Topic:"Transmission Planning" in M11307

KEY FINDINGS Based on the common themes observed, the following are the key guiding principles to inform the Action Plan and Roadmap Items: - Variable renewable capacity additions are required to meet the 2030 targets. Up to 1500MW of addi...

AI summary Key findings emphasize the need for 1500MW additional wind, 200MW solar, and 100-900MW firm capacity by 2030. Battery storage (≥100MW) and the Reliability Tie are critical across scenarios. The Atlantic Loop reduces costs/emissions with government support. Synchronous condensers and SMRs (late 2030s) address system reliability and decarbonization. NS Power updated its 2020 IRP based on 2023 modeling.

Wind & Solar - There is a similar wind buildout for all scenarios between 2025 and 2030. For all scenarios modeled, a significant buildout of approximately 1500MW of new wind capacity (beyond the 600MW in service today) is added to the sys...

AI summary The analysis outlines a planned 1500MW wind and 200MW solar buildout by 2030 across scenarios. The bi-directional Atlantic Loop scenario explores renewable exports/importsWith Hydro Quebec, requiring additional wind capacity. Earlier wind expansion is observed in the No Atlantic Loop reference scenario compared to the With Atlantic Loop scenario.

Integration Assets - The reliability tie[1](#page-7-3) is required in all scenarios to support the integration of variable renewable generation (wind and solar) and to serve as the first leg of the Atlantic Loop (the latter in the with Atl...

AI summary The document discusses the necessity of the Reliability Tie transmission line for integrating variable renewable energy and supporting the Atlantic Loop. It outlines the addition of synchronous condensers by 2030 to support wind integration and references figures illustrating new resource capacity installations by 2030, 2035, and 2050.

ITEM 1: REGIONAL INTEGRATION STRATEGY Develop a Regional Integration Strategy to provide access to firm capacity and low-carbon energy while increasing the reliability of Nova Scotia's interconnection with North America. With virtually no...

AI summary Nova Scotia aims to develop a Regional Integration Strategy to secure firm capacity and low-carbon energy, enhance interconnection reliability with North America, and address the phase-out of coal generation. The strategy emphasizes access to renewable markets and system reliability independent of the Atlantic Loop for wind integration.

Item 1b: Regional Integration Continue working with neighboring jurisdictions in support of the Atlantic Loop and other opportunities for regional integration, conducting detailed engineering and economic studies for firm import options re...

AI summary The text emphasizes collaboration with neighboring jurisdictions for regional integration initiatives like the Atlantic Loop, requiring engineering and economic studies to assess firm import options. Key evaluation criteria include supply security, emission intensity, and dispatch flexibility, alongside necessary transmission investments.

Item 2c: Electrification Impacts – Transmission and Distribution System Address electrification impacts on the Transmission & Distribution system as additional experience and data become available. This will include an analysis of availabl...

AI summary The document outlines plans to analyze electrification impacts on Nova Scotia's transmission and distribution systems, including T&D capacity assessments, mitigation strategies, and cost estimates. It emphasizes leveraging data from NS Power's AMI implementation as it becomes available.

ITEM 10: FIRM IMPORTS Continue to monitor opportunities for near-term firm imports over existing transmission infrastructure.

AI summary The document suggests continuing to monitor opportunities for near-term firm imports using existing transmission infrastructure, indicating a focus on leveraging current systems for energy importation.

an and should be welcome to bid in such an RFP, allowing for a fair and complete comparison of these alternatives to minimize cost and risk to ratepayers while meeting system reliability requirements. Third, to the extent NSPI conducts tec...

AI summary The text emphasizes NSPI's need to use competitive procurement to compare resource alternatives, avoid restrictive RFP quantity targets, and consider market-driven pricing. It highlights IRP scenarios showing how wind and battery cost variations affect project timelines and retirement schedules, advocating for flexible procurement designs like 'price-to-beat' benchmarks. Regional cooperation via external control areas is also recommended to incentivize transmission investments.

C. The Atlantic Loop is a large-scale, interregional megaproject that carries with it potentially unparalleled costs, benefits, and risks In its Final IRP Report issued in late 2020, the Atlantic Loop project was not specifically mentioned...

AI summary The Atlantic Loop project, modeled by NSPI in its IRP, involves transmission lines between New Brunswick and Nova Scotia with potential costs of $1.7 billion. It provides up to 550 MW of firm capacity, relying on ISO New England market price forecasts. The project is central to NSPI's Evergreen Update and IRP Action Plan.

B. Atlantic Loop NS Power confirmed that it has chosen a "No Atlantic Loop" reference scenario (CE1-E1-R2) for planning purposes. (Response to Comments, p. 11) It declined to comment on the likelihood of a contract (or other commitment) fo...

