This timely book examines the significant challenges and possible solutions for enabling efficient modernization of electric power systems. It addresses rapidly changing electricity infrastructure needs and technical requirements and provides a practical introduction to the past, present, and future of energy efficiency and power quality concepts. The book also looks at recent developments in custom power conditioners that help improve the performance of transmission and distribution systems, ensure reliability, and reduce costs. Modernization of Electric Power Systems is a valuable resource for practicing engineers, students, and researchers interested in exploring and implementing energy efficiency and power quality in modern energy systems with renewables.