In its first official release on the project, copper mining major Collahuasi has stated that for the first time in Chile – and all of South America – an electric trolley assist system for mining trucks is now up and runnung at its operations. As recently revealed by IM, this landmark pilot project was already in testing in June but officially began in July at Compañia Minera Doña Inés de Collahuasi’s Rosario open pit, situated at over 4,600 m above sea level in the Tarapacá Region.
In its first phase, the project electrifies a critical 1 km uphill segment between the mine and the waste dump – where energy demands peak during loaded ascents. Four Liebherr T 284 haul trucks, each with a payload capacity of 365 t, have been equipped with pantographs that connect to an overhead catenary system via retractable arms, powering the electric motors during this stretch. As a result, diesel consumption drops by ~98%, and CO₂ emissions fall by 97.6% on this section.
“The trolley assist system is a mature technology that enables tangible progress in decarbonising our operations. It’s a viable, scalable solution suited to our terrain, without requiring full fleet replacement,” said Dalibor Dragicevic, Executive VP of Operations at Collahuasi.
The system is powered by 100% renewable electricity via a substation, two transformers, and a rectifier station. Every dieseltoelectric conversion therefore contributes to netzero emissions, reinforcing Collahuasi’s commitment to sustainable mining.
“We envision an increasingly electric operation, with most of our energy consumption sourced from clean power. The trolley pilot initiates a staged evolution toward more complex solutions, such as electric or hybrid autonomous trucks. In ten years, we expect a significant reduction in diesel usage across our sites,” Dragicevic added.
In addition to its environmental benefits, this technology enables greater operational efficiency by more than doubling the speed on the electrified segment – from an average of 11 km/h to 25 km/h – resulting in a saving of approximately two minutes per cycle. It also reduces equipment wear, lowers maintenance costs, and extends truck lifespan.
“Electrifying 365-metric-tonne mining trucks operating at high altitude and in extreme conditions is a significant technical challenge, but also a major opportunity for large-scale mining. The trolley system will drastically reduce diesel consumption and greenhouse gas emissions, while improving haulage speed, contributing to a more efficient and sustainable operation,” said Marcos Márquez, Director of the Mine Process Electrification Project.
Chilean engineers led the deployment in collaboration with Liebherr Mining and Chilean suppliers like Grupo Saesa (STN), tailoring the design to withstand extreme altitude, wind, and seismic conditions – setting a new benchmark in regional mining innovation.
This pilot serves as a foundation to evaluate extending trolley assist across other high demand segments. “Haul trucks account for a substantial portion of our emissions. Electrifying high energy segments in haul routes is highly effective. This pilot models realworld impact, explores scalability, and enables replicable solutions,” said Verónica Cortez, Collahuasi’s Energy Manager.
“This project directly supports our decarbonisation target by replacing diesel consumption with electricity sourced entirely from renewables. Trolley assist demonstrates that it is possible to operate efficiently, profitably, and in an environmentally responsible way simultaneously,” Cortez noted.
Other mining operations in Chile are currently exploring similar alternatives, still at the pilot design stage. With this implementation, Collahuasi becomes the first major mining company to bring this technology into operation, reaffirming its leadership in innovation, energy efficiency, and sustainability.
Trolley assist is a key element of Collahuasi’s operational transformation roadmap, which integrates automation, digitalisation, and electrification as pillars for a competitive, responsible mining industry aligned with top-tier ESG standards.