Hydrokinetic Electrical Generation Final

UNIVERSITY OF ILLINOIS AT CHICAGO
Hydrokinetic Electrical
Generation
Group 15
Lee Bode, Joseph Brown, Jonathan Richter
12/5/2014
Abstract:The goal of the project is to design a mechanical system that will generate electricity from the
kinetic motion of waves in Lake Michigan. Group 15 settled on a point absorber concept, whereby the
vertical motion of a buoy will pull a tether that will turn a generator to generate electricity, which will
then be used to power a single home. The device components were designed in SolidWorks and tested
theoretically. We determined that the cost of the components is not enough to justify the production of
a scaled down single device and is not practical. Instead, we designed one device to maximize the
power generation and efficiency for our wave geometry. We determined that the device could
potentially produce 25 kilowatts which could power over 20 homes.

Hydrokinetic Electrical Generation
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Table of Contents
Content Page Number
Introduction 2
Technical Content 3
Customer Requirements 10
Design Selection 10
Fish Bone Diagram 15
FMEA 16
GANNT 17
Ethical Considerations 18
Cost of Materials 18
Environmental Concerns 19
Calculations 19
CAD Drawings 23
Conclusion and Suggestion for Future Work 35
Acknowledgments 36

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I) Introduction
This project was proposed by the sponsor of Group 15, Dr. Ali Khounsary, who
unfortunately could not assume the typical role of a sponsor for prior obligations. As such,
Professor Brown had assumed the role of sponsor for this project. The final design selected is
a Point Absorber, a device that generates electricity from the vertical displacement by wave
motion. The beauty of hydrokinetic power generation comes from the energy transmitted to
bodies of water from the wind. Because the wind interacts with the water’s surface over a
long distance, not only is the energy to be captured dense, but it also is more consistent than
wind power because for some time after winds have died down waves will continue to
propagate.
The goal of this project is to design and test a device capable of generating electricity
from the motion of waves in Lake Michigan and then transfer that electricity to a location on
shore for power distribution. Because of time constraints and budget, we were unable to
construct a prototype and test it in actual conditions on Lake Michigan.
Group 15 was expected to design a unique device to generate electricity, but found
that a large variety of concepts were already proposed, designed, and tested already. As such,
Group 15 changed its focus from developing a completely new device to taking an existing
design concept and improving upon it based on the collective education acquired from the
University of Illinois at Chicago.
One idea that became popular in Group 15 was the idea of a “farm” of these devices.
Rather than only construct a single device to generate electricity, several smaller devices
could be implemented over an area of the lake to maximize the amount of wave energy
collected. This arrangement was also ideal due to the inconsistent flow of power coming
from each device alone. Interconnecting multiple devices can free up the cost involved in
storing energy from each device in the form of compressed air, a battery, or the use of a large
flywheel.

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II) Technical Content
Gear Train:
Pull Force Gear 1 Gear 2 Gear 3 Gear 4
N 136560 N (# of teeth) 20 15 40 24
lb 30700 d (pitchdiameter)(in) 4 3 5 3
Pd (diametrical pitch)(in-1
) 5 5 8 8
 (angularvelocity) (rpm) 197.5 263.3 263.3 438.8
(torqe) (N*m) 6937.2 5202.9 5202.9 3121.8
(torqe) (lb*in) 61399.8 46049.9 46049.9 27629.9
Rack
Velocity
m/s 1.05033 total mv (velocityratio) 2.22222
in/s 41.3515748 total mt (torque ratio) 0.45
Gear Stress Analysis:
Y (lewisformfactor) 0.35 0.3 0.39 0.36
V (vel.atPd)(FPM) 413.5 413.5 689.2 689.2
Kv (barthvel.factor) 1.3 1.3 1.6 1.6
t (tangential load)(lb) 30700 30700 18420 18420
F (face width)(in) 6.25 5.5 5 3.25
t (max bending
stress)(psi) 75483.2 75054 74358 74358
DesignSelectionMatrix Cost Safety Efficiency Performance Reliability Environment RANK
WeightingFactor 0.1 0.2 0.1 0.15 0.2 0.25
Point AbsorberBouy 9 5 3 3 7 9 6.3
Current Turbine 5 3 2 9 7 3 4.8
Attenuator 4 5 8 5 5 8 5.95
"Wave OverflowTurbine
Tank"
3 1 7 8 1 3 3.35
"Duck" Salter 1 3 9 9 9 8 6.75

