Wireless charging has the potential to transform the EV experience, but it has its detractors. Alex Gruzen of WiTricity, a wireless charging technology company, addresses five common questions about the technology.
Interest in electric vehicles continues to grow, but there is still consumer concern about the availability of chargers and the inconvenience of plugging in. Wireless charging for EVs offers a convenience factor that may be hard to believe – especially when you consider the average consumer’s experience with personal devices like phones and earbuds. Exact positioning on charging pads for these devices can be finicky. How can we possibly rely on wireless charging for something so big and important as our transportation?
The truth is, the technology underpinning wireless charging for EVs is based on magnetic resonance, which is proven to enable power transfers from ground charging pad to any type of vehicle. Wireless EV charging is not unpredictable, and it’s not just novelty – it will be a reality in our future mobility ecosystem that is not only electric but autonomous and shared. It’s time to set the record straight and bust a few myths about wireless EV charging.
Is wireless EV charging as efficient, or as fast, as plug-in options?
Wireless EV charging via magnetic resonance technology delivers the same power, efficiency levels and charge speeds as conventional plug-in charging methods, with no compromises. Charging can be done through water, snow, ice, concrete, granite – you name it – with no concerns about cable connections. Most Level 1 or 2 consumer plug-in EV chargers operate in the 88% to 95% efficiency range end-to-end, from grid to the battery. Leading wireless EV charging technologies today operate in that same range, at 90% to 93% efficiency.
Doesn’t the vehicle must be parked in just the right positioning for power to transfer? Isn’t that inconvenient?
Magnetic resonance does not require physical contact or accurate alignment. This is critical, especially in scenarios where it might be difficult to park a car exactly right, or where it might be difficult to physically view the charging pad, because of snow, for instance. Furthermore, automakers are developing interfaces that indicate to the driver, or direct the self-driving car, that the car is aligned within the target position range for power transfer to occur. It’s much easier than most think and can happen transparently. Just park and charge, it’s that simple.
Doesn’t wireless EV charging present a safety risk?
A common misconception about magnetic resonance technology is that it’s not safe. Perhaps because these systems can deliver energy over mid-range distances, consumers assume they’re being exposed to potentially dangerous electromagnetic fields. In reality, EV wireless charging technology is safe and meets all regulatory guidelines for human safety.Designed after years of rigorous and detailed electromagnetic analysis, and tested by the Society of Automotive Engineers (SAE), wireless charging technology keeps stray magnetic and electric fields below the well-established and longstanding safety limits used in all electromagnetic consumer devices — including cellphones, wireless routers, Bluetooth headsets, induction cooktops and radio transmitters. Further, proprietary sensing and processing hardware and software ensure safety and ease of use. These auxillary systems include detection of foreign objects, living objects and position detection to ease parking alignment.
Wireless EV charging sounds nice to have, but is there more to it than that?
Wireless EV charging presents so much more opportunity than just convenience. First, the future of mobility is autonomous, and self-driving vehicles need wireless charging, as there will be no driver to plug them in. The electrification of fleets and car-sharing requires that the cars are always plugged in, fully charged and ready, yet fleet operators are already seeing issues with drivers remembering to plug in, significantly impacting vehicle availability and return on investment. Wireless charging solves that issue, as charging automatically beging upon parking.
Finally, wireless charging also makes always-available bi-directional charging possible. Making EVs available as local on-demand energy storage is critical as utility companies look for an increased mix of renewables in the electrical grid. Bi-directional charging, otherwise known as vehicle-to-grid (V2G) technology, can help utilities handle increasing peak demand. For V2G to work seamlessly, the cars need to always be available on demand, and the reality is that most owners don’t plug in when their battery is well-charged. Wireless V2G solves that as whenever the vehicles are parked, that stored power is available, and provides a new source of value for the EV owner. Through all these new use cases, wireless charging will shift from being “nice to have” to being a “must have.”
As automakers aren’t prioritizing wireless EV charging, isn’t it years away from entering my home?
All automakers are looking for solutions that will help break the adoption barrier for EVs. Many drivers cite the inconveniences of EV charging and range anxiety as the primary reasons for not switching to electric. Wireless technology, however, would surely make EV charging more attractive than refueling. The majority of global automakers are actively working to integrate wireless charging into their EV roadmaps. Several automakers are currently presenting concept vehicles (Hyundai’s new Kona, Porsche’s Mission E and Audi’s e-tron SUV) with wireless integration, or even bringing them to market (BMW’s 530e).
Further, industry groups including SAE International (global), IEC/ISO (global), and CATARC (China) are bringing forward industry standards to ensure full interoperability. In this way, wireless charging does not meet the same fate as plug-in chargers, in that automakers and regions have different types of plugs, are drivers often have difficulty finding one that works.
The boom in EVs is just beginning, with some analysts expecting the number of EVs for sale in the U.S. to grow from 16 models currently to as many as 80 by 2022. Wireless charging is the future, and will play a significant part in making EV ownership appealing to all.
Alex Gruzen is Chief Executive Officer of WiTricity, a technology company which develops wireless power transfer solutions using patented technology.