William Wixon said:
was wondering if anyone could direct me to a place that sells small diesel
generators. i'd been looking at generatorsales.com 5.5kw yanmar diesel
generator, but then wondered (after posting here about "generator use
question") if maybe i didn't need 5.5kw and maybe ought to go for something
even smaller, was just looking at generatorsales.com 4kw unit and at .2
gallons per hour wondered if there was something even SMALLER for sale
somewhere, i mean, but specifically in diesel.
At least over the past couple of years (I've stopped looking at them as
I got mine) several boat places offer very small liquid-cooled diesel
units at very high prices (relatively). AFAICT they also seemed to be
fibbing about fuel consumption when I went and looked up the engine
maker's fuel consumption data, not to mention basic thermodynamics. I
thought about trying to pry one of the engines alone from a local
distributor, but finally ended up buying a slightly larger complete
unit, used.
Fibbing: claimed output of 2800 or 3000 watts, claimed consumption of
0.125 gph - ie, 0.044-0.041 gallon per KWH. Great fuel efficiency if
true - a bit too great to believe. I suspect the things are
non-simultaneous - it may put out 2800 watts, it may consume 1/8 gallon
per hour, but I sincerely doubt it does both at the same time. At least
generatorsales normally provides full and partial load consumption rates
on their detail pages, even if they also play the misleading game on the
front page (5kw, .24 GPH - but not at the same time, kids). Neither of
the two "boat" places making these unlikely claims would respond to
e-mails requesting clarification or confirmation, and at least one of
the sites had a link to engine performance data that indicates a higher
consumption per watt out of the engine, much less from an alternator
driven by the engine...
If it was truthful, the fuel efficiency would pay the thing off in
fairly short order if you were burning much fuel at all - but I found
the deviation from a typical small diesel value of 0.1-0.065 gallon per
KWH a bit difficult to believe.
Note that the units you appear to be looking at from generatorsales are
air-cooled, and have high-speed (2-pole) generator ends (the
"slow-turning" 5 kw unit is spinning a belt-driven 2-pole generator).
Water cooling costs a bit more, but means you can more easily extract
and use useful heat from your burned fuel - for heat and hot water when
the sun does not shine and you need heat, hot water, and electricity all
at the same time. 1800 rpm (4-pole) generator ends tend to last a bit
better, but cost more up front.
