Companhia de Interconexão Energética (CIEN) is a Brazilian privately held company, controlled by Enel Brasil, and engaged in the generation, industrialization, distribution and trading of electric power, including imports and exports. The company -based in Niterói, Rio de Janeiro state- manages the Garabi I and Garabi II substations and transmission lines, which convert power frequencies between Brasil and Argentina (50hz and 60hz, respectively). In 2015, Cien inaugurated the new 22km segment of the Itá-Garabi 2 line, with segmentation and interconnection of the Santo Ângelo substation. The same year, the firm transmitted 259.73GWh and it also converted the frequency and exported 53.74GWh to Argentina. Incorporated in 1997, CIEN has a total of 745.2km in transmission lines.