This research, a part of more extensive research, presents pre-feasibility and unit sizing analysis of a hybrid system equipped with renewable energy resources in Tabriz, Iran (46°26/E, 38°06/N). This case study examines a GSM telecommunication station as a stand-alone load system. Renewable energy resources include photovoltaic (PV), a wind turbine as primary resources and fuel cell, and a battery stack as backup and energy storage systems, while an electrolyzer is used to provide the required hydrogen in the fuel cell system. Feasibility analysis and unit sizing are conducted based on climatic data such as solar irradiance and wind speed to derive an optimal model during the study. HOMER software is used to simulate the feasibility analysis, measure the size, and optimize the system. The results showed that the hybrid system performs cost-effectively. According to wind energy data and fuel-cell costs, sensitivity analysis is conducted. The load is a stand-alone GSM station that consumes 60kW per day with a maximum of 3.8kW per hour. This analysis showed that wind, PV, electrolyzer, battery, and fuel cells are not currently the best solutions. Shortly, according to improved prediction in fuel-cell technology, it is expected that this source as a backup will be the best option because it has decreased fuel-cell costs up to 65 percent. Some criteria such as size, application, and cost, have been mainly examined. These results provide excellent opportunities for this hybrid system. The result shows using fuel cells in a hybrid system is not affordable by considering current fuel cell price, and the main suggestion hybrid system configuration is PV, wind turbine, and battery, while for the nearby location of Tabriz by decreasing wind speed, using wind turbines is not feasible and more PV array should be added to the system.

Sustainable energy utilization on Mars is fundamental for the success of habitation on Mars. The two sustainable energy sources for In-Situ Resource Utilization (ISRU) with the highest potential for implementation on Mars are solar and wind. Unfortunately, the former cannot provide a reliable continuous source of energy for multiple reasons. Accordingly, wind energy is presented as a viable solution, or as a strong potential complement to solar energy. The authors investigate different sites on Mars by evaluating the available wind resources to select the most feasible location in terms of energy yield and other critical habitability criteria. This work is conducted by applying the General Circulation Model (GCM) simulation, this particular analysis of wind harvesting feasibility on Mars will be studied by employing the Mars Climate Database (MCD) model. In addition, this novel research provides a systematic approach for future energy harvesting projects on Mars. Moreover, it evaluates different potential wind turbine design concepts applicable for the Martian ISRU. The results of this research lay the foundation for future energy utilization necessary for habitation to thrive, as well as it will be a key for future exploration missions. Ultimately, this will enrich our understanding of wind turbine systems.

Glass Fiber Reinforced Plastics (GFRP) have been used in many fields such as aerospace, automotive and wind energy sectors. During their manufacturing processes, some defects such as dry spots and air pockets may develop in impregnated fabric, especially, when metallic inserts are used. To evaluate the interface between parent and repaired parts, an experimental study is performed to investigate its effect on the mechanical properties and structural integrity. To compare the response of the re-infused and intact samples, several tensile and bending tests were performed for uniaxial glass reinforcing fabric with tailored orientation for the interface between the intact and repaired regions. The results showed that for the tensile tests, repaired specimens with interfaces having 90° and 45° orientations w.r.t. loading direction were able to recover 80% and 73%, respectively, from the tensile strength of samples produced by vacuum infusion technique. However, for bending tests, the flexural strength was recovered by almost 90% and 72% for both interfaces, respectively. Based on visual inspection, each type of tested specimen has a typical dominant failure mode. For re-infused samples, the properties of the parent and repaired laminates determine the failure location.

In this paper, the stochastic optimization of a horizontal-axis composite wind turbine blade is performed. Wind energy has become widely popular in recent decades as an alternative source of energy and many studies have been devoted to finding an optimal wind turbine blade using deterministic optimization. However, the actual responses of the wind turbine blade such as power generation are affected by the stochastic nature of wind, uncertainties in material properties and modeling parameters, and so on. This can have an undesirable impact on the performance and reliability of blades, which demands the consideration of uncertainties during optimization. To this end, a surrogate-based stochastic optimization of a wind turbine blade considering the influence of randomness in wind speed on power generation was studied. A slight gain in average power over the baseline blade was obtained and it demonstrated the promise of the presented framework for the design of wind turbine blades.

