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As the interest in renewable energy increases and the number of federal and state incentives to support renewable energy has also grown in recent years, it seems worthwhile to explore the economics of using small wind energy systems to offset electricity costs on farms. The purpose of this paper is to explore the economics of small wind turbine installations on a dairy in Michigan through case study analysis.

An Excel‐based capital budgeting model is developed that contains two sub‐modules: one that estimates the value of the wind energy based on the measured wind resource, and an investment module that includes factors such as investment cost, financing parameters, sales of electricity; grants and tax credits and tax information. Cases using 20 and 50 kW turbine systems are analyzed.

The results of the case studies show that in a favorable wind resource, the federal tax and United States Department of Agriculture incentives as well as state policies such as net metering can make wind turbines a good investment with an internal rate of return of 12.5 percent in this example. However, if the wind resource is not sufficient, even favorable renewable energy policies will not offset the lost value of the power generation, and thus a wind turbine will be a poor investment decision. Farm businesses should carefully consider all factors before investing in a wind turbine.

This paper is the first in recent years to combine capital budgeting analysis, wind resource data and the implications of federal and state policies to determine if small wind turbines are a sound investment decision for farm businesses.

Sustainable energy has been on the political agenda in Denmark for decades. This chapter will highlight how wind turbine production quite unforeseen became a great success in Denmark before the turn of the Millennium. An integrative public leadership approach using a mix of supportive institutional designs and instruments, combined with an unexpected bottom-up pressure for alternatives to nuclear power, promoted ways for wind turbine innovation and production in the 1970s. After the turn of the Millennium, being a huge financial success creating many new jobs and export has it developed into a cluster based on huge investments and professionalised developers. The comprehensive transition of wind turbine production in Denmark, from small scale to large scale, has however provided a counterproductive decrease in community commitment for local renewable energy production.

Denmark is known internationally as a climate frontrunner and not only due to wind turbine production and planning. The status is obtained by polycentric governance applied in cooperative-owned energy systems. The Danish response to climate change is a concerted effort of a plethora of public and private actors, providing a crucial momentum and robustness in climate politics not at least generated from a genuine civic society involvement. ‘The Danish Energy Model’; a withhold strategic effort to combine ambitious renewable energy goals, energy efficiency targets and political support of technical and industrial development has for four decades, succeeded in providing high levels of cheap energy supply, while partly reducing fossil fuel dependency at the same time.

A solution to increase the energy production rate of the wind turbine is proposed by forcing more air to move through the turbine working section. This can be achieved by equipping the rotor with a diffusing channel ended with a brim (diffuser augmented wind turbine – DAWT). The purpose of this paper is to design an experimental stand and perform the measurements of velocity vector fields through the diffuser and power characteristic of the wind turbine.

The experiments were carried out in a small subsonic wind tunnel at the Institute of Turbomachinery, Lodz University of Technology. An experimental stand design process as well as measurement results are presented. Model size sensitivity study was performed at the beginning. The experimental campaign consisted of velocity measurements by means of particle image velocimetry (PIV) and pneumatic pitot probe as well as torque and rotational velocity measurements.

Characteristics (power coefficient vs tip speed ratio) of the bare and shrouded wind turbine were obtained. The results show an increase in the wind turbine power up to 70-75 per cent by shrouding the rotor with a diffuser. The mechanisms responsible for such a power increase were well explained by the PIV and pneumatic measurement results revealing the nature of the flow through the diffuser.

Experimental stand for wind turbine rotor testing is of a preliminary character. Most optimal methodology for obtaining power characteristic should be determined now. Presented results can serve as good input for choice of stable and reliable control system of wind turbine operational parameters.

A 3 kW DAWT is being developed at the Institute of Turbomachinery, Lodz University of Technology. Aim of the study is to design a compact and smart wind turbine optimised for low wind speed conditions. Developed wind turbine has a potential to be used as an effective element within a net of distributed generation, e.g. for domestic use.

Research carried out is the continuation of theoretical study began in 1970s. It was also inspired by practical solutions proposed by Japanese researchers few years ago. Presented paper is the summary of work devoted to optimisation of the DAWT for wind conditions in the region. Original solution has been applied, e.g. for experimental stand design (3D printing application).

The purpose of this paper is to thoroughly investigate the aerodynamic effects of blade pitch angle on small scaled horizontal axis wind turbines (HAWTs) using computational fluid dynamics (CFD) method to find out the sophisticated effects on the flow phenomena and power performance.

