WIND POWER
This is about the power of wind energy, the one used to produce electric energy (that is, the energy that we use at home).
It can be transformed into two other types of useful
energy, such as mechanical and electrical.
It is one of the oldest known forms of energy, together
with thermal power.
It has its origin in the sun.
Only a 2 per cent of the energy that the Earth
receives becomes wind power.
Is a kind of renewable energy.
Is the current largest global consumption in the world.
HISTORY
Wind power grew in the XX century
Its uses were to:
-get water
-move boats
-grind wheat
-produce mechanic energy
The first windmills were made in Sistan, Afghanistan
in the VII century, with a vertical axis with rectangular pieces (with 6 or 8
blades), used to grind wheat and bring water up.
The first windmills were made in France and some other
European countries.
They were made of wood and moved manually to
pull up the blades towards the wind.
Pumping mills:
- Very important in United States
-They were used for the Railroad Expansion
Modern turbines:
-They expanded in 1980
HOW IT WORKS
The aim of wind power is to transform wind into other types of more useful energy. In order to do it, we use wind turbines, which are big structures of about forty to fifty metres high on the top of mountains or high places.
Wind turbines are the evolution of old mills and they
are high technological mechanisms. Most of these turbines generate
electricity since the wind reaches a speed between 3 and 4 metres per second,
and they disconnect to prevent damage when the wind exceeds fifteen metres per
second.
Wind turbines are grouped into wind farms, and they
can be on land or sea. But wind farms on land are the most common ones.
The main parts of a wind turbine are.
1. Rotor: blades of 23 metres and the
rotor, joined to the axis. If wind has enough strength, it starts to rotate.
2. Main axis: the movement of the rotor is
transmitted to this axis, which sends its speed to the multiplier
3. Orientation engine: it rotates the gondola
(that is, the box which protects the internal mechanism), so that the rotor is
wind oriented.
4. Yaw drive: the orientation engine which fits
the gears and produces the movement of the gondola
5. Controller: it orients the gondola and
indicates the rotor to rotate when there is wind
6. Gearbox: the rotor turns at about 22
revolutions per minute. So the multiplier converts this number of lapses into
1500 revolutions per minute
7. Minor axis: carries the power from the
gearbox to the generator
8. Mechanic brake: makes sure the rotor doesn’t
turn while maintenance works are being carried out.
9. Generator: it produces energy when it turns
on. The current is sent by cables.
These parts form a simple process: wind passes to the
blades of the turbine and the rotor captures the movement. The blades spin a
shaft that is inside the gondola and which communicates with the gearbox. This
increases the speed of the shaft and activates the generator, which transforms
the rotational energy into electric energy.
TYPES
Wind turbines can be classified according to two characteristics:
A) Types of axes:
a) Horizontal-axis: they are the most common.
Their main characteristic is that the axis of rotation is parallel to the
ground and to the wind direction. They are more expensive than the vertical
ones and their blades don’t bear high speed, the advantage is that they are
more efficient than the others.
b) Vertical-axis: they are not the most common
because of their low capacity to produce energy. Their main characteristic is
that their axis of rotation is perpendicular to the ground. They are cheaper
because they save much of the infrastructure. They have advantages and
disadvantages. Among the advantages, they don’t need a tower, so the
installation and maintenance is easier and there is no orientation mechanism.
And their disadvantages are: being near the ground, the wind speed is low, in
fact they have low efficiency. They aren’t auto started, they need a manual
form of starting plus tensioning cables.
B) According to the wind.
a) Windward: they are the most common turbines. Their
main characteristic is to place the rotor facing the wind, preventing this way,
the tower to intervene between the very rotor and the wind direction.
b) Leeward: this type of orientation is used in
vertical-axes turbines. Their main advantage is that they don’t need the
orientation mechanism of the gondola, and they have the disadvantage of a low efficiency.
ENVIRONMENTAL IMPACT
Today, we are reaching the limits of the capacity of ecosystems to regenerate the pollution caused by humankind. One third of the total global pollution generated comes from the electricity production processes. The development of renewable energy sources is desirable and necessary. Wind is a natural source of energy, renewable and non-polluting.
The generation of
electricity from wind doesn’t produce toxic gases, or contribute to the
greenhouse effect or acid rain. It doesn’t produce any harmful products as
radiation or radioactive waste. Each kWh of electricity generated by wind power
instead of coal, avoids the emission of approximately one kilogram of carbon
dioxide into the atmosphere.
In one year of operation,
a wind turbine produces more energy than was used in its construction. The
consequences of wind energy have localized and reversible effects, which
can be overcome by technical solutions, unlike traditional energy sources, whose impacts are often
general, permanent and costly disposal.
