WIND TURBINE GENERATOR IMPACTS
TO MARINE VESSEL RADAR

Committee on Wind Turbine Generator Impacts to Marine Vessel Radar

Ocean Studies Board

Division on Earth and Life Studies

A Consensus Study Report of

THE NATIONAL ACADEMIES PRESS
Washington, DC
www.nap.edu

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This activity was supported by contracts between the National Academy of Sciences and Bureau of Ocean Energy Management under Award Number 140M0119D0001/140M0121F0013. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.

International Standard Book Number-13: 978-0-309-27548-4
International Standard Book Number-10: 0-309-27548-2
Digital Object Identifier: https://doi.org/10.17226/26430

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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2022. Wind Turbine Generator Impacts to Marine Vessel Radar. Washington, DC: The National Academies Press. https://doi.org/10.17226/26430.

COMMITTEE ON WIND TURBINE GENERATOR IMPACTS TO MARINE VESSEL RADAR

WILLIAM L. MELVIN (Chair), Georgia Institute of Technology, Georgia Tech Research Institute, Smyrna

JENNIFER BERNHARD, University of Illinois at Urbana-Champaign

BENJAMIN KARLSON, Sandia National Laboratories, Albuquerque, New Mexico

HAO LING, The University of Texas at Austin (Ret.)

ANDREW McGOVERN, New Jersey Sandy Hook Pilots Association (Ret.), Great River, New York

JOHN STONE, U.S. Coast Guard, Washington, District of Columbia

Staff

ALEXANDRA SKRIVANEK, Study Director, Ocean Studies Board

EMILY TWIGG, Senior Program Officer, Ocean Studies Board

ELIZABETH COSTA, Program Assistant, Ocean Studies Board

KENZA SIDI-ALI-CHERIF, Senior Program Assistant, Ocean Studies Board (through August 2021)

THANH NGUYEN, Financial Business Partner, Ocean Studies Board

OCEAN STUDIES BOARD

CLAUDIA BENITEZ-NELSON (Chair), University of South Carolina, Columbia

MARK R. ABBOTT, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

CAROL ARNOSTI, University of North Carolina, Chapel Hill

LISA M. CAMPBELL, Duke University, Durham, North Carolina

THOMAS S. CHANCE, ASV Global, LLC (Ret.), Broussard, Louisiana

DANIEL COSTA, University of California, Santa Cruz

JOHN R. DELANEY, University of Washington (Ret.), Seattle

SCOTT GLENN, Rutgers University, New Brunswick, New Jersey

PATRICK HEIMBACH, The University of Texas at Austin

MARCIA ISAKSON, The University of Texas at Austin

LEKELIA JENKINS, Arizona State University, Tempe

NANCY KNOWLTON (NAS), Smithsonian Institution (Ret.), Washington, District of Columbia

ANTHONY MACDONALD, Monmouth University, West Long Branch, New Jersey

THOMAS J. MILLER, University of Maryland, Solomons

S. BRADLEY MORAN, University of Alaska, Fairbanks

RUTH PERRY, Shell Exploration & Production Company, Houston, Texas

JAMES SANCHIRICO, University of California, Davis

MARK J. SPALDING, The Ocean Foundation, Washington, District of Columbia

ROBERT S. WINOKUR, Michigan Tech Research Institute, Silver Spring, Maryland

Staff

SUSAN ROBERTS, Director

STACEE KARRAS, Senior Program Officer

KELLY OSKVIG, Senior Program Officer

EMILY TWIGG, Senior Program Officer

MEGAN MAY, Associate Program Officer (through January 2022)

ALEXANDRA SKRIVANEK, Associate Program Officer

VANESSA CONSTANT, Associate Program Officer

SHELLY-ANN FREELAND, Financial Business Partner (through January 2022)

THANH NGUYEN, Financial Business Partner

BRIDGET McGOVERN, Research Associate

KENZA SIDI-ALI-CHERIF, Senior Program Assistant

ELIZABETH COSTA, Program Assistant

GRACE CALLAHAN, Program Assistant

Preface

Over the past 15 years or so, the impact of wind turbine generator (WTG) interference on radar performance has caught the attention of the U.S. Departments of Defense and Homeland Security, as well as the Federal Aviation Administration, as they strive to ensure the mission effectiveness of their systems. More recently, in January 2021, the Biden Administration issued Executive Order 14008, resulting in a goal of generating 30 gigawatts of offshore wind energy by 2030. The sheer scale of the requisite deployment of WTG farms on the U.S. Outer Continental Shelf (OCS) to meet the objectives for renewable energy holds unique implications for the Maritime Transportation System (MTS), the connection of waterways and ports supporting commerce and recreation.

As marine vessel radars are common tools used by mariners to navigate the MTS, studying the effects of WTGs on radar performance, as well as identifying corresponding mitigating solutions, is an important undertaking for the maritime stakeholder community. The National Academies of Sciences, Engineering, and Medicine convened the Committee on Wind Turbine Generator Impacts to Marine Vessel Radar in 2021 to conduct this study, and this report is a result of that effort.

