This document discusses the history and current state of wind energy. It begins by covering the early history of windmills from the late 19th century, when they were used primarily for mechanical tasks like grinding grain. Over time, windmills were adapted to generate electricity. By the late 20th century, wind energy development slowed due to cheap fossil fuels but regained interest due to the 1973 oil embargo. Modern wind turbines convert the kinetic energy of wind into mechanical power using rotating blades and generators. Wind energy now provides around 4% of global electricity and is a leading renewable source in some countries and regions.

1. UNIT 3
Wind Energy Systems and Current
technologies in wind energy

2. History of Wind Energy
 Until the late nineteenth century windmills would only produce mechanical
power for their tasks such as grinding grain or pumping water.
 With the creation of electricity, windmill makers found that windmills could be
attached to a generator and used to create power for heating and lighting.
 The first windmill used to produce electric energy was created in 1888 by
Charles F. Brush.
 By the end of the nineteenth century there were over 30,000 windmills in
Europe. They were used for more than just pumping water and grinding grain,
people used them to run saw mills and other industrial plants.
 These windmills needed to produce 500 revolution per minute in order to power
a generator.

3.  From the 1930’s to the 70’s coal and oil were relatively inexpensive and wind
energy lost its popularity in America though windmills were used in many
other countries throughout the world
 In 1973 America was affected by the Arab oil embargo. This caused
focus to turn toward wind power.
 The U.S. Federal Wind Energy Program was established in 1974.
 By the late 1980’s it was becoming very difficult to attract funding for wind
energy because people did not believe that wind power could be strong
enough to produce the same amount of power as oil.
 Modern wind power is a strong option for alternative energy, and its rich
history proves it can be used effectively
History of Wind Energy

4. Wind Energy is an indirect form of solar energy which can be used continuously
unlike solar energy
Wind energy classified in two types
1.- Planetary winds
2.- Local winds
Planetary winds are cause due to greater heating of earth’s surface near the
equator as compared to solar heating near the south & north poles.
Local winds are caused due to differential heating of land & water in coastal
areas these are due to uneven heating in hills and mountains along the slopes.
Wind is a form of solar energy. Winds are caused by the uneven heating of the
atmosphere by the sun, the irregularities of the earth's surface, and rotation of the
earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and
vegetative cover. This wind flow, or motion energy, when "harvested" by modern
wind turbines, can be used to generate electricity.
Concept of Wind Energy

5. Wind Energy as renewable energy resource
Wind energy is a form of solar energy. 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.
Mechanical power can also be utilized directly for specific tasks such as pumping water.
Wind Energy basics
Wind is caused by the uneven heating of the atmosphere by the sun, variations in the earth's
surface, and rotation of the earth. Mountains, bodies of water, and vegetation all influence
wind flow patterns. Wind turbines convert the energy in wind to electricity by rotating
propeller-like blades around a rotor. The rotor turns the drive shaft, which turns an electric
generator. Three key factors affect the amount of energy a turbine can harness from the wind:
wind speed, air density, and swept area.
Global Wind Energy contribution
At the end of 2019, worldwide installed wind power capacity was 623 GW. Wind-generated
electricity met nearly 4% of global electricity demand in 2015, with nearly 63 GW of new
wind power capacity installed. Wind energy was the leading source of new capacity in
Europe, the US and Canada, and the second largest in China. In Denmark, wind energy met
more than 40% of its electricity demand while Ireland, Portugal and Spain each met nearly
20%.

6. Components of Wind Turbine

7. Wind turbines are used to generate electricity from the kinetic power of the
wind.
Wind turbines convert the kinetic energy in the wind into mechanical power.
This mechanical power can be used for specific tasks ( a generator can
convert this mechanical power into electricity)
The energy in the wind turns two or three propeller-like blades around a rotor.
The rotor is connected to the main shaft, which spins a generator to create
electricity.

8. Main components of wind turbine are shown below: