The disclosure is directed to an apparatus or a system for generating energy in response to a vehicle wheel rotation. The apparatus or the system may include a roller configured to be positioned in substantial physical contact within a groove of a wheel of the vehicle. The roller may be configured to rotate in response to a rotation of the wheel. The apparatus or the system may further include a flexible arm rotatably couplable to the roller such that rotation of the roller causes the flexible arm to rotate. The flexible arm may be configured to exert a downward force on the roller to increase the friction between the roller and the groove of the wheel. The apparatus or the system may further include a first generator operably coupled to the flexible arm and configured to generate an electrical output based on the rotation of the flexible arm shaft and convey the electrical output to an energy storage device or vehicle motor.