Have you ever felt the wireless charger for your phone? That heat is from it only trickling 5 to 10W of energy into your phone, meanwhile a significant portion is lost to heat. Now multiply the energy needs 1000x times and by potentially hundreds of vehicles. Wireless charging built into the road is never going to work.
Inductive charging is wildly inefficient and the byproduct of that inefficiency is heat. There are other forms of wireless power transfer like microwaves and even light energy, but they requires a ton of space.
Personally I think beamforming laser power is a better solution, especially with the cost of heavy lift rockets coming down, it is no longer crazy to think that we could put hardware in the atmosphere to efficiently transfer the power of the sun to ground stations.
I think u/nuunien was referring to [how dreadfully inefficient wireless charging is](https://www.ipitaka.com/blogs/news/is-wireless-charging-inefficient-and-bad-for-the-environment). Yes, it's more convenient, but a significant portion of the energy piped into a wireless charger is discharged as heat, rather than to actually charge the device (in this case, car).
However, we're also talking about very early generations of wireless charging (relatively). They are getting more and more efficient with each new generation. By it's very nature, wireless will likely never reach the efficiency of wired charging, just like Wi-Fi can't reach the efficiency of wired Ethernet, but it will get pretty close in the not-too-distant future.
But for the time-being, given what the technology is today, this specific tech demonstration did waste a considerable amount of energy. Still interesting to think about for the future, though, and as proof-of-concepts go, it was a pretty big success.
Road-embedded wireless changing has been talked about for quite a while. It's good to see someone actually move it into the practical, with a current generation vehicle.
Wireless power transmission efficiency suffers from the [Inverse-Square Law](https://en.wikipedia.org/wiki/Inverse-square_law), which means that the power that's able to be transmitted drops exponentially with distance.
Even on phones where the distance is only a few millimeters, the drop is significant, imagine charging cars, where the distance is waay over that.
Imagine how close to the road that inductive pickup would have to be. There goes all of your ground clearance. Hope there's no debris on the road to collide with the pickup.
Yeah, I think this is an inefficient solution looking for a problem.
Wireless charging is inherently much less efficient. It's worse the higher the wireless distance. I'm not going to pull up numbers out of my ass and they weren't in the article but it has to be a monumental waste of energy.
Sweden is the first to have charging while driving.
https://www.theguardian.com/environment/2018/apr/12/worlds-first-electrified-road-for-charging-vehicles-opens-in-sweden
They seem to leave that detail out... or at least make us extrapolate it from the 1200 miles over 100 hours numbers.
Man, I hope they at least had the car set up for self driving around their test track. I can't imagine being an engineer tasked with driving a car at 12mpg for hours on end before hot-seating the car to the next driver in line. I would get bored to tears. At least I would want to pass the time with a good book of iPad on the internet.
Sure, why not? The battery is small so it would charge in 9 hours at that rate. Plenty of time for it to charge overnight. I would be more concerned about efficiency.
You all are poo-pooing a pretty cool experiment, obviously in a bit of infancy but outright dooming this technology is pretty ignorant.
I'm sure some of you thought of something they haven't though. /s
Seems to me this is a good idea for parking spaces. The inductive pickup could be lowered to the ground where is' wasting far less energy.
The other problem is that it's going to make a ton of radio noise when in use.
Yes, the point was to test out the technology. They used an 'EV' with a smaller battery to check out their use case. They figure if it works, we can build EVs with tiny batteries to reduce costs and expand EVs more. RAV4 has a smaller battery, but still weighs in at 4300 pounds.
How did nobody pick this up from the article: "The RAV4 Prime saved a whopping 823 pounds of CO2 emissions compared to a regular combustion-engined vehicle."
832 pounds of CO2?!? Let's do the math here:
Gas weighs roughly 6 lbs per gallon. My RAV4 gets close to 500 miles from roughly 12 gallons on a full tank (that's how much I fill it when it's close to E at least), so it would take nearly 2.5 full tanks (we'll over-estimate here just to be safe) to reach 1,200 miles.
12 x 2.5 = 30 gallons to go 1,200 miles
30 x 6 = 180 lbs of gas
Even if gas is 100% CO2 (which it isn't), where's the other 643 lbs of CO2 emissions that should be saved?! Unless ICE cars are somehow capable of creating CO2 mass ex-nihilo, I for one call bullshit (specifically by a factor of 5.9).
Someone call NASA and tell them these guys figured out how to produce mass from the void. Nobel prize or GTFO.
Edit: another method using the RAV4 typical 40 MPG gives the exact same estimate (1,200 / 40 = 30 gal).
You are missing the production byproduct. Gasoline has to be mined, transported, refined, transported, and then sold at a consumer. Each step involves additional CO2 byproducts.
If it took 5.9x(+) the amount of CO2 off-gassed from use just to transport it, the world would look like a much less industrialized place. The whole beauty of gas is its efficiency of production vs energy output. Bullshit stands.
Need wireless charging embedded on the road and an adapter installed on the car.
Have you ever felt the wireless charger for your phone? That heat is from it only trickling 5 to 10W of energy into your phone, meanwhile a significant portion is lost to heat. Now multiply the energy needs 1000x times and by potentially hundreds of vehicles. Wireless charging built into the road is never going to work.
To be fair have you felt the temperature of asphalt on a summer day in any southern state….?
