Maker Pro
Maker Pro

Tree Wind Generator

  • Thread starter Dirk Bruere at NeoPax
  • Start date
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
An idea I've had for years, but never tried and never seen anyone else
do it either.
Simple idea - capture the energy of a tall tree swaying in the wind.
Rough numbers: 200kg force (2kN) through 0.3m every 2 seconds is
potentially around 330W.

Tie a line to the top of the tree to ground via a spring. Use the
movement of the tether to drive a ratchet connected to a generator.

Anyone know of anything similar?
 
T

Tim Williams

Jan 1, 1970
0
It would be pretty cool if you put the trees on a merry-go-round. Put up
some sort of wind screen so they only sway on the windward side. Instead of
200kg through 0.3m, you get maybe 100kg through 20m/s!

Moving/living sculpture projects aside, sway has the advantage of working in
place. Can't say I've heard of it before though.

Invent it, then market it to nut orchards -- turn the generator around and
it doubles as a tree shaker for harvest. :)

Tim
 
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
It would be pretty cool if you put the trees on a merry-go-round. Put up
some sort of wind screen so they only sway on the windward side. Instead of
200kg through 0.3m, you get maybe 100kg through 20m/s!

Moving/living sculpture projects aside, sway has the advantage of working in
place. Can't say I've heard of it before though.

Invent it, then market it to nut orchards -- turn the generator around and
it doubles as a tree shaker for harvest. :)

Tim

By attaching two lines at right angles it would not matter which way the
wind is blowing. All the material needed are pretty cheap on a per watt
basis (as well as absolute)
 
S

Sjouke Burry

Jan 1, 1970
0
Dirk said:
An idea I've had for years, but never tried and never seen anyone else
do it either.
Simple idea - capture the energy of a tall tree swaying in the wind.
Rough numbers: 200kg force (2kN) through 0.3m every 2 seconds is
potentially around 330W.

Tie a line to the top of the tree to ground via a spring. Use the
movement of the tether to drive a ratchet connected to a generator.

Anyone know of anything similar?
Wave generator, same principle.
 
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
I've heard of a micro power generator based on a paddle that waves back
and forth in eddies in a stream. The generator part is a magnet and
coil, similar to one of those shake flashlights.

No ratchet is needed. Just let the generator rotate back and forth,
producing AC. Then rectify it. Less moving parts, more reliable.

The question is how to turn massive force short stroke, low velocity
movement into energy efficiently. A simple magnet and coil would not
work well at all.
 
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
Trees only shake a lot in high winds. A wind generator needs to work
in light winds. There's a 'forest' of man made wind turbines that I
see every day driving home. I think that 90-95% of the time they are
spinning... I look at the tree's, sometimes I can't even see the if
leaves are blowing.

But a tree is a lot cheaper than a wind turbine on all counts.
It would be quite easy to make a portable unit for camping, or
recharging batteries off-grid. A cheap fill-in for PV.
 
P

Paul Keinanen

Jan 1, 1970
0
An idea I've had for years, but never tried and never seen anyone else
do it either.
Simple idea - capture the energy of a tall tree swaying in the wind.
Rough numbers: 200kg force (2kN) through 0.3m every 2 seconds is
potentially around 330W.

What kind of trees are you thinking about ?

I have wire antennas hanging from pine trees and if the movement and
forces would be as large as stated, the antennas would have snapped a
long time ago.
Tie a line to the top of the tree to ground via a spring. Use the
movement of the tether to drive a ratchet connected to a generator.

Anyone know of anything similar?

Possibly a usable system to power some flea power meteorological
station that transmits the cumulated data a few times a day.

For any real power production (e.g. summer cottage) this is
unfortunately a bad idea.

The kinetic energy of the wind is proportional to the third power of
wind speed and directly proportional to the cross section area and air
density. While there are quite stable winds above 600 m, the surface
roughness will drop the wind speed close to the ground.

On a small low island in the middle of a sea or a moderate tower in
the middle of a crass land will produce some usable power levels. In
areas with trees and bushes within a few kilometer, the wind turbine
would have to be well above the tree tops to produce usable levels of
power.

This tree spring idea was compared to wave power, however, the density
of water is about 800 times larger, so the extracted power density
would also vary in the same way.
 