Enhancing the thermal conductivity of phase change materials (PCMs) is attracting attention for renewable energy applications such as solar, geothermal and wind energy. The use of energy storage can significantly improve the efficiency of renewable energy systems due to their intermittent nature. Latent heat thermal energy storage is a particularly attractive technique due to its high capacity can store energy at near constant temperature corresponding to the phase transition temperature of the PCMs. The present work aims to overcome this undesirable property of low thermal conductivity by manipulating metal fillers including nickel (Ni) nanoparticles/nanowires within the paraffin wax to improve its thermal property. In present work, a finite element method (FEM) was developed to obtain a fundamental understanding of the behavior of the Ni particles/wires under a uniform magnetic field by predefined magnetic pads. In the model, the Navier-Stokes equations were introduced as governing equations for the fluid field and the magnetic field was simulated by Maxwell’s equations. Then the motion of single Ni wire was modeled and the translation and rotational movements of the wire was studied in this paper.

This work presents the design and analysis of a novel wind energy harnessing system that makes use of wind defecting structures to increase the ambient wind speed at geographic locations with relatively low wind speed. The system however reacts to highspeed wind conditions by altering the profile of the wind defecting structure in order to eliminate wind speed amplification attribute of the system, thereby protecting the wind turbine assembly at high speed wind conditions. Although increasing the wind speed is advantageous at geographic locations that the wind speed is typically low; however, from times to time, there could be sustained high-speed wind conditions at the same locations that may damage the wind turbine systems that take advantage of the wind defecting structures. The present work disclosed a wind deflecting structure formed by at least two sail-like partial cylindrical structures that are supported atop of a tower-like foundation in a symmetric arrangement, where one or more wind turbines can be installed in the space between the two partial cylinders. The two partial cylinders, each substantially in form a quarter cylinder is made of plurality of parallel ribbed-like bars, hereafter referred to as “bars” with a flexible thin material that are mechanically supported by the bars. The bars are oriented in a direction perpendicular to the ground; allowing the wing deflecting structures to accept horizonal axis or vertical axis turbines in the space between them. The function of the bars is to allow the thin material, attached to them, to assume a curved configuration substantially in the form of a quarter cylinder. The apparatus is equipped with wind speed monitoring devices, and power source and power transmission means, such as cable-pulleys, chain-sprockets, gears, or mechanical linkages that all work in concert to deploy or stow the thin material along the vertical rods depending to the magnitude of the prevailing wind speed. Preliminary computational fluid dynamics analyses have shown that the wind deflecting structure proposed here in amplifies the wind speed by a factor of 1.65.

Understanding and minimizing the uncertainties in the wind energy field is of high importance to reduce the reliability risks and financial risks of wind farm projects. The present work aims to observe the levels of uncertainty in modeling the wake effect by attempting to perform statistical inference of a wake parameter, the wind speed deficit. For this purpose, an uncertainty propagation framework is presented. The framework starts by randomly sampling mean wind speed data from its probability density function (PDF), that is fed an inflow model (TurbSim), resulting in random full-flow fields that are integrated into an aeroelastic model (FAST), which results in the variability of the power and thrust coefficients of a wind turbine. Such coefficients and wind data, finally, fed the wake engineering model (FLORIS). The framework ends with the determination of the 95% coefficient intervals of the time-averaged wind speed deficit. The results obtained for the near and far wake regions introduce fundamentals in estimate the uncertainty in wind speed deficit of a single wind turbine wake and concludes that a systematic uncertainty quantification (UQ) framework for wind turbine wakes may be a useful tool to wind energy projects.

