Renewable Energy: Pedal Power!

Transcription

1 2.workshops 6.renewable energy 8.pedal power-supporting materials pg 1 Renewable Energy: Pedal Power! Supporting Materials Pedal Power Around the World Building a Bicycle-Powered Generator Helpful Resources

2 2.workshops 6.renewable energy 8.pedal power-supporting materials pg 2 Pedal Power Around the World San Francisco, California Shake Your Peace ( o Gabe Dominguez and his band have toured on bike through Utah and California, playing shows in remote locations using the pedal-powered sound system that Gabe built himself. Rock the Bike ( o This Berkeley-based venture builds and sells custom pedal-powered sound systems, bicycle-blenders, and lots of other cool stuff. San Francisco Bicycle Music Festival ( o Started as a collaboration between Gabe Dominguez of Shake Your Peace and Paul Freedman of Rock the Bike, this day long festival is now in it s fourth year. Bicycle generators produce all electricity used to run the sound for the festival and all gear is transported by bike! Kigali, Rwanda Nuru Lights (nurulight.com) o This Rwandan-based social enterprise works in several countries in West Africa to provide clean and affordable systems that can be charged using a pedal-powered generator Eindhoven, The Netherlands Gionata Gatto ( o This Italian designer has taken the pedal-powered generator to a whole new demographic by producing a sleek wooden floor lamp unit called the Pedalator. San Andrea Itzapa, Guatemala Maya Pedal ( o This NGO designs and builds various pedal-powered machines, including water pumps, grinders, threshers and blenders. Toronto, Canada Chocosol ( o This learning community/social enterprise makes artisanal chocolates in Toronto. All of their products are delivered by bike and they also make use of a pedalpowered cacao grinder. Chocosol is currently developing an off-the-grid kitchen that will be powered in part by bicycle generators.

3 2.workshops 6.renewable energy 8.pedal power-supporting materials pg 3 Building a Bicycle-Powered Generator Tools and Materials Required Materials o bicycle o bicycle trainer stand (Image 1) o a piece of plywood, approximately 24 by 24 o machine screws and/or L-brackets o 12 volt DC motor (Image 2) o multimeter (Image 3) o replacement chuck for an electric drill and chuck key (Image 4) o one 50 volt 6 amp diode (Image 5) o 12-gauge copper wire (red and black) o push-on connectors (Image 6) o red and black electrical tape o plumber s tape o 8 screws, 1/2 long Tools o wire strippers o screw drivers Optional Materials o 12 volt sealed lead acid battery o battery charge controller o 400 watt DC to AC inverter o car stereo amplifier o speakers o portable compact disc or mp3 player Image 1 Image 2 Image 3 Image 4 Image 5 Image 6

4 2.workshops 6.renewable energy 8.pedal power-supporting materials pg 4 The Idea in a Nutshell Usually, you run electricity into an electric motor and the shaft of the motor turns to carry out some sort of task. If instead, you reverse this process and turn the shaft of the motor, electricity will be produced. By making use of the mechanical advantage inherent in a bicycle, you can transfer the effort of your pedalling to spin the shaft of the motor, which converts this kinetic energy into electricity. The electricity can be used directly or stored in a battery. Assembly Instructions Step 1: Preparing the motor Using the chuck key, attach the drill chuck to the shaft of the motor and tighten securely. The chuck will act as the interface between the bicycle tire and the motor and will allow you to spin the shaft of the motor by pedalling your bike. The motor should be orientated so that as the bicycle tire rolls against the chuck, the chuck tightens (otherwise, the chuck will eventually loosen and fall off.) At this point you can also determine the polarity of the motor by connecting your multimeter (set to measure volts in DC) and turning the shaft in the direction that the tire will eventually spin it. If the multimeter gives you a negative reading, switch your probes and try again. Mark the positive wire with red electrical tape and the negative wire with black tape. Step 2: Setting up the bicycle and trainer stand Remove the resistance mechanism from the trainer stand and place the stand on top of the plywood, which should be lying flat on the floor. Mount your bicycle on the stand and make sure that it is securely in place. The stand should be placed in the centre of the plywood with enough space for small adjustments in position. Place the motor so that the chuck fits snugly up against rear tire of your bicycle and mark this position.

