In this paper, genetically tuned fuzzy controlled super-capacitor energy storage system (SCESS) is employed to improve the frequency control of a hybrid wind-diesel system. Super-capacitor is interfaced with the system through voltage source converter and bidirectional DC-DC buck-boost converter. The fuzzy logic controller for SCESS is designed in such a way that the effect of load disturbance is continuously mitigated while considering the operational constraints of SCESS. The membership functions of fuzzy controller are tuned by employing genetic algorithm (GA) for optimal performance. Optimised membership functions are reached out by introducing a regulated variable based on supercapacitor voltage and frequency deviation of the system. To validate the proposed scheme, detailed model is developed and tested in MATLAB/Simulink environment.