Wednesday, 15 July 2009

Power from the air

People often ask me about how gadgets will be powered in the future. In the short term, we will see better chemistry allowing batteries to improve, alternatives to batteries such as fuel cells for some applications, and components within devices which consume less power or manage their power consumption more effectively. In the longer term, power harvesting from natural sources, from movement and kinetic energy will be employed too, and we should make progress on bio-organic solutions that work in a similar way to how nature powers itself. Some recent research by Nokia is one of the harvesting solutions.

The Nokia research describes how they can harvest energy from ambient radio waves. This is similar to how some RFID tags are powered, such as those used in anti-theft applications. Currently experiments have been successful in harvesting 3 to 5 milliwatts of power which can charge a device which is in standby mode. The goal of the research is to harvest up to 50mW, and recharge a device which is turned off. Typically, energy harvesting from ambient radio waves has been done with traditional radio receivers and transmitters which have a limited range of usable radio waves. The Nokia example of extracting power from the air uses a very wideband receiver which works between 500MHz and 10GHz.

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