On Thu, 02 Jun 2005 10:13:43 -0400, rhys wrote:

On Thu, 02 Jun 2005 12:43:35 GMT, (Mic) wrote:

Perpetuated Motion
Electric propulsion for boats: A century-old technology may just be
the wave of the future

LINK:

http://www.cruisingworld.com/article...ID=396&catID=0

" Advocates for diesel-electric propulsion list among its virtues that
it's clean, quiet, efficient, and requires very little maintenance.
Another advantage frequently noted in connection with the STI system
is the ability to make electricity--to "regenerate"--when the boat is
under sail."

"While internal-combustion engines are typically described by their
horsepower rating, STI's motors are named for the torque they develop.
An ST 37 puts out 37 foot-pounds of torque or 6 horsepower; Tether
recommends using it on monohulls up to 32 feet and 10 tons or to
replace diesel engines of up to 24 horsepower. An ST 74 puts out 74
foot-pounds of torque or 12 horsepower; Tether recommends using it on
monohulls up to 50 feet and 16 tons or to replace diesel engines of up
to 48 horsepower."

The ST37 is right in the range for my current light cruiser, and the
ganged ST74 is appropriate for my anticipated next boat, which would
be a modified full-keeler.

I'm watching this technology like a hawk. It makes a lot of sense on a
number of levels, but of course, it isn't for everyone.

In the meantime, I'm replacing the exhaust end of my old Atomic 4....

http://www.soundingsonline.com/stories.html?story=2

"Waypoint carries twin 12-hp Solomons Technology ST 74 electric motors
powered by a dozen batteries. The batteries' charge is renewed by
leaving the power plants running when the boat is sailing so the props
turn in the water, transforming the electric motors into an electric
generator. If there's no wind, a 15-kw diesel generator recharges the
batteries, says Mike Stevens, Catamaran Company's Annapolis salesman.
Stevens says Waypoint can run four hours at 8 knots on batteries, or 6
to 10 hours at 5 or 6 knots. He says the electric-powered cat appeals
to the company's most environmentally conscious customers. "They want
to sail with a green wake," he says."

R.

Mic wrote:
....



http://www.soundingsonline.com/stories.html?story=2

"Waypoint carries twin 12-hp Solomons Technology ST 74 electric motors
powered by a dozen batteries. The batteries' charge is renewed by
leaving the power plants running when the boat is sailing so the props
turn in the water, transforming the electric motors into an electric
generator. If there's no wind, a 15-kw diesel generator recharges the
batteries, says Mike Stevens, Catamaran Company's Annapolis salesman.
Stevens says Waypoint can run four hours at 8 knots on batteries, or 6
to 10 hours at 5 or 6 knots. He says the electric-powered cat appeals
to the company's most environmentally conscious customers. "They want
to sail with a green wake," he says."

R.


This isn't a bad setup for a charter boat that takes short hops, but a
32 mile range on the battery charge is a bit limiting. I'm guessing
that the genset doesn't come close to keeping up with the drain, so
this really isn't a "diesel electric." However, on a lighter
catamaran, the number might workout better.

I look for the 'pertinent omission' in marketing data and hype.
Sure one can argue the 'green' attributes of such a system; but, one
surely HAS to look at the all that additional weight for the batteries
and control systems. With such a boat much deeper in the water and
dragging a three bladed fixed prop .... it HAS to take MORE overall
energy to move such a boat. The boat is now much deeper in the water
and freewheeling a gigantic prop ...... of course you now need a bigger
boat that goes slower. As far that the 'energy balance' ..... I'll
bet its a 'wash' thus no clear advantage. Batteries dont last forever
and I wouldnt want the replacement bill for such 'monsters' added to my
cruising kitty.
I'm more keen on the Pardeys 'engine' choice when it comes down to
'efficiency'.


In article , Mic
wrote:

Perpetuated Motion
Electric propulsion for boats: A century-old technology may just be
the wave of the future

LINK:

http://www.cruisingworld.com/article...ID=396&catID=0

" Advocates for diesel-electric propulsion list among its virtues that
it's clean, quiet, efficient, and requires very little maintenance.
Another advantage frequently noted in connection with the STI system
is the ability to make electricity--to "regenerate"--when the boat is
under sail."

"While internal-combustion engines are typically described by their
horsepower rating, STI's motors are named for the torque they develop.
An ST 37 puts out 37 foot-pounds of torque or 6 horsepower; Tether
recommends using it on monohulls up to 32 feet and 10 tons or to
replace diesel engines of up to 24 horsepower. An ST 74 puts out 74
foot-pounds of torque or 12 horsepower; Tether recommends using it on
monohulls up to 50 feet and 16 tons or to replace diesel engines of up
to 48 horsepower."

Rich Hampel wrote in
:

Batteries dont last forever
and I wouldnt want the replacement bill for such 'monsters' added to my
cruising kitty.


Although they are VERY quick to point out to you that a Toyota Prius
battery pack is still under a long warranty to sell the cars....If you
wander back into the parts department and ask, you'll find out WHY they are
VERY quick to point out to you that a Toyota Prius battery pack is still
under a long warranty....................to sell the cars......

Bring out SEVERAL other thousand!

Waste Marine and your local brokers must be very jealous....The markup on
Ni-MH battery packs must be MOST impressive....

If you factor in battery pack replacement, operating cost is about the same
as a Cadillac Escalade with a Northstar Beastie.

