The president of Chile, Sebastián Piñera, inaugurated the Cardones-Polpaico transmission line on June 20, 2019. The 753-km long transmission line will transport up to 1,500 additional MW of renewable energy from the north of the country, where most of Chile´s renewable plants are located to the consumers in Chile´s south. The project involved a foreign investment of USD 1 billion.
The project is considered the most important electric power transport infrastructure to be built in Chile in more than 30 years and it was developed by the Colombian company Interconexión Eléctrica SA (ISA).
The new transmission line will strengthen the interconnection of the National Electrical Power Grid, uniting the Northern Electrical Power Grid (SING) and the Central-Southern Grid (SIC). It consists of 1,728 pylons located in 20 municipalities in the regions of Atacama, Coquimbo and Valparaíso along with the Metropolitan Region. Approximately 5.7 million homes will receive electricity from renewable energy plants located in the north of the country, especially photovoltaic and wind power installations.
The project was divided into three sections:
Section 1 is located in the Atacama region and connects the Nueva Cardones and Nueva Maitencillo substations through a 500 kV double circuit line with a length of approximately 134 kilometers, as well as a 5 km linking line of 220 kV between the Nueva Cardones substation and the existing Cardones substation. This section has been in operation since January 2018.
Section 2 runs between the provinces of Huasco and Elqui, and links up the Nueva Maitencillo and Nueva Pan de Azúcar substations through a 500 kV double circuit line of approximately 212 kilometers. It also includes an approximately 1 km long linking line of 220 kV between the Nueva Maitencillo substation and the existing Maitencillo substation. This section began transmitting electric power in April 2018.
Section 3 spans the regions of Coquimbo, Valparaíso and the Metropolitan Region, in a route that passes through the provinces of Elqui, Limarí, Choapa, Petorca, Quillota, Marga Marga and Chacabuco.
The Nueva Pan de Azúcar and Polpaico substations are connected through a 500 kV double circuit line of approximately 408 kilometers in length. It also includes an approximately 23 km 220 kV linking line between the Nueva Pan de Azúcar Substation and the existing Pan de Azúcar Substation. This line began transmitting electric power in May 2019.