Affordable Wind Turbines for Energy Poverty Alleviation

IEEE Global Humanitarian Technology Conference Tutorial Session

30 October 2011 Seattle, WA

Dr. Henry Louie

Seattle University

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Agenda

• Case Study: Zambia • The Market • The Technology • Field Notes • Lessons Learned • Next Steps

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ZAMBIA

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Zambia +12 million people

• 25% have electricity • per capital energy use: 3.3% of USA

+8 million live in rural communities • 4% have access to electricity • 50% of rural population have electronic devices

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Case Study: Zambia 8

The Market for Electricity • Cell Phone Charging: With charger: 1000 Kwacha (US$ 0.20) With shop charger: 1500 Kwacha (US$ 0.30)

• Car Battery Charging: 2500 Kwacha (US$ 0.50) Charged overnight

• LI cellular phone battery capacity: 5 Wh Cost per Wh: US$ 0.04

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Back-of-envelope calculation: • Village size: 1000 people • Percent with cellular phones: 15 • Charge Frequency: 1/week • Charges per day: 21 • Energy required: 105 Wh per day • Wind turbine capacity factor: 15% • Wind turbine size: 30 W • Income: US$4.20/day • Payback time on $500 investment: 120 days

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Appropriate Technology Wind Turbines

• Open-source design • Support social businesses Manufacturer Service Merchant power producer

• Made in-country • Common and accessible

materials • Simple techniques

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Appropriate Technology Wind Turbines

Advantages • Manufacturability

– Simple tools – Simple process – Material availability

• Mechanical – Can be easily repaired – Intuitive design

• Supports social buisness • Renewable energy source

Disadvantages • Tower structure required • Site assessment difficult • Intermittency • Rare earth magnets • Maintenance • AC/DC conversion • Battery system

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Approach • Start with existing Do-It-Yourself wind turbine

design • Build prototypes in Seattle • Assess feasibility and field test in rural

community • Redesign, refine and retest

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Appropriate Technology Wind Turbine

• Axial Flux • Permanent Magnet (NdFeB) • Dual Rotor • 12-Pole • Direct Drive • Synchronous • Three Phase • 5 foot blades • Based on design in Homebrew Wind Power

(www.otherpower.com)

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Generator made in Seattle Blades, Tower, made in Zambia

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magnets

coils

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Simulated Power Output

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0 50 100 150 200 250 300 3500

200

400

600

800

1000

Mechanical Frequency (RPM)

Pow

er (W

)

0 50 100 150 200 250 300 3500

200

400

600

800

1000

Mechanical Frequency (RPM)

Pow

er (W

)

24 V Battery 12 V Battery

Cut-in

N

N

N N

N

N S

S

S

S

S

S

Rare earth magnets

Resin

Second rotor is duplicate of first

terminals

Three phase wye 14 AWG enameled wire

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rotors

stator

hub

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ZAMBIA

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X Chikuni

Lusaka

Livingstone

230 miles

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anemometer

100

inch

es

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X 450 ft

Wind turbine location

Prevailing Wind

Wind Speed Measurements

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0 5 10 15 20 250

2

4

6

8

10

12

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15-minute average wind speed (mph)

occu

rrenc

es

0 5 10 15 20 250

2

4

6

8

10

12

14

15-minute max wind speed (mph)

occu

rrenc

es

Maximum Values Average Values

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100 inches

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4 foot blades vs. 5 foot blades

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312

ρ= pAP C v

5 ft

4 ft

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Generator

Blades

Hub

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Generator assembly

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cows

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http://www.youtube.com/watch?v=1qv4B7zy08w

Wind Speed Measurements (During Field Testing)

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0 5 10 15 20 250

2

4

6

8

10

12

14

instantaneous wind speed (mph)

occu

rrenc

es

Instantaneous Values

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Furled Position Facing into the Wind

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Va Vb

Vc n

Generator

short to stop turbine

+

- 12V battery

switch

3-Phase Rectifier

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http://www.youtube.com/watch?v=faBwLgE4NE0

Wind Speed vs. RPM

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0 5 10 15 20 250

50

100

150

200

250

300

350

instantaneous wind speed (mph)

RPMLarge variation due to inertia of blades

Efficiency and Tip Speed Ratio

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Cp

1 2 3 4 5 6 7 8 0

0.6

0.2

0.4

TSR

TSR between 5 and 7 is considered good

Wind Speed vs. TSR

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0 5 10 15 20 250

1

2

3

4

5

6

instantaneous wind speed (mph)

