Plant Equipment and Hire March 2018 | Page 48

PRODUCT FOCUS Hybrid machinery requires additional energy storage capacity compared to traditional machines, and the resultant change in powertrain configuration increases initial costs, with the potential for hybrid excavators to cost 20–50% more than their traditional counterparts (Wang et al., 2016). However, the potential reduction in operating costs, coupled with the decreasing cost of technology as it becomes more widely adopted, means that this differential is unlikely to remain so high, and also that owners can recoup the initial costs over the life of the machine. Volvo’s electric excavator One of the biggest innovators in the area of electric excavators is Volvo CE. In May 46 MARCH 2018 1 2 Concept excavators Volvo CE also has two electric concept excavators — the GaiaX compact excavator concept and the SfinX crawler excavator concept — developed as an exercise to examine what excavators of the future might be like. The fully electric, zero emission GaiaX — imagined for the year 2030 — is fitted with rechargeable batteries but can also be used while plugged in to an external electrical power source. Most applications can be carried out remotely using a transparent, augmented reality tablet computer, allowing the operator to dig and keep an eye on the surrounding environment at the same time. The tablet will be mapped with the city’s utility systems, showing the exact location of water pipes and electrical cables on screen, while a ground scanner provides precise information on obstacles to guarantee the effectiveness of auto-dig modes and projects images onto the ground to show the worksite and to mark safe zones for the operator and passers-by. The tablet will also connect to other machines in the fleet to provide a more effective way of working. The SfinX crawler excavator concept was developed by a team of industrial designers to answer the question, “What might a Volvo excavator of the 2020s look like?” The answer is something straight out of science fiction. With the central concept being a lightweight lattice boom, operator visibility is increased, while the reduced component weight improves efficiency, saves on steel, and reduces fuel consumption during operation. The machine has been designed with hydrogen fuel cells that convert a fuel’s energy into usable electricity and heat – without combustion. And all hydraulic systems could potentially be converted to electric motors. The removable cab also allows for remote operation, while the juncture between the undercarriage and superstructure would avoid the current arrangement of a large roller bearing by hovering on an electro-magnetic field, allowing zero friction and better control of the speed and torque turning of the superstructure. last year, the company unveiled its 100% electric compact excavator prototype, the EX2, a concept machine that delivers zero emissions, 10-times higher efficiency, 10-times lower noise levels, and reduced total cost of ownership compared to its conventional counterparts. Believed to be the world’s first fully electric compact excavator prototype, the EX2 is part of a research project and is not yet commercially available. The EX2 stemmed from the company’s earlier ELEXC research project, which ran from 2012 to 2015 and was partly financed by the French government as well as various funding bodies in France. Volvo CE worked with a team of six partner companies, which all contributed towards the EUR7-million project. 1&2: Imagined for the year 2030, the GaiaX is envisaged to be fully electric and capable of semi-automated remote operation through an augmented reality tablet device. the world’s first lithium ion battery-powered hybrid excavator: the 20t Stage IV/Tier 4-compliant SK210HLC-10. “Kobelco’s original hybrid technology has improved significantly since we first displayed our hybrid prototype at Intermat 2006 in Paris,” said Peter Stuijt, Kobelco product marketing manager. During swing acceleration, the swing motor is only powered by electricity accumulated in the lithium-ion battery, to save fuel. The braking energy generated during swing deceleration is converted into electricity, which is stored. According to Kobelco, the SK210HLC-10’s battery allows greater retention of stored electricity to provide the necessary electrical output to a Kobelco-developed 25kW power-assist generator motor. The SfinX concept excavator is already influencing today’s Volvo design.