Is Anybody Using a Hybrid Electric Diesel ?

[deckofficer]

For you folks that are using the diesel electric hybrid drive, what props are you using? I would think that the props that could be pitched in reverse, and stay pitched in reverse as you sail, would be better for generating electricity. Am I correct in assuming this?

[Blue Stocking]

Admit I don't know much about the system, but curious, why reverse the props. Won't motors become generators when water driven, a'la Dynastart.

[Hyprdrv]

My Props are 3 blade fixed and yes I regenerate while sailing. Haven't heard this question before and was interested in your train of thought.

Steve in Solomons MD
Lagoon 410 SE

[mbianka]

Originally Posted by deckofficer

For you folks that are using the diesel electric hybrid drive, what props are you using? I would think that the props that could be pitched in reverse, and stay pitched in reverse as you sail, would be better for generating electricity. Am I correct in assuming this?

You might want to check with Beta Marine they have a diesel electric hybrid model and see what they recommend.

[deckofficer]

Originally Posted by Hyprdrv

My Props are 3 blade fixed and yes I regenerate while sailing. Haven't heard this question before and was interested in your train of thought.

Steve in Solomons MD
Lagoon 410 SE

My train of thought is this, with your prop blades pitched in reverse while sailing forward, that would be when you would accomplish the most energy transfer. I think Steve Dashew covered this in his Encyclopedia of cruising. I know a number of sailors will install a separate shaft and prop just for generating electricity. With props like the Max prop, that when placed in neutral after forward propulsion, the prop feathers for minimum drag. If your last engine command was for a astern propulsion and then you return to neutral, the prop will stay pitched in reverse. If any of you are interested, as of today all of my posts are created by using speech recognition software. My keyboard is getting dusty. I have always been a lousy typist, and I just love this program. One really cool feature is that it continually learns your voice. Last night when I initially set it up, it would make a few mistakes. This morning it has been mistake free.

[cbax]

Some hybrid propulsion solution have been introduced in Europe in the last couple of years.
The most effective solution look to be the BlueDrive (rated 7kW) and the SeaProp Flash (rated 5 kW) produced by the italian sister company of Twin Disc.
Thes esytem are used on passenger boats,commercial vessels, sailboats (50 to 150 HP powered)

[gosstyla]

I used Flex-O-Fold and no re-generation - decided disadvantages out weighed advantages.

[mbianka]

Originally Posted by gosstyla

I used Flex-O-Fold and no re-generation - decided disadvantages out weighed advantages.

This past year I've just started to change my operational mode with my EP system. I have a fixed three blade. I start off the mooring drawing 10 amps which gives me about 2 knots boat speed and takes care of any prop drag. As the wind picks up current draw goes down until eventually at around 6 knots regen starts. Happens automatically and helps move things along in light winds. To me it's a win win situation.

[fastcat435]

We use 3 bladed aluminum props with a DAR of 71 % , they regenerate well , up to 4 Kw per motor and we retract the motogens ( pods ) when not used for propulsion or regenerating

[TaoJones]

Originally Posted by deckofficer

For you folks that are using the diesel electric hybrid drive, what props are you using? I would think that the props that could be pitched in reverse, and stay pitched in reverse as you sail, would be better for generating electricity. Am I correct in assuming this?

Assuming one has a variable pitch prop and that a reversed prop will generate most efficiently, the question is, "Is sailing with reversed prop pitch a good idea?"

I think the correct answer is, probably, "It depends." By that I mean that the situation will dictate whether one opts for max sailing performance or max generation.

If the situation is a bracing day of performance sailing and the batteries are already at or near full-charge, it wouldn't make sense to degrade sailing performance by placing additional drag on the prop to generate maximum charging. Indeed, in that situation, Gideon's option of rotating the drives up out of the water is ideal and all capacity to generate is sacrificed to maximum sailing performance.

But if the situation calls for maximum regen, and conditions are such that the vessel is moving through the water so efficiently that placing maximum drag on the prop is barely noticed, then that would probably be the way to go.

I suspect that in most cases it won't be a question of either/or, however, and more of a sliding scale. Until the vessel is close to hull speed, adding additional drag makes little sense. But if the vessel is consistently moving at and above best regen speed, then choosing to have the prop positioned for best regeneration would be acceptable.

TaoJones

[Hyprdrv]

Though mbianka and I have different setups our mode of Operation is the same. We have to bump the throttle off neutral to forward (very slight) to get regen. I'm not sure if this is a "get it going" thing but the Amp meters go from Neg to Poss.
The idea of using folding, twisting, lifting props goes against the KISS idea. I can regen about 2A each motor (2) at 5 knots and I've seen as much as a 8A in the Bay clipping along at 15 knots. know can you imagine surfing down a 15 foot swell in the ocean going 20 knots or more for hours on end? The power you will generate is enough to keep all things electric running. It was done a sister boat to mine Waypoint. First Electric Lagoon Crosses Atlantic to Annapolis...Then Heads to Tortola
They ran the A/C because they where generating so much power. And at over 20 knots I'd be looking for ways to slow down! I think you would need to look at where the boat is going to be used then deside if a increasing the REGEN is really worth the headaches and cost.
Do the math, in most cases a fixed prop might slow you down around 1 knot. what's that over 24 hours? Aren't probably 90% of the boats out there dragging a prop all day long with no benefit?
Yes increasing the Efficiency of the REGEN is highly desirable but not at the cost of an item that may be a maintenance nightmare.
Love the thinking out there, wasn't to long ago B and I where being hunted as witches! )

Steve in Solomons MD

[fastcat435]

Hallo Hyprdv, The Green Motion works exactly the same way as your Solomon system setup , we need to push the throttle forward to get to regenerating, we set the throttle to optimal regenerating since this fluctuates with speed and state of charge with the battery ( is that the same in your system )
The lifting mechanism is wonderful , hydraulically operated with a electric pump and a hand pump for backup. there are 4 GreenCats in the water shortly followed by another 2 due to be launched this spring and summer. You are right that a fixed prop will slow you or us down by around 1 knot and when regenerating that is no problem , we are getting our moneys worth in energy but when we do not need the energy being able to lift the complete system out of the water and the extra knot is really helpfull specially in low wind conditions , doing 5 or 6 is a 20 % speed difference !!
Another advantage is the with the motors out of the water we can point significantly better, 45 degrees app with the props down and 35 with the props up . I am glad you are happy with your system I feel it is wonderfull to cross an ocean with out using any fossil fuel , do the cooking and all else with self generated energy is the future , do you also cook electrically.
While cruising when we need energy we just lower one drive leg and generate ( Depending on speed ) between .5 kwh up to 4 kwh the first with 6 to 7 knots and the 4 kwh with 12 knots of speed. I have seen as much as 5 Kwh at a speed of 15 knots .
Once the batteries are full ( 170 volts ) the motors automatically go into free spinning mode , we get a signal and lift the motor(s) out.
The next boat to be launched has a new type of Lithium batteries that save us around 250 kg of weight and use significantly less space compared with the previously used Mastervolt units and give us 28 Kwh usable power before having to start a generator or 5 Kwh extra.
A real plus.

Greetings
Gideon