This plant is located in the town of Ascó, in the district of Ribera d'Ebre in the province of Tarragona. Cooling for the two groups is provided by the river Ebro.

Authorisation for construction of group I was granted by the Ministry of Industry and Energy (MINER) in 1974, the other group being authorised in 1975.

The right to use the cooling water was awarded in 1977, and following the granting of the operating permit by the MINER in 1982, the first group was connected to the grid in 1983, followed by the second in 1985.

Integration of the plant into its surroundings has been achieved by building confidence in the reliability and safety of operation of the facility over the years, and by collaborating in activities of general interest promoted by local cultural and sports associations, this having been done without protagonism and with a vocation to be one member more of the local community. Likewise, collaboration agreements have been set up with the Teaching Department of the Regional Government of Cataluña and with the Rovira i Virgili University of Tarragona, in order for the Secondary School students of the area and the students of the aforementioned University to be able to carry out practical exercises at the plant installations.

The land around the plant (and owned by it) has been used to cultivate vines, olives, fruit, etc., as a result of which the surroundings have not suffered any deterioration.

The electricity company Endesa is the only owner of Ascó I.

During 2009 Ascó I produced 5770.74 millions of kWh. This unity had in June 2010 an cumulative gross of 189.052.542 MWh.