U.K. to test roads that charge electric cars as they drive - Page 1
Forum section: electronics / general

author: Zucca
author_rank: Unknown
timestamp: August 20, 2015, 07:11:23 am
content: http://globalnews.ca/news/2171804/uk-to-test-roads-that-charge-electric-cars-as-they-drive/makes more sense than the solar f. roadways bull... still I am asking myself if it is possible that system will do the job fine...Anyone has technical details?

author: daqq
author_rank: Super Contributor
timestamp: August 20, 2015, 07:45:07 am
content: I'm sure it's possible, but it's yet another one of those systems that just throws efficiency of transfer out the window, would be obscenely pricey for any larger implementation...I'm all for electric cars, but I don't think this is the way.

author: Deathwish
author_rank: Unknown
timestamp: August 20, 2015, 09:03:47 am
content: I wonder which tax will go up to support it

author: Psi
author_rank: Super Contributor
timestamp: August 20, 2015, 09:11:32 am
content: Whats wrong with using all the offpeak capacity in the national grid to charge up your car overnight.The grid is built to support the peak loading, so there's plenty of available power midnight to 6am

author: Mechanical Menace
author_rank: Super Contributor
timestamp: August 20, 2015, 09:35:26 am
content: Quote from: Deathwish on August 20, 2015, 09:03:47 amCouncil tax pays for the roads. Councils (and therefore roads) outside of London get some help from central government once every 90 years. So most likely the council tax.Quote from: Psi on August 20, 2015, 09:11:32 amBattery capacity and the extra weight needed to have enough of it probably.

author: firewalker
author_rank: Super Contributor
timestamp: August 20, 2015, 09:42:20 am
content: The coupling between the car and the road, will add an extra drag to the car. Yes?Alexander.

author: Delta
author_rank: Super Contributor
timestamp: August 20, 2015, 12:43:57 pm
content: What waste of money. Similar in fact to solar roadways, it will work in a way, but but hopelessly inefficient both electrically and economically.

author: amyk
author_rank: Super Contributor
timestamp: August 20, 2015, 01:57:07 pm
content: https://en.wikipedia.org/wiki/Trolleybus

author: zapta
author_rank: Super Contributor
timestamp: August 20, 2015, 02:37:45 pm
content: T = L / S. The faster the vehicle drives the longer active road you need to have the same charging time.More bang for the buck installing it before intersections and setting a very long red time for the HOV lane where the EVs travel.

author: Zucca
author_rank: Unknown
timestamp: August 20, 2015, 02:46:50 pm
content: I wonder if in case of rain a wet road surface will take down the efficiency. Maybe the surface will dry up because the coil will heat up the water...

author: Dave
author_rank: Super Contributor
timestamp: August 20, 2015, 03:44:05 pm
content: The magnetic coupling would probably be terrible. Not only would there be a massive air gap in the magnetic circuit, but the coils in the idea image look way too big. They would need to have much smaller coils (3-4 meters in length max) that are overlapped and have some smart circuitry that would switch between the coils as the vehicle travels along.The transmission powers would need to be insane (tens of kilowatts) to produce any usable amount of power in the receiver. Good luck sliding that past the environmentalists.Also, what happens when someone hangs a hand out of the window with a ring on their finger or a metal bracelet on their wrist?I think this idea is going to end just like solar roadways.

author: Zucca
author_rank: Unknown
timestamp: August 20, 2015, 03:56:32 pm
content: Quote from: amyk on August 20, 2015, 01:57:07 pman alternative...

author: miguelvp
author_rank: Super Contributor
timestamp: August 20, 2015, 07:41:40 pm
content: I just hope they don't have a glitch that makes the induction coil change frequency up to several hundreds kHz and cars start to melt while cooking the passengers at the same time.

author: Red Squirrel
author_rank: Super Contributor
timestamp: August 20, 2015, 08:07:31 pm
content: Neat idea but think of all the copper that will be needed.I think the super charger stations that Tesla has are a much better idea, Think they charge in like less than an hour? People will just have to change their ideas about "fueling up" when traveling and take that time as a break. Put these stations at restaurants. Park, charge up and go inside and eat. When travelling you have to stop to eat at some point anyway. For day to day usage you can just charge over night. Would be cool if electric cars had solar panels on the roof too, would trickle charge the battery while it's parked. Ex: if you drive to work and car sits there all day and sun is out you'd have a full charge by the time you go home. Excess power could also go to the battery in winter to keep it at an optimal temp, more dump load could go in the cabin or windshield to melt the snow as it accumulates.Though I just thought of something, wonder if a high frequency coil could be added in your driveway to melt the snow off the car in the morning. Would be set on a timer an hour before you have to leave. The chassis would get hot and warm the rest of the car up. You'd probably need a ridiculous amount of power for it mind you.

author: ajb
author_rank: Super Contributor
timestamp: August 20, 2015, 08:22:51 pm
content: Quote from: Red Squirrel on August 20, 2015, 08:07:31 pmLet's see, if the footprint of the car is roughly 2x3m, 1cm of snow is a total of .006m^3, assuming the snow water equivalent is 12%, that's equivalent to .0072m^3 or 7.2kg of water. Heat of fusion of water is 334.8J/g, so to melt a one centimeter layer of snow off your car you'd only need. . . 2.4MJ, which works out to 670W if you can afford to wait an hour. Of course that doesn't include the energy required to get the snow from whatever temperature up to 0C, or heat lost to the car, air, and system efficiencies in the process.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: August 20, 2015, 08:29:38 pm
content: When I had to worry about snow and cars I had remote starts lol. Had to learn the hard way about leaving cars in gear though...

author: Red Squirrel
author_rank: Super Contributor
timestamp: August 20, 2015, 09:05:57 pm
content: Quote from: ajb on August 20, 2015, 08:22:51 pmThat actually seems feasible... mind you that's probably assuming the energy is going straight to the snow, which it would not. In real life situation probably need a couple kw. Probably more efficient to just have a heater on the dash to defrost the windows. Of course would need to figure out if the cost in gas to warm it up is more expensive than the power for such a heater otherwise may as well just keep using remote start. Gas keeps going up at a faster rate than hydro though.