The end of the 19th century and the beginning of the 20th century were marked by an explosion in uses for electricity, including the electrification of tramways, subways and railways. Electric companies began to open in major cities. At the time, companies used a variety of frequencies and voltage levels, without considering the possibility of interconnecting networks.
Electric companies quickly realised they needed to help one another in order to continue supplying customers with electricity during outages. They decided to adopt the same technical standards, thus making it possible to connect networks together. When plans for rural electrification began to appear, the development of the distribution network faced a cost problem. As a solution, the system of public service concessions was created. Through these concession contracts, municipalities subcontracted third-party companies for the construction of electrical infrastructure. In turn, these companies operate the network and collect fees for its use.
Through this system, the network rapidly grew at the local level through the efforts of private electricity companies. The number of French municipalities with electricity went from 7,000 in 1919 to 36,500 in 1938. Companies were compelled to collaborate in order to interconnect their electricity transmission networks, creating common specialised companies for this purpose. The early 1930s saw the first large capacity (220,000 volts) interconnections between electricity-producing regions (notably the Alps) and the French capital. In just a few years, France gained a large interconnected network of 220,000 volts.
The French government intervened in the interests of the general public. In 1938, it launched a national interconnection plan to bring electricity to all regions of France. The programme called for an investment of 3 billion francs over 5 years, which comprised 1.5 billion to increase hydraulic production by 50% and 1.5 billion to build 4,000 km of electricity transmission lines. At the time of France’s liberation, the transport network was one of the densest in the world, with 22.5 km of lines carrying more than 100,000 volts per 1,000 km2 (compared with 5 km for the United States, 15 for Great Britain and 18 for Germany).
On April 8, 1946, the law nationalising French electric companies was approved by vote. A new public establishment, Électricité de France (EDF), was created. It integrated electricity production, distribution and transmission companies. EDF became an essential instrument in the reconstruction of France. Electric companies owned by municipalities were not nationalised, as they were extensions of public organisations. These companies now represent the local distribution companies (ELD).
The primary mission of EDF consists in managing shortages. Electricity distribution depends on national and regional priorities. Due to a lack of sufficient energy resources, it was necessary to organise temporary electricity outages until 1950. The public company’s next task was to harmonise the standards inherited from the nationalised companies. As such, 225,000 volts gradually replaced 150,000 volts, and the frequency of 50 Hz also became standard all across France (it was formerly 25 Hz across much of the Mediterranean coast).
From 1950 to the 2000s, the network developed as electricity consumption increased. The 400,000-unit voltage , developed in 1946, was adopted as the European standard. First implemented in the 1960s, it was then deployed throughout the following 2 decades, just as nuclear energy production began to progress. Interconnections with neighbouring countries were developed in order to support exports.
The law of February 2000 introduced the gradual opening of the electricity supply market to competition, in compliance with the commitments of the European directive of 1996, which it adapted for France. The law:
- defines public service duties in matters of electricity and treats their financing,
- provides for the creation of an independent Transmission System Operator,
- provides for the financial separation of network activities,,
- creates the Commission de Régulation de l’Énergie (CRE), the French regulatory body for energy, which contributes to the proper functioning of the electricity and natural gas markets,,
- provides for non-discriminatory access to the electricity network for all users.
In July 2000, EDF created an autonomous division dedicated to managing the electricity transmission network, the RTE (Réseau de Transport Électrique, French TSO).
June 2003, a 2nd European directive required the legal separation of the Transmission System Operator and the Distribution Network Operator.
The following year, in compliance with the law of August 9, 2004, which adapted this directive for France, EDF operationally separated its activities:
- production and supply entered the competitive sector,
- transmission and distribution remained regulated activities.
For distribution, EDF thus created:
- a functionally independent management service for the distribution network, EDF Réseau Distribution (ERD),
- a common operator with Gaz de France, EDF Gaz de France Distribution (EGD).
The law also called for the legal separation of the electricity Transmission System Operator (RTE).
The law of December 2006 relating to the energy sector perfected the system by:
- adding to the distribution manager missions,
- planning for the legal separation of distribution network managers (having more than 100,000 customers) through the transfer of distribution assets, rights and obligations to these managers,
- adapting the measures that guarantee the independence of managers,
- requiring the creation of a service held in common between gas and electricity subsidiaries.
ERDF, a subsidiary of EDF in charge of the public distribution of electricity (Distribution Network Operator), was created on January 1, 2008.