USA - Researchers use wind power to power wireless networks

Priya, an assistant professor of materials science and engineering at the University of Texas at Arlington, has designed a miniature windmill that -- with a light breeze -- could provide enough energy to power a wireless Internet sensor. With such a powerful and lightweight power source, the use of Wi-Fi sensors could be expanded to almost anywhere, dramatically increasing the ability to gather data, Priya said. The energy source behind Priya's windmills comes from the growing field of piezoelectricity, which uses certain crystals that generate an electric current when pressure is applied to them. The technology is similar to electromagnetic induction, used in battery-free flashlights that only need to be briefly shaken to generate enough juice to work.

For example, geologists measuring seismic activity in Pakistan to try to gain advance warning of an earthquake typically have to use battery-powered sensors to transmit data or connect the sensors to electric cables. At that rate, a windmill could store enough power for a remote sensor to transmit a signal about every two hours, Priya said. Next month, Priya is holding a conference on piezoelectric energy harvesting at UT-Arlington's Automation & Robotics Research Institute in Fort Worth. The field of piezoelectricity has been steadily advancing since the mid-1950s, and in recent years has gained favor for use in cell-phones as a way to sort radio frequencies, according to Dr. Daniel Stutts, associate professor of mechanical engineering at the University of Missouri-Rolla, who has studied piezoelectricity since 1993. The sensors could be programmed to send out a signal when moved, creating a wind-powered home security system. Replacing solar panels, which can be bulky and unreliable as a power source, is an area where Priya thinks his windmills could someday have their biggest effect.