The EV fact thread

[BTB 500]

Regarding EV charging, there are many ways of managing it, again it's all down to data collection and software.

For example, not only could there be a different tariff for charging during off-peak time (which - as said - does not have to be nighttime - it can change dynamically), but also for charging speed - i.e. you could pay (say) 2p per kW if you set the charging speed of your home charger to 3kW, or (say) 25p if you set it to the maximum possible (7kW or 11kW or whatever it might be). That's a great way of managing demand.

But if your car is only at home overnight (which will be the case for much of the working population) there will always be a peak in demand then ... variable pricing won't be able to change that?

In fact, you could even instruct the software to 'charge at (say) 5p per kW', and the charger will adjust the speed and time of charging accordingly.

Octopus Energy already do something similar:

Connect your EV or charger in the Octopus app

Then, just plug in your car and tell us how much charge you need. We'll automatically schedule your charge for when energy is cheapest and greenest, and you'll only pay 7p/kWh regardless of the time of day.

You need a compatible charger of course.

I can see this being useful with the current 3% or so of UK vehicles being BEV, but as above it will surely be rather more tricky when we are close to 100% and the overnight peak is orders of magnitude larger.

Isn't another fundamental issue the loss of the gas-fired power stations that have traditionally been used to meet peaks in demand (because they can be started/stopped very quickly)?

 

[BTB 500]

Yes, you don’t understand how chargers work, this is clear. Why would I, or anyone else, have a stream of vehicles charging at top speed?

Why would Tesla (and others?) be building sites like that on main routes if there was no need for them?

here’s the detail of the 10MW site in Oxford, the biggest in Europe, which has the capacity to charge up to 400 vehicles, using 10MW “if” it was ever needed.

Europe’s most powerful EV charging hub officially launched as part of Energy Superhub Oxford - EDF Renewables

www.edf-re.uk

Quote from that page:

Unlike any other UK charging hub, the site is directly connected to National Grid’s high voltage transmission network via a four-mile underground cable, which will deliver 10 MW of power to quickly and simultaneously charge hundreds of EVs without putting additional strain on the local electricity network or requiring costly upgrades.

Interesting in the context of Tesla sites that are also claimed to provide 10 MW.

 

[ChipChop]

Yes, you don’t understand how chargers work, this is clear. Why would I, or anyone else, have a stream of vehicles charging at top speed?

“If” I bought a couple of EVs to do my 12,000 miles a year, I could comfortably keep them topped up on a three pin plug, apart from maybe a dozen times when I’d need a short, slow top up while away from home.

As you don’t know what a 10MW high volume site looks like, here’s the detail of the 10MW site in Oxford, the biggest in Europe, which has the capacity to charge up to 400 vehicles, using 10MW “if” it was ever needed.

Europe’s most powerful EV charging hub officially launched as part of Energy Superhub Oxford - EDF Renewables

www.edf-re.uk

Did you read the link you posted? The 10MW site in Oxford has the capacity to charge up to 400 vehicle.

That figure is assuming 350 cars charging at the snails pace of 7kW and 50 cars charging at 150kW. Your three pin plug at home charges at 2.3kW by the way.

Tesla V3 & V4 superchargers deliver 250kW consistently between 10-80% SOC according to this forums Tesla brethren. The very latest evolution of superchargers at the even higher rate of 350kW.

 

[MikeInWimbledon]

Why would Tesla (and others?) be building sites like that on main routes if there was no need for them?




Quote from that page:



Interesting in the context of Tesla sites that are also claimed to provide 10 MW.

It’s a site being built on a motorway artery to serve people popping down to the Excel from the North West for the day, who need to stop for 15 minutes to add 200 miles to their range

These sites aren’t intended, or needed for routine domestic charging

Do you have some examples of these Tesla sites in the Uk that claim to have 10MW charging? That would be Tesla sites with typically 100+ chargers.

 

[MikeInWimbledon]

Did you read the link you posted? The 10MW site in Oxford has the capacity to charge up to 400 vehicle.

That figure is assuming 350 cars charging at the snails pace of 7kW and 50 cars charging at 150kW. Your three pin plug at home charges at 2.3kW by the way.

Tesla V3 & V4 superchargers deliver 250kW consistently between 10-80% SOC according to this forums Tesla bretheren. The very latest evolution of superchargers at the even higher rate of 350kW.

