This paper is part of the IEA ongoing analysis of global renewable energy markets and policies. It focuses on six Southeast Asian countries: Indonesia, Malaysia, the Philippines, Singapore, Thailand, and Vietnam. The report investigates the potentials and barriers for scaling up market penetration of renewable energy technologies in the electricity, heating and transport sectors in the six countries. In addition to analysing the implications of effective policies on renewable energy market growth, it examines how to overcome economic and non-economic barriers that slow investment in renewable energy, and offers policy recommendations to encourage effective and efficient exploitation of renewable energy in Southeast Asia.