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African Cats Developing All-Electric Drive for Sailing Yachts

Drawing showing the position of the retractable drive units. Click to enlarge.

African Cats, the Dutch company that last year introduced a hybrid version of one of its lightweight, 43-foot catamarans (earlier post), is developing a full-electric retractable propulsion and generation system for sailing yachts.

African Cats plans to use a 40 kW lithium-ion battery pack designed to provide continuous operation for 12 hours at a speed of 6 knots without any recharging. The company is looking at using li-ion cells from A123Systems or Nanoexa.

Solar panels (4 x 210 Watt) and a wind generator (300 Watt) provide renewable power generation to recharge the battery. When the yacht is under sail, the electric motors regenerate power for the battery pack as well.

Regeneration starts at 5 knots. At 8 knots, 3 kW per motor is regenerated out of the 10 kW drive unit. African Cats is developing a range of 8 different electric motors from 5 kW up to 50 kW. 

The retractable drives reduce resistance while sailing. When extended, the props hang three feet from the hull, and not in the wake of the keel, enabling a better water flow.

African Cats is currently testing the system with 10 years of simulated usage in its salt water testing facility in Durban South Africa. After 3,000 hours of total run time, the company will disassemble the units to check for wear. Concurrently, it is building the first FastCat 435 Green Motion (no hybrid) and at the end of this year will complete two Atlantic crossings for further testing.

The retractable Green Motion drive system will be made both for monohulls and catamarans.


Kit P

Wow, this is a HEV that I could like. Since a sail boat already needs a ton or so of lead ballast, the wight of the batteries could be designed into the hull.


What a beautiful combination of ideas. They say it is lighter and therefore faster than their diesel configuration. Plus it is a much better boat with no noise or diesel smell. Cool that there are three difference ways to charge the battery: solar, wind and hydro. That would ensure that the system is fully charged in most types of weather. Again it is durable light weight batteries that make this boat possible more than anything else, followed by high yield solar panels. The rest is old technology.


Is that really a 40kW battery running for 12 hours? Or is that a 40kWh battery? If the former then that is one serious battery $$$$$!! Heck, even a 40kWh battery is big bucks, but then boats are anyway.


You could take a 4 man inflatable, a trolling motor and an awning made of solar panels and go all day.


Boats with these emerging technologies will make the
liveaboard experience much more practical in remote
places. Onan generators and the like, have proven
to have reliability issues as well as maintenence on
the fly problems. Plus the benefit of not carrying another
fuel on board. LPG and propane are hazard enough carried,
top side, in canisters. This expensive up front cost would
be more practical as boats loans are usually of
considerably longer duration than car loans. Plus the
write off as a second home on interest paid would help the
market penetation of Li-ion Battery technology. The more
unique applications like this, and the costs will become
more competetive making the ICE seem expensive over its
projected life span. The more wealthy Yachtsmen that become the
early adopters of this tech, will enable us boaters on a budget
to have this clean tech in our grubby little mitts sooner.
And the waterways will be cleaner as a result. Now, you just
need an on board desalination unit to then strip
out the Hydrogen so that you can run a fuel cell to
power your stove and air conditioning unit when you
need intermittent peak energy demand. This will make boat fires
a little more diecy however. Gives the term "Jump Ship" a "hole"
new meaning. All aboard?

gideon goudsmit

I read the comment on the New Green Motion FastCat 435

The cooking is done on Induction plates so that is also fossil fuel free , the water maker that comes standard is a low pressure type that consumes 23 amps 24 volts and it gives 18 gallons per hour
there are no more fossil fuels on board , not even candles that have been replaced with led look alike candles by Phillips Imageo

This whole setup up is just a bit more expensive than the normally used diesel engines


Make the sails out of the new nanosolar mylar thin films and you are in business.


what is the battery voltage, 12 or 24?

We’ re off! In Miami right now, waiting for our flight to San Juan to leave. Tomorrow we board Regal Princess and start a 10 day Panama Canal cruise. Along the way we will be visiting Aruba, Puerto Amador (Panama), Puntarenas (Costa Rica), Puerto Quetzal (Guatemala), Huatulco (Mexico), and finally Acapulco (also in Mexico of course).

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