Topic:"Infrastructure Planning" in M12799

JUSTIFICATION: Justification Criteria: Distribution System Sub Criteria: Requirement to Serve

AI summary The document outlines the 'Justification Criteria' under the 'Distribution System' category, focusing on the 'Requirement to Serve' sub-criteria. This section likely addresses regulatory obligations related to service delivery and compliance within the distribution network.

Why do this project ? The existing submarine power cable was installed in 1977, and is the only source of power for customers on Big Island. The cable has reached the end of its design life and an unplanned failure of the cable, and the su...

AI summary The existing 1977 submarine power cable serving Big Island has reached the end of its design life, posing a risk of extended outages if it fails. Installing a new cable while the existing one remains operational will enhance service reliability and availability for customers.

Why do this project now? The Big Island submarine cable has now reached a point where replacement is required to maintain reliable service. The original 1977 cable experienced a fault and was replaced in the late 1990s; however, the 1999-v...

AI summary The Big Island submarine cable, originally installed in 1977 and later replaced in 1999, has failed again, leaving no redundancy. NS Power is reusing the original 1977 cable, which exceeds its 40-year lifespan and poses reliability risks. Immediate replacement is necessary to avoid outages from potential failures, with project completion tied to overhead distribution upgrades by June 2027 and a Final Cost Date of June 2028.

Why do this project this way? A subsea replacement was selected after evaluating and ruling out two land-based alternatives—an overhead line along the Big Island causeway and a trenched underground cable in the same corridor. While an over...

AI summary A subsea cable replacement was chosen over land-based alternatives due to higher failure risks from open-water exposure and climate-driven storm severity on the Big Island causeway. The subsea solution offers lower lifecycle risk, greater reliability, and reduced environmental exposure.

Title: 539N-201 Big Island Subsea Cable Replacement Description Unit Quantity Un it Estimate To tal Estimate Cost Support Reference Completed Simi Projects (FP#'s Regular I abour Engineering PD 318 $ 452 143,881 Sub-Total $ 143,881 Mater i...

AI summary The document outlines the cost estimates for the Big Island Subsea Cable Replacement project, detailing various components such as engineering, materials, and installation costs. The table provides a breakdown of costs for different phases of the project, including cable installation, surveying, and site supervision.

CI C0080101 – 539N-210 Big Island Subsea Cable Replacement (NSEB M12799) NSPI Responses to NSEB Information Requests 1 Request IR-1: 11 12 (d) Please provide the relevant cable engineering design, load study and system planning 13 reports....

AI summary NSPI is responding to NSEB information requests regarding the Big Island Subsea Cable Replacement project. The response includes details on the proposed AC cable, its compliance with technical specifications, and the planned marine survey to finalize the cable route.

• ANSI/NEMA WC 74/ICEA S-93-639 5-46 kV Shielded Power Cable for Use in the Transmission and Distribution of Electric Energy • ICEA S-94-649 Standard for Concentric Neutral Cables Rated 5 through 46 kV • AEIC Standard CS8 Specification for...

AI summary The document outlines technical standards for power cables and discusses NS Power's plan to retain existing subsea cables as a redundancy. It also mentions the preparation for permit applications and the potential use of a diesel generator as an interim power supply option in the event of cable failure.

NON-CONFIDENTIAL 1 2 (b) Installation plans and associated supporting studies will be developed following 3 completion of the final submarine cable route design and in consultation with the selected 4 installation contractor. 5 6 The insta...

AI summary The text outlines the installation process for a submarine cable, including planning, execution, and testing. It mentions the use of industry best practices, the involvement of a selected contractor, and the use of a VLF test to ensure safety. A Request for Information (RFI) has been conducted to identify potential cable manufacturers, but no formal procurement has been initiated.

8 Information (RFI) has been completed, and potential suppliers have been identified. 9 The survey is anticipated to be completed in Q3 2026. 10 11 • Subsea Cable Installation and Protection including Landfall Civil Works 12 13 NS Power is...

AI summary Nova Scotia Power Inc. (NSPI) has initiated a Request for Information (RFI) process to pre-qualify vendors for subsea cable installation and protection, with the agreement expected to be finalized in Q4 2026. The project is contingent on approvals from DFO and DNRR, and cable manufacturing schedules.

2 (e) A subsea cable installed in a sheltered harbour presents lower lifecycle risk and higher 3 reliability than land-based alternatives by avoiding the exposed causeway environment. 4 Overhead lines are subject to wind, ice, and storm su...

AI summary The text compares the reliability and risk of subsea cables installed in sheltered harbors to land-based alternatives, noting that subsea cables face lower lifecycle risks due to isolation from surface storm forces, while overhead lines and trenched underground cables are more vulnerable to environmental factors.

NON-CONFIDENTIAL - 1 Civil upgrades on island landing site : The civil scope referenced pertains to the Brownsville - 2 landing. The associated cost estimate is based on pricing provided by a local civil contractor and - 3 is subject to re...

AI summary The document references civil upgrades at the Brownsville landing site, with a cost estimate based on a local contractor's pricing. The estimate is subject to refinement based on final design and execution requirements. Filed on May 11, 2026, as part of NSPI's regulatory proceeding (NSEB IR-16 Page 4 of 4).

Note 2: Small differences in totals are attributable to rounding. 1 Request IR-18: 27 28 (ii) Please explain why the subsea cable option received a rating of "High" for this 29 criterion, whereas the Underground Cable Causeway option recei...

AI summary The text requests NS Power to explain the rating differences between the subsea cable and underground cable options for maintenance and repair, including their standard practices, condition assessments, and repairability of the proposed subsea cable compared to older cables.

