The charging of e-cars is to be revolutionised with inductive charging while driving. Researchers at the TU Braunschweig are investigating this in the "eCharge" project. However, the technology still seems to be a thing of the future - inductive charging is still in its infancy.
When deciding for or against an electric car, the lack of range and the inconvenience of charging often play a major role. The "eCharge" project at the TU Braunschweig is now researching inductive charging while driving to make charging with a power cable superfluous.
In the project, induction modules are being installed in the asphalt of 25-kilometre-long stretches of motorway. Alternating current flows in these modules, or coils, which generate a magnetic field. When an electric car with a corresponding charging structure drives over the asphalt, current flows and thus charges the battery of the electric car. The technology is expected to increase the range of the car by up to 20%.
The system would not make charging stations obsolete, but it would reduce the problem of charging during longer journeys. The technology would also be conceivable in car parks. BMW already introduced this system in 2018 with a so-called "ground pad".
But so far, the technology of inductive charging still has many problems.
One of these problems is the distance between the induction module, i.e. the coil in the ground, and the battery in the car. This distance must be precisely measured for charging to work. Similar to a smartphone that is charged without a cable, charging does not work in any position. Therefore, when parking, vehicles would first have to be brought into a precise parking position so that electricity can flow. When driving, the distance problem makes inductive charging even more difficult.
The power loss during wireless charging is also enormous. Only values from inductive charging of smartphones are known yet, but here the tried-and-tested method with a cable has a yield of about 75%, which is significantly higher than with inductive charging. Without a cable, a lot of energy is lost as heat, so that only about 60% of the current actually reaches the battery during optimal charging. If the smartphone is not placed exactly on the charging pad, only 40% of the energy is used. Whether the electricity was generated with renewable energy is of course just as important as when charging with a cable.
If the technology proves itself, the conversion of motorways and car parks would be a mammoth task. After all, the induction modules would have to be installed at regular intervals all over the country or even all over Europe with uniform technology to make driving with inductive charging a reality.
Nevertheless, the technology could be another step towards green mobility.