Understanding wind power made easy

Centre for application of renewable energy
http://www.windpower.co.nr
http://www.careindia.co.nr
p //
Care.india@live.co.uk
windpower@live.co.uk

WIND POWER
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Wind is Sun's heat transformed into kinetic energy through the greatest solar
collector currently available, Earth's atmosphere. Wind total power is estimated
between 1 700 and 3 500 TeraWatt; by comparison, the whole mankind primary
y p p y
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energy needs are estimated at approx. 14 TW.

Wind energy is not uniformly distributed, but mainly found in the higher layers of
the troposphere at th mid l tit d of b th N th and S th h i h
th t h t the id latitudes f both North d South hemispheres. Th The
most favourable altitude in term of wind power is, quite difficult to exploit, at
approx. 10 000 m (32 800 ft), where average wind speeds can exceed 45 m/s
( q
(equal to 162 km/h or 100 mph).
/ p )

At 250 hecto Pascal (measure of atmospheric pressure, equal to millibar)
equivalent to approx. 10 400 m of altitude From these heights, wind speed and
energy ddecrease moving towards the ground, the l
i d h d h layers of air giving b k h
f i i i back heat
through friction between them and with the topography of the Earth's surface. In
the below graphic at 500 hPa (approx. 5 600 m of altitude) average wind speeds
are already significantly reduced.
dy g y d d

CENTRE FOR APPLICATION OFRENEWABLE ENERGY WEBSITE : http://www.careindia.co.nr email : windpower@live.co.uk

Wind Potential
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Global Scenario
World top 10 Renewable Electricity Producers
World top 10 Renewable Electricity Producers
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Source : http://en.wikipedia.org/wiki/List_of_countries_by_electricity_production_from_renewable_sources
Other
Oh
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Hydro- Wind Geo-
Rank Country Year Total Biomass Solar sources
electricity Power thermal *

1 China 2009 576.9 549 40.2 3 0.14
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European
- 2009 587.2
Union[6]
2 United States 2009 424.3 272.1 70.8 54.3 0.808 15.2

3 Brazil 2009 409.8 387.1 1.374 21.354

4 Canada 2009 374.5 363.2 2.5 0.017

5 Russia 2009 165.1
165 1 163.2
163 2 0.007
0 007 0.48
0 48 0.41
0 41

6 Norway 2009 126.2 125 0.977 0.2

7 India 2009 121.8 104.4 14.7

8 Germany 2010 101.7 19.694 36.5 33.46 12 0.027

9 Japan 2009 98.9 75.2 1.754 0.002 3.027

10 Venezuela 2009 85.8 85.8


Global Scenario
World top 10 WIND POWER Electricity Producers
World top 10 WIND POWER Electricity Producers
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# Top 10 countries by nameplate WIND POWER capacity (2010)**
WIND POWER (2010)
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1 China 44,733

2 United States 40,180
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3 Germany 27,215

4 Spain 20,676

5 India 13,066
6 Italy 5,797
7 France
F 5,660
5 660
8 United Kingdom 5,204
9 Canada 4,
4,008
10 Denmark 3,734
** World Wind Energy Report 2010. World Wind Energy Association. February 2011.
Retrieved 8 ugus 0
e e ed 8-August-2011. http://www.wwindea.org/home/images/stories/pdfs/worldwindenergyreport2010_s.pdf


Wind Generation
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In the year 2010, the wind capacity reached worldwide 196 630 Megawatt,
after 159 050 MW in 2009, 120 903 MW in 2008, and 93 930 MW in 2007
the installed wind capacity more than doubled every third year.
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In the year 2010, altogether 83 countries, one more than in 2009, used wind
energy for electricity generation. 52 countries increased their total installed
capacity, after 49 in the previous year.

