Watch Those Kilowatts!

When the machines on the factory floor at the Homburg plant in Saarland boot up on a Monday morning, Fabian Bucksch can watch the process from the comfort of his office. One lamp after another lights up on his screen. Only a quick glance is needed to see if there are start-up problems anywhere. The machines stir from their deep sleep and kick into life – in standby mode, they consume just a fifth of the electricity they needed five years ago. “We have improved our management of the shutdown process enormously,” says the 24-year-old energy expert. This improvement can be partly attributed to the instructions given to employees on how to turn the machines on and off, but is also a result of some technical modifications. “These alone save the plant more than 1.2 million euros per year.”

The optimized shutdown management procedure is just one of many energy-saving measures that allowed energy consumption at the plant to be pushed down by almost eleven million euros. The measures were arrived at by means of the Energy Platform, software that provides full transparency on how much energy a machine is consuming at any given time. The platform allows a deep insight into plant machinery consumption patterns. “Upper and lower thresholds, as well as comparisons between machines, allow us to immediately identify which ones are using an excessively large amount of electricity and which ones are underutilized,” says Bucksch. Constant monitoring is not necessary: the platform sends a message to the relevant employee if any deviations occur.

The Energy Platform emerged as a “logical consequence”: “We started in 2007 with individual economizing measures, and then we gradually and systematically worked out how much potential there is,” says Bucksch who now, together with an energy team of 14 staff, is improving energy efficiency at the Homburg plant on an ongoing basis. The story behind this is that the amount of energy required to run the Homburg plant is huge. In order to assess consumption accurately and make the achievements visible, all machines were fitted with sensors. The measured data are processed in the Energy Platform and displayed in a clear structure.

This morning sees Bucksch and colleagues looking at the compressed air consumed by four new grinding machines. By comparing certain key figures, they realize that one of the machines needs more compressed air than the other. “This points to a leak somewhere,” says Bernhard Kohl from the Energy team. “Without the Energy Platform, we probably wouldn’t have located the leak until the next round of maintenance.” And the operators also find out something else about the condition of the machine. “From the key figures profile, we can also assess the state of the components in terms of wear,” explains Andreas Theis, Head of the Technical Functions department. As a result, the maintenance staff no longer changes components on a preventative basis after fixed time intervals. Instead, they implement a “predictive and current-status-based approach,” as Theis explains, “in order to reduce maintenance costs to a best-case minimum”. For maintenance staff, this alarm function is useful. If a spindle on a grinding machine needs to be replaced, the Energy Platform informs the staff in good time. “This saves us buying a new spindle and prevents quality defects and weeks of machine downtime.”

The Bosch subsidiary Energy and Building Solutions has been operating the platform since 2013 – and the Homburg plant is not just the first and largest customer, but also the inspiration and forerunner for other applications and innovations. “Use of the software by external customers also means that the Energy Team gets called in from Homburg,” explains Bucksch. “When asked to, we’ll even carry out technical modifications in our workshop.” At the Homburg plant, more than 15 percent of the 3,600 machines there are now hooked up to the platform. “Next, we want to link up our production with the plant’s energy control center,” says Bucksch. Using this data as a basis, load management could be improved. Bucksch provides an example: “On Monday mornings when all machines are starting up, this generates a peak load that our transmission system operators charge us lots of money for. If the platform can forecast this peak, then we can cap it by selectively controlling our energy supply.”

The company’s departmental heads are willing partners to the Energy Team. “A lot of companies haven’t even started looking at this issue yet,” remarks Arne Köngeter, Head of Production at Plant 1. The standard options of saving money by means of automation or staff cuts have largely been exhausted – while energy costs continue to rise. The staff at the plant has long since been made aware of all of this. Köngeter: “We always turn off the lights even when we leave the staff room.”