Aerial photo taken on Dec. 26, 2021 shows a transformer substation of the ultra-high voltage transmission line of Nanchang-Changsha in Jinxian County, east China's Jiangxi Province. The 1000-kilovolt transmission line was officially put into operation on Sunday. (Photo by Xi Yutong/Xinhua)

Technicians inspect a transformer substation of the ultra-high voltage transmission line of Nanchang-Changsha in Jinxian County, east China's Jiangxi Province, Dec. 21, 2021. The 1000-kilovolt transmission line was officially put into operation on Sunday. (Xinhua/Zhou Mi)

Technicians work at the Ganjiang section of the ultra-high voltage transmission line of Nanchang-Changsha, east China's Jiangxi Province, Nov. 24, 2021. The 1000-kilovolt transmission line was officially put into operation on Sunday. (Photo by Hong Zibo/Xinhua)

Photo taken on Dec. 26, 2021 shows Xiaoxiang station of the ultra-high voltage transmission line of Nanchang-Changsha in Changsha County of Changsha City, central China's Hunan Province. The 1000-kilovolt transmission line was officially put into operation on Sunday. (Xinhua/Chen Zeguo)

A staff worker works at Xiaoxiang station of the ultra-high voltage transmission line of Nanchang-Changsha in Changsha County of Changsha City, central China's Hunan Province, Dec. 26, 2021. The 1000-kilovolt transmission line was officially put into operation on Sunday. (Xinhua/Chen Zeguo)

Staff workers monitor the screen at a transformer substation of the ultra-high voltage transmission line of Nanchang-Changsha in Jinxian County, east China's Jiangxi Province, Dec. 21, 2021. The 1000-kilovolt transmission line was officially put into operation on Sunday. (Xinhua/Zhou Mi)

Photo taken on Dec. 26, 2021 shows Xiaoxiang station of the ultra-high voltage transmission line of Nanchang-Changsha in Changsha County of Changsha City, central China's Hunan Province. The 1000-kilovolt transmission line was officially put into operation on Sunday. (Xinhua/Chen Zeguo)

Staff workers inspect Xiaoxiang station of the ultra-high voltage transmission line of Nanchang-Changsha in Changsha County of Changsha City, central China's Hunan Province, Dec. 26, 2021. The 1000-kilovolt transmission line was officially put into operation on Sunday. (Xinhua/Chen Zeguo)