At the end of 2010, worldwide nameplate capacity of wind-powered generators
was 197 gigawatts (GW). Wind power now has the capacity to generate 430
TWh annually, which is about 2.5% of worldwide electricity usage. Over the
y, 5 y g
past five years the average annual growth in new installations has been 27.6
percent. Wind power market penetration is expected to reach 3.35 percent by
2013 and 8 percent by 2018. Several countries have already achieved relatively
high levels of wind power penetration, such as 21% of stationary electricity
g p p , y y
production in Denmark, 18% in Portugal, 16% in Spain, 14% in Ireland [9] and
9% in Germany in 2010. As of 2011, 83 countries around the world are using
wind power on a commercial basis.


Best Locations for Wind Power
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What kind f i d is
Wh ki d of wind i needed to generate
d d
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enough power to do the job. If you are
producing electricity for instance, you'll need
to be receiving an adequate amount of
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electricity for the wind turbine to pay for itself
in a reasonable amount of time.
However, there are exceptions. For instance, if
you live in a higher elevation than most of the
surrounding terrain, or along a uniquely
situated "wind tunnel," you will probably have
more wind than any chart would show
One method of determining the amount of
wind your area of the country receives is to
consult average wind speed data at your
g p y
nearest airport weather station. Of course, the
below chart will help as well.


Wind Potential (
(Height)
g )
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One of main deciding factor about the efficiency At 80 m above the ground, the hub height
of wind turbines is the height of tower underlying representative of the latest generation of
the windmill. In most of cases the greater height of wind turbines, the global average wind
the tower is preferred with a objective to harness the
p j speed is estimated at 4 6 m/s not enough
4.6 m/s,
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available wind power to maximum extent. for economical wind power generation; at 10
Sometimes tower goes up to 65 meters in sky. m above the ground is even lower, estimated
Consequently there is seen a general trend in favour at 3.3 m/s (see Evaluation of global wind
of high towers these days. E very point on the Earth power,
power Cristina L Archer - Mark Z
L. Z.
surface, on average, 800 m above it, has enough Jacobson, Journal of Geophysical Research
wind power to be exploited – Atmospheres, 2005).

Altitude Wind speed Wind power But
B to b k f
break free ffrom the ground and to
h d d
reach altitude winds is already very
m m/s W/m²
beneficial at 800 m, the height
800 7
7.2 205
5 representative of a Kite Gen power plant,
where the average wind speed i estimated
h h i d d is i d
80 4.6 58 by Kite Gen Research at 7.2 m/s. At this
altitude wind power, as shown by the
10 3.3 22 following table, is almost 4 times the
amount available t wind t bi
t il bl to i d turbines.


A WIND TURBINE
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Advantages of new systems to optimize the
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efficiency of wind turbines and their blades
•They reduce noise.
•They reduce vibration.
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New developments that are being worked
out to make wind turbines and blades more
efficient
The overall working scope of the wind
turbine can be enlarged by using the flow
control on the outboard side of the blade
beyond the half radius Attempts are being
radius.
made to increase the rated output power
without increasing the level of operating
range.
Scientists are also trying to attain a greater
efficiency by placing blades at various
angles through wind tunnel tests of 2.5
megawatt turbine airfoil surfaces and
computer simulations.

A WIND TURBINE
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Wind
Wi d turbines use l
bi large bl d to catch
blades h
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the wind. When the wind blows, the
blades are forced round, driving a
turbine which generates electricity. The
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stronger the wind, the more electricity
produced.
There are two types of domestic-sized
wind turbine:
Pole mounted: these are free standing
and are erected in a suitably exposed
position,
position often around 5kW to 6kW
Building mounted: these are smaller
than mast mounted systems and can be
installed on the roof of a home where
there is a suitable wind resource. Often
these are around 1kW to 2kW in size.


Small wind energy
gy
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Small
S ll wind energy systems,
i d t
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namely water pumping
windmills, aero generators and
wind-solar
wind solar hybrid systems can
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also be used for harnessing wind
power potential, in addition to
the large capacity wind turbines
turbines.
These systems have been found to
be very useful for meeting water
pumping and small power
requirements in decentralised
mode in rural and remote windy
areas of the country, which
are un-electrified or have
intermittent electric supply.


