Wind and its uses

1. Effect of wind speed on power
generation and site selection

3. • Wind speed
• Air density
• Blade radius
https://www.youtube.com/watch?v=qSWm_nprfqE
P  Power
ρ  Air Density (kg/m3)
A  Blade Area -turbine (m2)
V  Wind velocity (m/s)
P = 0.5 X ρ X A X V3

5. Wind speed
• Cut-in speed: the cut-in speed (typically
between 6 and 9 mph) is when the blades
start rotating and generating power.
• As wind speeds increase, more electricity is
generated until it reaches a limit, known as
the rated speed. This is the point that the
turbine produces its maximum, or rated
power
Cut-off speed: cut-out speeds are related to the turbine design and size
and are decided on prior to construction.
As wind speed doubles, the power output will increase 8 times. This cubic
relationship is what makes wind speed such an important factor for wind
power.
Higher wind speeds generate more power because stronger winds
allow the blades to rotate faster. Faster rotation translates to more
mechanical power and more electrical power from the generator.

6. Air density
• the "heavier" the air, the more energy is received by the turbine.
• Power output is related to the local air density, which is a function of
altitude, pressure, and temperature.
• Dense air exerts more pressure on the rotors, which results in higher power
output
• a minimum wind speed (generally 12-14 km/h) to begin turning and
generate electricity. strong winds (50-60 km/h) to generate at full capacity.
winds of less than 90 km/h; beyond that speed, the turbines must be stopped
to avoid damage.

7. Blade radius
• Wind turbines are designed to maximize the rotor
blade radius to maximize power output.
• Larger blades allow the turbine to capture more
kinetic energy of the wind by moving more air through
the rotors.
• However, larger blades require more space and higher
wind speeds to operate.
• As a general rule, turbines are spaced out at four times
the rotor diameter.
• This distance is necessary to avoid interference
between turbines, which decreases the power output

8. Site selection
• the best locations in terms of wind resource are typically high
on mountains, in large open fields, or on the edge of
bodies of water. It is also important to consider the level of
wind shear on the proposed site.
• fairly consistent wind flow, travelling at just the right speed (not
too slow, yet not too fast)
• Other factors taken into consideration include relative proximity to
structures like buildings and houses, along with
possible environmental impacts of building the farm.
• Turbines must be spaced about 3 to 10 rotor diameters apart
(about 180-600 meters for a wind farm using 60 meter diameter
turbines)

9. What makes a site suitable for wind power?
• the tops of smooth, rounded hills; open plains and
water; and mountain gaps that funnel and intensify
wind. Wind resources are generally more favorable for
electricity generation at higher elevations above the earth's
surface
• factor is important for site selection for wind turbine?
• site power supply; health, safety and environmental
concerns; and low-temperature climate classifications,
among others.
• The wind velocity is usually high near seashore
Telangana's total installed capacity from wind power is 128 megawatts (MW)
including 100 MW from Pargi windmills and 28 MW from windmills on the
Hyderabad-Mumbai highway near Zaheerabad.

10. • Cut-off speed
• Cut-off speed

13. Application of wind mill.
.
i. For water pumping.
ii. When wind energy is produced it does not create any ill effect on
environment.
iii. For producing electric power.
iv. For running flour mill.
v. As stand by energy source.
vi. For running domestic appliances & lighting.
vii. For battery charging.
viii.The operating cost of windmill is very low.
ix. Combining with solar generation system to supply additional power.
x. Pumping Water for Irrigation
xi. It does not create greenhouse gases.
xii. Windmills in Warfare -used as watchtowers
xiii.It does not create greenhouse gases.
xiv.It does not produce toxic or radioactive waste.

14. Advantages of Wind Power
• The wind blows day and night, which allows windmills to
produce electricity throughout the day. (Faster during the day)
• Energy output from a wind turbine will vary as the wind varies,
although the most rapid variations will to some extent be
compensated for by the inertia of the wind turbine rotor.
• Wind energy is a domestic, renewable source of energy that
generates no pollution and has little environmental impact. Up to
95 percent of land used for wind farms can also be used for other
profitable activities including ranching, farming and forestry.
• The decreasing cost of wind power and the growing interest in
renewable energy sources should ensure that wind power will
become a viable energy source in the United States and worldwide.

15. advantages
• wind is a free resource
• it does not require fuel
• It does not create greenhouse gases.
• It does not produce toxic or radioactive waste
disadvantages
• wind energy is its intermittent supply
• an involuntary process and does not meet the
requirements always on time

16.  Wind Turbines and the Landscape
- Large turbines don’t turn as fast  attract less attention
- City dwellers “dwell” on the attention attracted by windmills
 Sound from Wind Turbines
- Increasing tip speed  less sound
- The closest neighbor is usually 300 m  experiences almost no
noise
 Birds often collide with high voltage overhead lines, masts, poles,
and windows of buildings. They are also killed by cars in traffic.
However, birds are seldom bothered by wind turbines.
 The only known site with bird collision problems is located in the
Altamont Pass in California.
 Danish Ministry of the Environment study revealed that power lines
are a much greater danger to birds than the wind turbines.
 Some birds even nest on cages on Wind Towers.