This plant is located alongside the river Tajo in the municipal area of Trillo, in the province of Guadalajara. At this plant, 85% of the investment made was Spanish in origin.

The preliminary authorisation, awarded on 4th September 1975,confirmed the proposed site and defined the characteristics of the project. In 1979 the construction permit was issued and in 1988 the plant coupled to the grid.

Since the very beginning, the plant has given great importance to the maintenance of open communications with society in general, and most especially with the inhabitants of the surrounding area, the Alcarria. The plant has set up various channels of information to meet this objective, among them the magazine "Alcarria Alta", the monthly informative bulletin "Central de Trillo I" and reports on activities, and various other activities and publications in the area, as well as the organisation of Cultural Encounters.

The Information Centre began its activities in 1981, and since then more than 280000 people have visited the plant, representing more than 12000 visitors a year on average.

The team working at the plant consists of some 400 employees, supported by special services provided by contracted companies.

The plant collaborates with the surrounding area in activities relating to culture, education, procurement and the improvement of services. The annual refuelling outages mean the incorporation of some 1000 workers.

The owners of Trillo are: Iberdrola (48%), Unión Fenosa (34,5%), Hidrocantábrico (15,5%) y Nuclenor (2%). (Nuclenor is 50% Endesa y 50% Iberdrola)

During 2009, Trillo produced 7702 millions of kWh. This unity had in June 2010 an cumulative gross of 175.683.471 MWh.