Published on March 28th, 2018 | by Tina Casey0
Batteries, Schmatteries: Wireless EV Charging Hits The Road
March 28th, 2018 by Tina Casey
Okay, so we know CleanTechnica has been down this road before, but now wireless EV charging on-the-go is looking more real than ever before. That’s right, you’re charging as you drive, or better yet, while your car is driving you. Come to think of it, mash up wireless EV charging on-the-go with self-driving cars and you have, well, a really long ride ahead of you.
Also, think about this: Bloomberg New Energy Finance is reporting that electric vehicles will cost less than gasmobiles in a few years because the cost of lithium-ion batteries is dropping super fast, and if you can wirelessly charge-on-the-go you will need smaller and even cheaper batteries, so put wireless EV charging together with self driving EVs that are way much more cheaper than gasmobiles and you have the future is now.
Wireless EV Charging Hits The Road
The latest electric vehicle development comes from the University of Colorado at Boulder. Here’s what assistant professor Khurram Afridi and the other researchers have been up to:
Over the last two years, Afridi and his colleagues have developed a proof of concept for wireless power transfer that transfers electrical energy through electric fields at very high frequencies.
Okay … so far so good. Proof of concept. Apparently we are not holding our breaths for that new self-driving Tesla Model Something that costs less than a Yugo and charges wirelessly while it ferries you around.
Will This Ever Really Happen Or Must You Always And Forever Stop To Charge Your Electric Vehicle?
Okay, so wireless EV charging on-the-go is still a pipe dream, but the UC-Boulder team has established a pathway forward. The problem is making the leap from stationary to movement, and the basic approach is to position a series of charging pads in the roadway, a few meters apart.
Here’s Professor Afridi with the concept:
“On a highway, you could have one lane dedicated to charging,” Afridi said, adding that a vehicle could simply travel in that lane when it needed an energy boost and could carry a smaller onboard battery as a result, reducing the overall cost of the vehicle.
Did you catch that thing about smaller onboard energy storage? Yes? No? Batteries account for a substantial portion of total EV costs, so smaller battery, cheaper EV.
To get their concept in motion, the Boulder team took the road less traveled so to speak. The conventional approach uses magnetic fields, which are easier to generate at scale than electric fields. The problem is:
However, magnetic fields travel in a looping pattern, requiring the use of fragile and lossy ferrites to keep the fields and the energy directed, resulting in an expensive system.
Dang! So, Afridi and the research team decided to focus on electrical fields.
That leads to another challenge:
The challenge of using electric fields for wireless power transfer – the capacitive approach – is that the large airgap between the roadway and the electric vehicle results in a very small capacitance through which the energy must be transferred.
So, what did they do? Why, the increased the frequency of the electric fields, of course.
In his laboratory, Afridi and his students set up a series of metal plates parallel to one another, with a gap of 12 centimeters between. The bottom layer would be the transmitter embedded in the road, and the top layer would be a receiver in a vehicle:
When Afridi flips a switch, energy is transmitted from the bottom plates. Instantly, the lightbulb above the top plates lights up—power transmission with no wires needed. The device has steadily improved to the point where it can transmit kilowatts of power at megahertz-scale frequencies.
Any bets on how far this will go? In one good sign, it’s an ARPA-E project, and last week Energy Secretary Rick Perry somehow convinced the budget-cutters in Congress to not just not cut, but to increase, funding for ARPA-E, even though President* Trump advocated for killing the whole program.
I know, right? Shocker! Well, maybe not so shocking if you’ve been following Perry’s antics over the past year. He’s been a steadfast supporter of Trump’s anti-climate, pro-fossil energy policy but more so in words than deeds, while aggressively promoting the nation’s renewable energy initiatives and our sprawling national lab system. In typical Perry style he’s been taking a victory lap around the labs in the days following passage of the new budget (heh — see for yourself, check into @ENERGY on Twitter).
Where were we? Oh, right. The research also has a National Science Foundation CAREER award under its belt and another grant from Colorado State University and the National Renewable Energy Laboratory.
Work in a warehouse? You might be the first to encounter one of these wireless EV charging systems:
In the near term, Afridi envisions the technology being adapted for warehouse use. Automated warehouse robots and forklifts, for example, could move along areas enabled for wireless power transfer and never need to be plugged in, eliminating downtime and increasing productivity.
Of Course There Had To Be An Elon Musk Angle In There Somewhere
Speaking of Tesla, Afridi foresees that the next step after warehouse and factory systems is a giant leap forward:
The technology could also be adapted for use in next-generation transportation projects like the Hyperloop, a proposed system that could take passengers from Los Angeles to San Francisco in 30 minutes.
Dream on, Klingon. No wait, Hyperloop might actually happen. And then there’s that thing about The Boring Company. The company’s founder Elon Musk (yes, that Elon Musk) recently pledged to prioritize mass transit for pedestrians and cyclists, but his concept for a commuter tunnel still includes a window for wireless EV charging on-the-go.
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*As of this writing.
Image (screenshot) via University of Colorado — Boulder.