Providing clarity
Locally sourced food is a trend. Short transport distances guarantee freshness and help protect the environment. Marienhöher Direktvermarktung, based in Waldkirchen in the German Vogtland region, is profiting from this trend, which has enabled the company to continuously expand its production in recent years. In the past, it was difficult to determine how much energy each unit was using.
The farm has a herd of 700 cows and the direct marketing of its dairy and meat products have grown into profitable separate business units under one roof. Yet power consumption is a major cost factor, especially in the direct marketing of dairy, cheese, and meat products. But as managing director Heiko Hölzel emphasizes, saving at the expense of quality was out of the question: "That would be contrary to our tried-and-tested recipe for success." Measures previously adopted to conserve resources included operating a biomass power plant and using LEDs for the lighting of cattle sheds and production facilities. "We do, of course, know that further savings are possible but where is the best place to start?" This is the question that electrical engineer Ulrich Bauer asked himself. To answer it, Bauer first needed to know how much energy the existing systems were using.
Bauer decided to start by metering the\actual consumption at the central\power infeed. He found the SIMATIC S7-1200 controller and new Energy Meter module to be cost-efficient and easy to operate. The CPU 1212 was able to manage the planned tasks. The controller is available as a highly cost-efficient Starter Kit together with a KTP400 Basic Panel and the TIA Portal engineering software. The controller processes the consumption data recorded by the Energy Meter module and transmits them\to an easy-to-read display on the Basic Panel. The only additional items needed are current transformers for the three phases. The current, voltage, and power output data recorded on the panel can be sent to a PC for further analysis.
Detailed knowledge of the plant operations and load profiles of the exisiting machines and systems enabled Bauer to assign the consumption curves accordingly. "Monitoring overall consumption is the first step. But the results have certainly helped us in several different ways," Bauer comments. The capability to break down consumption data across the farming and direct marketing operations is just one aspect. Bauer says, "The most important finding was that the main circuit-breaking system of the plant, which has grown over the years, is now reaching its limits and urgently needs to be upgraded." An overload could lead to a refrigeration breakdown and the failure of individual system components. Bauer also discovered that the reactive power compensation was no longer up to the job. Although the proportion of reactive power is low, improved correction could nevertheless generate savings.
The recorded consumption data are currently analyzed on a monthly basis. The analysis of plant operations alone has enabled the company to already achieve significant savings. Hölzel comments: "If we can show staff how\much energy a running pump uses unnecessarily, they pay far more attention to avoiding waste consumption. The certainty of being able to achieve energy savings has the advantage that it motivates workers to use resources responsibly far more so than any other general plea."
The opportunities offered by the new technology have sparked Bauer's interest in implementing additonal energy management measures. In order to further increase transparency in power consumption, he is planning to improve the consumption metering with additional Energy Meter modules. In the long term, he is considering installing switching systems to avoid consumption spikes. The use of SIMATIC controllers and the Energy Meter offers the ideal basis for further expansion. The SIMATIC S7-1200 with the CPU 1214 or higher, for example, enables the connection of eight Energy Meter modules (two modules can be connected to the CPU 1212). Consumption data can additionally, or alternatively, be displayed via the web server integrated into the controller. This means users can read power consumption figures from the office at any time. A particularly interesting feature is that diagnostic messages can be analyzed on the same PC for maintenance purposes. All that is required is an Ethernet connection to the in-house network or an Internet connection to enable remote access.
The high level of interest we have received in this solution has shown us that using the SIMATIC controller can also be beneficial in applications with minimal automation requirements.Christoph Bauer, Marienhöher Direktvermarktung
Siemens offers the program to connect the Energy Meter to the SIMATIC S7-1200 controller in order to view consumption data on the Basic Panel as a free-to-download application example. The application was programmed by Christoph Bauer in collaboration with Siemens Industry Online Support, optimized based on the experience gained at Marienhöher Direktvermarktung, and documented in such a way that even users with no programming skills can get a similar application up and running in just a few hours. "The high level of interest we have received in this solution has shown us that using the SIMATIC controller can also be beneficial in applications with minimal automation requirements. Automated energy data metering also provides transparency regarding the energy consumption of older plants that have been expanded over time. Furthermore, the solution is so easy to integrate that hardly any PLC expertise is required," explains Christoph Bauer.
Note on industrial security:
Appropriate security measures (e.g., network segmentation) must be taken to ensure secure operation of the system. Find out more about industrial security.
