New Directions for Wind Turbines

Engineering Conceptual Design Project
Spring 2014
New Directions for Wind Turbines
Professor Weinschenk, WTSN 104, Section 54
Engineering Communications II
Wind Turbine Team
Jacob Groezinger Clay Mangette
Michael Zapata Mackenzie Ficker
Daniel Thornton Cyrus Vakili
Martin Pelic Benjamin Lai
May 9, 2014

1
Executive Summary
Background and Objectives:
Wind power has become a prominent form of renewable energy in recent years. However, due to
economic reasons, its use is not very widespread compared to that of fossil fuels. Our group was
given the task to correct this problem by focusing on the horizontal axis of the wind turbine and
modifying it to allow it to rotate about its horizontal axis. The design required that the nacelle of
the wind turbine was able to change its position, the power output of the wind turbine could be
maximized, and that if possible, a deterrent system could be installed to prevent unnecessary bird
fatalities.
Methods:
To gain a better understanding of the problem, the team dispersed to conduct research. The
topics for research included turbine function, weather effects on turbines, avian behavior
patterns, geographical location of wind turbines, and the materials used to construct wind
turbines. Afterwards, the team generated multiple solutions and chose the following alternative
designs:
- Causing the nacelle to rotate using electromagnets and manipulating the magnetic fields
generated from them
- Using a hydraulic rotary actuator to rotate the nacelle by converting fluid motion to
mechanical rotational motion
- Using a Ring and Pinion gear system controlled by electrical motors to rotate the nacelle
- Creating a gear system similar to that used in an oscillatory system in a household fan.
These solutions were then evaluated using a Paul and Beitz Matrix (see pg. 13). The solutions
were evaluated based off of the criteria of cost, the effectiveness of the control system, ease of
maintenance, its user/wildlife friendliness, environmental impact, and durability. The
justifications for these criteria and their weighted values can be seen on page.
Results and Recommendations:
The group agreed that the best possible solution is the Ring and Pinion gear system. As
previously stated, electrical motors are used to drive the pinions forward, causing the ring gear to
rotate the nacelle. The electrical motors are controlled by a modified Maximum Power Point
Tracking (MPPT) Circuit, which determines the location that will give the maximum power
output. This solution provides a relatively cheap, efficient, and environmentally friendly
alternative that will significantly increase the power output of a wind turbine.

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Table of Contents
Executive Summary 1
Introduction 3
Background 5
Final Problem Solution 7
Appendix I 9
Alternative Solutions 9
Alternative Solution 1 9
Appendix II 13
Paul and Beitz Evaluation Matrix 13
Appendix III 14
Criteria Justification 14
Appendix IV 15
Requirements Document 15
Requirements/Verifications 15
Figure 1 22
Figure 2 23
Appendix V 24
Final Project Solution Team Plan 24
Appendix VI 25
Research Paper 25
Research Paper 1 25
Research Paper 2 51
References 81
Sources Consulted 82
Image References 86

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Introduction
Purpose:
Fossil fuels cannot fulfill the world’s energy needs, so alternative forms of energy will be
needed. Wind energy, although viable, is not the most effective form of power generation due to
its cost of maintenance and small output compared to other forms of energy. Our team addressed
this problem by developing a conceptual design for a mechanism that would modify the
horizontal axis of a wind turbine to optimize power output. A solution was reached through a
process of research, defining requirements, brainstorming, and evaluation until a final solution
was agreed upon.
Task:
The team was asked to design a mechanism to modify the horizontal axis of a wind turbine. This
mechanism needs to increase the power output and, if possible, reduce the number of bird
fatalities caused by wind turbines. The
first step in finding a solution was to
research information about wind turbines
and existing systems to gain a better
understanding of the problem.
Considerable research was also done on
the patterns of bird populations. From
there, the group brainstormed multiple
alternative solutions and limited them to
four viable solutions that would
determine how the mechanism would
move the horizontal axis. These viable
solutions include
- Electromagnetics
- Hydraulics
- Fan oscillator
- Ring and Pinion system
It was agreed that all of these solutions
would have a common control system. A
maximum power point tracker (MPPT)
circuit would be included in all of the
solutions that would control the mechanism and direct the horizontal axis in the direction with
the highest wind density. The generated solutions concern the different means of powering the
mechanism.
Solution:
The team then broke off into groups of two and each pair researched their respective solution.
Each pair then presented their findings to the rest of the group. Each solution was evaluated
using a Pahl and Beitz Matrix based on of the criteria of cost, ease of maintenance, lifespan,
environmental impact, safety, and its implementation of the control system. With relatively low
cost of maintenance and long life span, the ring and pinion system was considered the most
viable option. One reason for this was because the group agreed that the cost would be the lowest

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on this solution. The modification adds a few simple moving gears made up of high strength
materials. It also received a high score for the control system requirement. Like the other
solutions, the ring and pinion system uses a modified version of the Maximum Power Point
Tracker (MPPT) Circuit. This circuit uses information from its surroundings to calculate the
power output at each position and determine where the maximum power point is located. The
Ring and Pinion system’s parts are all simple gears, and the group reasoned that the simplicity
would minimize maintenance costs.
Conclusion:
The ring and pinion system satisfies all of the requirements for the project. The design contains a
control system that can track the maximum power point and will increase the power output of the
turbine significantly. The ring and pinion system also has the advantage of requiring very little
maintenance because of its use of high strength materials. In case of emergency, a manual shut
off system is in place to increase the safety of the system. The overall cost of the system should
theoretically be very low because of the simplicity of the system and its ability to be integrated
into existing wind turbine designs.
This report is a representation of the process that our group used to generate, design, modify, and
chose a final solution to the problem. Through the process of verification, we will prove that the
ring and pinion system is the best solution to modifying a wind turbine’s horizontal axis. Our
team believes that our solution is the most efficient, environmentally friendly, and cheapest
option and hope that the project CEO will agree.

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Background
Introduction:
As of right now, wind turbines account for only 3% of the energy generated in the United States.
This percentage is nowhere near what the US Department of Energy estimates can be generated
by the existing number of turbines throughout the country. The estimated amount of energy that
can be produced from existing wind turbines is at about 20% (DOE, 2012). Our solution allows
the wind turbines to rotate on a horizontal axis, so that they can work no matter what direction
the wind is blowing at that given time. This would allow percentage of energy that wind turbines
produce to rise dramatically. Wind power is one of the most economical sources of renewable
electricity, and in some cases the same cost per kilowatt hour as non-renewable resources, at
approximately 5 cents per kilowatt hour.
How Wind Turbines Work:
Wind turbines are a very simple way of generating cheap electricity for a large amount of the
US. Turbines are the most effective when placed in areas that have consistent winds going
through the area, between a range of 8 and 55 mph (DOE, 2012). These winds turn three blades,
which are similar to propellers, around a
rotor. This rotor is connected to a shaft
that spins a generator, which produces
the electricity. This is the nacelle of the
wind turbine, which is the part that
would spin on its horizontal axis to
catch more of the wind. A tower is
connected to the nacelle, typically
around 100 feet or more in the air, to
catch the most wind possible. Winds
typically at this height are faster and less
turbulent. At this height, the turbine is
able to work more efficiently.
Turbines come in different sizes, from small ones that can power single homes, to industrial
turbines that are typically placed in “farms,” or groups of turbines, that are capable of powering
thousands of homes and businesses. These industrial wind farms are typically placed in rural
areas so as not to disturb families and businesses, but must be placed within a reasonable
distance so that the power can be transported to power substations, and then to wherever it needs
to go. Wind turbines can range in size from about 50 kilowatts all the way to five Megawatts.
The size of the wind turbine typically determines what it powers. Smaller turbines typically do
things such as pump water, while larger turbines are used by industrial companies to supply
power to homes and businesses.

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Project
Breakd
own:
Our
project
has
been
broken
down
into
many key components that our group feels are necessary. The first thing that needs to be done is
adequate research to understand what technologies exist along with possible designs. Second,
our group must brainstorm possible solutions that will be evaluated on how well they comply
with our project requirements and project criteria. The efficiency of the wind turbine is the most
important criteria to our project and that is what should be focused on the most. Finally, the
costs of the modification should be considered because the costs of the implementation and
materials are going to be increasing the costs of the turbine as a whole. Following these
considerations and methods, the best possible solution to the problem statement will be generated
from the team as a whole.
Concluding Remarks:
In conclusion, all ideas that are brainstormed are to be taken into complete consideration, when
evaluated. If our team is to come up with a feasible and pursuable option, then wind turbines
across the world will be improved and the percentage of energy generated from wind turbines
will increase worldwide. With this solution, wind energy will be able to supply power to many
homes and businesses in America, which will not eliminate the need for fossil fuels at this time,
but will put a large dent in the usage of these sources of fuel. There is no reason why more
research should not be done with wind power, because it costs about five cents per kilowatt hour,
depending on the placement of the wind turbine. This is comparable to the cost per kilowatt hour
of coal or oil, however neither of these are a renewable source of energy, and are also harmful to
the environment.

