THE UNIVERSITY OF TEXAS AT AUSTIN Final Report DE-EE0005380 Assessment of Offshore Wind Farm Effects on Sea Surface, Subsurface and Airborne Electronic Systems Prepared for: U.S. Department of Energy Prepared by: Hao Ling (UT) Mark F. Hamilton (ARL:UT) Rajan Bhalla (SAIC) Walter E. Brown (ARL:UT) Todd A. Hay (ARL:UT) Nicholas J. Whitelonis (UT) Shang-Te Yang (UT) Aale R. Naqvi (UT) 9/30/2013 DE-EE0005380 The University of Texas at Austin Notice and Disclaimer This report is being disseminated by the Department of Energy. As such, the document was prepared in compliance with Section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Public Law 106-554) and information quality guidelines issued by the Department of Energy. Though this report does not constitute “influential” information, as that term is defined in DOE’s information quality guidelines or the Office of Management and Budget's Information Quality Bulletin for Peer Review (Bulletin), the study was reviewed both internally and externally prior to publication. For purposes of external review, the study benefited from the advice, technical responses and comments of an expert group of stakeholders. That group of contributors and reviewers included representatives from academia, private corporations, national laboratories, and a broad spectrum of federal agencies. ii DE-EE0005380 The University of Texas at Austin Acknowledgments For their support of this report, the authors thank the entire U.S. Department of Energy (DOE) Wind & Water Power Technologies Program team, and in particular Brian Connor, Gary Norton, Bryan Miller, Michael Hahn, Gretchen Andrus, and Patrick Gilman. For providing key input and reviewing elements of this report, we also acknowledge: George Detweiler, USCG; Daniel Freedman, USCG; Tim Crum, NOAA; Ed Ciardi, NOAA; Jack Harlan, NOAA; Pete Lessing, NOAA; Nick Shay, University of Miami; Edward Davison, NTIA; Tracy Cassidy, DHS; John Yarman, Air Force; Dave Belote, DOD; Frederick Engle, DOD; John Zentner, NORAD; Lynne Neuman, AFSPC; Walter Schobel, AFSPC; Dwight Deakin, NAVAIR; John Page, FAA; Douglas Klauck, FAA; Don Bui, FAA; Jeff Bogen, FAA; Rajiv Gautam, FAA; Stephen O'Malley, Fishermen’s Energy; Clark Speicher, Lockheed Martin; Kurt Olsen, Lockheed Martin; Charles Liang, Lockheed Martin; Klaus-Werner Gurgel, University of Hamburg; Lucy Wyatt, James Cook University; Donald Barrick, CODAR Ocean Sensor; Calvin Teague, CODAR Ocean Sensor; Kathleen O’Neil, NOAA;Peter Hughes, Fishermen’s Energy; Fred Pease, DOI; Brian Kent, Air Force; John Stubstad, DOD; Nick Ferratella, Navy; Wesley Bomyea, Navy; George Ioup, University of New Orleans; Juliette Ioup, University of New Orleans; Grayson Rayborn, University of Southern Mississippi; Shawn Rice, ION GeoVentures; Dale Lambert, ION GeoVentures; Craig Beasley, Schlumberger; Clifford Frohlich, University of Texas at Austin; Raymond Soukup, ONR; George Thomas, USCG; Rodney Nelson, Schlumberger; Melissa Sanderson, Cape Cod Commercial Hook Fisherman's Association; Joseph Rice, Naval Postgraduate School; Kenneth Krueger, ARL:UT; Christopher Tiemann, ARL:UT; Nicholas Chotiros, ARL:UT; Rick Bailey, ARL:UT; Gary Wilson, ARL:UT; Megan Ballard, ARL:UT; Frank Stone, Navy; James Miller, University of Rhode Island; Gopu Potty, University of Rhode Island; Megan McCluer, Air Force; Jose Zayas, DOE; Joel Cline, DOE; Russell Wright, DHS; Joel Wall, DHS; Donald Fraser, DHS; James Baird, FAA; E. J. Beaulieu, FAA; Mark Carmouche, FAA; Mike Hensley, FAA; Michael Aimone, DOD; William Van Houten, DOD; Louis Husser, DOD; Paul Karch, DOD; Kimberly Stroud, DOD; Mark Bishop, NORRAD; Shawn Jordan, Air Force; Franz Busse, MIT Lincoln Lab; Richard Younger, MIT Lincoln Lab; Christopher Keck, MIT Lincoln Lab; Jason Biddle, MIT Lincoln Lab; Howard Swancy; David Minster, Sandia National Labs; Milford Estill, Sandia National Labs; Benjamin Karlson, Sandia National Labs; Bruce LeBlanc, Sandia National Labs; Leroy Garley, Sandia National Labs; Lenore Boulton, Sandia National Labs. iii DE-EE0005380 The University of Texas at Austin Table of Contents - Executive Summary . v - Introduction . 1 - Section 1. Survey of Electronic Systems and Literature on Wind Farm Interference . 2 - Section 2. Engagement with Key Stakeholders . 11 - Section 3. Assessment Based on First-Principle Modeling . 17 - Section 4. Conclusions and Recommendations . 28 - Section 5. References . 31 - Appendix A. Details on Survey of Electronic Systems . 44 - Appendix B. Details on Stakeholder Interviews . 53 - Appendix C. Details on First-Principle Modeling . 89 - Appendix D. Approval for Public Release Documents . 