A Cell Phone that charges without being charged!?

Free Energy?  Cold Fusion?  The Force?  Kind of, sorta, perhaps...

Researchers at cell phone manufacturer Nokia's labs have admitted that Nokia is developing technology that can harvest ambient electromagnetic radiation to keep a cellphone going.  The research is working towards the goal of harvesting 50 milliwatts of radio frequency energy from the radio spectrum in much the same manner as an old fashioned crystal radio does but instead of converting the energy into sound waves the energy will be stored on a battery and used to power a cell phone.

Current proto-types can harvest 3-5 milliwatts, the smallest charger that I can find in my home charges my blue-tooth ear bud with 180 milliwatts in about one hour or so to a lithium ion battery.  To charge a 1000 mAmp hour cell phone battery would take days at 3-5 milliwatts but 50mW would be very useful.  The intention is to charge the phone while not in use, this would be an excellent way for cell phone users to never have to worry if they were away from their home or car charger for an extended period of time.

It will require a wide band receiver capable of capturing signals from between 500 megahertz and 10 gigahertz--a range that encompasses many different radio communication signals. Other researchers have developed devices that can harvest more modest power from select frequencies. A team from Intel previously developed a compact sensor capable of drawing 6 micro-watts from a 1.0-megawatt TV antenna 4.1 kilometers away.  This is a very inefficient use of energy and can be likened to leaving your water tap running all day for one teaspoon of water however if ambient radio frequency energy which is already there can be harvested the numbers make sense.

Whether or not your Blackberry will be powered this way anytime soon considering how much the average Realtor uses their cell phone these days is doubtful, but the uses of this system for powering low voltage devices of all kinds is very exciting.