A small HAWT is used as a reference to validate the model and examine the aerodynamic effects. The blade pitch angle was varied between +2 and −6 degrees, angles which are critical for the reference wind turbine in terms of performance, and the CFD simulations were performed at different tip speed ratio values, λ = 2, 3, 4, 5, 6, 7, 9 and 10.5 to cover the effects in various conditions. Results are examined in two different aspects, namely, general performance and the flow physics.

The power performance varies significantly according to the tip speed ratio; the power coefficient increases up to a certain pitch angle at the design tip speed ratio (λ = 6); however, between λ = 2 and 4, the more the blade is pitched downwards, the larger is the power coefficient, the smaller is the thrust coefficient. Similarly, for tip speed ratios higher than λ = 8, the positive effect of the low pitch angles on the power coefficient at λ = 6 reverses. The flow separation location moves close to the leading edge at low tip speed ratios when the blade is pitched upwards and the also tip vortices become more intense. In conclusion, the pitch control can significantly contribute to the performance of small HAWTs depending on different conditions.

In the literature, only very little attention has been paid to the aerodynamic effects of pitch angle on HAWTs, and no such study is available about the effects on small HAWTs. The change of blade pitch angle was maintained at only one degree each time to capture even the smallest aerodynamic effects, and the results are presented in terms of the power performance and flow physics.

The purpose of this paper is to find out a new potential site for energy generation to maximize the energy generation via installing utility wind turbines.

In this paper, Weibull two-parameter methodologies are used to determine the effectiveness of the wind speed at three different heights including 80, 60 and 30 m. Standard deviation and wind power density (WPD) are also calculated for the site. After analyzing the wind resource, the wind turbine selection is materialized to maximize the energy production, considering the best configuration of the wind turbines that is suitable for the site. In the end, economic aspect is also calculated.

The mean Weibull dimensionless parameter k is found to be 2.91, 2.845 and 2.617, respectively. The mean Weibull scale parameter c is found to be 6.736, 6.524 and 6.087 at the heights of 80, 60 and 30 m, respectively. The mean standard deviation is found to be 2.297, 2.249 and 2.157 at the heights of 80, 60 and 30 m at the heights of 80, 60 and 30 m, respectively. Wind power densities are calculated to be 265, 204 and 157.9 W/m² at the heights of 80, 60 and 30 m, respectively (highest in the month of July when the mean wind speed is 7.707 m/s and WPD is 519 W/m²). Finally, site-specific economic analysis of wind turbines is carried out, which shows $0.0230 per kWh at the height of 80 m.

The results show that the site is beneficial for the installation of small and large wind turbines.

One of the most significant challenges facing contemporary architectural and urban design is how it can become more sustainable. Energy consumption by housing is a major source of greenhouse gas emissions and a cause of depletion of non-renewable energy sources. Of particular concern is existing stock, which has the worst performance and is hardest to improve.

One means of addressing these issues that is attracting increasing interest is the integration of embedded renewable energy technologies. This paper discusses the use of wind turbines on buildings as a response to climate change legislation. It examines the potential for embedded generation in a specific built form (existing high rise housing) and places this in the context of a particular geographical location (Glasgow, Scotland) where the existing provision is highly problematic, but which also presents significant potential. It describes findings from two projects in Glasgow, a pilot installation on a city centre multi-storey block, and subsequent feasibility study for a Housing Association managed multi-storey block and identifies the problems and opportunities that may be applied in similar projects elsewhere.

Wind turbines are one of the best candidates to solve the problem of increasing energy demand in the world. The aim of this paper is to apply a multi-objective structural optimization study to a Phase II wind turbine blade produced by the National Renewable Energy Laboratory to obtain a more efficient small-scale wind turbine.

To solve this structural optimization problem, a new Non-Dominated Sorting Genetic Algorithm (NSGA-II) was performed. In the optimization study, the objective function was on minimization of mass and cost of the blade, and design parameters were composite material type and spar cap layer number. Design constraints were deformation, strain, stress, natural frequency and failure criteria. ANSYS Composite PrepPost (ACP) module was used to model the composite materials of the blade. Moreover, fluid–structure interaction (FSI) model in ANSYS was used to carry out flow and structural analysis on the blade.

As a result, a new original blade was designed using the multi-objective structural optimization study which has been adapted for aerodynamic optimization, the NSGA-II algorithm and FSI. The mass of three selected optimized blades using carbon composite decreased as much as 6.6%, 11.9% and 14.3%, respectively, while their costs increased by 23.1%, 29.9% and 38.3%. This multi-objective structural optimization-based study indicates that the composite configuration of the blade could be altered to reach the desired weight and cost for production.

