Lagoon 440 Diesel Electric Generation

[Eleua]

http://sailmagazine.com/boat-reviews/Lagoon440/

I like this concept, but is it as good as this article lays out?

Good: you can convert energy from the wind to electricity and essentially have a very large power budget while under sail.

Good: the noise from a direct drive diesel is reduced

Good: far fewer moving parts

Good: maintenance has to be a snap

Bad: lots of batteries

Bad: lots of battery related expenses

Bad: when running your electric motors in "generator" mode, you have drag.

Ugly: If your battery charger goes Tango-Uniform, you are going to be one unhappy yachtie.

Ugly: this system has to be expensive

This appeals to me because you can really reduce the amount of diesel fuel you are burning. I'm not "religiously green," but avoiding burning an onboard resource, when it can be replaced by the surroundings is certainly a lofty goal.

Does anyone have any experience with this kind of Diesel-Electric system?

[websailr]

I chartered Waypoint (Lagoon's 1st electric 41 cat with 15kW genset) in Tortola a few years ago. They motorsailed it across the Atlantic (using AC/heat, hot showers, freezer/refr, TV/stereo) & arrived with more power than they left with.

The concept is great, though that boat needed automatic start on the genset since non-tech users ran the batteries flat too many time$$$. In addition they had to add fuel tankage since nobody used it for passages (BVI islands are minutes apart) & users wanted to sit at anchor with AC going. It still was a fine experience to have instant torque - forward or reverse without having to wait for RPM to spool up. You want 2 shaft RPM - no problem, (vs diesel idling at 800 RPM so anytime you are in gear you are moving). Sailing at 8 knots & somebody falls overboard - just pull back on throttles (motors are not in use but ready) & boat stops in 1 boatlength.

Electric motors have double the torque of similar Hp diesel so Emotors can be rated half as big. Fewer moving parts means very high efficiency & more miles for the fuel $.

Yes there is drag during generator mode, but with a double-digit-speed cat, you have the power to do it. Not as good for heavy keelboat. DC motors let you store the energy you make, but with the added weight of batteries. AC is an option & 3 phase is ideal - all the big ships & locomotives use it. I saw a 3 Hp 240V AC 1 phase industrial motor, powered by 5kW Honda portable generator in aft lazarette of a 30' keelboat. He could select any shaft RPM & he had lots of kW to run appliances when not full-speed motoring, plus lots of extra storage in what used to be a crowded engine compartment.

Fuel cells may be economical someday. Hybrid diesel or gasoline over electric is here now, competitively priced, off-the-shelf & greener by 50% or more.