Remotely operated vehicles, ROV, are highly versatile robotic systems, which are currently the best alternative to carry out deep-sea tasks, that otherwise could compromise the safety of human lives. These vehicles are commonly used by several industries such as offshore oil companies, offshore wind energy companies and environmental organizations. These underwater vehicles may be classified as Free-Swimming Systems, FSS, or Tether Management Systems, TMS. Tether Management Systems use the cable to transmit data and steering commands, and as a mean for power supply. It is known that the cable has a strong influence on the dynamics and maneuverability of a ROV. To improve the motion accuracy and stability of the control of a ROV, it is necessary to understand the nature and to estimate the value of the mutual reaction forces between the ROV and the cable. This research seeks the modeling of the overall underwater tethered vehicle, by iteratively coupling the results from the finite element analysis, FEA, of the cable with the dynamic model of the ROV, as obtained by using the standard Newton-Euler formulation. Morison equation is employed to obtain the cable transient response. In this work, the ROV tether is defined as a flexible, slender cylinder, with circular cross section and made of a material with nonlinear elastic behavior. The cable is assumed to be in a specific extended initial configuration, with one of its ends fixed in ground. The FEA analysis of the cable is performed with the help of the commercial software COMSOL Multiphysics. A commercial small ROV is selected as the case study to apply the Newton-Euler method, considering the location of its actuators and other actual parameters such as mass, matrix of mass moments of inertia and drag coefficients. To include the cable forces into the dynamic model of the ROV, it is necessary to perform an iterative process between the cable analysis results and the ROV open loop response. The modeling approach starts with an FSS system initial velocity, which is fed into the cable FEA analysis. Both analyses are iterated, following a mutual feedback scheme, until results converge, obtaining the complete tethered vehicle model. The main achievement of this investigation is to observe the cable influence on the ROV, providing results that prove to be extremely useful for future work on the control system design, taking into account the disturbances introduced by the cable.

There is a growing need for an environmentally friendly source of energy that can replace the conventional fossil fuel energy. This is because the effects of global warming is becoming very obvious, as evidenced by the severe flooding that occurred in the U.S. in 2017 1 . Two notable solutions to this dilemma are wind and solar energy. Solar powered devices derive their energy from the sun, hence, the amount of energy is severely limited during the cold months of the year when solar intensity is typically low. Wind energy, on the other hand is most prevalent during this cold months when the wind speed is typically higher. The aim of this research is therefore to conduct a comprehensive assessment of wind energy potential in Michigan City, Indiana, United States. This information will allow homeowners and investors with interest in alternative energy to make critical decisions in this regard. The study was conducted using wind speed data collected over a five-year period from 2012 to 2016. In this work, we have also determined the best method for evaluating the Weibull parameters (shape and scale factors) for wind data analysis. The site average wind speed ranged from 4m/s to 9m/s with a peak in the winter months and minimum in the summer months. The wind speed with the maximum energy at the hub height varied between 5.84 m/s in August 2016 to 12.79 m/s in October 2012 with annual average speeds between 8.85 and 9.35 m/s and a five-year average of 9.13 m/s. The prevailing wind speed was within the range of 4–8m/s and strongest on the Southern part of the site especially in the South Southeastern direction. Consequently, siting a wind turbine on the Southern part of the City would generate more energy than on any other direction. Among the turbines analyzed, ITALTECH 250 will yield the maximize energy production with a capacity factor of 0.385 and average annual energy production of 840 MWh/yr. The results presented in this work proves the great potential for investments in wind energy in Michigan City.

Nowadays a large interest in the public and private sector is dedicated in generating electricity using renewable resources. Thus, over 60,000 MW is produced worldwide by using the wind energy. These systems are generally composed of power plants formed from 2–3 to several tens, hundreds of wind turbines with rotating blades that reach heights over 160m. The number, the height, and the rotation of these wind turbines represent technical challenges for the radar system efficiency and accuracy. They should be assessed carefully, in each case, to ensure that it maintains an acceptable level of the air space surveillance capability. The research paper presents the influence of the wind power farms on the air radars especially in cases of surveillance area, both for the primary radars and the secondary radars. There are differences between the interference between the wind turbines and radars functioning, depending on the types of radars. In the last decades in Romania is a permanent effort to increase the number the wind farms built, or in the process of being built, but also referring at the number of wind turbines in these parks and their physical dimensions. This paper focuses on the effects of the wind farms on the radars efficiency, and their potential impact on the ability of airspace surveillance. This results in a concise and transparent reference guide for developers of wind farms when assessing the impact of wind turbines on aerial surveillance systems. Specialists are relatively unanimous in their opinion that, in order to make an assessment of the impact of the wind farms on the radars must be defined at least three areas corresponding to different levels of the technical expertise. They must be combined with the influence of the wind farms on the ability of the radar to fulfill the mission, why they were installed, assuming that it is necessary to create an exclusive protection area. First, are discussed briefly the principles of the radar’s operation, depending on their type: primary and secondary surveillance radars. Further, are estimated the induced reflections by the wind power plant on the radar system. If the number of false targets generated by the reflections from wind turbines is too big, so it exceeds the processing capacity of the radar, the operational capacity will suffer. There are presented some theoretical aspects, followed by some cases where the proper functioning of the primary and secondary radars is affected. The model is tested in field, at two different distances, with airplanes and helicopter flying at different altitudes, with radar placed near the wind power plant Fantanele – Cogelac, the biggest in Romania. Finally, is estimated the area necessary to assure proper functioning of radars. Some conclusions and references are presented.

