Hybrid power generation system using Offshore-wind turbine and Tidal turbine for Power fluctuation Compensation (HOT-PC) is an autonomous power system. Electric power is generated from both offshore wind and tidal and is distributed over the load system. Power quality problems such as frequency fluctuations and voltage sags, which arise due to a fault or a pulsed load, can cause interruptions of critical loads. This can be a serious concern for the survivability of the offshore-wind power system. In the proposed system HOT-PC, the induction generator for the tidal turbine can play also as a motor to store kinetic energy to mitigate (make stable) the frequency and voltage fluctuation. The tidal generator is controlled by six-pulse insulated gate bipolar transistor (IGBT) bidirectional converter system. When the generator/motor is driven by the converter to exceed the tidal turbine rotating speed, it is mechanically isolated from the turbine by a one-way clutch and can charge and discharge the kinetic energy like a fly-wheel. In order to study the feasibility of the system, the laboratory scale model was designed and made. This paper presents the fundamental configuration of the system, the experimental results, and discussions of basic operation performance of the proposed system.