Lead acid battery, lithium technology or fuel cell? If you want to work economically and effectively, you must determine the most suitable energy system for your specific transportation process. This decision depends on many factors and therefore requires a high degree of experience.
Energy is becoming more and more important in internal logistics. The EU hopes to achieve a climate neutral economy by 2050 at the latest - Germany even hopes to achieve this goal earlier. This means that carbon dioxide emissions must be avoided as much as possible or stored to the same extent as emissions. In order to achieve this goal, the European Commission and the federal states are currently using laws and regulations to oblige everyone to make their own contribution. For example, high carbon dioxide taxes, expensive emission certificates and a comprehensive ban on internal combustion engines will require electric drive for every type of vehicle from 2030 at the latest.
In addition, consumers are increasingly sensitive to the climate neutrality of services and products. For this reason, companies are increasingly ensuring that their supply chains meet the requirements of sustainable development. For example, suppliers must provide certificates on the origin of raw materials, production conditions and carbon footprint. Therefore, a good ecological balance table is increasingly becoming a competitive advantage.
Find the right energy system
In any case, the following applies to Europe as a whole: energy is valuable and becoming increasingly valuable - therefore, energy consumption and use must be managed intelligently. In internal logistics, this begins with selecting the appropriate energy system for the drive of industrial trucks. The current choice of fuel cell technology is lithium battery or lead-acid battery. But no matter which system you choose, this decision will have an impact. About the infrastructure of warehouse and production facilities, about the selection of transportation system, about the operating cost, and finally about the investment scale. Dyrk draenkow, product manager of energy systems, explained at a recent webinar hosted by still, an internal logistics company headquartered in Hamburg, Germany: "each of these energy systems has its own characteristics and requires certain preconditions in processing". He said that in order to reach a sustainable and cost-effective decision, the overall situation must be considered: the transportation process, the processing performance required, the type of forklift and, of course, the warehouse infrastructure.
Suitability criteria
According to BJ ? RN gr ü NKE, product manager of German energy systems, there are therefore five criteria that can be used to determine the system that best suits their respective requirements: Vehicle availability, consideration of infrastructure, acquisition and operating costs, and future safety. According to the expert, in this consideration, the overall result of lead-acid battery is quite mediocre. Although they perform mediocrely in terms of vehicle availability, they are completely unconvincing in terms of infrastructure due to their high requirements for storage space. On the other hand, when it comes to investment costs, they will stand out. Compared with all known energy systems, the purchase price of lead-acid batteries is very low, about 150 euros per kWh. However, this advantage is offset by the only medium efficiency operating cost of the system. When it comes to facing the future, this energy system can only partially convince still experts. "This technology has run out!" dyrk draenkow said. "No further development is expected, i.e. significantly reducing charging time or increasing power density. However, if we do not consider the above limitations, this type of battery will still be a reliable and very usable energy system in the coming years. It is especially suitable for users who only need to work for a few hours with a few cars.".
Lithium battery technology
Lithium batteries can be temporarily charged at any time - and in a very short time, without damaging the battery or shortening its life. This allows the vehicle to be used flexibly day and night without replacing the battery. Therefore, lithium technology ensures maximum availability, even in multi shift work. With regard to charging time, experience has shown that charging for one hour means driving for up to three hours. In addition, the infrastructure requirements of this energy system are very low. When it comes to investment costs, the situation is somewhat different. Because the purchase price of lithium battery is still about two to three times higher than that of lead-acid battery. "However, lithium batteries have at least twice the service life under the same capacity." BJ ? RN gr ü NKE said: "if you look at the overall price development of lithium batteries since 2010, the direction is clear: it is getting cheaper and cheaper. The system has also received scores in the future oriented field. Charging options and control options to improve efficiency are being further developed, while reducing the acquisition cost of the system.
Fuel cell system
The special feature of this energy system is that the power is generated in the car and no longer comes from the socket. "When we talk about fuel cells in internal logistics, we mean the so-called battery replacement module. This corresponds to a specific cell tank in terms of size, weight and shape. This means that existing lead-acid or lithium batteries can be replaced one-on-one with this module. In such a module, all the components required for the fuel cell are assembled," dyrk draenkow said. A so-called complete system first includes the fuel cell itself, the so-called stack. These devices convert the energy stored in hydrogen into electrical energy. This energy is used to charge the integrated lithium battery and provide continuous power for the vehicle. The system also includes a high-pressure hydrogen tank with filler neck and other components.
Since the system does not need to be charged but needs to be refuelled, it does not need to be idle on the charger or power socket for a period of time. It only takes two to three minutes at the hydrogenation station, and the vehicle can be used at full load again. This creates maximum flexibility in operating time, can meet demanding requirements, and can even carry out multi shift operation without restriction. Experience has shown that depending on the vehicle type and usage, the fuel tank can be used for 8 hours at a time.
However, the required hydrogen must be transported by tank truck. Alternatively, people can make themselves completely independent and produce hydrogen by themselves with their own electrolyzer. However, this requires additional power. If you don't want to emit any carbon dioxide, you can produce your own "green" energy: wind turbines or photovoltaic power. Since this involves a certain amount of effort, fuel cell technology can only be rated as moderately suitable in terms of infrastructure standards. This also applies to investment costs: on the one hand, a new "ready fuel cell" forklift must be purchased, on the other hand, there will be costs for the purchase of an appropriate fuel cell system. These costs are four to five times higher than the price of lead-acid batteries. The creation of the necessary infrastructure also still requires high investment, so it is almost impossible to economically use fuel cells for forklifts at present. However, funding schemes at the national and European levels are helping to make the business case "green" in the future economy. There are subsidies for vehicle equipment and infrastructure. Dyrk draenkow: "basically, economies of scale apply to the future of fuel cells: the more hydrogen consumers in the site, the faster the cost per kilogram of hydrogen can be reduced".
