Water/urine/etc ingress and dirt ingress into the connectors and charging controller electronics?
That's why I said capacitive at first, you just need to roughly mate two surfaces. A little bit of dust and even water is not a problem, brush away the worst of it, use say a magnetic clamp to attach your cable. Magsafe for cars.
QuoteHave a chat to the people with experience of telecom footway boxes. They have plenty of experiences of low energy infrastructure. Charging infrastructure can never be low energy
But then what use is their experience?
For higher voltages you could try to have the plug suck vacuum to get a good seal, remaining water inside the socket can be flashed off. You can use a detector electrode just outside the seal as a fail safe so people walking bear foot past a slightly leaky plug don't get tingling feet.
Water/urine/etc ingress and dirt ingress into the connectors and charging controller electronics?
That's why I said capacitive at first, you just need to roughly mate two surfaces. A little bit of dust and even water is not a problem, brush away the worst of it, use say a magnetic clamp to attach your cable. Magsafe for cars.So your solution is to wipe a capacitor clean every evening (even in rain / snow) to charge your car for the next day after a days of hard work and wanting to have dinner? When I get home, I'm done with the car. Many times I don't even lock the car. I just want to go inside, have dinner and enjoy my evening.
But put some numbers to your capacitive charging idea and you'll see that it ends up needing extremely high voltages (likely in the hundreds of kV) to transfer a decent amount of power over a distance (say like 20cm).
Besides, it isn't just the plug/socket, it is everything else in a charger.
This is an engineering forum: to advocate this method, one should include some quantitative estimates.
Consider a much simpler problem: a machine to dispense car parking tickets for parking spaces on the road. Characteristics: above ground, one every 100m or so, low power. Given the proportion of those simple machines that are out of order when you try to buy a ticket, the reliability of roadside chargers is likely to be, um, less than acceptable.
Besides, it isn't just the plug/socket, it is everything else in a charger.
Glue it to the heatsink and pot it. Except for the mains to electronics connection, but no doubt there are good standards and solutions for under ground mains connections already.
A ticket dispenser has UI and mechanical components. A minimal charger will just have a status LED and the connector exposed to humans (far more destructive than water).
This is an engineering forum: to advocate this method, one should include some quantitative estimates.
Capacitive charging at KW level has been done, but with large plates. If you can get away with a small mating surfaces depends on the structural properties of high permittivity ceramics.
Zero surprise here! I only mentioned a (very) few places I could think of that I had been to
tom66 lists his location as "Cambridgeshire". Having lived there I would characterise it asIn other words it does not represent typical UK townscapes.
- a few small old bits
- lots of new bits
- lots of space, even in the old bits
- bloody boring, except for Ely and Cambridge centres
Given that, it isn't surprising if tom66 (and some people from the US on other fora) don't understand the impracticalities of their vision in "other places". Dismissing other people's completely valid experiences of "other places" does not reflect well on them or their position.
Consider a much simpler problem: a machine to dispense car parking tickets for parking spaces on the road. Characteristics: above ground, one every 100m or so, low power. Given the proportion of those simple machines that are out of order when you try to buy a ticket, the reliability of roadside chargers is likely to be, um, less than acceptable.
Follow the money! In the case of the ticket dispenser, the money goes to the City and repair is controlled by City employees. They clearly don't give a damn at any level.
Hopefully, charging points will be owned by private enterprise and they have a profit motive for keeping them ALL working. After all, there is no return on their capital investment if they can't sell kWh.
The .gov should clear the roadblocks but the work/return should all be private enterprise.
We'll get into the discussion of 'red-lining' (crossing out entire neighborhoods) later but that's one of those incentive deals where .gov can actually make a contribution to grease the skids.
In a lot of ways, charging points could be a public utility. I wouldn't want to see it go that way because .gov has too much control over operations. Keeping the service private is probably the best way to go. We have all seen what happens with public utilities.
If there is money to be made, private industry will find it! Kind of like residential solar.
A charger must have the ability to read a payment device, authenticate credit availibility, debit someone's account, and communicate that to the user.
I would prefer to listen to the experience of someone used to working in/under roads than someone presuming it is easy. The last time I had that pleasure was, gulp, 42 years ago at BT Research Labs. Eye opening.
A charger must have the ability to read a payment device, authenticate credit availibility, debit someone's account, and communicate that to the user.
A charger must have the ability to read a payment device, authenticate credit availibility, debit someone's account, and communicate that to the user.
Gas pumps already do this and have for a long time.
Yes and no. EV charging stations typically don't accept debit or credit cards. OTOH every manned / unmanned gas pump does. For some reason companies that run EV chargers deemed it necessary to invent their own cards which are not interchangeable.
A charger must have the ability to read a payment device
Numbers please, e.g. voltages, currents, components, x/y/z dimensions.
A charger must have the ability to read a payment device, authenticate credit availibility, debit someone's account, and communicate that to the user.
Gas pumps already do this and have for a long time.Yes and no. EV charging stations typically don't accept debit or credit cards. OTOH every manned / unmanned gas pump does. For some reason companies that run EV chargers deemed it necessary to invent their own cards which are not interchangeable.
A charger must have the ability to read a payment device
At the point you're filling the entire country with chargers, it's far cheaper to just give people without a mobile phone one with a free sim, which can only be used to access a payment portal.
Regardless of any other aspect of the design, it will massively simplify the charger.QuoteNumbers please, e.g. voltages, currents, components, x/y/z dimensions.
Papers for existing prototype systems you can look up yourself.
