Re: [Amel] Re: Maramu prop shaft alternator

Lars H. Knudsen <museum@...>

On my Santorin 1993 I normally use the propeller generator when sailing but to my experience – and practical measurements – it will cut ½ to 1 knot of the speed unless there is plenty of wind. So sailing in modest wind I have chosen to just let the propeller turn free as setting the gear in “back” in order to stop the propeller turning will cut 1/3 to ½ knot of speed.

So my conclusion is that the propeller generator generates significant drag but is a fantastic opportunity to generate all the power the boat needs for both running autopilot, fridge, lights and all navigation equipment – and still have excess power to charge the batteries.

Best regards


Santorin Salvagny – presently Gibraltar / Alcaidesa

Fra: amelyachtowners@... [mailto:amelyachtowners@...] På vegne af Richard03801
Sendt: 21. juli 2011 14:16
Til: amelyachtowners@...
Emne: Re: [Amel] Re: Maramu prop shaft alternator

Hi Kent we have sailed 1000's of miles with a wind Gen atop the mizzen mast without issues. At 30 mrs it self feathers on we go.


Richard Piller

Cell 603 767 5330

"brokerage beyond your expectations"

On Jul 21, 2011, at 1:31, "Dave_Benjamin" <dave_benjamin@... <> > wrote:


As a former airline pilot I can attest to the fact that there will be more drag from a turning prop that is connected to a PSA than what you will have from a fixed prop that is not moving.

--- In amelyachtowners@... <> , Kent Robertson <karkauai@...> wrote:

Do those of you with wind generators use them when at sea? Do you see any problems with performance as the boat moves with the seas? I'm not experienced with either wind or PSA generators, but with wind it seems to me the wind is driving the wind generator essentially independently of what it's doing to the sails, unless the wind is coming from astern and interrupting the flow of air on the sails. If you're dragging a fixed prop it wouldn't seem to make much of a difference using a PSA, but if you're using a feathering prop as many are, the turning prop would seem to me to create additional drag.

I'm guessing that just the additional turning of the gears for hours on end would, at some point, create additional wear on them. How much, significant...I wouldn't hazard a guess.

When I do finally get retired and head to the S. Pac, I'll consider both, and solar as well.

This has been a great discussion...thanks to all.
SM 243

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