Human power is an often overlooked form of renewable energy with quite a bit of potential. As energy prices rise with no relief in sight, more companies are developing devices designed to harness human power and make use of our most natural resource: our own bodies. There are a number of ways to generate human power, and in fact most of them are based on principles we use every day that many people don't realize actually produce energy.
Perhaps the most common example of human power in modern devices is the Faraday flashlight. Retail department stores and television sales offer these "eternal" flashlights that need no batteries. Rather, they are run by human power-simply shake the flashlight vigorously for about thirty seconds, and the flashlight will produce a strong, steady source of light for several minutes. Faraday flashlights operate using magnets and copper coils.
Human power can also be used for crank generators, which are devices that generate electricity by manually turning a crank. Crank generators often incorporate built-in flashlights, and are available with a range of energy output. Small human power crank generators can produce enough energy from three minutes of cranking to power a dead cell phone for two to eight minutes. Larger capacity crank generators are capable of much more energy output.
The most popular and effective method of human power generation, however, is cycling. There are several devices that can convert human power from cycling to energy. Most are either free-standing equipment with pedals attached to a generator, or a portable device that actually attaches to a bicycle and generates power while you ride. Human power is an exciting form of alternative, renewable energy that offers the added benefit of exercise while you pump out power.