On Sun, 21 Nov 2010 05:33:59 -0800 (PST), Joe
wrote:

Do they mention the difference from a chained shaft to a free
wheeling prop. I've heard a chained non turing prop provides less
drag.

Drag is only part of the issue. How much recharge power do you think
can be extracted by the spinning prop?

In article , Wayne.B wrote:
On Sun, 21 Nov 2010 05:33:59 -0800 (PST), Joe
wrote:

Do they mention the difference from a chained shaft to a free
wheeling prop. I've heard a chained non turing prop provides less
drag.

Drag is only part of the issue. How much recharge power do you think
can be extracted by the spinning prop?

According to the author of the article (Yachting Monthly's technical
editor, I'm sure he's not overly gullible) and the photo he published,
at 8 knots they were generating 4kW.

This is cutting edge stuff, most anecdotal rebuttals here have been
based on old ideas and technology. Here's a bit more about it:
http://www.matternetwork.com/2010/11...f-cruising.cfm

Justin.

--
Justin C, by the sea.

In article , Joe wrote:
On Nov 20, 1:20?pm, Justin C wrote:
In article , Bruce wrote:
On Fri, 19 Nov 2010 23:34:40 +0000, Justin C
wrote:

quote
? ? ? ?The GREEN MOTION system eliminates fossil fuel used by sailing
yachts in any way. Electrical energy is generated with the system and is
stored in batteries (lithium Iron Phosphate are optional). It will
generate sufficient energy to be used for propulsion, hot water, cooking
and all electrical equipment and navigation on board. When batteries are
fully charged or high speed is required (race) the lifted Motogens
eliminate the drag from the propulsion system and this increases the
speed of the yacht (between 5 - 15%).

? ? ? ?Retractable Motogen
? ? ? ?The electric retractable Motogen is new, light
weight, extremely efficient and better than any propulsion system ever
designed for yachts. Usable in all sailing yachts from 30 to 90 ft (9-30
m): monohull, catamaran or trimaran). Installation can be made inside
the hull in a monohull or on a retractable arm for multihull. 5 years of
extensive testing has been done with a ?proof of concept? sailing in
excess of 10.000 Nm.
/quote

URL:http://www.green-motion.com/

I suspect that the estimates of ?drag versus speed for the generator
propeller is highly optimistic. The best estimates I can find are that
the drag from a 3 bladed prop reduces speed by about 15%, not the 5 -
15% mentioned.

They put a small amount of current through the motors as the same time
as using them to generate, this partially compensates for the drag -
according to last month's Yachting Monthly feature.

? ?Justin.

--
Justin C, by the sea.- Hide quoted text -

- Show quoted text -

I guess they could not afford a CVP prop to reduce drag when needed.

When not needed the motogens lift clear of the water entirely.

Justin.

--
Justin C, by the sea.

On Sun, 21 Nov 2010 18:47:49 +0000, Justin C
wrote:

This is cutting edge stuff, most anecdotal rebuttals here have been
based on old ideas and technology. Here's a bit more about it:
http://www.matternetwork.com/2010/11...f-cruising.cfm

Several of us have done analyses based on the laws of physics, which
have yet to be repealed by new technology. Water mills are well
understood, have been around for a long time, and do not require the
application of quantum mechanics. A 20 inch prop being dragged
through water at 6 knots can generate somewhere between 1 and 4 KW of
electricity depending on how optimistic your assumptions are. Even
the high end number is not enough to recharge a *large* battery bank
in a reasonable length of time.

On Sun, 21 Nov 2010 18:49:10 +0000, Justin C
wrote:

In article , Joe wrote:
On Nov 20, 1:20?pm, Justin C wrote:
In article , Bruce wrote:
On Fri, 19 Nov 2010 23:34:40 +0000, Justin C
wrote:

quote
? ? ? ?The GREEN MOTION system eliminates fossil fuel used by sailing
yachts in any way. Electrical energy is generated with the system and is
stored in batteries (lithium Iron Phosphate are optional). It will
generate sufficient energy to be used for propulsion, hot water, cooking
and all electrical equipment and navigation on board. When batteries are
fully charged or high speed is required (race) the lifted Motogens
eliminate the drag from the propulsion system and this increases the
speed of the yacht (between 5 - 15%).

? ? ? ?Retractable Motogen
? ? ? ?The electric retractable Motogen is new, light
weight, extremely efficient and better than any propulsion system ever
designed for yachts. Usable in all sailing yachts from 30 to 90 ft (9-30
m): monohull, catamaran or trimaran). Installation can be made inside
the hull in a monohull or on a retractable arm for multihull. 5 years of
extensive testing has been done with a ?proof of concept? sailing in
excess of 10.000 Nm.
/quote

URL:http://www.green-motion.com/

I suspect that the estimates of ?drag versus speed for the generator
propeller is highly optimistic. The best estimates I can find are that
the drag from a 3 bladed prop reduces speed by about 15%, not the 5 -
15% mentioned.

They put a small amount of current through the motors as the same time
as using them to generate, this partially compensates for the drag -
according to last month's Yachting Monthly feature.

? ?Justin.

--
Justin C, by the sea.- Hide quoted text -

- Show quoted text -

I guess they could not afford a CVP prop to reduce drag when needed.

When not needed the motogens lift clear of the water entirely.

Justin.

