Prop Shaft Generator

[RickBowman]

Has anyone seen or heard of a generating unit on a prop shaft on an inboard diesel?

[sailingdog]

I have... the problem is that some transmissions don't like to have the prop freewheel. Otherwise, you can add a sheave and a belt to the prop shaft and use it to turn the generator.

[JouvertSpirit]

I would be more concerned if the drive was hydraulic or mechanical. Hydraulic should do fine cruising under sail in neutral. I think the newer Yanmar smaller HP (20 or so) use hydraulic transmissions. Great idea. Now I have to start thinking about a trickle charger and another mod...

Of course unless your stuffing box is perfectly set, you will be getting a drip with shaft rotation.

[Valiente]

I have to wonder if putting a generator/pulley off that shaft might not cause wear or scoring due to the offset lateral force. I've seen pictures of it in old sailing books, but not in recent years.

[sailingdog]

Valiente—

I think the reason it isn't seen much nowadays, is the advent of solar and wind generators that are relatively affordable and reliable. Of course, any generator running off the propshaft would also yield power during any period of motoring.

[PBzeer]

It seems, the thing to remember with any alternative power source, is that there are no free lunches. They all have various trade-offs, some moreso than others, and it really depends on the boat and the systems it has on it. What works for one, won't necessarily work as well for another.