Tesla CEO Elon Musk likes to do things differently, but ironically his latest demonstration of a seemingly futuristic robotic “snake” is a way to stick with tradition – wires and plugs – when others are going wireless.

He is extremely busy however, and if he doesn’t know, he wouldn’t be the only one unaware that Momentum Dynamics can send industrial-strength current through the air as efficiently and cost-effectively as a Supercharger.

That is, says the company, any power level up to 135 kilowatts of electric car charging energy and beyond is technically feasible today with no cords to break, trip over, or freeze, as the case may be. This technology is already being developed, and can work for all sorts of charging applications down to home systems.

Perhaps Musk might want to take note, as he clearly demonstrates Tesla still has needs. Beyond new Superchargers filling in maps around the globe, the bizarre and possibly complicated “snake” was devised just to fill a need – automatic charging.

The “snake” represents one potential way to recharge a Model S hands free. It could dovetail with autonomous parking functions believed pending, but could wireless charging complement Tesla’s existing solutions and do the same function as a robotic arm, only better?

Yes, according to John M. Miller, PE, PhD, formerly the Director of Power Electronics and Electric Power Systems Center at Oak Ridge National Laboratory (ORNL).

Miller, a technical adviser for Momentum since May 2014, is one of the top authorities on high-power Wireless Power Transmission (WPT). Last month he published a technical paper in Transactions on Transportation Electrification, a journal of the Institute of Electrical and Electronics Engineers (IEEE).


In short, the paper, full of complex equations and tech-speak, says Momentum’s technology is ready for prime time.

What is its technology? It’s an improvement on an old concept – resonant magnetic induction. One receiver weighing 30-50 pounds installed flush on the bottom of a vehicle could handle anything from level 1, 2, or Supercharger-class level 3.

Before ORNL, Miller was a research engineer with Ford Motor Company’s electric and hybrid vehicle programs. His long resume has led him into being an advocate for WPT and he says he joined Momentum Dynamics in part because of its progress beyond others also venturing in the field.

Fig. 1. Functional diagram of a wireless charging F1:1 installation, PFC = Power Factor Corrector; BMS = Battery Management System. Source: IEEE.

Fig. 1. Functional diagram of a wireless charging F1:1 installation, PFC = Power Factor Corrector; BMS = Battery Management System. Source: IEEE.

“I believe wireless charging is the future, and I also believe Momentum’s technology is the most cost-effective and safest,” said Miller.

Wireless can be embedded in the pavement or sit on the surface and offers several benefits, said Miller. The system has no moving parts to engineer like a complex robotic plug-in-contraption, thus nothing to be damaged, tampered with, or stolen.


WPT could also enable vehicles to charge on the fly, and Miller envisions potential for them to be located all over the place, including in home garages or in driveways; in public parking spaces – for many commercial and passenger vehicles, including Teslas.

Plug-in infrastructure can also do this, but wireless could be embedded in the roadway, and experiments in this functionality are ongoing – including in the UK later this year.

Readily available fast charging could also mean the search for the elusive higher energy density battery technology breakthrough becomes less pressing. Tesla is already working with what it has today constructing the Gigafactory, and beyond that Nevada battery plant to create economies of scale, wireless could mean less energy storage is needed.

This in turn could save vehicle costs and weight.

Opportunity charging could be even at stop lights, noted Miller, along streets or on highways at rest stops, lay-bys, shopping malls and so on.

Momentum’s tech also works in all weather, under snow, slush and ice, and the car would be equipped to get within proximity, perform a virtual “hand shake” — and be as hands-free as a robotic plug-in device might be.

Efficiency would be on par with a plug Miller said. The wireless portion has demonstrated 91-percent efficiency and Momentum is shooting for 93 percent. On-board chargers (OBC) have similar efficiency at handling current delivered by traditional plug-in electric vehicle service equipment (EVSE), said Miller. So, while the solid cord connection is more-efficient at delivering current to the OBC, losses elsewhere in the power processing and routing make what EVs now rely on no better than Momentum’s setup.

