摘要:Generating electricity using Renewable Energy Sources (RES) is taking over more and more shares in the global market of energy production. This results from global energy policy which is closely related to the reduction of greenhouse gas emission and environmental pollution as well as to reducing consumption of fossil fuels. The constantly increasing number of producers of electricity from RES, such as Hydroelectric Power Plants and Small Hydroelectric Power Plants, gives an impulse for carrying out work on the development and improvement of their operation. It forces continuous work on development of technical diagnostics methods which allow to detect faults at an early stage and even, using properly designed systems, to prevent them or minimize their effects. The main task of the diagnostics and control systems is to identify any symptoms of inaccurate device operation. Next, to modify the algorithm so that the device is introduced to the area of correct operation. Detecting a defect at its initial phase gives opportunities to plan and prepare for the repair of the device. Using appropriate diagnostic methods helps to minimize the costs of major repairs and overhauls of machines and maintain the work efficiency at the desired level. This article presents selected diagnostic methods used in Hydropower Plants.