Page | 4
Generator Specifics:
Generator
power 105kw
speed 375rpm
torque 2700Nm
Wave Data
Average Temperature
(DegreesC)
Average Wave Height
(Meters)
Average Wave Period
(Seconds)
Average Density
(kg/m^3)
JAN 3.85 1.2 4.2 0.999973
FEB 2.5 0.9 4.05 0.999955
MAR 2.75 0.8 3.85 0.999961
APR 2.5 0.6 3.6 0.999955
MAY 3.75 0.4 3.5 0.9999725
JUN 8 0.3 3.45 0.999849
JUL 16.5 0.4 3.5 0.99886
AUG 19.75 0.5 3.55 0.998255
SEP 17.5 0.9 3.75 0.998686
OCT 12.5 1.1 4 0.999439
NOV 8.75 1.4 4.15 0.9998
DEC 6.25 1.5 4.1 0.999933
Total 104.6 10 45.7 11.9946385
AVG 8.716666667 0.833333333 3.808333333 0.999553208
The above charts represent the design selection matrix (see Design Selection on page 9),
the force analysis of the gear system used for the device, and the characteristics of Lake
Michigan in a year
The consumption of energy per month is about 803 kilowatt-hours in an average
American home in 2012, or approximately 1.2 kilowatts. The generator selected was based on
its ability to meet this output.

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From the research conducted by Griet De Backer for his dissertation to obtain a doctorate
in civil engineering, we finalized the selection of our Buoy based on experiments specifically
done to determine the effectiveness of their shape. In their experiment, the buoys used were of
a circular shape and a conical shape. In terms of the amount of force needed to lift the buoy,
although there is no major difference in force output on the buoy, in general, the cone shaped
buoy produced larger displacements than the circular one. Based on this research, we selected
our final buoy shape to be conical.
It was determined that the final design, the point absorber, would need a concrete shell
over its mechanical systems, such as the generator and gear tram, to protect it from exposure
to water and to help weigh it down.
The final location for the device was determined to be approximately 20 kilometers off
the shore of Manistee, Michigan, specifically 44°15'00.0"N 86°35'00.0"W. The location has a
depth of approximately 200 meters, which was used as the length of the tether, and is located
near a steep rise on the lake floor.

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References
Collected By Lee Bode
"Center Research Areas." Northwest National Marine Renewable Energy Center. University of
Washington, n.d. Web. <http://depts.washington.edu/nnmrec/research.html>.
Dornfield, W. H. "Gear Tooth Strength Analysis." Stresses on Spur Gear Teeth (2004): n. pag.
Web. <www.faculty.fairfield.edu/wdornfeld/ME312/ToothLoads04.pdf>.
"High Temp Metals 800-500-2141 - PH 13-8 Mo Technical Information." High Temp Metals
800-500-2141 - PH 13-8 Mo Technical Information. N.p., n.d. Web. 03 Dec. 2014.
<http://www.hightempmetals.com/techdata/hitemp13-8MOdata.php>.
"Micro Hydro Power Water Turbine Permanent Magnet Generator (1kw-1000kw) 50hz." Micro
Hydro Power Water Turbine Permanent Magnet Generator (1kw-1000kw) 50hz.
Xinda Green Energy Co., Limited, n.d. Web. 24 Nov. 2014.
<http://www.xindaenergy.com/Micro-Hydro-Power-Water-Turbine-Permanent-
Magnet-Generator-%281kw-1000kw%29-50hz-p49.html>. Catalog of possible
generators
Nazari, Mehdi, Hassan Ghassemi, Mahmoud Ghiasi, and Mesbah Sayehbani. "Design of the
Point Absorber Wave Energy Converter for Assaluyeh Port." Iranica Journal of
Energy & Environment (2013): n. pag. Web. <http://idosi.org/ijee/4(2)13/9.pdf>.
"ProAV / Data and Information, Lists, Tables and Links." ProAV / Data and Information, Lists,
Tables and Links. N.p., n.d. Web. 05 Dec. 2014.
<http://www.bnoack.com/index.html?http&&&www.bnoack.com/data/wire-
resistance.html>.

