AC vs. DC fast charge

[Kane]

Zoo, themepark, etc within 50km? Make it at least 150km.

Destination charging with 3-phase 16A (11kW) makes a lot of Sense!

The 'Efteling' (themepark in NL) recently started to offer charge points.

You'll be in a themepark or Zoo for a couple of hours, with 11kW you can fill up a lot.

I only see a case for DC if and when it is really high power and I want to drive beyond the range of my battery in a single trip.

I'm not saying 11 kW is not usable . Only that it's not economical for public use (it can be economical in private use when you using it often and not paying premium for electricity).

3 hours of 3.3 kW will replenish about 50% of typical battery pack.

I will ask You something. Will You pay for 11 kW charging every day in Ecotality, GCC, or other firm plan? Ecotality cheapest tarif is now $1/hour of charging (with power over 3.3 kW it is probably higer and max over 7 kW) plus $30/a year. Will you pay it every day - in every shop/work/zoo parkings? Or You want it "free"?

Eledille says "DC charging will get old quickly". He doesn't mean the battery will age, he means you will soon get bored of standing/sitting around waiting for even a 15-30 min fast charge as opposed to plugging in at home or at your destination and then instantly walking away from the car. I agree 100%.

Sorry, I read it wrong .

AC 43 kW have the same problem when you going far and must stop.

 

[widodh]

I'm not saying 11 kW is not usable . Only that it's not economical for public use (it can be economical in private use when you using it often and not paying premium for electricity).

3 hours of 3.3 kW will replenish about 50% of typical battery pack.

I will ask You something. Will You pay for 11 kW charging every day in Ecotality, GCC, or other firm plan? Ecotality cheapest tarif is now $1/hour of charging (with power over 3.3 kW it is probably higer and max over 7 kW) plus $30/a year. Will you pay it every day - in every shop/work/zoo parkings? Or You want it "free"?

This contradicts what you said earlier.

I don't see why you use 3.3kW again as the example while I was talking about 11kW.

That also works in public and is not expensive, a themepark won't notice a 11kW draw on their total usage. They will probably offer it for free.

In NL you can already charge with 11kW alongside the public road, you pay per kWh. Depending on the supplier you choose it is about 23c/kWh. Not that bad.

Charging away from home will always be more expensive.

 

[Kevin Sharpe]

That also works in public and is not expensive, a themepark won't notice a 11kW draw on their total usage. They will probably offer it for free.

I completely agree with you.

We have installed almost 200 locations in the UK and many can easily support multiple 22kW or 43kW Charging Stations. The vast majority of sites have no plans to charge for electricity because the EV driver will be using some other service (eat, sleep, play, park, etc).

The amounts of power we are talking about are trivial for many commercial locations... we've just been offered multiple 125A 400V (~86kW) feeds by one location for our June EVent

 

[jcstp]

In England there is an exeption, there is a network where all slowcharging is at destinations, and free

(if you think 32A is slow)

 

[Kane]

This contradicts what you said earlier.

I dont' think so.

I don't see why you use 3.3kW again as the example while I was talking about 11kW.

Because I wanted to illustrate that 3,3 kW is enought in situation where you stay somewhere for few hours.

Charging away from home will always be more expensive.

Right. And majority of people will not use more expensive charging if not need it to back home.

In England there is an exeption, there is a network where all slowcharging is at destinations, and free.

On the begining also DC charging in many areas is free. But nothing is realy free (price will be just hidden in other products). You can also do free DC at fast food. This is not valid argument in AC vs. DC.

 

[Kevin Sharpe]

Because I wanted to illustrate that 3,3 kW is enought in situation where you stay somewhere for few hours.

I don't think so... for example, this week I charged for three hours while attending a meeting. During that time I gained ~75 miles extra range charging at ~7kW (32A single phase). If I had charged at ~3kW (16A single phase) I could not have made the trip after my meeting.