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Problem Solution
Introduction:
The purpose of this modification was to create a system to rotate the nacelle and blades of a
horizontal axis wind turbine. For potential solutions to this problem our team looked for ideas
and solutions in not only the wind turbine industry, but also other industries as well. In our
research we discovered a potential design that fit our requirements that had been used everything
from the household pencil sharpener to car differentials. In order to satisfy our requirements our
solution had to be autonomously controlled, rotate the wind turbine a full 360 degrees, and be
efficient enough so that it did not take away power from the wind turbine itself. A ring and
pinion gear system seemed to be the best fit for this task.
Description:
The ring and pinion gear solution consists of three main components; the ring gear, the pinion
gears and the electric motors. The ring gear is located in the very top of the tower of the wind
turbine and will interlock with the four pinions which
are attached to the bottom of the nacelle. This will
provide a full rotation of 360 degrees around the yaw
axis. The system will utilize four electric motors which
will be mounted internally in the nacelle and attach to
the pinions on the bottom of the nacelle. The control
system of this solution will utilize a modified version of
a Maximum Power Point Tracker (MPPT), which will
be used to locate the angle at which the wind produces
the most force and automatically rotate the nacelle and
blades to face that angle. In addition to this the control
system will automatically start up the blades of the
wind turbine at a minimum speed of eight miles per
hour, conversely the control system will also automatically shut off the blades when wind speeds
exceed fifty five miles per hour. A bird deterrent system is also used in addition to our solution,
which emits an ultrasonic frequency of 22 kilohertz to deter avian species from entering the air
space that the wind turbine takes up. This frequency has been proven before to deter birds from
areas and will reduce the amount of avian fatalities caused by the wind turbine.
Analysis:
Our team believes that the use of existing technologies should be used rather than reinventing the
wheel when it comes to our solution. The ring gear and pinion gear system has been used
successfully in other applications such as the automotive industry. When properly maintained the
ring and pinion gears have been proven to last for a considerable amount of time. Electric motors
have been improving rapidly throughout the past years and have been implemented in other
devices. The motors will be the part of the solution that will need to be serviced the most often,
however the service schedule can be synced to the normal maintenance schedule of the rest of
the wind turbine. By using solar panels to power the electric motors and control system, the
modification will not need to draw power from the generator used in the wind turbine. This will
increase the efficiency of the overall system and will add another element to make the system
more environmentally friendly. The MPPT will be able to analyze data and make the necessary

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corrections to the yaw angle of the wind turbine. This will be done automatically and will also
provide the ability to rotate faster and more efficiently to maximize the amount of power that can
be harvested.
Conclusion:
Because this system solves the problem of rotating the horizontal axis while minimizing the
overall cost and maintenance needed to implement it, our team decided to use the ring and pinion
gear system as our final solution. The system meets our requirements that it be autonomously
controlled, rotate the nacelle 360 degrees and also deter avian species, so it was agreed that the
ring and pion system was the best possible solution.

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Alternative Solution: Electromagnetics
Introduction:
Implementing an electromagnetic system for the wind turbine will be very useful as an
alternative solution to the problem statement because it will provide sufficient energy to the
system. The system will be a high-efficiency system due to the lack of friction between the
magnets, therefore the system will be as efficient as possible.
Description:
The mechanism will utilize sensors that determine wind direction and from there the sensors will
be able to send a signal to the motor that will rotate the nacelle. This motor will be powered by
electromagnets that repel each other creating the power. The repulsion from the magnets’
opposing poles will create a force that rotates the nacelle to the desired wind direction. The most
important criteria in our Pahl and Beitz Matrix is the efficiency of the motor. The efficiency of
the motor will be greatly improved from the current design because the electro magnets are
frictionless, therefore there is negligible friction. Also, lifespan is an important piece of criteria
for our modification and the electro magnets will have a long lifespan because there is no friction
effecting the surface of the magnets. This mechanism will not have any effect on any outside
populations such as the birds because the mechanism is just rotating the nacelle and not causing
an increase in deaths to the neighboring bird population. The cost of the mechanism is higher
than the current model because the electromagnets are expensive, but the addition of the
electromagnets will allow the wind turbine to have a more compact design while maximizing the
electrical output.
Analysis:
The mechanism will utilize sensors that determine wind direction and from there they will be
able to send a signal to the system that will push the nacelle along the track. The sensor will be
able to detect wind speed and direction in order to rotate to the correct direction. A signal will
then flip a switch that will turn on a circuit that was implemented through the electromagnetic
system. This will cause the system to be put in motion along the track in order to rotate towards
the desired wind direction. The motor will be powered by electromagnets that repel each other
thus creating the power. The criteria that is most important to our project is the efficiency. The
efficiency of the motor will be greatly improved from the current design because the
electromagnets are frictionless; therefore there is negligible friction. Also, lifespan is an
important criterion for our modification and the electromagnets will have a long lifespan because
there is no friction affecting the surface of the magnets. This mechanism will not have any effect
on any outside populations such as the birds because the mechanism is just rotating the nacelle
and causing no further harm to birds.
Conclusion: The electromagnetic system was not chosen for the final solution. This was because
the group did not believe that the design’s compactness would compensate for the high cost of
the system. The group also questioned how much an electromagnet capable of moving a 27-90
ton mass would cost and whether such a magnet existed.

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Alterative Solution: Hydraulics
Introduction:
The modification will need to be able to provide enough torque to move the nacelle of the wind
turbine. One of the solutions that is proposed is to use hydraulic power to provide a necessary
rotational force. Hydraulics are known for being able to provide very high torques. This does
sacrifice speed, but the rate at which the wind turbine turns is no longer a constraint, so this
should have little impact on its viability.
Description:
A maximum power point tracking (MPPT) circuit will be used to measure the power being
generated by the turbine. If power generation is not optimized or the wind speed is below 8 mph
or above 55 mph, the circuit sends a signal that the horizontal axis needs to move. This algorithm
runs every thirty minutes to determine
whether the maximum power point has
changed in the given time. After the
maximum power point has been located,
an electrical signal is sent to an
electrically powered hydraulic rotary
actuator. This device is used to convert
translational motion into rotary motion.
This is accomplished by compressing and
expanding the fluid cylinder, which then
moves an elongated gear that rotates
another gear. The horizontal axis is then
turned in the optimal direction. The MPPT will stop sending a signal when it detects the
maximum power output available. To prevent permanent damage, the wind turbine will shut off
if the wind speeds around it are all greater than 55 mph. The control system will be powered
externally by a solar cell. In case of birds flying into the blades, an ultrasonic sound emitter will
be located on the nacelle.
Analysis:
This solution fulfills all of the criteria. Under optimal conditions, hydraulics have no negative
environmental effects because they produce no by-products. Although there is the risk of the
hydraulic fluid (oil) leaking, this can be prevented by properly maintaining the system.
Maintenance of the hydraulic pump is recommended to take place once every 1.36 years.
Conveniently, a wind turbine is shut down temporarily for maintenance once a year, so the
modification can be maintained at the same time (Vosburgh, 3). The control system is
autonomous, so there is no risk factor of injuring anyone. The ultrasonic pulse emitter has been
added to the design to keep local bird populations from running into the blades. According to
research conducted by the General Services Administration, many bird species will tend to avoid
regions that are polluted by ultrasonic waves of around 22,000 Hz (methods of bird control,
2012). This system will also increase the overall efficiency of the wind turbine. The MPPT
circuit will act as the control system and determine where the maximum power point is located
on a half hourly basis. As a result, the wind turbine will be exposed to higher wind speeds more
often, which increase the amount of energy generated over a period of time. In addition, the

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MPPT is powered by an external photovoltaic cell instead of the energy generated by the wind
turbine.
Conclusion:
The hydraulic rotary actuator fulfills many of the design requirements. The actuator provides a
strong enough torque to rotate the wind turbine at the desired speed. However, this design was
not chosen. Because the fluid being used by the actuator would most likely be oil, the group
determined this could become an environmental hazard in the event of a major failure. The oil
could leak from the system and damage nearby plant/wildlife. However, the algorithm for the
MPPT was used in the final solution as the control system for the ring and pinion system.

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Oscillating Fan System:
Introduction:
The use of an oscillating fan system is will be the best alternative solution due to the efficiency
increase of the wind turbine. This is due to the ease of access to gather the parts required, as well
as the small amount of energy that will be required to allow the wind turbine to move to the
desired position.
Description:
Our solution is very similar to an oscillating fan, which can turn a certain number of degrees
back and forth to spread air throughout a room. However, this solution would stop at a certain
point so that the wind turbine can get the maximum electrical output in any situation. This is
typically done by having a bar with a gear attached at the bottom drop so that it connects to a
second gear, which would allow the fan to rotate. This causes the fan to rotate a certain amount,
and the pause for a second before rotating back to its original position, and then an equal number
of degrees in the opposite direction. This is done by pushing a button on the fan, which pushes
the gear into place. When it comes to a wind turbine, there must be 360 degrees of oscillation, so
that the wind turbine can have the maximum electrical output at any wind direction. Also, this
would be completely autonomous, so that no human interaction is necessary except for
maintenance.
Analysis:
This solution satisfies many of the criteria of our project. The control system would be
autonomous, so there is no risk of human injury. Any loss in power from the control system
would be made up for by increase in the efficiency of the wind turbine. There would be no
increase in maintenance with this solution, except for the yearly maintenance that had already
been scheduled for each turbine. This solution would not have a significant contribution to the
amount of death in surrounding bird populations, since the system will not be in use the majority
of the time, specifically only when wind direction changes.
Conclusion:
Although this design fulfills many of the design requirements, it was decided that it was not the
most viable solution. The ring and pinion system had the advantage over the fan oscillatory
system due to its much simpler design.