AI summary NS Power has selected a 'No Atlantic Loop' planning scenario, while Bates White highlights financial risks and recommends joint dispatch with New Brunswick. NS Power's valuation methods for bi-directional transactions are criticized as inadequate, with concerns over reliance on uncertain forecasts. The Atlantic Loop's potential benefits and costs are debated, including impacts on system costs and renewable integration.

E. Reliability Tie As we noted in our comments on the modeling results, NS Power has delayed the earliest complefion date of the reliability fie (a second 345 kV AC transmission line from Onslow, NS to Salisbury, NB) unfil at least 2027, r...

AI summary NS Power has delayed the completion of a 345 kV AC transmission line (reliability tie) from Onslow, NS to Salisbury, NB until 2027 due to capital constraints linked to Bill 212. The project, vital for wind integration, is expected to file for review in 2024 with an in-service date of 2028. NS Power and the Board are urged to expedite its review.

that correctly iden�fying the need for capacity is paramount for all subsequent IRP runs. The study should also ask whether energy to meet those peak demands should be stored in a batery, a tank, a lake or in a regionally linked, diversifi...

AI summary The text emphasizes the importance of accurately identifying capacity needs for Integrated Resource Plan (IRP) runs and evaluating energy storage options to meet peak demands. It also raises concerns about NS Power's ability to value bidirectional transactions over future transmission projects and the need to improve forecasting methods.

that correctly iden�fying the need for capacity is paramount for all subsequent IRP runs. The study should also ask whether energy to meet those peak demands should be stored in a batery, a tank, a lake or in a regionally linked, diversifi...

AI summary The text emphasizes the importance of accurately identifying capacity needs for Integrated Resource Plan (IRP) runs and evaluating options for storing energy to meet peak demands. It also raises concerns about NS Power's ability to value bidirectional transactions over future transmission projects, such as the Atlantic Loop, and highlights challenges related to customer behavior and decarbonization policy.

Recommendations Stable and Reliable Integration of Renewables - Verify network response for high Rate of Frequency (RoCoF) system disturbances through EMT simulations. Based on study to date, there are significant concerns for the ability...

AI summary The recommendations focus on ensuring stable integration of renewables by addressing RoCoF risks, upgrading grid interconnection standards, and conducting detailed studies. Concerns include existing RoCoF limits potentially causing cascade tripping, the need for IEEE 1547-2018 alignment, and MHI's proposals for grid study updates. NSPI is urged to review system guidelines and perform incremental studies for each generation/load wave.

System Operator Support to Transition to High IBR Grid - Develop a methodology to estimate the minimum SCMVA and SCR online prior to the addition of additional IBR (WEC, BESS, HVDC etc.) to the NSPI grid. - Develop a methodology to estimat...

AI summary The document outlines the need to develop methodologies for estimating SCMVA, SCR, and inertia online to ensure grid stability before integrating additional IBR (e.g., WEC, BESS, HVDC) into the NSPI grid. It also emphasizes updating operating guidelines and conducting EMT studies to address fault ride-through, control interactions, and system oscillations from expanded IBR interconnections.

[Appendix B: Sensitive SCMVA Buses](#page-58-0) - Table B 1: SCMVA Sensitive Buses, 2023 Typical SCMVA - Table B 2: SCMVA Sensitive Buses, 2023 Minimum SCMVA, 2 thermals, ML - Table B 3: SCMVA Sensitive Buses, 2030 SCMVA, RoCoF Case 511 -...

AI summary Appendix B presents tables analyzing Short Circuit MVA (SCMVA) sensitivity for critical buses in Nova Scotia's power system under various scenarios (2023/2030, thermal limits, tie lines, inertia levels). The data reflects system stability considerations for the Bulk Electric System (BES) under different operational conditions.

[Appendix C: SCR Sensitive Facilities](#page-59-0) - Table C 1: SCR Sensitive Sites, Existing Typical - Table C 2: SCR Sensitive Sites, Existing Minimum Transmission Level Voltage - Table C 3: SCR Sensitive Sites, 2030 RoCoF Case 511 - Tab...

AI summary Appendix C presents tables detailing SCR (Short Circuit Ratio) sensitive facilities under various scenarios, including existing transmission levels, 2030 RoCoF Case 511, and minimum SCMVA conditions. These tables assess system stability risks associated with low SCR values in the Nova Scotia power grid.

o or more dynamic devices in close proximity, leading to unstable or poorly damped oscillations. - Impact from torsional oscillations, sub synchronous Interactions (SSTI), on thermal generator shafts. There has been much study and industry...