1 2 (iv) Yes. As part of the project, NS Power plans to procure additional spare cable and 3 associated accessories to support timely response in the event of a cable failure and 4 to improve repair lead times. Furthermore, the new cable i...

AI summary NS Power plans to procure additional spare cable and accessories to improve response times and repair lead times in the event of a cable failure. The new cable installation will follow established risk mitigation practices, including appropriate routing and burial depth. Faulty cables are isolated, tested, and repaired using approved methods, followed by integrity testing.

M12799 – Nova Scotia Power Inc. – CI C0080101 – 539N-201 Big Island Subsea Cable Replacement – $4,388,679 On April 9, 2026, Nova Scotia Power Inc. (NS Power) filed a request with the Nova Scotia Energy Board (Board) for approval of a 2026...

AI summary Nova Scotia Power Inc. (NS Power) requested approval for the replacement of the Big Island Subsea Cable, with an increased project cost of $4,388,679 due to additional engineering requirements. The existing cable, installed in 1977, has exceeded its service life and poses a risk of extended outages. The Nova Scotia Energy Board issued information requests, to which NS Power responded, explaining the project's necessity and details.

Request IR-2: - a. Please explain whether the new subsea cable(s) is an AC or DC cable. - b. Please identify the number of cable(s) to be installed and provide the related technical specifications, including but not limited to voltage rati...

AI summary Request IR-2 seeks detailed information about proposed subsea cables, including technical specifications, compliance with standards, contingency plans for service disruptions, and required permits. Questions focus on cable type (AC/DC), routing maps, engineering reports, environmental regulations, and restoration strategies for Big Island.

Request IR-3: - a. Please explain whether the proposed project budget includes any related onshore and near-shore land works and any associated equipment that may be required. - i. If not, please explain. - ii. If yes, please identify and...

AI summary Request IR-3 seeks clarification on project budget details, including onshore/near-shore land works and equipment, subsea cable installation methods, testing/commissioning plans, and warranty terms for new subsea cables.

Request IR-5: - a. Please describe the cause(s) of the fault on the subsea cable installed in 1977 and the rationale for the decision to replace it with the subsea cable installed in the 1990s. - b. Please explain how NS Power determined t...

AI summary Request IR-5 seeks explanations regarding the 1977 subsea cable's faults, the rationale for replacing it with a 1990s cable, NS Power's assessment of the 1977 cable post-1990s failure, and any subsequent faults since 1999. It also questions why a prior condition assessment of the 1977 cable was not conducted before installing the 1990s cable.

Request IR-8: - a. Please provide a table that lists the past five years of load records for Big Island, including but not limited to peak and average demand, as well as the load forecast over the expected service life of the proposed new...

AI summary Request IR-8 seeks data on Big Island's load records over the past five years and forecasts for new cable infrastructure, alongside a comparison of new subsea cables with older ones from 1977 and the 1990s, focusing on design, performance, and maintenance.

Request IR-9: - a. Please describe the plan for the existing cables after the completion of the new cable installation. - i. If the plan is to remove, abandon or decommission the existing cables, please confirm whether the quoted budget in...

AI summary Request IR-9 seeks clarification on the fate of existing cables post-new installation, including removal/decommissioning plans, budget inclusion, rationale for retention, and whether the 1977 cable will remain for redundancy.

Request IR-10: In "Why do this project this way", NS Power noted that: A subsea replacement was selected after evaluating and ruling out two land-based alternatives—an overhead line along the Big Island causeway and a trenched underground...

AI summary NS Power is asked to justify selecting a subsea cable over land-based alternatives (overhead line and trenched underground) due to high failure risks from climate factors. Requests include technical analysis, economic models, and comparisons of risks and reliability between options.

Request IR-11: - In the "Reason for Variance", NS Power noted that the increase of $849,612 from the 2026 ACE - Plan is to account for the following tasks: - … the increased estimate covers the inclusion of a marine geo-technical survey re...

AI summary NS Power explains an increase in the 2026 ACE Plan due to additional tasks for a subsea cable project, including marine surveys and landfall execution. Questions are raised about the commonality of these tasks and their absence in the original proposal.

Request IR-12: - a. For the listed consulting works in the Capital Project Detailed Estimate, please provide all relevant studies and technical reports prepared for the project, including cable engineering design and routing, metocean data...

AI summary Request IR-12 seeks technical reports, consultant scopes, and concerns related to a capital project's detailed estimate, including environmental and technical studies such as cable design, metocean data, and habitat assessments.

Request IR-17: - a) Please provide a comprehensive cost estimate for the trenched underground land cable option and a copy of NS Power's Economic Analysis Model (EAM) comparing it with the subsea cable option. Any costs incurred to date th...

AI summary Request IR-17 seeks cost estimates, route details, and technical comparisons for trenched underground vs. subsea cable options. IR-18 questions reliability ratings and maintenance practices for subsea and underground cables, noting discrepancies in outage risks and repairability. The subsea cable is rated 'High' for reliability, while the underground option is 'Moderate' due to potential excavation challenges.

M12799 – Nova Scotia Power Inc. – CI C0080101 – 539N-201 Big Island Subsea Cable Replacement – $4,388,679 On April 9, 2026, Nova Scotia Power Inc. (NS Power) filed a request with the Nova Scotia Energy Board (Board) for approval of a 2026...

AI summary Nova Scotia Power Inc. (NS Power) filed a request for approval of a subsea cable replacement project, citing the age and condition of the existing cable installed in 1977. The project's estimated cost has increased due to additional engineering requirements, and the Board has issued multiple Information Requests to NS Power for clarification.