I undertake a lot of trips and look forward to the time that my Roadster supports ~16kW charging from three phase because that will transform my driving in the UK and most of mainland Europe.

 

[Kane]

I don't think so... for example, this week I charged for three hours while attending a meeting. During that time I gained ~75 miles extra range charging at ~7kW (32A single phase). If I had charged at ~3kW (16A single phase) I could not have made the trip after my meeting.

I undertake a lot of trips and look forward to the time that my Roadster supports ~16kW charging from three phase because that will transform my driving in the UK and most of mainland Europe.

Someone said that he will be 5 hours in zoo and want 11 kW. I was talking that 3 hours of 3,3 kW will replenish about 50% of SOC (in typical EV with about 20 kWh pack). Now someone else talking about meeting and other type of car. It's hard for me to talk with different people about different situations at once in one topic.

I just presented arguments and some calculations AC vs. DC (in scale of milions). Do some calculations and show us that AC is better because talking about single case does not make sense. We are on the begining of the new world and we must wisely choose good solution for public charging - that not only works but is cheper (in big scale). For me important are total costs (in car, AC point, utility monthly cost, efficiency drop, prices, etc). I think that DC is better.

About 98% of electric and plug-in cars on the roads (almost 150 000) have on-board charger with output no higher than 3,3 kW (higher AC power is useless for them). About half of them (and over 75% of EVs) have DC inlet for 50 kW. Only 75% mainly because standards war (SAE/IEC vs. CHAdeMO).
We have 0 cars with 43 kW AC, and maybe 100 (optional smart from october) with 22 kW AC 3-phase, plus maybe 3500 (Roadsters, Tesla, MINI E) with 10-20 kW range single phase.

AC networks are dead already. Time usage of leading ChargePoint network is under 0,3%. But they are typicaly 7,2 kW (30 A) so the time/power usage is under 0,15%. What will be the usage of 22 or 43 kW? Show me the numbers, not your individual case.

 

[widodh]

The problem imho lies with the deployment.

A lot of people who deploy a EVSE deploy a 3.3kW one since they have no idea of the other opportunities.

I really do think there is a market for AC in public when it's at least 3x16A.

In the future we will see more cars with 3-phase chargers on board, mainly from the Germans.

 

[Kevin Sharpe]

AC networks are dead already.

You might like to mention that to the French... at a recent SMMT meeting a French delegation told us about Government plans to deploy one million AC Charging Stations within five years.

It's also clear that UK Government policy is to deploy AC Charging Stations which was reaffirmed at a recent meeting I had with OLEV and the Parliamentary Under Secretary of State for Transport, Norman Baker MP.

- - - Updated - - -

In the future we will see more cars with 3-phase chargers on board, mainly from the Germans.

I've also seen prototype 3 phase chargers for the Leaf from an aftermarket company... personally I think 3 phase will be very widespread in Europe.

 

[GSP]

Someone said that he will be 5 hours in zoo and want 11 kW. I was talking that 3 hours of 3,3 kW will replenish about 50% of SOC (in typical EV with about 20 kWh pack). Now someone else talking about meeting and other type of car. It's hard for me to talk with different people about different situations at once in one topic.

I just presented arguments and some calculations AC vs. DC (in scale of milions). Do some calculations and show us that AC is better because talking about single case does not make sense. We are on the begining of the new world and we must wisely choose good solution for public charging - that not only works but is cheper (in big scale). For me important are total costs (in car, AC point, utility monthly cost, efficiency drop, prices, etc). I think that DC is better.

About 98% of electric and plug-in cars on the roads (almost 150 000) have on-board charger with output no higher than 3,3 kW (higher AC power is useless for them). About half of them (and over 75% of EVs) have DC inlet for 50 kW. Only 75% mainly because standards war (SAE/IEC vs. CHAdeMO).
We have 0 cars with 43 kW AC, and maybe 100 (optional smart from october) with 22 kW AC 3-phase, plus maybe 3500 (Roadsters, Tesla, MINI E) with 10-20 kW range single phase.

