Rolls-Royce Power Systems is developing a new hybrid drive system for mining haul trucks aimed at reducing fuel consumption and carbon emissions in open-pit mining operations. The company plans to begin field testing the technology at a mine site from autumn 2026.
The hybrid solution combines proven mtu Series 4000 diesel engines with a high-performance electric drivetrain. According to the company, the system could reduce fuel consumption and CO₂ emissions by up to 30% compared with conventional haul truck drive systems, depending on mine topography and operating conditions.
The concept was presented by Alexander Richter, Chief Engineer for Hybrid Mining Trucks, during The Electric Mine 2026 held in Lisbon on 7 May 2026.
The hybrid system captures braking energy generated during downhill travel and stores it in onboard batteries. This energy is then used to power the wheel motors during uphill operation, reducing the load on the diesel engine and lowering fuel use.
Rolls-Royce says the system is being designed as a modular and scalable platform that can be adapted for different haul truck models, mine layouts and operational requirements.
According to Cobus van Schalkwyk, the mining industry is under increasing pressure to improve efficiency while reducing emissions.
He noted that haul truck transport in open-pit mining represents one of the largest contributors to both operating costs and greenhouse gas emissions, making hybrid technology an important pathway for decarbonisation.
Demand for critical minerals continues to grow due to the global energy transition, electric mobility and expansion of data centres, while major mining companies are targeting emission reductions of between 30% and 40% by 2030 and net-zero operations by 2050.
The mtu Series 4000 engines used in the hybrid platform have long been deployed in mining applications, powering equipment such as haul trucks, excavators, wheel loaders and drilling rigs across diesel-mechanical, diesel-electric and diesel-hydraulic configurations.
Rolls-Royce also highlighted that key variants of the Series 4000 engines are approved for use with HVO (hydrogenated vegetable oil), offering an additional route to lowering carbon emissions in mining operations.