DC Pumps [RE-wrenches]

[hugh piggott]

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At 11:04 pm +1200 30/6/01, Carl Emerson wrote:
>hugh piggott wrote:
>
>"Isn't there a new-fangled gismo you can buy nowadays called an 'inverter'?
>Or am I missing something..."
>
>I believe that a brushless DC motor delivering equal torque is may times more
>efficient than an AC motor.
>We always look for a DC solution for pumps etc. A second advantage when using
>a Trace SW set-up is the ability to operate off the battery bank during sleep
>mode, without waking up the inverter.

Sorry I did not reply to this earlier, Carl.  I understand that DC 
pumps are ore efficient than AC ones, and I am learning just how big 
the difference is, although I am not sure I understand essentially 
why this should be so.

I also understand the advantages of 'sleep mode' in terms of saving a 
hundred (or so) watt-hours of energy per day.  This falls into the 
category of 'phantom loads'.  I am ambivalent on that one, myself.  I 
personally only carry out a vendetta on my phantom loads when wind is 
scarce.  Much of the time I tolerate them as being just a (very 
regrettable) part of using modern appliances.

The way I see it, small renewable energy systems ought to be 
available to the public as 'plug and play'.  It should not be 
necessary to modify your appliances or lifestyle to a serious extent, 
except when it really matters (like in exceptional weather if you 
wish to avoid/minimise engine run time).

I cannot see that many people will want to use special DC circuits, 
and/or do without 24-hour power unless there is a considerable 
pay-off.  Perhaps in the case of pumps the pay-off is there.
-- 
Hugh

http://www.ScoraigWind.co.uk

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