CHAPTER 3WIND POWER

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GTU WEIGHTAGE:- 14 MARKS

Wind Power

Where Does the Wind Come From? The wind is a by-product of solar energy.

Approximately 2% of the sun's energy reaching the earth is converted into wind energy.

The surface of the earth heats and cools unevenly, creating atmospheric pressure zones that make air flow from high- to low-pressure areas.

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

Wind Power

Equation Of Wind Power The amount of power available in the wind is determined by the equation:

w = 1/2 r A v3

w is power, r is air density, A is the rotor area, and v is the wind speed.

This equation states that the power is equal to one-half, times the air density, times the rotor area, times the cube of the wind speed. Air density varies according to elevation, temperature and weather fronts

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

Wind Turbines

Defination rotary engine in which the kinetic energy of a moving fluid is converted into mechanical energy by causing a bladed rotor to rotate”.

Wind rotates the turbine blades:-1. spins a shaft connected to a generator 2. The spinning of the shaft in the generator makes electricity

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

Wind TurbinesClassificationThere are two types of wind turbines

1. Horizontal axis wind turbine (HAWT)

2. Vertical axis wind turbine (VAWT)

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

Horizontal axis wind turbine (HAWT)Introduction This is the most common wind turbine

design.

In addition to being parallel to the ground, the axis of blade rotation is parallel to the wind flow.

Some machines are designed to operate in an upwind mode, with the blades upwind of the tower. In this case, a tail vane is usually used to keep the blades facing into the wind.

Other designs operate in a downwind mode so that the wind passes the tower before striking the blades.

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Horizontal axis wind turbine (HAWT)Types1. ACCORDING TO NUMBER OF BLADESA. MONOBLADEB. TWINE BLADEC. TRIPLE BLADE

2. ACCORDING TO POWER OUTPUTA.SMALL CAPACITY- 10-50KW; ROTOR DIA. 1-16METERSB.MEDIUM CAPACITY: 50-500KW; ROTOR DIA. 16-50METERC.LARGE CAPACITY: 500-1000KW; ROTOR DIA 50-130METER

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Horizontal axis wind turbine (HAWT)MONOBLADE TWINE BLADE TRIPLE BLADE

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Horizontal axis wind turbine (HAWT) TYPES

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3. LIFT AND DRAG TYPE HAWT

Horizontal axis wind turbine (HAWT) TYPES

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4. ACCORDING TO UPWIND AND DOWN WIND TURBINESA. TURBINE WHICH FACE WIND

STREAM ARE CALLED UP WIND TURBINE

B. B. TURBINE WHICH RECIEVES WIND FROM REAR SIDE ARE DOWN WIND TURBINE

Vertical axis wind turbine (VAWT) TypesThere are two types of VAWT

1. Savonius Wind Turbines

2. Darrieus Wind Turbines

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

Vertical axis wind turbine (VAWT) 1. Savonius Wind TurbinesThe Savonius turbine is S-

shaped if viewed from above. This drag-type VAWT turns

relatively slowly, but yields a high torque.

It is useful for grinding grain, pumping water, and many other tasks, but its slow rotational speeds make it unsuitable for generating electricity on a large-scale.

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

Vertical axis wind turbine (VAWT) Introduction to Digital System

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

1. Savonius Wind Turbines

Vertical axis wind turbine (VAWT) Introduction to Digital System The Darrieus turbine is the

most famous vertical axis wind turbine.

It is characterized by its C-shaped rotor blades which give it its eggbeater appearance.

It is normally built with two or three blades.

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

1. Darrieus Wind Turbines

Vertical axis wind turbine (VAWT) Introduction to Digital System

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

1. Darrieus Wind Turbines

Horizontal axis wind turbine (VAWT) Construction

Missamraza , Hiren, Yogesh Mechanical Dept. LJ Polytechnic

Horizontal axis wind turbine (VAWT) Construction (Parts)

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Horizontal axis wind turbine (VAWT) Working of different Parts

Missamraza Mechanical Dept. LJ Polytechnic

Rotor- The hub and the blades together are referred to as the rotor. Wind turns the blades which turn the drive shaft.

Shaft- Two different shafts turn the generator. One is used for low speeds while another is used in high speeds.

Gear Box- Gears connect the high and low speed shafts and increase the rotational speeds from about 10-60 rotations per minute to about 1200-1800 rpm, the rotational speed required by most generators to produce power.

Horizontal axis wind turbine (VAWT) Working of different Parts

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Generator- The generator is what converts the turning motion of a wind turbine's blades into electricity. Inside this component, coils of wire are rotated in a magnetic field to produce electricity. Different generator designs produce either alternating current (AC) or direct current (DC), and they are available in a large range of output power ratings. The generator's rating, or size, is dependent on the length of the wind turbine's blades because more energy is captured by longer blades.

Controller- Turns the blades on at 8-16 mph and shuts them down around 65 to prevent any high wind damage.

Tower- Tall tubular metal shaft. The taller the tower, the more power produced.

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