Solar Powered Solar Powered TrikeTrikeDavid PearceDavid Pearce

Energy and the EnvironmentEnergy and the Environment

Professor Reza ToossiProfessor Reza Toossi

Objective: Objective:

Build a green vehicle that runs for free Build a green vehicle that runs for free purely off of the sun’s energypurely off of the sun’s energy

Eliminate the need to drive everywhere, Eliminate the need to drive everywhere, especially short trips.especially short trips.

Promote the usage of green alternative Promote the usage of green alternative energiesenergies

Performance GoalsPerformance Goals

The solar panels must fully charge the The solar panels must fully charge the batteries in a practical amount of time, batteries in a practical amount of time, similar to that of a plug in charger.similar to that of a plug in charger.

The vehicle must be legal to ride on the The vehicle must be legal to ride on the street.street.

The pedaling function must remain The pedaling function must remain unmodifiedunmodified

Must be emission freeMust be emission free

DesignDesign

Simple 3 wheeler, battery poweredSimple 3 wheeler, battery powered High efficiency mono-crystalline solar panels to High efficiency mono-crystalline solar panels to

charge batteries charge batteries Baskets provide for batteries, storage and solar Baskets provide for batteries, storage and solar

panel mountspanel mounts 36V, 700 Watt peak Brushless Hub motor 36V, 700 Watt peak Brushless Hub motor

integrated in front wheel, kit w / all components integrated in front wheel, kit w / all components including 110V-36V charger/ transformerincluding 110V-36V charger/ transformer

Minimal modifications to trikeMinimal modifications to trike

Calculations: BatteriesCalculations: Batteries

3-12 volt 20 Amp/hour batteries in series3-12 volt 20 Amp/hour batteries in series =36V and 20 A/hr,=36V and 20 A/hr, P =(36V*20A/hr)P =(36V*20A/hr)

= 720 Watt/hr battery capacity= 720 Watt/hr battery capacity

Battery choice was determined by capacity, price, Battery choice was determined by capacity, price, and weight.and weight.

Bigger batteries= Longer range, but longer Bigger batteries= Longer range, but longer charge times, more money and more weight.charge times, more money and more weight.

Calculations: Solar panelsCalculations: Solar panels

3-22V Solar panels in series = 66V3-22V Solar panels in series = 66V 1.2+ Amp current each panel1.2+ Amp current each panel Ohm’s Law P=(V*I)Ohm’s Law P=(V*I) P=(66V*1.2A) = 80 Watts provided by solar panelsP=(66V*1.2A) = 80 Watts provided by solar panels Theoretical charge time:Theoretical charge time: House hold current charges with constant wattage at a maximum House hold current charges with constant wattage at a maximum

rate of 1.5 A, takes 6-8 hrs to fully charge from rate of 1.5 A, takes 6-8 hrs to fully charge from full discharge full discharge voltage of 32V.voltage of 32V.

Solar Panels charge at 1.2+ amps, slightly slower, but equivalent Solar Panels charge at 1.2+ amps, slightly slower, but equivalent in charging speed if batteries are kept from fully discharging, in charging speed if batteries are kept from fully discharging, above an experimentally determined cut-off voltage.above an experimentally determined cut-off voltage.

Calculations: MotorCalculations: Motor

3 Phase Brushless motor, 700 Watts peak, 500 Watts RMS, 3 Phase Brushless motor, 700 Watts peak, 500 Watts RMS, 265 rpm ( no load)265 rpm ( no load)

Theoretical top speed:Theoretical top speed: : : 265rev | 60 min | (2)*(3.14)*(13”) rad | 1 ft | mile 265rev | 60 min | (2)*(3.14)*(13”) rad | 1 ft | mile min | hr | revolution | 12” | 5,280 ftmin | hr | revolution | 12” | 5,280 ft

= 20.5 mph top speed= 20.5 mph top speed

Theoretical range:Theoretical range: : : 20.5 miles | hr | 500 Watts RMS20.5 miles | hr | 500 Watts RMS hr | 720 Watts | hr | 720 Watts |

= 14.2 mile range= 14.2 mile range

Calculations: Charging Calculations: Charging systemsystem

A solar charge converter is needed to steadily and A solar charge converter is needed to steadily and efficiently charge the batteries with the varying input efficiently charge the batteries with the varying input power of the solar panels.power of the solar panels.

A Maximum Power Point Tracking type solar charge A Maximum Power Point Tracking type solar charge

controller was chosen for it’s high efficiency, and ability to controller was chosen for it’s high efficiency, and ability to run the panels at their peak output when conditions allow, run the panels at their peak output when conditions allow, which shortens charging time.which shortens charging time.

SpecificationsSpecificationsInput range: 0-100VInput range: 0-100VOutput: 42.4VOutput: 42.4VCharging method: constant wattage Charging method: constant wattage • (P=constant, as voltage goes up current goes down)(P=constant, as voltage goes up current goes down)

Testing / AnalysisTesting / Analysis

Testing showed that in order to charge the Testing showed that in order to charge the batteries in a practical amount of time, the batteries in a practical amount of time, the experimentally determined cut-off voltage experimentally determined cut-off voltage needed was found to be around 36V. Thus needed was found to be around 36V. Thus voltage must not drop below 36 V (12V each voltage must not drop below 36 V (12V each battery), as inferred from the calculations, and battery), as inferred from the calculations, and the panels will charge at an equivalent rate to the panels will charge at an equivalent rate to the household plug-in charger.the household plug-in charger.

This limits the range to around 10 miles, but This limits the range to around 10 miles, but longer trips can be made at the expense of longer trips can be made at the expense of charging time.charging time.

PerformancePerformance

The Solar panels charge the batteries in The Solar panels charge the batteries in an adequate amount of time.an adequate amount of time.

10+ mile range10+ mile range 18 MPH18 MPH Climbs hills with pedalingClimbs hills with pedaling

Conclusion:Conclusion:

Solar energy is a viable source of power for a personal transport Solar energy is a viable source of power for a personal transport vehicle, and has great potential as photovoltaic technology vehicle, and has great potential as photovoltaic technology evolves.evolves.

Record high gas prices and excessive greenhouse gas emissions Record high gas prices and excessive greenhouse gas emissions are creating a market for green alternatives to fossil fuel based are creating a market for green alternatives to fossil fuel based transportation, such as the Solar Powered Trike.transportation, such as the Solar Powered Trike.

Total cost : $910Total cost : $910

For more details, and to DIY visit For more details, and to DIY visit www.instructables.comwww.instructables.com Search - Solar Powered TrikeSearch - Solar Powered Trike

Purchase at Purchase at www.solartrike.comwww.solartrike.com - same concept, more - same concept, more refined / expensiverefined / expensive

Resources / Cost BreakdownResources / Cost Breakdown

The Trike cost $910 to build The Trike cost $910 to build

Schwinn Meridian Trike $250.00 www.K-Mart.comSchwinn Meridian Trike $250.00 www.K-Mart.comQcell Solar panels $330.00 www.Ebay.com....Qcell Solar panels $330.00 www.Ebay.com....Charge Controller $ 95.00 www.solarsellers.comCharge Controller $ 95.00 www.solarsellers.comElectric Hub Motor Kit $260.00 www.goldenmotor.comElectric Hub Motor Kit $260.00 www.goldenmotor.comBatteries $ 60.00 Earl's industrial Batteries $ 60.00 Earl's industrial

liquidation, Hawthorne liquidation, Hawthorne High pressure tubes $ 15.00 Any bicycle storeHigh pressure tubes $ 15.00 Any bicycle store

Total Total $910.00$910.00