AI summary The document discusses challenges in power systems with high renewable penetration, focusing on low short-circuit ratios (SCR) and the need for specialized studies like electromagnetic transient (EMT) simulations. It highlights the importance of system strength, frequency control, and planning practices to manage instability from inverter-based resources and thermal generator interactions.

6.6 Transmission Connections New transmission paths will generally strengthen a power system. The more the ties between areas of a power system the stronger the ability of the system to withstand grid events. For Nova Scotia, additional tr...

AI summary New transmission connections can enhance power system resilience by reducing RoCoF and increasing SCMVA near tie line termini. Two areas in Nova Scotia are identified as having potential to improve grid stability and support IBR resources under various system conditions.

6.6.1 Second Tie with NB The addition of a second 345kV transmission line to New Brunswick would improve System Strength available from New Brunswick in the Onslow area and reduce the impact of the most critical contingency of the present...

AI summary Adding a second 345kV transmission line to New Brunswick would improve system strength in the Onslow area and reduce RoCoF during high imports. However, this may reduce system strength if synchronous units are offline, potentially affecting WEC facilities at lower voltage levels.

6.6.2 Transmission Reinforcement in Western Nova Scotia Traditionally a weak area of the NS grid, the western area of the province may need additional transmission build to support growing load. In the ongoing PSS®E studies, there are volt...

AI summary The western area of Nova Scotia's grid is traditionally weak and may require additional transmission infrastructure to support growing load. PSS®E studies indicate voltage and SCMVA violations for 2030 load and generation dispatch, which could be resolved with new transmission connections, enabling more wind projects in the region.

The Energy Transition Nova Scotia is committed to getting off coal and generating 80 percent of its electricity from renewables by 2030 The Transmission System Transition

AI summary Nova Scotia is committed to phasing out coal and achieving 80% renewable electricity generation by 2030. The document highlights the Transmission System Transition as a key component of this energy transition strategy, though specific technical details are not provided in the text.

Energy and Transmission System Transition - The Energy Transition can be local, in Canada at the provincial level - o Decisions and choices in one province do not have huge impact on a neighbouring utility - o Timelines do not have to be a...

AI summary The document discusses provincial autonomy in energy transitions and challenges in transmission systems due to Inverter Based Resources (IBRs). It highlights that provincial energy decisions have limited cross-border impact but notes IBRs can cause grid instability, oscillations, control interactions, and harmonic distortion.

Transmission System Design and SMEs - Developing good quality EMT simulations models: - o Faster response to grid disturbances - o Higher frequency oscillatory response - o Work with IC, OEM, Simulation and EMT consultants - Existing Plant...

AI summary The document outlines the development of EMT simulation models to enhance grid response, the modeling of existing and new plant technologies, and the importance of accurate load modeling, including non-traditional loads like EVs and hydrogen.

Recommendations - Stable and Reliable Operation - o RoCoF review for existing plant - o TSIR and DSIR revision for high IBR - o Studies for each wave of change, IBR, plant retirements, load growth - Resource Planning, Update IBR and Inerti...

AI summary The document outlines recommendations for ensuring grid stability with high Inverter-Based Resources (IBR), including RoCoF reviews, system strength assessments, inertia constraint updates, real-time operational tools, and black start protocols for dual grids. It emphasizes planning practices for load growth and IBR integration.

Regional collaboration can yield unquantified benefits There are multiple future conditions that have not been modeled by NSPI in this analysis, including a future with significant offshore wind development consistent with the province's M...

AI summary The analysis highlights unmodeled future scenarios, such as offshore wind and hydrogen development, which could benefit from regional collaboration through infrastructure like the Atlantic Loop. NSPI is urged to consider these factors in future planning to assess resource options.

Appendix: ESC Submission on 2023 Evergreen IRP Action Plan & Roadmap Update (M11307) - 1. " In the Nova Scotia context with the expected increase in variable renewable energy resources, expansion of transmission ties, and phase out of coal...

AI summary ESC argues that energy storage will play a critical role in Nova Scotia's energy future due to increasing renewables and coal phase-out. They highlight storage's contributions to firm capacity, peak shaving, and reduced wind curtailment, noting the current IRP underestimates its potential due to modeling limitations.

15 Action Plan Item 1b: Regional Integration 16 This action plan item suggests NS Power will continue to look for opportunities to advance the 17 Atlantic Loop. As suggested elsewhere in this submission, there are several risks present in...

AI summary NS Power plans to advance the Atlantic Loop while considering risks and import opportunities, as advised by Bates White. E1 supports analyzing electrification's impact on transmission and distribution systems, emphasizing the need to account for growing avoided costs in T&D infrastructure due to increased load growth.