1879 – The first year of the modern history of Bulgaria. The year when the Turnovo Constitution was adopted, Alexander Battenberg was chosen as the first prince (kniaz) of modern Bulgaria, the first Bulgarian government was headed by Todor Burmov. This is the same year when Sofia was proclaimed capital of the recently created Principality of Bulgaria. The aim of the municipality authorities at the time was to develop the city so that to erase the memories of the dark centuries of the Ottoman yoke. That is why one third of the first budget of the capital was allotted for “better city lighting and increasing the number of its lanterns”. The lighting of the city had been among the priorities of the municipality authorities even before the adoption of the decision to use electricity for lighting the streets of Sofia.

1879 – Thomas Edison invented the incandescent filament bulb.

1 July 1879 – The first electric bulb in Bulgaria commemorated the succeeding of Alexander Battenberg to the throne. On this occasion Plovdiv newspaper The Maritsa wrote: “We witnessed a wonderful illumination yesterday. The garden, opposite the palace was magnificently decorated…Doctor DimitarMollov delivered from Viennaequipment andother devicesfor generating electric sun, which illuminated the whole garden and the town clock…Lanterns of various colour, most of which were hanging from strange wires, connected the top of the pavilion to the trees around to form a wonderful cone, emitting rays which mingled with the rays of the electric sun.” We can presume that the “electric sun”, described in The Maritsa newspaper, was acarbon arc lamp.

The historicevent from1879was not only the first time electricity wasused in Bulgaria, but probably on the Balkan Peninsula as a whole. In those years, when the “magic light” twinkled hereand there inrecently liberated Bulgaria,the epochalinventions inelectrical engineering wereborn.They boosted the implementation of electricity in everyday life.This was the time when the classic electric bulb had just been invented.

1889 - Dolivo –Dobrovolski inventedthe three-phase alternating currentengine.  

12 July 1890 – the mayor Dimitar Petkov (1888 -1893) appointed a commission to explore the opportunities for electricity lighting in Sofia. The commission recommended the construction of a hydropower plant, using the waters of the Boyanska and the Vladaya rivers. Buried (cable) city network was recommended, of load capacity three times exceeding the initial one. The electricity distribution was intended to be managed by a central point and to have a telephone connection with the station. The progressive idea for street electricity lighting belonged to the mayor Dimitar Petkov. He committed himself to the ambitious task to reconstruct the city and to make it look like a modern European city. At that time most of the large European cities were lighted with gas lanterns. The mayor and the Municipality preferred to consult a number of companies regarding the opportunity to use electricity for city lighting. And although somepublicfigures, including Prof. Konstantin Irechek, doubted the success of the project, it was implemented. With the active help and personal involvement of the Minister of Internal Affairs Stefan Stambolov “…the dreams of supplying electricity using the Boyana Riverwater power” came true.

1891 – The first three-phase transfer of electricity (alternating current) for the exhibition in Frankfurt am Main (Germany) of 16V voltage at the distance of  175 km and transferable power 147,2kW (200hp).

July 1891 – Ganz&Co got the first contract for the implementation of the large-scale project for street lighting. A year later started the construction of the first Bulgarian electricity power plant – HPP Boyana.

April 1898 -  commencement of the construction of HPP Pancharevo on the Iskar River. Commencement of the preparation works on the electricity network of the city -  transformer units, HV and LV cables, posts.

1^stNovember 1900 - HPP Pancharevo was put into operation together with the street lighting of Sofia. It was the beginning of the public electricity supply in Bulgaria. The capital of Bulgaria ranked among the first European cities of extensive use of electricity for public needs.

At the time Sofia was of population 68 000 people, who celebrated the new acquisition of the city with a magnificent party to put a symbolic end to the dark ages in our history. The first private customers of electricity lighting were only 17. But the interest to electricity boomed and in the very next year the number of customers totaled 250 people.