Page | 7
Skjervheim, O., B. Sørby, and M. Molinas. Wave Energy Conversion: All Electric Power. Tech.
Brest, France: 2nd International Conference on Ocean Energy, n.d. Print.
Collected By Joseph Brown
"Application of Uni Directional Gear Drive for Wave Power Generation." Application of Uni
Directional Gear Drive for Wave Power Generation. N.p., n.d. Web. 22 Nov. 2014.
<http://www.ljindustries.com/wavepower.htm>.
Dornfield, W. H. "Gear Tooth Strength Analysis." Stresses on Spur Gear Teeth (2004): n. pag.
Web. <www.faculty.fairfield.edu/wdornfeld/ME312/ToothLoads04.pdf>.
"Grades of Wire Rope." Gabaswire, n.d. Web.
<http%3A%2F%2Fwww.gabaswire.com%2Fen%2Foverview%2Fgrades-of-wire-
rope.html>.
"How to Calculate the Wavelength of a Water Wave." EHow. Demand Media, 27 Oct. 2010.
Web. 22 Nov. 2014. <http://www.ehow.com/how_7404178_calculate-wavelength-
water-wave.html>.
Morlock, J. Shanley, and Hanes Supply, Inc. "Wire Rope." (n.d.): n. pag. Web.
Roylan. "Roylan Floats and Buoys." (n.d.): n. pag. Web.
<http://www.rolyanbuoys.com/BuoyCatalog.pdf>.
"Steel Pipes Dimensions - ANSI Schedule 80." Steel Pipes Dimensions - ANSI Schedule 80.
N.p., n.d. Web. 22 Nov. 2014. <http://www.engineeringtoolbox.com/ansi-steel-pipes-
d_306.html>.
"Synchronous Generator." - STL, SOLIDWORKS. N.p., n.d. Web. 05 Dec. 2014.
<https://grabcad.com/library/synchronous-generator>.

Page | 8
"U.S. Energy Information Administration - EIA - Independent Statistics and Analysis." U.S.
Energy Information Administration (EIA). N.p., n.d. Web. 22 Nov. 2014.
<http://www.eia.gov/state/?sid=MI#tabs-1>. For Determining the Energy consumption
in Michigan
"WIRE ROPE & CABLE Wire Rope General Purpose Rope." WebRiggingSupply. N.p., n.d.
Web. 22 Nov. 2014.
<http://www.webriggingsupply.com/pages/catalog/wirerope_cable/wirerope-
genpurprope.html>.
Collected By Jonathan Richter
"6x19 IWRC." Product Catalog. N.p., n.d. Web. <http%3A%2F%2Funionrope.com%2Fproduct-
catalog%2F6x19-IWRC>.
Backer, Griet De. Hydrodynamic Design Optimization of Wave Energy Converters Consisting of
Heaving Point Absorbers (n.d.): n. pag. Web.
<www.vliz.be/imisdocs/publications/220173.pdf>.
Budynas, Richard G., J. Keith. Nisbett, and Joseph Edward. Shigley. Shigley's Mechanical
Engineering Design. 10th ed. N.p.: n.p., n.d. Print.
Eriksson, Mikael. "Modelling and Experimental Verification of Direct Drive Wave Energy
Conversion." (2007): n. pag. Web. <www.diva-
portal.org/smash/get/diva2:169996/FULLTEXT01.pdf>.
Faizal, Mohammed, M. R. Ahmed, and Young-Ho Lee. "A Design Outline for Floating Point
Absorber Wave Energy Converters." A Design Outline for Floating Point Absorber
Wave Energy Converters. N.p., 2014. Web. 22 Nov. 2014.
<http://www.hindawi.com/journals/ame/2014/846097/>.

