There was an article on the Chevy Volt in this month's Car & Driver (I know, not a sailboat, but it is a plug-in hybrid.) They discussed how to give the battery
pack a life of 10 years or 150,000 miles, it could never be charged above 80% or be used below 30%. Once it hit the 30% mark, the gasoline engine
kicked in and ran the car while charging
The aquatic electric drive systems I've seen have still used standard lead-acid batteries, which are heavier and less efficient. I can't believe that you'd get more than 4 or 5 years maximum out of the at least $1,000 of batteries you'd need to have any sort of range.
IMHO the propeller
rotation during sailing is never going to fully charge the battery
pack. Likewise, by my estimate, it's going to take at least $2k in solar panels
to be able to charge that many batteries in a day and probably more like $4k - $5k in panels
to be able to run the boat off solar
on a sunny day while charging
. That's a big investment for panels
that are going to be taking up too much deck
space and can be easily broken by flying debris or plain clumsiness.
I think a hybrid diesel
electric is the only feasible alternative at this point because neither battery life nor solar
technologies have progressed far enough yet. Unfortunately, there's no incentive to go that route
because it's still cheaper to rebuild
an old diesel
and keep running that. From what I can tell these hybrids are at least $10k+. If not, please steer me in the direction of a more affordable one.
To go all-electric, it seems to me that a heavy duty electric motors only run about $500 from a supplier like National Oilwell Varco. With that you need an on/off switch, a knob or lever to adjust resistance and polarity (this adjusts the speed and direction of the motor). You'd also need a charge controller to monitor
the batteries and cut off charge when they're full. What all those mystery electronics
are in those black boxes and why decent all-electric kits seem to start at $7500 without the batteries, I don't know. I guess you're paying for the pre-fabbed brackets, housings, and gears to mate it to your prop shaft, etc. Once you add batteries and solar, you're still in the $10k+ range.
I'm wondering if anyone has been brave enough to just put together their own hybrid with off-the-shelf parts
and a portable generator. Seems like it might be doable for around $3k - but maybe I'm just oversimplifying it all in my head