Here’s an interesting potential source of electricity — people power. Think about it. People move around a lot during the day, whether it’s walking, fidgeting, gesticulating, or doing something more active like bicycling. Even small movements, hooked up to devices that use tiny generators to covert motion into electrical current, can generate considerable amounts of electricity. I’m reminded of this every day on my bike commute, as a generator built into the front hub of my Breezer Uptown 8 bicycle (http://www.breezerbikes.com/bike_details.cfm?bikeType=town&frame=d&bike=uptown&new=true) powers surprisingly bright front and rear LED lights. I no longer have to worry about batteries dying before I get home, and the slight extra drag created by the generator is imperceptible.
But a bicycle generator hub could be just the beginning. A recent paper in Science magazine describes a small device that turns walking into electricity. It looks like a lightweight leg brace with a gizmo attached near the knee. Bend and straighten the knee, and the device generates up to 5 watts of electricity. Just one minute of walking produces enough electricity to power a cell phone for 10 minutes. The device is the product of nearly a decade of research at British Columbia’s Simon Fraser University and is being developed by a company called Bionic Power (http://www.bionic-power.com/news/PR001.html). It has obvious applications in the military, where soldiers would be thrilled with a better alternative to the heavy battery packs needed power all their electronic gear. But think also about the possible uses for keeping Blackberrys or GPS units humming.