This article assesses the significance of renewable energy technologies in the integration of the Northeast Asian energy sector. First, it provides a country-level analysis of renewable energy trends in China, Korea, and Japan. Then, it analyzes how domestic trends are linked from a regional perspective, highlighting opportunities and challenges posed by renewable energy technologies. Finally, it assesses the current state of affairs in energy cooperation and provides an appraisal of future developments, with particular attention to the issue of grid connectivity.