In the last few years, following the increased sensitivity of public opinion and public administrations to clean energy issues, the use of renewable energy sources has strongly increased. Among these, wave motion energy is still not widespread with respect to solar and wind sources, yet there are many active studies focused on the development of the technology. The aim of this work is to analyze the operation of the ISWEC device, which exploits the gyroscopic effect of flywheels enclosed within a hull in order to generate electric power. The heart of the device is the Power Take-Off system (PTO), which converts the mechanical energy produced by wave motion into electrical energy.