Chile’s national grid operator has conducted its first field tests of grid-forming technology at Engie’s Los Loros BESS in the Atacama region.
The National Electricity Coordinator, Engie Chile and Huawei carried out the tests at the Los Loros BESS, which is integrated with the Los Loros solar PV plant in the municipality of Tierra Amarilla.
During the tests, Power Block No. 1 operated in grid-forming mode and participated in the formation of an electrical island. According to the National Electricity Coordinator, the system maintained stable voltage and frequency on the isolated grid during the test.
The tests are intended to provide operational data to support the development of verification criteria for grid-forming technology and its integration into Chile’s National Electricity System (SEN). The work forms part of the grid operator’s technical process for defining requirements for inverter-based resources capable of forming a grid.
Unlike grid-following (GFL) inverters, which operate by following existing voltage and frequency references, grid-forming equipment can establish those references and respond autonomously to changes in the power system.
The National Electricity Coordinator’s requirements for grid-forming resources include autonomy and synchronization, fast voltage and frequency control, islanded operation and oscillation damping. The equipment must also maintain stable operation on very weak grids and in passive systems.
The operator began formalizing this framework in October 2024, when it published recommendations for minimum technical requirements for grid-forming and grid-following technologies. It published the final grid-forming requirements in April 2025. Huawei Digital Power, along with SMA Solar Technology, was already participating in the process through collaboration agreements covering technology testing and validation.
In May 2026, the operator published its Guide for the Verification of Grid-Forming Inverter-Based Installations. The document covers pre-connection checks using models and laboratory tests, field tests and monitoring during commercial operation. The National Electricity Coordinator said the guidelines would be complemented by results from pilot projects.
Los Loros entered commercial operation at the end of August. Engie currently reports a maximum gross power output of 48 MW and storage capacity of 275.23 MWh. The system comprises 63 lithium iron phosphate (LFP) battery containers, required an investment of $64 million and is integrated with the Los Loros solar PV plant.
During its energization phase, which began in March, Engie reported a configuration of 46 MW and 230 MWh. At the time, it said the BESS connects to the 110/23 kV Los Loros Solar Park substation and is designed to store part of the solar plant’s daytime generation for later delivery to the grid.
Grid-forming technology is also being incorporated into other storage projects under development in Chile. In August, Enel Chile began construction of the 100 MW Finis Terrae BESS in the Antofagasta region, which will use the technology.
In the Atacama region, Atlas Renewable Energy and Trina Storage are developing the Copiapó PV + BESS project, comprising 233 MW of solar PV and 932 MWh of storage with grid-forming technology.