Wind turbines are used to harvest wind energy, which can be used for generation of electricity for small-scale domestic applications and wind power plants. In this post, we will learn about the various types of wind turbines available at any Manitoulin Island wind turbine company.
Horizontal Axis Wind Turbines
HAWT is the most widely used wind turbine. The design of these turbines implements the same idea as windmills. The rotor blades are connected to the shaft, which is connected to a generator, and rotate as the wind strikes them, thus producing electrical energy. The propellers are mounted on top of a mast or tower.
The Manitoulin Island wind turbines company will align these wind turbines with the wind direction and require a sensor that detects the direction of the wind. It also requires some yawing mechanism to turn the device properly aligned against the wind. Facing the wind helps it to more effectively distribute force on the rotors and also prevent structural damage to the turbine due to improper loading on the turbine structure.
The structure of HAWT needs to be strong enough to support the weight of the gearbox, rotor blades, generator and other such components of the turbine. The base of the mast should be able to withstand strong winds that are blown where the turbine is installed. Horizontal-axis wind turbines are the most common types due to their efficiency and higher power generation capacity for the same footprint. Hence, many power plants with a number of wind turbines generating power use these types of wind turbines. HAWT are further divided into two types:
- Up-wind turbines: these turbines face the wind. When the wind reaches the rotors before the mast, they do not suffer from wind shade behind the tower. This means that a more efficient operation will occur, and it will be less susceptible to wear and tear of the rotors. However, the necessity for a yawing mechanism can add to the structure’s weight.
Up-wind type turbines do not have flexible rotors, so they do not bend and collide with the mast when the wind speed is high. Also, the rotor is placed at some distance from the tower to further reduce the risk of such incidents. However, this adds to the manufacturing difficulties of up-wind turbines. Also, the inflexibility of the rotor blades requires them to have heavy materials for blade construction, thus adding to manufacturing difficulty.
- Down-wind Turbines: these are less common, and their designs look the same except for the location of the rotor. It is placed downstream of the tower, and the wind strikes the cast before it reaches the blades. This allows for more flexibility of the rotor blades because lighter materials can be used. Therefore, such a design can serve two purposes: better structural dynamics of the tower and lower structural weight by taking some of the load off the tower to the blades during their bending.
These turbines do not theoretically require any yawing mechanism as long as the rotor and the casing are designed to follow the wind direction passively. Since the rotor in the wind turbines is located downstream of the mast, they may suffer from wind shade, which includes fluctuations in the amount of power generated and more fatigue of down-wind types of wind turbines.
Vertical Axis Wind Turbines
VAWT has rotors that rotate a vertical shaft. This design allows for less sensitivity regarding wind direction, thus making them a perfect choice for places where the wind direction frequently changes. The blades will move and rotate the shaft to produce power no matter what direction the wind blows.
The generators in vertical axis wind turbines are located near the ground because taking it to a height would not be plausible due to the rotors’ design and height. This makes their maintenance easier compared to HAWTs since all the components are installed at some height. However, VAWTs are less efficient than HAWTs as a significant amount of air drags on the rotor. They also have less power output. The various types of vertical-axis wind turbines include:
- Savonius turbines: these turbines run by drag force. These turbines rotate no matter the direction the wind blows. They are very good at working with low-speed winds, work well in turbulent winds, and are easy to manufacture and maintain.
- Darrieus turbines: these turbines work on the idea of lift production of airfoils. They are mainly used in wind turbines with C-shaped, curved blades that go from the top of the tower to the bottom.
- Giromill turbines consist of straight vertical blades instead of curved ones and may not have a steady rotation speed.
- Cycloturbines: the airfoil blades of these turbines are of the variable-pitch type. So when the wind is not fast enough, the blades are pitched against the wind.
Bottom Line
Residential wind turbines can be profitable and practical power sources for homeowners. Though it may not provide all the electricity you need, it could lower your electricity bills significantly. However, you need to make sure that you choose the right turbine for your location.