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Pahl and Beitz Evaluation Matrix

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Explanation of Evaluation Criteria
Control System- The control system is an integral part of the design. The control system needs
to be able to operate autonomously and maximize the power output. We gave the control system
requirement a value of 0.25/1.00 because we believe it is the most important requirement of the
design.
Maintenance- The ease of maintenance deserves a weight of 0.15/1.00 because maintenance
costs money and time, reducing the overall worth of the wind turbine over the course of its
lifetime. The easier the turbine is to maintain, the more energy it can produce at a lower cost and
be a cost effective means of power production.
User/Wildlife Interaction- User/Wildlife Interaction deserves a value of 0.10/1.00 because the
wind turbine is in the environment for its entire lifespan. The wind turbine also should not
produce more bird deaths. Although this factor is important, it was given a lower value because
the group believed that the economic benefits of the mechanism were more important.
Environmental Effects- Environmental effects was assigned a value of 0.10/1.00 because
keeping environmental pollution to a minimum is a major concern to our group. We are trying to
clean up the generation of energy without hurting any other aspect of the environment.
Durability- Our group has assigned durability a value of 0.10/1.00 because durability is very
important to our group due to the high cost of installation of a turbine. The mechanism needs to
have a comparable lifespan to the wind turbine itself so that we don’t have to increase the cost of
maintenance.
Cost-We have assigned a value of 0.20/1.00 to cost because our modification can’t increase the
cost of the wind turbine to the point where the installation costs aren’t feasible. For a wind
turbine to be an economical alternative to fossil fuels, it needs be able to compete with them in
terms of power generation and cost of production.

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System Requirements/Verification
System Requirements (Higher Level)
[CHA 1.1] Requirement: The mechanism shall be able to vary the position of the
horizontal axis to maximize power output.
Verification: The mechanism utilizes a gear system to rotate the nacelle
and blades 360 degrees and will be faced in the direction of the wind.
[CHA 1.2] Requirement: The modification to the axis shall enable it to have at least
two degrees of freedom.
Verification: The modification will allow for an added degree of freedom,
by allowing the yaw angle of the nacelle to be controlled
[CHA 1.3] Requirement: There shall be a control system that will allow control of its
position.
Verification: The ring and pinion system will enable control over the
position of the wind turbine. The system is controlled by an MPPT control
system (see figure 1).
[CHA 1.4] Requirement: The modification shall track and follow the maximum
power point.
Verification: The maximum power point of the system will be tracked by a
technique called maximum power point tracking. The technique is a series
of connected inverters, solar chargers, to get the maximum power from
one or more devices (See figure 1).
[CHA 1.5] Requirement: The modification shall operate in inclement weather

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Verification: A de-icing system will be placed which works with an ice
detector that can be placed that can detect if an ice load becomes
critical. Hot water and helicopters will provide hot water sprayed onto the
blades, with no chemicals, to remove the ice (Gedda,2014)
[CHA 1.6] Requirement: The Wind Turbine shall minimize negative effects to the
environment.
Verification: The electric motors used to run the ring and pinion system
will be run by solar energy so the harmful waste of using fossil fuels will
be avoided
[CHA 1.7] Requirement: The CHA shall rotate the axis of a turbine with blades that
weigh between 27-90 tons.
Verification: The range of weight of the blades is based on a calculation
that were made for the minimum and maximum weight of a wind turbine
blade. Also accounted for was +/- 25% when it comes to the minimum
and maximum value allowed. Therefore, the system can support blades
with weights from 27-90 tons.
Minimum Weight:
(.25*30 tons = 7.5 tons)
34 tons - 7 tons = 27 tons (Minimum)
Maximum Weight:
(.25*72 tons = 18 tons)
72 tons + 18 tons = 90 tons (Maximum)

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Subsystem Requirements (Lower Level Subsystem)
[ENV 2.1] Requirement: The CHA shall have an increase in efficiency of at least 5%
as a result of the modification. {CHA 1.4}
Verification: The capacity factor of the wind turbines after a ring and
pinion system is placed in the nacelle will rise significantly and allow the
wind turbine to work more of the time. This will allow the turbines to
generate more power. {CHA 1.4}
[ENV 2.2] Requirement: The modification shall not create more than 43 decibels of
noise at a distance of 500 meters away from the wind turbine. {CHA 1.6}
Verification: A study shown done by Keith Longtin shows that the
average decibel level of wind turbines at 500 meters is less than the
background noise of the area. Our modification will be using sound pulses
at above the hearing range of humans (22 kilohertz) which will not
contribute to noise pollution (How much noise..?, 2014)
[UWI 2.1] Requirement: The modification should have a system that deters avian
species from the wind turbine. {CHA 1.6}
Verification: The system will produce a noise that deters birds from the
airspace around the wind turbine. This is accomplished using Ultrasonic
sound pulses that do not contribute to noise pollution (methods of bird
control, 2012). {CHA 1.6}
[UWI 2.2] Requirement: The CHA should not interfere with birds migration routes.
{CHA 1.6}

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Verification: The system will be located in a spot where bird migration is
proven to be rare. {CHA 1.6}
[UWI 2.3] Requirement: The CHA shall allow the turbine to provide enough power
for 350- 450 homes. {CHA 1.1}
Verification: A study that has been done has shown that a wind turbine
working with a 25% capacity factor can power approximately 350
homes. With this given solution the capacity factor will rise because the
amount of exposure of the turbine to high wind velocities will increase,
allowing the turbine to power more homes (Tradewind Energy,
2013). {CHA 1.1}
[MNT 2.1] Requirement: The CHA shall operate continuously without any
interruptions. {CHA 1.1, CHA 1.5}
Verification: The CHA is designed to operate continuously and is
regulated by the control system to prevent an unscheduled stop of the
system (see figure 1). {CHA 1.1, CHA 1.5}
[MNT 2.2] Requirement: The modification shall have an alert system that warns for
potential failures. {CHA 1.3}
Verification: The control system will monitor for future failures. Refer to
MATLAB demonstration
[MNT 2.3] Requirement: The system shall be internally contained in the nacelle
housing. {CHA 1.5}
Verification: The gear ratios for the ring and pinion can be arranged to
adjust the size of the system to fit in the nacelle. {CHA 1.5}

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[DUR 2.1] Requirement: CHA shall last at least twenty years, unless replaced due to
new technologies. {CHA 1.1}
Verification: The control system will be internally housed in the nacelle
and will be made from steel, which has a lifespan of over 20 years. The
electric motor system will need maintenance, but will last 20 years if
installed correctly. {CHA 1.1}
[DUR 2.2] Requirement: CHA shall not have to undergo maintenance more than once
in a calendar year. {CHA 1.1}
Verification: The intervals of maintenance for the CHA is equivalent to
the intervals of maintenance that the wind turbine as a whole requires,
which is once a year.
[DUR 2.3] Requirement: CHA shall not be made of a highly corrosive material.
{CHA 1.5}
Verification: The tower of the turbine shall be made of steel and the blades
will be constructed of fiberglass. ASTM-A36 structural steel is
recommended because of its high modulus of elasticity, 2.00E11 N/m^2.
Fiberglass has a lower modulus of 1.70E10 N/m^2, but will be sufficient
(Young’s Modulus, 2014).
[CNS 2.1] Requirement: The control system shall use electrical energy to control the
position of the horizontal axis. {CHA 1.3}
Verification: The control system is designed to draw power from the solar
panels mounted upon the nacelle of the wind turbine. {CHA 1.3}

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[CNS 2.2] Requirement: The control system shall not consume more power than
what is gained by the modification. {CHA 1.4}
Verification: The control system will use the external power created by the
solar panels. This will prevent the system from draining power from the
wind turbine itself. {CHA 1.4}
[CNS 2.3] Requirement: The control system shall be autonomous. {CHA 1.3}
Verification: The control system is an autonomous MPPT circuit. It
collects wind speeds using an anemometer, compiles them into a list,
calculates power, and makes a decision on the position of the horizontal
axis (See figure 1).
[CNS 2.4] Requirement: The control system shall be able to rotate the axis 360
degrees. {CHA 1.3}
Verification: See solid edge model. (Figure 2).
[CNS 2.5] Requirement: The control system shall start up the machine at wind speeds
of 8 mph and shut off the machine at wind speeds around 55 mph {CHA
1.3}
Verification: In the MATLAB simulation, an if statement is included so
that the wind speeds are out of range, the turbine will shut off (See Figure
1)
[CNS 2.6] Requirement: The control system shall allow the horizontal axis at a rate
of 5 degrees/sec {CHA 1.3}.
Verification:
ω = 5 degrees/sec = 0.085 radians/sec

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The mass of the nacelle can vary from 27 to 90 tons. 90 tons (82,000 kg)
will be used for calculations. The moment of inertia will be calculated by
modeling the nacelle as a large cylinder with a radius of 50 meters (the
radius of the blades used for larger scale turbines)
I=0.5MR2
, I =0.5(82,000 kg) (50 m)2
I=1.03e8 kg*m2
The Work needed to rotate this mass is equal to the change in kinetic
energy
W=K=0.5Iω2
W=0.5(1.03e8 kg*m2) (.085 rad/s)2
W=3.72e5 J
Having to expend this much energy to move the nacelle at the required
speed would result in a significant loss in power generated. This
requirement cannot be met.

