This document summarizes the dynamics of the electricity supply industry (ESI) in ASEAN countries. It discusses key challenges facing the ESI, including depleting energy resources, high demand growth, investment needs, and increasing fuel prices. It also examines strategies countries are taking to ensure energy supply security, such as fuel diversification, developing domestic resources like natural gas and hydroelectric power, and investing in infrastructure like LNG import facilities. Maintaining a balance between factors like supply security, costs, sustainability, and safety is important for utilities to meet responsibilities of delivering reliable electricity.