I find it slightly weird that the thing can harness the wind both for keeping the height, carrying electric cables, flying forward and in addition turn the turbines and create energy. Jjust from the look of it, I would assume the turbines to generate too much air resistance and weight, causing the whole thing to stall and fall down. I think other designs are based on the mechanical energy being converted to electricity on the ground. But what do I know - I suppose the engineers have done their calculations.