Genset for top drive unit

A system comprising:

• a motor unit including a control swivel;
• an accessory tool releasably connected to the motor unit and selected from a group consisting of a casing unit, a cementing unit, and a drilling unit, wherein the accessary tool includes one or more hydraulic passages, and the one or more hydraulic passages are connected to the control swivel when the accessory tool is connected to the motor unit;
• and
• a genset mounted to the accessory tool and comprising:
• a fluid driven motor having an inlet and an outlet for connection to the control swivel via the one or more hydraulic passages in the accessory tool;
• an electric generator connected to the fluid driven motor;
• a manifold having an inlet for connection to the control swivel and an outlet connected an accessory tool actuator;
• and
• a control unit in communication with the electric generator and the manifold and comprising a wireless data link.