The depiction of a road with inductive charging systems. Credit: TU DelftThe depiction of a road with inductive charging systems. Credit: TU DelftThe number of electric cars in use is increasing exponentially in most developed countries. In the United States, federal and state incentives are a boon to the industry that has been selling plug-in vehicles at a very high rate.

In smaller countries, like the Netherlands, the “explosion” is bigger in comparison to the size of the population, and the need to provide charging stations is an important problem to solve. In 2017 there are 120,000 plug-in vehicles in the Netherlands, and by 2025 it is expected they will have over one million. This roughly represents 15% of all types of vehicles.

This is very commendable from the point of view of “preserving our planet.” However, without planning, this situation can bring chaos to the electric grid, the cost of energy, the beauty of the cities, and the comfort of its citizens. In advance of the time that this chaos may unravel, a team of researchers at the Delft Technical University (TU Delft) in the city of Delft, Netherlands, lead by Professor Pavol Bauer, are planning a good infrastructure for electric transport in the Netherlands.

"If 5 percent of one million cars start charging simultaneously, that would double the national peak power (30 gigawatts). This scenario is utterly unrealistic, our grid is not equipped for that" says Bauer. “While electric cars come ready-made from factories, the infrastructure to charge and drive them is up to us,” he argues. "One million electric cars also mean one million charging stations. Do we want to sacrifice our historic inner cities to endless rows of glowing blue pillars? I would find that inappropriate in city centres like Delft or Amsterdam. I would urge using inductive charging, which has no visual impact on the environment."

Inductive charging. This is the technology that transfers power wirelessly between two objects through electromagnetic induction. Bauer has been working on inductive charging stations since 2010. His proposed system consists of a coil embedded in the road that transfers power to cars above it. Bauer envisions using coils embedded in tiles as charging points to make charging infrastructures almost invisible. How about electric taxi lanes? For Bauer, a row of a few meters of inductive tiles can be the pavement where electric taxis charge while advancing to the head of the line. After a trip, When the electric taxi returns, it moves in the line row to start the next charge. “For autonomous cars, an inductive charging lane would also be ideal as the cars would not have to be left at set plug-in points,” Bauer says.

“Integrating electric vehicles into the power grid properly means using green current from solar and wind energy,” explains Bauer. “Only green electricity would reduce CO2 emissions to practically zero. Using mixed power, an electric car produces about half the carbon dioxide that a combustion car does. A test set-up in the lab simulates the charging of electric cars using the solar energy from a roof in an industrial estate. A smart multiplex system directs the solar power to each of the cars consecutively,” he adds.

Dynamic charging. Bauer and his team recommends intalling solar panels on the “highway of the future” in such a way that vehicles will not need to stop in order to charge. This is the concept of “dynamic charging.”