This chapter is about the response analysis of a hybrid genetic firefly algorithm optimized Proportional Integral Derivative (PID) for frequency regulation in a two-area hybrid power system. The hybrid power system includes thermal, gas, hydro, and a microgrid. The microgrid consists of a Wind generator (WG), aqua Electrolyser (AE), and Diesel Energy Generator (DEG) with energy storage systems of a Fuel cell (FC) and Batter energy storage system (BESS). A frequency regulation scheme is much needed for all power systems during unexpected loading situations, during that time system stability is disturbed in terms of frequency difference and tie-line power deviation from the standard limit. To maintain the stability of the proposed system, a hybrid genetic firefly algorithm optimized PID controller is suggested in this chapter. The dominance of the hybrid genetic firefly algorithm tuned PI-PD controller is identified by equating the simulation result with GA & FA–PID controller performance in the same power system. In conclusion, the proposed controller has improved performance over other compared results, in terms of fast settling time and minimal peak values.