Wind Energy

Wind Energy is generated by harnessing the kinetic energy of the wind.

Wind Energy has had been in use for centuries for several other purposes such as sailing, irrigation and for grinding grain.

More than 80% of the global Wind Energy capacity is installed in 5 countries (Germany, USA, Denmark, Spain and India) with India at the 5th position.

Wind power is the fastest growing source of renewable energy globally with an established capacity in excess of 14,000 MW, if harnessed efficiently it can help generate 10 times the energy that is being used at present.

Wind turbines

Wind turbines work by transforming the Wind Energy into mechanical power that can be used for conversion to electricity or for other mechanical purposes like grinding.

Parts of Wind Turbine

Parts of Wind Turbine

Anemometer: Measures the wind speed and transmits wind speed data to the controller.

Blades: Most turbines have either two or three blades. Wind blowing over the blades causes the blades to rotate.

Brake: A disc brake, which can be applied mechanically or electrically to stop the rotor in emergencies.

Controller: The controller starts up the machine at wind speeds of about 8 to 16 miles per hour (mph) and shuts off the machine at about 55 mph. Turbines do not operate at wind speeds above about 55 mph because they might be damaged by the high winds.

Parts of Wind Turbine Gear box: Gears connect the low-speed shaft

to the high-speed shaft and increase the rotational speeds from about 30 to 60 rotations per minute (rpm) to about 1000 to 1800 rpm, the rotational speed required by generators to produce electricity. The gear box is a costly (and heavy) part of the wind turbine .

Generator: Usually generator that produces 60-cycle AC electricity.

High-speed shaft: Drives the generator. Low-speed shaft: The rotor turns the low-speed

shaft at about 30 to 60 rotations per minute.

Parts of Wind Turbine Nacelle: The nacelle sits a top the tower and contains the gear

box, low- and high-speed shafts, generator, controller, and brake.

Rotor: The blades and the hub together are called the rotor. Tower: Towers are made from tubular steel or concrete.

Because wind speed increases with height, taller towers enable turbines to capture more energy and generate more electricity.

Wind vane: Measures wind direction and communicates with the yaw drive to orient the turbine properly with respect to the wind.

Yaw drive: Upwind turbines face into the wind; the yaw drive is used to keep the rotor facing into the wind as the wind direction changes. Downwind turbines don't require a yaw drive, the wind blows the rotor downwind.

Yaw motor: Powers the yaw drive.

Working of Wind Turbine

Blades of wind turbine are attached to a rotor assembly. When the atmospheric wind blows over the fan blades

they start rotating, they turn and spin the rotor. Due to this the shaft also starts rotating. The speed of rotation of the shaft is very slow, to

increase the output speed the shaft is connected to the gear box.

The high speed output shaft from the gearbox is connected to the generator and it rotates inside the generator.

It is here that the electricity is produced.

Wind Energy Generation

Wind Energy Advantages Renewable - so no matter how much is used today,

there will still be the same supply in the future Wind energy is a Cost free. Eco-friendly ,Clean and Non-Polluting Resource-

Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases.

Wind Energy is cheaper, it doesn’t take millions of years to form, which is the case with fossil fuels.

A smaller area is required to setup wind turbines, compared to the area required for setting up power stations.

The land used for generating wind power can be used for cattle grazing and agricultural purposes.

Energy that can be accessed by remote areas where it is expensive and difficult to run electrical lines.

Wind Energy Disadvantages

Supply- it is intermittent and does not always blow when electricity is needed and Wind cannot be stored

Not all winds can be harnessed to meet the timing of electricity demands.

Transport - Remote locations far from areas of electric power demand (such as cities).

Cost -Technology requires a higher initial investment . Some concern over the noise produced by the rotor blades,

aesthetic (visual) impacts, and birds and bats having been killed (avian/bat mortality) by flying into the rotors

Wind resource development may compete with other uses for the land, and those alternative uses may be more highly valued than electricity generation.