Japanese demo system that charges electric vehicles through their tyres

Scientists pass electricity through more than 10cm of concrete in latest step towards charging electric cars on the move.

Powering up the motorway may take on a whole new meaning now Japanese scientists have demonstrated a prototype for charging electric cars while they are on the move.

Researchers from the Toyohashi University of Technology successfully transmitted electricity to a pair of tyres through a 4in (10.16cm) thick concrete block at a trade show on wireless technologies in Yokohama last week.

In their demo the concrete blocks were placed under full-size car tyres to represent the road surface with metal plates in between. Between 50 and 60 watts of electricity was transmitted to the tyres, coupling to their steel belts and turning on an attached light bulb.

The researchers still have to overcome significant power loss – a similar experiment by the same team last year found around 20% of the electricity was lost in the circuit. While Takashi Ohira, an electrical engineering professor at the Toyohashi University of Technology, said the electric power needs to be increased by 100 times to actually charge a car's battery while it is running.

However, he said the components needed to augment the technology are cheaply available and insisted the system could even work through concrete double the thickness.

Wireless charging is edging closer to reality and a number of different systems have been pioneered in recent years.

Last year, mobile technologies company Qualcomm said it was looking to bring a trial to the streets of London in 2012 using an inductive power transfer system developed by Arup-backed New Zealand start-up HaloIPT.

The technology, which works in a similar way to an electric toothbrush charger, made its world debut in 2011 as part of the Coventry and Birmingham Low Emission Demonstrators (CABLED) consortium testing programme.

Source: BusinessGreen, July 9th, 2012