Deployment Of Wave Energy Converters Research Articles

An integrated approach for the decision of wave energy converter deployment based on forty-five-years high-resolution wave climate modeling

Climate change is driving the urgent need for sustainable and renewable energy sources to mitigate its impacts and reduce greenhouse gas emissions. Ocean wave energy, as one of the promising alternatives to fossil fuels, plays a critical role in providing renewable energy in coastal areas. To fully exploit regional wave energy potential, various performance metrics of wave energy converters (WECs) need to be considered to optimize location decisions and WEC categories. This study introduces an integrated approach by incorporating a novel factor, the maximum consecutive cut-off duration of WECs due to extreme weather conditions. It aims to enhance the efficiency of WEC selection and deployment location optimization in the southern and eastern Asian seas. Through 45 years of high-resolution (up to 250 m) ocean wave simulations, conducted using WaveWatch III ®(WW3) on unstructured mesh, Wave Dragon was identified as providing the highest index. This study suggests that placing WECs along the coastlines of the South China Sea, the eastern and northern Bay of Bengal, the western sector of the Malay Archipelago, and parts of the Arafura Sea may result in the most efficient conversion of wave energy in the southern and eastern Asian seas. While the proposed approach alone may not dictate deployment decisions, this study provides an applicable index to potentially rank WEC deployment options in the eastern and southern Asian seas, by considering both exploitable wave energy production, and long-term stability.

Economic feasibility study for wave energy conversion device deployment in Faroese waters

As the world continues to battle with increasing energy demand along with the serious effects of climate change, there is a need for more reliable renewable energy sources. The objective of the present work is to study the economic feasibility for deployment of wave energy conversion devices in the Faroese coastal region. We analyze eight different wave energy conversion concepts under development at nine different nearshore locations in the Faroese coastal region. The nine different locations are classified into three coastal locations — three on the west coast, three on the east coast and three on the north coast. The eight wave energy conversion devices mostly rely on different working principles, though some of these are similar. Results show that there is quite a significant difference in the performance of the devices from coast to coast. There is also a difference between the different conversion devices as they rely on different principles and the suitability of each device varies from location to location. We also show that the Faroe Islands are a suitable location for wave energy converter deployment compared to other places. Furthermore, results show that the performance of wave energy converters in the Faroe Islands can prove to be a direct competitor to offshore floating wind energy.

Cost-Effective Optimization of an Array of Wave Energy Converters in Front of a Vertical Seawall

The present paper focuses on investigating the cost-effective configuration of an array of wave energy converters (WECs) composed of vertical cylinders situated in front of a vertical seawall in irregular waves. First, the hydrodynamic calculations are performed using a WAMIT commercial code based on linear potential theory, where the influence of the vertical wall is incorporated using the method of image. The viscous damping experienced by the oscillating cylinder is considered through CFD simulations of a free decay test. A variety of parameters, including WEC diameter, number of WECs, and the spacing between them, are considered to determine an economically efficient WEC configuration. The design of the WEC configuration is aided by a cost indicator, defined as the ratio of the total submerged volume of the WEC to overall power capture. The cost-effective configuration of WECs is achieved when WECs are positioned in front of a vertical wall and the distance between them is kept short. It can be explained that the trapped waves formed between adjacent WECs as well as the standing waves in front of a seawall significantly intensify wave fields around WECs and consequently amplify the heave motion of each WEC. A cost-effective design strategy of WEC deployment enhances the wave energy greatly and, consequently, contributes to constructing the wave energy farm.

Identification of optimal sites for the deployment of wave energy converters: the importance of a technology-centred approach

Driven by climate issues and geopolitical uncertainties, Europe faces the need to transform its energy supply dramatically and quickly. Various renewable technologies are proposed as a medium- to long-term solution for an environmentally and economically sustainable energy mix: among the available solutions, wave energy converters (WECs) are attracting growing interest due to the large untapped wave energy potential in European seas. In this context, the choice of optimal locations for the use of wave energy is fundamental to limit the technological gap with other fully developed conversion technologies, and to ensure competitive energy costs. In this paper, we compare different possible strategies to identify suitable sites for the installation of WECs, namely the one based on pure analysis of the wave energy resource, and that considering the productivity of the device in different sea states, i.e., its power matrix. Using the performance matrices of notional WECs, particularly an Oscillating Surge Wave Energy Converter (OSWEC) and a Heaving Point Absorber (HPA), we estimate optimal locations on the Italian coasts and highlight the advantages and disadvantages of the two approaches. The analysis shows the importance of a technology-based approach for the spatial planning of future wave power plants and highlights significant differences compared to the approach that can be used for the preliminary identification of sites for wind farms and, especially, for photovoltaic plants. We use the obtained results to introduce the MORE-EST platform, a novel web-based tool for straightforward estimation of wave resources and WECs productivity in European seas. The proposed platform is able to integrate information on wave resource assessment, bathymetry, marine space use and technological features, and represents a tool aimed at researchers, WECs developers, and policy makers.