23
Figure 2 – Solid Edge Models
The nacelle of the wind turbine was used from http://www.grabCAD.com/library/30kw-wind-
turbine/. The ring and pinion system below the nacelle was created by the team.
The ring and pinion gear system
allow the nacelle to rotate 360
degrees around axis

24
Final Project Solution Team Plan

25
To: Professor Weinschenk, WTSN 104, Section 54
From: Michael Zapata
Re: Research Paper #1
Problem Statement:
Develop a mechanism that would vary the position of horizontal axis wind turbines to maximize
electrical output in any wind conditions.
Introduction:
For years, countries have been trying to find an alternative source of energy to lower the use of
fossil fuels. One idea that to spread around the globe was the use of wind energy, involving wind
turbines. Wind turbines have great benefits such as producing energy efficiently while being
healthy to the environment. While the wind turbines seem like they cause no harm to anyone, the
wildlife around them, especially the birds and bats, are negatively affected causing not only
damage to the turbine themselves, but deaths to the wildlife population around it. This paper
addresses animal safety made possible by the wind turbines through the reasons for the avian
collisions while analyzing the concepts to prevent and reduce the number of deaths. The effect
that the wind turbines have on the wildlife is explained through the reasoning behind the deaths
of the animals. This paper also examines how the specific type of species a bird is can influence
their strategy on interacting with the wind turbines. If the wind turbines are positioned properly,
the deaths could be avoided along with producing the maximum amount of wind energy.
Birds and Bats negatively affected by Wind Turbines:
Wind turbines can have a negative impact on the environment involving birds and other wildlife
around the area where wind turbines are built. One concern is the collisions that birds have with
the wind turbines causing the most obvious of reasons that leads to the death of birds, but
additional research factors tell of other possible causes of death instead of collisions (Zittkowski,
2012). Researchers have discovered that the color of the wind turbines has a factor on the
alarming deaths involving birds. The study found that the white color of the turbines attracts the
prey of the birds such as insects, speculating the idea that the birds are then drawn into the blades
when simply hunting for their food. With the idea of birds hunting for their food, scientists
believe that insects and other animals may be attracted to the heat the wind turbines produce
(Zittkowski, 2012). On the other hand, the turbines can have an impact on the amount of animal
fatalities without the animal physically coming in contact with the blades. For example, some
bats have no sign of being hurt by the blades instead the drop of air pressure made by the
turbines is a big enough change that the bats’ lungs explode. These deaths have to be considered
greatly, because the deaths include birds such as the golden eagle and red-tailed hawk which are
both protected under federal and state laws. Zittkowski (2012) stresses the high rates of wildlife
fatalities by stating that the “Altamont Pass Wind Farm in southern California, holding several
thousands of wind turbines, kills between seventy-five and ninety-three thousand birds
annually.” The effects of the deaths can lead to behavior changes with the birds such as

26
dislocation of habitat or traveling for nesting and feeding purposes. The issue became so
apparent that it was brought to court under the case study of Animal Welfare Institute v. Beech
Ridge Energy LLC in 2009. The case focused on the discontinuing of the project to try and
produce more wind turbines in West Virginia. The decision made, resulted in the discontinuing
of the project and having to acquire a permit from the U.S. Fish and Wildlife Service
(Zittkowski, 2012).
All these negative problems can still be reduced and/or possibly eliminated, while still allowing
an efficient means of alternative energy. The topic of location can be a key component for
avoiding the number of collisions. The significance of the location of wind farms can lead to a
decrease in wildlife fatalities due to not building in areas with a large number of birds or bats,
avoiding migration routes (Zittkowski, 2012). Also, a change in decision making should be
enforced as the decision for projects are usually handled on the state level, so federal regulations
should help influence an effective build for a wind turbine farm. Researchers have also
developed a solution that radar technology can be used to detect when there is a flock of birds
coming near the turbines, the turbine will temporarily stop then start up when the air is free
(Zittkowski, 2012). Lastly, the color of the wind turbines as stated before can be painted purple,
a color that seems to attract fewer prey of the birds, leading to less bird collisions.
Location and Animals surrounding Wind Turbines:
Sturm (2013) claims that “Location is important for wind energy because of wind patterns, the
type of plants that grow in the area, and the presence of birds or other flying wildlife.” These are
all great points to consider when thinking of building a wind turbine as the power of wind can
only be so prominent in certain areas. Wind turbines can be built in large secluded open fields or
for personal use in backyards, but wherever they are decided to be put the, flying wildlife will
always be in danger.
Wherever the wind turbines are built, wind has to be prevalent, and that wind, however much it
is, affects the birds and surrounding wildlife. The amount of buildings in the area can affect the
pattern of wind by either speeding it up or slowing it down. All these factors with wind can
change the flight pattern of the birds by either making them fly in another direction or directly
towards the turbines (Sturm 2013).
Usually the most ideal situation for the wind turbines could be a clear open area, with tons of
grass. After analyzing multiple types of birds to learn whether they preferred a certain type of
water or unpaved areas or grass, the majority of birds were attracted to places with plenty of
grass (Sturm 2013). The idea of wind also has an effect on the bird’s flight patterns. The

27
construction of wind turbines can alter a bird’s behavior such as flying, leading them to possibly
not mate or get enough essential resources for them to survive (Sturm 2013). Our team will
attempt to place our wind turbine in the most ideal location, focusing on an area with little to no
bird fly zones.
Effects of Wind Farms on Avian Species and Migration:
The loss of habitat is a direct result when trying to begin construction for a wind farm. In this
case, foraging and breeding areas are destroyed (Sӧmez & Erdoǧan, 2013). The part that makes
the task overwhelming for the surrounding environment is that the amount of area needed to be
cleared is never a set amount. The amount of area needed to be cleared results in the loss of
vegetation, natural rock formation and most importantly, the possible tracks and daily routes of
animals. The loss of habitat leads to displacement amongst the animals making them change
their breeding ranges eventually running into competition with other habitats. Sӧmez & Erdoǧan
(2013), believe that “The displacement occurs due to the turbine’s noise, vibration, silhouette and
the traffic around them.” Researchers have studied the type of behavior of the birds affected by
the placement of the wind turbines showing more than half of the species examined having a
significant change resulting to the construction of the wind turbines.
Wind farms more often than not are set in the path of migration routes for soaring birds,
preventing birds from using their traditional flight paths. The birds are then forced to delay
migrating breeding grounds as well as change their migration routes (Sӧmez & Erdoǧan, 2013).
One idea that is brought to consideration is the term called barrier effect, which certain species of
birds tend to pick up impacting their flight strategies. The barrier effect causes birds to avoid
collision or contact with the wind turbines by flying away or around them. Radar imagery shows
that some migratory birds change their flight trajectories when flying in the area of the wind
turbines (Sӧmez & Erdoǧan, 2013). Also, the different type of bird species affects the amount of
collisions as soaring birds need strong thermals and tailwinds so if the wind turbines are built
around these details, the collision rank could skyrocket. Birds that cannot ascend enough to pass
by the blades will always be in danger of collision (Sӧmez & Erdoǧan, 2013). Also, the niche of
a certain species of birds comes in play as foraging birds usually tend to fly at rotor height.
Conclusions:
My conclusions about these articles and how they affect our project is that they have provided
me with the necessary information on not only wind turbines as a whole, but to the effect on how
wind turbines interact with the surrounding wildlife and what necessary measures should be
taken to reduce the negative impacts on the wildlife. The article provided potentially useful
information which can help the group come about solving the problem statement with attention
to detail and efficiency. The main problem with wind turbines concerning the wildlife is the

28
increasing numbers involving the deaths of different species of birds in the areas where the
turbines are placed. Measures have to be taken when coming up with a design for a wind turbine
to reduce collisions. Additions such as the type of color the wind turbines are can reduce the
collisions as well as add an aesthetic appeal to the surrounding town. Also research in radar
should be looked into further to see if it would be efficient. All in all, collisions from time to
time will occur, but the new designs should reduce the deaths of flying wildlife.
Recommendations:
Based on reading these articles, I would make the following recommendations for our project:
First of all, besides trying to gain maximum wind energy, the number of deaths involving birds
and other wildlife should be significantly reduced through the new design. Research should be
put into the location before constructing the wind turbine, studying what types of birds live there
and how many migration patterns fall in the area. The decision of the appropriate location will
benefit the wildlife in the area such as birds protected under federal and state laws, but also the
people living in the neighborhoods close by the wind turbines. Also, the ideas suggested in the
articles especially by Zittkowski should be researched if the solutions have been tested and either
failed or succeeded. Such solutions like the color of the wind turbine should be explored more to
support how birds are not attracted by certain colors such as the color purple, which can be
implemented into the team’s design. The turbine’s radar could possibly stop the turbines if a
flock of birds is detected, but more research should be placed to see if the constant stopping
could backfire to the turbines’ efficiency. In regards to wind direction if the wind turbine along
with the radar are able to rotate the entire unit in the direction of the wind and away from the
birds, the deaths would be greatly lowered. Upon deciding the location the type of species of
birds should be pressed upon as certain species tend to not even interact with the wind turbines. I
recommend that the team further research and explore these alternative solutions involving
animal safety as a viable solution to our problem statement.

29
From: Clay Mangette
Re: Research Paper 1
Problem Statement:
To design a mechanism that modifies the position of a horizontal axis wind turbine to maximize
power generated in any conditions.
Introduction:
In the past few decades, energy usage has grown exponentially. As energy consumption greatly
increases, fossil fuels and other nonrenewable forms of energy will become expensive and
difficult to secure. In an effort to avoid a major crisis, new forms of energy will have to be used
to generate power. One such form of energy is wind power. This renewable form of energy uses
the kinetic energy of the wind and converts it into electrical energy. This paper will provide a
broad discussion on the functions of wind turbines, but will focus on horizontal axis wind
turbines. The design of turbine blades and new technologies in the field will also be examined
and analyzed. This report will provide the group with essential information on how a wind
turbine functions and a greater understanding of the topic. It may also provide the group with
alternative solution design ideas.
How Wind Turbines work:
As previously stated, wind power works by converting the kinetic energy in wind to electricity.
This energy is collected by large fan-like structures called wind turbines. There are two main
variations in how turbines are structured: horizontal axis, in which the axis of rotation is parallel
to the ground, and vertical axis, in which the axis is perpendicular to it. Vertical axis wind
turbines tend to have an eggbeater-like shape. A common trait of horizontal axis wind turbines is
the use of three fan blades. Although both types of wind turbines appear different, they both
carry out the same function. Wind pushes the fan blades, causing them to move. From there, a
generator spins around, causing electromagnetic induction. Electrical energy is generated and
then distributed across an electrical grid (“How do Wind Turbines Work”, 2013).
The website reference above also provides an interactive animation that provides more detail into
what parts make up a horizontal axis wind turbine. Housed next to the rotor is a pitch system that
controls the blades and will move them if the winds going into the rotor are too strong or weak.
A low speed shaft leading into the gearbox turns as the wind turbine moves. From there, the
gearbox uses its gear ratio to increase the speed of the generator, which is connected to one of
the gears. As previously stated, the generator creates electrical energy, in the form of alternating
current. There is also a controller behind the generator that will shut off the turbine if the wind
speed is too high to prevent damage. In case of emergency, there is usually a braking system
integrated into the windmill (“How do Wind Turbines Work”, 2013).
Factors affecting Turbine Blade Design:
When designing a horizontal axis wind turbine, one of the most important parts of the design will
be the turbine blade. The turbine blade’s design affects how efficiently it can collect wind and
there a number of factors that determine how efficient a turbine will be. As a reference, the

