AN enterprising student has invented an environmentally friendly form of "soler" power to recharge her mobile phone.
Tracy Robertson, 34, from Aberdeen, who is studying for a BSc Honours in design for industry, has created a shoe insole that contains a battery charger powered by walking or jogging.
The average person produces 100W of electricity a day and Ms Robertson decided to harness this power.
The E-sole, is on display at Gray's School of Art degree show. Ms Robertson said: "It is very small and I believe it could be built in by a trainer manufacturer."
AN enterprising student has invented an environmentally friendly form of "soler" power to recharge her mobile phone.
Tracy Robertson, 34, from Aberdeen, who is studying for a BSc Honours in design for industry, has created a shoe insole that contains a battery charger powered by walking or jogging.
The average person produces 100W of electricity a day and Ms Robertson decided to harness this power.
The E-sole, is on display at Gray's School of Art degree show. Ms Robertson said: "It is very small and I believe it could be built in by a trainer manufacturer."
Via (The Herald)
It makes no sense to say someone produces "100W" per day. To start with, Watts are a measure of power, i.e. work done (energy) per second. The correct units should be Joules (J). If someone generated 100W continuously, this would amount to 100*60*60*24 = 8.64 MJ. Convert this to Calories by dividing by 4.2 = 2 million Calories! Since the average person eats about 2,500 Calories in a day, this is clearly impossible. In addition, the amount of energy converted by the insole will clearly depend on how it works. Piezoelectric methods are extremely inefficient - converting about 1% of the mechanical energy put in. Mechanical methods (using some sort of alternator) are better, but take up too much space. I would like to see how Ms. Robertson tackled the problem. I confess I am sceptical that it is possible. There have been many such reports in the last few years (e.g. Trevor Bayliss of clockwork radio fame who claimed to charge a mobile walking in the Namibian desert), but we never hear anything more after the initial media stories. I fear we are being misled by self-publicity and bad science.
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