Test / Navigation and Program of Silent Yachts 55 E-power+, sailing silently and without pollution

We tried the Silent Yachts 55 E-power+ in the bay of Cannes in light wind. Its more powerful motorization than the first two versions convinced us for cruising without CO² emissions.

The most powerful motorization

The Silent Yachts 55 is available in three different power versions:

  • 2 x 30 kW with 20 kW generator
  • E-power with 2 x 135 kW with 100 kW generator
  • E-power+ with 2 x 250 kW with a 100 kW generator and a 210 kWh battery bank.

Solar energy is supplied by about 30 solar panels with a peak power of 10kW. This means that on a nice summer day, the recharge can reach about 100 kW. Considering that in the first and last hours of the day, the angle of the rays, at less than 20° is not sufficient, maximum recharging will be more efficient in the summer and much less on days of high cloud cover.

Essais en mer du Silent Yachts 55
Sea trials of Silent Yachts 55

A much more interesting potential

Une belle vitesse de pointe.
Nice top speed.

While the first two engines and energy stocks do not allow a "carbon free" speed higher than 4-5 knots and correspond to a rather slow cruising mode, this E-power + version promises us a top speed of 14 knots, but above all allows us to reach 8 knots over 50 miles without having to switch on the generator. With the torque delivering its full power instantly, port manoeuvres are very reassuring. Once out at sea, we set off and check the consumption on the digital control panel and we see that the consumption is exponential as soon as we push the handle on the... watts. While 2kW are needed in the port, as soon as we reach a cruising speed of 8 knots, the needle rises to 30 kW allowing only 5 or 6 hours of navigation. But this is more than enough to cover the 40 miles that usually separate two calls. And if you drop to 7 knots you can cross to Corsica just with the help of the photovoltaic for 15 hours.

Une surveillance depuis le poste de barre
Monitoring from the helm station

A board that controls everything

L'électronique en appuie du pilotage.
The electronics support piloting.

As soon as you accelerate, at 10 knots, you need 100kW and from 11 knots, you have to start the generator, because the consumption exceeds 150kW unless you set the settings on the panel. It allows you to command and control the energy, whether it concerns propulsion or life on board, but also recharging. It calculates, based on the instantaneous consumption, the right moment to automatically start the generator set so that it never runs out of power. If you keep a speed of more than 10 knots the generator will start by itself after half an hour, whereas if you make 7 knots you will have about 15 hours ahead of you. In fact, the consumption is exponential and a small knot or just going upwind costs a lot of energy, you have to get used to it.

An offshore cruising autonomy

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