This lecture discusses the limitations of using markets as energy allocation mechanisms, focusing on challenges such as decarbonization, investor return, and universal access. It explores the inefficiencies of market economies and the need for strong interventions like high CO2 taxes. The lecture also delves into the characteristics of markets, market failures, and the difficulty of limiting free markets. It emphasizes the importance of identifying and addressing the top challenges in managing energy to ensure a sustainable and efficient energy system.