P

Paul Keinanen

Jan 1, 1970
0
I've had long wire antennas in trees in New England for 50 years.
The wind motion WILL snap even strong wires, so there has to be
hundreds of pounds of force, at least some of the time.

The question is, how much sag do you accept in calm warm environment ?
With sufficient sag, the wire will not snap.

I have a multiband inverted-V dipole hanging from the tallest pine
tree with the ends of the element suspension wires suspended via other
pine tree branches "pulleys" into small trees acting as "springs".

Anyway, most of the dipole radiation is created close to the high
current point, i.e. close to the dipole feed-point, so the wire
sagging does not drop the radiated power in a significant way.
The typical "Solution" is to have one end supported by synthetic rope
going through a pulley attached near the top of the tree, and routed
down to the ground. A weight of 20 to 50 pounds (Typically a concrete
block or two) is attached to the lower end, keeping constant tension
on the antenna wire.

I've been out in a high wind, checking antennas, and seen those
weights move 2 or 3 FEET up and down. So the energy is there. I
never tried to USE it :)

Thus 10 .. 25 kg and 0.7 .. 1 m with unspecified cycle.

The original poster claimed
Simple idea - capture the energy of a tall tree swaying in the wind.
Rough numbers: 200kg force (2kN) through 0.3m every 2 seconds is
potentially around 330W.

Thus up to an order of magnitude less and then only during a storm.
How to capture and store it?? A ratchet / generator like those hand-
powered flashlights but bigger. (A rotary one-way clutch from an old
lawn mover, a drum and a rope?) Or pump water uphill and use it
later??

Lots of people will tell you you're crazy. But I have personally
adopted this quote from Buckminister Fuller (Inventor of the geodesic
dome) since I heard him say it at IBM many years ago:

"Dare to be Naive" ! !

Using trees swaying in the wind to produce a small amount of
electricity might be an interesting way of powering micro-power
electric gadgets and hence very much on topic in this news group.

Unfortunately, I have became quite allergic to some "green" claims
that if something works in a very specific environment, it will also
work for a whole family or solve the national or even global energy
needs :).
 
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
The question is, how much sag do you accept in calm warm environment ?
With sufficient sag, the wire will not snap.

I have a multiband inverted-V dipole hanging from the tallest pine
tree with the ends of the element suspension wires suspended via other
pine tree branches "pulleys" into small trees acting as "springs".

Anyway, most of the dipole radiation is created close to the high
current point, i.e. close to the dipole feed-point, so the wire
sagging does not drop the radiated power in a significant way.


Thus 10 .. 25 kg and 0.7 .. 1 m with unspecified cycle.

The original poster claimed


Thus up to an order of magnitude less and then only during a storm.

Just because the stroke is moving 25kg does not mean that it could not
move something 10x heavier.
After all, the above poster was adding weight merely to tension his lines.
 
P

Paul Keinanen

Jan 1, 1970
0
Just because the stroke is moving 25kg does not mean that it could not
move something 10x heavier.
After all, the above poster was adding weight merely to tension his lines.

Do you expect that the amplitude of the tree oscillation will remain
the same, when you put say, 250 kg hanging from the line ?
 
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
Do you expect that the amplitude of the tree oscillation will remain
the same, when you put say, 250 kg hanging from the line ?

No, I assume it will probably be in line with my example ie around 30cm
stroke in moderate wind. That's what I observe.
 
K

Kevin McMurtrie

Jan 1, 1970
0
Tim Williams said:
It would be pretty cool if you put the trees on a merry-go-round. Put up
some sort of wind screen so they only sway on the windward side. Instead of
200kg through 0.3m, you get maybe 100kg through 20m/s!

Moving/living sculpture projects aside, sway has the advantage of working in
place. Can't say I've heard of it before though.

Invent it, then market it to nut orchards -- turn the generator around and
it doubles as a tree shaker for harvest. :)

Tim

I've seen cylindrical turbines placed at the edges of buildings where
bad aerodynamics causes extreme winds. I found this for the turbines on
Park Ave. in San Jose, CA:

http://www.mercurynews.com/breaking-news/ci_14191622
 
Top