Human Power Generation in Fitness Facilities Jodi Loo, Frances Yan, and Professor Alice Agogino, Ph.D Department of Mechanical Engineering, UC Berkeley, CA 94720
What we do.
The Human Power Generation (HPG) team is an undergraduate research project that focuses on harnessing the human power easily found in fitness facilities, namely at the Recreational Sports Facility (RSF) at University of California, Berkeley. We aim to convert the exerted energy during exercise into electrical energy that may be used as an alternative power source. Research shows that continuous use of the 28 elliptical exercise machines at the RSF can harness approximately 10,000 kWh over a year. Although this energy amounts only to 0.78% of the RSF’s total energy needs, it is valuable nonetheless.
Why human power?
As energy usage around the world continues to increase, the need to develop sustainable and environmentally-friendly methods of energy generation and conservation is crucial. University recreation centers around the nation have already begun harnessing human power as a source of alternative energy. One of the most popular pieces of cardio equipment, the elliptical trainer, has proven to be the most viable candidate for accessing human power. Compared to treadmills which use excessive amounts of power and damage the user’s knees, ellipticals are self-sustaining and also provide a low-impact exercise.
How?
A standard elliptical creates training resistance through an eddy current braking system, in which eddy currents are developed by electromagnetic induction over a set of resistor coils located at the back of the machine. Unfortunately, the creation of resistance using this system results in excess energy, which is dissipated as heat. Pioneers across the nation have developed a method which allow mechanical energy to be harnesssed as direct current (DC) power. DC power is subsequently converted to alternating current (AC) power by using an inverter to create the training resistance in the machine instead. This AC power can then be fed back into the electric grid of the fitness facility.
Our goals and accomplishments.
We plan to retrofit all 28 ellipticals and provide an educational kiosk through a bike-powered iPad station at the RSF. We seek to demonstrate the potential of human power as an alternative energy source and encourage sustainable lifestyles. In the past two years, HPG has implemented retrofit designs on a recumbent exercise bike and an elliptical machine that successfully allow the exerted energy from exercise to power external applications, such as a charging station for electronic devices. Human Power Generated by Elliptical vs. Resistance Level (65 RPM,10 Incline)
Elliptical Retrofit to Harness Human Power The retrofit for the elliptical machine entails adding a charge controller module to regulate the charging of rechargeable batteries. This way, we have created a charging station that can store energy in batteries while providing a steady output to power any external devices.
Retrofitted Elliptical Efficiency vs. Resistance Level (65 RPM, 10 Incline)
2008-2009 RSF Energy Usage Breakdown
Acknowledgements
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Educational Kiosk through a Bike-Powered iPad Station
A key goal of this project is to initiate significant social impact on the green energy movement. We plan to install a bike-powered iPad console at the RSF, where users can experience firsthand the “power” they are generating. Specifically, the iPad will be charged wholly on the power generated by users exercising on the bike. We hope that the opportunity to directly see the potential of human power will encourage usage of more energy efficient machines, greener exercise choices, and ultimately, more sustainable lifestyle choices.
Elliptical Team: Namkyu Chang, Eric Mao, Rajith Rohan Pedal Team: Matthew Roeschke, Kyle Zampaglione