1^stNovember 1900 - Commencement of the routine operation of the electricity network of Sofia.

1901 - The generation of electricity at HPP Pancharevo reached 2,5х10/6/kWh, and the consumption -- 1,4х10/6/ kWh. The electricity supplier provided electricity for 249 customers, 600 street lighting lamps and an electric tramway.

1906 - The mayor of Pleven TodorTabakov presented for the firsttime the idea to electricify the city. On 2^nd April, 1907 a public tender of covert competition for contracting the electrification works was announced.  The tender was not held for breach of the legal requirements. A new tender was announced a few months later. But on 9^th May 1908 the municipality council was dissolved, Todor Tabakov was removed from the mayor’s office and the implementation of the made decisions – postponed.

1910 – The mayor of Pleven Angel Danov tabled for discussion the question of elictrification of the city.  A tender was announced and only two companies submitted proposals – Siemens and Shucker-Wercker. The latter company got the contract. The works began. The Municipality Council was convinced that in a yearPleven will be one of the few electrified towns. However, the national union wars/1912-1913, 1915-1918/ postponed this initiative for some time.

1914 – To increase the extraction from the pitsthe first electricity capacity was installed in Pernik Mines. A 55 kV generator was put into operation, which was used till 1925 and supplied electricity to the homes of the miners surrounding the pits.

1^st January 1918 – The electricity department at the municipality, which controlled the concession companies that provided for the electricity supply of the capital, was reorganized as Tramway and Lighting Directorate.

1921 - Ferdinand Municipality (Montana) assigned to Nikolov-Kohinov Architectural and Technical Office-Sofia to develop a design for electirifcation of the city. Several years later a contract was signed with Nikola Sapundjiev and Co from the town of Ferdinand for the electricity supply of the town, which was lighted by electric power in September 1928.  

1923 – The first electric bulb was on in Gorna Djumaya when Rozen bros delivered a diesel engine for the town cinema and the street lighting.

1924 – At the time when Ivan Mindilkov was mayor of Pleven, the construction of an electricity plant and the electrification of Pleven became a major concern of the municipality authorities. On recommendation of Tzar Ferdinand the Vienna headquarters of Bergman Company sent its general director Hasler to conduct negotiations. The contract was signed on 7^th November 1925. The works were commenced on 30^th May, 1926, the first dry-run was on 13^th January, 1927 and on 11^th August, 1928 it was officially put into operation and quickly started to play an important role in the economic development of the city.

1924 - the onset of the public electrification of Blagoevgrad. The Trade and Industrial Company put into operation a diesel electricity plant of capacity 400kW.

1925-1940 - This period was closely related to the use of electricity generated by the electricity power stations constructed on the Rilska River. The electricity was transmitted by 60 kV overhead electricity lines of length 100 km.

1926 - The outset of the electrification of Sofia District. (by the end of 1999 Sofia Districtcompletely covered the area, consisting of four economically and geographically distinct regions – the former Sofia, Pernik, Kyustendil and Blagoevgrad regions which at present are separate administrative  centres). In this yearOrion AD,founded in1922,merged in Granitoid AD. The company was a direct investor in HPP Rila, HPP Pastra, HPP Kamenitsa, and the first in the country PHPP Kalin. The related transmission and distribution electricity power lines and substations were constructed together with the construction of the Rila water cascade. The initial voltage intended was 35 kV but soon after it was preferred to use 60 kV which was over three times transmission capacity and was more prospective in view of the needs of electricity transmission.

June 1926 – Substation Orion was put into operation. Orion distribution substation has been a legend in the history of the regional electrification. It is hardly a coincidence that its putting into operation has been considered a turning point in the history of the public electricity supply. It initially operated two transformers 2 000 kVA  each and voltage 35/15kV.After extension of capacity the substation became a linking point of the Rila HPPs and the stations of the Belgium joint-stock company Electricity Company for Sofia andBulgaria and the stations in Sofia.