Momentum Dynamics has previously shown less-powerful wireless charging for cars like the Nissan Leaf and Chevy Volt, but the company is at work on systems for commercial vehicles with higher power requirements than a Model S.

This is why it’s confident it can be done.

Are You Skeptical?

If so, you are not alone. We shared this with a Silicon Valley techie who writes for this site occasionally. Despite his extensive knowledge, he fired off a typical knee-jerk response

“One question is: what happens to small animals like cats if they snuggle up on the warm charging pad during cool evenings when charging at 135 kW wirelessly? One wonders,” he asked.

The answer is Momentum Dynamics’ wireless technology conforms to international magnetic emission standards, poses no known risk to human or animal health, and actually, the human body is 40-times less visible to it than the best optical glass is to sunlight.

The high current goes where it's supposed to go and does not threaten the iPhone or the hand holding it.

The high current goes where it’s supposed to go and does not threaten the iPhone or the hand holding it.

This and answers to other more-pointed critical inquiries have been batted down so far by Momentum, which has invited many from near and far to come see live proof.

Momentum is also working with at least one major car manufacturer and we were privy to see a demonstration. The system we were shown was being prepped to be sent to the OEM for testing. If they like it, they may use it, or they may ask for changes in the prototype; this is part of the process and business as usual.

SEE ALSO: Momentum Dynamics Says Wireless Electric Car Charging Is Ready Now

This system was delimited to around 28 kilowatts – not Supercharger strength, but more than a Nissan Leaf’s 6.6 kilowatts, or the standard 10-20 kilowatt on-board charger of a Tesla Model S.

We’ve also seen an electric truck from one of the world’s largest shippers at Momentum’s laboratory. It may have more news on this and other behind-the-scenes work later this year.

The secrecy is at clients’ request, not Momentum’s, and its CEO Andy Daga, an engineer who’s done work for NASA agreed with Miller the system can be scaled to Tesla levels.

Q & A with Andy Daga

We asked Daga about the hypothetical wireless Supercharger idea, Momentum is working first on smaller systems, but he said if there were a will at Tesla, there is a way at his company.

Daga (right) and engineer Bruce Long who developed patented technology for Momentum.

Daga (right) and engineer Bruce Long who developed patented technology for Momentum.

“A more powerful 50-kilowatt or 100-kilowatt charger is certainly feasible and would almost certainly cost no more than a Supercharger, since many of the basic power electronics are similar,” said Daga who added beyond-135 kilowatt power is just as feasible. “The wireless charger would have lower lifecycle costs, however, because there would be no cord or plug to be damaged or vandalized.”

But a Supercharger is only possible where utilities will supply that much 480-volt three phase current, and Daga said a home system would be possible, but obviously limited to power on hand.

“A single-phase, 240-volt, 50-amp circuit in a home represents the [typical] maximum power transfer, which with a necessary safety factor, is about 10 kW. Unless alternative arrangements are made with the local utility to provide more power, this constrains the time it takes to charge at home,” said Daga. “Without making allowances for battery equalization time, a rough order of magnitude approximation for bulk charging 70 kilowatt-hours of battery capacity would be at least 7 hours, assuming no interruptions.”

A second line at the house or higher power service could make it possible to charge faster, Daga added.

To actually make a Tesla compatible, the automaker would have to cooperate.


Momentum is not willing to try and hack into the Model S and adapt its system. It has modified a Chevy Volt and other vehicles for lower power demonstrations, but manufacturer collaboration is otherwise needed.

Tesla however is working on the snake, although Daga and Miller say it looks potentially more pricey than a wireless system would be.

We asked what cost hurdles Momentum would face compared to what Tesla is now doing with its plug-in level-two systems.

