Cardones-Polpaico Transmission Line

This electric transmission project, one of the most important in the last 50 years in Chile, allowed the real interconnection of the National Electric System at 500 kV, for the direct benefit of millions of Chileans, who, in addition to having more robust, safe, reliable, and higher capacity electric transmission infrastructure to face operational contingencies, will be able to take advantage of the socio-environmental benefits of receiving clean energy from renewable sources from the north of Chile. The start-up of Cardones-Polpaico means that today, about 1,000 MW of additional renewable energy is being transported through the National Electric System.

Enabling a true and unprecedented energy transformation in Chile, Cardones-Polpaico substantially expands the country’s electricity transmission capacity, making it possible to enter and transport renewable energy from wind and photovoltaic sources to large consumption centers that previously had their contribution to the grid restricted. A direct benefit of having a 500 kV double-circuit line is that renewable generators can inject all the clean energy they produce into the system by increasing transmission capacity. The above implies that, by adding new sources of renewable energy, the decarbonization process gains strength through the progressive closure of coal-fired power plants, a plan recently announced by the Government.

Aware of the magnitude of this project, ISA INTERCHILE made extraordinary resources and capabilities available to put this project of national interest into operation, thanks to the effort and commitment to Chile of more than 5,000 people and 300 companies from different specialties from 20 different countries that were part of this project from its inception.

The project involved the construction of 1,728 high-voltage towers along 753 kilometers of Cardones-Polpaico, crossing the regions of Atacama, Coquimbo, Valparaiso, and Santiago. More than 5,000 people participated in the construction works, in addition to 300 supplier companies and service providers in construction, assembly, cargo transportation, and personnel transport both on land and air.

ISA's presence in energy transport in Chile

2x 500 kV


1000 mm

Investment (USD)

753 km


Cardones-Polpaico 2 x 500 kV transmission line

Benefits for Chile of the Cardones-Polpaico line


More robust system

Compliance with the Energy Agenda projected by the government, delivering greater security, reliability, and sustainability to the electrical systems through the electric interconnection.


Lower costs

It will allow for lower electricity tariffs for people and businesses.


Greater competition

Enables the entry of new actors, promoting investment in the country.


Incorporation of Renewable Energy into the system

Allows for the entry of clean energy into our electrical system.


Regional interconnection

Will be part of a regional electrical interconnection in South America.