5 2.workshops 6.renewable energy 8.pedal power-supporting materials pg 5 Step 3: Mounting the motor Depending on the motor that you are using, this stage may take some innovation and creativity. Many motors have threaded holes that will accept machine screws. If your motor has these on the bottom, simply drill holes for the appropriate size of machine screw and attach the motor so that it rests directly on the plywood. You may need to countersink the holes so that the screw heads do not protrude from the bottom of the plywood and cause it to rock. If the threaded holes are on the ends of the motor, you can attach two L-brackets to each end of the motor (it is a good idea to use lockwashers) and then use screws to fasten the motor assembly to the plywood. Once the motor is securely attached to the plywood, ensure that the tire is touching the chuck and then try pedalling the bike. You may need to make slight adjustments if the tire slips or if it is extremely difficult to pedal. When you have established a working position, you can secure the trainer stand to the plywood using plumber s tape and screws.

6 2.workshops 6.renewable energy 8.pedal power-supporting materials pg 6 Step 4: Building the circuit Warning: To avoid injury, this step should only be done under the supervision of a licensed electrician. Connect your multimeter to the motor s wires and double-check that you have marked the polarity correctly by turning the wheel of the bike. If the red probe is connected to the wire marked with red tape and the black probe is connected to the other wire, you should get a positive reading. At this stage, you can test the output of your generator by getting on the bike and pedalling. You should be able to reach 12 to 14 volts of DC voltage without too much effort. Next you can build a circuit that will allow you charge a battery. It is important to include a diode in this circuit so that when you hook up your battery it will not send power to the motor and turn the shaft (after all, that s what the motor was designed to do). A diode acts as a one-way gate that allows electricity to pass through in one direction but not the other. Orient the diode so that the end marked with a solid line is pointing away from the red wire on the motor and attach the end of the diode without the line to the red wire. (This can be done with electrical tape, push-on connectors, or by soldering the connection.) Next, connect the other end of the diode (the end with the solid line) to a length of red 12-gauge wire. The other end of this wire will eventually hook up to the battery. Now attach the black 12-gauge wire to the negative lead from the motor (which you marked earlier with black tape) using a push-on connector. Test your circuit by attaching the multimeter probes to the red and black wires respectively and pedalling. If you get a positive reading, you have wired the circuit correctly. You can now attach the red wire to the positive terminal of the battery and the black wire to the negative terminal. To charge the battery, make sure the multimeter is connected to the circuit and pedal until it reads 12 volts. IT IS IMPORTANT NOT TO PEDAL FASTER THAN 14 VOLTS, OR YOU RISK DAMAGING THE BATTERY AND INJURING YOURSELF. As an extra precaution, it is advisable to include a charge controller in your circuit, which will cut out when the current when the generator reaches 14 volts or when the battery is fully charged. Follow the instructions provided with your charge controller when including it in the circuit.

7 2.workshops 6.renewable energy 8.pedal power-supporting materials pg 7 Step 5: Using the Electricity Now that you are producing electricity and storing it in a battery, you need to figure out how to use it. By connecting a portable DC to AC inverter to the battery, you can plug in most household devices and use the electricity that way. A more efficient use of the energy that you have created is to hook up an electrical device that runs off of DC power directly to your battery. For example, a car stereo amplifier is designed to run off the power from a 12-volt car battery. Connecting the amp directly to your battery will allow you to play music from a portable compact disc or mp3 player through a set of speakers. Helpful Resources The Human-Powered Home: Choosing Muscles over Motors by Tamara Dean ( provides detailed instructions for building a pedalpowered generator and many other human-powered devices. There is also a wealth of valuable resources on the Internet to guide you on your way, including many instructional videos. Below are two comprehensive sites: