OK, looking at Kitegen's multi stem idea, I see a version of a vertical axis wind turbine It has the usual problem of a vertical axis machine, which is, at any one time, half of the kites are moving into the wind and the forces on the ends of those stems result in torques which oppose the rotation of the base. Look at the first image in the linked graphic. What happens on the left side as the kite changes direction, which is actually outside the frame of the graphic? It would appear that the kite would need to make a fast climb to nearly vertical, then dive back down, a situation similar to "jibing" a sail boat, IMHO.

The graphic which shows a comparison of the intercepted area with that of a horizontal axis machine grossly overstates the effective area of the turbine and thus overstates the possible efficiency of energy conversion. The effective area should be the area of the kite(s). Also, the claim that only the tips of a horizontal axis turbine are efficient ignores the effects of both pitch control and proper twist along the blade.

Given the large size and slow rotational speed, it looks to be little more than a drag turbine. And, should the positioning mechanism fail on one kite, the whole thing would crash as the lines would become entangled after one revolution...

E. Swanson