FORKLIFT DRIVE SYSTEMS – BETWEEN THE HYPE AND REALITY heart of research and development. This applies especially to inhouse, battery powered warehouse vehicles. Multi-shift operation with a single battery charge, avoiding battery replacement and simply reducing battery sizes have immediate cost implications for our customers. Energy recovery in braking and load lowering, efficient AC threephase drive systems and state-of-the-art charging technologies have long been standard at Jungheinrich, developed over many years. With IC motor trucks fuel costs account for over one third of total costs. With its latest hydrostatic truck generation (keyword: stateof-the-art TDI motors) Jungheinrich is again one step ahead of the competition. This has been borne out time and again in independent comparative tests. As a result we offer a product range that is already extremely attractive from a carbon footprint perspective.
The search for alternative drive systems is nothing new: back in 1900 Ferdinand Porsche introduced the electric Lohner Porsche with wheel hub motors, followed in 1902 by a hybrid vehicle. Faced with rising oil prices, tight budgets and concerning environmental developments, manufacturers of forklift trucks are coming up with ever more efficient and environmentally friendly drive systems, both IC motor and electric. But which systems best meet the customer’s requirements? Back in 1900 Ferdinand Porsche launched the highly regarded
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electric Lohner Porsche with wheel hub motors at the World Exhibition in Paris. A racing version followed and by 1902 there was even a hybrid vehicle. Public interest is focused on alternative drive technologies depending on oil prices. A hype cycle represents phases of public receptiveness to new technologies. Due to the climate debate and rising energy costs we are now in a cycle of maximum receptiveness to alternative drive systems. With lift trucks however, drive technologies and energy efficiency for optimum customer intralogistics solutions have always been at the
MATERIALS HANDLING AND TRANSPORTATION
The choice of drive system technologies depends on the customer New drive systems must always be judged by how much they improve customer advantage. And customer requirements are becoming increasingly complex. They include above all • • • • •
Energy efficiency, Low / zero emissions Short fuel times, High capacities, A positive carbon footprint and above all, • A low total cost of ownership And this is where the wheat is separated from the chaff in the drive systems currently being debated. Although hybrid and fuel cell systems meet the criteria for
Lithium-ion technology is becoming an alternative to lead acid batteries The combination of lithium-ion technology with efficient electric motors can therefore be used initially in smaller vehicles. However, with appropriate investment it could increasingly be used with larger vehicles as an economic alternative to the traditional lead acid accumulator. At the moment we cannot accurately predict when this will be. It depends largely on developments in the automotive industry. short fuelling/charging times and improve the carbon footprint, in terms of total cost of ownership these technologies are simply uneconomical for customers. In the foreseeable future fuel cell technology is unlikely to make the leap to economic efficiency, despite rising energy costs. Energy costs will continue to rise as new technologies decrease in cost. This applies in particular to lithiumion batteries, should these gain a foothold in the automotive industry in future. If costs fall significantly as a result of automated production, lithium ion batteries could fully exploit their advantages over lead acid batteries. • Three times the storage capacity with the same weight, • Higher currents and hence performance for the same size, • Better efficiency for the same charge and discharge performance, • Shorter charging times, • Considerably higher number of charge/discharge cycles, • Greater use of capacity - lead acid batteries are generally only 80% discharged by the time the voltage fails, • Reducing the useful life significantly.
But what about the much-debated hybrid drive system in industrial trucks? A factual assessment of this not exactly new technology requires the right comparisons to be made. If you compare outmoded technology from a previous generation with the latest hybrid technology, there is indeed a reduction in consumption in excess of 40%. It is misleading to publish such figures. If you compare Jungheinrich’s latest generation of energy-efficient trucks with hybrid technology, the potential for a reduction in consumption through hybrid systems reduces drastically. It’s the same with the car industry. Modern diesel vehicles have virtually the same consumption levels as hybrids. If you factor in the additional technical cost, the carbon footprint equation may even be negative. According to Marek Scheithauer, Head of Product Management for IC motor trucks at Jungheinrich’s Moosburg plant, there are only a small range of applications where the hybrid systems can be used effectively. The additional technology required is only worthwhile on highly intensive operations and even then only if diesel and LPG prices increase by a further 50%.
Conclusion: Electric mobility and hybrid technology have been around for over 100 years. Fuel cell technology has also been known for decades and was used back in the 60s as an energy source for the Apollo missions. The real challenge lies in developing the technology specifically to optimise costs taking into account all application factors. The automotive industry must play its role The time is right to introduce a new technology when its application advantages outweigh those of the old technology. Wide-ranging public interest in new drive technologies should not distract our attention from the main focus. According to a VDMA study, over the next ten years 56% of efficiency improvements will come from existing technologies. In addition lithium-ion technology has great prospects for finding its way into industrial trucks. Not least, the industrial truck sector is dependent on the support of the automotive industry to force through the enormous amount of investment required for cost-effective battery production. Jungheinrich will continue to actively develop alternative drive technologies without losing its focus for improving existing technologies. This will allows us to provide trucks that meet criteria for efficiency and a good carbon footprint. When the opportunity arises to achieve a greater customer advantage through lithium-ion or hybrid technology, Jungheinrich will offer its customers these trucks. by Peter Dibbern
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