If you want to go electric..take fossil fuel HP
in boat and divide by 4 for electric equivalent. If
you want regenerative feedback from prop the most
will come from a brushless DC magnet motor and you
should consider changing the prop to the biggest 3 blade
you can fit into the aperture of the boat. In
brushless DC motors, and assuming an efficient prop, you
will need approximately 50 foot pounds of torque which
will relate to full speed in worst conditions
(1amp=1ft.pound over 120-144 VDC and 50 amp hours at max). This
will be much less in becalmed conditions. My 10 ton
Casey does 5 1/4 knotts on 25 amps in calm and 35 amps
working against a 22 knott head wind. Regenerative
feedback on brushless DC will allow you to have a 3 or 4
to 1 recharge ratio (for every hour on motoring you
must sail for 3 or 4 to put energy back) in light
sailing wind of 10 knotts. This can be as little as 2 to
1 in heavy air. <br> For continuous off shore use I
recomend a FischerPanda AGT DC generator in combination
with a smaller battery pack. For your application 150
amp hours (2 1/2 hours motoring on batteries) and a
6kw AGT will give you unlimited motoring with 3 to 4
times the fuel economy of the standard diesel. This
does not include additoional saivings from
regenerative sailing which, given the right wind conditions,
will carry you 80% of the time.<br> Look for a motor
that is sealed, inverter duty, continuous duty,with
thrust bearings and marinized. ewhel@....
(301)274-4479