Turbine Characteristics
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General advantages of wind turbines are the complete absence of
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air pollution and a high energy-conversion efficiency. Well-
designed wind turbines can recover up to 60- 80% of the kinetic
energy from the flow passing through their rotors. However, the
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low energy density available in the wind typically restricts output
to a range 0.1 to 0.8 kW/m2 (kilowatts per square metre) of the
rotor's projected area. The result is a large machine size in
relation to output; f example, i a machine rated at 5 MW
l i for l in hi d
(MW=106 W), a high output for a single wind turbine, the rotor
diameter can be as large as 100 m. This size problem results in
the use of clustered machines known as wind farms to extract
machines, farms,
large power outputs from individual sites. Another problem with
wind-energy systems is the variability of wind strength, which
leads to substantial fluctuations in power since output is roughly
proportional to the cube of the wind speed. Furthermore, all
wind-energy conversion devices incur additional costs because
they must be capable of withstanding storms.
y p g


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Different t bi characteristics are required f
Diff t turbine h t i ti i d for
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each type of application. Most electrical-power
generators, or alternators, tend to require a
relatively high speed of rotation. Consequently,
turbines th t run f i l f t with th ti of th
t bi that fairly fast, ith the tips f the
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rotor moving 3-10 times the wind speed, are
generally preferable to low-speed turbines
because less gearing is required between the
shaft of th wind t bi and th armature of
h ft f the i d turbine d the t f
the generator. A relatively low running speed is
generally favoured for wind turbines that are
directly coupled to water pumps or other
mechanical l d A striking f t
h i l loads. t iki feature of wind
f i d
turbines intended for high-speed operation is
the low rotor solidity, that is, the very small
blade area in proportion to the turbine rotor's
total
t t l projected area. l
j t d low-speed t bi
d turbines f t
feature
a high solidity (either a small number of
relatively broad blades or a large number of
narrower ones).


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The most common form of low-speed
low speed
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machine is the horizontal axis, multi
bladed form often found on farms. The
turbine is usually connected, via a
crank, to a reciprocating water pump. A
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related design is the multi bladed
"bicycle-wheel" turbine, an example of
a relatively low-speed turbine used for
electrical-power generation. A simple
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vertical-axis design, often used for
water pumping, is the split cylinder
configuration known as the Savonius
rotor, after its originator. In this
turbine each of the 2 or 3 rotor bl d
bi h f h blades
consists of a semi cylinder offset
radially from the axis of rotation. The
design relies, in part, on a drag effect
for its
f it operation. It i not, th f
ti is t therefore, a
particularly efficient configuration, but
is relatively simple to make.


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All modern high speed turbines and
high-speed
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most of the low-speed units incorporate
blades designed on airfoil principles.
Some inefficient low-speed machines
depend on a drag effect as does a
effect,
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square-rigged sailing ship. The
foregoing remarks apply equally to wind
turbines that are arranged with
horizontal or vertical axes of rotation
rotation.
Typical horizontal-axis high-speed wind
turbines have either 2 or 3 blades and
resemble aircraft propellers. The blades
of these machines are commonly
arranged to vary in pitch automatically
to optimize performance under
conditions of varying wind speed. The
most common high-speed vertical-axis
g p
turbine is the Darrieus rotor, named for
its inventor. This machine is also known
as an "egg beater" because of its
characteristic appearance


Savonius Wind Turbine
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Savonius is a type of vertical axis wind turbine (VAWT) generator. The
Savonius is adrag-type VAWT which operates in the same way as a cup
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anemometer Savonius wind turbines typically only have an efficiency of
around 15% - i.e. just 15% of the wind energy hitting the rotor is turned into
rotational mechanical energy. This is much less than can be achieved with a
Darrieus wind turbine (which useslift rather than drag.
The speed of the cups of a cup anemometer (and aSavonius wind turbine)
cannot rotate faster than the speed of the wind and so they have a tip speed
ratio(TSR) of 1 or below. Therefore Savonius type vertical axis wind turbines
turn slowly but generate a high torque
torque.
This does not make them very suitable for electricity generation since
turbine generators need to be turned at hundreds of RPM to generate high
voltages and currents. A gearbox could be employed but the added resistence
would l
ld leave the S
h Savonius requiring a very strong wind to get spinning - i i
i i i i d i i i.e. it
typically would not self-start.


