Microwind Alternative Energy and the Wind

Belt

Thesis DefenseEric Myers

Introduction

Goals of the Research Recreate the original prototype of the windbelt generator Maximize the output voltage Design an improved version of the windbelt

Questions to be answered.

1. What is a windbelt generator?

2. Why choose the windbelt?• Cheap

• Easy to build

• Able to operate under low wind speeds

3. What are the other options?• Micro-wind turbine

• Wind turbine

4. Why not choose the turbine?

5. How does the windbelt work?

Popular Mechanics – 2007 Breakthrough Award

Shawn Frayne

Working in Haiti, Shawn Frayne, a 28-year-old inventor based in Mountain View, Calif., saw the need for small-scale wind power to juice LED lamps and radios in the homes of the poor. Conventional wind turbines don’t scale down well—there’s too much friction in the gearbox and other components. “With rotary power, there’s nothing out there that generates under 50 watts,” Frayne says. So he took a new tack, studying the way vibrations caused by the wind led to the collapse in 1940 of Washington’s Tacoma Narrows Bridge (aka Galloping Gertie). Frayne’s device, which he calls a Windbelt, is a taut membrane fitted with a pair of magnets that oscillate between metal coils. Prototypes have generated 40 milliwatts in 10-mph slivers of wind, making his device 10 to 30 times as efficient as the best microturbines. WEB

Coil

Magnet LED

Moving Belt

One of the advantages of the windbelt is it’s simple design.

Frame

Windbelt 4-14 mph About 40 mW per device $20

Wind Turbine 15-35 mph 400 Watt at 28 mph $725

A 2005 Stanford University study found that there is enough wind power worldwide to satisfy global

demand 7 times over — even if only 20% of wind power could be captured.

Aeroelastic Flutter and the Wind Belt

Cheap Generator Alternative, Set to Power Third World

Aeroelastic Flutter

Flutter is a self-starting and potentially destructive vibration where aerodynamic forces on an object couple with a structure's natural mode of vibration to produce rapid periodic motion.

Flutter is a self-starting and potentially destructive vibrationpotentially destructive vibration where aerodynamic forces on an object couple with a structure's natural mode of vibration to produce rapid periodic motion.

DEMO

Large Scale Applications

Rural Electricity

Powering Small Devices

WiFiRouter

WiFiRouter

Lighting

HVAC Temp Sensor Air Quality

Sensor

Stress Monitor Sensor

Belt Materials Ribbon 35mm Film Tape Mylar Mylar Coated Taffeta

Coil Making Eric Video Nathan Shawn

0

100

200

300

400

500

600

700

800

0 5 10 15 20 25 30 35 40 45 50

Magnet Posiiton (cm)

Ou

tpu

t V

olt

age

(mV

)

Strobe

Rotation - Strobe

Back and Forth - Strobe

Magnet Strength

5

2

r

rmrrm3

4B

Magnetic Field

Dipole Moment

Distance from Magnet

5

2

r

rmrrm3

4B

5

2

r

rmrrm3

4B

zmm zzr

zz

1

4

m2B

3

3z

1

4

m2B

How do you measure the strength of the magnet?

Magnetometer

0

5

10

15

20

25

30

0 2 4 6 8 10 12 14

Distance (cm)

Mag

net

ic F

ield

(m

T)

Is this a inverse cube relationship?

3z

1

4

m2B

bmxy

0

5

10

15

20

25

30

0 20000 40000 60000 80000 100000 120000

Distance-3 (cm-3)

Mag

net

ic F

ield

(m

T)

y = 2.35E-04x

0

5

10

15

20

25

30

0 20000 40000 60000 80000 100000 120000

Distance-3 (cm-3)

Mag

net

ic F

ield

(m

T)

34 cmmT1035.24

m2slope

3z

1

4

m2B

34 cmmT1035.2 2 m4

slope

2mA05.1m

Magnetic Moment

Output VoltageCalculation

Output Voltage

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0 2 4 6 8 10 12 14 16 18 20

wt (rad)

E (

V)

S

adBFlux

EMF

t

Michael Faraday

S

adB

m

x

y

z

R

tsinAdzm w

zzzˆr m

zmm

dazad ddda

z

r

rmrrm3

4zB

5

2

2

52m

2

2m

22m

z

zmmz3

4zB

Cylindrical Symmetry

R

0

2

0 2

52m

2

2m

22m

S

ddz

zmmz3

4dazB

R

0 2

32m

2

R

0 2

52m

2

2m

z

dm

z

dmz32

4

2m

2

2m

2m

2

2m

zR

z 2

3

zR

z 2

5

2m du

u

1

2

mdu

u

1

2

mz3

2

2m

2

2m

2m

2

2m

zR

z2

1

zR

z2

32m

u

1m

u

1mz

2

2

12m

2

12m

22

32m

2

32m

2

2m

z

1

zR

1m

z

1

zR

1mz

2

2

32m

2

2m

2

12m

2 zR

z

zR

1

2

m

2

32m

2

2

zR

R

2

m

t

t

2522

2

tsinAdR2

tcosAmR3

w

ww

2

32m

22

zRt2

mR

tzt

2zR2

3

2

mRm

2

52m

22

Output Voltage

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0 2 4 6 8 10 12 14 16 18 20

wt (rad)

E (

V)

2522

2

tsinAdR2

tcosAmR3

w

ww

2

322

2 cossinsin

2zR

ttmR www

2522

2

tsinAdR2

tcosAmR3

w

ww

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0 2 4 6 8 10 12 14 16 18 20

wt (radians)

EM

F (

Vo

lts)

Up and Down

Rotation

0

0

-0.02

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

0.02

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04

Time

EM

F

x

y

z

R

x

y

z

R

x

y

z

R

x

y

z

R

Good

ChaoticNothing

Fair

x

y

z

R

x

y

z

R

x

y

z

R

x

y

z

R

Good

ChaoticNothing

Fair

x

y

z

R

Best?

New Design

Higher Current

Higher Voltage

Acknowledgements

Dr. Bruton Dr. Trikosko Izzy Silver Nathan Ellis Alejandro Villalobos Brain McGrail

References

“Electricity and Magnetism”

-Wayne Saslow

“Windbelt, Cheap Generator Alternative, Set to Power Third World”

-Shawn Frayne, www.humdingerwind.com

Goals No specialized materials

• Can be used in developing countries

Weatherproof a Windbelt Array

Aeroelastic Flutter

and the Wind Belt

Thesis DefenseEric Myers