30
efficiency of a turbine is defined by how much energy a turbine can collect compared to what it
should be able to collect theoretically. Because 100% efficiency can only be achieved if
assumptions are made that defy the laws of physics, the calculated maximum possible efficiency
was determined to be around 59% (Schubel & Crossley, 2012).
Schubel and Crossley go on to detail many design choices engineers need to make when
designing a turbine blade. The first decision is to decide whether to use a horizontal axis wind
turbine or vertical axis wind turbine. Vertical axis oriented turbines have the advantage of having
no additional load on their structure, because most of the heavy machinery can be mounted on
the ground. However, they also have a disadvantage of not being able to start turning on their
own. Horizontal Axis Wind Turbines do not have this disadvantage, but do have more stress put
on its structure because most of the parts are located at the top of the structure. In most cases,
horizontal axis wind turbines are chosen because the rotor speed on vertical axis turbines can be
difficult to control and are not self-starting (Schubel & Crossley, 2012, pg. 3426).
Another important decision to be made is whether the turbine will use lift or drag for propulsion.
Drag operated turbines tend to have a vertical axis orientation, and some have cups or planes in
which the wind pushes. Turbines that use lift, however, can be either vertical axis or horizontal
axis oriented and tend to have their blades angled to produce lift. Turbines using drag forces
have proven to be less efficient because the drag force is more dependent on the direction of the
wind than lift is. While drag propelled rotors can produce an efficiency from 8%-16%, lift
propelled rotors can have an efficiency as high as 50% if implemented correctly (Schubel &
Crossley, 2012).
Schubel and Crossley make the assertion that “The tip speed ratio defined as the relationship
between rotor blade velocity and relative wind velocity [Equation (2)] is the foremost design
parameter around which all other optimum rotor dimensions are calculated,” (Schubel &
Crossley, 2012, pg. 3430). The authors Schubel and Crossley define tip speed ratio as the ratio of
the multiple of rotational velocity and radius divided by the wind speed. For a modern horizontal
axis turbine blade, a speed tip ratio of six to nine is desired. Any higher would cause stress on the
system. The speed tip ratio directly affects how the blades are designed. According to the chart
provided by the authors, a turbine that is utilizing three blades and needs a tip speed ratio of ten,
would have a very thin blade compared to a single bladed design that required a speed tip ratio of
five (Schubel & Crossley, 2012, pg. 3432, figure 3).
Emerging Technologies – The Variable Ratio Gearbox:
As wind power becomes more common as a method of generating energy, new technologies will
begin to emerge. One such technology is the variable ratio gearbox (VRG), which according to
authors Hall and Chen (2012),”can increase the efficiency of a fixed speed, stall regulated wind
turbine by at least 7%.” A variable ratio gearbox is described as a gearbox that would be located
in the drive train to change the gear ratios between the turbine itself and the generator. This
would allow the turbine to run at varying speeds, but the generator’s speed would be constant
(Hall & Chen, 2012, Introduction, para. 3, 4).
The two authors give substantial evidence to support their claims with research on how a VRG
will perform under different conditions. For the data collected, the VRG’s used were designed to

31
house six gears with ratios ranging from 14.71 to 21.59. At one site, the wind turbine being
tested increased its power output from 1642 kilowatts to 2070 kilowatts, with an increase in
power of 26% with the VRG. According to the histograms provided by the authors, both the
efficiency and power increases tend to be the greatest when the wind speed is between 8-16
meters per second (Hall & Chen, 2012, section 3.2, figure 3). Across all of the test sites, a
significant increase in power generation was observed, ranging from seven to ten percent (Hall &
Chen, 2012, table 4). The authors conclude that the VRG is a low cost option that will increase
the production of a turbine by at least seven percent (Hall & Chen, 2012, Conclusion).
Conclusion:
The information provided by the articles will likely be beneficial to the group. Authors Hall and
Chen provide important background information about the problem given to the group and some
even offer solutions to it. The first article, while short, gave a summary about wind turbines and
provided background information that would help me understand the more detailed articles. The
article that describes how turbine blades are designed provided a very detailed and technical
explanation of the process. This article should be very helpful in determining what constraints
need to be met while modifying the horizontal axis of the wind turbine. The article that details
the variable ratio gearbox will likely be the most helpful, because unlike the other two articles, it
has the potential to be a direct solution to the problem. The variable ratio gearbox was proven by
the authors of the article to increase power production and offers a solution for at least increasing
efficiency in horizontal axis wind turbines.
Recommendations:
Based on the information presented in the articles, these are my recommendations for the group:
Each group member should at least read over the article “How do wind turbines work?” The
information presented by this article is essential to the project. Each group member should have a
basic understanding of how a wind turbine functions after reading this article. I also recommend
that the group look into how turbine blades are designed by reading over Wind Turbine Blade
Design. There are numerous constraints that are considered when designing a wind turbine blade
including orientation, propulsion system, and blade shape. These constraints need to be taken
into consideration when the group decides to begin generating alternative solutions. The possible
alternative solutions will have to satisfy these constraints and the group should use these
constraints to evaluate solutions. I also recommend that the group look into how variable ratio
gearboxes function. The research done by the Article “Performance of a 100 kW Wind Turbine
with a Variable Ratio Gearbox” supports the claim that the variable ratio gearbox increases
power generation and efficiency of wind turbines significantly. I believe that the VRG, while it
doesn’t alter the horizontal axis position, can be incorporated in any of the alternative solutions
to improve performance. It’s recommended that the group continues to research the properties of
the VRG in order to gain a better understanding of it and possibly use it in our design.

32
From: Cyrus Vakili
Problem Statement:
Introduction:
The popularity of wind turbines has been steadily increasing because they are a good way of
creating renewable energy. The drawback of these horizontal-facing wind turbines is that they
create energy only when the wind is moving in the direction that they face. To make these wind
turbines more efficient, they need to be able to face any direction and generate energy. This will
require a major redesign of the wind turbines that are currently being constructed. With this
redesign, the annual cost of maintenance for the wind turbine must be considered and kept to a
minimum in order to make the wind turbines as efficient as possible. This paper will go into the
details of creating a new and more efficient wind turbine while keeping their maintenance and
upkeep to a minimum.
Traditional Horizontal Wind Turbine Drawbacks:
The traditional horizontal wind turbine has a few flaws with its design that does not allow it to
maximize the amount of energy it creates. The main drawback is that wind turbines must point
into the wind to generate power and produce energy. If the wind shifts, the wind turbine
becomes less efficient and is unable to produce energy (Herbert, et. al. p. 1126). If wind turbines
are going to become an increased source of energy, they must be built in a way that they can face
any direction and still produce energy. This will completely change the design of a traditional
wind turbine. The traditional wind turbines that are being produce are also very loud and take up
a large amount of space. In addition to this, many people that live near wind farms do not like
the look of the giant spinning blades. People living in close proximity to wind turbines believe
that the turbines ruin the view of nature because they are usually placed high up on hills. These
problems and drawbacks will need to be addressed during the redesign of the wind turbine.
Maintenance of a Traditional Wind Turbine:
A wind turbine takes a lot of maintenance to keeping running and generating power. The
maintenance is necessary to fix and prevent failures that can occur. A larger wind turbine is
prone to have more failures than a smaller one. A typical wind turbine usually has one failure
per year. These failures can happen to almost any part of a wind turbine. The parts of a wind
turbine that fail most often are the electrical system, control system, and the gearbox. The most
costly of these failures on a wind turbine occur when the gearbox breaks down (Herbert et al.,
2007). Gearbox failures account for 20% of the failures on a wind turbine. The gearbox is a

33
very critical component to the wind turbine and is costly because it takes a very long time to
repair. In some cases it takes ten days of maintenance work to repair a gearbox because it is so
heavy and hard to access within a turbine. All of these failures can cause the wind turbine to
stop producing power entirely. This cuts down on the efficiency of a wind turbine and does not
allow it to be as helpful to the economy or the environment as possible. Preventive maintenance
done on a wind turbine is very important to keep it running for as long as possible without a
break down or failure.
A traditional wind turbine is rated to last 20 years, however, this lifetime is rarely reached
because the technology for wind turbines is increasing so rapidly. These new designs and
technological advances often replace old existing wind turbines before they reach their 20-year
limit. Since wind turbines usually do not reach their age limit, there has not been as much data
collected from wind turbines older than 15 years. With an increased lifespan and usage of a
wind turbine as a source of energy, the cost of maintenance and repairs will go up. This will
make optimizing the maintenance of a wind turbine for the cost imperative.
Redesigned Wind Turbine Advantages:
The redesigned wind turbine can have many advantages as compared to the traditional turbines
that are in use today. If the new wind turbines are able to create power and energy facing any
direction, this will increase the amount of time that they run for and thereby make them more
efficient. One solution to making this possible would be to design a way for the wind turbine to
rotate into the direction that the wind is coming from. If the wind turbines work more often, they
will begin to need more maintenance to prevent and fix failures that occur. To make the turbines
more cost effective, the maintenance of a wind turbine should be quantitatively addressed
(Andrawus, 2008). Examples of these methods are Modeling System Failures (MSF) and the
Delay-Time Maintenance Model (DTMM) (Andrawus, 2008). This quantitative method should
allow the company operating the wind turbine to find a balance between the cost and benefits of
the maintenance. Even if the maintenance time of the wind turbines increases slightly, the extra
power output caused by the extended running time should outweigh the cost.
With the new design of the wind turbine, it will be possible to make smaller wind turbines that
output the same amount of energy. As previously discussed, smaller wind turbines do not break
down as often and are more efficient because of this. This will allow for the turbines to run for
an even longer period of time before they need maintenance or repairs. Smaller wind turbines
that generate the same amount, or possibly even more power and energy will also save space
where wind turbines are placed. This could allow for the possibility to add extra wind turbines to
wind farm, thus generating even more power. A turbine with a rotating head that could face any
direction would greatly improve the capabilities of a traditional wind turbine. It will allow wind
turbines to output more power and energy to the surrounding areas. The greater output of usable
energy can offset any additional maintenance costs and make the wind turbines more efficient.

