The firm, a majority-owned subsidiary of the Italian utility company Enel, has 10 million customers in Spain, with domestic annual generation of over 97,600 GWh from nuclear, fossil-fueled, hydroelectric, and renewable resource power plants.

Endesa carries out activities of generation, distribution and commercialization of electricity, natural gas and renewable energy through Enel Green Power.

The company was formed in 1944 as Empresa Nacional de Electricidad, S.A.; its first president was Esteban Terradas, and its first CEO was Juan Granell Pascual.

[3] Compostilla I was its first production plant, whose construction began in 1945, being inaugurated in Ponferrada, capital of the Leon region of El Bierzo, on July 28, 1949.

[4] At the same time that Endesa began its operations in Ponferrada, the shortage of electricity in specific parts of the country was noted, with no possible short-term solution.

For all this, Endesa bought ten mobile units to deal with critical situations with the electricity supply in Seville, Barcelona, Cartagena, Asturias and Mallorca.

[7] The opposition People's Party of the day, and some Madrid politicians, criticised the bid, alleging political interference by the Socialists and a Catalan nationalist plot to control energy supply respectively.

[citation needed] The German firm withdrew its bid two months later in exchange for a promise from rival bidders to sell it part of the Spanish utility's assets.

The Enel Green Power Spain operating figures are as follows today: In Europe, Endesa is the only Spanish company involved in the ELVIRE (Electric Vehicle Communication to Infrastructure, Road Services and Electricity Supply)[18][19] and G4V (Grid for Vehicles)[20] consortia aimed at developing the necessary technology, solutions and services to enable ongoing interaction between drivers, their power suppliers and the smart grid.