The Production Hall as a Passive-energy Building

It is not only in the area of products and solutions that Weidmüller strives to maximize energy efficiency and conserve resources. The electronics specialist from Detmold also focuses on sustainability in its own production processes, its building infrastructure, and in cross-sector technologies. The reason for this is that energy efficiency begins long before the electricity socket.

In doing this, Weidmüller is not just trying to keep up with the spirit of the times – it has been actively practicing energy and resource efficiency for four decades: “We are conscious of our obligation and responsibility toward future generations,” says the CEO, Dr. Peter Köhler. “This has influenced our business activities for many years on all levels, from the family of owners, the Executive Board and management through to our colleagues in administration and production.”

Weidmüller also sets high standards for sustainability in its own production. What began in the 1970s with noise protection measures in the stamping and assembly lines has since been systematically refined: heat recovery systems; integrated compressed air control systems; electronic ballasts; sophisticated environmental management, including structured waste separation; and much more have been standard at Weidmüller for many years. As early as the late 1990s, for example, Weidmüller installed a comprehensive building management system (BMS) in all production sites in Detmold, enabling needs-based and energy-efficient control of building facilities such as heating and ventilation systems. The company also established a technical energy management system (EnMS) for documenting energy flows and consumption (e.g., electricity, heat, cooling, and compressed air) at a very early stage – in 2009 – and has been systematically expanding it ever since. After all, consumption can only be optimized and minimized if accurate figures are available. This effort has proven to be very worthwhile: “Every step we take in the direction of energy efficiency in production has taught us a valuable lesson,” explains Köhler. “This knowledge and experience was taken into account when planning and constructing the new ‘Niemeierstraße’ production hall.”

The new production hall was designed without an independent heating system. “Waste heat from the production machines, compressors, and cooling systems is used to heat the building,” explains Helene Derksen-Riesen, Head of International Facility and Energy Management at Weidmüller. “In certain cases, for example when no production is taking place, the hall can be supplied by a neighboring building’s heating system.” The construction of the new production hall was planned on the basis of the latest version of the German Energy Conservation Ordinance (EnEV-2007) and completed in the spring of 2011. “Under the Energy Conservation Ordinance, the hall may consume 403 kWh of power per square meter per year. According to the energy certificate we were issued, it WEIDMÜLLER uses only 187 kWh / m2 per year,” says Derksen-Riesen. This is made possible by using additional modern construction materials, carefully coordinating the floor insulation and employing efficient lighting strips and insulated windows. In 2012, the additional use of waste water from the production machines, the compressor system and the cooling machine reduced the hall’s energy consumption to only 22 kWh / m2. “This means that it was more than 94 percent below the legally permissible level specified in the Energy Conservation Ordinance, which already sets very high efficiency standards. This measure alone saves 838 metric tons of CO2 every year,” explains Derksen-Riesen proudly. To put that in context: An average mid-range car emits some 2.6 metric tons of CO2 per year. The reduction in the production hall’s annual emissions is therefore equivalent to the amount of CO2 produced by some 320 mid-range cars in a year. “In addition, every autumn and spring an adjacent production and administration building is supplied with waste heat from the production machines,” Derksen-Riesen adds.

As well as using waste heat from the production machines, compressors, and cooling system, further steps have been taken to increase the production hall’s energy efficiency. In winter, the outdoor ramps for the forklift trucks and lorries are kept ice-free by using warm water from the heat recovery system – in the past, these systems ran on electricity, and consequently produced almost twice as much CO2 as today’s solution. To reduce losses in transformers and power lines, high-efficiency transformers were installed in direct proximity to the machines using the electricity. This allows the length of high-loss, low-voltage cables used to be shortened, in favor of more efficient medium-voltage cables, thus reducing consumption by a further three to five percent. As Derksen-Riesen says: “Modern, energy-efficient parts were used in all technical components we installed, including motors, pumps, ventilators, and lighting. Taken as a whole, the building’s electricity consumption is some 730,000 kWh – equivalent to 365 metric tons of CO2 – per year, which is less than that of a conventional structure with conventional installations.” The staff at Weidmüller are not the only ones to be proud of the company’s achievements. In the spring of 2013, the company was awarded the title of “Climate Protection Company” by the German Minister of Economics and Technology, Philipp Rösler, and the Minister for the Environment, Peter Altmaier. When it comes to energy efficiency, Weidmüller plans to stick to the course it has set: “At present, we are working on enhancing our ability to record the energy consumption of our production machines, right down to the tiniest level,” says Derksen-Riesen. “Our goal is to find out the consumption levels of individual machines, in order to make our processes even more energy-efficient in the future.” With this aim in mind, Weidmüller has developed and marketed its own measuring device, known as the Power Monitor, a tool that has already been used in the company’s own production lines with considerable success.

With a view to fostering sustainable dialogue, Weidmüller shares its knowledge, experience, and solutions with other companies, and has been active in various networks for many years. Weidmüller’s passive-energy production hall is the biggest individual energy-efficiency / climateprotection project generating the highest annual CO2 savings that the company has implemented so far. And yet, even this project is only one building block in the overriding sustainability strategy. “Weidmüller states explicitly that it does not view the hall as a flagship project; it is simply a part of the overall package of our sustainability strategy,” explains Köhler. “Although we used only high-efficiency components, these have already become standard technology. During the planning and implementation stages, we took care to ensure that all steps can be reproduced immediately.” In doing so, Weidmüller has created solutions that also help other companies to establish energy-efficient production systems, thus doubling its contribution to sustainability.