Insufficient infrastructure, lengthy charging times and the high cost of electric batteries remain barriers to the widespread adoption of electric vehicles. But imagine if e-cars could be charged while on the move? That vision is getting closer each day thanks to a project initiated by the Technical University of Braunschweig in cooperation with a consortium of international commercial partners, including Volkswagen AG, Omexom GA Süd GmbH and Eurovia Teerbau GmbH.
The “eCharge” solution is based on the principle of inductive energy transfer – transmitter coils are embedded into sections of road and the charge is received by vehicles passing overhead. Prof. Michael Wistuba from the Institute of Road Engineering at the TU explains how it works in a : "The coils are installed at a depth of about ten centimetres. Power cables lead out of the road at a distance of 1.65 metres… into a so-called management unit, i.e. a control cabinet, at intervals of approx. 90 metres [on the kerbside]. These communicate with the vehicles via the coils and switch sections of the road on or off as required."
The TU’s inductive charging infrastructure has been in use since 2014 in the form of “Emil”, a wireless electric bus which serves the streets of Braunschweig. If the test module – which is being built at the German national road test facility near Cologne – is successful, the plan is to build electrified charging corridors of 25 kilometres at intervals along German motorways.
The institute is investigating the best installation methods and the most suitable construction materials to withstand overhead stress and weathering, while remaining low-maintenance. Meanwhile, another team is working on the development of a robust wireless billing process. The consortium has won EUR 1.9 million in funding from the German government.