The development of renewable sources for electrical energy has become a mainstream focus in the field of electrical engineering. This book can be used by both engineers and researchers working to develop new electrical systems and investigate existing ones. Additionally, it can serve as a guide for undergraduate and graduate students during their study of electrical fields. The electrical devices that are used in renewable sources have complicated inner structures, and methods of computer simulation make the development of these systems easier and faster. Simulink, and its toolbox SimPowerSystems, is the most popular means for simulation of electrical systems. The topic of wind-generator (WG) systems simulation merits detailed consideration; therefore, this text covers an in-depth exploration of the simulation of WG systems, systems with batteries, photovoltaic systems, fuel elements, microturbines, and hydroelectric systems.