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The Magazine
Christian Koch

Energy efficiency

Well charged – with reduced energy consumption

By installing an energy data management system a leading European supplier of medical and hygiene products identified the saving potential in the production area. The result was a reduced connected load by 10% in the charging stations for the forklifts and in the recycling area.

The product portfolio of the Hartmann Group includes everything from wound dressings for all phases of the healing process to customer-specific and operation-specific surgery sets. Absorbent incontinence products generate the largest sales volume, and the technological competence center for this segment is the factory in Herbrechtingen, Germany, located not far from the company’s headquarters in Heidenheim an der Brenz. Hartmann decided to implement an innovative energy data management system here in 2012 – and has already reduced connected load by 10%.

Among others recycling of raw materials turned out to be an area that could be turned off as needed without affecting productivity

Transparency is a prerequisite

Sustainability is very important at Hartmann. “The responsible use of resources is important to us, which is why we paid close attention to achieving the highest energy efficiency possible in our production facilities from the very beginning,” explains Christian Koch, technical director in Herbrechtingen. When energy costs rose significantly in recent years due to taxes and fiscal charges, the company decided to install a system to record the energy data in order to identify peak loads and uncover savings potential in the production area. Koch says: “The result surprised us. For example, we were able to see that a regular peak load was occurring at the end of each shift, which we were unable to explain at first. Using additional meters, we were able to identify the charging stations for the forklifts as the consumers. The last thing the employees do at the end of their shifts is connect the forklifts to the charging stations.” The remedy was obvious: the forklifts can be charged consecutively instead of simultaneously. However, the weaknesses of the existing system quickly became apparent in this process. It did not support the required load shedding control system.

Using additional meters, the charging stations for the forklifts could be identified as reason for peak loads

Automation system upgraded for energy management

Since WinCC powerrate is integrated into the familiar Simatic software environment, our company electricians had no difficulties with the configuration from the start.
Michael Mak, Energy Consultant, Paul Hartmann AG, Herbrechtingen

Power consumption is recorded at all relevant sub-distribution boards via Sentron PAC ampere meters. At the charging station, every charger is equipped with an ampere meter. The devices that are to be turned off are all connected to the corresponding Simatic controls in the same way via the ET 200M distributed I/O system. Identical energy management switch boxes make the overview easier. Load shedding is based on 15-minute trends. A prioritization system determines where a load may be shed if required. The strategy takes into account the magnitude of the expected peak load within the 15-minute interval, the load of the devices that can be shed and their priority, and their minimum on and off times. The switching characteristics can also be set to “rolling,” that is, devices are switched in the priority list on a rolling basis.

Sustainability pays off

The benefits have extended beyond just being able to reduce the peak load by 10%. Koch says: “Since we now have a very clear picture of the development of our consumption over time, we have a significantly better basis for future negotiations with our suppliers. We hope this will allow us to save even more.”

In addition, recording energy flows and evaluating them is a prerequisite for certification in accordance with ISO 50001, which attests to a facility’s efficient energy management. The factory in Herbrechtingen is already certified, and the Hartmann factory in Brück in Brandenburg, where WinCC powerrate is used to record energy data, has achieved a reduction in the Renewable Energy Sources Act levy due to this certification. Mak advises other factories that are preparing for certification. His experience: “There is savings potential everywhere. Nevertheless, it is difficult to transfer experiences from one production environment to another. The highest possible transparency is required. To be able to realize the identified potential quickly and efficiently, it makes sense to use an energy data management system that is integrated into the automation system. We have found that WinCC powerrate is very good in this respect.”

Since we now have a very clear picture of the development of our consumption over time, we have a significally better basis for future negotiations with our suppliers.
Christian Koch, Technical Director, Hartmann AG, Herbrechtingen
Picture credits: Wolfgang Geyer