Nikolai Tesla – the creator of Alternating Current and inspiration for the name of the pioneering electric vehicle (EV) company – caused himself to move from a controversial but ultimately still respected inventor to the prototypical ‘mad scientist’ with a single idea: wireless electricity.
Tesla believed that the wires that were proliferating across the world since he and Thomas Edison’s famous ‘voltage wars’ could be replaced by vast towers that would transmit electrical energy to homes for hundreds of miles around.
Tesla’s vision didn’t come to pass in his lifetime, but it has inspired the technology behind induction cookers and wireless charging. These don’t live up to Tesla’s aspirations, and it’s possible that nothing could: induction cooking can only heat and wireless charging like that in the Qi charging pad can only work up to about four centimetres (though wireless charging range may improve).
A version of the technology that currently allows phones to charge wirelessly is also being developed for EVs – after all, they work from the same Lithium-ion batteries. The technology has a few hurdles to cross before it enters mass usage, but it could become the future standard at public charging points, in homes and businesses and maybe someday on roads themselves. Let’s explore this in more detail…
Wireless EV charging works with exactly the same technology as wireless phone charging: magnetic resonance is used to transfer energy from a charging pad to a dinner-plate sized receiver built into the vehicle. However, it goes without saying that not all current EVs are going to be compatible with this charging shift until the technology is standardised. Much as it has with Qi charging for mobile phones we may see a situation similar to the early days of EVs, when Type 1, Type 2 CHAdeMO and other types of charging plugs made charging difficult.
The Korean car manufacturer, Genesis, and Swedish company Volvo, currently have the most mature wireless charging schemes, and they are indicative of where the technology is heading. The Volvo pilot scheme uses XC40 vehicles as part of a three year test of the technology, which can charge up to 40kW, while the Genesis trial uses a more modest 11kW. Charging the 40 kWh battery in a Nissan Leaf (which gives the vehicle 270km of range) would therefore take one hour in Volvo’s wireless charging pad and a little under four hours with Genesis’. These are better times than can be achieved by the 3.6kW charge from a standard wall socket, but are nowhere near the 100kW and 350kW charging times that are possible and increasingly common in wired charging.
Can it be made faster? According to industry experts (quoted in this McKinsey article), the chokepoint isn’t the charging pad itself, but the vehicle’s battery management system. Hypothetically, it could be upgraded to allow much faster charging speeds, and this would be crucial to not just compete with wired chargers, but to enable one of the key advantages of wireless charging. Whereas with wired charging, drivers need to plug chargers in and use a terminal to start charging, with wireless charging they can charge whenever they are parked. This is ideal for short charges, which are more effective with faster chargers. A driver could stop to grab a snack and add fifty miles of range to their vehicle if they stopped at a 350kW charger.
Since they are wireless, their operation is likely to be wireless too. Instead of having to use a terminal as you currently do when using a wired charger, wireless chargers could interface directly with a vehicle through wireless technology to pay for the charging. If, as mentioned above, wireless charging is likely to be done in short bursts rather than long stretches, this would be very useful.
There are a couple of challenges with wireless charging that may prevent it from gaining traction – in the short term at least.
The first is that the infrastructure for wired charging is getting more advanced, with 43,626 public charging points in the UK (at the time of writing) and many more chargepoints at private businesses and residences. The UK government, private businesses and individuals have invested an inestimable amount in the technology that we have now, to the point that not being able to find charging is no longer the same concern it was a few years ago in the UK. Tearing out all of the existing chargers to be replaced with a new technology that can only be used on a smaller number of vehicles is not feasible. Especially as, even though we’ve made strides, we’re still, as an industry, getting the current infrastructure to a stage where EVs can truly compete with the traditional ease of refuelling ICE vehicles at petrol pumps.
This brings us to the second factor that could provide a challenge to the adoption of wireless charging. It may not be possible to upgrade many of the 810,000 electric vehicles on the UK’s roads to use wireless charging, so new vehicles will need to come onto the market that have wireless charging technology. This creates a negative feedback loop with wireless charging pads: there’s no reason to build them while vehicles can’t use them, and there is no reason to upgrade vehicles while there is no charging infrastructure available.
It could be argued that wireless charging offers too many advantages over wired charging to not be adopted – the key question is when. We might start seeing the first EVs with wireless charging on the market soon, given that major companies like Volvo and Genesis are trialling the technology, and once that begins to happen, we could then start to see the first wireless charging pads.
That is the future, but it shouldn’t take away from the now. Companies across the UK are at very different stages of their fleet transition. Clearly the benefits of EVs are so extensive that there is every reason to transition now particularly as technology and infrastructure are already rapidly improving in the run up to the 2030 cut-off for the sale of new petrol and diesel vehicles, and beyond. My advice to all business stakeholders is to stay on top of developments so they can react quickly to changing scenarios in mobility and make informed decisions during the transition.