Power control strategy of wave energy converter with a hybrid double-machine hydraulic energy storage and generating system

Wave energy converters (WEC) with the increasing capacity, which has reached a level of hundreds of kilowatts, would play a role in the connected microgrid. Due to the inherent fluctuation and randomness of wave energy, the unstable output power of WEC is a threat to the power balance of the microgrid. Machines start and stop periodically and the output power changes continuously and significantly. The previous study focused little on the power control of grid-connected WECs. In this paper, a power control strategy is proposed for WECs to achieve stable power output and regulation in various wave conditions. The power control strategy is based on a hybrid double-machine hydraulic energy storage and generating system composed of a controlled unit and an uncontrolled unit. The control strategy enables the stability control and the controllable regulation of power of WEC in various wave conditions. Simulation results of several wave conditions have validated the effect of the power control strategy. The power control strategy would contribute to the extensive deployment of WECs.

A high-resolution wave energy assessment of south-east Australia based on a 40-year hindcast

In this study, a third-generation ocean wave model (WAVEWATCH III; WW3) implemented on a high-resolution unstructured grid was developed to investigate wave energy in the south-east of Australia over the 40-year period from 1981 to 2020. The simulated wave power shows good agreement with values estimated from multiplatform satellite data. Thus, the modeled data were used to study statistics (mean conditions, seasonality, extremes, and long-term trends) of wave power in the domain, which show impacts of Southern Ocean swell and protection provided by the land mass of Tasmania. The results indicate increasing wave power trends, with the largest values in the southeastern part of the domain over the 40-year period. These positive trends are mainly a result of an increase in significant wave height rather than peak wave period. By utilizing the simulated wave properties, we estimated regional annual electric power at 14 coastal locations using 9 typical wave energy converters (WECs). To do so, we conducted a comprehensive analysis (seasonal variations, wave power roses, probability distributions, and bivariate probability distributions) at these locations. The results demonstrate that the western and southwestern coasts of the domain are promising generation sites but with large seasonal variability. The central and eastern coasts are protected by Tasmania, and exhibit more stable conditions but are far less energetic for electricity production. This study has critical implications for the region, which provides a benchmark for coastal WEC deployment.

Geospatial Analysis of Technical U.S. Wave Net Power Potential

Developing new technologies to utilize natural renewable energy resources and fluxes is critical to mitigate climate change and energy crisis. As a renewable energy resource, wave energy is more predictable and has a higher power density compared to solar and wind. However, the technology for wave energy harvesting is still relatively nascent. One of the major challenges as the sector developers is the lack of spatial–temporal representation of wave resources, or wave power generation, from a generic WEC.This paper proposes a novel Wave Net Power Assessment (WNPA) method by utilizing the theoretical Wave Energy Converter (WEC) power limits (including the radiation power limits, Budal’s limit, and gross wave power), and applies it to a decade of wave conditions across the USA East Coast, West Coast and Hawaiian Islands. The WNPA method assesses the wave resource from device point of view (unlike traditional gross wave resource assessment) and is generally applicable to WECs regardless of dimension, size, and degrees of freedom (DoFs). The geospatial application of the WNPA method allowed for the analysis of wave power production potential along U.S. coastlines and provides WEC developers meaningful data to make decisions about the best spatial region to deploy certain WECs. Numerical simulations are conducted for WECs with 5 different sizes, 3 different operating modes across the West Coast, East Coast, and Hawaii over 10 years. In addition, productivity, efficiency and gross power quality comparisons are made in terms of the size and degree-of-freedom for WECs deployed at certain ocean sites (e.g., PacWave).A few of the most important findings: (1) The net wave power is dramatically smaller than the gross wave power, which indicates the new WNPA method has a more conservative assessment of the wave power potential; (2) A heaving 10 m WEC is found to have the highest (compared to other sizes and degrees of freedom) absorption efficiency on the West Coast and Hawaii; (3) For smaller 2 m surging/pitching WECs, ocean sites on the East Coast (e.g., Diamond Shoals, NC) maximize power production. (4) There are distinct trade-offs between maximizing power or minimizing power quality and dependencies exists between the location of interest, the WEC size, and the priority degree of freedom. The proposed methodology can be utilized by WEC technology and project developers to conduct apriori preliminary analysis of WEC deployment locations and device characteristics.

