Move over solar chargers. Step aside kinetic chargers. If RCA are to be believed, there’s a new way to scavenge power from your environment using an energy source that’s all around us: WiFi. If you are reading this article, the chances are very good that you are in range of at least one wireless network. RCA says its Airnergy Charger scavenges stray WiFi signals and converts them to DC battery power that you can use to charge your cell phone, music player, or other electronic devices.
RCA calls the Airnergy a “WiFi hotspot energy harvester”. The device is about the size of a cell phone, with a Micro USB connector hanging off it. Inside is an antenna to receive 2.4GHz (802.11) WiFi signals, and a converter that turns the WiFi energy into DC power which is then stored in the on-board battery. You can keep the Airnergy in your briefcase or your pocket and whenever it is within range of WiFi, it charges itself. Simply connect it to your device to charge its battery. And, unlike solar chargers, the Airnergy works at night.
At the CES 2010 show, RCA claims to have demonstrated the Airnergy charging a BlackBerry from about one-third to fully-charged in about 90 minutes. Naturally, the strength of the WiFi signal will affect how quickly the Airnergy can charge a device.
So is the Airnergy ready for prime time? We’ll definitely be keeping an eye on this technology, but RCA says they are already working on a new version that will be small enough to fit inside an OEM cell phone battery. With the Airnergy harvesting battery pack, you could recharge your phone or other device simply by leaving it range of a WiFi hotspot.
RCA is aiming to bring the Airnergy Charger to market in the third quarter of 2010, with an expected price of US$40.
Via: OhGizmo.
Ed note: While I attended CES, I did not witness this demonstration personally, nor did any other members of the Gizmag team at the event. Indeed, after discussing this, we find it hard to believe that enough energy can be gleaned from a Wi-Fi signal to provide a practical charging solution for mobile phones. It's certainly easy to be skeptical about the "one-third to fully-charged in about 90 minutes" claim. For now, we'll be putting this one in the "believe it when we see it basket".
It takes 50 times that to power a single LED. This means that if their internal battery is 3 volts, 3000mAh it will take about 5000 hours to charge it to full capacity.
There is quite a concentration of this kind of energy in an average urban space, probably enough to charge a battery over a period of, let say a day. The statement that it \"turns the WiFi energy into DC power \" is likely political. WiFi is operated by individuals and there is no claim for the energy emitted. Cellular and other transmissions might have other legal consequences.
About the only thing comparable is a crystal radio, which has barely enough power from the radio wave signal to hear the signal over a earphone... barely. Definitely in the milli/microwatt range.
We are awash in radiofrequency waves from all over the city, nation and world, and the solar system. Just no practical way to capture it and convert it to useable, practical battery power.
I do agree with you, however, that hotspot providers would likely charge an extra \"convenience fee\" or somesuch if they knew that tons of people were charging their batteries (even though it would not cost the provider a dime extra on their electric bill).