Topic:"Environmental Compliance" in M12665

other assumptions regarding NSPI's units operation (such as alternative fuel blends and associated emissions); (5) purchased power costs; and (6) the topology and capacity of the transmission system. To account for future changes in the No...

AI summary This section discusses how NSPI uses the PLEXOS model to forecast fuel requirements, account for environmental constraints, and adjust for events like the Certificate of Variance and cyber events that impacted system availability.

III.B.2.a. Inputs and Assumptions used with PLEXOS in Fuel and Purchased Power Forecasting To accurately simulate the operation of the NSPI system, including accurate modelling of the transmission security constraints limiting the economic...

AI summary The document details the inputs and assumptions required for PLEXOS modeling in fuel and purchased power forecasting for NSPI. It includes load forecasts, transmission characteristics, fuel prices, generating unit data, operating costs, and emission assumptions.

III.B.2.b. Environmental Considerations in Unit Commitment and Dispatch Forecasting NSPI is subject to air quality regulations that dictate its fleetwide emissions of SO2, NOx, mercury, and GHGs. NSPI's F&PP forecasts incorporate these lim...

AI summary NSPI must comply with air quality regulations, which influence its unit commitment and dispatch forecasting. It uses tools like PLEXOS and PortOps to model emissions constraints, manage fuel blends, and incorporate OBPS cost adders for GHG emissions. Emissions compliance is reviewed by multiple teams, and adjustments are made to ensure adherence to environmental regulations.

III.B.2.c. Estimation Tracking and Verification of Emissions Compliance at NSPI The NSPI Environmental Services team estimates emissions monthly. Adjustment to SO2 emissions occurs following month end if there is an instrumentation failure...

AI summary NSPI's Environmental Services team estimates emissions monthly, with adjustments made for instrumentation failures or QA/QC issues. Emissions are verified annually by a third-party by March 31 of the following year.

III.B.2.d. Safeguards to prevent errors in past emissions data entering PLEXOS Emissions estimates are made available to Fuels Planning the month following based on the best available information. The data is finalized and verified by a th...

AI summary The document outlines procedures to prevent errors in past emissions data from entering PLEXOS. Emissions estimates are verified by third parties, compared regularly, and undergo quality assurance checks. If discrepancies or concerns arise, they are escalated to management for resolution.

132 NSPI 2025 Annual FAM Report, A-2. 133 Q4 2024 FAM Report, 3(3); Q4 2025 FAM Report, 3(3). 134 Q4 2024 FAM Report, 2(3); Q4 2025 FAM Report, 2(3). explained later in this chapter, NSPI changed the fuel blends at several solid fuel-fired...

AI summary NSPI adjusted fuel blends at solid fuel-fired plants in 2024 to comply with sulfur emissions limits, leading to increased coal consumption. A certificate of variance in 2025 allowed higher SO2 emissions, enabling greater use of solid fuel. Additionally, the OBPS regime favored solid fuel over natural gas, further increasing consumption. Actual solid fuel consumption was higher than forecasted in most months of the audit period.

IV.B.3. Solid Fuel Sources and Types Several of NSPI's thermal generators burn blends of solid fuel, including various types of coal and petcoke. (We explain below NSPI's approach to blending fuels and the relative benefits of each type of...

AI summary NSPI uses a mix of solid fuels, including coal and petcoke, with most being imported. Fuel consumption varies seasonally, peaking in winter. Coal types differ in heat content, emissions, and ash production, affecting efficiency and compliance with environmental regulations.

Instances of Lost Fuel NSPI reported six instances of lost solid fuel. All six were related to coal escaping from rail car doors during transportation on the Point Tupper-Trenton rail route. NSPI explained that it recovered almost the enti...

AI summary NSPI reported six instances of lost solid fuel due to coal escaping from rail cars during transportation on the Point Tupper-Trenton rail route. The coal was recovered and returned to Bear Head, with cleanup costs passed to FAM customers. NSPI also implemented rainwater management systems and adjusted capacity limits at Point Tupper Marine Terminal to prevent coal pile sloughing.

Petroleum Hydrocarbon Release at Sydney Coal Railway Train Maintenance Facility In this section, we provide details regarding the Sydney Coal Railway train maintenance facility. NSPI confirmed that the costs associated with this section we...

AI summary The document discusses a petroleum hydrocarbon release at the Sydney Coal Railway train maintenance facility, detailing environmental assessments conducted by NSPI to determine the source of contamination. The assessments found evidence of contaminants in soil, groundwater, and surface water, leading to recommendations for further investigation.

X.B.7. Environmental Matters NSPI is subject to provincial regulations and laws that govern the allowable emissions from its generating facilities. These include both fleetwide limits and unit-specific limitations. NSPI is required to comp...

AI summary NSPI must comply with provincial regulations on emissions from its generating facilities, including annual limits for SO2, NOx, Hg, and CO2 at both fleetwide and unit-specific levels. Figure X-31 outlines these fleetwide limitations for SO2, NOx, and Hg.

<sup>496 Air Quality Regulations, made under sections 25 and 112 of the Environment Act S.N.S. 1994-95, c. 1 O.I.C. 005-87 (February 25, 2005, effective March 1, 2005), as amended, Schedule C. The mercury limitation allows NSPI to apply...

AI summary NSPI is subject to Air Quality Regulations and Greenhouse Gas Emissions Regulations, which impose mercury and GHG emission limits. The mercury limit allows an additional 10 kg of credits annually, effectively capping emissions at 45 kg/year. NSPI's compliance with these regulations is discussed, along with applicable limitations.

Figure X-32: NSPI's Fleetwide CO2 Equivalent Emissions under Nova Scotia's Greenhouse Gas Emissions Regulations 497 Compliance Period CO2e (mega tons) 2021-2024 27.5 (cumulative total) 2025 6 Second, NSPI was also subject to the Output Bas...

