A belt wave drive transmission system and method are shown involving a first rotor (10) having a first drum configured to rotate about its axis of rotation and a second rotor (20) having a second drum configured to rotate about its axis of rotation, where the first rotor (10) is constrained to orbit concentrically about the axis of rotation of the second drum. A belt (30) encircles the first and second drums to couple the first (10) and second (20) rotors such that the first rotor (10) moves concentrically around the second rotor (20) as the belt (30) advances about a circumference of the second drum. In further refinements, the system and method involve electrically controllably coupling at least one of the first and second rotors to the belt.