As we bring our eLite series of yachts to life and as our re-fit business gains momentum, its important to keep an eye on equipment developments. Nova Luxe means “electric done right” and as such we must always offer our customers the best solution for their application. For this newsletter we will share the information we learned evaluating different products.
Parallel Hybrid vs Serial Hybrid for new builds. Deciding which is the better choice depends on the desired performance of the yacht. My position has been that a Serial hybrid system with Torqeedo equipment is the best system for a 35’-50’ power catamaran. This however, assumes that full power would only be used for a short period. Torqeedo does not have a generator powerful enough to support full speed for more than an hour. Max genset size at this time is 25kw and max motor size is 100kw. (quarter throttle speed can be used as long as fuel is in the tank not full speed)
For a serial hybrid system that can operate at its rated motor voltage of say 100kw, you would need to use the UQM system. UQM was recently purchased by Danfoss and we expect the system to get even better under the Danfoss roof. UQM motors and gensets are available at sizes above 200kw. Customers have been asking and it’s possible to do, yet I do not recommend sizing the gensets to fully power the motors. To do so, you would need 4 UQM 100kw motors. One is placed on each shaft and two are placed on the back of two turbo diesel motors (Hyundai ~250hp). Add the batteries and the weight of this system and total cost is high. How long do you expect to operate at full speed? Realistically, this system will float around for years never operating at peak speed for more than an hour. If the gensets were sized for 20-50% of capacity, cost and weight fall significantly. Very simply put by a fellow boat builder, “Boats are like sex, you need to be able to hit that top gear, but you won’t operate that speed much of the time.”
For those who do actually want to run at a high cruise speed for long durations, Parallel Hybrid has greater merit. We have been working with Steyr and Transfluid to develop the proper system. Steyr motors are small, light and will burn anything. The Italian company Transfluid purchased BellMarine about a year ago and are shaping up to be a serious player in the hybrid space. Transfluid offers a clutch that allows one or two electric ‘machines’ of 10-50kW to be attached to shaft. Using the smaller liquid cooled 20kW motors are desirable as they only require a 96v system. Two of those motors will give you the 6-7 knots as electric, just perfect for harbor, channel cruising. When you want excess speed, the diesels can run all day at high speed. This hybrid configuration is about half the cost of the former. Also, the system does not need a generator. We don’t use secret sauce at Nova Luxe so I’ll fill you in on one more trick. The motors are modified by Integral Solutions and 10kw+ alternators are added to the timing belt side of the motor. Two of those will provide 20kW or 50% of that at idle which is more than enough energy to cover the house load and charge batteries, eliminating the need for gensets is a weight and cost saver. Also, the electric machines can generate about 50% of their rated power, providing another 20kw of charging ability while the yacht is underway as diesel. Add solar and this yacht can generate a lot of power, 50kw in an hour! Use both electric and diesel at the same time and the performance exceeds that of diesel motors 100-150hp larger.
For the eLite 50 we will build on spec, I am leaning towards the Transfluid system over Torqeedo because I think it would be better received by the US market. Let me know if you have thoughts one way or the other.
For re-fits, I reserve the serial hybrid option for yachts with bad motors and/or a value near $1m as it takes no less than a quarter million to do the job properly. The Transfluid option would work and that system is closer to $120k. However, two others systems show higher potential. The first I recommend the second I do not (yet). Elco, the oldest player in the electric motor space, has a solid outboard option that reaches up to 50hp or 26kw. They use a 96v electric system which can easily be transformed and shared with the house battery bank. Adding two of these electric outboards to a diesel inboard yacht is a good solution. At $35,000 for the complete system this option has serious potential and I expect to be using more of these units for conversions. The next player which I do not recommend only because I have never seen it working and pre-sales support has been lacking is from Fischer Panda. They offer a shaft driven belt drive motor which has the potential to be the lowest cost solution for electric conversion. It would be the cheapest and easiest to install and if it can be proven effective, the top choice for charter companies looking to market their yachts as electric. If I worked at Fischer Panda, I would avoid the difficult problem of operating the electric motor in conjunction with the diesel on the shaft. I would also give up the ability to generate power. Doing those two things would make the system far more reliable. Issues arise when the electric machine is attempting to generate power from a shaft that spins at different speeds. If the prop exits the water, the shaft could instantly double its speed creating a voltage spike which is difficult to handle. I will keep an eye on this product as it has a lot of potential.
Sailing catamarans with pod drives have some other options. Torqeedo plays in this space but the dominant system comes from Finnish, OceanVolt. They were chosen by Jimmy Cornel for his round the world zero emission trip and I believe youtubers ‘Sailing Tula’ are going with that system as well. We offer either system for our NLS40 sailing catamaran. In fact, we have one used one on the used market ready for such a system! (click here)
Now, because this newsletter is sent to Nova Luxe ‘insiders’ we will fill you in on something special that we will launch later this month. Two more yachts are being added to the Nova Luxe, eLite series, which are a 70’ and 80’ tri-deck. It’s been in the works for a while now however, we needed to properly vet the electric systems for these bemouths and that was just completed. With one exception, a Swiss supplier has proposed a hydrogen solution for the 80’. This team was prepared to build a superyacht using only hydrogen but the project was cancelled at the start of the pandemic almost 1 year ago. Hydrogen was originally a DARPA project but not much has happened with regards to this technology in the USA. I have driven in a hydrogen car and I was underwhelmed with its acceleration. In Europe however, this technology is advancing quickly and the Swiss are at the forefront. Hopefully Nova Luxe will bring the technology back to US shores but for now, we see it as a European offering.
Visit our website for details on the 70’ and if you’re thinking about starting an electric conversion feel free to reach out for advice!
Sincerely,
Marc Hawxhurst
President Nova Luxe
