A worker patrols at a converter station of ultra-high voltage transmission line from Qinghai to Henan, in northwest China's Qinghai Province, April 16, 2021. The clean power transmission volume of ultra-high voltage link between Qinghai and Henan has hit 10 billion kilowatt-hours (kWh), according to State Grid Corporation of China (SGCC). The 800-kilovolt direct current transmission line, stretching 1563 kilometers via four provinces, from northwest China's Qinghai, Gansu and Shaanxi provinces to central China's Henan Province, started its operation on December 30, 2020. The transmission line can transmit a total of 40 billion kWh annually at full capacity. (Xinhua/Zhang Hongxiang)