1. WIND ENERGY

2. "Coal, gas and oil will not be the three kings of the energy
world for ever.

3. INTRODUCTION
 Energy is a major input for overall socio-economic
development of any society
 The prices of the fossil fuels steeply increasing
 So renewable are expected to play a key role
 Wind energy is the fastest growing renewable
 Wind turbines are up to the task of producing serious
amounts of electricity

4. What is a wind turbine?
A device for converting wind energy into mechanical or electrical
energy

5. How a Wind Turbine Works

6.  Wind turbine converts kinetic energy of wind to
rotary mechanical energy
 Blowing wind spins the blades on a turbine
 Blowing wind create a pocket of low pressure air
forms on downside of the blades , which pulls blades
towards it
 This is called Lift which cause the rotor to turn
 The rotor is connected to a shaft which causes a
generator to makes electricity

7. TYPES OF WIND TURBINE
THERE ARE BASICALLY TWO TYPES OF WIND
TURBINES NAMELY:
1.HORIZONTAL AXIS WIND TURBINE(HAWT)
2.VERTICLE AXIS WIND TURBINE(VAWT)

8. HAWT

9. HAWT Advantages
 Variable blade pitch, which gives the turbine blades the optimum
angle of attack. Allowing the angle of attack to be remotely adjusted
gives greater control, so the turbine collects the maximum amount of
wind energy for the time of day and season.
 The tall tower base allows access to stronger wind in sites with wind
shear. In some wind shear sites, every ten meters up, the wind speed
can increase by 20% and the power output by 34%.
High efficiency, since the blades always move perpendicularly to the
wind, receiving power through the whole rotation. In contrast, all
vertical axis wind turbines, and most proposed airborne wind turbine
designs, involve various types of reciprocating actions, requiring airfoil
surfaces to backtrack against the wind for part of the cycle.
Backtracking against the wind leads to inherently lower efficiency.
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10. HAWT Disadvantages
needs to be mounted on a high tower with high transport, installation &
maintenance costs;
very inefficient at low wind speeds;
unusable at high wind speeds, so wasting the most useful high energy winds
[Energy is proportional to wind velocity cubed];
environmentally problematic at the best locations;
noise & RF interference;
needs to be pointed at wind, which increases costs.
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11. VAWT

12. VAWT advantages
 Lower construction cost
Easier to maintain
Lower wind start-up speeds
 Less likely to break in high winds
 Low height
 Does not need to turn
 VAWTs are quieter and interfere less with TV, radio & radar signals
 VAWT systems can also directly drive pumps which may be used to store
wind generated energy.
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13. VAWT disadvantages
Current VAWTs are less efficient than HAWTs as some blades
always oppose wind flow;
Do not take advantage of the stronger wind at higher elevation as
the HAWTs do.
The stress in each blade due to wind loading changes sign twice
during each revolution as the apparent wind direction moves through
360 degrees. This reversal of the stress increases the likelihood of blade
failure by fatigue.
 While VAWTs' parts are located on the ground, they are also located
under the weight of the structure above it, which can make changing
out parts nearly impossible without dismantling the structure if not
designed properly.
 Having rotors located close to the ground where wind speeds are
lower due to wind shear, VAWTs may not produce as much energy at a
given site as a HAWT with the same footprint or height. 13

14. Advantages of Wind Energy
 Clean fuel source
 Domestic source
 Renewable power
 Lowest priced renewable energy technology available
today
 Benefits the economy

15. Disadvantages of Wind Energy
 Competition with conventional generation
sources
 Good sites often remote from where
electricity needed
 Concerns of noise and aesthetics impacts
 Environmental Concerns i.e. Birds