“There are essentially no cost hurdles to delivering a 25 kilowatt Tesla-compatible charger to the market,” said Daga. “These would be ideal charging stations for Teslas who park in office buildings or supermarkets, and could easily augment the existing plug-in charger currently built into the Model S and future Tesla vehicles.

“It would certainly cost less to add wireless charging than to buy, install, and maintain a robotic arm,” he said, adding “There really are no major technical barriers in front of us. Safe power transfer has been accomplished, what remains is vehicle integration and industry standard organization.”


So, what would have to happen to implement wireless?

“Charging a Tesla Model S is a straightforward technical proposition. This is a business decision, not a technical hurdle,” said Daga, adding Tesla owners from around the world have contacted Momentum requesting wireless charging. People in places like Norway where freezing cords are a real problem particularly said the need to go beyond physical plugs and cords is there.

“It’s pretty clear the business case is strong as we have seen in the a attempts by Volkswagen and Tesla to develop a robotic conductive charger. Now that – a robotic charger – is a technical and cost challenge,” Daga said.

We asked do you see Tesla going to wireless charging as likely?

“Yes, I would say it is inevitable,” said Daga speaking generally, not necessarily Tesla deciding to do business with his company specifically. “The business case is undeniable. Let’s just say that I do not believe Tesla will be the last company standing when every other automaker has fielded wireless charging.”

We asked whether he could elaborate on this “inevitable” shift, as he sees it.

“The timing of ‘inevitable’ will in large part be driven by Tesla’s competitors who are developing BEVs and strong PHEVs. More than one is trying to develop a head-on competitor to the Model S,” said Daga. “All of the major automakers are committing to wireless charging; they are either developing 3.3-kilowatt inductive chargers internally, or they are working with suppliers, including Momentum, to develop these for them; we are concentrated on units that are sufficiently versatile to operate throughout the power range of 1 to 50 kilowatts.”

Daga added lower power devices from 25-50 kilowatts power would likely come before 135-kw Superchargers, assuming they ever did. It would not be an either/or proposition, either, but complementary to the existing network of plugs.

But Tesla is of course occupied with building a Gigafactory, launching Model X, developing Model 3, growing its global operations. It has found time to develop a robotic arm which Musk tweeted last year was coming.


But wireless is on its way too, so we asked Daga about that.

“Many automakers are trialling systems now on their proving grounds. My estimation of the first adoption of an OEM production wireless charger, albeit for a low power (3.3 kilowatt) device, will be 2017, but I am not privy to all of the work going on in various labs,” he said. “High power wireless charging is also in concurrent trials, and it will hit the market very soon after. High power will eventually win this contest, with low power being the easiest pathway to a first introduction, but high power being the only pathway to treating the real needs of a growing population of EVs.”


What else can be added to the discussion?

“The world is moving rapidly to a new technical paradigm where autonomous operations and wireless transmission of both data and power are influencing product designers and consumer expectations in every realm. It cuts across the spectrum from factory floors, to inside the distribution centers of Amazon and FedEx, to the end-user products that we all use,” said Daga. “The hottest area of innovation today is happening in the two areas which were each regarded for many decades as being the most resistant to innovation: electrical utilities and automotive technology. Now we see auto executives harvesting technologies at the seedling stage from the fields of Silicon Valley, and utility executives sitting on the boards of automotive companies. Tesla itself, and some of the newer auto companies, are in California for a reason – because the culture of innovation is so strong there.”

SEE ALSO: Momentum Dynamics’ Wireless Charging Could Relegate Plugs To History

Meanwhile, we told him we’ve met with unbelief that the engineering is possible, and at worst people say it’s hype, smoke and mirrors, and worse.

“You’re witnessing a classic discomforting paradigm shift. This is normal,” said Daga of changes in the automotive world he sees as about to rapidly unfold.

“What’s happening in the automotive world is going to be amazing and you are going to see entirely new business models arising in the next few years,” said Daga. “Momentum is part of that new paradigm, standing astride both the power and automotive side of this movement.”

An alternate version of this article is also posted at GM-Volt.com