The 10 members of the Association of Southeast Asian Nations (ASEAN) are--along with China and India--shifting the centre of gravity of the global energy system to Asia. Southeast Asia is an extremely diverse set of countries with vast differences in the scale and patterns of energy use and energy resource endowments. Since 1990, the region's energy demand has expanded two-and-a-half times. The fundamentals suggest that considerable further growth in demand can be expected, especially considering that per-capita energy use of its 600 million inhabitants is still very low, at just half of the global average. This special report, in the World Energy Outlook series, assesses the prospects for southeast Asia's energy future as well as the implications for regional and global energy markets and policymaking.