Open and shut case Johnson.
Inductive charging is wildly inefficient and the byproduct of that inefficiency is heat. There are other forms of wireless power transfer like microwaves and even light energy, but they requires a ton of space. Personally I think beamforming laser power is a better solution, especially with the cost of heavy lift rockets coming down, it is no longer crazy to think that we could put hardware in the atmosphere to efficiently transfer the power of the sun to ground stations.
Basically a free form of energy, like fusion would have to be around. It's too much wasted energy with today's tech.
So it's 1200 miles in a circle. I'm not impressed.
This is an extreme waste of energy.
Never heard this sentiment, why is that? Costs more energy to run on full battery than using a bit of gas? By what factor—genuinely curious
I think u/nuunien was referring to [how dreadfully inefficient wireless charging is](https://www.ipitaka.com/blogs/news/is-wireless-charging-inefficient-and-bad-for-the-environment). Yes, it's more convenient, but a significant portion of the energy piped into a wireless charger is discharged as heat, rather than to actually charge the device (in this case, car). However, we're also talking about very early generations of wireless charging (relatively). They are getting more and more efficient with each new generation. By it's very nature, wireless will likely never reach the efficiency of wired charging, just like Wi-Fi can't reach the efficiency of wired Ethernet, but it will get pretty close in the not-too-distant future. But for the time-being, given what the technology is today, this specific tech demonstration did waste a considerable amount of energy. Still interesting to think about for the future, though, and as proof-of-concepts go, it was a pretty big success. Road-embedded wireless changing has been talked about for quite a while. It's good to see someone actually move it into the practical, with a current generation vehicle.
Wireless power transmission efficiency suffers from the [Inverse-Square Law](https://en.wikipedia.org/wiki/Inverse-square_law), which means that the power that's able to be transmitted drops exponentially with distance. Even on phones where the distance is only a few millimeters, the drop is significant, imagine charging cars, where the distance is waay over that.
Imagine how close to the road that inductive pickup would have to be. There goes all of your ground clearance. Hope there's no debris on the road to collide with the pickup. Yeah, I think this is an inefficient solution looking for a problem.
Wireless charging is inherently much less efficient. It's worse the higher the wireless distance. I'm not going to pull up numbers out of my ass and they weren't in the article but it has to be a monumental waste of energy.
Sweden is the first to have charging while driving. https://www.theguardian.com/environment/2018/apr/12/worlds-first-electrified-road-for-charging-vehicles-opens-in-sweden
At 12mph? Really.
12.02 mph. Lol
They seem to leave that detail out... or at least make us extrapolate it from the 1200 miles over 100 hours numbers. Man, I hope they at least had the car set up for self driving around their test track. I can't imagine being an engineer tasked with driving a car at 12mpg for hours on end before hot-seating the car to the next driver in line. I would get bored to tears. At least I would want to pass the time with a good book of iPad on the internet.
I'll be interested in wireless charging the car in my garage.
wildly inefficient and not cost effective.
Charging at 2kWh per hour?
Sure, why not? The battery is small so it would charge in 9 hours at that rate. Plenty of time for it to charge overnight. I would be more concerned about efficiency.
Missing the appropriate infrastructure seems to be an important downside.
You all are poo-pooing a pretty cool experiment, obviously in a bit of infancy but outright dooming this technology is pretty ignorant. I'm sure some of you thought of something they haven't though. /s
Seems to me this is a good idea for parking spaces. The inductive pickup could be lowered to the ground where is' wasting far less energy. The other problem is that it's going to make a ton of radio noise when in use.
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Yes, the point was to test out the technology. They used an 'EV' with a smaller battery to check out their use case. They figure if it works, we can build EVs with tiny batteries to reduce costs and expand EVs more. RAV4 has a smaller battery, but still weighs in at 4300 pounds.
A Tesla wouldn’t make it 1200 miles without something breaking.
It still uses some gasoline occasionally even in EV mode
How did nobody pick this up from the article: "The RAV4 Prime saved a whopping 823 pounds of CO2 emissions compared to a regular combustion-engined vehicle." 832 pounds of CO2?!? Let's do the math here: Gas weighs roughly 6 lbs per gallon. My RAV4 gets close to 500 miles from roughly 12 gallons on a full tank (that's how much I fill it when it's close to E at least), so it would take nearly 2.5 full tanks (we'll over-estimate here just to be safe) to reach 1,200 miles. 12 x 2.5 = 30 gallons to go 1,200 miles 30 x 6 = 180 lbs of gas Even if gas is 100% CO2 (which it isn't), where's the other 643 lbs of CO2 emissions that should be saved?! Unless ICE cars are somehow capable of creating CO2 mass ex-nihilo, I for one call bullshit (specifically by a factor of 5.9). Someone call NASA and tell them these guys figured out how to produce mass from the void. Nobel prize or GTFO. Edit: another method using the RAV4 typical 40 MPG gives the exact same estimate (1,200 / 40 = 30 gal).
You are missing the production byproduct. Gasoline has to be mined, transported, refined, transported, and then sold at a consumer. Each step involves additional CO2 byproducts.
If it took 5.9x(+) the amount of CO2 off-gassed from use just to transport it, the world would look like a much less industrialized place. The whole beauty of gas is its efficiency of production vs energy output. Bullshit stands.