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This is the final version. Available from Scientific Research Publishing via the DOI in this record. ; The purpose of this article was to analyze data associated with advances in wind energy across the United States. While governments, academia, and the private sector generally know patterns of wind turbine development (i.e. turbine size and capacity growing in recent years), there is no known independent, reliable, and/or updated summary of these variables. Using data collected by the Lawrence Berkeley National Laboratory and partners, this study used descriptive statistics to show turbine development and growth patterns from 1981-2019. The newly created United States Wind Turbine Database (USWTDB) represents the most comprehensive account of wind turbine information and was updated in January 2020. Variables I am interested in here are turbine manufacturer, state of project, turbine and project capacity, and turbine size. Findings provide empirical evidence to support the common, yet previously unrefined statements that wind turbines are growing larger in number, size and capacity. This growth is varied over spatial and temporal scales. I also provide evidence to show patterns of turbine manufacturing, with GE Wind dominating much of the US wind energy landscape today. I hope this work provides a timely resource for those interested in a variety of questions surrounding wind energy development in the United States. Perhaps more importantly, this analysis will hopefully inspire others to use what the USWTDB provides and answer larger questions surrounding wind energy futures

Intro -- WIND TURBINES PRICE TRENDS AND EXPORT OPPORTUNITIES IN CANADA AND LATIN AMERICA -- WIND TURBINES PRICE TRENDS AND EXPORT OPPORTUNITIES IN CANADA AND LATIN AMERICA -- CONTENTS -- PREFACE -- Chapter 1 U.S. WIND TURBINE EXPORT OPPORTUNITIES IN CANADA AND LATIN AMERICA∗ -- ABSTRACT -- INTRODUCTION -- PRODUCT AND GEOGRAPHIC COVERAGE -- KEY TERMINOLOGY -- U.S. MARKET UNCERTAINTY -- U.S. WIND INDUSTRY EXPANDED IN RESPONSE TO DOMESTIC MARKET GROWTH -- U.S. EXPORTS SIGNIFICANTLY INCREASED DURING 2007-11 -- CANADA COULD BECOME A SIGNIFICANT U.S. EXPORT MARKET -- Overview -- Market -- MARKET COMPETITION -- U.S. EXPORT OPPORTUNITIES -- MEXICAN MARKET PROVIDES OPPORTUNITIES FOR U.S. PRODUCERS -- Overview -- Market -- MARKET COMPETITION -- U.S. EXPORT OPPORTUNITIES -- VIBRANT BRAZILIAN MARKET OFFERS INCONSISTENT U.S. EXPORT OPPORTUNITIES -- Overview -- Market -- MARKET COMPETITION -- U.S. EXPORT OPPORTUNITIES -- AS OTHER LATIN AMERICAN MARKETS EXPAND, EXPORT OPPORTUNITIES ARE INCREASING -- Overview -- Market -- MARKET COMPETITION -- U.S. EXPORT OPPORTUNITIES -- CONCLUSION -- REFERENCES -- End Notes -- Chapter 2 UNDERSTANDING TRENDS IN WIND TURBINE PRICES OVER THE PAST DECADE∗ -- EXECUTIVE SUMMARY -- 1. INTRODUCTION -- 2. WIND TURBINE PRICE TRENDS IN THE UNITED STATES -- 3. WIND TURBINE PRICE DRIVERS -- 3.1. Labor Costs -- 3.2. Warranty Provisions -- 3.3. Turbine Manufacturer Profitability -- 3.4. Increasing Turbine Size and Energy Capture -- 3.5. Raw Materials Prices -- 3.6. Energy Prices -- 3.7. Foreign Exchange Rates -- 4. AGGREGATE IMPACT OF TURBINE PRICE DRIVERS -- 5. LOOKING AHEAD -- APPENDIX A - COMMODITY PRICE TIME SERIES DATA -- Raw Materials Price Data -- Energy Price Data -- APPENDIX B - TABLES 6 AND 7 FROM VESTAS LCA OF 1.65 MW V82 TURBINE (VESTAS 2006B) -- APPENDIX C - EXCHANGE RATE PASS-THROUGH -- REFERENCES -- End Notes

Due to the increase in electricity consumption in the world, the tendency to increase resource diversity in the electricity generation section has increased. With the decrease in the reserves of petroleum and derivative products used in traditional energy production systems, energy production has turned to renewable energy sources. Examples of renewable energy sources are the sun, wind turbines, and fuel cells. In order to provide sustainable energy production in wind turbines, the blades and body must be protected. In this study, the blade pitch angle control of the wind turbine is realized with the PID controller and the wind turbine is protected from high speeds. The coefficient control of the PID controller is determined by the PSO (Particle Swarm Optimization) and Ziegler Nichols method. Simulation was carried out in MATLAB/Simulink environment. It has been observed that the PID coefficient parameters optimized with PSO in the pitch angle control process reach the reference power value in a shorter time compared to the PID parameter values calculated with Ziegler Nichols. In addition, it was observed that the oscillation value was less at the reference power reached and the pitch angle increased.

