|Nice questions and concerns, Dave.
I hope others will come into the discussion. Maybe the 40 or so players
could reach phraseology that could be put up to a vote. But what will
happen one day when an investor or user finds out the historical fact that
they are investing in or using a kited tethered turbine system? Will we want
to be seen as ashamed of the raw engineering accuracy of our works?
Wayne German in his purity admonished the attendees as he proposed that the
public culture in this pioneering time could learn to use the word "kite" in
a proud and accurate manner; that goes against a thrust you put on the
table. Seeing the controlled OutLeader kite (even forget the
electric generator tertiary step) as a true airborne turbine stands as an
invitation, if such did not fit your seeing; such has minimal frequency of
oscillation, but it fulfills as machine the meaning of turbine.
At conference there was a huge amount of use of the word "kite" from
professor Milanese from Italy, from Ireland, from USA, from Germany.
Weighing for consensus brought out that every system was a system made
possible because of tethering to force a differentia that enabled kite
systems to convert the wind resource into mechanical energy. THEN the
mechanical energy was optionally used to do works--either works aloft or
works at ground. The third action after the mechanical energy was made was
variously sent to pump or make electricity either aloft or on ground. But in
all the systems the tug kite included, etc. the first action was to convert
the wind kinetic energy into mechanical energy; when done by means of an
oscillatory machine we have a turbine, even in the simple tug kite system.
Thus all the devices were tethered turbines very generically and accurately.
The low frequency of the simple tug kite, the yo-yo system kite is still in
macro a machine that extracts the stream's kinetic energy to result in a
useful mechanical energy to later be used for tertiary uses.
In brief, in engineering and practice, nearly every AWECS is a
tethered turbine, perhaps 100% of them, even your
KiteShip tugging working OutLeader system in equal status with
the airborne set of Selsam multi rotor
Superturbine Sky Serpent . The rotation rate may not be too exciting
in the slower oscillators (in the extreme: zero) when steady one-direction
simple tack is in place to give nearly zero-rotation on the tether for tug
and zero-oscillatory motion of the kite's sail part; but go to higher rates
of rotation in kite-control-unit for figure eights in
SkySails and we get a kite-sail body that rotates in its way to play
its part in capturing the kinetic energy of the stream of air for doing
work. The OutLeader tug kite system is a tethered turbine system, as it has
a low-frequency oscillation that converts wind kinetic energy to mechanical
energy...fundamentally because it is a tethered system permitting reach and
facing of higher differences (between the wind and the tugged mooring);
without the tethering the OutLeader would sink to the water; without the
tethering, the gained mechanical energy would not do the work of tugging.
Likewise, the auto-gyro kite of
SkyMill Energy is a tethered turbine.. They have the yo-yo method
going with generator on ground for converting the extracted kinetic energy
into mechanical energy and then into electricity by tertiary choice;
the wing and generator are coupled by tether; without the oscillating rotary
wing extracting energy from the kinetic energy of the wind, the system would
not have conversion choices (to heat, sound, electricity, light, potential
energy via pumping, installation of potential energy via new tensions,
etc.). They even described that at low wind they will oscillate the
kite body and the kite tether to get the relative wind increase advantage.
At end of power phase, that is, at the end of their using the system as a
tethered turbine, they will switch the generator to be a winching prime
mover to reel in a pitch-changed lower-resistive loft body in order to have
tether to release during a following power-phase.
The huge two-football-field sized Joby Energy powerable kite
(kites in part of its sessions and becomes a powered aircraft in part of its
flight session) is in two ways a tethered turbine: first in its macro
behavior without looking at the node turbines in its framed matrix of wings
and node turbines; then secondly the set of node turbines are tethered to
groundstation. Their rotation of the macro wing will be at zero when
wind is sufficient; they noted that they will control the macro tethered
wing to oscillate in special paths to increase crosswinding relative wind on
the node turbines. The Joby Energy scheme thus is a tethered turbine.
The Makani circle-pathing of its powerable kite (it too is proposed to
have choice of positively powering itself when needed to become a tethered
powered aircraft). The turbine blades mounted in the kite body are
horizontal-axis rotors relative to the relative wind during flight circle
figures. Such mining-of-energy phase for their craft is made possible by the
tether couple to groundstation. Thus, the Makani device is a tethered
Sky WindPower device holds the tertiary-choice of generators aloft.
First the device is a powered aircraft tethered to the groundstation as it
powers to altitude; then the power is turned off and attitude is adjusted so
that oscillation or rotary reaction from autorotation occurs in the
unpowered kited mode...busy extracting energy from the wind made possible by
the tethering of the kite body which holds autorotating blades. The
mechanical energy brought up from converting the kinetic energy of the wind
is by choice kept aloft to drive a set of electric generators, which
electricity is passed to either grid or storing loads at ground. Therefore,
the Sky WindPower system is a tethered turbine system.
Magenn Power rotatable LTA blimp is a rotating body extracting
mechanical energy from the stream; part of the extracted energy goes
mechanically aerodynamically into driving the macro rotation giving some
Magnus-effect lift; some of the derived mechanical energy is spent for
making heat, some for making sound, some for putting tension and stretch in
the tether; by tertiary choice they are setting up the device so that some
of derived mechanical energy drives end-plate "toroid" electric generators
for aloft production of electricity to be passed to loads at the ground.
Hence the Magenn device is a tethered turbine system.