34
Creating a wind turbine with a rotating head will ensure that wind energy continues to contribute
to the worlds energy supply in the future.
Reducing Bird Strikes to Wind Turbines:
Whenever wind turbines are placed on land, there is the threat of birds colliding with the
structure and potentially damaging. Wind turbines are a very finely tuned mechanical structures
that shouldn't take any extra stress from bird strikes. When this happens, it is very possible that
the bird causes damage to the blades of the wind turbine. This increases the maintenance
necessary to keep the wind turbines running and make them less effective and more costly.
Damaged wind turbine blades account for 13.4 % of all wind turbine failures (Ribrant, 2007).
This percentage could be reduced if the bird strikes to the wind turbines decreased. Bird strikes
also cause a number of avian fatalities. Bird strikes causes a decrease in the bird population of
the environment surrounding the wind turbines. Preventive measures can be taken to deter birds
from flying too close to wind turbines and causing them damage.
If preventive measures were put in place to reduce bird strikes to wind turbines, it would cause a
decrease in the amount of damage that the blades receive from birds strikes. One possible
solution to the bird strikes would be to cover the wind turbines with UV light reflective stickers.
Birds have been shown to be sensitive to light in the 315-400 nm range which is ultra violet light
(Banks, 2001). These reflective stickers deter birds by shining UV light from the sun at the birds
and causing them to fly away. Humans do not have the ability to see this range of light and
would be unaffected by it. If this technology was applied to the wind turbines, the percentage of
bird strikes would likely decrease a significant amount. This would decrease the damage to wind
turbines and the maintenance they would need to keep them running. The decrease of accidental
deaths would help the bird population go up. These UV stickers are a good investment in the
wind turbine industry not only for the birds that are safer, but also for the wind turbines which
become more efficient and require less maintenance.
Conclusions:
My conclusion about the articles and how they relate to the topic of wind turbines and
maintenance is that they have greatly increased my knowledge about the working parts of a wind
turbine and what the best ways are to maintain them. This knowledge will help the team to
develop a better wind turbine based on what we have learned. These articles provide information
that will be beneficial as the team tries to answer the problem statement. Wind turbines that are
already in place are a good benefit to the environment and clean energy, but they could be
greatly improved upon. With a redesign of the turbines that allows them to rotate and deter
birds, it could be possible to expand the usage of wind energy in the future. At the same time, if
the maintenance required for a turbine is reduced, they will become more efficient and a good
investment to make for future energy.

35
Recommendations:
Based on the articles, I would make the following recommendations for our project:
Wind energy is a renewable resource that is worth pursuing and developing in the future as an
alternative source of energy. To complete this solution, the traditional wind turbines need to be
modified in their designs to make them capable of generating more power. It would be most
beneficial for the wind turbine to have a rotating head in order to be able to create wind energy
from any direction. The amount of maintenance that would be needed to allow the wind
turbines to operate year round with the new design would need to be considered. The amount of
power would need to be great enough to offset the cost and maintenance of the additional run
time. A rotational wind turbine with the ability to face any direction and produce power would
be a great benefit to the environment as it would reduce the energy used from coal or natural gas.
If the wind turbines were outfitted with type of bird repellant, that would help sustain that
population in the region as well. Our client would benefit greatly with a wind turbine that
operates in any direction. I suggest our team further research to come up with the best design
possible.

36
From: Martin Pelic
Problem Statement:
Introduction:
Since the dawn of the industrial revolution fossil fuels have been the primary energy source for
the world, but in today’s world there is a push towards alternative sustainable energy sources.
Wind power has proven itself to be one of the best alternative energy sources and has been
around since the beginning of recorded time. Modern wind turbines have been successfully
implemented in wind farms all over the world, but continue to have problems with efficiency as
well as creating a negative impact on the environment. Many of the problems associated with the
efficiency of wind turbines centralize on their inability to harness wind coming from all
directions. Wind turbines also cause unnecessary fatalities of wild animals, mainly birds. Many
people also feel that wind turbines visually pollute the areas in which they are built. Because of
these issues there is a notable public opposition to wind farms. This paper will discuss the
public’s criticism with modern wind turbines and farms, as well as propose possible solutions to
these problems.
Public Criticisms of Wind Turbine Aesthetics:
In his research, Gipe (2011) found that people desire a visual cleanness (Gipe, p.244). Gipe cites
human nature, by referring to our need to create order in the hectic world, which we inhabit.
Because of this, California’s wind projects have been received as visually disorganized based on
the spacing between wind turbines and their orientation. Maintaining a constant spacing and
orientation of wind turbines can help reduce the visual pollution that is often referred to as a
main concern when discussing wind turbines. Gipe refers to a Dutch study that when surveyed,
people accepted that the sight of technology in nature, mainly wind turbines, as a sign of
progress and advancement of technology. With this said, the public demands that these pieces of
technology be visually ordered (Gipe, p.244-245).
Gipe makes several other suggestions to help ease the visual strain created by wind turbines.
When designing a wind farm it is important that every wind turbine’s blades spin in the same
direction. In addition to this, only one design of turbine with a consistent height should be used
throughout the entire wind farm because it creates a smoother image when viewed. Wind
turbines are often viewed while they are at rest or “parked”. Because of this, a special

37
consideration should be made as to what they will look like when they are parked. When parked,
the turbine’s blades should rest in the same orientation (Gipe, p. 245-246)
Protecting Birds From Wind Turbines
In the data presented by Anderson et al. (2006), it is shown that humans cause nearly 1 billion
avian fatalities annually, in the region of North America alone. Things like power lines,
buildings, communication towers, vehicles and pesticides cause the majority of these fatalities.
Together, these reasons contribute to 85% of avian fatalities per year in North America. Current
studies show that wind turbines contribute to less than 0.01% of bird fatalities in North America.
Although this number seems trivial, many of the birds killed by wind turbines are species that are
of great concern because of their already low populations in North America. Raptors are the
avian species that seem to warrant the most concern when it comes to wind turbine fatalities
(Anderson et al., 2006).
There seems to be several reasons that can explain why wind turbines cause so many avian
fatalities. Anderson et al. (2006) states that the prey of many avian species are attracted to either
the airspace around wind turbines or the fields in which turbines are commonly located. Raptors,
which are birds of prey, commonly hunt for rodents. These rodents are attracted to the areas
where wind turbines are located because turbines are usually located in open grassy fields. Red-
tailed hawks, great horned owls, and American kestrels are specific types of raptors that appear
to have the highest chance for collision with wind turbines. Wind turbines are also located in
areas where migrating birds commonly pass through. These theories can explain deaths of certain
species of birds (Anderson et al., 2006).
Avian deaths due to wind turbines have become a matter of great concern, but there are new
solutions that can reduce the number of fatalities caused by this particular alternate energy
source. Anderson et al. (2006) suggests that, prior to wind turbine installment, a thorough study
of the area should be made to insure that it would have a minimal impact on the avian population
in the area. These studies should include a report on the avian population and their flight patterns
in and around the area. By avoiding building wind turbines with high avian populations, the
number of birds killed by wind turbines can be greatly reduced. Installing monitoring devices
that detect large flocks of birds that can shut down the wind turbines when flocks of birds
approach the turbines have also been proven to reduce bird fatalities. Decommissioning broken
or non-operational wind turbines and burying all power wires can also reduce the number of
things birds can run in to (Anderson et al., 2006).
Wind Turbine Materials:
There are several materials used in the construction of modern wind turbines. Advances in
manufacturing of certain materials have allowed for wind turbines to be built with stronger and
more durable materials for lower costs than in the past. Research by Ancona and McVeigh

38
(2001) has shown that the towers of modern wind turbines are making the shift from being
comprised of steel to pre-stressed concrete. Pre-stressed concrete is a lower cost material,
however it still needs to be reinforced with steel and this keeps the cost relatively close to steel
towers. The blades of most wind turbines are made of glass fiber-reinforced-plastic (GRP), but
with the implementation of longer blades on larger wind turbines, the focus has been on higher
strength materials such as carbon-filament-reinforced-plastic (CFRP) and steel. These materials
tend to be stronger and have a longer lifespan (Ancona & McVeigh, 2001). Because of the
increasing knowledge of how to make wind turbines simpler, more efficient and less expensive,
there can often be more focus placed on making turbines more visually appealing, while at the
same time lessening their impact on the environment in which they are located.
Conclusions:
These articles provide knowledge about previous wind turbine projects and their successes in
making wind farms more visually appealing as well as reducing bird fatalities. Understanding the
materials used in wind turbines can also provide a better understanding of how they can be used
in our project. By having a better understanding of the materials used in wind turbines and how
newer materials can make them more efficient and less expensive, there may be the possibility to
reduce the size of wind turbines, which can reduce the chances of bird strikes. Reducing the
visual impact that wind farms tend to have can help increase public support for our wind turbine
design, and make it easier to implement. Implementing systems to reduce avian fatalities can also
help reduce public opposition to wind turbines. Using these methods, there will be reduced avian
fatalities as well as less visual pollution caused by wind turbines.
Recommendations:
Based on reading these articles, I would make the following recommendations for our project:
When installing our wind turbines, there should be a close attention paid to how they are spaced
and oriented. An even spacing between each wind turbine should exist and all blades should
rotate in the same direction. When turbines are parked, all blades should rest in the same
orientation in order to create visual unity. A consistent height should also be kept for all turbines
for the reason of creating a more appealing sight when viewed. For the purpose of reducing avian
fatalities, there should be monitoring devices such as radars that detect large flocks of birds and
automatically disable the wind turbines when the birds are close enough to the turbines. Studies
should also be conducted to find the ideal area for wind turbines to be built so that they will not
lie in areas where migrating birds tend to fly through. A closer look should also be taken at the
materials of wind turbines in order to reduce costs and improve efficiency, while reducing the
size of wind turbines in order to reduce bird fatalities. I recommend that further research should
be done on these ideas in order to find a possible solution to our problem statement.

