WiTricity started as an idea at the Massachusetts Institute of Technology (MIT) in the early 2000s, introduced by physics professor Marin Soljačić. He started researching the idea of how you could move power over distances efficiently after his wife's cell phone kept beeping overnight, as it was low on battery and she forgot to plug it in. This spawned a unique concept: an entirely efficient resonator that would keep oscillating once energised. Through this, Soljačić was able to move power from one resonator to the other without having to couple them at different distances. Effectively, the only energy that came off the source resonator was the energy absorbed into the receiving resonator. After the idea was patented in 2005, a team of fellow professors and grad students conducted the first experimental demonstration in 2007, shocking the world. In the same year, WiTricity was formed which, over the last ten years, has focused on evolving the technology and moving into a number of different market segments.
WiTricity CEO Alex Gruzen brings me up to date by telling me the benefits of wireless charging electric vehicles in future urban ecosystems and what has to be done to improve people's lives. “The broadest visibility we have had is what we are doing with EVs,” he says. “We are directly working with eight of the top ten global automakers and their tier 1 suppliers, whilst setting a standard for wireless charging with the Society of Automotive Engineers (SAE).” The SAE is a pioneering global association and standards developing organisation for engineering professions in various industries, driving new technology and innovation. Recently, the association voted on the future of a global standard for future wireless charging, selecting WiTricity’s core electricity architecture as the benchmark. “We are really seeing the whole market accelerate now that there is a standard and all of the automakers are rallying around it. The first cars using this technology are already starting to make the rounds for press tours,” Gruzen explains.
Over the last couple of years, we have seen a growing number of businesses trying to get into the emerging EV segment and it seems that, although we have companies like WiTricity who have been around for over a decade, it is only now that the bulk of businesses have actively shown a focus on this technology. “What's fascinating for me, is how it is creating a major shake up within the traditional structure of how automakers operate,” Gruzen adds. “Now they are thinking of themselves as mobility companies instead of carmakers and it is changing the way that they contemplate new technology within their products.” Thanks to this change, innovative startups like WiTricity are now building relationships with global automakers, which has only really been achievable over the last few years.
Gruzen tells me that, for the most part, automakers only dealt directly with companies like Continental and Delphi which have been involved in the industry as long as themselves. “These companies are having to engage with young, innovative startups that have the next generation of new technologies, either bringing it in-house directly or directing tier one suppliers to incorporate the technology.” For example, WiTricity is working with General Motors and its Chevrolet Bolt, has a strong relationship with Nissan and has been backed by Toyota from very early on. “This shows the shift in how technology gets adopted. We are now selling systems directly to automakers which bring them into their labs to understand the capability, we model different shapes and sizes for vehicles and allow them to direct their tier one suppliers to take the technology licence from us so that they can build it. This is our business model,” Gruzen explains.
In a typical urban settlement, the average city dweller lives in a block of flats without any space in front of the property that can host an EV charging station. This is a major issue that needs to be overcome if cities want to build a mobility ecosystem that the public can benefit from. Wireless charging is the solution for this, as it does not have to use as much space as EV charging stations. Guzen tells me that wireless charging can be built into the existing infrastructure, however there will still be a lack of space in dense areas like world cities. To solve this, Gruzen believes that we will start to see wireless charging hubs, that will couple with autonomous software in order to create an efficient environment for future mobility to thrive. “One way to think about this is contention for charging, which comes back to our vision that, just like all of the vehicles that will have self parking software in the future, you will be able to have these cars shuttle themselves to wireless charging points positioned around the area. However, there is still a finite amount of space, which means that we will start to see shared usage of these charging points among multiple cars of a common charging source,” he says. “The problem with plug-in chargers is that you come in from work at 5:00 pm, plug in your car and you are then tied into that point till the next morning. We believe that wireless charging combined with some degree of autonomy is a future element in dealing with this contention.”
The issue with this innovation is that this will not come to life until there is a sufficient number - whatever that may be - of EVs on the road. WiTricity has predicted a phased roll-out of the technology, starting out with one-to-one wireless charging in which you buy a car and install a wireless charger in your garage or driveway. “Now that the standard has been set, our conversations with infrastructure players have begun, so there can be planning over things like shared wireless charging for flats and offices. By around 2023, we will start to see the deployment of autonomous vehicles which will continue to progress the EV ecosystem,” Gruzen forecasts.
He also believes that between 2025-2030 we will start to see wireless charging lanes throughout our cities - the final step in smart infrastructure that would eliminate range anxiety through an efficient and convenient system. “What is significant about our technology architecture is that nothing would have to change on the car to make this possible,” Gruzen continues. “From a technology roadmap and vision, you could imagine renewable energy-powered lanes that don't have to tie to the grid and could be delivering power to vehicles in transit. We have been working on this from an architecture point of view.”
Now, more than ever, we are seeing a range of vehicles that come in all shapes and sizes, from large SUVs to low-clearance sports cars. Although you would expect this to be a challenge for wireless charging, having different ground clearances for the regulators to link, WiTricity’s charging technology can deliver power at a distance through a common ground assembly. Working with the SAE, a standard has been defined so that the assembly can power cars that are Z1 (sports car), Z2 (sedan) and Z3 (SUV), all at different height ranges. “You may require a larger receiver resonator within the vehicle, however the ground assembly never changes and the efficiency and the power delivery doesn’t change at all,” adds Gruzen. “Of course, the slightly larger cars need a larger receiver, but they have the space for it and physics works in our favour.” The same ground assembly, which can be built into different surfaces such as concrete, can support up to 25 cm of ground height depending upon which resonator size the vehicle has. This allows the infrastructure to be introduced on a much larger scale than plug-in rivals.
A lot of people think that wireless charging is less efficient than a physical charger, although this is not the case. Gruzen claims that the wireless charging architecture is as efficient as plugging in the car, which people cannot seem to wrap their heads around. “We deliver 91-93% end-to-end efficiency from the grid, all the way to the battery of the car. If you were to measure a typical plug-in, you would get between 80-93%, with the majority in the high 80s,” he says. “People think that plug-ins must be 100% efficient but we are as - if not more - efficient than this. The reason for this is that, because of the architecture, WiTricity doesn’t need to use a DC to DC converter as it uses resonator coils to adapt the voltage to what is needed by the battery at any point in time.
Now, thanks to WiTricity, people are realising that wireless charging is the most simple and straightforward step for e-mobility. “We have developed this technology over many years and, now, we have reached that crossover point where the capabilities of the technology are aligned with the automaker demand. We will continue to push this technology forward as battery efficiency and capacity increases,” Gruzen assures. Over the next three years, we will see almost all of the world's top automakers with wireless charging capability, playing a part of what Gruzen refers to as the “holy trinity of mobility.” Through this new age, e-mobility, autonomous vehicles and car sharing will all complement each other on the path to future transportation, and this must be supported from the ground up.