Did you know wind energy was a form of solar energy? Well, now
you do! Wind is the motion of air that results from the sun’s unequal heating
of Earth’s surface. In other words, wind energy and the breeze we feel is what
becomes of air that travels from the hotter portions of Earth’s surface into
the colder regions.
These
currents of air are what people ‘harvest’ by the use of wind turbines to
produce wind energy or wind power.
To
put ‘harvesting’ wind into simpler terms, a wind turbine converts kinetic
energy of the wind into mechanical energy. This mechanical energy is then
converted to electrical power with the help of a generator. It is then ready
for distribution as this electric energy produced from wind goes through
transformers and into appliance or equipment circuits.
Mechanical
energy produced by the wind turbine doesn’t always need to be converted to
electrical energy. It can be immediately utilized in specific tasks such as
water pumping in farms.
Wind
energy is a pretty neat power source. But there are a number of things to
consider about it. It has its advantages and challenges as well as
considerations when putting up a wind farm. But with the right circumstances, a
wind farm may be able to provide as much as 1000MW to 5000MW of power.
Advantages of Wind Energy
1.
Renewable
There
is no problem in harvesting wind continuously. Unlike its fossil fuel
counterparts that run out, wind will have pretty much the same supply of
resource in the future as it does now.
Wind
power farms are known to generate between 17 and 39 times as much power as they
consume, compared to 16 times for nuclear plants and 11 times for coal plants.
2.
Non-polluting
Wind
energy produces non-polluting electricity. Unlike conventional power plants,
wind farms emit little or no air pollutants and greenhouse gases.
In 2014, wind power avoided over
608 million tonnes of CO2 emissions
globally. The number of CO2 emissions avoided further increased in 2016 with 637 million tonnes of avoided emissions.
3.
Lower lifetime expenses
Building a wind farm requires a
huge initial investment mostly
on its machinery and installation. But throughout its lifetime, it costs less than conventional power
plants which still includes fuel and operating costs.
Fluctuating fuel costs have no
impact on wind power generation costs. It also operates in relatively minimal
expenses. According to Lazard,
wind costs have fallen 66% since 2009, from $140/MWh to $47/MWh.
4.
Flexibility to demand
Wind
energy projects are flexible with regard to an increasing energy demand. When
demands increase, single turbines can easily be added to an existing wind farm.
Disadvantages and Challenges of wind energy
1.
Noise
Each
turbine can generate the same level of noise as a family car travelling at 70
mph. More of the wind is converted in rotational torque and some of it, into
acoustic noise.
Most
of the turbine noise is masked by the sound of the wind itself, and the
turbines run only when the wind blows. In recent years, engineers have made
design changes to reduce the noise from wind turbines. Early model
turbines are generally noisier than most new and larger models.
Additionally, proper
siting and insulating materials can be used to minimize noise
impacts.
2.
Avian/ Bat Mortality
Bird
and bat deaths are one of the most controversial biological issues related
to wind turbines.
Although
several large wind facilities have operated for years with only minor impacts
on these animals, the deaths of birds and bats at wind farm sites have still
raised concerns from fish and wildlife agencies and conservation groups.
Careful
site selection is needed to minimize fatalities and in some cases
additional research may be needed to address bird and bat impact issues.
3.
Intermittent energy production
Many
critics often cite the fact that technologies like wind turbines only produce
energy when the wind is blowing. The production of each turbine is dependent
whether the wind is blowing hard enough.
It is challenging because intermittent production disrupts
conventional methods for planning the daily operation of the electrical grid.
4.
Disfigures scenery
Large
wind turbines are unsightly structures and not pleasant or interesting to look
at. They disfigure the countryside and are generally ugly.
Even
though it’s nice to place wind turbines aesthetically, efficient placing is
still priority. Wind turbines are placed where harvesting wind is greatly
optimized.
5.
High initial investment and large land area used
Initial
investment in building a wind farm is high. Approximately 75% of the total cost
of a wind farm is related to upfront costs such as the cost of the turbine,
foundation, electrical equipment, grid-connection and so on.
In regards to the land required,
not all the land in a wind farm is used. Wind turbines must be spaced approximately 5
to 10 rotor diameters apart, so that they may operate more
efficiently and lessen turbulence created by neighboring turbines and
obstructions. An 80-meter (262-foot) rotor would need to be about 560 meters —
more than a third of a mile — from adjacent turbines.
A
rule of thumb is to install a wind turbine 150 meters away from any nearby
obstruction, and at a height such that the bottom of the rotor blades will be 9
meters (29.5 feet) above the obstructions, including buildings and trees.
Wind farms aren’t concentrated
in land. In fact, offshore wind farms exist.
London Array is the largest offshore wind farm located in the outer Thames
Estuary more than 20km off the coasts of Kent and Essex.
There
are many other concerns for wind energy. But with proper siting and planning,
these concerns are outweighed by the advantages it brings. More and more people
have been investing in wind and solar technologies in producing electricity.
Around 2014, wind energy supplies 3% of global electricity. That number
increased to 3.7% in 2015.
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