Darrieus Wind Turbine
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A Darrieus is a type of vertical
axis wind turbine (1) (VAWT)
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generator. Unlike the Savonius
wind turbine (2), the Darrieus
is
i a lift t
lift-type VAWT R th
VAWT. Rather
than collecting the wind in cups
dragging the turbine around, a
Darrieus uses lift forces
generated by the wind hitting
aerofoil’s to create rotation.


Benefits :
Darrieus Wind Turbine
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A Darrieus wind turbine can spin at many times the speed of the wind
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hitting it (i.e. the tip speed ratio (TSR) is greater than 1). Hence a
Darrieus wind turbine generates less torque than a Savonius but it rotates
much faster. This makes Darrieus wind turbines much better suited to
electricity generation rather than water pumping and similar activities
activities.
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The centrifugal forces generated by a Darrieus turbine are very large and
act on the turbine blades which therefore have to be very strong - however
the forces on the bearings and generator are usually lower than are the
case with a Savonius.
ih i
Darrieus wind turbines are not self-starting. Therefore a small powered
motor is required to start off the rotation, and then when it has enough
speed the wind passing across the aerofoil’s starts to generate torque and
aerofoil s
the rotor is driven around by the wind.
An alternative is shown in the illustration above. Two
smallSavonius rotors are mounted on the shaft of the Darrieus turbine to
start rotation. These slow down the Darrieus turbine when it gets going
however they make the whole device a lot simpler and easier to maintain


Distribution Weibull
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In order to calculate the likely power output from a given wind
turbine it is necessary to understand the wind in the planned
turbine location. It is very easy to find theaverage wind
speed i a l ti
d in location
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Wind speeds in most of the world can be modeled using
the Weibull Distribution. This statistical tool tells us how often
winds of different speeds will be seen at a location with a certain
average (mean) wind speed. Knowing this helps us to choose a
wind turbine with the optimal cut-in speed (the wind speed at
which the turbine starts to generate usable power), and the cut-
g p
out speed (the speed at which the turbine hits the limit of its
alternator and can no longer put out increased power output with
further increases in wind speed).
Weibull Distribution and Wind Speeds (http://www windpower co nr)
(http://www.windpower.co.nr)
Calculations visit http://www.windpower.co.nr)


Real World Wind Turbine
Power
Po er Efficiencies
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The theoretical maximum power
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efficiency of any design of wind turbine Horizontal axis wind turbines (HAWT)
is 0.59 (i.e. no more than 59% of the theoretically have higher power efficiencies
energy carried by the wind can be than vertical axis wind turbines (VAWT)
extracted by a wind turbine) Once you
turbine). however wind direction is not important for
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also factor in the engineering a VAWT and so no time (and power) is
requirements of a wind turbine - wasted chasing the wind. In turbulent
strength and durability in particular -
the real world limit is well below conditions with rapid changes in wind
the Betz Limit with values of 0.35-0.45 direction more electricity will be generated
common even in the best designed wind by a VAWT
turbines. By the time you take into
account other inefficiencies in a
complete wind turbine system - e.g. the
generator, bearings, power transmission
and so on - only 10-30% of the power of
the wind is ever actually converted into
y
usable electricity. (see the graphic above
from the Iowa Energy Center, USA.)



Betz Limits
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Albert Betz was a German physicist who in
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1919 concluded that no wind turbine can
convert more than 16/27 (59.3%) of the
kinetic energy of the wind into mechanical
energy turning a rotor. To this day this is
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known as the Betz Limit or Betz' Law. This
limit has nothing to do with inefficiencies
in the generator, but in the very nature of
wind turbines themselves.
Wind turbines extract energy by slowing
down the wind. For a wind turbine to be
100% efficient it would need to stop 100%
of the wind - but then the rotor would have
to be a solid disk and it would not turn and
no kinetic energy would be converted. On
the other extreme, if you had a wind
turbine with just one rotor blade, most of
the wind passing through the area swept by
the turbine blade would miss the blade
completely and so the kinetic energy would
be kept by the wind.


