Offshore Wind Submarine Cabling Overview

1 OverviewOFFSHORE wind Submarine CABLINGF inal Report | Report Number 21-14 | April 2021 Fisheries Technical Working GroupNYSERDA s Promise to New Yorkers: NYSERDA provides resources, expertise, and objective information so New Yorkers can make confident, informed energy Vision:New York is a global climate leader building a healthier future with thriving communities; homes and businesses powered by clean energy; and economic opportunities accessible to all New Mission:Advance clean energy innovation and investments to combat climate change, improving the health, resiliency, and prosperity of New Yorkers and delivering benefits equitably to all.

2 Courtesy, Equinor, Dudgeon Offshore wind FarmPrepared for:New York State Energy Research and Development AuthorityAlbany, NYOffshore wind Submarine Cabling OverviewFisheries Technical Working GroupFinal ReportPrepared by:Tetra Tech, , MAMorgan Brunbauer Offshore wind Marine Fisheries ManagerBrian Dresser Director of Fisheries ProgramsNYSERDA Report 21-14 NYSERDA Contract 111608A April 2021 Offshore wind Submarine Cabling OVERVIEWiiNoticeThis report was prepared by Tetra Tech, Inc. in the course of performing work contracted for and sponsored by the New York State Energy Research and Development Authority (hereafter NYSERDA ).

3 The opinions expressed in this report do not necessarily reflect those of NYSERDA or the State of New York, and reference to any specific product, service, process, or method does not constitute an implied or expressed recommendation or endorsement of it. Further, NYSERDA, the State of New York, and the contractor make no warranties or representations, expressed or implied, as to the fitness for particular purpose or merchantability of any product, apparatus, or service, or the usefulness, completeness, or accuracy of any processes, methods, or other information contained, described, disclosed, or referred to in this report.

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6 It is important that the installation and operation of Submarine cables avoid, minimize, or mitigate potential impacts; both to the environment as well as to existing ocean users. Understanding the fundamentals of Offshore wind Submarine power cable types and construction methods are important in determining the potential impacts cables might have on the commercial fishing industry as well as how commercial fishing practices might impact the cables, once installed. The best and most effective manner to mitigate impacts to fishing interests is engagement with fishermen early in the planning process.

7 Planning tools such as the Cable Burial Risk Assessment (CBRA) determine the recommended depth of lowering (DOL) by taking many factors into consideration, including regional fishing gear activity, type, and penetration depths. Mitigation measures to reduce impacts of fishing to cables may include cable armoring and burial for cable installed on the continental shelf. Reducing the impacts Submarine cables may have on stakeholders and vice versa can be achieved by proper and diligent project planning and , Submarine Cabling activities, fisheries cable interactions.

8 Offshore wind cablesOFFSHORE wind Submarine Cabling OVERVIEWF isheries Technical Working GroupiiiTable of ContentsNOTICE iiABSTRACT iiKEYWORDS iiLIST OF TABLES vLIST OF FIGURES vACRONYMS AND ABBREVIATIONS viiEXECUTIVE SUMMARY ES-11 INTRODUCTION 1 Historical and Existing Submarine Cables in the New York Bight 22 THE Offshore wind INDUSTRY 33 Submarine CABLES IN Offshore wind PROJECTS 5 State and Federal Regulatory Requirements Industry Guidance 5 Cable Route Planning 9 Cable Burial Risk Assessment 10 Geologic Constraints and Concerns 11 Environmental, Fisheries, and Fishing Impacts 11 Cable Types 12 Functions (Export vs.)

9 Array) 15 Array Cable Detail 16 HVAC Export Cable Detail 16 HVDC Export Cable Detail 16 Submarine Cable Installation and Burial 17 Route Clearance and Pre-lay Grapnel Run 17 Cable Installation Export 19 Shore-End Installation 21 Main Lay 22 Offshore Substation Platform 24 Cable Installation Array Cabling 25 First-End Installation 26 Main Lay 27 Second-End Installation 27 Cable Burial 28 Simultaneous Lay and Burial 28 Post-lay Burial 34 Pre-lay Burial 37

10 Cable Burial Tool Summary Table 39 Other Cable Protection Measures 40 Post-lay Cable Surveys 44 Cable Crossings and Techniques 45 Legal and Regulatory Viewpoint 45 Common Cable/Pipeline Crossing Methodologies 45 Offshore wind Submarine Cabling OVERVIEWF isheries Technical Working GroupivTable of Contents Operations and Maintenance 46 Periodic Depth of Burial Surveys 46 Cable Temperature Sensing 46 Cable Vibration Sensing/Distributed Acoustic Sensing 48 Remedial Burial 48 Cable Repair Operations (Array and Export)