Power electronics, renewable energy systems, solar photovoltaics, wind energy, hybrid renewable systems, wide-bandgap semiconductors, smart grids, energy conversion, grid stability, sustainable energy. The integration of power electronics into renewable energy systems has emerged as a critical enabler of efficient energy conversion, grid stability, and sustainable energy solutions. This book chapter explores the fundamentals of power electronics, focusing on devices, energy conversion, and control technologies. It delves into their applications in solar photovoltaic systems, wind energy systems, and hybrid renewable setups, addressing technical, economic, and environmental challenges such as grid compatibility, cost, and sustainability. Innovations, including wide-bandgap semiconductors, smart control strategies, and integration with smart grids, are highlighted to showcase advancements driving renewable energy integration. Case studies in solar farms, offshore wind projects, and hybrid systems emphasize practical applications and lessons learned. The book chapter concludes with an analysis of future trends, emphasizing the role of power electronics in decentralized energy systems and the necessity of supportive policies to ensure widespread adoption. This study underscores the transformative impact of power electronics on renewable energy infrastructure, fostering a sustainable energy future.