Increasing awareness of the issues of climate change and sustainable energy use has led to growing levels of interest in small-scale, decentralised power generation. Small-scale wind power has seen significant growth in the last ten years, partly due to the political support for renewable energy and the introduction of Feed In Tariffs, which pay home owners for generating their own electricity. Due to their ability to respond quickly to changing wind conditions, small-scale vertical axis wind turbines (VAWTs) have been proposed as an efficient solution for deployment in built up areas, where the wind is more gusty in nature. If VAWTs are erected in built up areas they will be inherently close to people; consequently, public acceptance of the turbines is essential. One common obstacle to the installation of wind turbines is noise annoyance, so it is important to make the VAWT rotors as quiet as possible. To date, very little work has been undertaken to investigate the sources of noise on VAWTs. The primary aim of this study was therefore to gather experimental data of the noise from various VAWT rotor configurations, for a range of operating conditions. Experimental measurements were carried out using the phased acoustic array in the closed section Markham wind tunnel at Cambridge University Engineering Department. Beamforming was used in conjunction with analysis of the measured sound spectra in order to locate and identify the noise sources on the VAWT rotors. Initial comparisons of the spectra from the model rotor and a full-scale rotor showed good qualitative agreement, suggesting that the conclusions from the experiments would be transferable to real VAWT rotors. One clear feature observed in both sets of spectra was a broadband peak around 1-2kHz, which spectral scaling methods demonstrated was due to laminar boundary layer tonal noise. Application of boundary layer trips to the inner surfaces of the blades on the model rotor was found to eliminate this noise source, and reduced the amplitude of the spectra by up to 10dB in the region of the broadband peak. This method could easily be applied to a full-scale rotor and should result in measurable noise reductions. At low tip speed ratios (TSR) the blades on a VAWT experience dynamic stall and it was found that this led to significant noise radiation from the upstream half of the rotor. As the TSR was increased the dominant source was seen to move to the downstream half of the rotor; this noise was thought to be due to the interaction of the blades in the downstream half of the rotor with the wake from the blades in the upstream half. It was suggested that blade wake interaction is the dominant noise source in the typical range of peak performance for the full-scale QR5 rotor. Different solidity rotors were investigated by using 2-, 3- and 4-bladed rotors and it was found that increasing the solidity had a similar effect to increasing the TSR. This is due to the fact that the induction factor, which governs the deflection of the flow through the rotor, is a function of both the rotor solidity and the TSR. With a large body of experimental data for validation, it was possible to investigate computational noise prediction methods. A harmonic model was developed that aimed to predict the sound radiated by periodic fluctuations in the blade loads. This model was shown to agree with similar models derived by other authors, but to make accurate predictions very high resolution input data was required. Since such high resolution blade loading data is unlikely to be available, and due to the dominance of stochastic sources, the harmonic model was not an especially useful predictive tool. However, it was used to investigate the importance of the near-field components of the sound radiated by the wind tunnel model to the acoustic array. It was shown that the near-field terms were significant over a wide range of frequencies, and the total spectrum was always greater than that of the far-field component. This implied that the noise levels measured by the acoustic array represented an upper bound on the sound radiated to the far-field, and hence that the latter would also be dominated by stochastic components. An alternative application of the harmonic model, which attempted to determine the blade loading harmonics from the harmonics in the sound field was proposed. This inversion method utilised a novel convex optimisation technique that was found to generate good solutions in the simulated test cases, even in the presence of significant random noise. The method was found to be insensitive at low frequencies, which made it ineffective for inverting the real microphone data, although this was shown to be at least partly due to the limitations imposed by the array size. In addition to the harmonic models, an empirical noise prediction method using the spectral scaling laws derived by \citet*{Brooks_1989} was trialled, and was found to be capable of making predictions that were in agreement with the measured data. The model was shown to be sensitive to the exact choice of turbulence parameters used and was also found to require good quality aerodynamic data to make accurate noise predictions. If such data were available however, it is expected that this empirical model would be able to make useful predictions of the noise radiated by a VAWT rotor. ; This work was supported by the Engineering and Physical Sciences Research Council and Quiet Revolution Ltd.

