Attachment 1 Project Narrative www.essgroup.com TABLE OF CONTENTS SECTION PAGE 1.0 INTRODUCTION ..................................................................................................................................... 1 1.1 Purpose and Need ............................................................................................................................ 1 2.0 DETAILED PROJECT DESCRIPTION ................................................................................................... 2 2.1 Description and Location of Proposed West Point Project ............................................................... 2 2.1.1 Northern Interconnection ........................................................................................................ 3 2.1.2 Northern AC Cable Route ....................................................................................................... 3 2.1.3 Northern Converter Station ..................................................................................................... 4 2.1.4 Northern Land Cable Route .................................................................................................... 4 2.1.5 In-River Cable Route .............................................................................................................. 4 2.1.6 Southern Land Route .............................................................................................................. 8 2.1.7 Southern Converter Station .................................................................................................... 8 2.1.8 Southern AC Cable ................................................................................................................. 8 2.1.9 Southern Interconnection ........................................................................................................ 9 2.2 In-River Cable Coexistence with Champlain-Hudson Power Express ............................................. 9 2.2.1 West Point Project In-River Cable Installed Prior to CHPE Project Cable (Alternative 1A) ... 9 2.2.2 CHPE Project Cable Installed Prior to West Point Project In-River Cable (Alternative 1B) . 10 2.3 Description of Proposed Transmission Line ................................................................................... 11 2.3.1 Project Components ............................................................................................................. 12 2.3.2 320 kV DC Circuit .................................................................................................................. 12 2.3.2.1 In-River Cable .............................................................................................................. 12 2.3.2.2 HVDC Land Cable ....................................................................................................... 13 2.3.3 AC Land Cable ...................................................................................................................... 13 2.3.4 Fiber Optic Communications Cable ...................................................................................... 14 2.4 Description of Converter Stations ................................................................................................... 14 2.4.1 VSC-HVDC Converter Stations ............................................................................................ 14 2.4.2 Control and Protection .......................................................................................................... 16 2.4.3 Cooling Systems ................................................................................................................... 16 2.4.4 Fire Protection ....................................................................................................................... 16 2.5 Installation Methods and Means ..................................................................................................... 16 2.5.1 Anticipated Project Schedule ................................................................................................ 16 2.5.2 Cable System Installation ..................................................................................................... 17 2.5.2.1 Land Cables ................................................................................................................ 17 2.5.2.2 Landfall Transitions ..................................................................................................... 18 2.5.2.3 Horizontal Directional Drilling ...................................................................................... 19 2.5.2.4 In-River Cable .............................................................................................................. 22 2.5.3 Cable System Reliability ....................................................................................................... 24 2.5.4 Cable System Maintenance .................................................................................................. 24 2.5.5 Converter Station Construction ............................................................................................. 25 2.6 In-River Cable Burial Depth ............................................................................................................ 26 3.0 ALTERNATIVES ANALYSIS ................................................................................................................ 27 3.1 Purpose and Need .......................................................................................................................... 27 3.2 No Action Alternative ...................................................................................................................... 27 3.3 Selection of Interconnecting Substations ....................................................................................... 28 3.3.1 Criteria for Selection of Interconnecting Substations ............................................................ 28 3.3.2 Northern Interconnection Substation Alternatives ................................................................ 28 3.3.2.1 National Grid Leeds Substation ................................................................................... 28 3.3.2.2 Alternative Northern Interconnection Substations ....................................................... 28 3.3.3 Southern Interconnection Substation Alternatives ................................................................ 29 3.3.3.1 Buchanan Substation .................................................................................................. 29 3.3.3.2 Alternative Southern Interconnection Substations ...................................................... 29 3.3.4 Comparisons and Selection of Interconnection Substations ................................................ 29 © 2013 ESS Group, Inc. k:\w296-000 west point partners route concept\regulatory\usace\attachment 1_project narrative\attachment 1_proj. narrative.doc TABLE OF CONTENTS (CONTINUED) SECTION PAGE 3.4 Selection of Project Converter Station Locations ........................................................................... 29 3.4.1 Criteria for Selection of Converter Station Locations ............................................................ 29 3.4.2 Northern Converter Station ................................................................................................... 30 3.4.3 Southern Converter Station .................................................................................................. 31 3.4.4 Comparisons and Selection of Converter Station Locations ................................................ 31 3.5 Selection of Transmission Line Routes and Landfalls – Overview ................................................ 31 3.5.1 Overhead versus Buried ....................................................................................................... 31 3.5.2 Underground versus Underwater .......................................................................................... 32 3.5.3 Route and Landfall Alternatives ............................................................................................ 33 3.6 Selection of Transmission Line Routes .......................................................................................... 33 3.6.1 Criteria for Selection of Routes ............................................................................................. 33 3.6.2 Summary of Proposed Route (Preferred Alternative – R1) .................................................. 34 3.6.3 In-River Alternatives Evaluated ............................................................................................. 34 3.6.3.1 In-River Cable Coexistence with CHPE ...................................................................... 35 3.6.3.2 Alternative R2 .............................................................................................................. 35 3.6.3.3 Alternative R3A ............................................................................................................ 36 3.6.3.4 Alternative R3B ............................................................................................................ 36 3.6.3.5 Alternative R4 .............................................................................................................. 37 3.6.3.6 Alternative R5 .............................................................................................................. 38 3.6.3.7 Alternative R6 .............................................................................................................