STILL: Solve transport tasks with the lowest resource consumption

Lead-acid battery, lithium-ion technology or fuel cell? If you want to work economically and efficiently, you have to identify the energy system that is suitable for your respective transport processes. This decision depends on many factors and therefore requires a high level of experience. The intralogistics and energy experts from the Hamburg-based intralogistics provider STILL provided a comprehensive overview of the different energy systems during yesterday’s ‘Energy’ webinar, explaining the advantages and disadvantages of each system in a practical and clear manner.

The topic of energy is becoming increasingly important in intralogistics. The European Union wants to have a climate-neutral economy by 2050 at the latest – Germany even wants to achieve this goal much earlier. This means that CO2 emissions must be avoided as far as possible or stored to the same extent as they are emitted. In order to achieve this goal, the EU Commission and the federal states are now using laws and regulations to oblige everyone to make their contribution. For example, with a high CO2 tax, with expensive emission certificates and with the complete ban on combustion engines, which will make electric drive mandatory for every type of vehicle from 2030 at the latest.

In addition, consumers are also becoming increasingly sensitive to the climate neutrality of services and products. For this reason, too, companies are increasingly making sure that their supply chains meet sustainability requirements. For example, suppliers must provide certificates on the origin of raw materials, production conditions and the carbon footprint. A good ecological balance sheet is thus increasingly becoming a competitive advantage.

The search for the right energy system

In any case, the following applies throughout Europe: energy is precious and is becoming ever more precious – and therefore the consumption and use of energy must be managed intelligently. In intralogistics, this begins with the selection of the appropriate energy system for the drive of industrial trucks. The current choices are lead-acid batteries, lithium-ion technology or fuel cell systems. But no matter which system is chosen, this decision will have an impact. On the infrastructure of warehouses and production facilities, on the choice of transport systems, on operating costs and ultimately on the size of the investment. “Each of these energy systems has its own special features and requires certain prerequisites in handling,” explained Dyrk Draenkow, Product Manager for Energy Systems, during yesterday’s webinar. In order to arrive at a sustainable and economically efficient decision, he said, the big picture has to be considered: the transport processes, the desired handling performance, the type of vehicles and, of course, the infrastructure of the warehouse.

Suitability criteria

According to Björn Grünke, also Product Manager for Energy Systems, there are therefore five criteria that can be used to identify optimally suited systems for the respective requirements: vehicle availability, consideration of the infrastructure, acquisition and operating costs as well as future security. According to the expert, lead-acid batteries come to a rather moderate overall result in this consideration. While their performance in terms of vehicle availability is mediocre, they are not at all convincing in terms of infrastructure due to their high storage space requirements. On the other hand, they come out on top when it comes to investment costs. Compared to all known energy systems, the lead-acid battery has a very low purchase price of around 150 euros per kilowatt hour. However, this plus point is offset by the system’s only moderately efficient operating costs. And when it comes to future-proofing, this energy system can only partially convince the STILL experts. “This technology is exhausted. No further developments towards significantly shorter charging times or higher power density are to be expected,” said Dyrk Draenkow and added: “However, if we disregard the limitations described, this type of battery will remain a reliable and very usable energy system for the next few years. It is especially suitable for those users who only have a few vehicles to work with.”

Lithium-ion technology

Lithium-ion batteries can be temporarily charged at any time – and within a very short time, without damaging the battery or shortening its life. This allows the vehicle to be used flexibly, around the clock, without having to change the battery. Lithium-ion technology thus ensures maximum availability even in multi-shift operation. With regard to charging time, experience shows that charging for one hour means driving for up to three hours. Moreover, this energy system makes very few demands on the infrastructure. The situation is somewhat different when it comes to investment costs: Because lithium-ion batteries still have a purchase price that is about two to three times higher than lead-acid batteries. “However, lithium-ion batteries have at least twice the service life with the same capacity. If you look at the general price development of lithium-ion cells since 2010, the direction is clear: it is getting cheaper and cheaper,” says Björn Grünke. The system also scores points in the area of future-proofing. Charging options as well as control options for increasing efficiency are constantly being developed further, while at the same time reducing the acquisition costs for the system.

Fuel cell systems

What is special about this energy system is that the electricity is generated in the vehicle and no longer comes from the socket. Dyrk Draenkow: “When we talk about a fuel cell in intralogistics, we mean a so-called battery replacement module. This corresponds to a specific battery trough in terms of size, weight and shape. This means that an existing lead-acid or lithium-ion battery can be replaced one-to-one with this module. In such a module, all the components necessary for the fuel cell are assembled.” A so-called complete system first contains the fuel cell itself, the so-called stacks. These convert the energy stored in the hydrogen into electrical energy. This energy is used to charge the integrated lithium-ion battery, which supplies the vehicle with constant power. The system also includes a high-pressure hydrogen tank with filler neck and other components.

Since the system does not need to be recharged, but refuelled, there is no need for idle time at chargers or power outlets. After only two to three minutes at the hydrogen filling station, the vehicle is available again at full capacity. This creates maximum flexibility in terms of operating times and allows for heavy-duty use or even multi-shift operation without restrictions. Experience shows that a tank filling can allow up to eight hours of operation, depending on the vehicle type and use.

The hydrogen required, however, must be delivered by tanker truck. Or one can make oneself completely independent and produce the hydrogen oneself with one’s own electrolyser on the premises. However, this requires additional electricity. If you don’t want to emit CO2, you can produce the “green” energy yourself: with a wind turbine or photovoltaics. Since this involves a certain amount of effort, fuel cell technology can only be rated as moderately suitable in terms of the infrastructure criterion. This also applies to the investment costs: on the one hand, a “fuel cell ready” vehicle has to be newly purchased, and on the other hand, costs are incurred for the purchase of the appropriate fuel cell system. These costs are four to five times higher than the price of a lead-acid battery. High investments are also still required to create the necessary infrastructure, so that it is hardly possible at present to use fuel cells for vehicles economically. However, funding programmes at national and European level are helping to make the business case “green” in economic terms in the future. Subsidies are available both for the equipment of the vehicles and for the infrastructure. Dyrk Draenkow: “Basically, economies of scale apply to the future of the fuel cell: the more hydrogen consumers there are on the premises, the faster the costs per kilogram of hydrogen can be reduced.”

Conclusion

The efficiency of an energy system always depends on the particular application – unfortunately, there is no one system that fits all applications. Guidance in this very confusing situation is provided by the intralogistics and energy experts from the Hamburg-based intralogistics provider STILL, for example during yesterday’s webinar (www.still.de/webinar). But even beyond that, they are always on hand to offer advice and practical help to companies that are about to make an investment decision.

For more information, please visit: https://www.still.de/unternehmen/news-presse/news.html