The Alerion Express 33’s electric motor is virtually silent while underway.
The Alerion Express 33 is equipped with a Mastervolt Lithium-Ion electric saildrive system that’s quite different than the “hybrid” systems other builders have experimented with. Alerion’s system is comprised of a 7.5kw electric motor and is powered by a pair of 160 amp 12V DC Li-Ion batteries from Mastervolt. The company reports that the boat (with two batteries) has about a 40 mile range under power, and I can report that during a recent test, the motor was virtually silent as we powered at around 6 knots. It took a moment to get used to the almost instant torque the electric motor supplies, and to the fact that you can’t judge the boat’s speed by the sound of the engine revs, but those are two things that are pretty easy to get used to. The system is also reportedly able use the spinning prop to put some power back into the batteries while under sail. However, you’ll probably still need to head back to a shore power cord to recharge the system after a prolonged motor. Have a look at the system in action