Final Report DE-EE0005380: Assessment of Offshore Wind Farm Effects on Sea Surface, Subsurface and Airborne Electronic Systems

Abstract

Executive SummaryBackground: 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. Methodology: A survey of electronic equipment (marine radar, airborne radar, sonar, navigation and communications equipment) that could potentially be impacted by large offshore DE-EE0005380 The University of Texas at Austin vi wind farms was first carried out. The electromagnetics and acoustics teams each developed a systems list (systems listed vs. frequency and applications/s...

High Frequency Radar Wind Turbine Interference Community Working Group Report

“…The adjustment of at least two parameters, the sweep rate and fast-Fourier transform (FFT) length, may simplify efforts to mitigate wind turbine interference in HF radar data (Ling et al 2013;Trockel et al 2018). Oceanographic HF radar systems sweep at slow rates, typically 1-4 Hz, since the target velocities (surface gravity waves and vessels) tend to be slow moving.…”

In-Situ ISAR Imaging of Wind Turbines

“…As a result, the interference of wind farms on radar operations has been a problem of growing concern for the radar community [1]- [4]. The large electrical size of utility-class wind turbines gives rise to significant radar clutter.…”

A Study of Radar Features of Wind Turbines in the Hf Band

“…This has led to many studies documenting the interference due to wind farms on radar detection and tracking capabilities [1][2][3][4][5][6][7][8][9][10][11]. The electromagnetic scattering features of wind turbines in the microwave frequency range have also been studied and reported in detail [12][13][14][15][16][17].…”