This chapter focuses on the operation and control of off-grid systems. Operation and control at the AC bus is emphasized. A power flow model is developed that allows the power output and input from each generation source, energy storage, converter, and load to be computed. Methods for synchronizing and regulating AC bus frequency and voltage with inverters and gen sets are described. Load sharing approaches such as droop, isochronous, Controller–Responder, and frequency shift power control are presented. The concept of priority schemes and gen set control schemes such as load following and cycle charging are introduced. The chapter concludes with a discussion of remote monitoring and control for off-grid systems.