Wind energy is a clean, renewable, and fast-growing energy source for power generation. However, the noise issue, especially the aerodynamic noise, has become a critical obstacle in wind energy development. To determine the impact of the wind turbine noise and to guide the design and siting of wind turbines to minimize the disturbances on the local community, better understanding of the noise generation mechanisms as well as more accurate noise prediction techniques are necessary. Computational fluid dynamics (CFD) modeling of the National Renewable Energy Laboratory (NREL) Phase VI wind turbine at different wind speeds and tip pitch angles have been performed using ANSYS Fluent. The computational domain extends about 3 times of the wind turbine blade radius in the upstream direction, and 6 times the blade radius in the downstream and transverse directions. The shear-stress transport (SST) k-omega turbulence model is used. Second-order upwind schemes are used for the momentum and turbulence equations. The predicted pressure coefficients and power are in good agreement with the experimental data. The effects of wind speed and tip pitch angle on noise generation have also been investigated using the broadband noise source model. The Ffowcs-Williams Hawkings equation is also currently being used to obtain the far-field noise.

Renewable energies are becoming increasingly favorite for grid connected and standalone applications. With recent concerns over climate change and global warming, the US department of Energy has implemented the use of alternative forms of energy with a target of 30 % energy production using renewable energy by 2025. However, there are certain disadvantages associated with the use of alternative forms such as intermittent energy generation, and high initial investment. This makes renewable energy less reliable leading to reluctance in adoption of these new technologies amongst consumers. In this work, a high-speed scalable epicyclic gear train design is developed and studied analytically and numerically. An earlier developed Wind Tower Technology (WTT) is used as the case study for the gear train input parameters. Epicyclic gears are known to have advantages over parallel shaft drives in terms of weight, number of components, size, and power loss. These make epicyclic gear train a suitable choice for the WTT and similar concepts where an increase in the output shaft power in areas with low annual mean wind speed is required. The gear train configuration is designed based on the desired output speed and torque values, taking into consideration, the materials and the ease and novelty of machining and manufacturing. This work provides the preliminary analysis and results of developing this gearbox system for the WTT.

Renewable energy technologies are a growing subject of concern these days. Wind energy is one among the renewable energy sources which has been implemented in a large scale for energy production. A large amount of capital has been invested in this field to harness energy and power homes. Wind energy from highways is usually unused and can provide a considerable amount of wind energy to drive a turbine due to high vehicle traffic and the speed of the vehicles. Extensive research on wind patterns is required to determine the average velocity of the wind created by oncoming vehicles. The objective of this work is to design and analyze a horizontal axis wind turbine to capture wind energy from moving vehicles on the highway. A computational fluid dynamics approach is used to solve this problem. The major innovation in this paper is that wind energy is being harvested in a very unique manner and also turbine power calculations have been done to quantify the amount of energy being harvested. Although a few of the literatures have discussed similar ideas power quantification has never been done. Also the entire mechanism has been simulated in MATLAB to find out the number of cars required to charge a battery which is very unique to this paper. Power calculations have been done for the turbine and validated against theoretical calculations which were done using the concept of velocity triangles. The idea is to have a separate mounting for cars and heavy vehicles which can be realized by having separate lanes on highways. The analysis will be done for vehicles moving in a range of speeds on the highway. The wind turbines will be placed on overhead shafts (the height of which is be determined suitably) thereby capturing the wind generated as a result of pressure difference. The mounts can also be used as signboards for vehicles moving on the highway and hence serve a dual purpose. In addition, extensive structural and fatigue analysis will be done for the turbines and the mounting structures in order to determine a suitable material for the turbine as well as the mounts to withstand the forces generated. Using all of the collected energy, existing amenities such as street lights on the medians can be powered by these wind turbines. Thus the main objective of this work is to complement the conventional electrical energy used for powering amenities along highways by a renewable source of energy (wind power) thereby leading to the concept of sustainable highways.

