3. HOW WINDMILL WORKS:
◦Windmill converts
kinetic energy of wind
to mechanical energy.
◦Which then in turn
converted into
electrical energy by
connecting windmill to
the generator.
4. TYPES
HORIZONTAL AXIS WIND TURBINE (HAWT)
Have blades that rotates about horizontal axis parallel to wind.
1-Multiblade type
2-Sail type
3-Propeller type
VERTICAL AXIS WIND TURBINE (VAWT)
Have blades which rotates about vertical axis
1-Savanious type
2-Darrieus type
6. Multiblade type
◦ Has more number of blades
usually 12-20.
◦ Blades made of sheet metal or
aluminum.
◦ The width of plate increases
from center to periphery.
◦ The diameter of rotor ranges
from 2-5m.
◦ Low cost and used normally for
pumping water.
◦ Speed about 60 to 80 rpm.
7. Sail type
◦ Blade surface is made
of cloth or plastics
arranged in mast and
poles or sail wings.
◦ Runs at low speed
about 60-80 rpm.
8. Propeller type
◦ Turbine blades are shaped a lot
like airplane wings -- they use
an airfoil design. In an airfoil,
one surface of the blade is
somewhat rounded, while the
other is relatively flat.
◦ When wind travels over the
rounded, downwind face of the
blade, it has to move faster to
reach the end of the blade in
time to meet the wind
travelling over the flat, upwind
face of the blade
◦ Run at 300-400 rpm
9. Savanious type
◦ The savanious turbine is s-shaped
if viewed from above.
◦ It is relatively slow but yields high
torque.
◦ It consists of hollow circular
cylinder sliced in half, the two
halves fixed to vertical axis.
◦ Wind exert force greater fore on
cupped face than round face.
◦ The turbine rotates due to
pressure difference between
cupped face and round face.
◦ Efficient design but requires large
surface area.
10. Darrieus type
◦ Darrieus type looks like
an egg beater and has
two to three blades
shaped like an aero foil
◦ The fixed pitch blades are
curved an attached to
hubs on vertical shaft at
both ends.
◦ The curved blade has
shape like the rope
during skipping.
◦ It requires less surface
area.
11. HAWT
◦ HAWT have all there drive
train equipment located in
nacelle.
◦ Rotors must be oriented so
that blades are aligned with
wind.
◦ HAWT are placed on high
towers to access stronger
winds at greater heights.
◦ Propeller are most common
type of HAWT.
◦ Small wind turbine use tail fin
to align rotor with wind
direction.
◦ In modern turbines there is
yaw control system.
12. VAWT
◦ VAWT have all their drive
train on the ground
◦ Blades do not require
orientation with respect to
wind.
◦ They cannot readily be
placed on high towers to
exploit greater heights.
◦ Darrieus are most
common type of VAWT.
13.
14. Wind turbines
◦ Few watts to 2.5MW
◦ 2 to 6 blades
◦ 17.5 rpm to 30 rpm for 2MW
◦ 40 rpm to 60 rpm for 40KW t0 200KW
◦ Blade diameter ranges from 3.65m to 90m depending on capacity
◦ Material used for blades
• Canvas
• Wood
• Aluminum
• Reinforced fiber
• steel