Influence of directional wave spreading on a WEC device

Wave Energy Converter (WEC) performance is generally sensitive to the wave direction. So, it is important to include the effect of multi-directional waves in numerical modelling. A realistic representation of ocean waves should account for wave height and directional spreading parameters specific to the WEC deployment location. A high quality generalised directional distribution is dependent on the wave direction and frequency. Here we compare the power produced, the wave field, and the motion of the WaveSub device for different frequency-directional distribution cases. Directional spreading has been modelled using different model distributions such as the uniform cosine fourth, Mitsuyasu, Hasselman and Donelan-Banner. The hydrodynamic coefficients are computed for all wave directions using Nemoh. Then, the WEC-Sim code has been extended to add the capability to simulate different user selected frequency-directional spreading. The excitation force applied to each hydrodynamic body is updated to account for the effect of the directional spectrum. Results show that power produced is generally 10-20% lower than a single direction case. The motion of the device demonstrates the introduction of sway, roll, and yaw for the directional spreading simulations while the resultant wavefield is more uniform compared to the non-directional case. Computational time is significantly lower than comparable CFD approaches and this makes this method particularly effective.

Wave Energy Converter Deployments at the Navy's Wave Energy Test Site: 2015‐2019

AbstractA synopsis of wave energy converter (WEC) deployments at the U.S. Navy's Wave Energy Test Site (WETS), from the mid-2015 commissioning of the full three-berth site through 2019, is provided. This includes two deployments each of the Northwest Energy Innovations (NWEI) Azura device and the Fred. Olsen Ltd. BOLT Lifesaver, each with important modifications between deployments. The Azura was modified with a larger float and a heave plate, aimed at enhancing power performance, while the Lifesaver's second deployment addressed mooring challenges encountered in the first. Additionally, unique integration and deployment of a sophisticated environmental sensing system developed by the University of Washington, in which required power was drawn from the WEC itself, was achieved during this second Lifesaver deployment. A brief background of the site is included, as is a synopsis of two major efforts not directly related to WEC deployments—the development of a site-dedicated support vessel and work to redesign and make repairs to the WETS deep berth mooring systems, including the addition of a “no-WEC hawser” system to keep the moorings in tension between WEC deployments. Finally, a look ahead to WEC deployments planned in 2021‐2023 is provided.

Experimental investigation into 3D scour processes around a gravity based Oscillating Water Column Wave Energy Converter

Experimental investigations measuring both bed elevation changes and near-structure flow velocities were undertaken to investigate wave scour processes around a model Oscillating Water Column (OWC) Wave Energy Converter (WEC) for a range of incident wave conditions at approximately 1:20 scale. The experiment design was informed by a proposed 200 kW OWC WEC deployment site at King Island, Australia. The measurements provide the first experimental data on scour around an OWC WEC structure, and one of the most comprehensive experimental studies of wave scour around a large rectangular cross-section structure.High resolution scour erosion and deposition patterns were measured using an above-water laser-based system. For normally incident waves, scour holes were observed to develop on all four corners, and the size of the scour holes at the four corners increased with the Keulegan-Carpenter (KC) number. An additional scour hole/trench also formed along the upstream face of the OWC WEC due to the flow in/out of the OWC WEC internal chamber. Changing the incident wave propagation angle by 20° has a significant effect on the observed scour patterns, with reduced scour on the front and back corners but significant scour holes remaining on the other two corners. It is found that if the model is not sufficiently embedded into the sediment bed, scour can undermine a significant area under the structure, with quadrant shaped scour holes underneath the back corners extending to approximately 25% of the total base area, suggesting a risk of differential settlement in field conditions.

