Earlier posts extolled cheap & reliable rigging methods based on steel ropeways suspended from terrain to "fly" pioneering AWECS. Harry Valentine presented a concept of a "sideways laddermill" suspended across a valley. Wayne German, independently envisioned vast crosswind AWE like "vertical blinds."
This post adds detail from Aerial Lift Technology as used in mining, logging, crane operations, modern ski-lifts, & tourist tramways. As glamorous or technical as some examples seem, the principles are simple. A pulley clothesline with clothespins is a basic detachable aerial payload ropeway system. To generate power just backdrive the system by wind acting on the "laundry".
Prototype AWECS are easily testable on existing tourist ropeways. Multiline systems create highly stable control points in mid-air & keep gallop in bounds. Funitel & 3S system experience suggests that AWECS can safely hang in howling wind too strong for passenger comfort. The largest tramway gondolas easily carry 200 seated passengers suggestive that single AWECS elements rated to about 10mw are possible. A compelling flygen demo is as easy as hanging a small COTS HAWT from a detachable chairlift & winding it out to a spectacular spot.
Modern hybrid ropeway systems mix conveyances like detachable gondolas & chairs. By such methods diverse AWECS modules can reeled out like laundry into strong clean wind. Hotswappable generators, gearboxes, & turbines allow tailoring a turbine mix to seasonal or daily forecast conditions. Flygens connected to nearby transmission lines already at mountain altitude have a considerable advantage over those that must carry all their conductor aloft. Sweeping tethered foils mounted with flygen turbines can go nuts without special automation. High altitude AWE can be flown off of ropeways incorporated primarily to avoid launching and landing headaches.
KiteLab Ilwaco designs & builds diverse AWECS harvester modules for testing. Many concepts develop useful power, but require comparative evaluation to decide best practice. Combined kite & ropeway tech provide a robust engineering language. Prototypes tested in parallel by kite-lifter arches are now also tested on model "ropeways" hung from tall trees. Many options are attractive. Gondola "flygen" turbines use a drive shaft to stand-off a support cable while stabilizing & balancing the turbine. Such turbines hung from cable freely orient to wind direction, including rising & falling currents. Standard sailboat sails can be rigged ladder-mill style along a 3S cableway, with passive self-tacking cycles, for a high COTS AWE option.
Terrain is a grand tool for airborne windpower research. Mountains thrust up into superior wind, but also create turbulence & shadows that ropeways can avoid. Isolated peaks with radiating ropeways can select favored wind directions. Gap wind occurs where a mountain ridge dams across prevailing wind with a gap allowing enhanced wind to blow thru. Narrowing valleys aligned with prevailing winds also boost wind. Many follow a daily "breathing" oscillation when driven by sea & land breeze, or a longer cycle driven by passing weather systems. Where prevailing winds dominate, valley and gap winds can be pretty much unidirectional.
Valley winds are accelerated jets with highly laminar-flow cores that only blow along a valley, not cross-valley. Such a feature can drive design in interesting ways, for example, a side box-canyon might be an ideal wind shadow for handling wings at ropeway WP terminal stations (a cavernous Terminal Shed of sheet metal can also create wind-shadow). The world's best gap & valley wind sites are an untapped terawatt scale resource where AWE methods can incubate in energy densities resembling high altitude wind.
In cableway rigging a Skyline is a single top track line along which loads move by gravity or haul lines. A Track Line is fixed cable along which trolleys roll. A Haul Line is moving cable used to pull loads along a track line. A super simple ropeway uses gravity to let elements out. A single Haul Line suffices to pull them back. Similarly, a halyard can pull an element up and gravity return it. For level runs a Haul-Back Line is added.
Sailors call it "line", some riggers insist on "rope", & engineers tend to refer to "cable", but the terms are tolerably interchangeable. An excellent introduction is gondolaproject.com
Retractable power conductors along cables (electrical & fluidic) are handled as Festooned Cable, moving cable hung from trolleys on a track rope that stows compactly at a fixed end & can be extended over long distances along a track cable.
FairIP/CoopIP ~Dave Santos June 25,2010 M1702
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