Hybrid Sailboat

A French catamaran offers a different approach to power and propulsion

The novel part of the Lagoon 440 is its propulsion system—it’s a diesel-electric hybrid. Twin electric motors, one mounted in each hull, power the boat. They turn the props at 900 to 1,100 rpm at cruise, an ideal speed for efficiency in this size range. Energy for the motors comes from a 22-kW diesel genset which charges a massive storage bank equivalent to twelve 8D-size batteries. (The extra weight of the batteries is compensated for by the lack of two heavy diesel engines mounted near the sterns and by the ability to mount the battery weight closer to the center of the boat.) The batteries are wired in series to give 144 volts. It’s similar to the system in a hybrid car, the genset starts automatically when the batteries need recharging. This happens at 50 percent to 80 percent discharge and is adjustable.

It also has the equivalent of regenerative braking or coasting in a hybrid car. In a hybrid car, braking or coasting downhill puts the motor into generator mode, recharging the batteries. In the Lagoon, sailing in a good breeze makes the props turn the drive shaft as they move through the water, cranking the motors and generating electric current from them. That recharges the battery bank.

It works well on open-ocean passages, not so well in light winds. In strong winds so much current is generated that the control system shut off the motors and stopped the props to prevent overcharging the batteries.

Price: $500,404 for the three-cabin, three-head Owner’s version includes standard diesel engines (electric propulsion system optional), sails, and delivery (but not rigging, launching, or taxes) to East Coast USA.

Builder: Lagoon America, Annapolis, MD; www.lagoon-america.com, 410-280-2368
Designer: Marc Van Peteghem & Vincent Prevost
Construction: Hulls and decks are hand laid and then vacuum-bagged to ensure light weight and complete resin infusion. Hulls are solid fiberglass below the waterline. Closed-cell foam core is used above the waterline to minimize weight and provide extra stiffness. The deck is cored with balsa, and areas where deck hardware attaches are reinforced with solid glass. Rig is aluminum.
Pros: Nearly silent under power, better weight distribution, better fuel economy.
Cons: Only one power source (for electricity and propulsion) instead of the redundancy two separate engines provide.

LOA - 44'8"
LWL - 41'10"
Beam - 25'3"
Draft - 4'3"
Displacement - 23,148 lbs (empty)
Sail Area - 1071 sq ft (main and jib)
Fuel/water/waste - 172/237/50 gals
Power - 22kW genset, 2 Solomon Technologies electric motors
Electrical - 12 8D batteries
Displacement-Length ratio - 162
Sail Area-Displacement ratio - 15 (100% foretriangle)

Resource: Lagoon 440, SailMagazine.com

Cost of fuel really isn't of much concern for owners of this boat. I'm don't think you could justify the cost based on fuel savings, but it could increases the (power) range which is a significant consideration.

Comments

[Stephen Boulet]

This would be a serial hybrid then? It's interesting to see how this gets used in different applications. I like the fact that the batteries can be recharged regeneratively. I wonder what the energy storage capacity of the batteries is, and how long the boat can be operated on battery power alone.

Stephen

[DG]

I'd love to see more on this, as my completely non-technical self thinks diesel-electric hybrids, and eventually diesel-electric-plugin-hybrids running on B100 biodiesel are the solution to our liquid fuels crisis (like how I use that phrase to sound all technical when I obviously don't really know what I'm talking about?).

However, I've heard that diesel-electric hybrids don't gain much efficiency because of how diesel engines work. Does anyone know if that's true?

[JD]

It would actually be usefull for boating. Good marine diesels are heavy duty affairs due to the load requirements. Using a hybrid system would allow decoupling of the diesel from the propulsion train. This would allow using the new, smaller block engines made for auto's (not a good choice for direct propulsion because of the load requirements which negated traditional longevity bonuses expected from diesels).

As far as fuel effeciency. Allowing the engine to operate at an optimum, steady load would only enhance this. If curiouse I'd advise checking out some of the boating forums related to diesels.

[Demesure]

But most of the time, a boat is at a steady load, we are not talking about turbo overdrive on roads!
- If it is to take advantage of regenerative braking, it's NON existent with boating.
- If batteries must be charged for an electric motor for port maneuvering, so there would be no need for a diesel or gas motor.
- If it's to save oil when you can spend near 1/2 million $ for a boat, you can spend some buck to fill the tank
- If it is to save money, than buy a much cheaper standard catamaran with a classical motor. No one with all his mind would hope to recoup the over investment of an hybrid, even when supposing no more maintenance cost of a non standard solution.
- If it is to prove your green credentials and the size of your purse, bingo.

As a sailing lover, I let this kind of scam to others. Far out of my budget anyway ;)

[brian hans]

why arnt they dropping a propeller in the ocean and for a bit of drag, produce all the recharge e' from the sail's power?

it seems like a no-brainer idea.

[Hans]

I like the idea, on the other hand sailboats are perfect renewable energy designs no matter what motor lies beneath.

Install paddles, that would make a real green hybrid :-)

[Mark]

Yes, the prop can turn under sail and generate power to recharge the battery. That's the regeneration concept.It cannot work efficiently under "braking" conditions unless you installed a big and heavy flywheel

[Jeff]

It's a bit excessive if you ask me. Sailboats are already hybrids, and typically use very little fuel. That's a very expensive setup to squeeze a tiny bit more savings.

I have a 22-foot sailboat and will burn about 3 gallons of fuel on a typical year. Spending a lot of money to reduce that would be silly.

If you're a sailor who motors everywhere (and they do exist) it might make sense.

[Kay T.]

That is one good looking boat, I kind of think that the cost of the craft would take awhile to recoup the savings in fuel expenses. However,you would probably have to be rich to buy a boat like this to start..would be nice.
Kay T.

[David Tether]

Sorry to see this so late. The props do regenerate while sailing...The Disel Electric are not that efficient, but the Hybrid Diesel Electrics are about 40% more efficient without the renewable inputs...with them they are off the scale in terms of efficiency. There have been boats that sailed for days (19 days to be exact) without using a drop of fossil fuel and made all their energy with regen from props.

[Joseph Huberman]

I have a Wyle 43' hybrid sailboat, Prestissimo. It is a monohull sloop. I've sailed her along the east and west coasts, about 6000 nm in the last three years.

In my experience, and in my opinion:

The number one advantage is low noise. So quiet that sometimes if I am motorsailing in 5kts of wind, and then the wind picks up say to 10-12 kts, the water and wind noise masks the motor & genset. Motoring doesn't interfere with listening to music or having a normal conversation.

The main advantage of the regenerative ability is that sailing only 4 kts generates enough power to run all the regular systems including refrigeration, computer, radar & instruments. If the boatspeed picks up to 6 kts for much of the day there will be enough to charge the batteries to last the night. I haven't gone for 16 straight days without using the genset, but it isn't uncommon to fully charge the batteries in a day of sailing.

The third big plus is that with the electric drive and a battery bank I am always ready to power up instantly. I can do all my anchoring, docking, and holding "head to wind" without having to start the generator. If I get into unexpected trouble I have motor power ready with the flick of the throttle.

My battery bank will run the motor at full power for an hour. Obviously, if I am going to motor for a while I'll turn the genset on before I run the battery bank down so I always have a significant power reserve if the diesel engine shuts off. I have the equivalent of 1000 amp hrs at 12v. When it is fully charged, I can live aboard for two days before it is depleted to 50%.

I hope this answers some of your questions.

Joseph Huberman

[Kit P]

JH, nice report. I wish I has a nickel for every time I started my engine just to be safe because when light wind does not provide enough speed to get out of some yahoos way. Anything that contributes to quiet and stress free sailing.