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I'm in China where everybody rides ebikes and my building has a free for all parking space where 2/3rds of the parks have no chargers and the spots with charge

I'm in China where everybody rides ebikes and my building has a free for all parking space where 2/3rds of the parks have no chargers and the spots with charge ports all have qr codes you scan and pay with wechat to turn the port on. This is an easy problem to solve.

bartvk 6y ago
Just curious, what's the kWh price for this? Here in The Netherlands, we get charged about 0.33 euro per kWh (= 0.40 US$), and that's for overnight charging of cars, where you typically draw no more than 11 kW.
- OJFord 6y ago
  How does that compare to your household €/kWh? I appreciate there's a value-add, just seems a lot compared to mine (£0.12something). I suppose if expect to pay roughly a day's standing charge, plus the kWh used. I'd rather pay for it like that than roll it together and have my overnight charge subsidise someone else's 30min top-up.
- TheSmiddy 6y ago
  I pay ¥2 for 6 hours at 400w (2400w total) which is ¥0.83/kwh or US$0.128. My household electricity is about 30% cheaper so it's a pretty good deal.
lostlogin 6y ago
It sounds good - but the dark side of wechat and social credit lurks in the back of my mind. That is not an easy problem to solve.
- TheSmiddy 6y ago
  WeChat is just how things are paid for here, obviously the solution would not rely on WeChat in any other country. In Australia you'd just tap your credit card.
- Daho0n 6y ago
  Of course it is easy. You can just pay with a credit card or mobile payment etc. like is already done when paying for parking. Even easier, the charging around where I live you have an account and a card and you just swipe and charge and the bank transfers the money monthly. Solved many years ago. The only thing that isn't all the way solved is the massive drain charging lots of cars at the same time can induce.
i_am_proteus 6y ago
An electrobike is a substantially lower electrical load than an electrocar. Many existing residential buildings can't handle adding a EV charging spot per unit (probably needs a 100A breaker each).
- iso1631 6y ago
  A Tesla gets about 3 miles from 1kWh. Average car in the UK does 140 miles a week, or 50kWh, or about 1kW of constant draw for 8 hours a night, or 4 amps. That's not an excessive amount compared with peak morning usage when everyones showers and dishwashers are starting.
  - i_am_proteus 6y ago
    The four-amp draw in your calculations provides the user a 12-mile operating radius each day. Somewhat to my original point: an electrobike is a much lower load than an electrocar! This might be acceptable on average; theory in practice are the same in theory, but in practice they differ. A real-world user will require the ability to fully charge his electrocar on occasion, which means the fullbore 240V connection and a 100A breaker (potentially a 50A breaker depending on vehicle). Assuming that every user follows average patterns will break the system. Taking this idea out further, it speaks to infrastructure upgrades that will be necessary in order to power all of these electrocars. Estimates vary by region, power generation from automobiles as a fraction of total is somewhere between 10% and 30%, which exceeds both the spare capacity of the electric grid in aggregate, as well as often exceeding local transmission capabilities. All-in-all, the costs of electrocar adoption are nonlinear: the first few percent of the population who adopt don't have to deal with the structural problems: a 100-unit condominium building can add two or three 240V chargers, the local grid can handle a handful of vehicles. At scale, however, major infrastructure upgrades will be required.
    - iso1631 6y ago
      One of my cars does 30 miles a day and is in the driveway from 1600-0730, so needs 10kwH in 15 hours, or a draw of 700W. 10 years ago the lights in my house drew about 700W. The other car does 6 miles 3 times a week and is in the driveway almost all the time. Sure, there are whales that do 300 miles a week, but that's not most people. Looking at a sample of about 13 million vehicles that passed MOT tests in both 2018 and 2019, and thus reported the milage Percentiles 20%: 2700 40%: 4800 50%: 6000 60%: 7000 80%: 10500 90%: 14000 95%: 17000 Lets assume that's all commuting over 5 days a week, 47 weeks a year. That means in an average 12 hour night: 20% of cars would need less than 11 miles of charge, or 4kWh -- 350W Another 20% of cars would need less than 21 miles of charge, or 7kWh -- 600W Another 20% of cars would need less than 10kWh -- 850W Another 20% of cars would need less than 15kWh -- 1.25kW Another 15% of cars would need 24kWh -- 2kW All of that is less than a kettle, an average 13A plug is more than enough. Now if those mileages include many people doing long distance drives at weekends and not regular commuting, the actual top-up needed every night isn't anywhere near as much. Some cars will do lots of miles at the weekend and need to draw the full 3kW out of a standard socket, sure. My kettle doesn't have an issue with doing that. For every car needing that full charge on a Sunday and during the rest of the week, there's a dozen that don't. OK, your battery might be down to 10% on Sunday night, but then you charge it to 20% for Monday morning, drop to 17% after your commute, charge to 27% Tuesday, and so on. 100A, or even 60A, house breakers aren't going to have an issue with keeping 95% of cars topped up, so you're at the next level. On the rare occasion you need to fully recharge really quickly, go to a specialist location with a 20kW+ charger. The data shows that most people won't need that most of the time. Looking at newer cars -- ones made in 2016 (and thus having first MOT in 2019), you'd think they'd have a higher mileage. And they do, median is 8400, and 80%ile is 13,300, 95% 22700 -- about 30% higher in each bracket, but that's still well within a home charge range, even for the 95%ile, and only 1 in 4 cars are new enough to be in that category, so median mileage of all cars would be under 7,000 miles a year range. You're right there's a grid level problem -- the dip in power generation in the UK overnight is about 10GW, which could sustain about 14 million cars - not too great when there's more than twice that needing power. Assuming that in a given area cars are distributed fairly evenly as above, with some cars needing 24kWh a night, but others needing 4kWh, the average overnight draw would still only be 700W, that doesn't feel like it's going to trip neighbourhood substations, but further upstream could be problems.

bartvk 6y ago

Just curious, what's the kWh price for this? Here in The Netherlands, we get charged about 0.33 euro per kWh (= 0.40 US$), and that's for overnight charging of cars, where you typically draw no more than 11 kW.

