Why Wireless

The future is wireless

Nearly all charging today is done by plugging your car into a charger with a cable. It works, but it could be so much better. We think wireless charging is to electric vehicles what a remote control is to a TV. Better, easier, simpler – it takes the hassle out of charging.  

That’s why Electric Green is on a mission to make wireless charging infrastructure as cost effective as possible so everyone can benefit from it. 

How does wireless charging work? 

Instead of transferring power to the vehicle battery via a cable, wireless systems use induction charging to achieve the same thing. High-frequency alternating current (AC) current is supplied to a groundpad (primary coil) which produces a magnetic field. This is picked up by a carpad (secondary coil) located on the underside of the vehicle. This magnetic field is then converted to direct current (DC) and fed into the vehicle battery.    

Importantly, wireless charging is virtually as efficient as plug-in charging when measured from grid to vehicle.   

The table below shows some of the comparisons between the two charging methods.

Plug-in

  • Requires heavy cables, which need storing in the vehicles, get wet, dirty, driven over, and damaged
  • Exposes drivers to the risk of accidents when walking around vehicles to plug-in, especially in fleet depots
  • Is often linked singularly (2 at most) to charging equipment meaning there is lots of unsightly street clutter and trip hazards
  • At risk of vandalism as tethered cables on higher powered chargers are being stolen for their metal content
  • Difficult to use for those with physical disabilities

Wireless

  • Cable-free, meaning no dirty cables that break and cause trip hazards
  • Extremely convenient and easy to use, therefore accelerating EV adoption rate
  • Promotes engagement in Vehicle to Grid (V2G) connectivity as the vehicle can participate even when it’s not charging
  • Safer for the driver, as there is no need to exit the vehicle or wait in areas that are often poorly lit
  • Accessible for all drivers as charging can be initiated without leaving the vehicle  
  • Suitable for multiple locations, such as taxi ranks, when vehicles are only stationary for short periods  
  • Really the only viable solution for autonomous vehicles when there is no driver to plug-in 

So why isn’t wireless charging used in more places?

A major question is that with all these wireless charging benefits, why hasn’t it become more widespread? One answer is that wireless charging takes place at a frequency of 85kHz – that’s 1700 times higher than the grid in most places. It’s very difficult to send this high frequency electricity over long distance without significant voltage drop, so many companies struggle to deliver a scaleable, cost-effective version of wireless charging infrastructure.

That’s until the Electric Green solution came along…