Advocates of circular-track AWES include NTS GmbH and KiteGen SrL (Carousel II). Who has priority to the ring idea is unclear, since its somewhat obvious and has been known for decades in the context of sail-carts on tracks. Makani claims somewhere to have vetted the AWES circle-track idea as too high capital-cost-to-power for the sparsely occupied vertical and side-load rated track. Worse still, the inherent difficulties of reliably controlling a fleet of close-spaced kite cars is daunting. Critical single-point failures, like tangles with neighbors and lines-down-on-the-tracks, will bedevil early operations.
 

These flaws disappear if the circular track is used to anchor a vast integrated kite arch/dome. Many more generator cars can be crowded on the track and pulled to-and-fro locally (antinodes) in semi-passive metachronic phasing, to match grid loads smoothly. There are endless variations possible to drive the generator cars on a circular-track by an integrated kite array. Extra anchor cars (nodes) add anchoring power to enable exploiting the full load rating of the whole track. The entire kite structure could be raised and lowered fully within the track circle to virtually eliminate the risk of tangles and other fouling events. The entire crosslinked array would rotate as one to match wind direction. Car motoring is available as needed.

This is just the fancier version of Mothra tech's dirt-cheap "circle-belay" method. As calculated geometrically, such dense arrays can make 100x greater intensive use of the land/airspace resource is possible---compared to sparse arrays of small single kites.