The electric sector is one of the main emitters of greenhouse gases that lead to exacerbating global warming. There is a lack of consensus in the literature regarding renewable energy (RE) determinants and their impacts on the power sector. Using a panel fully modified OLS model, we examine the effect of research and development, the human development index, technological innovation, and other factors on the share of RE sources in electricity generation in six Association of Southeast Asian Nations (ASEAN) member countries from 2000 to 2018. We find that research and development, the human development index, and technological innovation have different effects on different RE sources. The human development index and research and development, for example, modify the composition of RE by shifting resources from conventional RE sources such as hydropower to newer, more technology-intensive ones such as solar, wind, and bioenergy sources. Our findings show that technological innovation, captured by a number of patent filings, has nonsignificant effects on RE sources deployment. Population growth and energy consumption increase the adoption of more advanced RE sources, and higher levels of CO2 emissions are associated with more deployment of solar and wind technologies but less adoption of hydropower and geothermal energy. Our results provide fresh insights for policymakers enacting RE policies worldwide, especially in the ASEAN region.