Electric propulsion system for yachts

Electric drive technology has improved vastly and is now already used in cars and buses.

It is possible to see a similar trend in the yachting industry. Electric propulsion systems

can already being applied in yachts. Now, a new and exciting development of this technology

is proposed for the yachting industry: Hybrid drive systems for yachts.


How silent is “silent“?

In the case if marine electric propulsion systems, the definition of silence depends on what the yacht is doing. Batteries do not contain any moving parts, unlike combustion engines, and therefore do not create any noise or vibration. On board your yacht, batteries provide this silent electricity when the yacht is manoeuvring at low speeds and supply electricity for domestic purposes. Underway, engine-powered generators provide the electricity for the electric motors that drive the propellers.

Very quiet, rather than silent.


The electric drive system

The central component of the system is the switchboard, with electricity input from both the conventional generators and the batteries. That electricity is output to the electric drive motors for the propellers, and to other consumers connected to the switchboard, such as domestic systems and bow thrusters, air-conditioning and hydraulics systems used to operate sails on a sailing yacht.


















Designed for silence

The drive system might make sense on paper, but how well does it translate into the environment of a yacht? What constraints apply, and what do yacht designers and engineers need to do differently?

As with any conventionally-driven yacht, the generators and attached combustion engines will require an engine room and exhaust systems. However, there is no need for long propeller shafts and you can be more flexible in the location of the generators. They could, for example, be close to the side rather than central, leaving a large space in the centre of the yacht free for other uses. The switchboard can be located anywhere on board the yacht, but should be in the vicinity of the generators. The batteries can be stored anywhere, but ideally also near the switchboard to reduce the length of the power cables. Finally, the electric propulsion motors will require a suitable space in the aft part of the yacht so that they can be linked directly to the propellers. The most space consuming components will be the dedicated tank for the fuel for the generators engine.


Plug and play options?

The electric propulsion setup described here is flexible, and many items of it can be changed although the philosophy of the system remains identical. The following options exist to either simplify and/or enhance this propulsion setup.


1. No special fuels are used to run the generator sets on board the yacht. Normal diesel fuel could be used.


2. The electric switchboard platform is very versatile, and other sources of electricity can be added to this system. For instance, new battery technology can be added, creating other forms of a hybrid propulsion system. Solar panels can also be connected into this system.