California Fitness, a Hong Kong based subsidiary of 24 Hour Fitness Worldwide, was the first gym to explore ways of harnessing and reusing the power of its clients. In 2007, the gym introduced the “Powered by You’ program, using energy burned off by exercisers to power lighting fixtures and store surplus energy in batteries for future use.
According to Steve Clinefelter, President of California Fitness, “One person has the ability of producing 50 watts of electricity per hour when exercising at a moderate pace. If a person spends one hour per day running on the machine, he/she could generate 18.2 kilowatts of electricity and prevent 4,380 liters of CO2 released per year.”
Today, at the Green Microgym in Seattle, members can generate enough electricity to power the gym’s music system or run their own personal DVD player. The energy bar one member just ate powers the ceiling fan for the next three hours. Another member’s morning coffee is doing its part to keep the lights on. Every revolution on the elliptical is churning pure electricity back to the grid.
The elliptical machines and recumbent and upright bikes capture energy produced from the flywheel. Cords send the converted AC current into any standard wall outlet, and the energy created is automatically used before the building draws power from the grid. A limitation of these machines is their inability to store surplus energy.
The Human Dynamo, an exercise machine consisting of four spin bikes attached to a small generator, can produce 200 watts to 600 watts of energy an hour, depending on whether all four bikes are in use.
An average workout creates 37.5 watt hours, according to owner Adam Boesel. The gym does not yet generate enough electricity to be carbon-neutral, but if all the equipment gets used at one time, it can produce twice as much as it needs to run the facility at any given moment.
These developments in human-generated electricity are laying the groundwork for future gyms which will be entirely client-powered. This promotes personal fitness, business savings, and a net benefit for the environment.