Solar Powered Electric Bike Project Aaron Shipman Advisor: Dr. Xingwu Wang Project Goals: To successfully power a commercially available electric bike with solar panels. The bike is to be stored in a shed with the panel(s) mounted on top. Electric bikes and scooter are available for purchase today. These vehicles are normally powered by a rechargeable battery pack that is plugged into a wall outlet after the batteries drain. This projects goal is to replace the stock battery charger with one that is powered by solar panels. This would require minimal cost to sustain operation (i.e. no charge for electricity, no cost for gasoline). Tentative Bill of Materials Tiger Electric Scooter •Battery Type: Dual 12 volt, 10 amp/hour, rechargeable battery pack •Motor Type: 24 volt, 400 watt continuous / 800 watt peak power •Recharge Time: 3-7 hrs (with wall outlet charger) •Top Speed: 15 MPH AP-30 Photovoltaic Module •More than 1.8 amps charging current in full sunlight •Weather / hail resistant •Open Circuit Voltage: 21.5 volts •Max Power Voltage: 16.7 volts Timeline Project Start Date: 4/17/03 Parts: 3-5 weeks (circuit design, selecting parts, delivery time) Assembly: 3-5 weeks Testing: 2-4 weeks Estimated Project Completion Date: 6/21/03 Project Status Ongoing Activities: •Correspondence with electric bike dealers and solar panel dealers. •Budget acquisition and preparation for purchases. •Researching in the area of charging circuits. •Parts yet to be ordered, circuit yet to be built. Although the research described here is partially funded by the United States Environmental Protection Agency, it has not been subjected to the Agency’s required peer and policy review and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred. Charger Details The scooter has dual 12 volt, 10 AH batteries connected in series, charged by a 14 volt, 1.2 – 1.5 amp wall outlet charger. The solar panels provide more than 14 volts, and more than 1.2 A, so the circuit in between the scooter and panels should limit the current and voltage should they get too large. Also, the new charging circuit should prevent the overloading of the batteries. If the output from the solar panel dips (cloudy day), the batteries will just take longer to charge. This simplifies circuit design. Different charging circuits are being researched and one that meets the requirements will be selected / created. Below: AP-30 Solar Panel dimensions Left: Tiger Electric Scooter with detachable seat / basket Project Benefits There are many benefits to using solar power. Solar power is free, it just needs to be harnessed. After the initial investment, the solar scooter will pay for its self. Operation of the scooter will be simple. After being taken out for a ride, the user will simply have to put the scooter back in its shed and plug a wire in. No going to the gas station required. The scooter will charge its self and cease charging when the batteries are at full load. A scooter like this is ideal in an area where destinations are relatively close together, like a small town or dense city. In a city, electric scooters would cut down on pollution, traffic in the streets, and use of gasoline. This type of alternative energy has the capability to greatly reduce emissions and dependence on foreign oil. This work is partially supported by EPA/CEER.