Many factors affected the development of the transmission network, such as economic development of a country, population density, location of natural energy resources and big industrial facilities, etc. In Serbia, the term ’transmission network’ related to power lines and power facilities of 110kV voltage level and above (relevant standardized voltage levels of 220kV and 400kV). If we would refer to the afore mentioned criteria, transmission network as such practically did not exist in the period between 1893, when the era of electrification of Serbia started and the Second World War. But, as of the year 1945 the rapid development was being on the way in terms of construction and formation of networks.
The first power transmission in Serbia was accomplished more than a century ago (in 1903 HPP Vučje – Leskovac), but at the voltage level on which the distribution systems operate, if strictly following the stated criteria. First power line connections were set up in the period between two world wars for the needs of a rudimentary power transmission. Significant volumes were transmitted in 1938 when TPP Vreoci was commissioned. Overhead power lines from TPP Vreoci to Belgrade and TPP Vreoci to Aranđelovac were built and put into service, but at 60 kV voltage level. At the same time, 35 kV level was introduced (Kragujevac, Čačak, Kraljevo and Jagodina). By putting these lines into service, the first 60 kV and 35 kV networks, respectively, were created in the sectors of Belgrade, Kragujevac and Vreoci. In the course of the Second World War, two overhead power lines were built to connect the following facilities: substation (SS) Makiš – SS Beograd 2 (60kV level) and Belgrade – Kostolac. The latter was built to operate at 110kV but was first running at 15kV level.
After the Second World War the country faced the age of industrialisation and electrification. Construction of power generation and transmission facilities started. A first typified transformer station 110/35kV Jagodina 1 was commissioned in 1952. Concurrently, the power overhead line Kostolac – Petrovac – Svetozarevo (Jagodina) was put into operation at 110kV level. Only three years after its commencement, the project of building a ring of 110kV power lines Beograd – Kruševac – Sevojno – Kolubara – Beograd was completed. In the same year, i.e. in 1955 Serbian 110kV transmission network was connected to Bosnia and Herzegovina’s 110kV network via HPP Zvornik, and in December 1957 110kV networks of all Republics of the former Yugoslavia were connected to run in parallel.
In the following year (1958) a power transmission company named Elektroistok was established within the Joint Power Industry of Serbia. A rise of an important segment of the power industry commenced – the rise of a power grid that connects scattered electricity generation and consumption areas. The rise was achieved by increasing the number of power lines and facilities, introducing new voltage levels and higher-capacity facilities, and enhancing the professional potential of the personnel. Incorporating these components with power system control component made the company grow into the company Elektromreža Srbije. Since its establishment and registration in the Business Registers Agency the Public Enterprise Elektromreža Srbije, of Belgrade, acted in the capacity of a legal entity. In legal and business operations it acted on its own behalf and for its own account with sole responsibility. On 8 November 2016 the company took a new legal form of the closed joint stock company with Republic of Serbia as its sole owner, without the option for natural persons or legal entities to buy its shares.
Elektromreža Srbije Joint Stock Company Belgrade celebrates 28 June as its Company day, because on 28 June 1958 the first Serbian transmission company was founded and the Joint Electric Power Industry of Serbia embodying the role of a power system control was established on 28 June 1965.