Of course I read it. Clearly you didn’t understand it. It’s “up to 400 vehicles” because there’s nowhere near the demand expected any time soon. When did you last see a petrol station with 400 pumps in continuous operation? Cobham on the M25 used to be the biggest with just 35 pumps. Just 35 !

You won’t need to charge your EV at the rate of 750+ miles per hour connected. That e-Golf can only peak at 50kwh, which is more than its owner needs. She’s more likely to top it up at a 22kwh connection in a car park, or outside her office or workshop.

 

[BIGDOG]

Why would Tesla (and others?) be building sites like that on main routes if there was no need for them?




Quote from that page:



Interesting in the context of Tesla sites that are also claimed to provide 10 MW.

What makes you think that you know better than the guys on here who own an EV and live with them day in day out?

 

[ChipChop]

Of course I read it. Clearly you didn’t understand it. It’s “up to 400 vehicles” because there’s nowhere near the demand expected any time soon. When did you last see a petrol station with 400 pumps in continuous operation? Cobham on the M25 used to be the biggest with just 35 pumps. Just 35 !

You won’t need to charge your EV at the rate of 750+ miles per hour connected. That e-Golf can only peak at 50kwh, which is more than its owner needs. She’s more likely to top it up at a 22kwh connection in a car park, or outside her office or workshop.

I refer you to the forums resident Tesla owner...

Even with V3/V4 sites being full I have always got the max power output. The sites have sufficient power supplies but if this isn’t possible they are supported by ‘Mega Pack’ batteries for peak use.

Sorry Rob, yes I mean when I’m between 0% to say 40% I get the max output, naturally as the SOC increases the max output tapers. This is why you don’t ever really fill up above 80-100% on a fast charger as it’s just a waste of time. I usually just go from 5%-80% in say 30 mins.

The reply was mainly aimed at the point that even at a full site you can get the theoretical max output across all stalls with the cars being at the right conditions.

Max output for V3/ V4 superchargers is 250kW. See below.

https://www.tesla.com/en_gb/support/charging/supercharger

 

[BTB 500]

Do you have some examples of these Tesla sites in the Uk that claim to have 10MW charging? That would be Tesla sites with typically 100+ chargers.

Posted by a Tesla owner in this thread:

There is no standard number of stalls per site, as it depends on location demand and space availability. Small sites may have as few as 6–8 stalls, often in rural or low-traffic areas. Larger sites, especially along motorways, may have 20–40 stalls. For example South Mimms on M25 has 36, Exeter on the M5 has 32 etc…

A site with forty 250 kW stalls that could all deliver the full rated power simultaneously (as claimed) would require 10 MW.

 

[BTB 500]

What makes you think that you know better than the guys on here who own an EV and live with them day in day out?

Like the owners who didn't know about charging losses, for example?

I don't have an EV but I've built and used electric drive systems with Lithium batteries on a much smaller scale for almost 25 years now so I have a reasonable understanding of the basics.

 

[markjay]

But if your car is only at home overnight (which will be the case for much of the working population) there will always be a peak in demand then ... variable pricing won't be able to change that?

Some incorrect basic assumptions there...

Firstly, not everyone works 9-5 outside their home. Many people work from home and never go to the office, some go the office two or three days a week, others work shifts, and many don't even use their cars for commuting to work. So charging patterns will vary considerably.

Then, the vast majority of people will not need to charge their EV every night (even if they do work 9-5 away from home, every day). A 200 or 300 mile daily commute to work is extremely rare. .

And last, even for those few who work 9-5 outside their homes, and need to charge their cars every night... there are 12 hours betwen 6pm and 6am, the charging of the various cars can be staged to avoid everyone charging between 6pm and (say) 12pm.

Also, keeping in mind the most people will only top-up rather than charge zero to full - in my use case, had I driven to work even day I would only need to charge once a week, from 50% to 80%.

The famous 'kettle' scenario during the TV football match break simply does not apply to EVs.

 

[MikeInWimbledon]

it’s 5pm on a Winter’s evening let’s check the biggest Tesla charging site in the UK. 38 chargers at Moto Exeter.

And how many 350kwh chargers are free ? Is there a queue?

That’ll be 28 chargers free. No queue

 

[BTB 500]

Some incorrect basic assumptions there...

