Aerial photo taken on May 1, 2020 shows electricians working at the construction site of an ultra-high voltage (UHV) direct-current (DC) transmission line in northwest China's Shaanxi Province. Nearly 10,000 electricians from across the country are building the Shaanxi section of the ±800-kv UHV DC transmission line between northwest China's Qinghai Province and central China's Henan Province. (Xinhua/Tao Ming)

Aerial photo taken on April 30, 2020 shows electricians working at the construction site of an ultra-high voltage (UHV) direct-current (DC) transmission line in northwest China's Shaanxi Province. Nearly 10,000 electricians from across the country are building the Shaanxi section of the ±800-kv UHV DC transmission line between northwest China's Qinghai Province and central China's Henan Province. (Xinhua/Tao Ming)

An electrician climbs with the help of a rope to the construction site of an ultra-high voltage (UHV) direct-current (DC) transmission line in northwest China's Shaanxi Province. Nearly 10,000 electricians from across the country are building the Shaanxi section of the ±800-kv UHV DC transmission line between northwest China's Qinghai Province and central China's Henan Province. (Xinhua/Tao Ming)

Aerial photo taken on April 30, 2020 shows electricians working at the construction site of an ultra-high voltage (UHV) direct-current (DC) transmission line in northwest China's Shaanxi Province. Nearly 10,000 electricians from across the country are building the Shaanxi section of the ±800-kv UHV DC transmission line between northwest China's Qinghai Province and central China's Henan Province. (Xinhua/Tao Ming)