Can electric excavators truly match the muscle of diesel?
Both customer pilot projects and in-house tests by Volvo Construction Equipment are confirming the comparable digging power of electric excavators to their diesel counterparts, with the added benefits of clean, quiet and comfortable operation.
The advantages of electric excavators are undeniable. They work quietly and without emissions, benefiting both operators and their colleagues on site, as well as the general public and the environment. For some construction professionals contemplating the shift from diesel to electric, however, a genuine concern emerges: do electric excavators possess the necessary power to effectively tackle the tasks at hand?
Contractors need machines they can trust to dig effectively in various environments, whether through dense clay or rocky terrain – and diesel engines are renowned for their high torque and robust power output, attributes crucial for heavy digging and challenging ground conditions. Moreover, even if an electric excavator does have the necessary force, another question lingers: will the significant energy required drain the battery quickly during demanding tasks?
Yet contractors need not fear. Through refined electric drive systems meticulously engineered to deliver heightened torque and power, Volvo Construction Equipment (Volvo CE) has designed electric excavators capable of matching the digging performance of their diesel counterparts. Furthermore, strides in battery technology have led to improved energy densities and enhanced charge and discharge rates, empowering electric excavators to sustain heavy workloads for prolonged periods.
EC18 Electric: Proven strength and endurance
Demonstrating their commitment, Volvo CE's emobility segment leader, Gustav Boberg, along with seasoned operator Benthe Combee, recently undertook a trench-digging test with the Volvo EC18 Electric compact excavator. They put this 1.8 t compact excavator through its paces on rocky ground at the company’s global headquarters in Eskilstuna, Sweden.
Benthe embarked on digging a 20 m long, 600 mm wide and 750 mm deep trench – a task typical for this type of machine – in hard, compact clay with about a quarter stone content. For the first 10 m, she operated the machine in ECO mode at 1,100 rpm, and for the subsequent 10 m, she ran it in ECO mode at 1,600 rpm.
The EC18 Electric performed admirably under these strenuous conditions. After an hour and 40 minutes of continuous operation, the machine proved efficient, consuming merely 5.6 kWh of energy – equivalent to 30% of the battery's capacity – despite the challenging application. The state of charge decreased modestly from 77% to 46% during this task.
EC230 Electric: Faster cycle times than diesel
At the larger end of the scale, the EC230 Electric, Volvo CE’s first mid-sized electric excavator demonstrated both its power and endurance during a customer pilot with Skanska on the Slakthusområdet urban development in Sweden. On this project, the EC230 Electric was tasked with excavating 75,000 t of rock and 96,000 t of soil in the initial stages, over approximately 2,700 working hours.
Powered by lithium-ion batteries, the 23 t electric excavator has been designed to accomplish a full eight hours of work, supported by a swift, high-power lunch-hour charge. On the Slakthusområdet project, the EC230 Electric has proven its mettle, working tirelessly all day long. Operators have attested to its equivalent digging power when compared to its diesel counterpart, and they've even noticed a swifter cycle time.
Richard Sjöblom, excavator operator for Skanska on the Slakthusområdet project, has been particularly positive about the ease of charging and the performance of the machine after testing it across different applications. He says: “If I had the choice of an electric or diesel machine in this size class, I would choose electric as there are so many advantages over a diesel machine. When the machine was delivered to site, there were many sceptics who thought the machine didn’t have the capacity to last the whole day, but they have all been proved wrong!”
So, can electric excavators genuinely rival the might of their diesel counterparts? Volvo CE unequivocally affirms that they indeed can – and continue to do so throughout a normal working shift.
Volvo excavators are sold and serviced in Great Britain through trusted dealer partner SMT GB. The range of electric excavators available from SMT GB includes the 1.8 t EC18 Electric and ECR18 Electric compact excavators, the 2.5 t ECR25 Electric compact excavator and the 23 t EC230 Electric crawler excavator – all backed by reliable and high-quality service support.