Hybrid Electric Propulsion for Sailboats
Most of our owners go fully electric and never look back. Some want more range than a battery bank can give, and some have boats too heavy to push to hull speed on electric alone. For them we build two kinds of hybrid, both on the same 48V Powerflow system.
Option 1: Electric drive with a DC generator
The boat runs on electric all the time. A small diesel generator sits in the engine space and charges the 48V propulsion bank directly when you need it, with no charger in between and nothing lost to conversion. Most days it stays off. On a long calm passage, it's the reason you can keep motoring. We have three of these systems shipped and being installed by their owners now.
In real numbers, a Passport 40 at 5 knots pulls about 110 amps from the bank, and the 6 kW generator puts out 125. With the generator running, the boat can hold 5 knots while the bank stays where it is, on a little over half a gallon an hour.
The 6 kW unit is built on the Yanmar 2YM15 and the 15 kW on the Yanmar 3YM30. Both come in a sound-shielded stainless case, share cooling with the motor system and show up on the Powerflow display. Full specs are on the DC generator page.
A walkthrough of the Charge 15: controls, fuel, power, exhaust and coolant connections, and each service panel.
Option 2: Parallel hybrid (P22)
Here the electric motor and a diesel engine both drive the same shaft. You run on electric for everyday motoring, getting off the dock, moving through an anchorage or working up a channel. When you need serious power for long stretches, the diesel takes the load.
It fits two kinds of boats.
- Heavy sailboats. Above about 35,000 lb, a single electric motor can't hold hull speed for long. The diesel can.
- Powerboats. Use the diesel to get up on plane and cover distance, then switch to electric for anchor hopping, channels and getting in and out of anchorages without noise or fumes.
Looking for a founding owner. The P22 parallel hybrid design is complete, and the first production build is waiting on the right boat. Founding owners work directly with our engineering team on the final configuration. If that's you, say so in your build slot application.
Do you need a hybrid at all?
Maybe not. We crossed from Mexico to the Marquesas on our own Passport 42, Gemini, with no diesel and no generator. That was 23 days on solar, regen under sail and a 33 kWh bank. A lot of boats are better off with a well-sized battery bank and a skipper who's willing to slow down when the wind quits.
A generator makes sense if you plan long motoring legs, cruise where solar is weak, or just want the margin. A parallel hybrid makes sense if your boat is heavy or you need to plane. Look up your boat on Boats We Convert to see how far it goes on electric alone, and we'll talk through the rest on the fit call.