Micro CoGen.

That's interesting about the belts higher efficiency.  It's sort of counter intuitive, but I think your right about that being the best way to go.  Belts and pulleys will be easier to put together too, as the gearing is greatly simplified.

By my calculations,  210 amps is about 6200 watts which is around 8.3 horsepower.   I should have mentioned that I kind of like to run every thing at well withing their limits to get max life, for both the engine and the alternator.

Add to this, I have read you get a significant loss's due to running petrol engines on methane or wood gas,  so I thought I would max out the HP by around 3 fold.  I would like to hear if any one has any real world experience with this, as so far my plans are compiled from web info and lots of spread sheet calculations.

I would love to have to only fit one alternator.  I was hoping to over rate the alternator by 100 % as well.  That would mean I would need a 400 amp 12 Volt unit,  as per Mobile_bob's white paper.  I thought I would follow his advise, and go with 2 *  Prestolite Leece Neville 110 555jho alternators, but if there is a 300 plus amp 12 volt unit out there that I can afford without selling my home,  I should go for that.

I was hoping to find a 2nd hand 4 stroke outboard, and try it just to see if it works, but if I can find a 20 hp water cooled diesel, that would be nice too.     As yet I am still looking for an engine to make the job as easy as possible.

Thanks for your ideas, as its all very helpful.

or should I say " Professor Bob " lol

Hi,   I am in need of a 210 amp 24 volt charger.  Does any one know of a simple way to couple 2 alternators ( at 105 amps each ) to a single shaft of an engine ?    I am hoping to skip the use of pulleys.

I was thinking of giving the idea of a out board motor a go...   I have heard that the reduction gear box ( 2 to 1 ) is right down the bottom near the propeller.  May be the cogs can be reversed,   but I would still have to raise it up to 1 to 3....

I  thought I would go for a 20 to 25 HP unit, so I could run it at a slow rpm,  and use Bobs ideas of an external regulator.  ( Thanks Bob )

One idea could be a small Diff....   but I don't know what the gearing is like, from the drive shaft to the wheels....

any ideas ?

Mike