Power Efficiencies
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“When h i d blows, a pocket of l
“Wh the wind bl k f low
pressure air forms, pulling the blade
toward it, causing the rotor to turn. This
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is called lift. The “When the wind
blows, a pocket of low pressure air
forms, pulling the blade toward it,
, p g ,
causing the rotor to turn. This is called
lift.

The turbines that use a new, low wind
speed technology. The sweep twist
adaptive blade automatically twists to
reduce stress on the turbine from the
mechanical load produced during high
wind.
i d

HAWT’s
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A standard HAWT (Horizontal Axis
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Wind Turbine)captures the wind’s
energy with three propeller-like
blades mounted on a rotor. The
turbine sits more than 200 f
bi i h feet atop a
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tower to take advantage of stronger
and less-turbulent wind.

Elevated so high above the surface
makes maintenance and repair costly;
bearings and shafts that transfer wind
p
power from the turbine blades must
be to withstand exceptional rigors in
various weather conditions.

BUT ……Newer HAWTs can make
Newer
use of wind at lower velocities; such
advanced design has meant the
addition of utility scale wind turbines
in less windy (Class Four*) areas
Four )


Power Efficiencies
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Wind power classes designate a range of mean wind power density of
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approximate wind speed at specified heights above the ground. Areas
designated as “Excellent” have wind power Class Five or greater, and
are suitable for utility-scale wind energy applications. These areas
represent regions where the wind power density exceeds 500
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watts/m2 at 50m above the ground. Areas designated as “Good” have
wind power at four or better, and are also suitable for utility scale wind
energy applications.
Nevertheless, these advanced designs can have increased stress at
higher velocities requiring the turbine to be stopped or the drive train
disengaged. The innovative wind blade, which Knight & Carver’s Wind
Blade Division has developed can operate over a wider range of wind
developed,
speed thereby increasing the amount of energy that a low wind speed
turbine can produce.
Sized at 27.2 (85 ft) meters x 2.4 meters (7 ft),
7 ( 5 ) 4 ),
the Adaptive Sweep Twist Blade is designed both for maximum
efficiency at lower-speed wind conditions and to automatically adjust
to higher wind gusts when necessary.


Vertical Axis Wind Turbine
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Horizontal axis wind turbines (HAWT)
theoretically have higher power
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efficiencies than vertical axis wind
turbines (VAWT) however wind
direction is not important for a VAWT
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and so no time (and power) is
wasted chasing the wind. In turbulent
conditions with rapid changes in wind
p g
direction more electricity will be
generated by a VAWT


Vertical Axis Wind Turbine
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10KW C type VAWT technique parameter

Power 10kw

The diameter of wind wheel 4.5m
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Rated rotate speed 150(r/min)

Rated wind speed 10 m/s

Start up wind speed 3m/s

Working wind speed 3-30(m/s)
3 30(m/s)

Security wind speed 50(m/s)

Rated power 10kw

The max power 12kw

Output voltage 220v

The height of tower 12m

The top part weight 380kg

Guy cable tower type 273 steel pipe

Output control system Charger control,inverter

Necessary battery 12v200ah, 30 pcs


F.A.Q’S
Q
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What are the advantages of wind energy?
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Wind is a renewable energy resource. Coal, oil and natural gas are
nonrenewable. No emissions are released into the atmosphere. Other
energy resources release carbon dioxide and greenhouse gases when they
are burned Environmental effects of mining and well drilling are avoided
burned. avoided.
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Wind generates electricity without bringing in fuel from outside the state.

