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Sustainability in plant engineering
"That's why we are constantly working to further increase energy efficiency in robotics and plant engineering."
15 December 2022
Reading Time: 4 min.
By Tamara Sindel
Energy efficiency and sustainability are among the most pressing tasks of our time. In industry, too. We spoke with Christoph Steinherr, Developer Controls, about how KUKA implements energy efficiency measures in plant engineering. He also provides an outlook on the potential of DC grids, which could revolutionize energy saving in industry in the future.
Christoph, you are working on solutions to save energy in plant engineering: Where does KUKA come in here?
Christoph Steinherr: We already pay attention to energy efficiency in the planning and engineering of new plants: industrial robots, robot control and programming are optimized so that as little energy as possible is consumed while maintaining short cycle times. The location of the plant and how the cycle times are regulated also play a role here - the better the location and the more optimized the cycle times, the lower the energy consumption, e.g. through short robot travel distances.
I.e. in the energy consumption of a plant it depends on each component...
Christoph Steinherr: Exactly. That is why KUKA robots are optimized in their transmission components and efficient motors are installed. The mechanical design of the robots is compact, and where weight can be saved, it is.
What about existing facilities?
Even in existing plants, we are able to subsequently use energy more efficiently by analyzing and optimizing robot paths without increasing cycle times.
Energy savings should be possible on a much larger scale in the future, keyword: direct current...
Christoph Steinherr: KUKA recognized some time ago the enormous potential of a transition from alternating current (AC) networks to large-scale direct current (DC) operation in industrial manufacturing. This not only saves a considerable amount of copper: DC also offers, among many other potentials, the possibility of feeding braking energy back into the power grid and reusing it. This brings a huge advantage.
In today's production environments, AC power consumers are hardly ever used...
Christoph Steinherr: Correct, because converters for robots and other motors through to LED lighting and the 24 V circuits are already based on DC technology today. Thus, by using direct current uniformly across the board, energy that would otherwise be lost when converting alternating current to direct current can be saved. Incidentally, this is also advantageous when renewable energies are fed in from photovoltaic or wind plants that are based on direct current.
How then can the energy "gained" by switching to direct current be used?
Christoph Steinherr: Recovered braking energy or yields, for example from PV systems, can be stored in low-loss storage units in DC grids if they are not needed immediately. When needed, this energy can then be used, reducing peak loads in the grid. These storages also supply the required energy during AC grid failures, so that the plant can continue to operate self-sufficiently. Temporary downtimes in the production plant can thus be prevented and major financial losses for the operator can be avoided.
Sounds like DC is a good thing in terms of energy efficiency. Is the technology here ready yet?
Christoph Steinherr: For about three years, KUKA has been part of the "DC-INDUSTRIE2" research program sponsored by the German Federal Ministry of Economics and Climate Protection, where it is working with 38 other partners on the potential and implementation of direct current. For this purpose, KUKA converted an existing cell in the SmartProduction Center at the Augsburg site to direct current. This allowed measurements to be recorded and compared before and after the conversion. The stability of the direct current network could also be tested.
What results did you come to?
Christoph Steinherr: After three years of intensive development, DC-INDUSTRIE2 and its partners were able to develop a DC concept that meets the requirements for safety and reliability. It was also important to us to back up the immense potential of a switch to direct current, such as energy efficiency and reliability, with figures. We were able to demonstrate this with numerous measurements and tests. To make it easier for DC technology to enter the market, further DC standards must be incorporated into the world of standards and more DC-compatible devices must be available as standard.
The outlook for the coming years already shows a growing number of DC components, which will give a further boost to the spread of DC networks.
In the next few years, DC grids can really take off
The industry presumably plays a key role here?
Christoph Steinherr: Of course, industry has an important role to play here. We as a company are also aware of the responsibility: An efficient and sustainably planned plant influences the Co2 consumption of our customers over the entire value creation in production. At the same time, it increases the cost-effectiveness of production and saves raw materials. That is why we are constantly working to further increase energy efficiency in robotics and plant engineering.