This report was produced under the technical assistance project Promoting Renewable Energy, Clean Fuels, and Energy Efficiency in the Greater Mekong Subregion (TA 7679). It provides outlines of business models relevant to pursuing the renewable energy and energy efficiency targets adopted by the five Greater Mekong Subregion countries: Cambodia, the Lao People's Democratic Republic, Myanmar, Thailand, and Viet Nam. Business models for investments in renewable energy and energy efficiency provide policy makers and investors with alternative business methods for the deployment of new technologies, or for the application of well-established technologies and practices in new settings.