OJFord 6y ago
How does that compare to your household €/kWh? I appreciate there's a value-add, just seems a lot compared to mine (£0.12something). I suppose if expect to pay roughly a day's standing charge, plus the kWh used. I'd rather pay for it like that than roll it together and have my overnight charge subsidise someone else's 30min top-up.
TheSmiddy 6y ago
I pay ¥2 for 6 hours at 400w (2400w total) which is ¥0.83/kwh or US$0.128. My household electricity is about 30% cheaper so it's a pretty good deal.

lostlogin 6y ago

It sounds good - but the dark side of wechat and social credit lurks in the back of my mind. That is not an easy problem to solve.

TheSmiddy 6y ago
WeChat is just how things are paid for here, obviously the solution would not rely on WeChat in any other country. In Australia you'd just tap your credit card.
Daho0n 6y ago
Of course it is easy. You can just pay with a credit card or mobile payment etc. like is already done when paying for parking. Even easier, the charging around where I live you have an account and a card and you just swipe and charge and the bank transfers the money monthly. Solved many years ago. The only thing that isn't all the way solved is the massive drain charging lots of cars at the same time can induce.

i_am_proteus 6y ago

An electrobike is a substantially lower electrical load than an electrocar. Many existing residential buildings can't handle adding a EV charging spot per unit (probably needs a 100A breaker each).

iso1631 6y ago
A Tesla gets about 3 miles from 1kWh. Average car in the UK does 140 miles a week, or 50kWh, or about 1kW of constant draw for 8 hours a night, or 4 amps. That's not an excessive amount compared with peak morning usage when everyones showers and dishwashers are starting.
- i_am_proteus 6y ago
  The four-amp draw in your calculations provides the user a 12-mile operating radius each day. Somewhat to my original point: an electrobike is a much lower load than an electrocar! This might be acceptable on average; theory in practice are the same in theory, but in practice they differ. A real-world user will require the ability to fully charge his electrocar on occasion, which means the fullbore 240V connection and a 100A breaker (potentially a 50A breaker depending on vehicle). Assuming that every user follows average patterns will break the system. Taking this idea out further, it speaks to infrastructure upgrades that will be necessary in order to power all of these electrocars. Estimates vary by region, power generation from automobiles as a fraction of total is somewhere between 10% and 30%, which exceeds both the spare capacity of the electric grid in aggregate, as well as often exceeding local transmission capabilities. All-in-all, the costs of electrocar adoption are nonlinear: the first few percent of the population who adopt don't have to deal with the structural problems: a 100-unit condominium building can add two or three 240V chargers, the local grid can handle a handful of vehicles. At scale, however, major infrastructure upgrades will be required.
  - iso1631 6y ago
    One of my cars does 30 miles a day and is in the driveway from 1600-0730, so needs 10kwH in 15 hours, or a draw of 700W. 10 years ago the lights in my house drew about 700W. The other car does 6 miles 3 times a week and is in the driveway almost all the time. Sure, there are whales that do 300 miles a week, but that's not most people. Looking at a sample of about 13 million vehicles that passed MOT tests in both 2018 and 2019, and thus reported the milage Percentiles 20%: 2700 40%: 4800 50%: 6000 60%: 7000 80%: 10500 90%: 14000 95%: 17000 Lets assume that's all commuting over 5 days a week, 47 weeks a year. That means in an average 12 hour night: 20% of cars would need less than 11 miles of charge, or 4kWh -- 350W Another 20% of cars would need less than 21 miles of charge, or 7kWh -- 600W Another 20% of cars would need less than 10kWh -- 850W Another 20% of cars would need less than 15kWh -- 1.25kW Another 15% of cars would need 24kWh -- 2kW All of that is less than a kettle, an average 13A plug is more than enough. Now if those mileages include many people doing long distance drives at weekends and not regular commuting, the actual top-up needed every night isn't anywhere near as much. Some cars will do lots of miles at the weekend and need to draw the full 3kW out of a standard socket, sure. My kettle doesn't have an issue with doing that. For every car needing that full charge on a Sunday and during the rest of the week, there's a dozen that don't. OK, your battery might be down to 10% on Sunday night, but then you charge it to 20% for Monday morning, drop to 17% after your commute, charge to 27% Tuesday, and so on. 100A, or even 60A, house breakers aren't going to have an issue with keeping 95% of cars topped up, so you're at the next level. On the rare occasion you need to fully recharge really quickly, go to a specialist location with a 20kW+ charger. The data shows that most people won't need that most of the time. Looking at newer cars -- ones made in 2016 (and thus having first MOT in 2019), you'd think they'd have a higher mileage. And they do, median is 8400, and 80%ile is 13,300, 95% 22700 -- about 30% higher in each bracket, but that's still well within a home charge range, even for the 95%ile, and only 1 in 4 cars are new enough to be in that category, so median mileage of all cars would be under 7,000 miles a year range. You're right there's a grid level problem -- the dip in power generation in the UK overnight is about 10GW, which could sustain about 14 million cars - not too great when there's more than twice that needing power. Assuming that in a given area cars are distributed fairly evenly as above, with some cars needing 24kWh a night, but others needing 4kWh, the average overnight draw would still only be 700W, that doesn't feel like it's going to trip neighbourhood substations, but further upstream could be problems.