
Oak Ridge N.L. surges forward with 20-kilowatt wireless charging for vehicles - iam-TJ
https://www.ornl.gov/news/ornl-surges-forward-20-kilowatt-wireless-charging-vehicles
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IanCal
Does anyone have a source for this that isn't the press release? I'm
struggling to find something more technical. The video talks about 95%
efficiency but the press release says 90%.

Their website doesn't seem to have any real information either, just links to
2011 papers and a note that they work on wireless power transfer.

I assume there's more information somewhere, but I'm completely failing to
find it. It's a shame it's not more common to at least link to in press
releases (or on the video description).

~~~
iam-TJ
Same here, but I did figure out that the technology is a development of the
existing 'Plugless' [0] by Evatran Group, Inc., and found an Idaho N.L. report
dated 2014 [1] "Test Results of the PLUGLESS™ Inductive Charging System from
Evatran Group, Inc." which says:

"... Note that the maximum efficiency for this operation condition of a 100-mm
gap at 3.3 kW is 88.8% at X = −90 mm and Y = −30 mm ..."

Which seems to indicate they've improved the efficiency for the heavy-duty
system that Evatran, Oak Ridge, Clemson and partners are reporting on now.

Then I found [2] "Wireless Charging of Electric Vehicles" which is a July 2015
Oak Ridge N.L. project update that talks about Milestones and the Technical
Accomplishments.

That search of energy.gov led me to another related project [3] "Technology
Requirements and Evaluations for High Power Applications of Wireless Power
Transfer" (on-going research into 100kW+).

And this [4] "High Efficiency, Low EMI and Positioning Tolerant Wireless
Charging of EVs".

[0]
[https://www.pluglesspower.com/about/](https://www.pluglesspower.com/about/)

[1]
[https://avt.inel.gov/sites/default/files/pdf/evse/WirelessCh...](https://avt.inel.gov/sites/default/files/pdf/evse/WirelessChargingTestResultsPaper.pdf)
(warning, TLS X509 certificate is for different sub-domains!)

[2]
[http://energy.gov/sites/prod/files/2015/07/f24/vss103_onar_2...](http://energy.gov/sites/prod/files/2015/07/f24/vss103_onar_2015_o.pdf)

[3]
[http://energy.gov/sites/prod/files/2015/07/f24/vss152_onar_2...](http://energy.gov/sites/prod/files/2015/07/f24/vss152_onar_2015_o.pdf)

[4]
[http://energy.gov/sites/prod/files/2015/07/f24/vss102_lewis_...](http://energy.gov/sites/prod/files/2015/07/f24/vss102_lewis_2015_o.pdf)

~~~
IanCal
Sorry I missed this reply, thank you for all the extra info.

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justsomedood
If I'm reading this right, most plug in systems currently are a third of the
20kW rating of this charger, but this wireless charger is 90% efficient. So
the extra 2kW is just lost to heat? That's a lot of energy to lose - I'm not
sure if the convenience is worth it when it still would be close to a half
hour to charge the 10kWh battery they're testing on.

~~~
IanCal
> If I'm reading this right, most plug in systems currently are a third of the
> 20kW rating of this charger, but this wireless charger is 90% efficient. So
> the extra 2kW is just lost to heat? That's a lot of energy to lose

I'm not sure where the 90% figure in the article comes from, the video says
95% (so that'd be down to 1KW). He also says it's "very close" to the onboard
charger efficiency, but I don't know if that means 95% is close to 99.x% or if
onboard chargers have other losses and maybe it's normal to lose (say) 4% with
current setups.

> I'm not sure if the convenience is worth it when it still would be close to
> a half hour to charge the 10kWh battery they're testing on.

It depends a lot on the use case. If you're trying to replace having to plugin
something overnight it's not really saving you much. But what if parking
spaces had the chargers in? Or taxi-ranks? Busses are another good example
where being able to reduce the required battery would be pretty good.

Edit - reducing the time it takes to charge your battery by reducing the human
element required is good, but how useful it is depends on how long you want to
charge for. Want to charge for half an hour? Not really saving much time
there. Want to charge for 45 seconds here and there throughout the day? Now
you're saving more time.

Wireless doesn't have to be the only way of charging, but it may be
significantly better for some use cases.

~~~
iam-TJ
I was thinking of this in the context of trickle-charging by embedding the
technology in the road at well-known bottle-necks, traffic lights, and
anywhere where there is predictable very slow-moving traffic, as well as in
the obvious candidates such as car parks and parking bays.

For parking bays on public streets in residential areas where on-street
parking is the only option it offers an option _without_ needing to add a lot
of additional pavement furniture (charging pods).

Right now the capital cost versus utilisation equation probably doesn't look
rational, but in 15 years or so when a significant fraction of vehicles are
electric or hybrid it could make a deal of sense.

Not sure if it'll ever happen but the current experiments with (solar) power-
generating road surfaces combined with this and local energy storage could be
interesting. Top up the storage batteries during light traffic; discharge the
storage batteries and charge vehicles during peak traffic periods and
overnight.

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krasin
For comparison, Tesla Superchargers are 120 kW at peak (when charging an empty
battery): [http://insideevs.com/tesla-cranks-superchargers-up-
past-120-...](http://insideevs.com/tesla-cranks-superchargers-up-past-120-kw/)

They are not wireless, though.

