Everything That You Need to Know About Wind Energy. Wind is a type of renewable energy generated by three simultaneous events:
- The sun heats the atmosphere unevenly.
- Surface irregularities of the Earth
- The earth’s rotation.
Wind is used to generate electricity by using the kinetic energy provided by moving air. Wind turbines are used to convert this motion into electrical energy. A wind turbine generates electricity by turning the wind’s force into a torque (turning force) acting on the rotor blades.
The quantity of energy transferred to the rotor by the wind is determined by the density of air, the rotors area, and the wind velocity. Individual wind turbines may produce up to 100 kilowatts of power, enough to power an apartment. Small turbines are also used in places like water pumping stations. Turbines may reach a height of 80 meters and have 40-meter-long rotor blades. These turbines have a capacity of 1.8 megawatts. Even bigger wind turbines mounted on 240-meter-tall towers contain rotor blades that are more than 162 meters long. These massive turbines can produce 4.8 to 9.5 megawatts of power.
Wind energy hits lowest cost point among both non-renewable and renewable new electricity generation options
1. Foundation The substructure connects the tower to the base and handles the static and dynamic loads of the turbine. For improved stability, a foundation composed of steel mesh and concrete is typically utilized to anchor the turbine to the ground.
Most current turbines have a circular tubular steel tower with a diameter of 3-4 m, depending on the dimensions of the turbine as well as its location. A turbine tower should have the same height as the diameter of the circle formed by its rotating blades. The height of a tower is critical for turbines since wind speed rises with height. As a result, most turbines are designed to reach heights of 50 to 150 meters, where the wind is strong but the load is minimal owing to turbulence.
The shaft is the rotational part of a turbine; it is made up of (usually) three blades and the hub, which acts as the centre element to which the blades are joined. A turbine does not need to have three blades; it can have two, four, or any number of blades. However, the three-blade rotor offers the highest energy efficiency and other benefits.
The blades are hollow and built of a composite to be lightweight and strong. The current tendency is for them to be larger (for greater power), lighter, and stronger. To be aerodynamic, the blades have the shape of an air foil (similar to aviation wings). They are also not flat and they have a twist around their root and tip. The blades can rotate up to 90° about their axes. This motion is called blade pitch.
The hub’s role is to keep the blades and allow them to spin in relation to the rest of the turbine body.
The nacelle is the wind turbine’s ‘head,’ and it is positioned on pinnacle of the support tower. The rotor blade assembly is linked to the nacelle’s front. A conventional 2MW onshore wind turbine assembly’s nacelle weighs roughly 72 tonnes. Housed inside the nacelle are five major components
a. Gearbox assembly
b. Aerodynamic braking system
c. Mechanical braking system
d. Turbine generator
e. Electrical power transmission systems
The gearbox unit receives the rotating input shaft from the center of the rotor blade assembly and speeds it up to a high sufficient speed to drive the turbine generator at its maximum generating speed. The generator is then rotated directly by the high-speed output shaft from the gearbox.
Modern wind turbines employ two types of braking systems: aerodynamic braking and mechanical (friction) braking. Aerodynamic braking, also known as “rotor feathering,” is performed by twisting the rotor blades such that they expose a narrower cross section to the approaching wind; this means they ‘capture’ less of the wind and hence revolve slower.
The gearbox unit incorporates the mechanical braking mechanism. Mechanical braking is just another name for friction braking, which is seen in automotive brakes. A rotating disc is installed on the gearbox’s input shaft, and brake pads are clamped onto the disc using a hydraulic actuator, gradually slowing the blade assembly to a full stop. Most wind speeds do not need the use of mechanical braking devices in normal operation; the rotation speed of the blades is regulated only by aerodynamic braking. Mechanical brakes are only used if the turbine must be totally stopped, such as to allow employees to do maintenance or to stop the turbine from generating if there is too much power on the electrical grid.
The turbine generator is the component that converts the rotational energy in the gearbox’s high-speed output shaft into an electrical current. The electromagnetic induction electrical principle states that as a magnet moves through a coil of wire, an electric current is formed (or “induced”) in the wire.
e. Electrical Power Transmission Systems
The generator’s electrical current is not yet ready to be sent to the national electricity grid, therefore it is first fed into a series of electrical circuits that change the voltage to the proper level so that it can relate to the system with maximum energy efficiency. This electrical power is then supplied back down into the support tower through wires to be connected to the grid. From there, that electricity is supplied for use by homes and businesses.