The project reuses existing infrastructure at a site originally conceived for thermal generation expansion. Assets repurposed for the battery installation include the interconnection substation, internal access roads, and designated land areas within the complex. This approach allowed the company to deploy grid-scale storage without constructing entirely new infrastructure, reducing both capital requirements and development timelines. The final installed capacity of 142 MW exceeds the 140 MW initially announced in October 2025 when the project was first disclosed with a planned second-half 2026 commissioning date.
BESS Lile functions as a stand-alone system connected directly to Chile’s National Electricity System. The configuration allows the battery to store electricity and dispatch it to the grid according to system requirements, supporting the integration of variable renewable generation. The facility operates independently rather than being paired with a specific solar or wind plant, providing flexibility for grid operators to manage supply and demand imbalances across the network.
The commissioning follows the December 31, 2025 disconnection of coal-fired units CTM1 and CTM2 at the same Mejillones complex after nearly three decades of operation. Engie simultaneously converted the Infraestructura Energética Mejillones unit to operate on natural gas, with that 377 MW facility awaiting final authorization for commercial operations as of mid-October 2026. The broader transformation plan includes future retirements of the coal-fired Central Termoeléctrica Andina and Central Termoeléctrica Hornitos units as part of the company’s phased coal exit program.
With BESS Lile operational, Engie reports five battery storage systems commissioned during 2026, totaling 803 MW of installed capacity across Chile. The year’s additions include the 116 MW/660 MWh BESS Tocopilla and 25 MW/150 MWh BESS Arica. In August 2026, the company announced BESS Libélula and BESS Los Loros with combined capacity of 251 MW and $283 million in investment, further expanding its storage portfolio across multiple regions.
This article was curated and published as part of our South American energy market coverage.
