Wireless charging is a solution which offers people an easy way to charge their electric vehicle. No need for wires, the driver only has to park properly so the pads can communicate and the process can be initiated by the charging system. The system also increases the safety for EV drivers because there are no exposed conductors.
On the downside, wireless charging has been criticised for its low efficiency, with electricity getting wasted during the charging process. Wireless charging also requires electric cars to have drive electronics and coils installed, increasing manufacturing complexity and cost. Finally, a charging infrastructure is needed, with dedicated parking spots for these vehicles.
However, newer approaches diminish the transfer losses with ultra thin coils, higher frequencies and optimised drive electronics, such as through the Magne Charge system using high-frequency induction to deliver high power at an efficiency of 86%.
CABLED (Coventry and Birmingham Low Emission Vehicle Demonstrators), a UK-project that is trialing at least 110 electric cars (plug-in hybrids, full electric and fuel cell) has added 2 wireless charge-capable electric, Citroën C1s.
The wireless system is provided by one of the key players in the wireless charging industry, HaloIPT, which use strongly coupled magnetic resonance to transfer energy from a power supply to a pick-up pad mounted on the vehicle.
In Italy, a fleet of 31 city buses equipped with special pads has been navigating the streets of Genoa and Turin since 2002. The buses are charged at the end of the route, where they change direction and stand for five to ten minutes – which allow drivers to keep buses in operation all day long.
From EV car racing to all EV drivers
The HaloIPT technology will also be conducted in motorsports, which is a good and easy platform to test and evaluate emerging methods such as wireless charging.
In partnership with Drayson Racing, the two companies will join efforts to install wireless charging pads in the pit lanes, and eventually, the actual surface of the race track. This system could enable constant charging from the circuit, allowing much lighter race cars to be built, with much smaller battery packs.
From-track charging is also relevant for all EV drivers. “Car manufacturers have already realised that if you don't have to plug a car in to charge it, it will significantly increase the adoption of the electric vehicles” said Eric Giller, CEO, Witricity, a US start-up business founded by MIT Professor Marin Soljačić, who has patented a new way to wirelessly transfer energy in much larger amounts and over greater distances than induction. Indeed, if the technology gets embedded into streets and motorways, EV drivers will never have to worry about charging again. However, expert forecasts see this technology going mainstream only in decades…