Originally Posted by shadow
Not to sound silly or obtuse, but I thought the whole idea from Lagoon
with the 420 electric motor/charging system was to totally do away with petrol/diesel engines altogether. Seems like if you still need at least 1 generator to keep the balance of power, it seems that a person spent all the money
, and the added weight of the batteries to just have what they could have in the beginning??
Can someone please clarify for me without flaming or sarcasm as I am being serious in my question.. As I was really hoping to have the electric engine/battery charging system be fully reliable by the time I get my yacht...
I'll explain to you the idea.
A sailboat which has got more power from its sails
than it needs to maintain hull speed
can afford some drag from propellors turning generators. So you get a free battery
charge. This charge can be put into a big battery
bank and be used later for propulsion
by electric motors. A generator can be used to put power into the bank in other situations.
The point is that you get silent, efficient power under many circumstances. The hybrid Lagoons were supposed to be capable of silently motoring off their moorings, hoisting sail, sailing and regenerating the batteries, then silently motoring back into port at the end of he day. Neat. And when this scenario doesn't work out for whatever reason, say no wind
, then the generator running at a constant speed and load charging the batteries will still be quite efficient compared to a regular propulsion engine
Without the batteries, however, the whole thing makes a lot less sense. You don't get any power from running the electric motors as generators with your propellors while sailing. You lose power at every stage between running the generator, transmitting electrical
power to the motor, running the motor. The generator motor won't have a constant load. It's more complicated and expensive with no real benefit. If you're not going the full hybrid route
, then you'll be better off with a regular mechanical drive.
In any case, it's very, very hard to beat a conventional diesel engine
driving a shaft. It's a very highly developed, very well-proven and well=worked out system which is very efficient and very reliable.