[LINK] Some shocking news about wireless electricity

Stewart Fist stewart_fist at optusnet.com.au
Mon Jun 11 11:47:19 AEST 2007


Adam writes about Witricity:

> Of course no details on how much energy is used in the power emitting
> device.  To drive a 60 watt light bulb I'd guess it's pretty damn
> high!  I know I need 5 watts to drive a 300 mW circuit.  But then I
> don't have lab and bottomless pit of money to throw at R&D :)


Whatever the technology, it still has to obey two fundamental laws of
physics

1. you can't get out more energy than you put in
2. Inverse square law

Then there's the inherent inefficiencies in electronics, and in transforming
one form of energy to another.

In combination, this will always mean that such devices are enormously
inefficient -- at a time when everyone has begun worrying about the power
being consumed by their digital alarm clocks and TV standby.

I thought this announcement was about the most ridiculous I'd heard since
the announcement that they were going to use the power lines to distribute
HDTV.

I can imagine that there are some minor uses, but as a consumer product to
charge cell-phones, it is in cloud-cookoo land.

-- 
Stewart Fist, writer, journalist, film-maker
70 Middle Harbour Road, LINDFIELD, 2070, NSW, Australia
Ph +61 (2) 9416 7458




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