- cross-posted to:
- tech@lemmit.online
- cross-posted to:
- tech@lemmit.online
You must log in or register to comment.
What is the obsession with doing this?
At least the guys trying to power EVs with solar panels on the roof and hood have gone quiet for now.
I could see it being useful for traffic jams, stop and go traffic, and rush hour. EVs would passively gain range in those situations. As a matter of maintaining battery while driving at any sort of real travel speeds? Not worth it.
Article is worth reading. Thanks OP
The photo shows the car getting a 16kW charge rate while driving at 5mph. So you could get 16kWh of energy if you drove on this kind of road for an entire hour, at 5mph. Pretty worthless.
I’d love to know what sort of charge rate you’d get while driving at 35 mph, the standard speed on surface streets. Based on what little I know about inductive charging, I’d guess that the charge rate will be dramatically slower.
But if you get even 5kW while driving at 35 mph, I think that’d actually be pretty useful. Assuming that you get a significant efficiency increase at such a speed (5 mi/kWh seems reasonable), then going 35mph would use up 7KwH of energy per hour of driving. If you can restore 5 of those kWh from the roadway itself, you’re getting back over 70% of your energy usage while you drive.
The question then, however, is “How efficient is the energy transfer?” Because I doubt it’ll be very good. It’ll be rather expensive to pay for that “charge while you drive” power if you’re only getting 30-40% efficiency (at a guess). Some folks might be willing to pay that premium, but by the time this tech is ready to go to market, I imagine most people won’t really feel the need to “charge while you drive”.
The photo shows the car getting a 16kW charge rate while driving at 5mph. So you could get 16kWh of energy if you drove on this kind of road for an entire hour, at 5mph. Pretty worthless.
Or super great for EV’s in urban environments.
Another application would be to run the wireless charging under the parking areas on urban streets and provide car charging for urban residents who use street parking.
Great they are doing the study so we have a good idea of the costs and efficiency of wireless grid EV charging.
Or super great for EV’s in urban environments.
Uh… no? Nobody drives at 5mph for more than a few hundred yards in a parking structure. That’s my point in that sentence, and why I went on to speculate on a possible real-wold use case, using many assumptions that may turn out to be wildly unrealistic.
All wireless chargers are inefficient and there isn’t a known way to make them efficient. There are some theoretical things you could do, like beam steering of the EM field so that more of the energy intersects with the receiving coils, but in practice that’s so insanely expensive as to be fantasy for something as large as a roadway. The efficiency will also never be as good as running the current through a wire.
I think the money would be better spent making EVs cheaper. Or making batteries better. Or adding actual charging stations. Or adding capacity for the grid. Or adding micro grids. Oof.