An artist's impression of what a Flying Electric Generator might look like

Taking the form of a giant H-shaped frame, the prototype FEG has four huge blades at the four points of the H, each blade 10.7 meters (35 feet) in diameter. These act like the rotors of a helicopter, lifting the FEG to the required height.

Once in place, the blades not only keep the FEG air-born, providing lift like the surface area of a kite, but also act as turbines, turning dynamos within the platform that generate electricity, which is transmitted back to earth through a vast aluminum tethering cable.

An in-built GPS (Global Positioning System) uses satellite technology to ensure that the FEG always remains in the same place, both vertically and horizontally.

According to Shepard, development is already at an advanced stage.