39
From: Daniel Thornton
Problem Statement:
Introduction:
For centuries, the world we live in has been relying on the use of non-renewable energy sources.
Our planet can no longer support the rate at which we use those sources. In an attempt to save the
planet we live on, scientists have devoted a lot of time and money on finding efficient ways of
obtaining renewable energy. One of the renewable energy options that scientist have tried to
perfect is wind turbines. Wind turbines are mechanisms that produce usable energy through the
work done by wind. Wind will cause the blades on the turbine to spin, which then powers a
generator that is located inside the turbine. The energy used by the wind to push the blade is then
converted to other types of energy through the generator. One of the problems associated with
wind turbines is that they are not placed in optimal locations to produce the most energy. This
paper addresses the factors that are needed to take into consideration when choosing a location
for a wind turbine. Determination of location is done by analysis of different characteristics of
regions across the U.S., the study of fluid mechanics, and the examination of different wind farm
arrangements.
Regional Wind Studies in the United States:
Some of the characteristics that must be taken into account when choosing the best region are
wind patterns in that location, and accessibility to the land and the turbines. Wind turbines can’t
function properly without an ample supply of wind, so it is essential that they are placed in a
region that experiences a significant amount of wind. Studies show that the windiest regions of
the United States are located along the coasts and towards the center of the U.S., specifically,
North Dakota, South Dakota, Montana, Eastern Wyoming, and Northern Nebraska (Tchou,
2008). Building wind turbines on the eastern and western coasts would be difficult considering
they are densely populated by thriving cities and residencies. This means that the wide open
central United States would be the optimal region to place wind turbines.
Accessibility becomes important because it is necessary to be able to build your turbines on the
desired land. Accessibility refers to the fact that a lot of the land in the United States is restricted
due to forest conservation and other environmental reasons. Accessibility also pertains to the
idea of being able to retrieve the collected energy from the turbines. This process is carried out
by connecting the turbines to a transmission grid. The profit in the collection of this energy could
be greatly devalued depending on the distance to the nearest transmission grid. Taking these
factors into consideration, it becomes apparent that North Dakota is the best option for turbine

40
placement. Eastern Wyoming, South Dakota, and Northern Nebraska still stay within reasonable
consideration for turbine placement (Tchou, 2008).
Using Fluid Dynamics to Determine Placement of Wind Turbines:
Fluid dynamics becomes useful in the placement of wind turbines when you think about location
in relation to obstacles like buildings. Obstacles like these become a factor because they interfere
with the wind that passes through that region. When the wind encounters these obstructions, it
obviously is unable to pass through the object; instead, it finds an alternate route around the
building. Due to this detour, the power density of the wind tends to be scarcer closer to the
building. A study was performed at the Massachusetts Institute of Technology where researchers
took readings of wind power density at a height of 20 meters all around campus. The study
shows that the wind power densities around the walls of the building are close to or equal to
zero. Once you move away from the building you begin to see an increase in the wind power
density. The power density reaches its peak in the middle of an open field, where it measures to
be about 110 W/m2
(Kalmikov, 2010).
In the same study, measurements of wind power density were taken at varying heights above the
open field, ranging from ground level to heights well above the rooftops of all buildings in the
area. The Results show that the wind power density was lowest at ground level, about 20 W/m2
(Kalmikov, 2010). This is probably due to the fact that most obstructions are located at ground
level, therefore, interfering with the wind reaching the open field. As the height of the
measurements increased, the value of the wind power densities also increased. The
measurements peaked once the height of the recording was higher than all of the buildings in the
area, reaching as high as 230 W/m2
(Kalmikov, 2010). Power densities are highest at greater
altitudes because there are fewer objects interfering with the flow of wind.
The Arrangement of Wind Farms:
The arrangement of turbines in a wind farm could be detrimental to the efficiency of the farm.
The arrangement is dictated by the effects of the wake of one wind turbine on the other turbines.
When the wind passes through a turbine, it causes some sections behind it to experience very
strong winds and other places to experience little or no wind. It becomes important to place
turbines in the correct winds because turbines could become damaged by the very strong winds
or be useless in the middle of the weak winds. According to Samorani, a formation that will
allow turbines to avoid the wakes of other turbines would be to arrange them in a row with 3 to 5
blade diameters between each turbine. Once rows are formed, you can arrange them one in the
back of the other with a distance of 5 to 9 blade diameters between each row. Each turbine
should be equidistant from two turbines ahead of them (Samorani, 2013).
Although this arrangement will prevent the negative effects of turbine wakes, it does not
optimize the output of the wind turbines. This method will simply keep the turbines from hurting

41
each other’s production, but Samorani is convinced that there is an arrangement that will allow
each turbine to benefit off of the wakes produced by others. That optimal formation has not yet
been discovered and will need further research to draw definite conclusions (Samorani, 2013).
Conclusions:
In conclusion, these articles have been very helpful in furthering my understanding of my
project, and ultimately furthering the understanding for my group. Through this research, we will
be able to determine which region in the United States would be best for our wind turbines. It is
important to have a windy location because that is what the turbines rely on to generate power.
Without wind, those turbines would be useless structures in the middle of a field. We will also be
able to draw conclusions about placement of wind turbines in relation to nearby obstacles, and
placement in relation to each other through the studies of fluid dynamics. Placement of turbines
in relation to other obstacles, whether it be buildings or other turbines, becomes important when
we talk about their effectiveness. Obstacles can cause winds to become weaker or stronger,
depending on where you take a measurement. Placing a turbine in the weak winds will render
them useless and placing them in the areas of the strong winds will cause maintenance issues.
Taking all these factors into account, my group will be able to choose the most effective location
to place an efficiently arranged wind farm.
Recommendations:
In addition to the information learned from these articles, I would make the following
recommendations for our project:
Areas of North Dakota, South Dakota, eastern Wyoming, and northern Nebraska should be
researched in order to be certain that the area we plan on occupying is accessible and clear of any
obstructions that could hurt the outcome of our wind farm. Granted that those conditions are
fulfilled, further research should be done to see what kind of environment that region will grow
to be during the duration of our project. Research is necessary because buildings could be created
and other obstructions could develop that would render the production of the wind turbine. I
would also recommend that my team further research the possibility of an optimal arrangement
of wind turbines within a wind farm. Based on research done by Samorani, there will eventually
be a formation which will increase the efficiency of the generation of power of wind turbines. It
is important that my group gain access to that information as soon as possible so that we can
make our wind farm perform at its highest level. A final recommendation I would make would
be to research the weather conditions in our desired location. Turbines are not known to work
well in extreme cold, and could possibly freeze over under the right conditions. My team should
take these recommendations into consideration and conduct research accordingly.

42
From: Jake Groezinger
Problem Statement:
Develop a mechanism that would vary the position of the horizontal axis of wind turbines to
maximize electrical output in any wind conditions.
Introduction:
Wind energy is becoming more and more relevant in society and it is one of the primary
alternatives to the fossil fuels that are used today. In 2010, 2.5% of worldwide energy was
produced from wind turbines. The horizontal axis category of wind turbines are very dependent
on wind direction, and for this reason, our team will design a system used by the turbines that
allow the horizontal axis to be varied in order to maximize the power output of the turbine. The
power output of the wind turbine is the most important part because the power output is a direct
result of the efficiency of the turbine as a system. There would be a greater usage of wind
energy worldwide if the wind turbines were more efficient, and the goal of our project is to do
just that. By designing a system that allows the horizontal axis to be varied, we can get the most
out of the wind turbines at all times during the day. In addition to the inefficiency of the
horizontal axis turbines, bald eagles are continuously flying into the blades of the turbines while
they search for prey. For this reason, our design will reduce the number of bird fatalities. The
issues that are brought up with wind turbines will guide our redesign of the wind turbine. There
are many ways to approach these issues and there are many criteria for evaluation. One of the
main points of evaluation of our design will be the cost of the wind turbine and the production of
energy. The cost of wind turbine construction, maintenance, and power production will be the
focus of this paper. Also, the comparisons between the costs of wind energy with the other
relevant forms of energy.
The Economics of Renewable Energy:
The greatest quantities of wind turbines are in Denmark and Germany, but these countries are
also where the price of energy is the highest (“The Economics of Renewable Energy”, 2009).
This relationship is very relevant worldwide because the price of wind energy is much greater
than the price of fossil fuels. In Britain, the price of electricity generated from wind turbines is
twice that of the cost of electricity produced from traditional sources such as fossil fuels (2009).
The main obstacle that is causing the high prices of energy from wind turbines is a renewable
generator. Renewable generators are more expensive than traditional generators, and they also
require more frequent maintenance. The renewable generators are more costly than traditional
generators because of the complexity of the wind turbines and the storage of energy involved
with the generators.

