Fundamentally, drawing electrical
power from the engine takes hp. HelloSailor can jump in and give you the formula (hp per KWh) off the top of his head
. I would have to dust off some brain cells. Suffice to say, large electrical
power draws, take large hp from the engine.
Traditional belt driven alternators are limited due to the ability of the belts and pulleys to drive the alternator
without slippage. Dual belts help in high draw situations but at some point a direct drive alternator
, using gears, is the right answer.
This looks like a useful modification that yanmar has come up with. It looks to allow high draw and direct a/c power creation. Excellent versatilty. Of course, the high draw items like air conditinoing etc. would require a large bank of storage
batteries and the associated converters or require that the engine be running.
A large stand alone genset (if boat space allows it) is the current
alternative, that doesn't require any retrofit or re-engineing. Even on a current
either the gearbox
has to move back or the engine forward to accomodate the new unit. This would require a bit of engineering work but one I would consider if I was re-engineing anyway.