improved considerably in 2025, as is shown in Figure X-20 below...
AI summary NSPI's combustion turbines showed elevated DAFORs in 2024 but improved in 2025. Availability factors were generally positive, though DAFORs were lower than industry averages. NSPI attributes lower capacity factors to elevated DAFORs.
X.B.3.c.iii. Root Cause Analysis Review We were provided with and reviewed two Root Cause Analyses related to diesel-fired CT units. The first was a December 5, 2025 Root Cause Analysis assessing a March 7, 2024 event at Burnside 1. On tha...
AI summary The document reviews two root cause analyses for diesel-fired CT units. The first analysis relates to a March 2024 event at Burnside 1, where high vibration caused a unit trip, leading to damage in the High Pressure Compressor. The OEM, Wood Group Pratt & Whitney, conducted inspections and laboratory analysis, concluding the failure was due to high cycle fatigue and wear of antifriction coating.
X.B.3.d.i. Performance Test Results During the Audit Period, NSPI conducted real power performance tests at Units 1, 2, and 3. Unit 1 produced MW of gross real power, % above its NPCC declared value of MW, and MW of net real power, % above...
AI summary NSPI conducted real power performance tests on Units 1, 2, and 3 during the Audit Period. Unit 1 and Unit 3 showed real power outputs above their NPCC declared values, while Unit 2 showed outputs below. These were the first tests since 2021.
X.B.3.f.ii. October-November 2024 forced outage On October 26, 2024, Point Tupper was forced offline in an outage that would last 552.37 hours until November 18, 2024.460 NSPI explained that the cause of the outage was a generator trip on...
AI summary Point Tupper experienced a forced outage from October 26 to November 18, 2024, caused by a generator trip due to damage in the rotating brushless exciter assembly. NSPI implemented corrective actions, including cleaning, replacement of components, and updated maintenance schedules. The outage is similar but not identical to a 2022 event, and NSPI has taken additional precautions based on OEM recommendations.
X.B.8. Bates White's 2022-2023 Audit Recommendations In our report for the prior Audit Period, we included seven recommendations regarding power plant performance. We address each as follows. Our first recommendation related to power plant...
AI summary Bates White's 2022-2023 audit report outlines recommendations for NSPI regarding power plant performance, including addressing discrepancies in outage reporting, explaining test results from Tufts Cove 2, and conducting further tests on the PHB biomass unit. NSPI has accepted and partially addressed these recommendations, including conducting additional tests and using a fuel blend for performance evaluation.
ere derated decreased 19 percent from the prior audit period, though the size of the average derate increased by 8 MW (or 11.8%), as did the average duration of the derates (by 59 hours, or by 88.2%). Conclusion X-8: Heat rate performance...
AI summary The audit period saw a 19% decrease in derated capacity, with increased average derate size and duration. NSPI's heat rate performance improved in 2025, with five coal-fired units exceeding industry averages. Utilization factors were higher than forecast, indicating potential increases in capital and O&M costs. NSPI's asset management and outage planning remain effective.
outages are reviewed based on system requirements and economics. Generator concerns and risks are shared and discussed. Representatives from ECC and Asset Management provide questions and/or feedback. - At 10:00 AM, following the Marketing...
AI summary The commitment and dispatch process involves reviewing outages, incorporating updated data into the PortOps model, procuring gas volumes, and generating Day Ahead schedules. These schedules guide real-time dispatch and are shared with multiple departments and entities.
Figure XI-7: Operating Intervals during Audit Period, Lingan 2 Event No. Start Date End Date Number of Days Net Generation (MWh) 1 1/23/24 6:00 PM 2/1/24 1:00 AM 8 21,631 2 2/6/24 8:00 PM 2/14/24 1:00 AM 7 16,765 3 2/21/24 3:00 AM 2/28/24...
AI summary Figure XI-7 presents the operating intervals of Lingan 2 during the audit period, showing the start and end dates, number of days, and net generation for each event. Lingan 2 was used more heavily than in the prior audit period due to large supply deficiencies, with system margins ranging between 80 MW and 275 MW. It was dispatched economically through the PortOps model or Plexos during different periods.