345 research outputs found
Select Committee on Wind Turbines final report
No full textThe committee recommends the Commonwealth Government create an Independent Expert Scientific Committee on Industrial Sound responsible for providing research and advice to the Minister for the Environment on the impact on human health of audible noise (including low frequency) and infrasound from wind turbines.
Recommendation 1: final
6.5 The committee recommends that an Independent Expert Scientific Committee on Industrial Sound (IESC) be established by law, through provisions similar to those which provide for the Independent Expert Scientific Committee on Coal Seam Gas and Large Coal Mining Development.
6.6 The provisions establishing the IESC on Industrial Sound should state that the Scientific Committee must conduct \u27independent, multi-disciplinary research into the adverse impacts and risks to individual and community health and wellbeing associated with wind turbine projects and any other industrial projects which emit sound and vibration energy\u27
Information paper: evidence on wind farms and human health
No full textThis Information Paper provides Australians with a summary of the evidence on possible health effects of wind farms in humans and explains how NHMRC developed its summary based on the findings of independent reviews of the evidence. It is intended for use by any person or group interested in wind farms.
Wind farms in Australia
Wind turbines use rotating blades attached to towers to convert wind energy into electricity. A group of wind turbines is known as a wind farm and may be located on land or offshore. Wind turbine design has evolved over the last 20 years to enable better harnessing of wind energy.
Wind farms have been promoted as a viable and sustainable alternative to traditional, non-renewable forms of energy production. Since the introduction of the Renewable Energy Act 2000, the number of wind farms in Australia has grown substantially. At the end of 2013, there were 68 wind farms across the country and more were being constructed or planned.
Why NHMRC is conducting this work
NHMRC is responsible for ensuring that Australians receive the best available, evidence-based advice on matters relating to improving health and to preventing, diagnosing and treating disease. Concern about the effects on health from living near a wind farm has been expressed by some members of the community. Therefore, NHMRC examined the evidence on health effects associated with exposure to specific emissions from wind farms — noise, shadow flicker and electromagnetic radiation.
The current investigation of the potential health effects of wind farms builds upon NHMRC’s previous work in this area. In 2010, NHMRC’s Public statement: Wind turbines and health was published, with supporting evidence from Wind turbines and health: A rapid review of the evidence. The 2010 NHMRC Public Statement concluded that there “is currently no published scientific evidence to positively link wind turbines with adverse health effects”. Due to the limited amount of published scientific literature, NHMRC committed to carrying out a more extensive search for evidence.
This Information Paper provides an update to NHMRC’s previous work in this area. It is based on a comprehensive review of the available scientific evidence following well-established systematic review principles, which provide the most rigorous process for identifying and critically appraising evidence.
In Australia, responsibility for regulating the planning, development and operation of wind farms lies with state, territory and local governments. The outcomes of NHMRC’s review may assist these organisations to make decisions about the regulation of wind farms.
NHMRC’s review of the evidence will enable well-designed and targeted research to be undertaken in areas that have been identified as gaps in the evidence base
Analytical solution for the cumulative wake of yawed wind turbines
No full textThis thesis sets out to improve the physical grounding and predictive accuracy of cumulative wake effect modelling within wind farms with yawed turbines. It derives an analytical solution for the lateral velocity field within a wind farm and compares its predictions to those of computational fluid dynamics.A parametric study is performed using a Reynolds-averaged Navier-Stokes (RANS) solver with the k-ε-fP turbulence model, Joukowsky rotor-based actuator disc, and neutral log-law inflow within the PyWakeEllipSys framework to determine the effects of yaw angle, thrust coefficient, and turbulence intensity on the lateral wake.The results of this parametric study are used to solve an approximate form of conservation of mass and momentum in the lateral direction for a turbine within a wind farm. The solution is an explicit equation predicting the lateral velocity distribution and lateral wake deflection within a wind farm of arbitrary layout and with arbitrarily yawed turbines. It also provides a first mathematical proof of secondary wake steering. The solution is implemented in Python and used to predict the velocity distributions in several wind farm cases, including for a single turbine, a two-turbine arrangement, and two wind farm cases with aligned and staggered layouts. These predictions are then compared against those of the RANS setup. The model significantly overestimates wake deflections unless corrected to neglect the near wake, but the corrected version shows promise, particularly in predicting wind farm power of the staggered layout, where the prediction is 19% closer to the RANS result than the prediction that considers lateral velocities equal to zero.https://github.com/NilsGaukroger/Analytical-solution-for-the-cumulative-wake-of-yawed-wind-turbinesEuropean Wind Energy Masters (EWEM) | Rotor Design Trac