Impact of Climate Change on Wave Energy Resource in the Mediterranean Coast of Morocco

The increasing demand for energy and the impacts generated by CO2 emissions make it necessary to harness all possible renewable sources of energy, like wave power. Nevertheless, climate change may generate significant variations in the amount of wave energy available in a certain area. The aim of this paper is to study potential changes in the wave energy resource in the Mediterranean coast of Morocco due to climate change. To do this, wave datasets obtained by four institutes during the Coordinated Regional Climate Downscaling Experiment in the Mediterranean Region (Med-CORDEX) project are used. The future conditions correspond to the RCP4.5 and RCP8.5 scenarios from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The results show that projected future wave power is very similar to that of the present considering the whole area, although at some specific points there are slight changes that are more evident for the RCP8.5 scenario. Another remarkable result of this study is the significant increase of the temporal variability of wave power in future scenarios, in particular for RCP8.5. This will be detrimental for the deployment of wave energy converters in this area since their energy output will be more unevenly distributed over time, thus decreasing their efficiency.

Ocean wave energy potential along the west coast of the Sumatra island, Indonesia

The past few decades have seen considerable interest in exploration and research of ocean wave energy as a potential energy substitute for fossil-based fuel. In this study, a Wavewatch III spectrum wave model was driven to simulate significant wave height spanning for a period of 25 years, from 1991 to 2015 on the west coast of the island of Sumatra. The 25-year-average of wave energy shows some noticeable hot spots in certain areas that have a value of significant wave height up to 2.33 m and a wave energy 67.29 kW/m. These hotspot occurrences have a similar pattern as statistics collected for the seasonal characteristics that are associated with tropical monsoons with the average value of wave energy reaching its peak in an easterly monsoon season up to 98.21 kW/m, and the lowest average value occurring in the westerly monsoon season, lasting from December to February, with a prevalent value of 10 kW/m. Additional statistical parameters of possible wave energy site selections were considered, such as Coefficient of Variance, Monthly Variability Index, Optimum Hotspot Identifier, Wave Development Index, and accessibility to find the ideal location for wave energy converter deployment. These statistics give insight into potential prospective points for ocean-wave energy harvesting. Eight hotspots were finally selected based on the afore-mentioned statistical considerations and were further analyzed through wave energy characterization and obtained energy calculation through Pelamis, Archimedes Wave Swing, and Wave Dragon Wave Energy Converter power matrices. Finally, inter-annual variability and particular extreme events are discussed.

Numerical analysis of an Uppsala University WEC deployment by a barge for different sea states

Wave energy converters (WECs) have been deployed onshore, nearshore, and offshore to convert ocean wave movement into electricity. The exploitation of renewable energy sources has restrictions; in the case of wave energy, high installation, maintenance, and decommissioning costs have limited their commercial use. Moreover, these offshore operations can be compromised by safety issues. This paper draws attention to offshore operation safety of a WEC developed by Uppsala University. Specifically, this paper investigates what sea states are suitable for the safe deployment of a WEC from a barge. This study follows recommendations in DNV-RP-H103 for analysis of offshore operations, namely lifting through the wave zone. ANSYS Aqwa is used to find hydrodynamic forces acting on a typical barge, using frequency domain analysis. Based on these hydrodynamic simulation results and methodology given in DNV-RP-H103, tables are created to show the sea states that would allow for the safe installation of a WEC using a typical barge. Considered sea states have significant wave heights varying between 0 m and 3 m and the wave zero crossing periods varying between 3 s and 13 s. The WEC submersions are considered between 0 m and 7 m, i.e. when the WEC is in the air until it is fully submerged.

A Sensitivity Analysis of the Wind Forcing Effect on the Accuracy of Large-Wave Hindcasting

Deployment of wave energy converters (WECs) relies on consistent and accurate wave resource characterization, which is typically achieved through numerical modeling using deterministic wave models. The accurate predictions of large-wave events are critical to the success of wave resource characterization because of the risk on WEC installation, maintenance, and damage caused by extreme sea states. Because wind forcing is the primary driver of wave models, the quality of wind data plays an important role in the accuracy of wave predictions. This study evaluates the sensitivity of large-wave prediction to different wind-forcing products, and identifies a feasible approach to improve wave model results through improved wind forcing. Using a multi-level nested-grid modeling approach, we perform a series of sensitivity tests at four representative National Data Buoy Center buoy locations on the U.S. East and West Coasts. The selected wind-forcing products include the Climate Forecast System Reanalysis global wind product and North American Regional Reanalysis regional wind product as well as the observed wind at the buoys. Sensitivity test results indicate a consistent improvement in model predictions for the large-wave events (e.g., >90th percentile of significant wave height) at all buoys when observed-wind data were used to drive the wave model simulations.