AI summary NSPI's fleetwide CO2 equivalent emissions under Nova Scotia's Greenhouse Gas Emissions Regulations are shown, with 27.5 mega tons from 2021-2024 and 6 mega tons for 2025. NSPI is also subject to the Output Based Pricing System (OBPS), which replaced Cap-and-Trade in 2023 and sets performance standards for individual generators.

X.B.7.c. NSPI's Compliance with Opacity and Stack Limitations As shown in Figure X-36 below, NSPI exceeded opacity limits at its generating stations 120 times during the Audit Period, up from 52 in the prior Audit Period.511 Most of those...

AI summary NSPI exceeded opacity limits at its generating stations 120 times during the Audit Period, with most exceedances at Lingan. Two instances of non-compliance with instack particulate limits were recorded at Trenton 5 in 2024. NSPI conducted maintenance to address these issues and reported no further exceedances.

Report, tab 1(3). 547 Q4 2025 FAM Report, tab 1(3). Conclusion X-30: Sustaining capital investments totaled $ million in the Audit Period, a decrease of 13.6 percent from the prior Audit Period. Conclusion X-31: NSPI personnel was highly c...

AI summary The audit period saw a 13.6% decrease in NSPI's sustaining capital investments. NSPI complied with SO2 limits but exceeded mercury emissions in 2025, with discrepancies in reporting. NSPI met GHG emissions regulations, though there is a discrepancy in OBPS compliance costs. Opacity exceedances increased significantly during the audit period.

Incremental Cost ($/MW) = ((Marginal Heat Rate \ (Fuel Price + Hg Adder + SO2 Adder + Limestone Adder)) + VOM + OBPS Adder) \ Transmission Loss Factor There are four different types of environmental adders to the Fuel Price that apply depe...

AI summary The incremental cost calculation includes environmental adders such as Hg, SO2, Limestone, and OBPS. NSPI managed SO2 compliance through fuel blending and received a certificate of variance (CoV) in 2025, increasing allowable emissions and removing the SO2 adder from the cost equation for Point Aconi.

emissions at Point Aconi are managed using an adder for the cost of limestone in addition to a PAC adder. It is included in the dispatch equation for Point Aconi for all hours during the audit period. GHG compliance costs under the Output-...

AI summary Emissions at Point Aconi are managed using an adder for limestone costs and a PAC adder in the dispatch equation. The OBPS applies to fossil fuel generation with GHG intensity above a specified level, with adjustments to heat rate curves for some units. These changes affect the dispatch stack, influencing unit operation to manage emissions.

Figure XI-2: Emissions (and other) Adders or Heat Rate Curve Adjustments in Dispatch Equation by Unit, 2024-2025 Unit PAC (Hg+SO2) Limestone (SO2) GHG OBPS Tufts Cove 1 x Tufts Cove 2 x Tufts Cove 3 x Tufts Cove 4 x Tufts Cove 5 x Tufts Co...

AI summary The document outlines emissions adders and heat rate curve adjustments for various units in the 2024-2025 dispatch equation. NSPI manages environmental constraints through fuel choice and blending, particularly for units like Lingan, Trenton, Point Aconi, and Point Tupper, which have no NOx adder in the dispatch equation due to compliance with emissions constraints.

XI.B.8. Management of GHG Emissions through Commitment and Dispatch On January 1, 2023, the Nova Scotia provincial government (Nova Scotia) implemented an outputbased pricing system ("OBPS"), replacing the prior Cap & Trade program. Unlike...

AI summary Nova Scotia implemented an output-based pricing system (OBPS) in 2023, replacing Cap & Trade. OBPS sets performance standards for emissions by fuel type, creating obligations or credits based on actual emissions. Solid fuel generators benefit from higher allowances, but additional costs on solid fuel units have reduced this advantage in the current audit period.

Figure XI-11: CO2eq emissions in tonnes572 Units 2021 2022 2023 2024 2025 Unit 1 Lingan Unit 2 2,637,870 2,110,642 1,541,267 1,643,685 2,100,732 Unit 3 Unit 4 Point Aconi Unit 1 589,431 978,708 876,703 876,083 756,838 Point Tupper Unit 2 7...

AI summary The table shows CO2eq emissions from various units between 2021 and 2025. Emissions from Lingan units increased by 36% from 2023 to 2025, while emissions from Tufts Cove units decreased by 18%. The increase in output and emissions at Lingan, Point Tupper, and Trenton is partially attributed to carbon pricing in the OBPS mechanism.

XI.C. Conclusions Conclusion XI-1: NSPI, to its credit, was able to keep its system running reliably through the period following the cyber event. However, the loss of automation and information required for scheduling and dispatch would h...

AI summary The document highlights NSPI's ability to maintain system reliability post-cyber event but notes inefficiencies and increased costs due to lost automation. It identifies issues with scheduling processes, RTED functionality, and dispatch of PH Biomass. There are concerns about understated system marginal costs and increased GHG emissions. A new Economic Dispatch Optimization Solution is expected to address some inefficiencies.

o longer included 2026 PHP load in its hedging forecast. No hedges were unwound as a result of this decision, nor did we observe any unreasonable hedge positions for 2026 in the third quarter of 2024. Conclusion XIII-12: In the Q2 2025 F&P...

AI summary The document outlines several conclusions regarding NSPI's hedging strategy, emissions compliance, and generation planning. NSPI removed the 2026 PHP load from its forecast, adjusted its expectations for Trenton 5 cold storage, used an SO2 emissions buffer, and found that its hedging program significantly reduced value at risk. NSPI also improved its hedging effectiveness analysis by using slope coefficients and continues to monitor this process.