Mixing suspensions is a very important hydraulic operation. The pitched six-blade turbine is a widely-used axial-flow impeller. This paper deals with effect relative impeller size and particle content on theefficiency of a pitched six-blade turbine at particle suspension. Two pitched six-blade turbines were used in model measurements of just suspension impeller speed. The ratios of the vessel to agitator diameter D/d were 3 and 4.5. The measurements were carried out in a dish-bottomed vessel 300 mm in diameter. The just suspension impeller speeds were measured using an electrochemical method, and were checked visually. A 2.5 % NaCl water solution was used as the liquid phase, and glass particles with four equivalent diameters between 0.18 and 0.89 mmand volumetric concentration from 2.5 % to 40% were usedasthesolid phase. The criterion values πs=Po√Fr'3(d/D)7 were calculated from the particle suspension and power consumption measurements. The dependencies of πs on particle content cv show that larger agitators are more efficient for higher particle content.

AbstractA key concern for property owners about the set up of proximate wind turbines is the potential devaluation of their property. However, there is no consensus in the empirical hedonic literature estimating this price-distance relationship. It remains unclear if the proximity to wind turbines reduces, increases, or has no significant effect on property values. This article addresses this ambiguity, combining 720 estimates from 25 hedonic pricing studies in a first comprehensive meta-analysis on this topic. Using Bayesian model averaging techniques and novel publication bias correction methods, I calculate an average of the reported estimates that is free from misspecification and publication bias. In economic terms, I find an average reduction in property values of $$-0.68\%$$

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0.68
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for properties 1.89 miles away, which turns to zero beyond 2.8 miles. Next to publication selection, the studies' ability to control for confounding factors such as pre-existing price differentials and spatial effects explains the variance in reported effect sizes.

In the last decade, the number of offshore wind farms has increased rapidly. Offshore wind farms are typically constructed in near-shore, shallow waters. These waters can be highly productive or provide nursery grounds for fish. EU legislation requires assessment of the environmental impact of the wind farms. The effects on hard and soft substrate fauna, seabirds and marine mammals are most frequently considered. Here we present Landsat-8 imagery that reveals the impact of offshore wind farms on suspended sediments. Turbid wakes of individual turbines are observed that are aligned with tidal currents. They are 30–150 m wide, and several km in length. The environmental impact of these wakes and the source of the suspended material are still unclear, but the wake size warrants further study. The underwater light field will be affected by increased suspended sediments and the turbid wakes could significantly impact sediment transport and downstream sedimentation. The question of whether such features can be detected by other remote sensors is addressed by a theoretical analysis of the signal:noise specification for the Operational Land Imager (OLI), the Enhanced Thematic Mapper Plus (ETM +), the Advanced Very High Resolution Radiometer (AVHRR/3), the Moderate-Resolution Imaging Spectroradiometer (MODIS), the Spinning Enhanced Visible and Infrared Imager (SEVIRI), the Flexible Combined Imager (FCI) and the Multispectral Instrument (MSI) and by a demonstration of the impact of processing OLI data for different spatial resolutions.

International audience ; The interest in renewable energy in the European Union has increased in the past years, thus efficient energy harvesting becomes more important. For the sector of wind energy, the consequences are growing sizes of wind turbines (WTs) and erections in remote places, such as off-shore. The resulting increase of operation and maintenance costs can be counteracted by structural health monitoring systems. Different methods have been developed for detection of damages in WT blades. However, the majority are not suitable for in-service measurements or require dense sensor arrays. This paper presents a damage detection method based on autocorrelations of response accelerations. The damage sensitive feature (DSF) is developed as the Mahalanobis distance between a baseline and a current vector of the autocorrelation coefficients. Firstly, the usefulness of the DSF is assessed by using the Bayes error rate. Secondly, statistical hypothesis testing is utilized for a decision about the structural state. The procedure is applied to numerical simulations of a single WT blade with a disbonding damage scenario. The time series of accelerations are obtained from transient simulations with a simplified aerodynamic loading. The damage detection results show to be sensitive for the chosen damage scenario and are promising for prospective developments of damage detection methods in WTs.