Design in principle for flexible fully assembled wind turbine installation: Offshore installation of wind turbines
No full textWind turbine industry is growing and future predictions are promising. However, a shortage of installation vessels could influence this growth in offshore wind industry. Commonly, wind turbines are installed in components using a jack-up vessel. Occasionally, wind turbines are installed fully assembled. The center of gravity of a fully assembled wind turbine is relatively low and thus lifting above the wind turbine is not necessarily for fully assembled wind turbine installation. Wind turbines can be installed fully assembled using cranes in twin lift configuration to reduce required lifting capacities. The flexibility and scalability of the vessel depends on the location of the cranes on the vessel. Different vessels can install wind turbines with their advantages and disadvantages. To identify these solutions, principles are proposed and compared with state-of-the-art vessels for wind turbine installations. A morphological analysis is used to identify promising solutions for fully assembled wind turbine installation. Eight concepts are compared in a scenario comparison with varying distance between nearby marshalling ports and the wind turbine park location. Several solutions show subsequent improvement in installation rates. One new concept, the PWT installation vessel, shows overall improvement in installation rates. This solution, developed by the author of this report, is proposed for flexible and scalable fully assembled wind turbine installation.Mechanical Engineering | Transport Engineering and Logistic
The Impact of Wind Shear and Turbulence on the Loads and Performance of Wind Turbines
No full textOperating in real-world conditions, modern large capacity wind turbines often experience off-design situations, enduring dynamic loads characterized by complex unsteady aerodynamics. Key among the challenges in predicting these dynamic loads is understanding the effects of wind shear and turbulence, both individually and in their complex interplay. This research aims to shed light on these phenomena, with an emphasis on their impacts on wind turbine fatigue loads and power production.The research first provides an in-depth analysis of the influence of atmospheric stability on wind shear profile, aiming to extend the wind shear profile beyond the range of LiDAR measurements. Recognizing the limitations of existing power law and logarithmic law extrapolation methods, the study validates the use of multiple stability correction functions for accurate wind speed extrapolation. Subsequently, the research delves into the intricate effects of wind shear and turbulence on fatigue loads at the blade root of wind turbines, leveraging aeroelastic simulations. This research addresses the challenge of assessing wind turbine suitability for sites where one or several wind climate parameters surpass their design class values. It investigates the potential of the Response Surface Methodology (RSM) to estimate site-specific fatigue loads, a process that conventionally requires extensive aeroelastic simulations. This research also extends the scope to include the assessment of site-specific wind turbine power curves, validating the use of the Rotor Equivalent Wind Speed (REWS) and turbulence renormalization methods. Both methods show promise in estimating site-specific wind turbine power curves using a power curve measured under varying wind conditions.In essence, this study emphasizes the significant impact of wind shear and turbulence on the performance and longevity of wind turbines. By shedding the light on potential improvements, this study hopes to contribute towards accurate power output and fatigue load assessments.Electrical Engineering | Sustainable Energy Technolog
Modelling methodology for distributed wind turbines based on IEC and WECC: single turbine representation vs a combined model
No full textThe use of renewable energies has been growing in a considerable way in the world. Until 2017, 18% of European Union’s total installed power generation capacity was wind power capacity. The level of grid penetration of wind turbines has also increased significantly in the Netherlands. This high level of penetration of wind energy affects the behavior of the system during an event (such as a short circuit), which is not the same that with only conventional generation in the system. The level of detail in the dynamic network model of a transmission system becomes of great importance when a big amount of wind energy is connected to the electrical system. In the current dynamic model of the Netherlands transmission system, negative load is used to represent wind turbines, however, this could be no longer sufficient if more wind turbines are connected to the grid.The purpose of this Master Thesis Project is the study and analysis of voltage response of wind turbines models based on the IEC 61400-27-1 standard and the WECCWind Plant DynamicModeling Guidelines, both of them currently implemented in several softwares.This project proposes a modelling methodology