China has begun building the world’s first utility-scale power plant combining two emerging technologies: supercritical carbon dioxide (CO2) generation and large-scale molten salt energy storage. The Ruitan project, under construction at a coal-fired power station in Yantai in eastern China’s Shandong province, is intended to demonstrate how combining these technologies can reduce energy wastage and improve the stability of the electrical grid. Electricity produced when demand is low is stored...