In Our Backyard
The power has just gone off. It’s dark as a dungeon, and you frantically fumble for the flashlight. Finally, flashlight in hand, you thumb the switch and — right. Dead batteries.
Sound familiar? Now imagine grabbing that flashlight, shaking it for about 30 seconds, and voila, you have 5-20 minutes of bright light. This new flashlight never needs batteries because when you shake it an internal magnet passes back and forth through a coil producing electrical energy. A capacitor stores the energy while an energy sipping light emitting diode (LED) supplies the light.
A batteryless flashlight is just one of the fun ways we can take advantage of renewable energy — energy that does not use up resources like oil, natural gas or coal — until you reach the state of total energy-independence with your “off the grid” house, complete with solar panels and windmills.
While we are talking about human-powered devices, how about a radio that you wind up and it plays for 30 minutes? Inside is a spring that slowly winds down, turning a small electrical generator. Some radios come with shortwave reception, built-in flashlight and solar panels.
More up close and personal is the self-winding watch that uses the swinging of your arm to keep ticking. What is really environmentally friendly about these watches is that they don’t require the mercury-containing button batteries used by digital watches.
And what about all your existing electronic devices such as cell phones, PDAs and GPS units that use rechargeable batteries? There are solar chargers for these as well. Charging times are between two to eight hours depending on the amount of sunlight.
Finally, even if you‘re heating your home without the need of electricity or oil, maybe you still need a fan to move the heat around. The Ecofan, which works on the Peltier effect, sits on your woodstove where the heat difference between the hot stove surface and cooling fins on the top of the fan produces electrical energy that runs the small fan motor.
Will all these devices save you a bunch on your electrical bill? Probably not. But, it is a fun start toward the concept of environmental energy independence.
Happy holidays!
This column was submitted by David McCaskill, an environmental engineer with the Maine DEP’s Bureau of Remediation and Waste Management. In Our Back Yard is a weekly column of the Maine Department of Environmental Protection. E-mail your environmental questions to infoDEP@maine.gov or send them to In Our Back Yard, Maine DEP, 17 State House Station, Augusta, ME 04333