1926 – The outset of electrification in Svoge.Vasil Peev put a small HPP of capacity 125kW for the needs of the chocolate factory.  

1926 – The small HPP on the Bistritsa River was put into operation.The first residential buildings in Blagoevgrad were supplied with electricity.

1927 – The outset of the electrification of the town of Kyustendil, although the first electric bulb had been on as early as 1911.  Four 6kV/0,4kV transformer units were initially constructed in the town of total capacity200kVA.

1927 - In Ihtiman the Tsonevbros started the operation of an aggregate for industrial needs. Boris Zarev started the operation of the first diesel power plant in Zemen of capacity 14 kW.

1930 – The first diesel power plant was constructed in Pirdop. It was of combined function – for industrial and residential needs.

1944-1970 - The need of new capacities increased. Eight substations were constructed during this period, the transmission and distribution networks were developed, 110kV and 220kV,and later 400kV voltages - used. TPP Sofia and TPP Traicho Kostov were under construction. Then commenced the replacement of the existing cable 150 kVLV network by 380/220kV and of the MV voltage networks from 7kV to 10kV and from15kV to20kV.

1^stJanuary 1948 – A state-owned company Electricity Supply Sofia was established at the Ministry of Energy and Water Resources. In 1958 the company was restructured and renamed to Electricity Supply Stolichno. The company serviced three regions.

2000 – Electricity Distribution Stolichno AD was established after the severance of NEK AD  pursuant to an Order of the State Energy and Energy Resources Agency (at present–Ministry of Economy and Energy). It was a successor of the company Electricity Supply – Stolichno.  

2005 – the state-owned company Electricity Distribution EAD and the companies Electricity Distribution Sofia Oblast EAD and Electricity Distribution Pleven EAD were privatized. The contract for the privatization sale of the shares was signed on 19.11.2004between the Republicof Bulgaria, represented by the Privatisation Agency and CEZ, the Czech Republic.  The procedure for the privatization of EDC Stolichno, EDC Sofia Oblast and EDC Pleven was completed at the beginning of 2005 when the Privatisation Agency endorsed 67% of the shares, purchased by the Czech company CEZ. With a decision of the then Minister of the Energy and Energy Resources Mr Milko Kovachev, in his capacity of a representative of the Republic of Bulgaria as a single owner of the capital of Electricity Distribution Stolichno, Electricity Distribution Sofia Oblast and Electricity Distribution Pleven, the companies adopted a new by-laws and changed their system of management from one-tire to two-tire – of a supervisory board and a management board. Till the beginning of 2007 the companies had still another licence – for public supply of electricity to the residents on the territory they serviced.

3^rdJanuary 2007 - Pursuant tothe requirementsof § 17 from the Transitionaland Final Provisions ofthe EnergyAct the electricity supplyand operativemanagement activities andthe electricitysupply andthe other activities ofthe electricitydistributioncompanies werelegally andorganizationallyunbundled.The electricitysupply activitywas taken overby a newly established companyCEZ ElectroBulgaria AD,a successorof the electricity supplyactivity of Electricity Distribution Stolichno AD, Electricity Distribution Sofia Oblast AD and Electricity Distribution Pleven AD.

2^ndNovember 2007 – Electricity Distribution Sofia Oblast AD,Electricity Distribution Pleven AD and Electricity Distribution Stolichno AD merged. In practice the two distribution companies Sofia Oblast andPleven incorporated into Stolichno. The aim of the restructuring is to optimize the activities of the three electricity distribution companies on the territory ofWestern Bulgaria, to improve their management and to achieve higher efficiency. This will create conditions for the same quality of customer service in all Western Bulgaria and for the introduction of consistent policy for the electricity network maintenance and development.

29 January 2008 - With a decisionof Sofia CityCourt Electricity DistributionStolichno AD was renamed to CEZ Distribution Bulgaria AD.