The system, which incorporates electric and autonomous Volvo machines, will run in a real production environment for 10 weeks. Benefits expected include an anticipated 95% reduction in carbon emissions and 25% reduction in total cost of operations.
The research project, dubbed Electric Site, aims to electrify each transport stage in a quarry – from excavation to primary crushing, and transport to secondary crushing – although a negligible amount of diesel power will still be used.
Gunnar Hagman, CEO of Skanska Sweden, said: “This is the first time that anything like this has been attempted in the quarrying industry and, if successful, Electric Site could serve as a blueprint for transforming the efficiency, safety and environmental impact of quarries around the world.”
The project has involved developing new concept machines, work methods and site management systems that together form a complete site solution. New technology encompasses machine and fleet control systems and logistic solutions for electric machines in quarries. The system technologies are not currently available for sale, but will inform future product development.
Three rigid haulers, for example, have been replaced by eight smaller prototype HX2 autonomous, battery-electric load carriers to transport the material from the primary mobile crusher up to the secondary static crusher. This protoype has advanced significantly since the HX1 proof-of-concept vehicle was first shown to customers and members of the international press at the Volvo Exploration Forum in September 2016. It now incorporates Volvo Group components such as electric motors, batteries and power electronics, including a new drivetrain, and a new feature of a vision system.
The primary crusher on the Skanska site is loaded by the 70t dual-powered, cable-connected EX1 excavator prototype, which had not previously been seen by customers and press. The base machine for the EX1 is a Volvo EC750 model that has been upgraded to incorporate an electric motor in addition to the diesel engine. If the cable is connected, the machine will automatically start in electric mode. If it’s not, it will start in diesel mode.
The piles of material on the site are organised by the LX1, Volvo CE’s prototype electric hybrid wheel loader. The machine can deliver up to a 50% improvement in fuel efficiency, as well as significant reductions in emissions and noise pollution compared to its conventional counterparts, claims Volvo. The LX1 is a ‘series hybrid’ that incorporates a driveline that consists of electric drive motors mounted at the wheels, electric-driven hydraulics, an energy storage system, a significantly smaller diesel engine and new machine architecture, including a new design of the lifting unit. It is this combination that enables the substantial gain in fuel efficiency. The prototype – which has 98% new parts and a fundamentally new machine design – can do the work of a wheel loader that is one size larger.