On Sat, 20 Nov 2010 21:18:30 -0500, Wayne.B
wrote:

It's definitely not perpetual motion but it does depend on a number of
assumptions that may not hold true in the real world. Extracting
energy from spinning props is definitely possible under the right
conditions but my calculations show that the maximum power available
is relatively low, quite possibly enough to supply house loads, but
very unlikely enough to recharge a large battery bank.

Wayne, you hit the nail on the head as they say.

As most of you know I spent about 6 years living on solar and wind
power, and built electric cars, trikes and motorcycles. So I'm all for
renewable energy and have put my money where my mouth is. But, and a
very big BUT, there are very severe limitations as to what it can do.

You just can't get vast amounts of power from wind, sun and water
unless you take up vast amounts of space and spend vast amounts of
money. One thing that comes to mind. Recently the town here dedicated
a Windspire wind generator at the library. The wind gen and everything
else was donated by various companies in town. It's a 30 foot high
thing that maxes at 1,200 Watts. Of course, like most that figure is
with a 65 MPH wind. More like 100 Watts at the normal 15 MPH winds
here. Anyway, they stated that it should save the libray about $200 a
year in electric costs. Their normal electric bill is about $5,000 a
year!

I just had a thought that might illustrate the problem, at least as
far as propulsion goes. Instead of looking at Amps or Watts directly,
lets look at Horsepower.

1 HP is 746 Watts. Now, to charge a battery there are losses, and to
get that 1 HP there are also motor losses. So to make it easy let's
say 1 HP out is 1,000 Watts, or 1 KW, in. That's 74.6% efficientcy.

Let's further say 10 HP is what we need to power the boat at a decent
speed. In the real world, probably 5 KTs for a 30 footer. Our 30
footer with 10 HP motor has 16 golf cart batteries in series for 96
Volts and 21.6 KWH. This will give us 2 hours and 10 minutes of run
time to a flat battery bank.

Most of what I've read about using an alternator on the prop state the
output is about 10 Amps, so at 13.6 Volts this is 136 Watt Hours, or
..136 KWH. Traveling 10 hours a day gives us 1.36 KWH per day. So a 10
hour sail would let us motor for 8 minutes and 10 seconds.

One could hang a big prop down there, optimised to drive an alternator
and maybe get 50 Amps with a large reduction in speed. That would give
us about 40 minutes run time.

How about solar? If we cover that entire 30 footer in solar panels, we
should be able to get about 3,000 watts. At a cost of $15,000 plus
controller at the current $5 per watt. This will give us between 9 KWH
and 18 KWH per day, depending on latitude and season.

Sooo... We can run under power from 54 mintes to 1 hour and 48 minutes
per sunny day.

We all know air conditioners are power hogs. A 15,000 BTU marine AC
takes about 1.5 HP. So imagine generating enough power to run 6-1/2 of
your AC's. That what you need to power a 30 footer.

Rick

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.

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

On Mon, 22 Nov 2010 07:21:00 -0800 (PST), Joe
wrote:

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.

Regardless of the capture mechanism, even at 100% efficiency, there is
only so much energy in a moving column of water and it is not a big
number when you are moving at sailing speeds. Now if you could get
that same column of water rolling down the side of a 1,000 ft
mountain, that's a whole different story. :-)

On Nov 22, 9:40*am, Wayne.B wrote:
On Mon, 22 Nov 2010 07:21:00 -0800 (PST), Joe

wrote:
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.

Regardless of the capture mechanism, even at 100% efficiency, there is
only so much energy in a moving column of water and it is not a big
number when you are moving at sailing speeds. *Now if you could get
that same column of water rolling down the side of a 1,000 ft
mountain, that's a whole different story. * :-)

I'm going to have to disagree with you Wayne. The amount of energy
coming off a shaft at sailing speed can be huge. The drag can be
offset by canvas with ease on a non-planing hull. If you capture 1 rpm
of energy for every 4 rmp's generated by sail, and can store that
energy you have a system that can work.

Now if a bus can capture 97% of the kinetic energy by stopping then
why can't a prop do the same ?
About the smallest CVP system available is in the high 30's low 40"
diameter.
You ever chain down a shaft to a 40" prop? You better have some strong
chain.

http://www.youtube.com/watch?v=6KSnH6DFA94 Not quite a 1000 ft drop
but plenty of power to harness.

Joe

On Nov 22, 10:54*am, Joe wrote:
On Nov 22, 9:40*am, Wayne.B wrote:





On Mon, 22 Nov 2010 07:21:00 -0800 (PST), Joe

wrote:
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.