AC networks are dead already. Time usage of leading ChargePoint network is under 0,3%. But they are typicaly 7,2 kW (30 A) so the time/power usage is under 0,15%. What will be the usage of 22 or 43 kW? Show me the numbers, not your individual case.

Your total cost analysis for the long term case (posted earlier) when there are tens of millions of EVs deployed, and perhaps hundreds of thousands of public charging points, looks valid to me, and favors DC as the best value solution. Thanks for sharing it with us.

However in the near term case there will not be very many EVs deployed, but tens of thousands of public charging points will still be needed to provide their owners with the autonomy a gas or diesel car provides. The best bet for these early EV adopters will be for them to bear the cost of the charger, and reduce the cost of the lightly used (and more numerous) charging points as much as possible. This makes it easier to convince property owners to install charging points, which is critical at this point in history. Low cost AC charging points can even be donated to property owners to help convince them to install and maintain them. This is a brilliant strategy, as I am sure Kevin Sharpe and ZCW will agree. :smile:

My prediction is that AC will be more popular at first, then after a few million EVs are deployed DC will become more popular. Both will coexist. Also, EVs will continue to have 3-11kW chargers for home charging for a long time, at least a few decades.

GSP

 

[eledille]

I drive an EV every day. When I park it at any one of my local shopping centers in Oslo, I get a reserved EV parking spot with a 3.6 kW outlet. There is one particular shopping center I refuse to use, because they do not offer charge points there.

The price of a single indoor parking spot in Oslo is approximately 400 to 450 euro per month, or 4800-5400 euro per year. They can be equipped with a non-weatherproofed, non-vandalproofed three phase outlet, because they are indoors and under camera surveillance. Electricity, even at 11 kW, is worth very close to nothing compared to the business they generate, about 1 euro per hour in Norway, maybe two euro elsewhere in Europe. When I'm at a shopping center, I'm certainly spending money at a much higher rate than that. For a rented parking spot, the price is easily included in the rent, so you don't need any payment system in that scenario either. The real cost of such a charge point is on the order of 500 to 800 euro.

I, as an EV owner for the last six years, swear that I will not replace weekly ten-minute stops at the gas station for hours of waiting at a quick-charger. I want to go somewhere and have the car charge unattended while I'm going about my business, or on longer trips, while I eat my lunch and get some rest.

People are talking about how it's cheaper to share a few quick-chargers than give everyone their own lower-powered outlet, but this is less attractive for the very same reason that causes us to own and pay for cars in the first place - you don't want to wait, you don't want to share, you don't want to figure out where the bus stop is or when the bus arrives. You want the convenience of just getting behind the wheel of your own car and go. For my gasoline powered car alone I'm paying around 8000 euro per year in depreciation, fuel, insurance, taxes, tolls, service and repairs for that privilege.

In the same way, I don't want to queue at a quick-charger, I don't want to figure out where the thing is or go out of my way to get there. I just want to drive to my destination and plug in.

Very, very occasionally, I might drive at high speed along a motorway for hours. In this case, I might want to quick-charge, but then I don't want just fifty lousy kilowatts, I want at least a hundred. With an 85 kWh battery (which is the one we're getting), I would still have to charge for 45 minutes, which is much too long when you're just waiting.

Destination and home charging are the only quick and pain free ways of charging EVs. Unless Renault is a bunch of unscrupulous liars, this has been proven to be possible at incredibly low cost, and it is in my not too humble but experienced opinion obviously much more attractive than sharing much fewer expensive DC chargers. You will have to queue. You will have to wait. You will have to go out of your way to get there, except when on the motorway. Sometimes, they will be broken when you counted on them, with no backup in the vicinity.

I cannot fathom why DC attracts EV newbies like honey attracts wasps, particularly as 50 kW DC is only 15% more than 43.6 kW AC, and AC is not competing against 75+ kW DC anyway.

