Ramona said..
The average yacht sails at 4 knots [4 knot leadmine]. With a 240mm propeller it's going to generate 30 watts! Roughly 2.5 amps. Lets forget about the hp loss needed to get that prop revolving, lets remember there is no free lunch. So for just under 4 grand the average cruiser is going to get 2.5 amps while he is underway!

Propellers are very inefficient when driven. They operate at about 40% efficiency with major losses at the boss and tips in particular. Dragging one though the water the inefficiencies are still there but with added parasitic losses like drag. For 4 grand I could have a pretty phenomenal solar/lithium battery installation, enough to power a modest home!

Now if you were to develop a paddle wheel generator that would be more efficient but the size required would be a problem.

Ramona said..
The average yacht sails at 4 knots [4 knot leadmine]. With a 240mm propeller it's going to generate 30 watts! Roughly 2.5 amps. Lets forget about the hp loss needed to get that prop revolving, lets remember there is no free lunch. So for just under 4 grand the average cruiser is going to get 2.5 amps while he is underway!

Propellers are very inefficient when driven. They operate at about 40% efficiency with major losses at the boss and tips in particular. Dragging one though the water the inefficiencies are still there but with added parasitic losses like drag. For 4 grand I could have a pretty phenomenal solar/lithium battery installation, enough to power a modest home!

Now if you were to develop a paddle wheel generator that would be more efficient but the size required would be a problem.

Stuman92 said..

Look what i found in a Hartley book from 1983

Stuman92 said..

Well turns out the 4.5 evinrude of mine has died, so im going to have a crack at converting it to an electrical outboard that can also work as a drag hydro generator. considering it requires practically no extra "ingredients" it should keep it small and simple.