Regardless of the capture mechanism, even at 100% efficiency, there is
only so much energy in a moving column of water and it is not a big
number when you are moving at sailing speeds. *Now if you could get
that same column of water rolling down the side of a 1,000 ft
mountain, that's a whole different story. * :-)

* I'm going to have to disagree with you Wayne. The amount of energy
coming off a shaft at sailing speed can be huge. The drag can be
offset by canvas with ease on a non-planing hull. If you capture 1 rpm
of energy for every 4 rmp's generated by sail, and can store that
energy you have a system that can work.

*Now if a bus can capture 97% of the kinetic energy by stopping then
why can't a prop do the same ?
About the smallest CVP system available is in the high 30's low 40"
diameter.
You ever chain down a shaft to a 40" prop? You better have some strong
chain.

http://www.youtube.com/watch?v=6KSnH6DFA94*Not quite a 1000 ft drop
but plenty of power to harness.

http://www.youtube.com/watch?v=WBWqy...ist=QL&index=1

Even better view....I like the "Steel Rat" name.

Joe

Joe- Hide quoted text -

- Show quoted text -

On Mon, 22 Nov 2010 08:54:03 -0800 (PST), Joe
wrote:

On Nov 22, 9:40*am, Wayne.B wrote:
On Mon, 22 Nov 2010 07:21:00 -0800 (PST), Joe

wrote:
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.

Regardless of the capture mechanism, even at 100% efficiency, there is
only so much energy in a moving column of water and it is not a big
number when you are moving at sailing speeds. *Now if you could get
that same column of water rolling down the side of a 1,000 ft
mountain, that's a whole different story. * :-)

I'm going to have to disagree with you Wayne. The amount of energy
coming off a shaft at sailing speed can be huge. The drag can be
offset by canvas with ease on a non-planing hull. If you capture 1 rpm
of energy for every 4 rmp's generated by sail, and can store that
energy you have a system that can work.

Now if a bus can capture 97% of the kinetic energy by stopping then
why can't a prop do the same ?
About the smallest CVP system available is in the high 30's low 40"
diameter.
You ever chain down a shaft to a 40" prop? You better have some strong
chain.

http://www.youtube.com/watch?v=6KSnH6DFA94 Not quite a 1000 ft drop
but plenty of power to harness.

Joe

Are you normally obtuse, or have you always gotten your technical
information from the movies?

The Youtube show you recommended states that it is a 200 ton sailing
boat. While your reference doesn't indicate the length of the vessel
but seems to say that they were doing 9 knots.

I found a reference to another 200 ton sailing vessel on the net - it
was 138 feet long. The hull speed for a 138 ft. vessel is about 16
knots so your reference was sailing at abut half hull speed (56%
actually). Hardly impressive.

And, by the bay, how many sailing yachts have you been on that were
fitted with a 40 inch propeller?

Cheers,

Brice

On Mon, 22 Nov 2010 07:21:00 -0800 (PST), Joe
wrote:

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

How does, as you say "high copper content" decrease costs?

Cheers,

Brice

On Nov 22, 6:19*pm, Bruce wrote:
On Mon, 22 Nov 2010 07:21:00 -0800 (PST), Joe





wrote:
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

How does, as you say "high copper content" decrease costs?

Cheers,

Brice- Hide quoted text -

- Show quoted text -

According to UQM" The stator is affixed to an aluminum housing, which
contains mounting end bells and bearings. This allows the rotor to be
suspended within the stator. Commutation of the machine is
accomplished electronically by sensing the position of the rotor in
relation to the stator, and intelligently pulsing electrical energy
into the stator such that the electric field generated by the stator
interacts with the magnetic field of the rotor producing rotational
motion (“motor operation”). Conversely, the application of rotational
motion to the rotor by an external force results in the generation of
electrical power (“generator operation”). UQM® machines can be
operated in either a forward or reverse direction of rotation and
either in motor or generator mode and can dynamically change from one
mode of operation to another in millisecond response time. The hollow
design of the rotor permits the packaging of other components such as
gears and electromechanical brakes in the interior of the machine.
These design features contribute to lower usage of copper and iron and
other materials generally (due to smaller package dimensions),
reducing manufacturing cost over those for conventional machines of
similar power. In addition, the utilization of neodymium-iron-boron
(“NdFeB”) magnet material in a wide range of consumer devices, such as
cell phones, disk drives and medical devices, has dramatically
improved the availability, performance and price of this material,
allowing us to price our advanced motors and controls competitively
with lesser performing conventional motors which we believe will
accelerate the rate of commercialization of our technology."

Joe