Oak Ridge N.L. surges forward with 20-kilowatt wireless charging for vehicles | Hacker News Reader

Oak Ridge N.L. surges forward with 20-kilowatt wireless charging for vehicles

ornl.gov

14 pointsiam-TJ8 comments

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).

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/

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

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

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

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

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

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.

It might be worth it in unstaffed commercial settings where ditching the charge wire means one less thing to break.

> 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.

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.

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

They are not wireless, though.

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