Electric power companies of Spain

Iberdrola, S.A. () is a Spanish multinational electric utility company based in Bilbao, Spain. It has around 40,000 employees and serves around 30 million customers.

'Naturgy Energy Group S.A., formerly Gas Natural Fenosa''''' (), is a Spanish multinational natural gas and electrical energy utilities company, which operates primarily in Spain. The company's administrative headquarters are in Barcelona, while its legal headquarters are in Madrid.

Endesa, S.A. (, originally an initialism for Empresa Nacional de Electricidad, S.A.) is a Spanish multinational electric utility company, the largest in the country. 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. Internationally, it serves another 10 million customers and provides over 80,100 GWh annually. Total customers numbered 22.2 million as of December 31, 2004. It also markets energy in Europe.

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