Hermes Fulfilment, a company that manages all logistics services along the supply chain for online retailers at its four own logistics centers, launched its sustainability initiative nearly a decade ago, seeking out areas where it could gain significant energy savings. As part of this program, the company decided to replace its conventional 400-volt technology with 24-volt drive technology, a move that has resulted in energy savings of about 25%.
Initial measurements have shown energy savings of about 25% thanks to the installation of the new drive technology. "We installed this technology in order to save energy," explains Michael Schekatz, head of the Technical Services Department at Hermes Fulfilment and responsible for sustainability. "At the same time, however, we noticed in trials how quiet it is. This is a success we never really expected and are quite pleased about. Furthermore, we have found that maintenance has become much easier now."
The technical service department of Hermes Fulfilment in Haldensleben, Germany, is upgrading the logistics center step by step during operation. But only four hours per day are available to do this. Thanks to the simplicity of configuring and wiring the conveyor control system, developed by Interroll Group, it can be installed and put into operation very quickly.
The system has a decentralized structure. The drives are installed in all of the individual conveyor zones. This means they can be switched on or off separately. Movement throughout the entire conveyor takes place only when goods are actually transported with zero pressure. Only those drives that are needed to transport the goods to be conveyed are actually driven, which offers the potential for energy savings and noise and wear reduction.
The logistics center in Haldensleben, with its approximately 133 acres of surface area, is the biggest and most modern site that Hermes Fulfilment operates. 170 million articles are moved there per year and up to 300,000 shipments leave the center every day. Approximately 1.2 million cartons are stored in two high-bay warehouses. The length of the conveyor line that all products are transported on is more than 18 miles (30 km) from goods receipt to goods issue.
The drives play an important role because they affect the energy consumption in conveying the products. In the field of modern logistics, the areas of material handling, storage and order-picking are often responsible for approximately 50% of the energy costs of plants with a high degree of automation. Heating, ventilation and lighting account for more than two thirds of the other 50%, and lighting for around 15%. This means internal logistics offers significant energy optimization potential.
Hermes Fulfilment started to think about the responsible use of energy early on. This pertains not only to the use of economical motors and controls, but also includes measures such as the use of back-fed braking energy in the high-bay warehouse, the construction of a combined heat and power plant in Haldensleben, and the use of energy-efficient lighting systems. A detailed cost-benefit analysis is developed for each project and includes not only the initial investment, but also the ongoing operating costs.
A scientific study conducted by the Institute for Material Handling and Logistics (IFL) at the Karlsruhe Institute of Technology (KIT), headed by Ing. Kai Furmans, confirms in many application examples the advantages that 24-volt drive technology offers compared to conventional 400-volt drive technology. The study is available on the Interroll Group website.