Home / Blog / Charge as you go

Charge as you go

An electric bus. Nothing new but for the fact of being able to recharge its batteries from the road. A special road, actually, that can release energy via inductive coupling. Image credit: Swedish Transport Administration

The big issue when you have an EV car is using it on a long trip. As long as you stay within your home vicinity there is really no problem. Recharging your car battery is actually easier than stopping for a gas refuelling. You just park your car and plug it in the mains. Actually, some cars may be recharged simply by being parked in the garage through induction: you lay a recharging mat that is always connected to the mains and your car as a receiving antenna under its chassis. That’s it. Like recharging your electric toothbrush, you “park it” on its holster and it gets recharged!

Laying the induction plates under an highway tarmac in Sweden. Image credit: ElectReon

The Swedish company ElectReon thinks that what can be don in your garage should also be possible on highways. It is clearly much more expensive but the result should be the same: car, buses, trucks driving on the highway can recharge as they go.

So far they are testing the system on a very short (1.4 km) stretch of road. If all goes well the plan calls for the electrification of 2,000km of highways in Sweden by 2030, as a step to make the Country carbon neutral by 2045.

The first trials have shown the capability to transfer 70KW from the electrified road to a truck driving at 80kmh. Now it is time to run the test on an electric bus and later to cars. Notice that as the vehicle gets smaller, so the induction area shrinks and the power decreases. It will take a bit of trials to find the best arrangement for the induction plates to optimise the energy transfer.

Also, it should be noticed that the whole is quite expensive since you have to remove the tarmac to place the induction plates and then lay it on again. There are issues of durability of tarmac laid on the plates and the potential creation of fissures around the plates. In other words, the way to go is still bumpy.

In parallel, ElectReon is testing the possibility to deploy induction chargers on bus lanes in a city or at bus stops. Here the lay out may be different, taking into consideration the lower speed of the buses in a city environment. Equipping bus stopping areas with induction plates would be even cheaper (smaller area to cover) and more effective (the bus stand still in a very specific space and the recharging efficiency is better) however it remains to be seen if the short stopping time is suffincient to provide a significant recharge.

As you can see it is not easy and there is a lot that needs to be experimented. Nice to see that researchers and Governments are exploring many ways for a greener future!

About Roberto Saracco

Roberto Saracco fell in love with technology and its implications long time ago. His background is in math and computer science. Until April 2017 he led the EIT Digital Italian Node and then was head of the Industrial Doctoral School of EIT Digital up to September 2018. Previously, up to December 2011 he was the Director of the Telecom Italia Future Centre in Venice, looking at the interplay of technology evolution, economics and society. At the turn of the century he led a World Bank-Infodev project to stimulate entrepreneurship in Latin America. He is a senior member of IEEE where he leads the New Initiative Committee and co-chairs the Digital Reality Initiative. He is a member of the IEEE in 2050 Ad Hoc Committee. He teaches a Master course on Technology Forecasting and Market impact at the University of Trento. He has published over 100 papers in journals and magazines and 14 books.