The possible effects of a
wind project on the environment must be analyzed with the completion of an
environmental impact study. In principle, protected natural areas should be
excluded from the development of wind energy.
The impact of an activity
on the environment has a greater or lesser effect depending on three main
factors: the nature of the action itself, the ecological fragility of the area
where you have to take out the action and the ecological quality of the venue
of the project.
COST
Nowadays, new energies are being born.
One of the best-know ones
is wind power. In Spain, we have developed it in many areas such as Navarra and our region, Castilla-La Mancha.
The cost of wind energy
can be analyzed according to different points of view:
A. private cost
B. operating cost
C. socio-economic
D. social costs
E. energy saving
Then, let’s try to
explain the energy saved thanks to this new energy and some of its socio-economic benefits.
They include: staff cost,
operating and maintenance.
C. Social cost
We can find three
important characteristics: job creation, energy saving and environmental benefits.
D. Energy saving
The following graph shows
how the annual energy production varies according to the wind strength of the
place and the height of the hub.
The numbers of annual
energy production assume that wind turbines are in service all the time.
E. Socio-economic
There are a number of
effects produced by wind power in the rest of the economy and society. The
benefits of wind power have not yet been economically valued.
THE WORLD´S MAIN SOURCES OF WIND POWER
Europe
Germany has the largest
number of wind farms in the world and the largest wind turbine built on the
sea, and Scotland will have Whitelee Wind Farm, the
second in Europe, with 140 wind turbines of 2.3 MW each one, a total
installed capacity of 322 MW.
Spain has, as of late
2011, 259 MW of installed wind power, which accounts for 16% of the whole
demand.
Castilla y León is the
region with a higher installed capacity (4,540 MW in 2011).
Chipiona hosts one
of the largest offshore wind farms in Europe, a so-called offshore. An offshore
wind farm consists of a series (even hundreds) of wind turbines mounted on vertical
structures anchored to the seabed. It is precisely the fixing process on the
background (and unpinned at the time) that generates greater noise impact on
the marine environment. The latest engineering research says that the final
solution to the impact of noise on humans and marine life, and visual impact,
will come from floating turbines. However, these structures are, up to now,
enormously expensive to manufacture, maintain and upkeep, and only a very high
price of energy could justify solutions of this kind.
Mexico
Mexico is the largest
wind farm in Latin America, located in the Isthmus of Tehuantepec, in a town
called La Venta. It was built by Mexican cement company Cemex, with the support
of the Federal Electricity Commission CFE.El.
On March 14, 2012, the
wind farm Arriaga, the first of its kind in the state of Chiapas, opened with
16 wind turbines.
Total capacity of
installed wind power
|
||||||
Capacity (MW)
|
||||||
Position
|
Country
|
20099
|
200810
|
200611
|
2005
|
2004
|
1
|
USA
|
32.919
|
25.170
|
11.603
|
9.149
|
6.725
|
2
|
Germany
|
25.030
|
23.903
|
20.622
|
18.428
|
16.628
|
3
|
China
|
20.000
|
12.210
|
2.405
|
1.260
|
764
|
4
|
(13%)
18.26312
|
16.754
|
11.730
|
10.028
|
8.504
|
|
5
|
India
|
10.742
|
9.654
|
6.270
|
4.430
|
3.000
|
6
|
France
|
4.655
|
3.404
|
1.567
|
757
|
386
|
7
|
Italy
|
4.547
|
3.736
|
2.123
|
1.717
|
1.265
|
8
|
UK
|
4.015
|
3.241
|
1.963
|
1.353
|
888
|
9
|
Denmark
|
(20%)
3.384
|
3.180
|
3.136
|
3.128
|
3.124
|
10
|
Portugal
|
(15%)
3.374
|
2.862
|
1.716
|
1.022
|
522
|
ADVANTAGES
1.
Wind is free and can
be captured efficiently with modern technology.
2. Once the
wind turbine is built, the energy that it produces does not cause green house
gases or any other type of pollution.
3. Wind farms are built on land that
is not used for anything else.
4. The
electricity produced in these wind farms is used in the areas next to them,
because the city is so far.
5. This energy
is cheaper than others.
6. It is a
clean energy (that does not pollute) and is renewable, it means that it never
finishes.
7. A 30% of
total energy consumption in Spain comes from wind power.
DISADVANTAGES
1.
Wind is not constant, some days a lot of wind
energy may be produced, but some other days we no energy can be produced
because of the lack of wind.
2. Wind farms
which are in the countryside destroy the views and nature.
3. This energy
is one of the noisiest ones because of the wind turbines. And this noise can be
heard many km away.
4. It can also
be in the middle of migratory routes of birds, so the animals are seriously
affected by it.