Funding: Scottish Government (GrantNumber(s): MMSS/002/15), Natural Environment Research Council (GrantNumber(s): NE/R015007/1). ; 1. Uptake of tidal turbine technology to generate renewable energy has been partly limited by poor understanding of ecological impacts, including the potential for collisions between cetaceans and rotating turbine blades. To address this concern, it is necessary to identify whether cetaceans behaviourally respond to operating turbines. 2. A turbine in Scotland was instrumented with hydrophones to detect cetacean vocalizations. A generalized additive model was used to investigate temporal variability in harbour porpoise presence close to the turbine. As there were incidentally periods when the turbine was not operating, it was possible to determine the effect of blade rotation, whilst accounting for the potentially confounding effect of tidal flow. 3. Harbour porpoise presence varied intra-annually, diurnally and with tidal state. Peak presence occurred during winter (September–February), at night and at high flow speeds on the flood tide. 4. Porpoises exhibited significant avoidance of the tidal turbine when it was operating; avoidance increased with flow speed, whereby mean porpoise presence was reduced by up to 78% (95% CIs, 51%, 91%) on the flood tide and up to 64% (95% CI, 3%, 91%) on the ebb tide. 5. The temporal variability in encounter rate in the present study highlights that collision risk assessments assuming static densities probably fail to capture the temporal variability of collision risk. Future studies should conduct long-term baseline monitoring to derive encounter rates at larger spatio-temporal scales and as a reference from which to measure change in habitat use. It is also critical that the generality of the avoidance rates presented here is assessed for other sites, turbine types, array sizes and cetacean species. As the tidal industry expands, it will be important to reconcile the benefits of avoidance responses from a collision risk perspective with potential ...

Wind power installations have become the second largest contributor to installation of electricity capacity in the European Union during the last decade. With this increase in production capability and size, technical and economical efforts should be directed to achieving the optimal structural performance during the life cycle. The deterioration processes, such as fatigue and corrosion, are typically affecting offshore structural systems. This damage decreases the system performance and increases the risk of failure, thus not fulfilling the established safety criteria. Inspection and maintenance actions are the most relevant and effective means of control of deterioration. The risk-based inspection planning methodology, based on Bayesian decision theory, represents an important tool to identify the suitable strategy to inspect and control the deterioration in structures such as offshore wind turbines. During the last decades, Risk Based Inspection (RBI) approaches have been applied in the oil and gas industry, giving a theoretical background that can also be applied for offshore wind turbines. Unlike other offshore structures, offshore wind turbines represent low risk to society due to their offshore location, no pollution risks and low human risks since they are unmanned. This allows the allocation of lower reliability level compared to e.g. oil & gas installations. With the incursion to water depths between 20 and 50 meters, the use of jacket and tripod structures represents a feasible option that improves technical aspects concerning structural robustness, dynamical performance and damage distribution. Structural components such as support structures, transition nodes and towers, have critical design elements or zones that need special thorough design concerning fatigue damage. In this work, a framework for optimal risk-based inspection and maintenance planning for Offshore Wind Turbines (OWT) is developed. Fatigue prone details (in cast iron and welded steel) at the jacket or tripod steel support structures are addressed. For wind farms additional efforts are needed when wake are to be accounted for. Wake effects imply increased turbulence and thus decrease in OWT fatigue life and performance. In wind farm locations and single/alone locations of offshore wind turbines are considered, and probabilistic models for assessment of the fatigue reliability are developed. Further a reliability-based approach to calibrate Fatigue Design Factors (FDF) for offshore wind turbine support structures is described. The FDF values are calibrated to a specific minimum reliability level and a particular inspection and maintenance strategy. Generally, lower FDF values are obtained for offshore wind turbines than for oil & gas structures and reduced FDF values are obtained when inspections are taken into account. Thereby, the basis is available for selecting a cost-effective fatigue design for offshore wind turbines substructures. Additionally, the integration of condition monitoring information to optimize the damage-mitigation activities is considered. This work is contemplating the updating through Bayesian statistics and Monte Carlo Markov Chain techniques. The new information and uncertainty is incorporated with an orthogonal polynomial approximation for assessment of fatigue reliability. ; Wind power installations have become the second largest contributor to installation of electricity capacity in the European Union during the last decade. With this increase in production capability and size, technical and economical efforts should be directed to achieving the optimal structural performance during the life cycle. The deterioration processes, such as fatigue and corrosion, are typically affecting offshore structural systems. This damage decreases the system performance and increases the risk of failure, thus not fulfilling the established safety criteria. Inspection and maintenance actions are the most relevant and effective means of control of deterioration. The risk-based inspection planning methodology, based on Bayesian decision theory, represents an important tool to identify the suitable strategy to inspect and control the deterioration in structures such as offshore wind turbines. During the last decades, Risk Based Inspection (RBI) approaches have been applied in the oil and gas industry, giving a theoretical background that can also be applied for offshore wind turbines. Unlike other offshore structures, offshore wind turbines represent low risk to society due to their offshore location, no pollution risks and low human risks since they are unmanned. This allows the allocation of lower reliability level compared to e.g. oil & gas installations. With the incursion to water depths between 20 and 50 meters, the use of jacket and tripod structures represents a feasible option that improves technical aspects concerning structural robustness, dynamical performance and damage distribution. Structural components such as support structures, transition nodes and towers, have critical design elements or zones that need special thorough design concerning fatigue damage. In this work, a framework for optimal risk-based inspection and maintenance planning for Offshore Wind Turbines (OWT) is developed. Fatigue prone details (in cast iron and welded steel) at the jacket or tripod steel support structures are addressed. For wind farms additional efforts are needed when wake are to be accounted for. Wake effects imply increased turbulence and thus decrease in OWT fatigue life and performance. In wind farm locations and single/alone locations of offshore wind turbines are considered, and probabilistic models for assessment of the fatigue reliability are developed. Further a reliability-based approach to calibrate Fatigue Design Factors (FDF) for offshore wind turbine support structures is described. The FDF values are calibrated to a specific minimum reliability level and a particular inspection and maintenance strategy. Generally, lower FDF values are obtained for offshore wind turbines than for oil & gas structures and reduced FDF values are obtained when inspections are taken into account. Thereby, the basis is available for selecting a cost-effective fatigue design for offshore wind turbines substructures. Additionally, the integration of condition monitoring information to optimize the damage-mitigation activities is considered. This work is contemplating the updating through Bayesian statistics and Monte Carlo Markov Chain techniques. The new information and uncertainty is incorporated with an orthogonal polynomial approximation for assessment of fatigue reliability.

