Stronger consumer demand could push car companies to take up wireless charging, but growth in EV demand is stymied in part by anxiety about public charging. — Bloomberg
San Francisco: Someday soon, plug-in cars may no longer need a plug.
Electric car drivers would simply pull into a specialised parking space when it’s time to power up, wait for a light on their dashboard to switch on, and then hop out of the car and go about their day.
This is the promise of wireless electric-vehicle (EV) charging, an inductive transfer of electrons that would eliminate the need for all those pesky cords.
Multiple startups have spent years working towards a world in which wireless charging goes mainstream, and as EV adoption picks up, momentum is building to make that dream a reality.
Companies are coalescing around standardised technology, automakers are embarking on wireless experiments, and municipalities are mapping out use cases. Even Tesla Inc is interested.
But major hurdles remain, chief among them slow charging speeds and the money and interest needed to build stations and get more carmakers on board.
While charging without a cord sounds great on paper, the technology faces the same paradox that’s impacting the rollout of public plugs: Stronger consumer demand could push car companies to take up wireless charging, but growth in EV demand is stymied in part by anxiety about public charging.
“If I was a car manufacturer, I’d probably be reluctant to put it on a vehicle today just because there’s not any wireless chargers out there,” says Michael Weismiller, programme manager for electrification research and development in the US Department of Energy’s Vehicle Technologies Office. “You really have to see the infrastructure and the vehicles get deployed at the same time for it to ultimately make sense.”
Wireless, or inductive, EV charging works by using magnetic resonance and a charging pad to generate a power-transmitting field.
When a coil in a receiver under the car aligns with a coil in the charging pad, the receiver captures that energy and feeds it to the car’s battery. The technology is similar to wireless phone charging, which also requires a receiver and aligned coils; but EV systems can work with up to 250mm of separation.
Speed is an issue, though. Most wireless chargers are on par with a Level 2 charger (the kind you’d use at home) and not the direct current fast chargers available at many public stations.
Electric cars also need to be designed with wireless charging in mind. While retrofitting EVs is doable, in practice it can void the car’s battery warranty, says Amaiya Khardenavis, an analyst at Wood Mackenzie.
For carmakers, enabling wireless charging is still difficult to justify: It’s expensive, and there aren’t yet charging stations to make it a compelling perk for car buyers.
Alex Gruzen, chief executive officer at Massachusetts-based WiTricity Corp, says his company’s wireless charging capability will cost automakers several hundred US dollars per car, and consumers at least US$2,500 to start – both figures he sees falling over the next five years.
These hurdles mean that, for now at least, wireless EV charging mostly exists in the form of pilot projects.
Some automakers in China and South Korea are testing the technology on new passenger cars, but many wireless-charging trials are geared at commercial vehicles, which tend to have consistent routes and the luxury of powering up overnight in fixed parking spaces.
“You can deploy the chargers at specific locations on the routes throughout the day,” says Loren McDonald, founder and chief executive of EVAdoption, an electric vehicle analyst firm.
This summer, WiTricity plans to roll out its Halo wireless system on E-Z-GO and ICON EV golf carts and light vehicles, after showcasing the technology on retrofitted vehicles like Ford’s Mustang Mach-E.
The company’s investors include Mitsubishi Corp and Siemens AG, and WiTricity has a partnership to demo wireless charging on cars made by South Korea’s KG Mobility. WiTricity says passenger cars get up to 56km of charge per hour with its technology.
“Charging remains one of the big points of anxiety for EV buyers, and we make it something that just happens in the background,” Gruzen says.
In Los Angeles County, the Antelope Valley Transit Authority uses inductive systems made by WAVE Charging to help power its fleet of electric buses.
The agency has 15 WAVE wireless charging stations – one at its offices and 14 across its bus routes – according to AVTA marketing director James Royal.
Using the 250-kilowatt chargers for just five minutes adds an average of 16km of range, says Benjamin Auslander, Wave’s vice-president of sales and marketing. “It allows for that bus to maintain its operations throughout the day without having to go back to a depot,” he says. — Bloomberg