This paper describes the feasibility analyses of an innovative, extensible ‘smart’ blade technology aims to significantly improve the wind turbine energy production. This innovative ‘smart’ blade will be extended at low wind speed to harvest more wind energy. It will be retracted to its original shape above rated wind speed, to protect the blade from possible damages under high wind speed. The extended blade, however, will inevitably increase the fatigue damage of the wind turbine blade of which fatigue demand, which often controls the design requirement of wind turbine blade. A rain-flow counting method is used for calculating stress range cycles during turbine blade operation. The analyzes model in the research is built based on a 100 kW utility-scale wind turbine installed on the campus of Case Western Reserve University with a data acquisition system installed on the wind turbine tower to monitor the operation data continuously over the years. In this analyses, the data set consists of four years’ wind speed data at 10-minutes time interval and blade rotational speed from March 2014 to February 2015 have been used. The results show that the fatigue damage of this extensible blade increased is acceptable considering its increased power output.

Kuwait is considering diversifying its energy resources and not solely depending on oil and gas. According to the Ministry of Electricity and Water (MEW), the annual increase in electricity demand is 6–8%, which is considered higher than neighboring countries (2–3%). Wind energy is one of the renewable energy resources considered by the Government to close the gap between the supply and the demand. In this work, we are exploring the feasibility of erecting a wind farm of installed capacity of 120 MW in a suitable location in Kuwait. Hourly wind data was collected from three promising locations. Abraq Al-Habari (AH), one of three areas studied, enjoys the highest average wind speed of 5.12 m/s resulting in wind power density (WPD) of 181 W/m 2 at a mast height of 10 meters. Wind Atlas Analysis and Application Program (WAsP) was used to estimate the energy production from the wind farm. The program takes into account the complexity of the terrain, the site roughness, and the obstacles and shelters effects. The results showed that the wind farm should be able to produce a net annual energy production (AEP) of 322 GWh and will cost about 260 million US$. This cost includes the installation capital cost as well as the operation expenses over the lifespan of the wind farm. The cost of energy production is estimated at 0.04 US$/kWh. The payback period considering an annual price escalation rate of 1% and a discount rate of 2.25% over the lifespan of the farm is predicted to be around ten years.

Applied Energy Systems is an elective class in Thermal-Fluids area. The course focuses on energy and fluids engineering by covering topics such as current and developing energy sources and their impact on the environment. One of the outcomes of this class is to identify and compare energy resources such as solar, wind, ocean, geothermal energy, and hydropower by covering their working principle, system components, cost analysis, benefits and drawbacks. During the semester, several small scale projects were introduced to students. These projects included a debate session on wind energy, a feasibility study on wind energy, research on a Tesla turbine, and testing of a hydro turbine. This study provides the description of each project and shows examples of student work, survey results and the assessment of the work.

This paper deals with the study of a land-yacht, that is a ground vehicle propelled by wind energy. There is a large interest in exploring alternative source of energy for propulsion and wind energy could be a feasible solution being totally green, available and free. The idea envisaged by a land-yacht is that of using one or several flexible or rigid vertical wing-sails to produce a thrust-force, which can eventually generate a higher travel velocity than its prevailing wind. A model of a three-wheel land-yacht is presented capturing the main dynamic and aerodynamic aspects of the system behaviour. Simulations are included showing how environment conditions, i.e. wind intensity and direction, influence the vehicle response and performance. In view of a robotic embodiment of the vehicle, a controller of the sail trim angle and front wheel steer angle is also discussed for autonomous navigation.