ACP module is a novel and advanced composite modeling technique. This study is a novel study to present the NSGA-II algorithm, which has been adapted for aerodynamic optimization, together with the FSI. Unlike other studies, complex composite layup, fiber directions and layer orientations were defined by using the ACP module, and the composite blade analyzed both aerodynamic pressure and structural design using ACP and FSI modules together.

The aim of this paper is to analyze the wind regime at Wainiyaku, Taveuni in Fiji, estimate Annual Energy Production (AEP) using a 275 kW Vergnet wind, and determine its economic viability.

The only grid supply is in the northeast (suburban area) of the island. The main source is diesel generators, which are operated only certain hours per day. The study around Wainiyaku state was essential to determine an alternative continuous source of energy. The wind assessment on the island was based on the data provided by the Department of Energy (Fiji) and WAsP was used to reliably estimate the wind power potential on the island.

The report suggested that Wainiyaku Taveuni is a good site for wind power generation based on mean wind speed at 30 m agl. The software predicted a resource grid for mean wind speed and power density around Wainiyaku. An economic analysis for a prospective wind power generation using Vergnet 275 kW showed a reasonable promise.

The conclusion justifies that a longer period (3y) data are necessary for better accuracy. However, one‐year data are sufficient to predict annual energy production with reasonable certainty.

The paper provides an alternative solution for a continuous supply of electricity for a remote island. It shows the economics of utilizing wind power generator to provide unobstructed supply of electricity. It further explores the saving in foreign exchange for a small Island economy. The analysis of wind regime suggests that an independent power producer may consider investing in a wind farm at Wainiyaku.

This study aims to carry out numerical modeling to predict aerodynamic noise radiation from four different Savonius rotor blade profile.

Incompressible unsteady reynolds-averaged navier-stokes (URANS) approach using gamma–theta turbulence model is conducted to obtain the time accurate turbulent flow field. The Ffowcs Williams and Hawkings (FW-H) acoustic analogy formulation is used for noise predictions at optimal tip speed ratio (TSR).

The mean torque and power coefficients are compared with the experimental data and acceptable agreement is observed. The total and Mono+Dipole noise graphs are presented. A discrete tonal component at low frequencies in all graphs is attributed to the blade passing frequency at the given TSR. According to the noise prediction results, Bach type rotor has the lowest level of noise emission. The effect of TSR on the noise level from the Bach rotor is investigated. A direct relation between angular velocity and the noise emission is found.

The savonius rotor is a type of vertical axis wind turbines suited for mounting in the vicinity of residential areas. Also, wind turbines wherein operation are efficient sources of tonal and broadband noises and affect the inhabitable environment adversely. Therefore, the acoustic pollution assessment is essential for the installation of wind turbines in residential areas.

This study aims to investigate the radiated noise level of four common Savonius rotor blade profiles, namely, Bach type, Benesh type, semi-elliptic and conventional. As stated above, numbers of studies exploit the URANS method coupled with the FW-H analogy to predict the aeroacoustics behavior of wind turbines. Therefore, this approach is chosen in this research to deal with the aeroacoustics and aerodynamic calculation of the flow field around the aforementioned Savonius blade profiles. The effect of optimal TSR on the emitted noise and the contribution of thickness, loading and quadrupole sources are of interest in this study.

This paper aims to discuss the results of the performance study of wind turbine blades equipped with winglets. An investigation focusses on small wind turbines (SWTs), where the winglets are recalled as one of the most promising concepts in terms of turbine efficiency increase.

To investigate a contribution of winglets to SWT aerodynamic efficiency, a wind tunnel experiment was performed at Lodz University of Technology. In parallel, computational fluid dynamics (CFD) simulations campaign was conducted with the ANSYS CFX software to investigate appearing flow structures in greater detail.

The research indicates the potential behind the application of winglets in low Reynolds flow conditions, while the CFD study enables the identification of crucial regions influencing the flow structure in the most significant degree.

As the global effect on a whole rotor is a result of a small-scale geometrical feature, it is important to localise unveiled phenomena and the mechanisms behind their generation.

Even the slightest efficiency improvement in a distributed generation installation can promote such a solution amongst energy prosumers and increase their independence from limited natural resources.

The winglet-equipped blades of SWTs provide an opportunity to increase the device performance with relatively low cost and ease of implementation.