Are wind turbines reliable and safe?
The turbines are, on average, operational and ready to run during more
than 95% of the year. They are very safe. Redundant braking systems slow
and stop the rotation of the blades (aerodynamic and mechanical braking
systems). The blades have been thoroughly tested for strength and
fatigue over time. Th strong towers are h ll
f i i The hollow and offer safe access f
d ff f for
service personnel.
How close are the turbines to homes or roads?
Where the turbines are placed is highly dependent on factors such as
wind strength and aesthetics. They are not placed within 800 feet of
residences and 300 feet from public or developed roads.


F.A.Q’S
Q
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Are i d
A wind turbines noisy?
bi i ?
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Today’s wind turbines are very quiet. At 200 yards, the swishing
sound of rotor blades is usually masked completely by wind noise in
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the leaves of trees or shrubs. Even with the steps taken to reduce wind
turbine noise, some noise is produced.

We are required to maintain a noise level less than 50 dBa at any
nearby home. Tests have shown that we are below the required level.
Examples of noise:*

Rock concert 110 dBa Diesel truck 90 dBa

Vacuum cleaner 70 dBa Normal conversation 60 dBa

Soft whisper 30 dBa Jet taking off 120 dBa


F.A.Q’S
Q
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What happens to a site where wind turbines are no longer
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needed?
The turbines at the MGE site should operate for at least 25 years. At the
end of their useful life we anticipate that the site will be repowered with
life,
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new turbines.
Which turbine is suitable for my needs?
A medium sized average home requires between 4–6 MWh of energy
per annum. A school, office, community centre or f
h l ffi i farm will almost
ill l
certainly use a lot more.An assessment of the power requirements of
your particular application and a wind speed assessment of your site, will
need to be made in order to determine which turbine will meet all your y
needs, however the question may not be as important as you might
imagine ...
The wind turbine, and your property, will be connected to the national
grid,
grid so whenever you need more power than the wind turbine can
produce, it will simply come from your electricity supplier as it does now.
When your turbine produces more power than you need, it is exported to
the grid, and you get paid for the surplus.


F.A.Q’S
Q
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How d wind turbines generate electricity?
H do i d bi l i i ?
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Wind turbines have a rotor (a hub with three blades), a power
shaft and a generator to convert wind energy into
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electrical energy. Wind passes over the rotor and makes it spin.
This spinning motion is used by the generator to produce
electricity.
y
The amount of energy produced depends on wind speed and the
diameter of the rotor. Because wind speed increases with height,
the wind turbines are mounted on towers. A good location for
wind turbines should have average annual wind speeds of at
least 12 miles per hour. Small changes in average wind speed are
important.
important Even a one-mile-per-hour increase in wind speed
one mile per hour
makes a significant difference in the power available to generate
electricity.


F.A.Q’S
Q
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Do the turbines affect TV or radio reception?
Several thousand towers have been erected . The majority of these
turbines h
bi have not caused any signal i
d i l interference. MGE sited the
f i d h
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wind turbines to minimize signal interference. MGE fixed any TV
signal problems nearby neighbors had.
Are birds affected by wind turbines?
Care is taken to locate wind turbines away from sensitive wildlife
areas such as wetlands and migratory paths. MGE’s wind site was
MGE s
reviewed by independent agencies for environmental impacts
including bird mortality. Ongoing studies at our site have
shown that bird mortality has not been a problem
problem.


F.A.Q’S
Q
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What happens when the wind doesn’t blow?
The turbines are dependent on the wind to produce electricity. On a
calm day, the turbines won’t be able to produce power. But
won t
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electricity is still available; other power plants will adjust their
output to make up the difference.
What happens if lightning strikes a wind turbine?
Each wind turbine is protected from lightning by a grounding
system. In the event of a strike, the system guides the electrical
energy safely to ground. Thi system i similar to the li h i
f l d This is i il h lightning
Can wind turbines blend into the landscape?
The turbines are located in open terrain to have access to the wind.
e tu b es a e ocated ope te a ave t e w d.
Better equipment designs and careful planning dramatically
improve the appearance of wind farms.


