On Wed, 02 Jul 2014 17:16:27 -0400, Wayne.B
wrote:

The inefficiencies of converting 12 volts to 110 are more than
compensated by the quietness of not running the generator
continuously. The lifespan of the generator is also greatly
increased and we are not tied to a dock with shorepower like most
motor yachts in our size range. The diesel fuel that the generator
does use for battery charging is a drop in the bucket compared to the
main engines, and when we are underway the engine alternators keep the
inverter batts charged at almost no cost at all. For boats that
already have propane for cooking there may be some advantages to also
using it for refrigeration but I prefer to have no propane on the boat
for safety reasons. I also like the convenience of having a single
fuel boat. Down in the Caribbean people from the US are always
juggling propane adapters to use the European butane fittings that are
commonly available.

What's the price of diesel *down island*? I've heard it isn't
cheap. I've heard some places it might be around ten bucks a
gallon. Propane, on the other hand, is generally much cheaper
than that per BTU equivalent

FYI, you don't get something for nothing. It might seem like the
alternators charging a low battery bank don't cause the main
engines to burn much more diesel but they do.

As for being quiet and not running a dedicated generator that's
a good thing but when using propane to refrigerate there is no
noise at all, ever. No fumes either from a generator or the
main engines charging up a battery bank so an inverter can do
its thing and thus waste about 10% of the energy.

Don't most diesel generators such as a typical 8KW version produce
alternating current? If so, think what you do when generating using
it. It generates 120VAC which is then transformed to 12volt DC via
a battery charger to charge the batteries (10% loss). Then you turn
around and invert it back to 120VAC to run the freezer (another 10%
loss). Sounds very inefficient to me.

Also, if you have a freezer full of frozen meat, for example, it
could be worth a thousand dollars or more at today's prices. Your
generator or main engines could break down and you just lost your
meat. An adequate supply of propane will forestall that eventuality.

--
Sir Gregory