TSR

Very low TSR, efficiency

Reshaping the Blades

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Inefficient Leading Edge

Reshaped Leading Edge

Wind Speed vs. RPM

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0 5 10 15 20 250

50

100

150

200

250

300

350

instantaneous wind speed (mph)

RPM

Wind Speed vs. TSR

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0 5 10 15 20 250

1

2

3

4

5

6

instantaneous wind speed (mph)

TSR

Improved TSR, efficiency

Performance Data

• Volts per Hz Measured: 1.07

• Cut-in RPM (12 V battery) Measured: 85 RPM

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Performance Data

• Idle Speed: 11 mph • Cut-in (battery charging): 15 mph • Max RPM tested: 330 • Maximum instantaneous power output: 75 W • Continuous power output: 5 W • Blades were wrong size for generator

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700W Wind Turbine Costs • Pipe: $78 • Wood: $13 • Wire: $0.32/m x 250m = $80 • Magnets*: 24 x $15 = $360 • Resin*: $80 • Hardware*: $130 • Rectifier*: $7 • Battery: $125 • Metal Parts*: $450 • Electrical*: $20

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* Price in the U.S.

Total: US $1343

Cost Considerations

• Does not include tools, labor • Price of rare earth magnets increasing and

volatile • Magnets not easy to find • Wind turbine is too big, expensive • Micro loans generally are $500 or less

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Lessons Learned • Very location dependent Best energy source Prices/availability Expertise Economics Tower

• Most components can be found locally, prices are usually more expensive than in U.S.

• Feasibility of blade and tower construction

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Future Plans • Design 100 W wind turbine • Engineer safe, secure tower solution • Work with local community • Promote as a business opportunity

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0.00 5.00 10.00 15.00 20.00 25.00 30.00Time [ms]

-20.00

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

20.00

Y1

[V]

0.00

25.00

50.00

75.00

100.00

125.00

Mov

ing1

.Pos

ition

[deg

]

Maxwell3DDesign2XY Plot 1 ANSOFT

Curve Info Y AxisMoving1.Position Moving1.Position

InducedVoltage(A_Phase) Y1

InducedVoltage(B_Phase) Y1

InducedVoltage(C_Phase) Y1

Acknowledgements • Fr. Bert Otten, S.J. • Steve Szablya, PE • Ayesha Pirbhai • Josh Peavler • Karim Farraj • Byron Lynch • Carmen Cejudo • Dino Go

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Chikuni Jesuit Mission

Questions? 63

References [1] H. Louie and S. J. Szablya “Electromagnetic Field Modeling of

Appropriate Technology Generators for Rural Electrification Applications,” IEEE Global Humanitarian Technology Conference, Seattle, WA, Oct. 2011.

[2] R. Podmore, R. Larsen, H. Louie and B. Waldron “Affordable Energy

Solutions for Developing Communities,” In Proceedings of the IEEE Power & Energy Society General Meeting, Detroit, MI, Jul. 2011.

[3] H. Louie “Experiences in the Construction of Open Source Low

Technology Off-Grid Wind Turbines,” In Proceedings of the IEEE Power & Energy Society General Meeting, Detroit, MI, Jul. 2011.

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Learn More

• www.communitysolutionsinitiative.org/ • www.drhenrylouie.com

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@henrylouie

S C I E N C E A N D E N G I N E E R I N G

Henry Louie, PhD Assistant Professor

Department of Electrical and Computer Engineering 901 12th Avenue, Bannan 219 P.O. Box 222000 Seattle, WA 98122-1090 www.seattleu.edu

Tel: (206) 398-4619 Fax: (206) 296-5962 louieh@seattleu.edu

COLLEGE OF

Videos • http://www.youtube.com/watch?v=7ze9DSB7dRA • Raising The Turbine in Chikuni, Zambia(255.5M) • http://www.youtube.com/watch?v=6qOQk6gl7O8 • Wind Turbine and Electrical Setup in Chikuni, Zambia(27.1M) • http://www.youtube.com/watch?v=EO38Mo_WJdk • The Wind Turbine Spinning in Chikuni, Zambia(57.87M) • http://www.youtube.com/watch?v=OQ9U7uz8onk • Electric Braking During High Speed Operation in Chikuni, Zambia(59.45M) • http://www.youtube.com/watch?v=faBwLgE4NE0 • Alternate View of the Turbine Configuration from the bottom of Dam in

Chikuni, Zambia(53.72M) • http://www.youtube.com/watch?v=1qv4B7zy08w

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