The Tufts University Power Systems and Markets research group

provides public information on the global transition to renewables.

This information supports decision making in the long-term

interest of society. In recognition of the Massachusetts Department

of Energy Resources (DOER) 2020 requests for information

regarding Offshore Wind Transmission, this report focuses on the

Massachusetts and Rhode Island Wind Energy Areas and their role

in ISO New England’s transition to renewables.

2020 DOER Timeline

January 15: Request for Round 1 Comments

February 18: Responses Submitted

March 3: Technical Conference

March 19: Request for Round 2 Comments

April 21: Round 2 Comments Due

May 12: Tufts Final Report Complete

Major Themes:

1. Long-Term Health of OWE Industry

2. Grid Reliability, Resilience, and Redundancy

3. Environmental Impacts

4. Social Impacts to Coastal Communities

Impacts toEnvironment

Impacts toCoastal Communities

Ocean

Land

Focus Area

Proposed Generation by Type in ISO-NE Queue.

Offshore Wind Transmission in New England

12729MW

13250MW

14800MW

20573MW

20927MW

2016 2017 2018 2019 2020

Offshore Wind Procurements

Proposed Offshore Wind

Proposed Land-Based Wind

Other Proposed Generation

464

3779

8486

2054

3795

7401

8004063

4489

6248

1600

9500

3955

7118

1600

13500

756

6671

Vineyard Wind I Procured Mayflower Wind I Procured

Scenario Comparison:

• Scenario 1 causes more seafloor disturbance in critical resource areas than Scenario 2

• Scenario 2 requires more intense regional coordination and larger up-front investment than Scenario 1

• Scenario 2 requires added expense from HVDC inverter stations (depicted as square grey nodes where offshore cables converge)

• Scenario 2 may have grid balancing benefits not realized in Scenario 1. Further analysis is forthcoming in a whitepaper entitled, Networked Transmission vs. Generator Lead Lines: A Comparative Study of Offshore Transmission Approaches for the Massachusetts and Rhode Island Wind Energy Areas, which the Tufts research group plans to publish in May.

Key Assumptions:

• Policy and technical limitations are drawn from information available in March 2020

• DC transmission is used for export cable length longer than 80 mi unless developers specify otherwise.

• Turbines are situated in a 1 nautical mile grid

• Each black node in Scenario 2 represents a location where one or more 1,200 MW HVDC substations can be sited to service multiple transmission lines

• Each turbine has a capacity of 12 MW, unless otherwise noted

• Each block is approx. 800 MW, unless otherwise noted (or wind energy area cannot be divided into even 800 MW projects)

Scenario 1: Generator Lead Lines

Developer Project Name Project Capacity (MW)

Turbine Capacity (MW)

Substation # of Cables

Voltage (kV)

Type

Orsted/Eversource South Fork Wind 120 8 Buell Lane (East Hampton, NY)

1 138 AC

Orsted/Eversource Revolution Wind 704 8 Davisville (North Kingston, RI)

TBD TBD AC

Orsted/Eversource Sunrise Wind 880 8 Holbrook (Ronkonkoma, NY)

TBD TBD AC

Vineyard Wind Vineyard Wind 1 798 9.5 Barnstable Switching Station (Barnstable, MA)

2 220 AC

Vineyard Wind Park City Wind 804 12(assumed)

West Barnstable Substation (Barnstable, MA)

TBD TBD AC

Mayflower Wind Mayflower Wind 1 804 12(assumed)

Bourne Switching Station (Bourne, MA)

TBD TBD AC3

Existing ProjectsScenario 2 depicts existing projects with HVAC transmission as specified by the developers. Due to current limits on technology, an 800 MW project requires two 400 MW AC cables. Hence, AC transmission is represented by two parallel lines.

Scenario 2: Independent Transmission Network

Contributors:

Samuel Lenney is a master’s student studying electrical engineering at Tufts University. He focuses on trends in developing technologies related to offshore wind transmission and the challenges and opportunities they bring.

Oliver Marsden is an electrical engineering senior. He specializes in technical knowledge, public speaking experience, and financial proficiency for budding interdisciplinary fields within renewable technology.

Sean Murphy is a civil engineering senior. He specializes in water, transportation, and energy systems. Sean has worked on energy from government, utility, and academic perspectives.

Kelly Smith is a master’s student studying offshore wind energy engineering at Tufts University. Kelly is a licensed Professional Engineer in Massachusetts as well as a Certified Floodplain Manager and Envision Sustainability Professional. She currently serves on the board of New England Women in Energy and the Environment.

Chisaki Watanabe is a master’s student at the Fletcher School. Her research focuses on climate change diplomacy and energy security. She was an energy reporter for Bloomberg News in Tokyo and covered power markets and renewable energy in Japan and other Asian countries.

Eric Hines, Ph.D., P.E., F. SEI directs the offshore wind energy graduate program at Tufts University, where he is the Kentaro Tsutsumi Professor of the Practice in structural engineering. Dr. Hines has over 20 years of experience designing innovative infrastructure and large-scale structural tests.

Barbara Kates-Garnick, Ph.D. is a professor of practice at the Fletcher School. She recently served as Undersecretary of Energy for the Commonwealth of Massachusetts (EEA). Her prior work in public service includes Commissioner of Public Utilities (MA DPU)., Assistant Secretary of Consumer Affairs, and Director of Rates and Research (MA DPU).

Aleksandar Stankovic, Ph.D., F.IEEE, is the Alvin H. Howell Professor of Electrical Engineering. Dr. Stankovic has over 30 years of experience in power systems engineering and control.

Sources:

• Anbaric. (2019). Press Release: Anbaric Files with BOEM to Develop Independent Ocean Grid for Southern New England. Wakefield, MA.

• ESS Group. (2014, September). Offshore Wind Transmission Study Final Report. https://files.masscec.com/research/MassCECOSWTransmissionStudy.pdf

• ISO New England, Inc. (2018). ISO New England System Diagram.

• ISO New England, Inc. 2016-2020 Regional Electricity Outlook. https://www.iso-ne.com/about/regional-electricity-outlook/

• Land Transmission Data: The Homeland Infrastructure Foundation-Level Data (HIFLD) Substation Update 10/7/2019; Line Update 9/24/2019

POWER-USMASSACHUSETTS