Lets say a 4 plate system with plates 10x10cm. Then with 2 mm of 100x relative permittivity insulator the series capacitance would be around 2 nF. At 100 kHz that's an impedance of 5k. Lets assume simple impedance matched resistive load to get some ballpark figure, 1800V RMS required for 3 kW. Ballpark doable with a high permittivity insulator, without it not so much.
A charger must have the ability to read a payment device, authenticate credit availibility, debit someone's account, and communicate that to the user.
Gas pumps already do this and have for a long time.
QuoteI would prefer to listen to the experience of someone used to working in/under roads than someone presuming it is easy. The last time I had that pleasure was, gulp, 42 years ago at BT Research Labs. Eye opening.
But it is already known how to do this. I don't know how but there are thousands of people who do. This is just a tiny detail. BTW, we did that at a company I worked for when we wanted to run an 8" chilled water line among 3 buildings without tearing up the lawn and buried utilities. Worked well!
Yes and no. EV charging stations typically don't accept debit or credit cards. OTOH every manned / unmanned gas pump does. For some reason companies that run EV chargers deemed it necessary to invent their own cards which are not interchangeable.
Err... how many have you used? Every new DC charger in the UK has to accept contactless payment, and a good majority of older ones do already. (They don't require PINs so no keypad is needed, just a contactless reader.) This also appears to the way the EU is going. The vast majority don't bother with RFID cards any more because yeah, it is a hassle, they just work with mobile apps. These apps vary from "dreadful" (BP Pulse, really, just best avoided) to "really good" (PodPoint). Perhaps expecting an oil company to make good EV charging infrastructure is foolish.
The ideal outcome I would see for EV charging is it being an extension of your home electricity bill. The electrons are all the same after all. Just pay the service fee for the charger (per kWh or maybe, for DC charging, a fixed fee) and you get whatever rate your supplier negotiated for your usage. And the service fees should be fixed to some reasonable rate covering normal wear and tear of the charging equipment.
A charger must have the ability to read a payment device
At the point you're filling the entire country with chargers, it's far cheaper to just give people without a mobile phone one with a free sim, which can only be used to access a payment portal. App can have a bluetooth mode with an in-app reserve for when mobile data is down.
Regardless of any other aspect of the design, it will massively simplify the charger.QuoteNumbers please, e.g. voltages, currents, components, x/y/z dimensions.Papers for existing prototype systems you can look up yourself.
Lets say a 4 plate system with plates 10x10cm. Then with 2 mm of 100x relative permittivity insulator the series capacitance would be around 2 nF. At 100 kHz that's an impedance of 5k. Lets assume simple impedance matched resistive load to get some ballpark figure, 1800V RMS required for 3 kW. Ballpark doable with a high permittivity insulator, without it not so much.
It's not for convenience, it's to be able to put the charging connector on the curb and take up no room.
I'm not saying it's _the_ solution, I'm just saying in high density older European towns every solution to curb side charging has a ton of problems. The simple solution of just putting a charging pole every 6 meters will not work, not because of material cost but simply because it will make the street completely unusable. Every not simple solution is pretty far out there.
PS. all the pop up charger test runs don't seem to have UI either, so presumably all app based. But even popup chargers will take up a ton of extra space on the curb, unless there's so many of them they can pop up in between cars.
Zero surprise here! I only mentioned a (very) few places I could think of that I had been to
tom66 lists his location as "Cambridgeshire". Having lived there I would characterise it asIn other words it does not represent typical UK townscapes.
- a few small old bits
- lots of new bits
- lots of space, even in the old bits
- bloody boring, except for Ely and Cambridge centres
Given that, it isn't surprising if tom66 (and some people from the US on other fora) don't understand the impracticalities of their vision in "other places". Dismissing other people's completely valid experiences of "other places" does not reflect well on them or their position.
tom66 spent most of his student life in Leeds and used to park on a terraced street near Headingley Stadium with a small car. (Match days were not fun - do not move your car, you will not be able to park again.) tom66 also grew up in Hampshire in a small village with mostly street parking. Currently I do have a driveway (it was a non-negotiable requirement when buying the house) but probably not enough space for a second car without remodelling the drive somewhat so when we do have two electric cars we will just alternate charging requirements between these cars. The street I currently live on is alike many in semi-urban England - a mix of street parking and driveways, representative of the "25% of people*" not having access to off street parking. I look at my street as being pretty representative of most, a mix of detached, semi-detached, terraced and bungalows, mostly built before the 1950's before cars were very popular, but actually not that difficult to serve for charging requirements.
I do not currently live in Cambridgeshire, I moved to Northamptonshire six months ago. I would describe Northamptonshire as one of the most 'normal' counties I have lived in. It very much just looks like England.
I do not see street charging for EVs as unsolvable but like many problems it will need solutions appropriate to the area. Pavement gulleys (and sure, let's fine people who leave their cables out, I'm absolutely okay with that, but let's also fine people who park unnecessarily on the footway, too),
pop up chargers, small posts, lamppost charging. and for those who have it, charging at home. Nothing about this is impractical, especially given there's at least 10-15 years before EVs become even a significant proportion of total vehicles on the road, and if you look at bigger cities the solutions are already appearing.
I'm also not sure exactly what your proposed alternative *is*, if your assumption is EVs cannot work for the vast majority due to charging headaches. We cannot continue to burn petrol, because climate change is a thing, ...
most people do depend on their car so public transport alone won't pick up the slack, so we do have to figure this out. So, what, do you want to see ...
*25% is better than the earlier 50% figure I'd quoted from the AA, but they were probably not including anything but driveways in their estimation. Driveways are the easiest problem to solve for EV charging, but off-road parking in a shared lot is probably the second easiest, though requires more negotiation between parties (LA, landlord/land owner/etc.)