Then, of course, they aren't making electricity :-)

Cheers,

Brice

On Sun, 21 Nov 2010 16:52:21 -0500, Wayne.B
wrote:

On Sun, 21 Nov 2010 18:47:49 +0000, Justin C
wrote:

This is cutting edge stuff, most anecdotal rebuttals here have been
based on old ideas and technology. Here's a bit more about it:
http://www.matternetwork.com/2010/11...f-cruising.cfm

Several of us have done analyses based on the laws of physics, which
have yet to be repealed by new technology. Water mills are well
understood, have been around for a long time, and do not require the
application of quantum mechanics. A 20 inch prop being dragged
through water at 6 knots can generate somewhere between 1 and 4 KW of
electricity depending on how optimistic your assumptions are. Even
the high end number is not enough to recharge a *large* battery bank
in a reasonable length of time.

The whole thing is basically ludicrous.

Boats have been essentially "green" for centuries, in fact I once
owned a Friendship Sloop that was. No motor, no electric lights, no
navigation gear other then a compass. I sailed up and down on the
coast of Maine with no real problems. Has a little one burner kerosene
stove for cooking and woolen clothes for heating.

The Bugis sailed their schooners around the Java Sea until relatively
recently with no motor, air con, ice makers or fridges, and smaller
boats still do in that area.

I agree that these boats weren't completely green as they used
kerosene for nav lights and cooking but likely less energy then is
taken to make the batteries and motors that power that Million Dollar
Cat that Justen mentioned.

The real question is not how to build a yacht that uses no energy but
how to find a yachtsmen that doesn't demand all those luxuries.

The Pardies have sailed for years with no electricity except for
batteries and no motor and while I dislike Lynn's writing you can't
deny that they have made some impressive voyages - all relatively
green; probably if one includes the energy needed to manufacture all
the various bits needed to build a Green Boat, a far greener boat then
others.

What we need isn't green boats, it is green people.

Cheers,

Brice

One of the problems using the engine propeller to turn an alternator
is that the prop pitch is all wrong.

By 90 degrees, in fact.

Bruce wrote:
On Sun, 21 Nov 2010 16:52:21 -0500, Wayne.B
wrote:

On Sun, 21 Nov 2010 18:47:49 +0000, Justin C
wrote:

This is cutting edge stuff, most anecdotal rebuttals here have been
based on old ideas and technology. Here's a bit more about it:
http://www.matternetwork.com/2010/11...f-cruising.cfm
Several of us have done analyses based on the laws of physics, which
have yet to be repealed by new technology. Water mills are well
understood, have been around for a long time, and do not require the
application of quantum mechanics. A 20 inch prop being dragged
through water at 6 knots can generate somewhere between 1 and 4 KW of
electricity depending on how optimistic your assumptions are. Even
the high end number is not enough to recharge a *large* battery bank
in a reasonable length of time.

The whole thing is basically ludicrous.

Boats have been essentially "green" for centuries, in fact I once
owned a Friendship Sloop that was. No motor, no electric lights, no
navigation gear other then a compass. I sailed up and down on the
coast of Maine with no real problems. Has a little one burner kerosene
stove for cooking and woolen clothes for heating.

The Bugis sailed their schooners around the Java Sea until relatively
recently with no motor, air con, ice makers or fridges, and smaller
boats still do in that area.

I agree that these boats weren't completely green as they used
kerosene for nav lights and cooking but likely less energy then is
taken to make the batteries and motors that power that Million Dollar
Cat that Justen mentioned.

The real question is not how to build a yacht that uses no energy but
how to find a yachtsmen that doesn't demand all those luxuries.

The Pardies have sailed for years with no electricity except for
batteries and no motor and while I dislike Lynn's writing you can't
deny that they have made some impressive voyages - all relatively
green; probably if one includes the energy needed to manufacture all
the various bits needed to build a Green Boat, a far greener boat then
others.

What we need isn't green boats, it is green people.

Cheers,

Brice



Bingo!


--

Richard Lamb
email me:
web site: www.home.earthlink.net/~cavelamb

On Sun, 21 Nov 2010 22:49:30 -0600, CaveLamb
wrote:

One of the problems using the engine propeller to turn an alternator
is that the prop pitch is all wrong.

By 90 degrees, in fact.


It works though, witness the bloke I mentioned that had an alternator
belted to the propshaft.... just that it doesn't produce much power.

Cheers,

Brice

On Nov 22, 5:10*am, Bruce wrote:
On Sun, 21 Nov 2010 22:49:30 -0600, CaveLamb
wrote:

One of the problems using the engine propeller to turn an alternator
is that the prop pitch is all wrong.

By 90 degrees, in fact.

It works though, witness the bloke I mentioned that had an alternator
belted to the propshaft.... just that it doesn't produce much power.

Cheers,

Brice

Why not use stone wheels too Bruce, since you are talking about stone
age tech? Using a belt drive and a big alternator is not going to
capture much energy anything.

Now directly couple a motor/generator that consists of a stator
winding employing a high pole count configuration, which allows for
high copper utilization (minimizing energy loss and cost), and a
hollow rotor upon which powerful rare earth permanent magnets are
mounted on the outer circumference coupled to a variable pitch prop
system and you can pump out some serious energy. The city buses that
are using these moters claim they capture 97% of the kinetic energy
developed while stopping.

You are comparing apples to oranges.

Joe