This document summarizes wind energy and wind turbines. It discusses how wind turbines work by using the kinetic energy of wind to spin blades and a shaft, which spins a generator to produce electricity. The main parts of a wind turbine are described as the blades, brake, nacelle, controller, gearbox, and generator. Advantages include being a clean, renewable resource, while disadvantages include fluctuations in wind and high installation costs. Horizontal axis and vertical axis wind turbines are compared. India is highlighted as a top investor in renewable energy and wind power producer.

1. G.L. BAJAJ INSTITUTE OF TECH.& MANAGEMENT
Prepared by-
Mr. Vishal Shankar Srivastava
(Asst. Prof.)
Department of Mechanical Engineering
Topic - Wind Energy

2. Table Of Content
Introduction
Principle
The parts
Working
Advantage
Disadvantage
Application
Reference

3. Introduction
Wind energy is a form of solar energy.
Wind is moving air and is caused by differences in air pressure within
our atmosphere. Air under high pressure moves toward areas of low
pressure. The greater the difference in pressure, the faster the air flows. [1]
Wind energy (or wind power) describes the process by which wind is used
to generate electricity. Wind turbines convert the kinetic energy in
the wind into mechanical power. A generator can convert mechanical power
into electricity.
At least 16 km/h winds.[2]

4. Principle
• The basic principle of every
windmill is to convert
kinetic energy of wind into
mechanical energy which is
used to rotate the turbine of
electrical generator to
produce electricity.[2]
Fig: Wind mill [5]

5. Parts of the Wind Mill
Anemometer: Measures the wind speed
Blades: Most turbines have 2 or 3. Wind blowing over the blades causes the blades to lift and rotate
Brake: A disc brake can be used to stop the rotor in emergencies.
Nacelle: The nacelle sits at top of the tower and contains the gear box, low- and high-speed shafts, generator,
controller, and brake. Some nacelles are large enough for a helicopter to land on.
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.
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 most
generators to produce electricity. The gear box is a costly (and heavy) part of the wind turbine and engineers
are exploring "direct-drive" generators that operate at lower rotational speeds.
Generator Usually an off-the-shelf induction generator that produces 60-cycle AC electricity.

6. Parts of the Wind Mill [6]

7. Working [7]
• A wind turbine works the opposite of a fan
• The wind turns the blades, which spin a shaft,
• Which connects to a generator and makes electricity.

8. Advantage:
• Advantages of Wind Power.
• Wind power is cost-effective.
• It's a clean fuel source.
• Wind is a domestic source of energy.
• It's sustainable.
• Wind turbines can be built on existing farms or ranches.

9. Disadvantage :
• The Wind fluctuates.
• Wind energy has a similar drawback to solar energy in that it is not constant.
• Installation is expensive although costs are reducing over time, wind turbines are
still expensive.
• Wind turbines pose a threat to wildlife.
• Wind turbines create noise pollution.
• They also create visual pollution.

10. Types of windmills [2]
 Horizontal axis wind turbines
• Tall towers enable accessing stronger winds
• Blades capture wind energy throughout rotation
• Strong and huge towers required
• Complexity during construction
• Need to be turned to face the wind
Vertical axis wind turbines
• Generates power independent of wind direction
• Low cost
• Strong tower not needed since generator is on the ground
• Low efficiency (only one blade works at a time)
• May need wires to support
• More turbulent flow near ground

11. Horizontal axis & Vertical axis wind turbines Image [8]

12. Energy calculations:[2]

13. Power generated: [2]

14. Power as a function of wind speed: [2]

15. Space requirement: [2]
• Rule of thumb is 7 times diameter of windmill.
• Approximately 500 m from other turbines.
• Each 2 MW turbine needs approximately 0.5 square km.

16. Application of wind energy-[2]
• Typically it is used in charging of the batteries which is useful to
store energy captured by wind turbines.
• Water pumping is the key historical application of the wind energy.
• Main key competitive area of the wind energy is that remote off grid
power applications.
• Grinding grains.

17. India investment in Renewable Energy - [3]

18. Top Wind Power Producing Country [3]

19. References:
[1] https://eo.ucar.edu/basics/wx_2_c.html
[2]https://nptel.ac.in/content/storage2/courses/121106014/Week8/lecture24.pdf
[3]https://en.wikipedia.org/wiki/Wind_power_by_country
[4] https://en.wikipedia.org/wiki/Wind_power_in_India
[5] https://images.app.goo.gl/cCvReyuWNoUdRgaX8
[6] https://images.app.goo.gl/brSmn3k93nYLfCRJ8
[7] https://images.app.goo.gl/LSZxtY5yJFh2qd1i9
[8] https://images.app.goo.gl/pSoP5yqtsuuT6WEm8