for distributed wind turbines, using a single turbine representation and a combined model instead of a negative load directly connected to the grid.PowerFactory and PSSE softwares are used for the modelling of wind turbines, allowing to compare the models based on the IEC standard and the models based on the WECC guidelines respectively.For the simulations performed in these two softwares, parameters suitable for comparing both of them are proposed. Besides, an analysis on the differences between both models is provided.The parameters proposed are used later on for the modelling of distributed wind turbines in the grid.The methodology for the modelling of distributed wind turbines was proposed and analysed using a region in the Netherlands as case of study and the PSSE software (widely used by transmission system operators) with the generic parameters proposed in the previous analysis.The proposed methodology and parameters show a more realistic behavior of the wind turbines compared to the use of a negative load. It also provides a grouping proposal depending on the types of distributed wind turbines connected to the grid. In some cases, when the wind energy connected to the system has low impact, the use of a detailed model instead of a negative load is not very representative. Therefore, this project proposes a calculation for the impact that wind energy has in each substation, making easier to decide what is the most suitable level of modelling detail.Electrical Engineerin
A whole-energy system perspective to floating wind turbines and airborne wind energy in The North Sea region
No full textIn light of the energy transition to a fossil-free energy system, Europe is experiencing a colossal shift toward renewable energy generation. To facilitate the rapidly growing demand for clean energy, new technologies, and resources are being investigated. Airborne wind energy (AWE) and floating wind turbines have the potential to unlock untapped wind resource potential and contribute to the balancing of the system in unique ways. So far, the techno-economic potential of both technologies has only been investigated at small scale, while the most significant benefits will likely play out on a system scale. Demonstrating the economic feasibility and additional benefits of emerging technologies in an energy system context is vital to accelerate political traction and funding.This research aimed to find the main system-level trade-offs involved with integrating AWE and floating wind turbines in a highly-renewable future energy system. To do so, a modelling workflow was developed that consists of future costs and performance estimation, wind resource assessment and integration into a high-resolution large-scale energy system cost-optimization model, based on the Calliope modelling framework. The investigated region contains 10 countries in the North Sea region. The wind resource and system balancing are hourly-resolved. Key findings include:Onshore AWE significantly outperforms onshore wind turbines due to higher wind resource availability.The main limiting factor in large-scale onshore AWE deployment is the spatial energy density.Offshore AWE shows highly identical performance compared to offshore wind alternatives.Deployment of offshore AWE is mainly cost driven.Floating wind turbines demonstrate great potential because of the high capacity factors that can be achieved in high wind resource areas where conventional offshore wind is not technically feasible.Offshore wind potential in general strongly depends on available onshore technical potential.The outcomes show significant potential for both emerging technologies that could be realized in the near future. This study provides first exploratory findings that lay the foundation for future studies in the context of this research topic. Multiple directions for follow-up research have been identified to quantify this potential in more detail.Sustainable Energy TechnologyElectrical Engineering | Sustainable Energy Technolog
Optimal Feedforward Control for Offshore Wind Turbines During Grid Faults
No full textDue to the increased share of (offshore) wind turbines, more stringent power requirements have been established. Importantly, the low-voltage ride-through requirement states that a wind turbine must remain connected to the electrical grid after a short intermittent grid fault. In the industry and academia many solutions have been proposed, but these are limited by requirements of detailed system knowledge, lack of optimality guarantees, or no testing on high-fidelity models. Therefore, two Iterative Learning Control (ILC) algorithms are presented aimed to solve these issues. The ILC algorithms apply model-free learning based on iterations. Shown is that these ILC algorithms can yield improved performance on a low- and high-fidelity models, with fast convergence of the 2-norm of the output error. The major contributions of this work lie in the application of ILC on grid fault control for wind turbines and in the extension of the norm-optimal ILC to include input constraints using optimisation methods.Mechanical Engineering | Systems and Contro
Dynamic Load Prediction in Offshore Wind Turbines