Marine vessel radars are not presently optimized to operate in a WTG environment. Marine WTGs are very large structures, with towers on the order of several hundred meters and blade lengths exceeding 100 meters. Being heavily composed of steel, the nominal WTG structure has a large radar cross section. Furthermore, many hundreds to thousands of WTGs will be constructed throughout the U.S. OCS. The combination of high radar reflectivity and vast number of WTGs leads to many strong reflected signals entering the radar receiver, further complicated by other factors, such as multipath and range ambiguous returns. In addition, blade motion generates aspect-dependent, Doppler-spread interference. These various effects, left unresolved, combine to complicate navigation decision-making. Certainly, there is a need to collect more data, develop physics-based models, identify key failure mechanisms, and devise mitigating strategies to effectively manage the situation. Such considerations are highlighted in this report, which provides 28 key findings, as well as two specific conclusions and two actionable recommendations to take marine vessel radar into this new era of expansive, offshore, renewable energy.

This report captures the expertise of some of the nation’s leading experts in radar modeling, radar design and applications, marine navigation and safety, and WTG engineering. I want to express my deep appreciation to every member of the committee for their time, talent, and commitment to this important task. I am further grateful for their candor and collegiality, which have served to improve the thought process behind this study while also making for an enjoyable endeavor!

The committee is grateful to the Bureau of Ocean Energy Management for its responsiveness to the many questions and requests for information while developing this report. In particular, we thank Jennifer Draher and Arianna Baker for their guidance throughout the study process. The committee is also grateful to the many individuals who played a role in completing this study. The committee held four major events during the course of the study, and would like to extend its sincere thanks to all those from the federal government, research institutions, private industry, and other stakeholder groups who appeared before the full committee, or provided background information and discussed relevant issues.

Lastly, the committee extends its deepest appreciation to the National Academies’ staff for their invaluable support and many contributions to the project. The successful and timely completion of this effort would not have been possible were it not for the superb efforts of study director Dr. Lexa Skrivanek and program assistant Elizabeth Costa. It has been an honor working with this team, and we are most grateful for their guidance and expertise.

Dr. William Melvin, Chair
Committee on Wind Turbine Generator Impacts to Marine Vessel Radar

Acknowledgments

The committee would especially like to thank the Bureau of Ocean Energy Management (BOEM) staff and contractors for their invaluable assistance in providing background information and responding to information requested by the committee and for their participation in meetings. In particular, the committee thanks Jennifer Draher, Arianna Baker, and Thomas Kilpatrick.

This report was also greatly enhanced by discussions with participants at the committee’s four meetings conducted as part of this study. The committee would like to especially acknowledge the efforts of those who gave presentations at these meetings: Jennifer Draher (BOEM Office of Renewable Energy Programs), Arianna Baker (BOEM Office of Renewable Energy Programs), Eric Kunz (Furuno), David Brigada (Massachusetts Institute of Technology Lincoln Laboratory), Russell Colburn (Booz Allen Hamilton), Jeremiah Sheahen (Maritime Institute of Technology and Graduate Studies [MITAGS]), Robert Becker (MITAGS), Elizabeth Kretovic (Ørsted, North America—Marine Affairs), Ed LeBlanc (Ørsted, North America—Marine Affairs), George Detweiler (U.S. Coast Guard), Bill Haynes (Furuno), Brandon Ennis (Sandia National Laboratories), and Tim Acland (Hensoldt UK [formerly Kelvin Hughes]).

This Consensus Study Report was reviewed as a draft by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

We thank the following individuals for their review of this report:

Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by Clark Gellings (NAE), Clark Gellings and Associates, LLC, and R. Keith Michel (NAE), Webb Institute. They were responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.

Contents

SUMMARY

1 INTRODUCTION

Offshore Wind Energy Development on the U.S. Outer Continental Shelf

Marine Navigation and Radar Interference

Statement of Task

Report Organization

References

2 IMPACTS OF WIND TURBINE GENERATORS ON MARINE VESSEL RADAR

Navigation and Safety Using Marine Vessel Radar

Marine Vessel Radar Design and Operation

Offshore Wind Turbine Generator Characteristics and Deployment

Electromagnetic Characteristics of Wind Turbine Generators

Wind Turbine Generator Impacts on Marine Vessel Radar

References

3 MITIGATING SOLUTIONS FOR WIND TURBINE GENERATOR EFFECTS ON MARINE VESSEL RADAR

Stakeholder Needs and Capabilities

Mitigation Methods

References

4 KEY FINDINGS, CONCLUSIONS, AND RECOMMENDATIONS

Findings

Conclusions

Recommendations

References

APPENDIXES

A COMMITTEE BIOGRAPHIES

B ACRONYM LIST