Page | 9
"How Hydrokinetic Energy Works." Union of Concerned Scientists. N.p., n.d. Web. 17 Oct.
2014. <http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-
energy/how-hydrokinetic-energy-works.html#.VFANa_nF-So>.
Miller, Brett A., and Stork Technimet Inc. "Failure Analysis of Wire Rope." ASM Materials
Information Redirect. N.p., 2004. Web. 22 Nov. 2014.
<http://products.asminternational.org/fach/data/fullDisplay.do?database=faco&record
=1779&trim=false>.
Rvoorhis. "Energy and the Environment-A Coastal Perspective." - Point Absorbers: The
Technology and Innovations. N.p., 25 July 2012. Web. 22 Nov. 2014.
<http://coastalenergyandenvironment.web.unc.edu/ocean-energy-generating-
technologies/wave-energy/point-absorbers/>.
"Voltage Drop Calculator." Voltage Drop Calculator. N.p., n.d. Web. 25 Nov. 2014.
<http://www.calculator.net/voltage-drop-
calculator.html?material=copper&wiresize=0.1608&voltage=400&phase=ac&noofcon
ductor=4&distance=20000&distanceunit=meters&amperes=153&x=53&y=13>.
Y. Li and Y. H. Yu: Nrel. Synthesis of Numerical Methods to Model Wave Energy Converter-
Point Absorbers: Preprint (n.d.): n. pag. National Renewable Energy Laboratory, May
2012. Web. <http://www.nrel.gov/docs/fy12osti/52115.pdf>.
Zimmermann, Kim Ann. "Lake Michigan Facts." LiveScience. TechMedia Network, 14 May
2013. Web. 01 Dec. 2014.

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III) Own Sections
i) Customer Requirements
As specified by the project proposal, the goal of this project is to design a hydrokinetic
electrical device, i.e. one that generates electricity from the motion of water, and transfer the
power to a location off shore. The total power output must be enough to power one standard
home for one year. Professor Brown added the additional requirement that the location must
be located on the Michigan side of Lake Michigan, and must have AC electrical output.
ii) Final Five Concepts
Several designs were considered for the project, each of varying levels of practicality and
effectiveness. Many other designs were considered for the process that were not included in
our Final Five Concepts, including an Oscillating Wave Surge Converter, essentially a fan
that oscillates back and forth to generate electricity from the waves. The broad scope of the
problem statement allowed for multiple possible design configurations, but eventually Group
15 settled upon these concepts:

Page | 11

Source: http://www.see.murdoch.edu.au/resources/info/Tech/tidal/
Design 1 is a Current Turbine. As one of the first designs considered, it is the most
straightforward in its function; an underwater turbine is propelled by the motion of water
currents to generate electricity. Depending on the current of a body of water, this could be one
of the more effective hydrokinetic devices. However, the turbine is one of the more dangerous
designs; if a person were to get caught in the turbine, they could be seriously injured.
Additionally, the turbine is based more on current flow than wave displacement.

Page | 12
Source: http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-
hydrokinetic-energy-works.html
Design 2 is a Point Absorber. Put simply, the point absorber is a generator that generates
electricity from the vertical motion of a buoy on the surface of water. The buoy is connected
to the generator via a tether. For our design, it was envisioned that the generator would be
placed on the floor of the body of water and sealed in a slab of concrete. The point absorber is
one of the more cost effective design choices.

Page | 13
Design 3 is an Attenuator. Attenuators are a series of interconnected cylindrical
components that rest on the surface of the water while tethered at both ends. The motion of
waves causes attenuators to “bend” and generates electricity from them. Effective attenuators
require multiple cylindrical components to maximize electricity generation.
Design 4 is the Overtopping Device, also called the “wave overflow turbine tank.” Unlike
the other designs, this one is a shore based turbine that collects waves that arrive on a coast.
Water flows in through the top and flows down, turning a large turbine. From there, the water
is filtered out back towards the body of water.

