The document discusses wind power as a source of renewable energy. It describes how wind is formed by uneven heating of the earth's surface, and explains that the amount of electricity produced from wind turbines depends on wind speed, turbine availability, and turbine arrangement. It then discusses two types of wind power plants - onshore and offshore. Onshore plants have lower costs but offshore plants access stronger winds. The document outlines the basic working mechanism of a wind turbine in converting kinetic wind energy to electrical energy. It also discusses factors for selecting wind power plant sites and describes the two main types of wind turbines: horizontal axis and vertical axis.
2. Introduction:
The standard of living of the people of any country is
considered to be proportional to the energy
consumption by the people of that country.
Old Sources of energy are lacking in providing
sufficient Energy to Energy Demands.
The World ,particularly developing countries needs a
new energy sources because of growth in world
population and growth in energy demand.
3.
4.
5. How Does Wind Blow:
The sun heats the earth’s
Surface unevenly. As heat
is transferred to the air, we
get regions of warm and
cool air which can turn
into regions of low and
high pressure. This
difference in pressure
makes a force that causes
the wind to blow.
6. Electricity Produced : The amount of electricity produced from a wind
turbine depends on three factors:
1) Wind speed
•function of the cube of the wind speed
• if the wind blows at twice the speed, its energy content will
increase eight-fold.
2) Wind turbine availability
•This is the capability to operate when the wind is blowing,
i.e. When the wind turbine is not undergoing maintenance.
3) The way wind turbines are arranged
•Wind farms are laid out so that one turbine does not take the
wind away from another.
9. 1. On-Shore Power Plants:- On-shore wind power
refers to the construction of wind farms on land or on shores
of sea to generate electricity.
Advantages:
1. Less Erosion
2. Less Maintenance cost
3. Less Capital cost
10.
11. 2. Off-Shore Power Plants:- Offshore wind power
refers to the construction of wind farms in large bodies of
water to generate electricity
Advantages:
1. More Wind
2. Less Harm to Birds
3. Limitation of the area & Visual Impact
4. Acoustic noise
12. Wind Mills Are Harming Birds:
Approximately 40,000 birds
each year die by flying into wind
turbines on land in the United States.
13. Working Of a Wind Turbine: Wind turbines produce electricity by using
the natural power of the wind to drive a generator.
Steps:
•Wind passes over the blades exerting a turning force.
•The rotating blades turn a shaft inside the nacelle, which goes
into a gearbox.
•The gearbox increases the rotation speed for the generator, which uses magnetic
fi elds to convert the rotational energy into electrical energy.
•The power output goes to a transformer, which converts the electricity
from the generator at around 700 Volts (V) to the right voltage for the distribution
system, typically between 11 kV and 132 kV.
•The regional electricity distribution networks or National
Grid transmit the electricity around the country, and on into homes and businesses.
14. Principle Of Energy Conversion : Windmills or turbines
works on the principle of converting kinetic energy of the wind in to
mechanical energy.
Power available from wind mill-
P= ½d A V³
Where-
d :- air density = 1.225 Kg. / m³ at sea
level.(changes by 10-15% due to
temperature and pressure variations)
A :- area swept by windmill rotor =
dD² sq-m. (D – diameter )
V – wind speed m/sec.
15. Installing a Wind Power Plant:
1.) Site Selection : Following factors are to be considered for
selection of good site for wind power generation: -
•High annual wind speed.
•No tall obstructions for a radius of 3 Km.
•Open plain or open shore
•Top of a smooth, well rounded hill with gentle slopes
•Mountain gap which produces wind funneling.
17. 1. Horizontal Axis Wind Turbines (HAWT)
•A HAWT has a similar design to a windmill
•It has blades that look like a propeller that
spin non the horizontal axis.
18. HAWT Advantages:
•The tall tower base allows access to stronger wind in sites
with wind shear.
•High efficiency, since the blades always move
perpendicularly to the wind, receiving power through the
whole rotation.
•Does not need reciprocating actions, requiring airfoil surfaces
to backtrack against the wind for part of the cycle.
19. HAWT Disadvantages:
• Required Massive tower construction
•Obtrusively visible across large areas
•Downwind variants suffer from fatigue and structural
failure.
•Require an additional yaw control mechanism
•Require a braking device
20. 2. Vertical axis [VAWTs]
•Have the main rotor shaft arranged
vertically.
•By such arrangement is that the wind
turbine does not need to be pointed
into the wind.
•This is an advantage on sites where
the wind direction is highly variable
or has turbulent winds.
21. VAWT Advantages:
•No yaw mechanisms is needed.
•Can be located nearer the ground
•Lower wind startup speeds
•May be built at locations where taller
structures are prohibited
22. VAWT disadvantages
•average decreased efficiency from a common HAWT,
mainly because of the additional drag.
•Having rotors located close to the ground