Alternative approaches to develop environmental contours from metocean data

It is necessary to evaluate site-specific extreme environmental conditions in the design of wave energy converters (WECs) as well as other offshore structures. As WECs are generally resonance-driven devices, critical metocean parameters associated with a target return period of interest (e.g., 50 years) must generally be established using combinations, say, of significant wave height and spectral peak period, as opposed to identifying single-valued wave height levels alone. We present several methods for developing so-called “environmental contours” for any target return period. The environmental contour (EC) method has been widely acknowledged as an efficient way to derive design loads for offshore oil and gas platforms and for land-based as well as offshore wind turbines. The use of this method for WECs is also being considered. A challenge associated with its use relates to the need to accurately characterize the uncertainties in metocean variables that define the “environment”. The joint occurrence frequency of values of two or more random variables needs to be defined formally. There are many ways this can be done—the most thorough and complete of these is to define a multivariate joint probability distribution of the random variables. However, challenges arise when data from the site where the WEC device is to be deployed are limited, making it difficult to estimate the joint probability distribution. A more easily estimated set of inputs consists of marginal distribution functions for each random variable and pairwise correlation coefficients. Pearson correlation coefficients convey information that rely on up to the second moment of each variable and on the expected value of the product of the paired variables. Kendall’s rank correlation coefficients, on the other hand, convey information on similarity in the “rank” of two variables and are useful especially in dealing with extreme values. The EC method is easily used with Rosenblatt transformations when joint distributions are available. In cases where Pearson’s correlation coefficients have been estimated along with marginal distributions, a Nataf transformation can be used, and if Kendall’s rank coefficients have been estimated and are available, a copula-based transformation can be used. We demonstrate the derivation of 50-year sea state parameters using the EC method with all three approaches where we consider data from the National Data Buoy Center Station 46022 (which can be considered the site for potential WEC deployment). A comparison of the derived environmental contours using the three approaches is presented. The focus of this study is on investigating differences between the derived environmental contours and, thus, on associated sea states arising from the different dependence structure assumptions for the metocean random variables. Both parametric and non-parametric approaches are used to define the probability distributions.

A dual-functional wave-power plant for wave-energy extraction and shore protection: A wave-flume study

The fundamental roadblock toward commercial-scale wave power operations is cost. The main objective of this work was to address the cost challenge facing wave energy commercialization through cost-sharing with pile breakwaters to be built for shore protection. This was achieved in this study through a dual-functional wave-power plant for generation of wave-power electricity and protection against coastal erosion for sustainable coastal development. The dual-functional wave-power plant was formed by integrating oscillating-water-column (OWC) devices into a pile breakwater, with each pile being an OWC-pile equipped with a power take-off device. The power extraction efficiency and hydrodynamic characteristics of the dual-functional wave-power plant were measured in a wave flume under various wave conditions. An orifice was used at the top of the pneumatic chamber of each OWC-pile to simulate the power take-off device. To evaluate the performance of the power plant in wave power extraction and shore protection, the surface elevation and pressure inside the OWC chamber, as well as the scattered waves, were measured. It was found that comparing to a standalone OWC-pile device with an identical design and geometric characteristics, an OWC-pile in the dual-functional wave-power plant could achieve significantly larger power-extraction efficiency. Comparing to a pile breakwater with the same dimensions, the wave transmission and reflection of the dual-functional wave-power plant were both weaker, especially the wave reflection, which is beneficial for structure safety and shore protection. Based on the Froude’s law of similarity and an estimation of the effect of air compressibility at full scale, an evaluation of the performance of a dual-functional wave-power plant at full scale was also provided. The findings of this work promote close collaboration between wave-energy utilization community and the shore-protection community for commercial-scale deployment of wave energy converters and contribute to making wave energy economically competitive.

Spatial Environmental Assessment Tool (SEAT): A Modeling Tool to Evaluate Potential Environmental Risks Associated with Wave Energy Converter Deployments

Wave energy converter (WEC) arrays deployed in coastal regions may create physical disturbances, potentially resulting in environmental stresses. Presently, limited information is available on the nature of these physical disturbance or the resultant effects. A quantitative Spatial Environmental Assessment Tool (SEAT) for evaluating the potential effects of wave energy converter (WEC) arrays on nearshore hydrodynamics and sediment transport is presented for the central Oregon coast (USA) through coupled numerical model simulations of an array of WECs. Derived climatological wave conditions were used as inputs to the model to allow for the calculation of risk metrics associated with various hydrodynamic and sediment transport variables such as maximum shear stress, bottom velocity, and change in bed elevation. The risk maps provided simple, quantitative, and spatially-resolved means of evaluating physical changes in the vicinity of a hypothetical WEC array in response to varying wave conditions. The near-field risk of sediment mobility was determined to be moderate in the lee of the densely spaced array, where the potential for increased sediment deposition could result in benthic habitat alteration. Modifications to the nearshore sediment deposition and erosion patterns were observed near headlands and topographic features, which could have implications for littoral sediment transport. The results illustrate the benefits of a risk evaluation tool for facilitating coastal resource management at early market marine renewable energy sites.

Deployment and Maintenance of Wave Energy Converters at the Lysekil Research Site: A Comparative Study on the Use of Divers and Remotely-Operated Vehicles

Ocean renewable technologies have been rapidly developing over the past years. However, current high installation, operation, maintenance, and decommissioning costs are hindering these offshore technologies to reach a commercialization stage. In this paper we focus on the use of divers and remotely-operated vehicles during the installation and monitoring phase of wave energy converters. Methods and results are based on the wave energy converter system developed by Uppsala University, and our experience in offshore deployments obtained during the past eleven years. The complexity of underwater operations, carried out by either divers or remotely-operated vehicles, is emphasized. Three methods for the deployment of wave energy converters are economically and technically analyzed and compared: one using divers alone, a fully-automated approach using remotely-operated vehicles, and an intermediate approach, involving both divers and underwater vehicles. The monitoring of wave energy converters by robots is also studied, both in terms of costs and technical challenges. The results show that choosing an autonomous deployment method is more advantageous than a diver-assisted method in terms of operational time, but that numerous factors prevent the wide application of robotized operations. Technical solutions are presented to enable the use of remotely-operated vehicles instead of divers in ocean renewable technology operations. Economically, it is more efficient to use divers than autonomous vehicles for the deployment of six or fewer wave energy converters. From seven devices, remotely-operated vehicles become advantageous.

Identifying the Optimal Offshore Areas for Wave Energy Converter Deployments in Taiwanese Waters Based on 12-Year Model Hindcasts

A 12-year sea-state hindcast for Taiwanese waters, covering the period from 2005 to 2016, was conducted using a fully coupled tide-surge-wave model. The hindcasts of significant wave height and peak period were employed to estimate the wave power resources in the waters surrounding Taiwan. Numerical simulations based on unstructured grids were converted to structured grids with a resolution of 25 × 25 km. The spatial distribution maps of offshore annual mean wave power were created for each year and for the 12-year period. Waters with higher wave power density were observed off the northern, northeastern, southeastern (south of Green Island and southeast of Lanyu) and southern coasts of Taiwan. Five energetic sea areas with spatial average annual total wave energy density of 60–90 MWh/m were selected for further analysis. The 25 × 25 km square grids were then downscaled to resolutions of 5 × 5 km, and five 5 × 5 km optimal areas were identified for wave energy converter deployments. The spatial average annual total wave energy yields at the five optimal areas (S1)–(S5) were estimated to be 64.3, 84.1, 84.5, 111.0 and 99.3 MWh/m, respectively. The prevailing wave directions for these five areas lie between east and northeast.

Acoustic life cycle assessment of offshore renewables—Implications from a wave-energy converter deployment in Falmouth Bay, UK

Marine Renewable Energy is developing fast, with hundreds of prototypes and operational devices worldwide. Two main challenges are assessing their environmental impacts (especially in near-shore, shallow environments) and ensuring efficient and effective maintenance (requiring specialised ships and fair weather windows), compounded by the lack of long-term measurements of full-scale devices. We present here broadband measurements (10 Hz to 32/48 kHz) acquired at the Falmouth Bay Test site (FaBTest, UK) from 2010 onwards, for a 16-m ring-shaped Wave Energy Converter, in waters up to 45 m deep. This period covers baseline measurements, including shipping from the neighbouring English Channel, one of the busiest shipping lanes in the world (ca. 45,000 ship transits annually) and the full period of installation and energy production, including maintenance episodes. Acoustic signatures are measured as Sound Pressure Levels (e.g. for impacts) and time/frequency variations (for condition-based monitoring via Acoustic Emissions). They change through time, depending on weather and modes of operation. Long-term measurements are compared with modelling of potential variations in this complex environment and with laboratory experiments. These are used to outline the varying acoustic contributions through the life cycle of a typical wave energy converter, yielding insights for other wave devices in other environments.