|The Power Pot at Campsite|
For example, piezoelectric devices that convert mechanical motion (e.g., vibration) to electricity are being used now to power sensors that monitor the health of structures or machinery. The vibrations of the system the sensor is attached to our embedded in, such as a bridge or an industrial motor, provide the mechanical energy that the piezoelectric transducer converts to electricity. If the sensor detects a problem or pending failure, the user can be alerted over a wireless connection.
Solar cells are another, more obvious example but have the disadvantage of generating power only during daylight hours, of course, and work best on sunny days. On yet another front, some scientists and engineers are developing commercial products that capture the ambient radio frequency energy of broadcast television, radio stations, and cellular phone systems and convert it to direct current for powering ultra-low power electronics.
The engineers at Power Practical are harvesting environmental energy by exploiting yet another energy conversion process called the Seebeck Effect, in which a current flows across the junctions of two joined, dissimilar metals when they experience a temperature differential. We've just learned about Power Practical's Power Pot, which generates electricity for recharging phones, GPS receivers, and so on by converting the thermal energy of heated water. Pack a Power Pot along with you on a camping trip and you can keep your mobile devices working even without access to an electrical outlet.
The Power Pot consists of an aluminum pot with a Seebeck Effect module built into it, and a voltage regulator module that functions as the battery charger. The voltage regulator is connected to the output of the Seebeck module with a high-temperature cable. The voltage regulator's output is a standard USB power connection at 5Volts supplying up to 1Amp; i.e., 5Watts. Fill the pot with water, heat it over a campfire or campstove, plug your mobile device into the charger with a USB cable, and it'll be good to go in awhile.
A technical explanation of the Power Pot's operation is given here.
The Power Pot is yet another innovative product funded through a Kickstarter campaign. It retails for $149. We will be watching to see how it fares in the marketplace in the months to come.