The Southeast Asia region will see rapid economic growth in the coming decades and energy use is set to grow significantly. Today, the region stands at a crossroads. On the one hand, it can pursue a path of continued reliance on fossil fuels, most of which come from non-indigenous sources, increasing the region’s emissions and exposure to volatile and increasingly expensive global commodity markets. On the other, the region could utilise its ample, affordable, indigenous renewable energy resources to lower energy costs, reduce emissions and drive regional economic development. This second edition of the ASEAN Renewable Energy Outlook was developed in collaboration with the ASEAN Center for Energy (ACE) and the ASEAN Secretariat’s Renewable Energy Sub-sector Network. It is guided by IRENA’s World Energy Transitions Outlook and details a comprehensive pathway for the development of a sustainable and cleaner regional energy system. It explores the role of end-use sector electrification, expansion of renewable generation, energy efficiency solutions, emerging technologies such as electric vehicles, hydrogen and battery storage-systems, as well the importance of expanding regional power sector integration.