Firstly, not everyone works 9-5 outside their home. Many people work from home and never go to the office, some go the office two or three days a week, others work shifts, and many don't even use their cars for commuting to work. So charging patterns will vary considerably.

Sure, but I suspect a significant majority of workers across the UK still have a conventional '9-5' or so working day (say 8-6 away from home) - hence a rush hour twice a day? Of course plenty of rail commuters use their car to get to a station, so it can't be charging at home during the day.

Then, the vast majority of people will not need to charge their EV every night (even if they do work 9-5 away from home, every day).

Of course. But one in five of 42 million EVs being charged on any given night will still cause a pretty sizeable peak.

there are 12 hours betwen 6pm and 6am, the charging of the various cars can be staged to avoid everyone charging between 6pm and (say) 12pm.

As I understand it home charging from a normal single-phase domestic supply is limited to 7.3 kW from a wall box? So you could be looking at up to 10 hours to charge say a 70 kWh battery, depending on losses and how full it was to start with. From a domestic 3-pin socket charging is generally limited to 10A I think, so 2.3 kW. Hence a full 12 hours of charging would only give you 23 or 24 kWh after losses. Not much scope for staging there.

 

[Dryce]

Of course I read it. Clearly you didn’t understand it. It’s “up to 400 vehicles” because there’s nowhere near the demand expected any time soon. When did you last see a petrol station with 400 pumps in continuous operation? Cobham on the M25 used to be the biggest with just 35 pumps. Just 35 !

It's really about density of recharging capacity.

So get out the back of the envelope ....

I charge my car at about 600 miles in under 3 minutes.

If I had a more economical car it would probably have a smaller tank and probably under 2 minutes.

So 35 pumps - let's say 4 minutes per pump at 3 mins plus 1 min get in and out - then that's say 525 cars per hour.

You won’t need to charge your EV at the rate of 750+ miles per hour connected. That e-Golf can only peak at 50kwh, which is more than its owner needs. She’s more likely to top it up at a 22kwh connection in a car park, or outside her office or workshop.

So 10MW of supply rate - 40 charging stations - each car charged at an average or 250kW - so charge say 50kWh per car - so 12 minutes plus 1 minute in/out - that's 185 cars per hour.

Now you can play with the numbers - some cars might charge slower - some might take less. The setup time might be a bit more. Some drivers will take an inordinate amount of time to get in and out and pay.

I'm guessing that in practical terms an installation with 40 charging bays probably don't take up more than 35 pumps and vehicle bays.

Anyway - the scribblings on the envelope suggest in a given area of a services that the recharging density of ICE vs EV might be 2.8 though if EVs are charging at a lower rate or it could be a lot more.

 

[markjay]

....Of course. But one in five of 42 million EVs being charged on any given night will still cause a pretty sizeable peak...

Correct, assuming that in 2050 the UK energy production and distribution system will still be exactly the same as it is today... and that EV charging technology has already peaked

I suppose it could have been predicted back in 1995 that the Internet won't work, because if every business and household bought a Hayes 56k modem, then we'll need to double the number of analogue PSTN copper lines in the UK, and BT would say that it couldn't be done. Who could have predicted back in 1995 the emergence of new technologies such as ADSL, FTTC, and FTTP? Let alone Starlink?

Again, there are two mistakes being made here: the first is extrapolating on current technology decades ahead into the future, and the second is assuming that EVs are driven and charged like ICE cars.

 

[markjay]

As I understand it home charging from a normal single-phase domestic supply is limited to 7.3 kW from a wall box? So you could be looking at up to 10 hours to charge say a 70 kWh battery, depending on losses and how full it was to start with. From a domestic 3-pin socket charging is generally limited to 10A I think, so 2.3 kW. Hence a full 12 hours of charging would only give you 23 or 24 kWh after losses. Not much scope for staging there.

Again... EVs are not typically charged from zero to full, like you might do with an ICE car.

Those people who do work 9-5, every day, and commute to work using their EV, every day, will either top up 10-20kW (that's 30-60 miles in average conditions) at night every day.

Even if they do insist on driving their EV like a petrol car, they'll still only need to 'fill-up' every weekend at most.

Those driving only to the nearest train station car park will probably top-up single-digit kW every night (or zero to full every 3-4 weeks).

