Electric cars

zeupater

AdrianC wrote: »

I said "ultimately unsustainable", and assumed that the implicit "once a substantial proportion of the employees drive EVs" would be understood.


If there's 20 chargers (£8.40/car x 20 = £168/day, £840/week, £44k/year - not to mention the extra 140kW demand), then as soon as there are 21 EVs, the last one in is not charging. A little bit of overlap's not the end of the world for users to manage, because you can arrange with Dave in Accounts to swap over at lunchtime - but once there are significantly more EVs than chargers, it's going to start to cause real problems, with senior management EV users having spaces allocated.

Once there are a lot more EVs than chargers, you're going to find HR imposing restrictions on who's authorised to use them as part of the perks package. In a way, that's easier for the users than the 8.30 lottery, because they have foreknowledge.

Hi

However, that assumes no shutdown period & every of the 20 vehicles requiring to be charged from empty to full on a 7kW charger each day!

If the cost is £840/day, then applying (say) 14p/kWh gives a daily charge requirement of 60kWh (840/14) which at 4miles/kWh would resolve to around 240miles of driving each & every workday. Considering that the argument is based on the employee's vehicle being on a workplace car park all day & we're talking about employee owned vehicles, it's not likely to belong to someone driving as part of their job, so what this would effectively describe is a daily 4-5Hr (120mile each way) total commute, which is more than slightly atypical ....

Realistically, a vehicle with around 60kWh of storage on average mileage would need charging around every ~10 days, so by allocating most of the charge spaces to a schedule the facilities can be shared to a degree which multiplies the vehicle capacity by a factor of 10x, the ability of the chargers to service 20 EVs becomes a more realistic 200 cars ... add in weekend daytime working (shops/maintenance teams etc) and it becomes 280, add in two shift working and you pass 500, and three shifting gives a theoretical 'rough-cut' capacity limit closer to 800 .... effectively, if you're the 21st employee to buy an EV when there's 'only' twenty 7kW chargers on the workplace car park, it's not really such a worrying position to be ...

... far more worrying would be a management structure that believed the logic behind ... "Once there are a lot more EVs than chargers, you're going to find HR imposing restrictions on who's authorised to use them as part of the perks package. In a way, that's easier for the users than the 8.30 lottery, because they have foreknowledge." ... as opposed to scheduling a simple employee/charger rota and managing it through the HR system ...

HTH
Z

Martyn1981

Herzlos wrote: »

*I think that currently means going out and changing plugs every 90 minutes, not too onerous, but presumably it'd be possible to provide a charging point with 6 cables that charges either sequentially or in a round-robin style, so that everyone parks up, plugs in and gets charged at some point over the 9 hour day.

I think that sounds entirely sensible. A good set up would be a charger in the center of 4 parking spaces and 4 cables. Not everyone will charge every day, but as you say a round robin charge cycle or a reduced charge rate (don't the Tesla superchargers have a lower rate if two cars are charging rather than one?)

Assuming the entire average car use of 22 miles per day is used solely for work commuting, and no charging is done at home/elsewhere, then the charger would have to provide:

22miles * 7/5 = 30.8 miles divided by 4 miles/kWh = 7.7kWh * 4 cars = 30.8kWh, divided by 8hrs = 3.85kW.

Is that all, sounds too low?

Assuming 22 miles with half charged elsewhere and all charged elsewhere on weekends we get 11 miles /4miles per kWh = 2.75kWh * 4 cars / 8hrs = 1.38kW.

I smell more Ade FUD.

Herzlos

AdrianC wrote: »

that'll give a bit over 150 mile range - 75 miles each way, if we assume that beneficiaries of free workplace charging use that instead of paying for home charging. A long commute, but not unheard of. I've certainly done further in the past.

The average commute is about 15 miles, so 1/5th of the full day charge range.
You may have commuted more than 75 miles each way but that's hugely atypical. At rush hour that's easily 2 hours each way.

buglawton

almillar wrote: »

You're just ignoring the rest of the discussion, then, about destination chargers, charging at work, whilst shopping etc? There will be a premium at rapid chargers because of their key locations, and speed. You choose to ignore the cheaper and free chargers. Do you buy your petrol at a motorway service station too, or do you avoid it because it's expensive?



OK, answer me a question - how often do you think an EV needs to charge - hint, it's not necessarily every night! Are you grossly overestimating the time taken to charge? As a very rough guide, 30 mins at a rapid would give, say, 60 miles of driving. 2 hours at a standard 7kW one would give, say, 50 miles. That would get me to work and back home a few times.

The reality is that around here there are long Victorian streets with no driveways and narrow pavements. Everyone, even if resident permit holders, jostles for a parking spot and once parked will not budge because there's no other on street parking for a mile radius.

I could imagine that one day every single parking bay of supermarkets will have a fast charging point that's compatible with all EVs. The charging equipment will need to be underground of course, there's simply no room in current layouts.

I could imagine it but think we're looking at 2090.

Herzlos

buglawton wrote: »

The reality is that around here there are long Victorian streets with no driveways and narrow pavements. Everyone, even if resident permit holders, jostles for a parking spot and once parked will not budge because there's no other on street parking for a mile radius.

I could imagine that one day every single parking bay of supermarkets will have a fast charging point that's compatible with all EVs. The charging equipment will need to be underground of course, there's simply no room in current layouts.