Mic wrote:
Perpetuated Motion
Electric propulsion for boats: A century-old technology may just be
the wave of the future

LINK:

http://www.cruisingworld.com/article...ID=396&catID=0

" Advocates for diesel-electric propulsion list among its virtues that
it's clean, quiet, efficient, and requires very little maintenance.
Another advantage frequently noted in connection with the STI system
is the ability to make electricity--to "regenerate"--when the boat is
under sail."

"While internal-combustion engines are typically described by their
horsepower rating, STI's motors are named for the torque they develop.
An ST 37 puts out 37 foot-pounds of torque or 6 horsepower; Tether
recommends using it on monohulls up to 32 feet and 10 tons or to
replace diesel engines of up to 24 horsepower. An ST 74 puts out 74
foot-pounds of torque or 12 horsepower; Tether recommends using it on
monohulls up to 50 feet and 16 tons or to replace diesel engines of up
to 48 horsepower."


This is cool. But, lead acid batteries and high voltage DC and salt
water are like rocket fuel, deadly as chlorine.

A Canadian (British) submarines had a fire recently that seems to
point to the biggest drawback.

Lithium iron batteries are way dear, yet.

The steam idea; now what if, when you made hydrogen electrically
from water, instead of throwing away the pure oxygen, you stored it
and then introduced it into an I.C. engine that burned hydrogen?

Would that be a steam engine? How efficient and how large or small
could such an engine be?

I know, we haven't figured out how to corral big lumps of H2, yet,
but who knows what will come along.

Isn' it unfortunate that we cannot yet efficiently derive
electrolyzed O2 as a liquid? Can hydrolysis occur at very cold
temperatures, under pressure? Seems to me it shouldn't matter too
much, as the atomic bond of water might not be bothered much by
ambient considerations.

The nicest thing about all that is that if you spring a leak in the
system, the water around the boat might get cold enough to walk on.

'Gorra, If gasoline is dangerous on boats, how about pressurised
supercold O2?

Oh, and sails inflated with H2?

On subject, the balance in such a subj. electrical system, it seems
to me, would be a 5 hp charger and a 20 hp, 20 minute battery drive,
or about that. In a blow at sea, no self respecting sailor would
prefer to rely much on the engine, when the wind is so free, if
wild. Any sailboat that cannot sail might never expect to be able to
power out of a storm.

I still want to know how an engine would work if it dispensed cold
instead of heat. Liquid nitrogen is more benine than gasoline, and
could be used to suck heat through an engine if the heat source is,
let's say, relatively infinite, being represented by the enormous
heat stored in the liquid water of the sea.

It's heat would vapourize the LN2, providing gas volume to be
harnessed in an "external combustion" steam type engine, leaving in
it's wake only cold water, perhaps even ice, and still cool nitrogen
gas. Just think, free air conditioning as a side effect!

All that is lacking is a cold temperature LN2 low volume injection
pump of some sort, to introduce LN2 to a heat exchanger, boiling the
LN2, providing overpressure and volume to drive a piston.

A small bore, cold environment injection pump could generate a large
volume of cold gas in a heat exchanger which would gain power from
being warmed by the sea.

A leaking LN2 tank (dewar) could asphixyate cabin occupants, so must
vent overboard. Anyone being asphixyated by evaporated liquid
nitrogen would likely wake up from the increasing cold before
expiring. If half of the nitrogen and oxygen in a cabin were
replaced by pure cold nitrogen, the ambient temperature would freeze
the nose and the water in the exhalations passing through your nose.
When it gets that cold, all your nasal hairs freeze together and
pull on one another, causing pain, and that should wake you up
before more than half of the oxygen is displaced from the room. Ask
any musher about that cold effect.

You can make your own liquid nitrogen. All you need is a good
compressor and a heat exchanger, which stores potential energy in
the form of a temperature differential, in the environment and an
insulated cold tank until you want it back. Using a windmill to pump
air to provide storable LN2 might even work.

Terry K

Well. I am a real fan of eletric motors for boats. And while the distance I
travel on the lake the to and from my cabin is not that great (about 2.5
kilometers per trip) I got sick and tried of the old two stroke and the work
needed to get it going. On very cold days, it could be murder to start - and
let's not mention the mess-ups in oil ratios when my brother tried to use it
a few times.

The four stroke honda works great as long as I don't do something stupid and
end up flooding the engine, then it takes up to 15 minutes before it will
start. Atleast I finally learnt how to flush the water filter.

The electric motors - perfect first, perfect always. Generally I get about 4
trips out of the main battery (I have a smaller backup incase) and if I
remember to plug in the main batteries from the cabin to recharge boat's
battery before I go to sleep, it is always ready in the morning.

To me however the biggest advantage is the quiet. Set at lower speeds the
motors as so quiet that even beavers which are in the water and would notice
an loud sound do not hear me coming. I can visit the loon's nest without
driving the parent birds away, I get far closer to animals on shore with the
electric than even with paddles.

-----------------------------------------------------------------------------------------------------------------------------------------------------

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

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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

Jim Richardson :

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.

Have you looked at Honda's generators with invertor output?

For the power out, those machine are very quiet. While the largest model I
have used is only 2.5KW it is my understanding that all the models are very
quiet in operation. More than once I had to personally go and check my unit
to see if it ran out of gas because I could not hear it running. And that is
another thing, depending on your needs the ecomo mode uses very little gas to
run. Let's me set my charger to slow charge the batteries (best for life and
completeness of charge) without wasting gas producing more power than is used.

Earl Colby Pottinger


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