A staff member walks past a data screen at a new energy and big data branch of the State Grid Qinghai Electric Power Company in Xining, northwest China's Qinghai Province, June 20, 2018. Northwest China's Qinghai Province on Wednesday initiated a nine-day clean energy power supply project following a successful seven-day trial last year. The province plans to only use green energy sources to generate electricity from June 20 to 28 to promote the use of clean energy. (Xinhua/Zhang Hongxiang)

Author： 　　　Source：xinhua　　　 Editor：Yang Fan