INNOVATIONS
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Storing Wind Power with Compressed Air
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Pumped Hydro– An Alternative Technology
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INNOVATIONS
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Storing Wind Power with
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Compressed Air
Find out how wind power can be
stored and sold at times of peak
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demand
Wind power suffers from one
major problem
majo p oblem - the wind is very
ind e
fickle. If wind turbines are to be a
viable large scale replacement for
coal-
coal and gas fired power stations
gas-fired stations,
a way has to be found to capture
and store the energy from the
wind so that it can be put to use
when it is needed, and not just
when the wind is blowing.
(Credit: PG&E)


Storing Wind Power
with Compressed Air
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Wind power suffers from one major
p
problem - the wind is very fickle. If wind
y
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turbines are to be a viable large scale
replacement for coal- and gas-fired
power stations, a way has to be found to
capture and store the energy from the
p gy
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wind so that it can be put to use when it
is needed, and not just when the wind is
blowing.

Since electricity from wind turbines is
more expensive than that generated by
conventional power stations, another
benefit of storing wind power is that
electricity can be exported to the
National Grid at peak times of day when
the price paid for it can be 2 or 3 times
g
greater that at off peak times. This
p
makes wind turbine generators
financially viable without the need for
government subsidies.


Compressed Air Storage
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NDPOWER By C.A.R.E

One
O possible solution t thi energy storage problem i th use
ibl l ti to this t bl is the
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of compressed air. When the wind blows during the night (when
electricity demand is low), the electricity generated can be used
to power an air compressor The compressed air can then be
compressor.
WIN

stored in the underground caves and caverns left from some
forms of mining. During the day when demand peaks (and
wholesale electricity prices peak) the compressed air can be
released through a turbine generating electricity. These caverns
will effectively provide battery storage for wind power.
The overall efficiency of this system can be as much as 75% 75%.
Although 25%+ of the wind generated electricity is lost, the
remaining 75% is used at peak times thus reducing the number
of conventional power stations needed to meet demand
demand.
Dakota, the windiest state of the USA, Sirius Exploration plan to create eight 16m (diameter) x
160m caverns (by potash mining) which will be able to power a 100MW turbine when filled with
compressed air. A similar projet is being developed in Ireland by Gaelectric with a cavern large
enough for at least a 136MW turbine.
g 3


Compressed Air Energy Storage
(CAES)
NDPOWER By C.A.R.E

Although a compressed air energy storage (CAES) system has not
R

been tested commercially with wind turbines, a 290MW plant
in Huntdorf, Germany has been running successfully for over 25
years storing excess production from a conventional power station
WIN

so it can be sold at times of peak demand. Compressed air is stored
in engineered salt caverns, and when released can generated
sufficient electricity to meet the needs of almost 300,000 homes. A
y 3 ,
second commericial unit was built in 1991 in
McIntosh,Alabama with a 110MW turbine.
Other (conventional) sources of electricity could be stored in the
( ) y
same way further reducing the number of conventional power
stations required to meet peak demand is reduced. The Future for
CAES and Wind Power As more wind farms are constructed, and
our ddependence on the electricity they generate i
d h l i i h increases, energy
storage is going to become more and more important. In North


Pumped Hydro –
An Alternative Technolog
Alternati e Technology
NDPOWER By C.A.R.E

The other main alternati e to
alternative
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compressed air energy storage
is pumped hydro - a very
well established technology in
WIN

which electricity generated at
times of low demand is used to
pump water from a low lake to
a high lake. At times of peak
electricity demand the water in
the upper lake is released down
pp
through a turbine. Pictured
above is the Sloy Power
Station which uses pumped
hydro technology ( d was
h d h l (and
constructed many decades ago


Pumped Hydro –
An Alternative Technology
NDPOWER By C.A.R.E
WIN R


centre for application of renewable energy
WEBSITE : http://www windpower co nr http://www careindia co nr
http://www.windpower.co.nr http://www.careindia.co.nr
EMAIL : care.india@live.co.uk windpower@live.co.uk

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