Limitless on-board power for cars and airplanes in the future?

A team of researchers from the City College of New York (CCNY) is developing a method of harvesting energy from the movement of cars and airplanes, technology that could have a dramatic effect on fuel consumption in the future.

According to the scientists, small, almost flat devices could be mounted on the exterior of cars or airplanes, generating enough current from the airflow to power  on-board systems such as batteries, mobile phones or personal electronics for all the tourists on a bus.

"The voltage we got out in laboratory testing in our wind tunnel is between 20 and 30 volts which is huge in comparison to the size of the device - 30mm x 16mm x 0.2 mm," explains CCNY Professor Yiannis Andreopoulos. "These devices open the possibility to continuously scavenge otherwise wasted energy from the environment."

The project is based on the principle of piezoelectricity, the ability of some materials to generate an electric field in response to mechanical stress and therefore produce electricity from the kinetic energy of motion.

The team is currently working to optimize and increase the power output using wind tunnels and other modeling data to determine the most efficient positioning. Professor Andreopoulos hopes that if the current stage of research is successful, a device could be available commercially in under two years.

This principle of "energy harvesting" is an area of significant interest for both military and civilian purposes, primarily because the input energy already exists and therefore may be considered "free." The power produced is normally too low to power anything but tiny devices - until recently wristwatches were the most widely available example of kinetic-to-electric energy harvesting. However, as power consumption declines and products become more efficient, the application of such technology is becoming more practical.