Chile’s Coordinador Eléctrico Nacional (CEN) has released its Preliminary Transmission Expansion Proposal for 2026, a technical roadmap that defines the country’s priority investments in power grid infrastructure.
The plan recommends the execution of 43 transmission projects, with a reference investment of USD 647 million, aimed at strengthening security of supply, fostering competition and enabling Chile’s energy transition.
According to the proposal, USD 254 million will be allocated to nine projects within the National Transmission System, while USD 393 million will fund 34 projects across the Zonal Transmission Systems.
The planning scenarios consider annual electricity demand growth of up to 5.2%, particularly under a high-impact scenario driven by the large-scale deployment of green hydrogen, making grid reinforcement a critical enabler of future investment in renewables and electrification.
National Transmission System: easing congestion and integrating renewables
For the National Transmission System, the CEN proposes two new projects and seven network expansions.
In Northern Chile, the strategy focuses on mitigating high daytime congestion risks along 500 kV and 220 kV corridors, which are essential for evacuating solar and wind power. To address this, the plan includes the installation of 750 MVA autotransformer banks at the Nueva Lagunas and Kimal substations, designed to facilitate the efficient integration of variable renewable energy (VRE).
In the central zone, congestion risks exceeding 30% from 2036 onwards are projected at the Polpaico, Lo Aguirre and Alto Jahuel substations. Mitigation measures include new transformation equipment and capacity upgrades on the 2×220 kV Polpaico–Cerro Navia line.
The proposal also highlights the construction of the new 2×220 kV Manuel Rodríguez–Agua Santa line and the new Lo Curro substation, considered critical for improving power transfers and supply reliability in Greater Santiago and the Valparaíso region.
Zonal transmission: electromobility and energy storage
Zonal planning covers the entire country, from Arica to Chiloé, with the Metropolitan Region accounting for the largest share of zonal investment: USD 132.6 million across eight projects.
Among these, the CEN underscores the replacement of transformers at the Santa Marta substation, explicitly justified by rising demand linked to electric mobility in the Maipú district, driven by public transport electrification tenders.
A key innovation in the 2026 proposal is the formal inclusion of battery energy storage systems (BESS) as a transmission solution. In the Alto Jahuel–Charrúa area, the plan allocates USD 79.6 million to install BESS at the El Monte, El Paico, Panguilemo and San Rafael substations.
These storage assets are intended to secure supply for end-users and maintain grid stability while longer-term transmission infrastructure is developed.
Investment breakdown by zone
| Zone / System | Number of projects | Type of works | Reference investment (USD million) |
|---|---|---|---|
| National Transmission System | 9 | 2 new / 7 expansions | 254.0 |
| Arica – Diego de Almagro | 7 | New and expansions | 57.5 |
| Diego de Almagro – Quillota | 9 | New and expansions | 95.7 |
| Valparaíso Region | 1 | Expansion | 6.0 |
| Metropolitan Region | 8 | 3 new / 5 expansions | 132.6 |
| Alto Jahuel – Charrúa | 6 | New and expansions | 79.6 |
| Charrúa – Chiloé | 3 | Expansions | 21.6 |
| Total | 43 | 647.0 |
Warning over delays and failed tenders
Beyond new investments, the CEN dedicates a specific chapter to projects affected by failed or delayed tender processes. The report warns that non-execution of certain works could compromise short-term adequacy and security of supply.
Critical risks have been identified at substations such as Molina, San Clemente and Linares in the Maule region, as well as delays in the expansion of the Tamarugal substation in Tarapacá.
In response, the grid operator recommends assessing emergency or fast-track mechanisms to accelerate the development of this critical infrastructure.
The document remains in a public consultation phase, allowing companies and stakeholders to submit technical comments before the CEN submits its final recommendation to Chile’s Comisión Nacional de Energía (CNE).
