X-Message-Number: 10502
Date: Thu, 01 Oct 1998 11:12:26 +0100
From:  (John de Rivaz)
Subject: Re: backup generators

In article: <> Charles Platt writes:
> For the consumer, gasoline generators are not an easy answer. They are
> expensive (typically $1,000 or more for a few KW) and, guess what, they
> consume gasoline. According to my calculations, if I wanted to sustain my
> freezer and various other "necessities" here, for up to a month, I would
> have to install a tank to hold at least 500 gallons of gasoline in my 
> back yard. My neighbors might not be amused.

Neither would the "planningpolizei".

However in the UK (and I imagine it is the same in the US) you can store up 
to 600 gallons of diesel oil (normally done for central heating). I would 
guess that in the US you could buy a diesel generator of 5kW capacity for 
$500, especially if you went into for second hand reconditioned one. Diesel 
engines are inherently very reliable, as they have fewer working parts than 
a gasoline engine. 

If you plan to run it continuously for a month, then I recommend a lower 
speed one, 1,800 rev/min, rather than 3,600 rev/min, although the latter 
could be cheaper, smaller and lighter. Wear is proportion to the cube of the 
speed. A water cooled unit is more expensive, but quieter and you can use 
the waste heat more easily (connect the water flow to a radiator inside 
living space.) Cooling the exhaust silencer with a couple of computer fans 
wastes little power yet prolongs its life.

Vibration and noise can be reduced by standing the unit on two or more old 
car tyres (without wheels or inner tubes) lying on their side.

Some people deliberately generate power this way and use the water to heat 
their large home or small business. The electricity is essentially a "waste 
product" from the heating process that can cut down their utility bill. It 
is called "combined heat and power" but unfortunately the output of 
commercial units is usually excessive for the average home.

-- 
Sincerely,     * Longevity Report:  http://www.longevb.demon.co.uk/lr.htm
John de Rivaz  * Fractal Report:    http://www.longevb.demon.co.uk/fr.htm
**************** Homepage:http://ourworld.compuserve.com/homepages/JohndeR
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