The demand for wind energy as a renewable source is rising substantially. A growing interest exists in utilizing potential energy conversion applications in areas with less powerful and less consistent wind conditions. In these areas, vertical-axis wind turbines (VAWTs) possess several advantages over the conventional horizontal-axis type. Savonius turbines are drag-based rotors which operate due to a pressure difference between the advancing and retreating blades. These turbines are simpler in design, less expensive to install, independent of wind direction, and more efficient at low wind speeds. In the present study, rotors were designed with semi-circle blades consisting of a helical shape with twist angle of 90 degrees. Helical designs spread the torque applied to the rotor over a complete revolution with the purpose of increasing efficiency. Three models were analyzed with different number of blades including 2, 3, and 4 blade models. Models for testing were designed using the CAD software SolidWorks. The blades were then 3D printed with PLA plastic. A consistent swept area was maintained for each model, and only blade number was varied. Subsonic, open-type wind tunnel testing was used for measuring RPM and reactional torque over a range of wind speeds. For the numerical approach, ANSYS Fluent simulations were used for analyzing aerodynamic performance by utilizing moving reference frame and sliding mesh model techniques. Due to the helical twist, the cross-section of the blades varied in the Y-direction. Because of this, a 3-dimensional and transient method was used for accurately solving torque and power coefficients. It has been found that the highest average power coefficient observed in the study is achieved by the Helical2 model (2-bladed helical design VAWT model), both numerically and experimentally.

Global attempts to increase generation of clean and reproducible natural energy have greatly contributed to the progress of solar, wind, biomass, and geothermal energy generation. To meet the goal set by the Renewable Portfolio Standards (RPS) in the United States, it is advisable for several of the coastal states to tap into the least explored resource: ocean-wave energy. There are many advantages to ocean-wave energy generation. First, the energy per unit area is 20 to 30 times larger compared with solar and five to ten times larger when compared to wind energy. Second, waves are more easily predicted than wind. Currently, there are several challenges with capturing ocean energy: With respect to the environment, noise pollution and effects on marine life need to be taken into consideration; with respect to design, ocean-wave power generators need to withstand large waves due to hurricanes and be designed to lessen visual pollution. There are various methods and devices used to capture ocean wave energy. Point absorbers, such as PowerBuoy , can harness vertical or heaving motion into electricity while attenuators like Pelamis use the induced movement of its joints from the incoming waves. Unfortunately, many have few parameters that can be varied to optimize power generation and or suffer from the various challenges mentioned above. The gyroscopic ocean wave energy converter harnesses the rocking or pitching motion induced by the ocean waves and converts it into rotary motion that is then fed to a generator. Furthermore, it is a fully enclosed floating device that has several parameters that can be varied to optimize power output. Previous work has demonstrated the viability of such a device, but the theoretical modeling of these converters is still in its infancy compared to that of other ocean wave energy converters. The objective of the research presented is to fully understand the mechanisms of power generation in the gyroscopic ocean wave energy converter. Using the moving frame method, a mathematical model of the device is developed. The nonlinear equations of motion are derived through the use of this novel method and then solved numerically. The results are then used to optimize the system and identify key parameters and their effect on the output power generated. Additionally, the resulting equations serve as a tool for identifying an appropriate control strategy for the system. Finally, a scale model of a gyroscopic ocean wave energy converter is developed to validate the equations of motion that have been derived.

3D wind field construction is important in many aspects, such as wind energy assessment, wind turbine siting and weather forecasting. The development of Computational Fluid Dynamics (CFD) 3D wind flow over complex terrain and boundary conditions in simulation has been studied intensively over past thirty years. However, the topographical effects has seldom been considered in the 3-D wind field construction in suburban environment. In this paper, 3-D wind field is constructed with consideration of terrain effects. 3-D terrain flowing mesh is built from digital elevation data (DEM) by in house codes. The Reynolds-averaged Navier-Stokes equations are solved by the standard k-ε turbulence model with Ansys Fluent © . The integration between the topographical effects and 3D wind field in suburban environment is investigated. Simulation results of 3-D wind field, wind velocity distributions, turbulence intensity distributions, wind power density distributions and wind profiles are obtained around Purdue University Calumet (PUC) campus. Additionally, the surround building effect and topographical effect are discussed. The simulation results are validated against measurements data.