The film tells about the Unified Energy System of the USSR, necessary for the distribution of electricity within this system, located in different time zones of our country. View of the Main Energy Shield of the Unified Energy System of the USSR. Dispatchers at work. The movement of trams and trolleybuses on the streets of Moscow, the work of industrial enterprises, the lights of advertising and illumination on the streets of the city. View of Volgograd, Volzhskaya hydroelectric power station, Krasnoyarsk hydroelectric power station, Zaporozhye state district power station, Leningrad nuclear power plant, power lines.