Wind energy makes use of turbines to produce electricity without producing waste or polluting the environment. With a design based on the traditional windmill, energy-producing wind turbines provide power when the wind turns the blades which, in turn, spin a shaft connected to a generator. Typically, turbines are erected in large numbers, close by and in areas known for consistently high winds to create what are known as wind farms. In large numbers, wind turbines can produce significant energy, but they lack the reliability of other energy sources.
Normally there are two designs of wind turbines, horizontal-axis and vertical-axis. Vertical-axis wind turbines (VAWTs) are pretty rare. The only one currently in commercial production is the Darrieus turbine, which looks kind of like an egg beater.
In a VAWT, the shaft is mounted on a vertical axis, perpendicular to the ground. VAWTs are always aligned with the wind, unlike their horizontal-axis counterparts, so there's no adjustment necessary when the wind direction changes; but a VAWT can't start moving all by itself -- it needs a boost from its electrical system to get started. Instead of a tower, it typically uses guy wires for support, so the rotor elevation is lower. Lower elevation means slower wind due to ground interference, so VAWTs are generally less efficient than HAWTs. On the upside, all equipment is at ground level for easy installation and servicing; but that means a larger footprint for the turbine, which is a big negative in farming areas.
VAWTs may be used for small-scale turbines and for pumping water in rural areas, but all commercially produced, utility-scale wind turbines are horizontal-axis wind turbines (HAWTs).
As implied by the name, the HAWT shaft is mounted horizontally, parallel to the ground. HAWTs need to constantly align themselves with the wind using a yaw-adjustment mechanism. The yaw system typically consists of electric motors and gearboxes that move the entire rotor left or right in small increments. The turbine's electronic controller reads the position of a wind vane device (either mechanical or electronic) and adjusts the position of the rotor to capture the most wind energy available. HAWTs use a tower to lift the turbine components to an optimum elevation for wind speed (and so the blades can clear the ground) and take up very little ground space since almost all of the components are up to 260 feet (80 meters) in the air.
Large HAWT components:
rotor blades - capture wind's energy and convert it to rotational energy of shaft
shaft - transfers rotational energy into generator
nacelle - casing that holds the gearbox (increases speed of shaft between rotor hub and generator), generator {uses rotational energy of shaft to generate electricity using electromagnetism), electronic control unit (monitors system, shuts down turbine in case of malfunction and controls yaw mechanism), yaw controller (moves rotor to align with direction of wind) and brakes (stop rotation of shaft in case of power overload or system failure).
tower - supports rotor and nacelle and lifts entire setup to higher elevation where blades can safely clear the ground
electrical equipment - carries electricity from generator down through tower and controls many safety elements of turbine
From start to finish, the process of generating electricity from wind -- and delivering that electricity to people who need it -- looks something like this:
A wind turbine is a series of blades connected to a central rotor and angled to move when struck by sufficiently strong winds. As the blades move, they generate energy that can be used in a variety of applications from production of electricity to ventilation and atmospheric measurements. The blades of a turbine either radiate out from the center in a spoke-like pattern or wrap around the rotating portion of the turbine, depending on their use.
When the wind blows across turbines on the roofs of homes and buildings, the turbines turn and create a vacuuming effect. This process moves air from inside the ventilation system to the outside, drawing fresh air into the building from other parts of the home, such as open windows. Rooftop turbines also have the added benefit of cooling the interior of a building, as warmer air from inside rises and contributes to the turbine's turning, drawing cooler air into the structure from outside.
Turbines are an integral component in anemometers, which are devices used to measure wind speed. Measuring wind speed is a necessity for airports and heliports so that the safety of launching aircraft can be determined. It is also done by prospectors to determine the viability of a location for a wind farm.
Wind is a clean, renewable energy source caused by the uneven heating of the Earth's surface. It can be used to generate electricity through wind turbines. Wind turbines collect kinetic energy from the wind through blades. The blades of the wind turbine are connected to a drive shaft and a generator. When the wind blows over the blades, it causes them to turn the drive shaft and generate electricity.
Features of the typical wind turbine include blades, brake controller, anemometer, gear box, generator, high-speed shaft, low-speed shaft, nacelle and wind vane. The blades cause the lift and rotation of the generator. The brake controller starts and stops the turbine. The anemometer measures the wind speed and transmits the data to the brake controller. The gear box is made up of gears which connect the low-speed shaft to the high-speed shaft. The high-speed shaft drives the generator. The nacelle houses the gear box, shafts, generator, controller and brake. The wind vane measures the wind direction.
