China’s strong economic growth over the past 40 years has been followed by similar strong growth in energy consumption, based on coal. A continuation of this development is not sustainable, and China has set new ambitious targets for future energy systems development, which in reality calls for a genuine energy revolution in order to build a clean, low-carbon, safe, and efficient energy system towards 2035 and 2050. This paper looks at the mechanisms behind the energy transition, analysis of a concrete case for a sustainable energy system in 2050, and points to policy measures and instruments to ensure the necessary progress in this energy transition. The case shows that it is possible for China in 2050 to reduce CO₂ emission to one-third of today’s emission while at the same time maintaining economic growth, improving security of supply, air quality, and economic efficiency of the power system.