Folding Prop VS Regen – Which is REALLY more efficient?

[TitoSoto]

I'm putting all the plans together for my 38' 48v electric sailboat conversion project.

A fixed prop will be more efficient while on power PLUS provide regen while underway. But a folding prop will be far more efficient while underway, without drag and all the complicated (and more expensive) regen electronics.

However, a folding prop is also far more expensive than a fixed one...

So, what would be my best option? Is regen really efficient and at what speeds? Will the motor make noise underway, making my sailing experience far less pleasurable? Do the increased mechanical complications of a folding prop beat the increased electrical complications of a regen system?

[roverhi]

Hope you are not going anywhere if you are into electric. A fixed prop with a regen. system will help to refill that huge battery bank, though. You still won't be able to power more than a few hours at a slow cruise or a few minutes if you use all the power that would have been available from the diesel. A folding prop will do nothing to recharge the batteries and only give you a 1/4 knot or so boost in speed in light conditions under sail. A lot of money for not much return.

[Rick01541]

Also depends on where you sail. If you have a fin keel and sail where there are lots of lobster pots with toggles, a folding prop is the only way to go. A fixed or feathering prop will catch the warps frequently.

[stefano_ita]

hpevs system with fixed prop.

[Captain Bill]

Autostream feathering props. They won't feather from the reverse position so you can use them for regen and feather from forward for low drag. They do cost a bit, but it's just part of the cost of going electric.