In addition, more and more systems that generate direct current are feeding into the increasingly decentralized electricity grid, above all photovoltaics. Up to 30 percent of energy is lost through the conversion between alternating current and direct current. If direct current were used consistently, two large lignite-fired power plants in Germany could be shut down and large amounts of CO2 emissions could be saved.

Industry plays an important role here. Initial pilot projects, for example in production cells in the automotive industry, show the potential of an energy supply with direct current, which could save up to 20 percent energy. Not only would conversion losses be eliminated, but direct current would also allow more energy to be fed into the grid or into energy storage systems when machines are slowed down. Lapp addressed the issue at an early stage and was the first company to investigate the question of whether conventional AC cables are just as suitable for direct current. Most experts have so far said yes.

The company wanted to find out more and started a research project in cooperation with Prof. Frank Berger from the Technical University of Ilmenau. Lapp is also supporting the working group with test cables and test benches. The tests show that the experts were wrong - the electrical field of a DC voltage has a different effect on the plastic insulation of a cable than an AC voltage field. Although it is still too early to make final recommendations, Prof. Berger emphasizes that "it is already becoming apparent that certain applications under direct current will actually require different materials than in alternating current applications." Further, application-oriented tests are to bring clarity, including in DC industry, a project funded by the German Federal Ministry for Economic Affairs and Energy, in which Lapp is participating as an associated partner.

Georg Stawowy, Chief Innovation and Technology Officer © Lapp

Lapp has been working on this topic for several years and last year launched the world's first series-produced cable specifically for DC applications: the Ölflex DC 100. Further Ölflex DC cables will follow at the Hannover Messe 2019, including a cable for controlling servo drives and a cable with TPE insulation that is particularly suitable for moving applications in energy chains - a choice that is also supported by the research results of Prof. Berger. "LAPP is a pioneer in the development of cables for low-voltage DC networks," emphasizes Georg Stawowy, Chief Technology and Innovation Officer at Lapp Holding. "LAPP customers can rely on the fact that our DC cables meet the same high quality standards as all Lapp products."