164 iv DE-EE0005380 The University of Texas at Austin Executive Summary Background: Offshore wind energy is a valuable resource that can provide a significant boost to the US renewable energy portfolio. A current constraint to the development of offshore wind farms is the potential for interference to be caused by large wind farms on existing electronic and acoustical equipment for surveillance, navigation and communications. Therefore, the U.S. Department of Energy funded this study as an objective assessment of possible interference to various types of equipment operating in the marine environment where offshore wind farms could be installed. The interference due to land-based wind farms on radar under certain circumstances has already been widely publicized and studied. The rotation of the turbine blades can give rise to strong Doppler clutter, which can interfere with the operation of existing military, aviation and weather radar systems. In Europe, investigations on the effect of offshore wind farms on marine navigation have been conducted as early as 2004. To date, no comprehensive study of the potential for electromagnetic interference has yet taken place in the US for offshore wind farms. This is due in large part to the lack of any operating offshore wind farms in the US. For acoustics, while there have been many studies of whether airborne noise generated by wind turbines impacts communities, none was found describing how the sound radiated underwater by offshore installations impacts acoustical equipment. Except in relatively close proximity to the wind farms, a distance that depends on many factors including environmental and those specific to the wind farm itself, the radiated sound pressure levels are comparable to ambient noise levels in coastal waters. Objective: The objective of this project was to conduct a baseline evaluation of electromagnetic and acoustical challenges to sea surface, subsurface and airborne electronic systems presented by offshore wind farms. To accomplish that goal, the following tasks were carried out: i. Survey electronic systems that can potentially be impacted by large offshore wind farms, and identify impact assessment studies and research and development activities both within and outside the US, ii. Engage key stakeholders to identify their possible concerns and operating requirements, iii. Conduct first-principle simulations on the interactions of electromagnetic signals with, and the radiation of underwater acoustic signals from, offshore wind farms to evaluate the effect of such interactions on electronic systems, and iv. Provide impact assessments, recommend mitigation methods, prioritize future research directions, and disseminate project findings. This report was produced on behalf of the Wind and Water Power Technologies Program within Department of Energy’s (DOE’s) Office of Energy Efficiency and Renewable Energy (EERE), under grant number DE-EE0005380. The award resulted from Funding Opportunity Announcement DE-FOA-0000414, entitled U.S. Offshore Wind: Removing Market Barriers, Topic Area 7: Impact on Electronic Equipment in the Marine Environment. Methodology: A survey of electronic equipment (marine radar, airborne radar, sonar, navigation and communications equipment) that could potentially be impacted by large offshore v DE-EE0005380 The University of Texas at Austin wind farms was first carried out. The electromagnetics and acoustics teams each developed a systems list (systems listed vs. frequency and applications/stakeholders). In addition, a review of both US and non-US literature related to wind farm interference on electromagnetic and acoustic systems was conducted. For electromagnetic systems, the literature was grouped into marine navigation, air traffic control, weather and ocean monitoring, air defense and long-range surveillance, communications systems, and mitigation techniques. For underwater acoustic systems, the literature was grouped into noise measurements, impact on marine mammals, impact on fish/fisheries, and mitigation techniques. Next, the project team engaged several key stakeholders in government and industry to identify concerns on interference from offshore wind farms, characterize potential impact to operations, determine known requirements and options for mitigation, and establish research needs. In- depth personal interview was chosen as the appropriate research approach to gather technical information and opinions on the subject matter from a wide range of stakeholders in both electromagnetics and underwater acoustics. Interviews were carried out to understand past experiences with land-based wind farm interference and potential concerns with future offshore wind farms on various systems operated by the stakeholders. Through this process, key technical issues were identified and addressed in the subsequent modeling study. The electromagnetic