Propulsion and Equipment

It’s a fact: to cover its daily energy consumption, a comfortable 40 to 50-foot cruising multihull (i.e. one with refrigerators, induction cooktops, multimedia equipment, a washing machine and maybe even a dishwasher) has to run one or even two of its engines (or a generator) for several hours during the day. If you use electric winches and air conditioning (by a long way the biggest consumer on board) a lot, recharging the batteries becomes a real issue. So, from there to powering electric motors, it’s not a foregone conclusion! And yet, more and more boaters are opting for a quiet and clean life at anchor—even when it’s not required by local legislation.

Non-polluting energy production, previously an environmental imperative, is becoming a societal demand and sometimes even a regulatory constraint. All these factors are motivating equipment manufacturers to perform better in order to offer the same level of comfort without polluting.

While everyone seems to agree on the need to reduce carbon emissions, when it comes to putting this into practice, many boaters still seem to have strong preconceptions about electric motors. They are criticized for not being fast enough, for the need to carry a very heavy battery bank, for more complex on-board energy management, and above all for its prohibitive price (between 25 and 35% of the total price), which is enough to deter even the most fervent environmentalists. However, technology is advancing, so let’s take a look at the new trends among manufacturers in the industry.

Pods Are all the Rage!

Manufacturers who have designed an architecture incorporating electric propulsion as standard, such as Silent Yachts and Windelo, generally opt for shaft-driven props. Millikan Boats, in redesigning its M.9 into the M.10, has adopted just such a transmission system, which offers many advantages as it is simple, easy to maintain and offers optimum efficiency.

However, the largest manufacturers haven’t necessarily anticipated the transition to electric power. For them, it’s more a question of replacing internal combustion engines, which were most often installed with saildrives for reasons of living space. Pods are proving to be a good solution. Attempts to replace diesel engines with electric motors while retaining the same transmission have not necessarily been successful. Proof of this can be seen in Excess’s approach: the smooth running of its prototype Excess 15 was hampered by the noise generated by the saildrive mechanism (usually masked by the sound from the diesel motor). On board, the whistling noise was almost unbearable. The manufacturer therefore reviewed its process, and the Excess 11 Hybrid is now equipped with Oceanvolt pods, eliminating the noise pollution. It should be noted that on these pods, as on those from Bellmarine, Seco Marine and Torqeedo – a brand that came under the control of Japanese manufacturer Yamaha in 2024 – the motor is located in the hull. However, on the system ...