Are trolley-assist haul trucks the next advancement for Minnesota mines?

June 30, 2021

In their quest to leverage renewable energy sources to reduce environmental impacts, Minnesota Power and iron-ore mining companies are exploring technology that would transition mine trucks from diesel fuel to combined diesel fuel and electric power. Transferring electricity to trucks through application of trolly-assist technology, already used at some international mining operations, can help mines reduce emissions and achieve sustainability goals.

Recently, Barr helped Minnesota Power evaluate the feasibility of deploying electric-drive mine trucks with trolley-assist technology. Barr collaborated with the power utility and manufacturers/vendors to assess economic and non-economic trolley-assist considerations. The economic analysis centered around concept and technology application to both small- and large-model mining operations in Minnesota and incorporated feedback from a mining operation that uses the trolley-assist technology in Sweden and Finland.

We performed a sensitivity analysis to illustrate the potential costs and benefits of trolley-assisted mine trucks for a range of operating scenarios, which will be useful for preliminary screening of mine sites and help target further study. Some of the key considerations include slope/grade of primary haul routes, haul distance, diesel fuel costs, and annual tons of ore mined and life of mineable resource. We also evaluated the infrastructure and equipment needs, performed economic modeling comparing upfront infrastructure and equipment costs to the payback period, and considered opportunities for emissions reduction of a broad range of pollutants and for achieving sustainability goals.

Completing a mine-specific feasibility study and an on-site pilot project will help to evaluate the technology further and confirm the feasibility and value of the conversion to diesel-electric mine trucks with trolley-assist.

About the author

Tom Radue has over 35 years of experience with geotechnical and geo-environmental engineering. He assists clients in all project phases from feasibility studies and alternatives analyses to permitting and design, construction quality control, operations assistance, and reclamation and closure.