Wednesday, October 23, 2013

USB to solve the energy crisis

Or so thinks The Economist.  I don't think so myself.  Universal Serial Bus was added to computers  not so long ago, claiming to replace the multitude of special connectors (keyboard, mouse, printer port, RS232 serial port, mike and speaker plug) with one size to fit all USB connector.  It's done fairly well on the computer front, all computers have some now.   As a side effect, USB will furnish very modest amounts of low voltage DC power so the low draw things like mice can omit the customary "wall wart" power supply.
   Cell phone makers have started offering USB cables to allow recharging of cell phones off computers.  Which makes a certain amount of sense, computers are everywhere, and with USB you can recharge on the road and only have to carry a cord, rather than a heavy little wall wart. 
   Groovy and all.  The Economist hails this development as a major break thru in energy conservation, claiming that the hi tech power supply of the PC saves juice compared to the "always on" wall wart left plugged in all day.  
  Not really.  At least not in the real world.  We are talking about nit noy amounts of power here.  USB only supplies 10 watts.  Compared to the current draw of air conditioners, stoves, water heaters, clothes driers, oil burners, and TV sets, 10 watts is nothing.  Ten watts left on for an entire month is only 7 kilowatts hours.  My clothes drier uses  that much juice to dry just ONE load of wash.
   Methinks The Economist needs to consult a real electrician.  

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