Fundamentals of Power System Economics, Second Edition, authored by Daniel S. Kirschen, delves into the core economic principles essential for understanding and navigating competitive electricity markets. This updated edition reflects the evolving landscape of these markets, particularly with the integration of renewable energy sources. The book provides a comprehensive overview of microeconomic concepts, market organization, and operational strategies. It covers crucial topics such as market participant behavior, reliability, ancillary services, congestion management, transmission investment, and generation planning, all within the context of competitive environments. A significant addition in this edition is an expanded discussion on capacity mechanisms, addressing the challenges posed by intermittent renewable energy sources. Ideal for students, professionals, and policymakers in the field of power systems engineering and economics, this book offers a vital guide to successfully designing and operating modern power systems.