* Wilbur Hubbard wrote, On 3/28/2007 6:22 PM:
....

The weight is a bit obscene. The battery bank alone must weigh at least
two tons.

That seems a bit high. Plus, the motors are quite light and there's
no fuel tank. And how much does the rig and sails, plus other gear
for a sailboat weigh?


Then there's the array. 100, 100 watt panels at 20lb each is a ton.
That's a ton on the roof so to speak. And it looks like the roof is made
out of 2X4s - more weight up high. Must do wonders for the stability
curve. Oh, excuse me, catamarans don't have a stability curve. It's more
like a stability square. Very good stability till it gets to 90 degrees
then it's over she goes to stay over forever.

You keep saying that, but you seem to have trouble finding cases of
them going over.



One more item: although they talk about doing 5 knots, the log is
filled with entries showing speeds as low as 3.5 knots, and very few
days over 100 miles, even though they had a tailwind much of the time,
plus a quarter knot current in their favor. Thus, they may have only
been getting 3-3.5 knots worth of power from the system.

You must remember photovoltaics make almost no electricity if it's a
cloudy day. Certainly not enough to power electric motors strong enough
to power a vessel.

Actually, the new ones do better on cloudy days, but total output
seems to be the liming factor on this boat. I think its really
designed as a water taxi that would get a shore power charge every night.

The could improve that thing about 50% quite easily
by being able to tilt the roof so the array was always facing the sun.

They are at a low enough latitude so that that's not much of a factor
towards the side, and tipping fore and aft could be a problem.

If they were really smart they could shape it like a wing sail and get
solar and sail power at the same time. Just a thought.

If you could invent a sailcloth that functions as a solar panel, you'd
really have something!