43
Most wind farms are built in rural areas because rural areas have more open areas. Therefore,
allowing more room for wind turbines to be installed and the turbines are more open to the wind.
Even though the rural areas are great places for wind turbines to be installed be operated,
transporting the electric power produced by the turbines from the rural areas to urban or
suburban areas is extremely expensive. For this reason, the cost of wind energy is higher than
other sources of energy. Even though this is the case, it is possible to have wind turbines
installed on the outskirts of cities such as Atlantic City, New Jersey. In Atlantic City, the wind
turbines that are used by the city are along the coast where there is more wind, and the area used
is rural enough for the installation of a wind farm without impeding on the city at all.
Why is renewable energy so expensive?
Throughout this article the author makes many suggestions about what needs to be improved
with wind turbines in order for wind energy to become more valuable economically. The author
suggests that in order to fix the problem of wind energy being invaluable, new storage
technologies need to be worked into renewable energy systems (“Why is renewable energy so
expensive?”, 2014). The concept of energy storage technologies plays an integral role in the
evolution of wind energy because the wind does not always spin the blades of the wind turbine.
Storage technologies would allow wind energy to be built up during time of high wind and this
would offset the deficit that the wind turbines experience during durations of low wind (2014).
Wind turbines only spin during about one-third of their lifespan. That means that they are
producing on average two-thirds less energy than other sources that are constantly producing
energy. If a wind source is able to spin rapidly during a period of high wind, that energy would
be stored in an energy storage unit allowing there to be a constant flow of energy to the
destination.
The cost-effectiveness of wind energy is the main drawback because it is the cleanest available
source but the current initial costs of wind power is too expensive and the average return on
investment over the lifespan of a wind turbine is not as high as it had been in the past.
Implementing new technologies that increase the productivity of each individual wind turbine
along with lowering the cost of the production of wind energy, resulting in a greater use of wind
energy and cleaner energy in the future.
Institute for Energy Research | The Hidden Costs of Wind Power:
The embedded costs of wind energy are described in this article in great depth. The article states
that wind energy is responsible for 3.5% of the energy produced in the United States (Institute
for Energy Research, 2013). Government tax subsidies that will be given to wind operators over
the next ten years were also discussed along with the average cost of wind energy compared with
the average cost of fossil fuels. In comparison with natural gas, wind energy costs 6-7 cents per
kilowatt-hour more than its benefit (2013). This deficit is the reason that new technologies and

44
transfer methods need to be put in place in order for wind energy to be the best option for power.
New technologies for energy storage along with cheaper and more efficient transfer methods will
bring the cost of wind energy down and make it a more popular energy source in the world.
These costs that are associated with wind energy are the reason that people aren’t investing in
wind energy. If the embedded costs were reduced, more capital would be invested in wind
energy, resulting in a greater use of the energy source.
Conclusion:
In conclusion, wind energy is becoming of the most relevant forms of energy production, but
there are a few obstacles that it faces in order to be as popular and as widespread as fossil fuels
or other forms of energy. With these problems solved, the usage of wind power will become
widespread and the cost of wind energy production will decrease. Our redesign of the wind
turbine will solve the problem statement of the horizontal axis needing to be moved and it will
also reduce the number of bird fatalities currently caused by wind turbines. One of the key
factors that will be brought into this project is cost and efficiency and how they both play a role
in the relevance of wind energy.
These articles have applied to our group in many different ways because it has allowed us to
view the project from different angles and the articles have helped us to brainstorm many
different ideas. Personally, I have learned a lot about the specific costs and aspects of wind
energy and why wind energy isn’t as widely used as many people had hoped. These articles
gave insight into the steps that need to be taken in order to increase the use of wind energy and
they also showed me the hidden costs of wind energy production. These concepts will play a
huge role in our project because we need to enhance the wind turbines but also keep cost in mind
while we do so. With cost being one of the main points of evaluation for our redesign, the cost
of the redesign should always be one of our top priorities during this project. Keeping our
budget and total costs in mind, we will be able to re-design the wind turbine to meet our goals
and keep the total costs of the redesigned wind turbines realistic and competitive.
Recommendations:
Based on these articles, I would like to make the following recommendations for our project:
Wind energy is found to be very costly, especially in terms of initial costs. I believe that costs
need to be taken into very careful consideration because with wind energy already being
expensive, we can’t afford to make it any more costly for potential operators or investors.
Integrating storage technology would make the redesign very valuable to the CEO. A new
technology such as that would make our wind turbine very marketable due to the long-term costs
and higher efficiency. Lastly, making wind turbines available in areas close to urban or
suburban areas would greatly increase the widespread use of wind energy because the costs of
the transportation of the power will be lower than it would be if the turbines were in rural areas.

45
Making these modifications to our design will make our final product better because there would
be a greater will to invest in wind energy, therefore causing a greater demand for wind turbines.
These recommendations that I make to my group will aid my group in understanding what we
need to do to create a successful project. A successful project will promote wind energy and
encourage more people to look into investing in renewable energy as a whole. With all of these
recommendations considered, I believe that we will have the best possible solution for our
problem statement.

46
From: Mackenzie Ficker
Problem Statement:
Introduction:
Over the past few years, engineers and scientists have been discovering new, clean energy
sources, which can be used to replace coal and oil, so that the environment can be spared for
generations to come. However, none of these sources have become advanced enough to
completely replace non renewable energy sources for multiple reasons, such as efficiency or the
fact that it costs more than having coal or oil be used instead. One of the more recent attempts at
generating a new source of energy is through the use of wind turbines. This process works by
having a turbine be placed in an area that had a large amount of wind going through the area. At
first, manufacturers believed that turbines could be placed in a relatively close distance to human
populations as long as the turbines could not be heard. However, scientists and engineers did not
immediately know that these turbine could affect the health of the people surrounding them, so it
has not become a huge source of power that can be supplied because there are only certain areas
where they can be placed. This helps our project because it gives insight into the symptoms that
can occur as well as why those symptoms occur. If the cause of the health symptoms is known,
we can start to research ways to stop them.
Health Effects:
There are many different health effects that have been associated with wind turbines. The main
symptoms that go along with wind turbines include: Sleep deprivation, stress, blood pressure
elevation, and memory dysfunction, just to name a few (Salt, 2013). These can drastically affect
a person’s quality of living, and can even lead to larger health problems in the future. There
have been numerous cases throughout the country of Canada of individuals who have had to
leave their homes because their health was deteriorating quickly (Jeffery, 2013). Jeffery’s article
states that the health effects that Industrial Wind Turbines (IWT) have on individuals is so great
that many people throughout Ontario who live near IWTs have either come to a financial
agreement with the developers of IWTs or otherwise have completely abandoned their homes.
When talking about the effects that IWTs have on individuals, it is important to know that the
World Health Organization has defined someone who is in perfect health as “a state of complete
physical, mental and social well-being and not merely the absence of disease or infirmity
(Jeffery, 2013).” After researching the effects that wind turbines have had on many people, one
can conclude that these people are not healthy at all, and should not have to deal with living near
an IWT. Even though this definition of a healthy person is accepted worldwide, IWT developers
have not taken this into account when placing IWTs, which has caused people to be uprooted
from their homes, or be forced to deal with the severe health effects that go along with living
near a wind turbine. More research must be done to determine how far a wind turbine should be
placed from any human population.

47
Science Behind how Wind Turbines Effect Humans:
In Salt’s article, he goes into the science behind how wind turbines can affect the health of
humans. Large IWTs tend to generate low frequency sounds that cannot be heard by humans,
but our ear drums can still detect this sound waves and respond accordingly. These low
frequency waves are called infrasound waves, and have the biggest effect when there are either
low level or no other sounds nearby. This explains how IWT engineers are not really affected
when maintaining and building new IWTs, but homeowners who cannot audibly hear the
turbines can be affected by IWTs.
Salt then goes on to describe how infrasound waves can affect the sensory cells of the ear in such
a way that it can cause the sensitivity of our ears to go up and down, much like turning the
volume of music up and down repeatedly. This can cause random eye movements or tension of
the neck muscles that are otherwise unexplainable, however, this is the mildest of the effects that
IWTs. This is why one of the symptoms is sleep deprivation, because even though one cannot
hear what woke them up, they will keep repeatedly waking up throughout the night while the
wind turbine is still running.
Another effect that IWTs can have on humans and other animals is hearing loss. This is due to
the infrasound waves, which can harm you slightly when by itself, but raise the effects of that
other sound waves have on hearing loss, such as mowing a lawn near a source of infrasound
waves. Most over ear hearing protectors do not affect infrasound waves, only waves that are
audible to the human ear, so either way infrasound waves can cause hearing loss over time,
however it is drastically affected with the combination of infrasound waves and audible sound
waves. At the end of Salt’s article, he goes into detail about how more research is still needed so
that we can fully understand all of the symptoms that IWTs can cause, as well as why these
symptoms occur. With this research we know that it is infrasound waves that cause damage to
humans, which gives us a lead when trying to stop what is causing health problems in humans.
Possible ways of Reducing cases of Wind Turbine Syndrome:
The absolute best way of reducing the number cases that humans have right now when it comes
to IWTs is by placing them in areas where there is no or a very small human population
whenever possible. In the future, there may be other ways of reducing or eliminating the number
of infrasound waves that are emitted from IWTs. This process may be done by implementing
guidelines that must be followed by IWT developers when placing and developing IWTs.
Guidelines could include placing wind turbines outside of a certain distance away from human
populations, and/or finding a way to at least reduce the number of infrasound waves that are
emitted from wind turbines.

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