Similar generic descriptor analysis applies to the tethered turbine
systems involved in the following companies:
Aeroix :: Project: EnerKite,
Baseload Energy, Advanced
Kite For Sail,
Kite Gen Research, KiteLab,
Sequoia Automation, SkyMill
Velocity Cubed Technologies, WindLift,
Aerostat by Potter . The various tethered kiteMotors of KiteLab are
likewise tethered turbines with tertiary choice to convert the mined
mechanical energy to drive pumping or electricity generation aloft or on
So far, only tethered turbine systems come to mind at the moment in the
emerging airborne wind energy industry. Indeed we also were gifted
with a demonstration by DaveS at conference with the fixture mounted
tethered turbine of the two bladed HAWT sort tethered from lifter kite which
invites Vestas to tether their turbine, but with the suggestion of leaving
the gearbox and electric generator on the ground while a lifter system
allows a replacement of the compression holding tower with a tether; the
mechanical energy could drive an endless loop to do pumping or electric
generation conversion at the ground for grid or potential energy storage,
say hydro head.
Tethering turbines in water streams is a going industry.
(using paravane tethered turbine),
proposes to adapt early patent schemes of generator in the
What are tethered turbines?
A turbine operating somewhere on a tether in a fluid is a tethered
turbine. Turbines positioned in fluid streams (water, air, molten glass,
methane gas, etc.) contrast with turbines positioned by non-tether frames.
To get clear, maybe we would have on the table a definition for
turbine and for tether.
A brief "turbine" offer is
"A turbine is an oscillatory machine that extracts energy from a fluid or
air flow and converts it into useful work."
A brief offer for "tether" is
"something (as a rope or chain) by which object-A is fastened to some other
object-B so that the objects can range under designed constraints."
I do not have your agreement yet on this platform, but I will continue
with those offers for now for "turbine" and "tether" in this first reply.
And it is on the table that frequencies can be zero to high.
The constraint of a ground-hugging non-cord compressive tower to hold a
wind turbine in its place as in the Vestas offers is ordinarily not
respected as tethering its turbine. Differently, the airborne devices that
are string (cord, rope, cable) tethered in the atmosphere or water streams
are seen commonly as tethered turbines, not hard-towered-held turbines.
AWECS are primarily kite systems (aerostatic kites and non-aerostatic
kites or combine hybrids that involve aerostats and kites, some macro
rotating and some whole-system rotating, albeit with some in oscillatory
line oscillation). The dominant action in AWECS is not gliding or powered
aircrafting, but interactions with the stream using kited complexes while
spending as little energy as possible to position the tethered turbine
systems for effective conversion of the kinetic wind energy to mechanical
energy. What one does with the mined mechanical energy is a tertiary
choice; where one places the tertiary conversion action is another decision
after the exercise of the tethered-turbine operation.
Finally, in the tethered turbine AWECS, there are very many kinds
of mounts for sub-elements that convert aloft the stream's kinetic energy.
Some blades are as beads set downwinding as nacelles can be low profile when
gearing and electric generators are not unwind but say on the ground. Some
windmill blades are kited themselves instead of giving full disk traverse to
the stream. When the kite body is hybridized so some cross winding mainsails
have in them sub-turbines and perhaps choiced electric generators, then
solid mounts or sub-tether downwinding torque flex-cables could be employed.
When a kite system is simple as in traction work with using the gained
mechanical energy immediately for tug (saving lots of coal and oil), then
the system is still a tethered turbine with low frequency oscillation during
the mechanical-energy mining.
I have been listening closely. What I hear (and read) in patents, at
conference, and in the kite energy literature is that AWECS are about
systems that are tethered turbine systems. Some are stretching
themselves to say they have an energy glider, a turbine in an aircraft,...
Some are doing giant gymnastics to avoid the mechanically accurate kiting
mode descriptor. If you have some phrases to offer, please begin
to use them in text. An investor who inescapably will be
informed by someone that the objects are kite system working as tethered
turbines will then have a more accurate connection with his or her
investment. If our emerging industry wants to forward phrases
and vote upon them, then some consensus might occur. If contortions go
too far from the deep literature and an investor is later hit with kite
...then a balking and negative reaction might occur. Kite system
is two words that neglects turbine; energy kite system is
three words and also neglects turbine, tethered turbines is two words but
faces the key work of mining energy from the stream while showing the
distinction that such is not a compressive towered fixture, but is remote at
length on a tether. I am all ears for options. The
related patent literature is full of turbine while in the body of the
patents is revealed that tether to the air above is essentially
involved. My ears and heart are open for phrases that our
industry may want. What have we?
Out there ...
Wind Energy with a Tethered Turbine" at a Science and
- tethered aerodyne
- tethered airfoil
- tethered airfoils
- tethered airfoil systems
- tethered airfoil technology
- tethered airfoil wind energy conversion system
1979 patent TAWECS
- tethered aviation
- tethered energy glider (kite that cycles into glide phase)
- tethered foil
- tethered hang glider
tethered horizontal axis wind turbines THAWT
- tethered tensile wings
tethered vertical axis wind turbines TVAWT
- tether position sensor
- tether scope (issue comes in with respect to land use of AWE)
- tether sensor
- tethered tension field wind turbine W. Roeseler "Billy"
|An old tethered turbine from the eighties, crushed in
storage, Shawn is mistaken about the difficulty of small cheap
reliable turbines. Blades are fom a beer can. Brooks saw many of
these fly in public. They made music & lit LEDs. No failures.
- tethered underwater current turbine energy generator
tethered wind turbine
- tethered wind systems
- tether frequency
- tether hook
- tethermares (nightmare situation with the tethers of a kite
system; awful challenge)
- tethister August 2009: "The latest "tethister"
tri-tether works well with trees. You simply anchor a line off from the
top of the tree a & tap the center of it to a spragged generator. A tree
is a dissipative aero/mass dampener array, not very efficient for
extracting power, so only small devices are really practical
think of a tetrahedron with its base on the ground; the sides of the
tetrahedron are tethers to a kited apex; in the central region of the
base is a working electric or pumping generator.