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[Gabey8]

http://www.techtickerblog.com/2008/02/29/body-heat-to-power-your-cellphones/

Body heat to power your cellphones

29th February 2008


Could you imagine a situation where your cellphone would never run out of battery? Even more, the cellphone would be charged by the heat generated by your body. German researchers have concluded that the difference between the body temperature and the normal temperature can help produce electricity. The concept which is based on Thermoelectric Generation can currently generate power of up to 200 millivolts but it needs to be increased to about 5 to 10 times to power a normal electric device.

Research is still on and smaller devices are already being powered by the human heat but one of the major task in their hands is power tomorrow’s cellphones, so that one doesn’t need to charge them every now and then. Another scientifically proven fact to support that being Hot is Good!

Imagine if we could charge an external battery that could be used to run an XO, using the principles that are being researched in the above article? We could charge those batteries via body heat or maybe via other sources of heat (like the excess heat that some appliances, including computers, throw off). We'll NEVER run out of that resource -- here's hoping that they refine these ideas into usable products.

[sloe]

This seems like nothing more than a Peltier Cooler wired backwards. A Peltier Cooler uses DC voltage to create a temperature differential between two pieces of metal.  A few years ago, Peltiers were all the rage for overclocking the venerable Celeron 300A and it's descendants because it was, in effect, a refrigeration unit attached directly to the CPU.

When I started writing this, I went to dig up some info and refresh my memory.  What I found could be pertinent to our discussion:

Wikipedia: Thermoelectric Effect

In the mission area of the XO, this could be an effective power generation method, using running water (like from a stream or river) to chill the "cool" side, and leave the "Warm" side in the sun.  I suppose you could even bury half of it in the ground, a-la geo-thermal heat pumps - you just need an effective temperature differential.

In every day life for us "privileged" XO owners, there are countless situations where a drastic temperature differential exists - like you mentioned, the waste heat from computers.  But take it a bit further - what about the light bulbs in your home?  Only about 40% of the electricity used in a normal light bulb is converted to light - the rest is heat.  Maybe we should invent a light fixture that absorbs the waste heat and turns it back into DC voltage (hmmm...patent idea  )

The biggest problem with this technology, however, is it's efficiency, or lack thereof.  Hopefully, these Germans have cracked the 5-10% efficiency mark, which would be the only way to make this technology truly useful.

[mattd]

Using peizioelectric nanotube cloth to produce electricity through body movement.

As with all this other stuff, it's in the baby phase of research.