I could imagine it but think we're looking at 2090.

The thing is that not every bay in every single car park needs to have a fast charging point, because not everyone will need to fast charge. Maybe something like 1 in 10 would be sufficient, potentially also something like another 2 in 10 being slow chargers.


Current cars on current annual mileage need charged once a week. They can do that piecemeal on slower chargers or they can spent half an hour on a fast charger somewhere.


Absolute worst case is that they need to go into a charging station and have a coffee once a week, but the reality is that most people will be able to charge their cars whilst going about their weekly errands for no additional inconvenience and without turning every parking space into a charging point.

buglawton

Back to reality again: Both supermarkets nearest me have car parks that are close to 100% full at popular times. So how will 1 in 10 spaces having a charging point work then? No, there'll have to be 1 per bay.

Herzlos

buglawton wrote: »

Back to reality again: Both supermarkets nearest me have car parks that are close to 100% full at popular times. So how will 1 in 10 spaces having a charging point work then? No, there'll have to be 1 per bay.

Put the charging bays at the back so that only the people who need to charge will use them.
Make it an offense to park in a fast charger when not charging.

You're highlighting a social problem and not a technical one; less than 10% of the cars in any given supermarket car park will need to charge at that point in time.

Martyn1981

buglawton wrote: »

The charging equipment will need to be underground of course, there's simply no room in current layouts.

I could imagine it but think we're looking at 2090.

The UK already has lampost charging.

Whilst induction charging is not yet ready, it has already reached levels of efficiency into the 90%'s.

Also we are seeing a resurgence of battery swops / battery leases in China.

So I doubt we'll have to wait till 2090.

buglawton wrote: »

Back to reality again: Both supermarkets nearest me have car parks that are close to 100% full at popular times. So how will 1 in 10 spaces having a charging point work then? No, there'll have to be 1 per bay.

In reality, can you confirm that 100% of the spaces are supersized for disability use/access?

DrEskimo

buglawton wrote: »

The reality is that around here there are long Victorian streets with no driveways and narrow pavements. Everyone, even if resident permit holders, jostles for a parking spot and once parked will not budge because there's no other on street parking for a mile radius.

I live in a victorian terraced with no parking (in fact it's single yellow outside my door) and I plan to get an EV.

I sold my car over 18months ago and since I commute to London I have been managing just fine with sharing my OH car. My only miles driven are Sat when out and about, and Sunday when I visit my family. Probably 50miles a week in total. My plan was to get an EV charger installed at my parents and just top it up for the hours I am there. Alternatively there is a free charger at Tesco, and a rapid charger that costs just £1 for access.

My OH has a small petrol Mini that she uses for her 15mile round commute to work. So even if she used the EV and we parked the Mini to save on fuel, it would only do about 125miles a week. 40kWh Zoe would handle this just fine with only a weekly charge. 60kWh Kona could possible do it every other week!

With larger capacity batteries, and short commutes that allow for periodic charging, there are plenty of options for EV ownership even without direct access to home charging. Not to mention the fact that my house is only 2 bed, so will likely move in the next year or so to somewhere where we can charge at home.

almillar

The Kia Soul is more pricey than the Zoe like for like but it is a nicer car.

I'd take a 40kWh Zoe over a 30kWh Soul, but the Soul was far cheaper when I bought - DriveElectric is/was far cheaper than the Kia prices. Happy to take a referral fee if anyone buys!

How long does it take to charge your car after a commute at 7kW? I'm assuming it's closer to 2 hours (£2.10) rather than the 8 hour business day?.

Exactly, I gave the worst case, charging all day.

I said "ultimately unsustainable", and assumed that the implicit "once a substantial proportion of the employees drive EVs" would be understood.

Yes, it kind of was. I'm not talking about having a charger for every car though. Many employers don't even provide parking, never mind charging. So it's a perk. And 3 charging spaces in a car park IS sustainable in my opinion. More EVs might be driven, you might charge in the morning and swap with a colleague at lunch time. If there's a night shift the spaces might be quieter too. That's sustainable. Maybe staff will start fighting over the spaces, that's about the only problem I can see.

If there's 20 chargers

That would be great! Remind me, how many ICE cars get filled up whilst an employee is working? I could cope with a rota system, and in your example, that would be 40 cars per day getting a charge (swap at lunch). Parking at work is a privilege for many, not a right, and charging would be similar.

£8.40 a car - where did you pluck that figure from?

He got it from me - post #2742, and multiplied it up to the absdolute maximum usage possible within 8 hours. That would be 20 40kWh Zoes turning up empty every day.
Whilst we're poking at the numbers, not all cars can even take 7kW AC - original LEAFs are at 3.3kW unless they're upgraded, and many other cars are at 6 or so.

You may have commuted more than 75 miles each way but that's hugely atypical

I may have mentioned to Adrian a few times before that he's 'abnormal'!

The reality is that around here there are long Victorian streets with no driveways and narrow pavements. Everyone, even if resident permit holders, jostles for a parking spot and once parked will not budge because there's no other on street parking for a mile radius.

I asked you a question - you did not answer it. And to answer your question, chargers can be fitted to lampposts. Next problem?...


Just a general point that may help out - Electric cars don't have to charge overnight, every night. They don't have to be at 100% at the start of every journey. It's possible to charge once or twice a week (me).