How to utilize electromagnetic energy from the air?

I am sorry for my lap in posting, but I haven't had login info for my blog, after I had gone to Germany about one and half month ago... Now I am back and the story continues!

Imagine, you wouldn't need any electric wires at home, you wouldn't have to pay for any electricity bills...Everything would be charged from the air!...

Well, this claim is rather bombastic than real, but catching energy from the air (to some extent) is now really possible! Scientists have developed interesting method, how to utilize electromagnetic energy which surrounds us everywhere... from TV broadcasting, radio transmitters, cell phone network and even from satellite communication systems!

Georgia Tech School of Electrical and Computer Engineering professor Manos Tentzeris holds a sensor (left) and an ultra-broadband spiral antenna for wearable energy-scavenging applications.
(source: sciencedaily.com)

The truth is, that for many decades we are surrounded by this energy. However, no one was able to use it so far.

Researchers at GTS have come with wide-band antennas, which can scavenge electromagnetic energy in many different electromagnetic ranges. It varies from frequencies of a FM radio to radars ( that is 100 MHz to 15 GHz)

The experiments showed it can't be used  for big machines in the close future because of generating only hundreds of microwatts of energy. However, scientists promise that they can increase this cipher up to 50 miliwatts.

It means: we have a way to run small self-powered sensors or microprocessors!
We can use them in many fields: for biological, chemical, heat and stress sensing for defense and industry; or radio frequency identification (RFID) tagging for manufacturing and shipping, and monitoring tasks in many fields including communications and power usage.

Then, for instance, it could help charging batteries with solar energy : energy from the sun during the day and at night from these scavenging devices (or at least protecting it from discharging)

It can be mostly uselful at the airports, where radars and other communication devices emit a lots of energy.
Thanks to this new electricity-scavenging technology it could be used, for example, to run wireless sensors for detection of explosives!

Furthermore, sensors placed on food could detect chemicals, which are commonly produced, when the food is heading to the end of its durability and deteriorating in quality and thus let know consumers of it.

The possibilities, where to use these sensors, are really broad and I am looking forward to put it into practical use at home :-)


Sources:
http://www.sciencedaily.com/releases/2011/07/110707131545.htm
http://www.novinky.cz/veda-skoly/239464-vedci-nasli-zpusob-jak-vyuzit-energii-ze-vzduchu.html
superstock.com
 http://thinkengine.blogspot.com/
http://3enscience.wordpress.com/2010/06/28/the-electromagnetic-spectrum-how-do-i-remember-it/
http://i.treehugger.com/images/2007/10/24/microsensor.jpg