On Sat, 10 Jan 2004 16:01:09 -0000, "Set Square"
wrote:

The generators in question both essentially generate DC and use inverter
technology to produce AC. [I presume this is easier than generating AC since
it doesn't require accurate speed control].

I think the issue is more to do with matching power to load, a
synchronous genset will be running at either 1500rpm or 3000rpm
depending on the poles of the alternator, it is only optimally matched
to the load at 75%ish of its max power. The inverter set can vary
speed to match the load better. If this gains more in thermodynamic
efficiency than the ~10% electrical losses of rectifier and inverter
then fuel cost will be lower, also the engine life will be extended.
From my experience of selecting a genset to match peak loads I found
the average load was 1/5 of peak.

I suppose you could build much the same with an ex military battery
charging genset, 24volt battery and a couple of inverters (1 near sine
wave for sensitive equipment , 1 cheaper modified square wave for less
fussy stuff) in parallel. The battery could be automotive as it would
only handle peak loads or until the genset came up to speed. Float
charge the battery and have the genset start using the same inputs
either Dave P or yourself suggested. The Honda i series is neat
though.

AJH