The scenario where a car needs 70kW of charge every night is only applicable to cars driven 200 miles every day. Sure, some do that... but most don't.

What will happen in real life is that for those with a drive and a changer, it will be a non-issue. You'll get home, lock the car, plug it in, and just forget about it. You'll let the computers do the job and work out the optimal charging regime. In fact, your life will be much easier - if you use the car to commute daily to work - because you never have to worry about filling up again. If planning a long journey during the weekend... you'll just need to let the car know. The computer will sort it out for you.

That's the reality that our grandchildren will be living in. Actually, with AI, things will most likely be even more exciting.

 

[BIGDOG]

Like the owners who didn't know about charging losses, for example?

I don't have an EV but I've built and used electric drive systems with Lithium batteries on a much smaller scale for almost 25 years now so I have a reasonable understanding of the basics.

Seriously?

You cannot be comparing toys to EV infrastructure and car design.

 

[markjay]

....So 10MW of supply rate - 40 charging stations - each car charged at an average or 250kW - so charge say 50kWh per car - so 12 minutes plus 1 minute in/out - that's 185 cars per hour....

I am not an electrical engineer, but I am assuming that it's similar to how comms network work.

The 'bandwidth' figure that you see is (in most cases) not dedicated. There are things called 'burst mode' and 'dark fibre', managing demand.

Similarly, there's no need to be able to provide full capacity to all chargers at the same time.

I would hazard a guess that 20 stalls with 250Kw capacity will not need a 5kW supply. More like around 3-4kW supply will do.

This is because a scenario of 20 cars charging at 250kW is not only unlikely, in fact it's impossible.

Firstly, not all cars are capable of charging at the highest speed. Then, the highest charging speed is only achieved with a warm battery, and so some cars will start slower until the battery has warmed up. Then, cars being charged beyond the 80% limit will slow down the charging. And last, out of 20 cars, some will be at various staging of parking up and getting ready to connect, while others will be busy disconnecting and driving out of the bay. In fact, 20x250kW will never ever happen.

I am willing to bet that the trunk capacity to these charging hubs is less than the total nominal capacity - it just doesn't make sense to design it any other way (unless you over spec the trunk supply in order to support future expansion and future upgrades).

 

[Bobby Dazzler]

When does the unseen mega user of power, AI, choose to consume? At random? AI acts without human intervention so it creates its own power requirements. Its own demand peaks and troughs. The environmental impact of energy consumption applies only to humans not data centers it appears.

I sense future threads on AI. It’s one of those topics.

 

[Bobby Dazzler]

Elon Musk knows that... which is why he is so keen of having good commercial relationships with China.

The Japanese time bomb was diffused in the eighties by agreements that saw Japanese cars being assembled in Europe and the US (sometimes under local brand names), and Japanese components fitted in domestic cars.

I wonder what will happen with China? It should be in China's interest to come to some agreement with the West. If they just flood the West with cheap EVs subsidised by the Chinese government via the CDB, it will 'end in tears' with the US and EU and UK putting up high tariffs on Chinese EVs to protect domestic jobs.

In the meantime, Korean brands are establishing themselves as the high-quality Far Eastern alternative to the Chinese.

Nissan started manufacturing in Europe for this reason, and specifically Sunderland as it came with the greatest incentives. A few decades later and Nissan in Sunderland is considered domestic in the context of this thread, despite having started out as a threat.

If the same cards are played by the West then something similar is a possibility.

 

[Bobby Dazzler]

Did you read the link you posted? The 10MW site in Oxford has the capacity to charge up to 400 vehicle.

That figure is assuming 350 cars charging at the snails pace of 7kW and 50 cars charging at 150kW. Your three pin plug at home charges at 2.3kW by the way.

Tesla V3 & V4 superchargers deliver 250kW consistently between 10-80% SOC according to this forums Tesla brethren. The very latest evolution of superchargers at the even higher rate of 350kW.

You’re a resourceful fellow so I bet you’ll be able to find out how long on average a car is parked in a park & ride car park.

My guess would be most of the working day. If my guess is even close to reality then would those cars need to be charged at more than a snail’s pace?

Not all cars will even need to be charged so charging 350 at snails pace plus 50 at lightning speed plus umpteen not charging at all sound right.

Plus of course all of those HFC, hybrid and ICE vehicles which will also park at the park & ride and won’t be replaced for years to come.