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Wind Power
Published in Robert Ehrlich, Harold A. Geller, John R. Cressman, Renewable Energy, 2023
Robert Ehrlich, Harold A. Geller, John R. Cressman
Small wind refers to wind turbines for homeowners, ranchers, or small businesses, and they can have rated powers as low as 50 W or as high as 50 kW. For much of the early years of the twentieth century, small wind turbines provided the only source of electricity in rural areas of the United States. Today, they are purchased for various reasons including battery charging and reducing one’s dependence on the grid or one’s carbon footprint. The economic feasibility and installation of a small wind turbine can be far more problematic than solar panels, in view of the great variability in wind potential with location, even on a particular property, where one must pay careful attention to the terrain, vegetation, height, and placement of obstacles (Figure 7.25). Densely populated areas, in particular, represent among the poorest locations. For some locations, the average wind speed will be far short of what is needed to generate the rated power more than a very small percentage of the time. Nothing can be more vexing to the naive buyer than to purchase a turbine rated at 3 kW only to find that it generates that power 1% of the time! Moreover, until fairly recently, different manufacturers could rate their turbines at different wind speeds, making a direct comparison very difficult.
Wind Power
Published in Robert Ehrlich, Harold A. Geller, Renewable Energy, 2017
Robert Ehrlich, Harold A. Geller
Small wind refers to wind turbines for homeowners, ranchers, or small businesses, and they can have rated powers as low as 50 W or as high as 50 kW. For much of the early years of the twentieth century, small wind turbines provided the only source of electricity in rural areas of the United States. Today, they are purchased for various reasons including battery charging and reducing one’s dependence on the grid or one’s carbon footprint. The economic feasibility and installation of a small wind turbine can be far more problematic than solar panels, in view of the great variability in wind potential with location, even on a particular property, where one must pay careful attention to the terrain, vegetation, height, and placement of obstacles (Figure 7.25). Densely populated areas, in particular, represent among the poorest locations. For some locations, the average wind speed will be far short of what is needed to generate the rated power more than a very small percentage of the time. Nothing can be more vexing to the naive buyer than to purchase a turbine rated at 3 kW only to find that it generates that power 1% of the time! Moreover, until fairly recently, different manufacturers could rate their turbines at different wind speeds, making a direct comparison very difficult.
Modular Wind Energy Systems
Published in Yatish T. Shah, Modular Systems for Energy and Fuel Recovery and Conversion, 2019
A small wind turbine is a wind turbine used for microgeneration, as opposed to large commercial wind turbines, such as those found in wind farms, with greater individual power output. The Canadian Wind Energy Association defines “small wind” as ranging from less than 1,000 W (1 kW) turbines up to 300 kW turbines [2]. The smaller turbines may be as small as a 50 W auxiliary power generator for a boat, caravan, or miniature refrigeration unit. The IEC 61400-2:2006 Standard defines small wind turbines as wind turbines with a rotor swept area smaller than 200 m2, generating at a voltage below 1,000 Va.c. or 1,500 Vd.c.
Experimental study of a winglet added small wind turbine with a flanged diffuser for domestic applications
Published in International Journal of Ambient Energy, 2022
M. Udhayakumar, P. Saravanan, K.M. Parammasivam
It's a small attachment that has the same cross section of the blade at the tip of the blade. The objective of mounting the winglet to the blades of wind turbine is to reduce the total blade drag and increase the turbine's aerodynamic efficiency. If the additional drag of the winglet is less than the reduction of the induced drag on the remaining blade length, the total drag is obtained. The design of winglet optimises drag reduction, maximises power generation and minimises thrust increase (Johansen and Sorensen 2006). The pressure difference in the operating wind turbine blade is the inward span wise flow on the suction side and the outward span wise flow on the pressure side near the tip. There is a vorticity at the trailing edge, which is the origin of the induced drag. A winglet is a device that reduces the span wise flow, diffuses and moves the tip vortex away from the rotor plane reducing the induced drag on the blade (Dreese 2000). A range of parameters are involved in the winglet design, such as winglet height, angle of sweep, angle of tip, radius of curvature, angle of toe and twist angle as shown in Figure 1. In the aerodynamics perspective, it is proposed to study the effect of winglet on this small wind turbine rotor efficiency. Teak wood blade model was fabricated with a scale of 1:120 and used as a standard for GFRP (Glass Fiber Reinforced Polymer) blades (Figures 2 and 3) (Martin and Hansen 2008).
Influence of Reynolds number on the performance of small horizontal axis wind turbine with fixed speed operation
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
The present work incorporates performance prediction of the considered small wind turbine rotor blade with fixed speed operation, and utilizing aerodynamic characteristics of the airfoil section at various range of Re. For a comprehensive understanding of the influence of various approximated fixed Re considerations for aerodynamic characteristics, on the performance of rotor blade with change in wind speed, the variation of operating parameters such as, axial and tangential induction factors, angle of attack, flow angle, lift to drag ratio, Re and power coefficient are studied. The fixed rotor speed corresponds to design tip speed ratio of 6 and wind speed of 6 m/s. The blade performance is evaluated for range of wind speeds i.e., 6, 8, 10, and 12 m/s and since the rotor speed is fixed, with change in the wind speed, the operating tip speed ratio also changes to 6, 4.5, 3.6, and 3.0, respectively.
Energy sustainability analysis based on SDGs for developing countries
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
A. Armin Razmjoo, Andreas Sumper, Afshin Davarpanah
The use of renewable energy today is one of the most appropriate ways of generating electricity (Šúri et al. 2007) and achieve to energy sustainability (Alazraque-Cherni 2008; Neves and Leal 2010). Various countries with long-term planning and investment in renewable energy are trying to provide a significant portion of their future energy needs in the future (Dincer 2011). Among different kind of renewable energies, the role of wind and solar energy is significant for electrical production (Zhou et al. 2010). Today importance of smart grid system is vital for energy supply and a safe future. Figure 2 shows the evolutionary feature of the smart grid that can create bidirectional flows of energy and communication. As can see this system combines a small wind turbine and photovoltaic solar panels. In this system in order to supply energy to an inverter is used of the extracted energy.