Naval Service in historic kite sail tests

http://edge.rit.edu/content/P14462/public/Working%20Documents/Research/P14462%20-%20Lansdorp%20-%202005%20-%20Comparison%20of%20concepts%20for%20high-altitude%20wind%20energy%20generation%20with%20ground%20based%20generator.pdf

Figure 1 shows the Laddermill concept. As we know this concept has been studied and described in first by Douglas Selsam then by Wubbo Ockels. After,for Tu Delft, Laddermill became a generic word naming their whole searches in AWE. So the mention comprising [30 or 40 years...] probably refers to their general R&D in AWE rather than the system by itself.

Figure 2 shows Pumping mill (a train of kites reeling).

Figure 4 shows a " Laddermill with wings on ropes for cross wind power" . The mention (not on this paper) as SpiderMill seems refer to this figure 4.

PierreB

DougS,

Here http://www.lr.tudelft.nl/en/current/latest-news/article/detail/europese-subsidie-voor-kite-power/ is a link . A quotation :"Spiritual father
Kites have been used for centuries, for example in meteorology, but their use for the generation of energy is new. An early version of the technology was patented by Wubbo Ockels in 1998. That was the Laddermill (or Laddermolen in Dutch), that combined a number of wings on an endless line loop. “We have simplified this to a single wing on a line”, explains Schmehl. “Wubbo Ockels’ idea was beautiful as a concept, but probably 40 years ahead of its time. But you need visionaries like him to indicate a direction. Unfortunately, he did not experience the success of the ITN application, which would have been confirmation of his vision. In the early days, around 2000, he was one of only three researchers worldwide who were working on kite power. Now there are around fifty institutions, academic or industrial, that focus professionally on the new technology.”

These words "Ockels’ idea was beautiful as a concept, but probably 40 years ahead of its time. But you need visionaries like him to indicate a direction." refer to " ... but their use for the generation of energy is new" rather than to the Laddermill concept by itself.

PierreB

• Interview Wubbo Ockels

  			Interview Wubbo Ockels 'Mensen zijn gemaakt voor het aardse land' Wubbo Ockels over leven in de ruimte, op zee en over de hoge opbrengst van windenergie uit de laddermolen
  			View on www.ecoboot.nl	Preview by Yahoo

   

• Open call to wikis of any language.  Whenever "laddermill" or "ladder mill" is in focus as to "invention" then a firm note and reference to the work of Doug Selsam in the late 1970s for the concept would seem to be fair.  Ockels was simply not the first to express the mechanical foundations of loops of foils in fluid streams for purpose of mining energy captured by the loop of foils; the fundamental method was in the public domain at the time Ockels filed for a patent on the method.   Such history does not detract from Ockels leadership in bringing kite energy to academic circles; communication leadership is not identical to mechanical invention.  Any author that continues to neglect to examine the validity of mechanical invention over the loop-ladder method of mining energy from fluid flows will be contributing to a confusion of historical matters.
  
  

• Tree-branching of sub-kites and coteries and clusters of sub kites are century-old matters. Obvious AoA alterations of kited wings is old art. Mining wind's energy with such systems is easy obvious matter. Changes in the tension of the tether set of such complexes allow tasks to be done at the resistive set of the kite system.  The "spider" mill falls in such family of systems. Trains are simply part of this family of AWES.   Cause pulsation; mine the pulsing. Use pilot lifters as wanted; pulse them also, if wanted. Crowd wings effectively with smarts or passive ties for aggregate stability.  Have reeled systems or systems that do not winch.  Mount such complexes on arch lines or arch wings in some versions.

~ JoeF

Some correction: 44579 m3 (the double) as volume for the 3-bladed HAWT.

PierreB

I sent the same post to both "Google-Makani M600 Bridle Collision Risk" topic and "Makani-Google M600, land and space use" new topic. Indeed my post is in touch with M600 but is not in touch with bridle collision risk.

PierreB

DaveS,

One can add some wind gradient advantage for M600, but M600 cannot flight at very high altitude due to drag of moving tether. Generally a farm of M600 does not look economically viable (dangerous, no possibility of secondary land use, no maximisation of space...) , so waiting for a crash is not required; at the contrary a crash is able to waste the credibility of whole AWE. So R&R should go towards AWES having some possibilities to maximize space, to fly at really high altitude in spite of FAA limitations, to minimize hazards, to allow secondary land/sea use: Guangdong project has some possibilities to become economically viable, and also the idea of pilot kite as both lifter and separator is a possibility.

PierreB