Page | 14
Source: http://www.mech.ed.ac.uk/research/wavepower/
Design 5 is based off the “Salter’s Duck” prototype device by Stephen Salter. The device
was in its experimental stages in the 1970s before being discontinued. The Duck filters waves
and extracts the maximum amount of energy from them, more so than any other design
conceived. Unfortunately, very few design schematics could be found, and those that were
found proved to be undescriptive about the prototype and the few pictures found presented a
device that was too complex to be created within the scope of this course.
Ultimately, Group 15 voted unanimously in favor of the Point Absorber concept. Our
group concluded that certain devices, particularly the Overtopping Device and Salter’s Duck ,
were simply beyond the scope of this course, and could not be designed from scratch within
the three months of time for this course. The turbine design had potential, but was concluded
to be impractical for the farm concept that we had in mind for a device of its size; the
propeller would be hazardous to any aquatic life or swimmer who would get too close, and
fixing this problem would require a net over a large area of the lake, which is neither practical
nor completely safe for wildlife.
In favor of the Point Absorber concept, it is simple to build, design, and execute in
practice. Several point absorbers could be used in the farm concept to maximize the amount
of wave energy collected, provided that they spaced apart correctly.

Page | 15
iii) Fish Bone Diagram and FMEA Chart

Page | 16

Page | 17
iv) GANNT

Page | 18
v) Ethical Considerations
Safety is of utmost concern to this project. The device must not be designed in such a
way as to cause harm to any human being. A proposed way to avoid any collisions with
boats is to add the standard warning features to the buoy component of the design,
including reflective tape and warning lights in addition to the bright coloring of buoy.
The tether is a potential hazard to swimmers, but considering that it is located 20
kilometers off shore, it is unlikely to come into contact with casual swimmers.
vi) Cost of Materials
Component Manufacturer Cost
PPMB-12 Mooring Buoy Urethane Technologies,Inc. $500 (estimated)
Micro Hydro PowerWater
Turbine PermanentMagnet
Generator(105 kw)
XindaGreenEnergyCo.,
Limited
$10000 (estimated)
6X19 EXTRA IMPROVEDPLOW
STEEL, RIGHT REGULAR LAY 1”
WebRiggingSupply $2526 ($3.85 perfootat
approximately200 metersor 656
feet)
PortlandCementType II PortlandCementAssociation Approximately$4500
Gear System(PH13-8 Stainless
Steel)
Notes:
- After several attempts to contact Xinda Green Energy Co., we received no response from
them. The value for their generator was estimated. The same applies for the mooring
buoy
- Concrete density was estimated to be approximately 150 pounds per square foot from
information provided by Paul D. Tennis, Director of Product Standards and Technology
of Portland Cement Association. The cost of cement varies, so the cost was estimated at
$90 per cubic foot. The amount of concrete decided as necessary was determined by the
total expected upward force on the tether multiplied by four; the concrete needed must be
enough to weigh it down by that much.

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vii) Environmental Concerns
The Environmental impact was a concern during the design selection phase, and
ultimately led to the rejection of Design 1, the Current Turbine. Lake Michigan is home to
several species of fish, many of which could go into the path of the device. The Point
absorber was determined to be the most environmentally friendly device, based on its lack of
potential threats to wildlife; although the tether could be a potential threat, it is largely
negligible
viii) Calculations
Note: The tether was assumed to be a single solid cylinder with a diameter of 1” subjected to
static loading for simplicity. The tether selected is capable of enduring of the forces indefinitely.
To equate the maximum upward pull we utilized the full buoy’s buoyancy as if it were to fully
submerge in order to allow us to utilize this force for stress analysis.
Buoy buoyancy – Buoy weight – Tether weight = Maximum upward pull force
37,600lb – 5700lb – 1214lb = 30700lb = 136,560 N
Velocity of buoy:
Average Amplitude= 2 meters
Average Period = 3.80833 seconds
½ Period (from lowest to highest peak) = 1.90417 seconds
𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦 =
2𝑚
1.90417𝑠
= 1.05033
𝑚
𝑠
Tether:
F=31500 lbs.

Page | 20
L=657 ft.
D=1”
𝜎𝑥 =
𝐹
𝐴
=
31500
𝜋 ∗
12
4
= 40,107 𝑙𝑏/𝑖𝑛2
Break strength of Tether: 103,400 lb.
Cement:
F (buoyancy)=31500 lbs.
F (generator)=2778 lbs.
𝜌( 𝑐𝑒𝑚𝑒𝑛𝑡) = 150 𝑙𝑏𝑠/𝑓𝑡3
𝜌( 𝑤𝑎𝑡𝑒𝑟) = 62.4 𝑙𝑏𝑠/𝑓𝑡3
4 ∗
31500 − 2778
150 − 62.4
≈ 1350 𝑓𝑡3
𝑜𝑓 𝑐𝑜𝑛𝑐𝑟𝑒𝑡𝑒