No full textThe rapid development of the wind industry over the past few years has pushed turbine manufacturers to meet the growing energy demands by designing and producing large scale wind turbines.This also means development of larger monopile foundations for the foundation designers in the case of offshore wind turbines.\ Generally, the turbine tower and monopile are modeled together and the loads from the rotor-nacelle assembly are provided by turbine manufacturers.\ The offshore industry is now showing more interest in extracting the loads from the top mass by developing their own tools in order to reduce the dependency on the manufacturers. In order to aid in this process, the present master thesis aims to develop a linear model based on the concept of Dynamic Substructuring which employs a set of equations to compute the interface forces using the kinematics.\ Furthermore, the developed prediction model is used to analyze the loads occurring at the interface between the rotor-nacelle assembly and the tower for different wind speeds and wind conditions.Consequentially, the model was found to produce acceptable loads at higher wind speeds for selected degrees of freedom at the interface while failing to do the same for other degrees of freedom.The results in time domain were converted to the frequency domain to analyse the resonance.The influence of resonance on the interface degrees of freedom was found to be higher at wind speed below the rated condtion.\ These findings can be used as a basis to conduct further investigations into the application of numerical integration concepts to aeroelastic structures.Electrical Engineering | Sustainable Energy Technolog
The Jack-up frame: A novel installation method for large offshore wind turbines
No full textThe offshore wind industry is entering a new level of maturity. Announcements of bigger offshore wind turbines, the interest in new locations for offshore wind farms in harsher environments and the appearance of zero subsidy bids are proof of a rapid development. The next generation turbines are expected to be significantly larger and heavier compared with the current operating turbines. This poses new requirements for safe and efficient installation, requirements that go beyond the capabilities of existing jack-up installation vessels and equipment. Therefore, to avoid bottlenecks for future development, new installation equipment is needed. The goal of this thesis is to find an efficient way for installation of future offshore wind turbines with a rated power of up to 20MW.The characteristics of these large size turbines were studied by examining the relation between the rated power and the rotor diameter of operating offshore wind turbines. The derived dependencies between the desired power and the required area of the rotor were validated with data from announced turbines. Extrapolating these dependencies has resulted in a prediction for the 20MW turbine of a rotor diameter of 250 metres, a hub height of 160 metres above sea level and a nacelle with a mass of around 1100 tonnes.To be able to develop new concepts for the installation of these turbines, interviews were conducted with industry experts and criteria were derived. Next, upscaling of the equipment of the current jack-up vessel was investigated, already existing concepts were reviewed and new concepts were developed. Based on the set criteria, a suitable installation concept was chosen. The chosen concept eliminates the need for lifting the heaviest component (the nacelle) to the highest height (hub height) by dividing the tower of the turbine into several segments. It consists of a temporary installation frame that can be placed from a jack-up vessel on top of the foundation of an offshore wind turbine. While installing the frame on the foundation with a crane, the nacelle, hub and blades are mounted together on the deck of the jack-up vessel, forming the rotor nacelle assembly (RNA). Then, the RNA together with the first segment of the tower is placed in the frame, skidded sideways and brought up by a built-in jacking mechanism in the frame. It needs to be brought up 45 metres, so the following segment of 40 metres can be skidded underneath. While jacking the first segment, the following segment is placed next to the lift frame and prepared to be skidded. After the skidding of the next segment is finished, the previous segment is lowered on top of the other segment and they are mounted together. While fastening the connection, the jacking mechanism is lowered by recycling the strokes so it can start lifting the next segment. This is repeated until the complete turbine has been installed. When all the tower segments are installed, the turbine can be commissioned and the frame is retrieved.Optimisation of the concept has been performed by highlighting the logistical process regarding placement of the frame, lifting of the turbine and retrieval of the frame. A concept design is presented that can install the future offshore wind turbines with a rated power of up to 20MW. It is able to install the large size turbines faster compared to upscaling the existing installation equipment, it can be used for several turbine sizes and it only requires small modifications on the design of an offshore wind turbine.The concept consists of a jack-up vessel from where the installation is performed offshore. This was preferred over a floating vessel, since movement of the jack-up vessel is reduced significantly when lifted out of the water. For wider applicability of the developed concept, for example on a free floating vessel, (non jack-up), further research is required to reduce motions between the turbine and the foundation.<br/
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