On Fri, 10 Jun 2005 01:58:55 -0500,
Earl Colby Pottinger wrote:
When talking about long distance travel well designed electric systems have
an advantage I did not see mentioned here. The ability to instantly switch
between motor vs generator lets you do a special type of cruising called
‘regenerative motor sailing'.
Basicy, you set the controller for a fixed speed and start sailing. If the
speed is even a small faction below the average speed your boat would in the
wind conditions then the batteries are almost always in a charging state -
more importantly. If the wind increase/gusts the energy is shuttled to the
batteries instead of trying to speed up the boat to a speed it can not keep -
so you sail on at a steady rate. The wind dies a bit and the motor mode
instantly keeps your speed up - so you sail on at a steady rate. Your boat
starts to surf down a wave - again the generator mode kicks in and the extra
energy goes into the battries - so you sail on at a steady rate. You hit the
face of the wave and you start to climb up and once again the motor mode
kicks in - so you sail on at a steady rate.
Get the idea 
Infact Multihull magazine reports on once setting the right
speed for ‘regenerative motor sailing' all day, enjoying it because it was
so smooth and quiet and still ending the day with more of a charge in the
batteries than when they started out.
Earl Colby Pottinger
http://www.multihull-maven.com/article.php?id=40
http://www.multihull.com/elec_wheel.html
http://www.solomontechnologies.com/news.htm
Thanks for the links.
We are looking at having to repower Windwalker (aging Perkins 107) in
the next couple of years. I don't think that electric is *quite* there
yet, for us, but it's not as far off as it used to be, that's for sure.
If the fuel cells using diesel or methanol were available at a decent
price, that would tip it over the edge for me. I'd dearly love to get
rid of the stinky "iron genny" and getting quiet, and a good recharger
for house batteries whilst underway is a bonus. Plus, even with the
weight of the batteries, I'd likely wind up losing weight by dumping the
diesel engine.
Solomon has some nice rigs, but a bit pricey at the moment. Getting
there though.
--
Jim Richardson
http://www.eskimo.com/~warlock
Gun exchange programs would work great if they gave you a gun when you
handed in a criminal