Technologies for the future
Hybrid drive
Hybrid drive is a combination of internal combustion engine and battery-driven electric drive systems. Hybrid technology offers one key advantage over straight internal-combustion engine propulsion:
Braking energy can be recovered for subsequent use when required. For this purpose, the truck requires an additional energy storage device: the battery. This allows zero-emission operation for limited periods, when operating in a closed factory space, for example. Fuel consumption is also commensurately lower. While Jungheinrich is continuing its research efforts on hybrid drive systems, in the present situation other optimisation approaches are seen as more effective avenues for reducing energy consumption.
Fuel cell
Fuel cell technology combines the advantages of a zero-emission electric motor with rapid refuelling capability. The truck is refuelled and ready for action again in a matter of minutes. Hydrogen storage and refuelling need to take place at high pressures, which currently involves high costs. The alternative energy carrier methanol, on the other hand, is no more difficult to handle than petrol or diesel.
Hydrogen generation and storage is an energy-intensive process, and the energy efficiency of a hydrogen fuel cell is currently well below that of a three-phase electric motor with a conventional battery. Jungheinrich is leading the material handling equipment sector in the development of direct methanol fuel cell technology. Our company is now working with the Jülich research centre to investigate possible applications in electric pallet trucks and electric pedestrian controlled trucks.
Lithium-ion energy storage units
Lithium-ion energy storage units are batteries that are no larger than lead batteries, but with double the service life and three times the storage capacity. They also have rapid charging capability, so that they can be recharged in around half an hour — virtually within the time of a lunch break — for an entire shift. The very small size of these batteries will allow far more compact structures and open the way to completely new truck design concepts. Jungheinrich's Concept 08 concept truck successfully combines this technology with direct drive systems. Direct drives are based on electric motors directly integrated in the wheels, eliminating the transmission system and providing outstanding mechanical efficiency.
This system provides energy savings of around 15 percent in comparison with conventional electrical trucks, and is clearly set to become one of the most energy-efficient drive systems of the future. Lithium-ion technology potentially opens up entire new areas of application for electric stackers, without the disadvantages of lead batteries. The automobile industry also sees the combination of this technology with high-efficiency electric motors as a promising future alternative to internal combustion engines.