A technician monitors a screen in an energy station designed for the central business district is seen in this photo taken on Aug. 14, 2017 in Chongqing of southwest China. The energy station, supporting a cooling and heating system using the water from the surrounding rivers, provides a stable and efficient air conditioning for the skyscrapers in the district. The system is proved noise free, zero heat emission and no pollution after two months' trial operation. (Xinhua/Liu Chan)
