RCA revealed in the Consumer Electronics Show 2010 that a small charger that can harvest WiFi signals and convert it into electricity, reported PhysOrg.com.

The Airenergy unit converts the WiFi antenna signal to direct current power to recharge its own internal lithium battery whenever it is near a WiFi hotspot.

Phones or other devices can be charged by plugging the charger into the phone¡¯s Universal Serial Bus port to transfer its charge.

The Airenergy was able charge a BlackBerry phone from 30 percent charge to fully charged in around 90 minutes using nothing but the available WiFi signals in the electronics show¡¯s venue.

However, the device¡¯s recharging time depends on its proximity to the WiFi signal and the number of WiFi sources in the vicinity.

The Airenergy charger is planned to be sold at around $40 later this year. A WiFi harvesting battery will also be available before the year ends.