[EN] the current work a computational study to evaluate the effect of the DPF downsizing on filtration efficiency is performed. The DPF is conventionally placed downstream of the turbine. However, its placement upstream of the turbine is growing in interest because of the benefits in specific fuel consumption, passive regeneration and aptitude to downsizing. Hence both pre- and post-turbine placement are considered in presence of clean and soot loaded substrates. An in-house 1D wall-flow DPF model for unsteady compressible flow is used. Volume reduction is approached considering diameter and length variation. In parallel, the cell density is also varied modifying the meso-geometry, i.e. cell size and porous wall thickness, imposing constant thermal integrity factor. The sensitivity to this last parameter is also analysed resulting its influence of second order in comparison to volume and cellular geometry effects. The lower Peclet number in the pre-turbine placement leads to higher filtration efficiency than post-turbine location comparing at the same DPF volume. Diameter based volume reduction provides slightly better results in filtration efficiency than length based reduction because of the way the filtration velocity field is varied. This general behaviour involves additional advantages to the potential for volume reduction of pre-turbine DPFs. Thus, different strategies with boundaries defined by volume reduction at constant filtration area or at constant specific filtration area can be approached looking for the best balance between fuel economy reduction and filtration efficiency increase provided by pre-turbine DPF placement. ; This work has been partially funded by FEDER and Government of Spain through Project No. TRA2016-79185-R. Additionally, the Ph.D. student E. Angiolini has been funded by a grant from Conselleria de Educacio, Cultura i Esport of the Generalitat Valenciana with reference GRISOLIA/2013/036. These supports are gratefully acknowledged by the authors. ; Serrano, J.; Bermúdez, V.; ...

This paper summarizes and introduces all vertical axis wind turbine (VAWT) projects where 100 kW or larger turbines have been installed. The basis for the review is both existing literature and personal correspondence with people once involved in the different developments. By citing the most relevant work for each project, the paper will also work as an information hub, making information on these projects more accessible. Since the 1970s, there have been several VAWT projects with installed turbines of significant size, either as attempts to commercialize VAWTs, or as university led research projects, or as a combination of the two. Most have involved Darrieus turbines built in North America during the 1980s. However, H-rotors, which have always been a favored concept in Europe, have seen a revival during the 2010s. The reason VAWTs have never fully challenged the success of the horizontal axis wind turbine (HAWT) is too broad a question to answer here. However, the reasons some VAWT projects have failed are addressed in this paper. Besides the fact that many of the prototypes had terminal failures, most of the installed medium or large-scale VAWTs have to some extent had problems with metal fatigue and durability. Additionally, a lack of long-term interest from governmental or private funders, as well as the introduction of reliable HAWTs, was a recurring theme from those involved in VAWT development, regarding the reason VAWTs so far have failed to succeed. © 2018 The Author(s)