Last month saw the Society of Automotive Engineers (SAE) select a circular coil design to become the standard all automakers must use for wirelessly powered EVs – called SAE J2954. The decision effectively crowned WiTricity the heir to the automotive wireless charging throne, if there is going to be one. The coronation was properly marked this week by a new licensing partnership with the manufacturer of the world’s best-selling electric vehicle – Nissan.
Back in 2006 a bunch of MIT researchers believed that by adding magnetic resonance to the equation of wireless charging, they could improve the range of wireless charging. They were correct and quickly moved to monetize the discovery. Their company, WiTricity, holds the foundational patents for resonant wireless power transfer, with over 165 issued patents and over 200 pending patent applications – and provides 3.7kW, 7.7kW, and 11kW reference designs for the J2954 taskforce.
Standard wireless charging technology requires the transmitter and receiver to be in close contact and in perfect spatial alignment – with devices like phones needing to be placed on charging mats in the correct orientation to pick up the charge. WiTricity’s magnetic resonant charging allows power transfer over distance with greater spatial freedom, allowing multiple devices to be charged simultaneously – through surfaces at different power levels.
Companies in wireless charging unwilling to license WiTricity’s magnetic resonance technology, have notably released charging surfaces for cellular handsets, televisions and laptops. But the limitation of close contact and then need to be spatially aligned for power transfer to take place, have rendered standard wireless charging an impractical approach for vehicle charging. WiTricity, with the SAE endorsement, looks like it will wear the crown of wireless charging, but the size of the future kingdom is still up for discussion.
To date EV owners wanting to avoid the onerous task of plugging-in their vehicle have the option of purchasing an aftermarket wireless charging system from a company like Pluglesspower – the price of installation for a Tesla Model S is $4,120. When tested by the Idaho National Laboratory in 2013, the Pluglesspower chargers were found to deliver power at 84%-90% efficiency.
In comparison, WiTricity states its charging system to be around 91 percent to 94 percent efficient. According to WiTricity these levels can be even more efficient than plugging in because it doesn’t need certain pieces of technology, like an AC-to-DC converter. Notably, that’s a big efficiency advantage for Witricity, but we couldn’t find any results from the same lab to validate its claims.
WiTricity doesn’t offer aftermarket products. The company licenses its technology to Tier 1 suppliers like Delphi, IHI and TDK who build products for automakers. At the same time, WiTricity also works with the automakers directly, including Nissan, Toyota and GM, to improve its technology. The latest deal with Nissan is notable, but getting an idea of the potential future scale of this market is rather difficult.
The first vehicle integrated charging system isn’t planned to come to market until 2018, with the Mercedes-Benz s550e plug-in hybrid luxury sedan. Rethink has not confirmed it, but believes Brusa, a Swiss Tier 1 manufacturer, was responsible for the development of the charger. Brusa has licensing agreements with WiTricity, Qualcomm Technologies and a supply relationship with Mercedes.
The Qualcomm Technologies partnership is significant because it acquired New Zealand’s Halo IPT in 2011, a company that held significant technical patents in wireless charging. Qualcomm has since been further developing and licensing its Halo wireless technology – but only seems to have won-over Mercedes-Benz, to date.
So is wireless charging confined to the luxury vehicle market, as a premium feature? Unsurprisingly, WiTricity CEO Alex Gruzen disagrees with this sentiment, saying that he believes wireless charging will allow vehicles to be fully driverless – enabling them to refuel on their own. For Gurzen, “there just aren’t going to be fleets of autonomous Ubers without wireless charging.”
Speaking of Uber, the ride-sharing firm announced a 20-vehicle trial in London, in partnership with Nissan and its Leaf EVs. Uber also has a partnership with Toyota, for its Prius and also Lexus vehicles, and given Uber’s determination to remove its human drivers from the ride-sharing equation, the company looks set to be making a lot of early plays in the autonomous recharging sector.
The wireless technology would be put to use in parking spaces or depots, allowing a fleet of autonomous EVs to top-up their batteries when needed – coordinated by a central platform that is able to ensure there are always enough vehicles on the road to meet the expected demand.
Consequently, a technology like WiTricity’s allows the car to simple park in the correct location, and doesn’t require Tesla’s uncanny robo-arm or a human worker to plug the car in to a charging station – a boon to a company like Uber that is focused on streamlining the autonomous process as much as possible.