The Electric Boat Challenge:

Is Solar Power Better than Gasoline Power?

Or does H2 Work Best?

Dr. Andrew Zborowski, Ph.D.and Frank R. Leslie, BSEE, MS Space Technology

1/14/2005

1. Abstract• Identical trolling

motors• Similar hulls• Identical batteries• Differing energy

sources• What is to be

demonstrated?

What speeds and distances result from solar & gasoline, etc. sources?

AbstractSolar

Gasoline

2. Hull Forces• Drag force is

proportional to speed squared

• Drag force is balanced by motor force resulting in equilibrium speed

• Different hull shapes result in different maximum speeds

Speed limited by forces

Hull Forces

Fh = k • S2

Fm = Fh

Fm Fh

Moving this way -->

3. Motor Thrust• Measure thrust force

with “open water” around prop (bollard test)

• Plot relationships• Compare motors• Specification of 30

pounds thrust

What is “best” load?

Motor Thrust

Fm

Load Resistance

Force,Current

Voltage

4. Travel Energy• Energy =

Power • time• E = P • t• Define race end• Define time &

distance V = d/t

What energy is required?

Travel Energy

Distance, d

5. Energy Storage• Battery depletion rate• Are batteries truly

identical?• Full charge at 12.80

volts (TBR; to be reviewed)

• Discharge load of motor affects available ampere-hours

• Stop at 10.5V to preserve battery life Trade power vs. energy

Energy Storage

10.5 V

Voltage, E

Time, t

= ?

6a. Energy Sources• Internal Combustion

Engine (ICE) burning gasoline and oil mix charges battery– Requires fuel

• Solar Panel charges battery– Requires sun

What else to use?

Energy Sources

Solar or PV

Gasoline ICE

Gasoline

Crudeoil

6b. Energy Sources• Fuel Cell

– Hydrogen & air in

– Water & Electricity out

– ~12Vdc; 1000 watts

• Leslie’s Pedal Cycle – Requires food in

– Biomass to mechanical to electrical energy

– 14 volts @ 6 amps charges battery

Which to use?

Energy Sources

Pedal Cycle

Hydrogen Fuel Cell

Hydrogen

FuelCell

12Vdc

7. Race Conditions• Ready to race?

– Good weather

– Calm water

– Wind below 4 knots

– Batteries charged

– Known weight

– Straight, sheltered course

– Side-by-side start

– End defined by battery voltage less than 10.5 volts per digital multimeter or H2 tank empty

Perhaps a little slower

Race Conditions

8. Potential Conclusions and Findings

• Match results against theory– Explain discrepancies

• Data analysis shows that . . . ?

• Recommendations for the following classes --- “Lessons Learned”

• Create report and present results

What’s next?

Potential Conclusions and Findings