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.


Table of Contents

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

Page | 1


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.

Page | 2


II) Technical Content

Gear Train:

Pull Force Gear 1 Gear 2 Gear 3 Gear 4N 136560 N (# of teeth) 20 15 40 24lb 30700 d (pitch diameter)(in) 4 3 5 3

Pd (diametrical pitch)(in-

1) 5 5 8 8 (angular velocity)

(rpm) 197.5 263.3 263.3 438.8(torqe) (N*m) 6937.2 5202.9 5202.9 3121.8

(torqe) (lb*in)61399.

846049.

946049.

927629.

9Rack Velocity

m/s 1.05033 total mv (velocity ratio)

2.22222

in/s 41.3515748 total mt (torque ratio) 0.45

Gear Stress Analysis:

Y (lewis form factor) 0.35 0.3 0.39 0.36

V (vel. at Pd)(FPM) 413.5 413.5 689.2 689.2

Kv (barth vel. factor) 1.3 1.3 1.6 1.6

Page | 3

Design Selection Matrix Cost Safety Efficiency Performance

Reliability Environment RANK

Weighting Factor 0.1 0.2 0.1 0.15 0.2 0.25Point Absorber Bouy 9 5 3 3 7 9 6.3Current Turbine 5 3 2 9 7 3 4.8Attenuator 4 5 8 5 5 8 5.95"Wave Overflow Turbine Tank" 3 1 7 8 1 3 3.35

"Duck" Salter 1 3 9 9 9 8 6.75


t (tangential load)(lb) 30700 30700 18420 18420F (face width)(in) 6.25 5.5 5 3.25

t (max bending stress)(psi)

75483.2 75054 74358 74358

Generator Specifics:

Generatorpower 105kwspeed 375rpmtorque 2700Nm

Wave Data

Average Temperature (Degrees C)

Average Wave Height (Meters)

Average Wave Period (Seconds)

Average Density (kg/m^3)

JAN 3.85 1.2 4.2 0.999973FEB 2.5 0.9 4.05 0.999955

MAR 2.75 0.8 3.85 0.999961APR 2.5 0.6 3.6 0.999955

MAY 3.75 0.4 3.5 0.9999725JUN 8 0.3 3.45 0.999849

JUL 16.5 0.4 3.5 0.99886AUG 19.75 0.5 3.55 0.998255

SEP 17.5 0.9 3.75 0.998686OCT 12.5 1.1 4 0.999439

NOV 8.75 1.4 4.15 0.9998DEC 6.25 1.5 4.1 0.999933Total 104.6 10 45.7 11.9946385

AVG 8.716666667 0.833333333 3.808333333 0.999553208

Page | 4


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.

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.

Page | 5


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>.

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.

Page | 6


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>.

"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

Page | 7


"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/>.

"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>.

Page | 8


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&noofconductor=4&dista

nce=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.

Page | 9


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 | 10


\

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 | 11


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 | 12



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 | 13


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 | 14


iii) Fish Bone Diagram and FMEA Chart

Page | 15


Page | 16


iv) GANNT

Page | 17


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 CostPPMB-12 Mooring Buoy Urethane Technologies, Inc. $500 (estimated)Micro Hydro Power Water Turbine Permanent Magnet Generator (105 kw)

Xinda Green Energy Co., Limited

$10000 (estimated)

6X19 EXTRA IMPROVED PLOW STEEL, RIGHT REGULAR LAY 1”

Web Rigging Supply $2526 ($3.85 per foot at approximately 200 meters or 656 feet)

Portland Cement Type II Portland Cement Association Approximately $4500Gear 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.

Page | 18


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

37,600 lb – 5700lb – 1214 lb=30700 lb=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= 2 m1.90417 s

=1.05033 ms

Tether:

F=31500 lbs.

Page | 19


L=657 ft.

D=1”

σ x=FA

=31500π∗12

4

=40,107 lb /¿2

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∗31500−2778150−62.4

≈ 1350 ft3 of concrete

Page | 20


Gear Train Analysis:

To design and analyze the gear train the following variables and equations were used.

Variable

Description (Units)

Pd Diametrical Pitch (in-1)mV Velocity RatiomT Torque RatioP Maximum upward pull force (N)ω Angular Velocity (rpm)r Radius (in)Y Lewis form factorKv Barth velocity factor (FPM)Wt Tangential load (lb)F Face width (in)t Maximum bending stress (psi)V Velocity (FPM)

Pd=Nd

mV =N 1 ∙ N 3

N2 ∙ N 4

mT=1

m vω¿=

ωout ∙ rout

r¿

τ=F ∙ d2

σ t=W t ∙ Pd

F ∙Y∙ K v K v=

1200+V1200

Page | 21


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∗ρA

=153∗2∗20000∗0.01724500

=211.018

Voltage Drop:

∆VV output

=211.018400

≈ 53 %

Rough estimate:

Page | 22


ix) CAD Drawings (made in SolidWorks)

Page | 23


Page | 24


Page | 25


Page | 26


Page | 27


Page | 28


Page | 29


Page | 30


Page | 31


Page | 32


Final Assembled Device

Page | 33


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 | 34


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

Page | 35

hydrokinetic electrical generation final

Documents