Wind turbines capture kinetic energy from the wind to generate electricity. A modern wind turbine consists of over 20 components including blades, a rotor hub, generators, and a tower. The electricity generated is sent through transmission systems involving substations and power lines to distribute power to homes. While early wind turbines powered individual structures, grid-connected turbines now feed large amounts of renewable energy into electrical networks. The wind power industry has grown substantially since the 1970s but also experienced periods of decline, though new technologies have allowed for increased efficiencies and applications even in low-wind areas. Projections estimate that global wind capacity could reach 1600GW by 2050 to help transition to renewable energy sources.

1. JuanMoreno
12/02/2015
Wind energy describes the process by which mechanical power or electricity is generated
by the use of wind. Wind turbines capture and convert the kinetic energy in the wind into
mechanical power which can then be converted into electricity by a generator. There are various
types and sizes of wind turbines however, all wind turbines function to produce clean power
from an abundant resource.
A modern wind turbine consists of twenty different components that include blades, rotor
hub, blade pitch drive, main bearing, yaw drives, low speed shaft, parking break, gearbox, high-
speed shaft, electrical generator, nacelle, base frame, 3-cup anemometer, wind vane, sonic
anemometer, lightning protection, yaw gear, tower, foundation, and the padmount transformer
which is usually located at the base of the tower. The blade, rotor hub, and the pitch drive are all
interconnected and work together to capture the maximum energy possible by allowing
adjustment to the fiberglass blades depending on wind speeds. The yaw drives are located at the
top of the tower and serve the purpose of keeping the turbine aligned. Above the yaw lines and
connected to the rotor hub is the low speed shaft. The low speed shaft uses the gearbox and a
high speed shaft to transfer higher revolutions per minute to the electrical generator. Some
turbines use permanent magnets and direct drive generators so that it eliminates the need of a
gearbox. All of these components are housed by the nacelle and rest on the base frame of the
wind turbine. On top of the nacelle is the anemometer, wind vane, sonic anemometer, and
lightning protector. The anemometer is used to measure wind speed, the wind vane is used to
measure wind direction, and the sonic anemometer is used to measure wind velocity. The base
frame is set on top of the yaw gears which allow for the turbine to be aligned with the current
wind direction. Under the yaw gear is the tower and finally, the foundation of the turbine.

2. JuanMoreno
12/02/2015
Getting electricity from a wind turbine farm to one’s house is a difficult and tedious
process. Before electricity reaches a person’s home, it goes through transmission substations,
high voltage transmission lines, substations, distribution lines, and transformers. First, the energy
is created by the wind passing through the blades which function much like airplane wings,
generating lift-and-drag forces due to pressure differences on the surface. Once the turbine is
properly aligned with the direction of the wind, the turbine blades begin to turn, causing the shaft
inside the turbine to turn as well. The rotating shaft is tied into a generator that turns mechanical
energy into electrical energy which is then passed on to a padmount transformer. The padmount
transformer is used to increase the voltage coming from the generator to the higher voltage,
which is then used for the collection system. The power from the turbines is then sent to an
electric substation where transformers convert energy to the voltage of the transmission lines.
High voltage transmission lines then transport generator produced electricity to substations.
Substations have various purposes. One purpose of a substation is to connect generators,
transmission, or distribution lines to each other. A second purpose, is the transformation of
power from one voltage level to another. Another purpose of a substation is to control the system
voltage and power flow. Lastly, a substation can also work as an isolator of sections of an
electric line that may be experiencing overloads or faults. After the substation, the power is then
distributed to the transformer behind a person’s house by the use of distribution lines.
The first wind driven generator in the United States was installed in the late 1800s by
Charles Bush in Ohio. This generator was built out of wood and had a direct current generator
connected to a series of batteries which was used to power his house. Decades later, in the 1920s
and 1930s, companies began to produce wind generators to charge batteries and power lights and
radios for locations. In 1942, the first grid connected turbine was installed and designed by

3. JuanMoreno
12/02/2015
Palmer Putnam. Putnam’s turbine only operated for a couple of years until the metal blade flew
off. The turbine was never repaired as all the money went towards World War II during this
time. Once the war was over, the price of oil and other fossil fuels declined. Access to the fuels
was readily available and the idea of using wind power to produce energy was forgotten. It was
not until the oil embargo of 1970 that the United States began to rethink the dependence of fossil
fuels and as a result, the Department of Energy was created. With the Department of Energy in
place, the first wind farm was constructed in California, making it the leading state in wind
turbine installations in the 1980s. The equipment being installed in California was not very
reliable and mostly inefficient despite being the leading state in wind turbine installations during
that time. It was not until the 1990s that people began to show support for renewable energy and
implemented Renewable Portfolio Standards, which mandated that a certain fraction of electrical
energy be produced from wind power or other types of renewable resources. Between 1988 and
2000, installed wind power capacity was minimal. It was not until 2001 that wind energy began
to grow rapidly. In 2010, wind energy slowed due to a global recession. In 2011 and 2012, the
United States wind industry rebounded however, it was then quickly followed by another steep
decline in 2013 due to the failure of Congress to extend the production tax credit. Despite many
ups and downs, the wind industry will continue to grow and continue to design turbines. Since
1995, wind turbines have increased in size and power output. The biggest turbine designed in the
1990s was a Kenetech wind turbine that measured 33m rotor and produced 365kw. Currently,
there is a turbine designed Enercon with a 126m rotor and a 7MW output, making it one of the
biggest wind turbines.
It is estimated that by the year 2050, global wind capacity will be at 1600GW based on
model projections. At the end of 2012, installed wind capacity in the world was 282,482MW,

4. JuanMoreno
12/02/2015
with Europe in the lead having 38.7%, Asia having 34.6%, North America having only 23.9%,
Latin America having 1.2%, Australia having 1.1%, and Africa with 0.4%. If the world is to be
powered by renewable resources, having an aggressive renewable energy plan is vital and must
be implemented. With the presidential election nearing, only two of the candidates have a
renewable energy plan however, that plan focuses more on solar energy instead of wind.
Wind power has been used for centuries beginning with windmills, which are the
predecessors for the modern wind turbines seen today. While the turbines today are much more
complicated and intricate than its predecessors, the principles remain the same. There are
numerous benefits for the use of wind turbines which are not limited to being cost competitive
with fuel sources, creating manufacturing, installation, and maintenance jobs, and being an
abundant and renewable resource that does not deplete natural resources. Due to improved
technologies, wind turbines can be used in areas with low wind speeds and can also be used
offshore. “As the wind energy industry continues to grow, offshore development has the
potential to significantly boost domestic renewable energy production” and help move America
toward energy independence (Office of Energy Efficiency & Renewable Energy).

5. JuanMoreno
12/02/2015
(Office of Energy Efficiency & Renewable Energy). Web energy.gov
Wind Energy Essentials.New Jersey: John Wiley & Sons Inc 2015