X – Google parent company Alphabet's "moonshot” technology development arm – has completed the maiden flight of its 600kW high altitude wind energy (HAWE) kite, at a secret site in the California desert.

The device, which is built around an 85 foot wing featuring eight onboard rotors each 7.5 feet in diameter, generates power while following “cross-wind flight” patterns 300-1,200 feet in the air, with produced energy travelling down a tether to a ground-base below.