Community Contribution - Electric Propulsion

The Excess 11 is particularly suitable for electric propulsion.

In my calculations I started from 2x Oceanvolt sail drive 10 Using Deep bleu battery 360V. 40.0 KWh 278 kg If we compare the weight of 2 Diesel engines with 2x 100 l fuel v.s. above electrical drive, then we get a weight saving of about 375 kg. The range of this electrical combination will approximately 60 NM.

Would like to hear your response.

18 comments

I have seen references to a parallel system in one hull and an electric drive in the other. with the weight balance in the e-drive only hull balanced with batteries. gives a ton of options as to how to use the parallel systems. regen, direct drive, using the diesel uncoupled from the drive and use it as a genset. not fully electric, but keeps the options open for passage makers.

Hello One-Pro,
Thank you for your contribution.
Indeed a parallel system is a very good idea! We had mentioned it in the live we had done on this subject. This solution has many advantages but also some disadvantages. We are working on it for our future catamarans!

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Dans une dizaine d'années, le chargement des batteries (ou autres technologies) sera très performant. La quantité d'énergie stockée plus importante. Les moteurs thermiques seront dépassés. Et l'on pourra utiliser cette énergie pour le confort intérieur. Aujourd'hui ce n'est pas encore le cas, on a toujours besoin, à un moment ou un autre, de faire fonctionner un moteur ou un générateur. Je n'ai pas vu d'exemple de longue croisière où ça n'a pas été le cas. A moins, bien sûr, de se priver de tout confort, de pilote, de radar, etc....60 NM, c'est rien du tout dans le cadre d'un voyage.

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First of all, thank you for this very constructive and detailed input on the Excess Lab !

Electric propulsion is, indeed, a major and motivating subject for sailboats, your calculations clearly show the potential benefits in weight (hence performance), not to mention the ecological advantage…
Now, if we were to list the associated obstacles, I would mainly point out :
Initial cost, especially for the battery pack
Limited range (60Nm can be seen as very limited, compared to 2x100L fuel range)
High relationship between range and weather/sea-state (facing wind and see could significantly reduce the theoretical range)
This being said, the Excess development teams are watching those technologies more than closely, things move very fast, and we believe that electric propulsion will be part of our catamaran’s future.

We may make a deeper and more detailed lab subject in the future (it definitely deserves it !). But, beforehand, I’d be glad to receive other inputs and opinions from the community…
Debate is opened, thanks again for putting this important topic on the table !
Hervé Piveteau - Excess Product Manager

I think the same as the poster of first comment. You are right, the range is too limiting. But the solution is to add a diesel generator (maybe 10kW). It means that most of the time, you are on 100% electrical and renewable and if you need it, you can power the system with the diesel generator.

Here, the solution, as used in other Catamaran brands, uncluding a generator, as well explained.

https://oceanvolt.com/solutions/private/multihull/

Is this possible to request with an Excess 11 model?

Something like the OceanVolt system - mentioned above - designed, installed and backed by the boat manufacturer, would definitely tip me into buying a new boat rather than a diesel used boat.

The system would have to be considered as a whole with solar, hydro, and diesel generation included (not optional) in the package. You don't want to "poison the well", with people buying under-specced electric propulsion packages and then being completely unsatisfied.

Agree, this kind of ready made electric setup would be really good!

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And the best would be to remove the gas (security + a lot of problem in case of a world tour) for cooking by installing electro-instruments for the galley... and 220V everywhere on the boat...

I suppose I would prefer for our hopefully upcoming xcs11 the simplicity of the whole setup. Not that much of the all electric miles. But a hybrid setup. Only the DC generator to be maintained instead of two engines + genset. Battery bank enough to run the aircon for the night. No gas. If we end up motoring the DC is on. But having the option of motorsailing with low rpms from the battery bank to ensure the feeling of sailing while cheating.... :D

There are other manufacturers that include appliance that are all 48 volts appliances, and all internal electricity network disfrtibution is 48 volts, to avoid loosing energiu in volatge conversion.

A backup diesel generator is still the best practice, for security reasons.

Some manufacturers as Antares have an interesting approach. Diesel engines are the generators at the same time, when switching to electric mode (engines drived by the electricity, diesel become the generators, then saving the generator having an hybrid system)

If power supply is well handled as many indicated here, it is a far better solution. No vibration and noise, less maintenance, less breakable parts environamentaly friendly and it would be an important differential for XCS. I hope that when you integrate this tech and relocate the helm I have enough $ to be a client.

Just as Francisco wrote, but keep the helm position! :D

Going with electrical motor is also the chance to go for all electric with higher voltages (dc 48V and ac 220V) everywhere. The hot water in the shower can also go electric (no more hot water reserve and less plumbing). The size of some cables can be reduce, much less loss in the cable in general. With all those high energy demanding devices, we will probably need a kind of selection switch somewhere to avoid to draw too much energy from the battery bank.

I have forgotten, if the boat is equipped with electrical motors, the option (which should not be an option) that cost 10.000€ on the Excess 11 to command the motor from both helms should be much cheaper...

YES please - and XCS11 with e-drive, I had this converstion with my dealer and was told "this is a non-starter excess will not make electrical cats". seems there are room for dealer education ;-)
If the xcs11 was available with hybrid e-drive - would be placing a deposit today.
Right now Im looking at other boats and who are willing to deliver with e-drive.

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