Page | 21
Gear Train Analysis:
To design and analyze the gear train the following variables and equations were used.
Variable Description (Units)
𝑃 𝑑 Diametrical Pitch (in-1)
𝑚 𝑉 Velocity Ratio
𝑚 𝑇 Torque Ratio
P Maximum upward pull force (N)
𝜔 Angular Velocity (rpm)
r Radius (in)
Y Lewis form factor
Kv Barth velocity factor (FPM)
Wt Tangential load (lb)
F Face width (in)
t Maximum bending stress (psi)
V Velocity (FPM)
𝑃𝑑 = 𝑁
𝑑⁄ 𝑚 𝑉 =
𝑁1∙𝑁3
𝑁2∙𝑁4
𝑚 𝑇 =
1
𝑚 𝑣
𝜔𝑖𝑛 =
𝜔 𝑜𝑢𝑡∙𝑟 𝑜𝑢𝑡
𝑟𝑖𝑛
𝜏 = 𝐹 ∙
𝑑
2

 𝜎𝑡 =
𝑊𝑡∙𝑃 𝑑
𝐹∙𝑌
∙ 𝐾𝑣 𝐾𝑣 =
1200+𝑉
1200


Page | 22
Electrical loss:
I=153 amps
L=20,000 meters
Cross sectional area of wire=500 mm2
ρ=electrical resistivity= 0.01724 Ω*mm2/m (for copper)
Voltage output = 400 Volts
∆𝑉 = 𝑉𝑜𝑙𝑡𝑎𝑔𝑒 𝑑𝑟𝑜𝑝 = 𝐼 ∗
2 ∗ 𝐿 ∗ 𝜌
𝐴
= 153 ∗
2 ∗ 20000 ∗ 0.01724
500
= 211.018
Voltage Drop:
∆𝑉
𝑉𝑜𝑢𝑡𝑝𝑢𝑡
=
211.018
400
≈ 53%
Rough estimate:

Page | 23
ix) CAD Drawings (made in SolidWorks)

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Final Assembled Device

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IV) Conclusion & Suggestions for Future Work
Due to time and budget constraints, as well as commitments to employment and UIC
classes, team 15 was unable to construct or physically test the final design, although
significant effort was done to theoretically determine its viability.
After several attempts of designing the device, we determined that designing a single
device to power one house simply wasn’t efficient. Even if a different device was chose, the
consistency of the power generated would not justify a single device based in Lake Michigan
due to the added cost of storing the intermittent power. Ultimately, the cost per power output
ratio when comparing a much scaled down device is enormous compared to a device scaled
more to the size of the lakes wave geometry.
Another point in favor of a farm of devices is that when multiple are in operation this
allows the power transmission to the shore to be interconnected into a much thicker industrial
size transmission cable. This is extremely ideal due to the 100% power loss in the thickest
(.46in diameter AWG 0000 4/0) commonly listed cable over our 20km distance. Using a
19.685in diameter AWG 1000MCM cable results in just over 50% voltage drop. This is the
thickest cable we could find is typically used for power plant scale power transmission. Since
the waves are upstroke only half the time, the generator only generates half of its max power
(52.5 kW). Accounting for the losses, this will give a net power output of 24.675 kilowatts.
Based on the average power consumption in the United States, this device could potentially
power up to 20 households.
One potential means of improving the device is to implement a means of adjusting the
length of the tether. One noticeable problem from the design was its inability to adjust length
depending on the time of the year; the device was designed with the average wave
displacement in mind, not accounting for different times of the year when wave displacements
would vary. As such, introducing a manual means of extending the tether could prove
beneficial for maximizing the electricity generated. It was also proposed that simply
extending the height of the device, and with it the rack, would alleviate the problem with the
changing wave heights over the year.

Page | 36
V) Acknowledgments:
Special Thanks to Professor Michael Brown for assuming the role of Project Sponsor for
this project
Special Thanks to Professor Jamison L. Szwalek as our Technical Advisor

Hydrokinetic Electrical Generation Final

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