 

[jkirkebo]

AC networks are dead already. Time usage of leading ChargePoint network is under 0,3%. But they are typicaly 7,2 kW (30 A) so the time/power usage is under 0,15%. What will be the usage of 22 or 43 kW? Show me the numbers, not your individual case.

Oslo, Norway has around 1000 AC charge points. On a typical day, between 8am and 3pm, most of them are in use and the big lots (36-50 charging spaces) are always full. However, nearly all of these are only 3,7kW (230V 16A) and are mostly used by people at work or at home (apartments with street parking). A few are at destinations like shopping malls, IKEA etc, but not many.

Hopefully we will get some 7,4kW, 11kW and 22kW soon as 3,7kW is not enough to refill a Model S during a typical work day.

 

[stopcrazypp]

People are talking about how it's cheaper to share a few quick-chargers than give everyone their own lower-powered outlet, but this is less attractive for the very same reason that causes us to own and pay for cars in the first place - you don't want to wait, you don't want to share, you don't want to figure out where the bus stop is or when the bus arrives.

I think that's the key point. Sure economically, having lots of low powered outlets costs more than sharing a quick charger, but the barrier to entry is a lot lower for low powered outlets. As a unit, they cost less to install, they can be installed virtually everywhere, the owner doesn't have to worry about paying extra demand charges (for drawing at high power) and rarely do they have to upgrade wiring. Even if the utilization rate of them is very low, it's doesn't really matter because the amount of money sunk into each one is relatively low (although as a network it can be quite costly).

So I think in the future for privately owned (not owned by a large charging network) nightly charging and shopping areas it'll still be low power AC. DC will be for longer trips and large charging networks will probably increasingly use them (as we finalize the DC standards and batteries are more durable and can use them daily).

 

[eledille]

I think that's the key point. Sure economically, having lots of low powered outlets costs more than sharing a quick charger, but the barrier to entry is a lot lower for low powered outlets.

Exactly, and the cost can be absorbed over many years as the market share of EVs increase, one or two or five charge points at a time.

But keep in mind that if you want 80% utilization of a quick-charger, then there is an 80% probability that someone will be charging when you arrive. How long will the queue be at 16:00 on a weekday?

The following is seen from a European perspective, in markets where three phase is less available, the numbers may work out differently.

44 kW isn't low power. A 50 kW charger takes 1:22 to do a 10-90% recharge of an 85 kWh battery, while a 43.6 kW charge point would take 1:34. The difference isn't large, and 3-phase AC has the enormous advantage of compatibility with less expensive and lower power (but still quite powerful) 11 and 22 kW charge points.

I'm all for DC supercharging, but that is a completely separate issue. DC at 70+ kW and AC complement each other, and I would like to see both succeed.

 

[eledille]

Efficiency drop with partial load not happen with the motor drive? OMG. No comment.
I bid that charging at home about 3-5 kW 1-phase or 11 kW 3-phase with inverter rated on 65 kW will drop efficiency by even 3-5%.

Quote from this link: "To conclude, one of the main benefits of fitting a variable speed drive is that for all conditions of running load, drive system efficiency will be typically 96-97% and power factor will be approaching unity, resulting in electricity savings by a reduction in kWHr consumption."

Very high partial load efficiency is one of the main reasons that diesel-electric propulsion systems are so popular. A VVVF motor drive is very similar to a rectifier/DC voltage regulator, but more complex - it contains a DC to three phase AC inverter instead of a DC/DC voltage regulator for the output. I can't see why the 3~ rectifier/DC voltage regulator would be so much less efficient at partial load than the 3~ rectifier/3~ inverter.

If it really is so inefficient, then I would love to know why.

 

[Kevin Sharpe]

I spent two hours this morning talking at the accommodation providers annual general meeting in my small town. At the end of the meeting six locations agreed to install AC Charging Stations for visitors and one (near a busy road) expressed interest in installing 43kW AC for attracting drivers to their restaurant.

Large scale deployment of AC charging is easy and will be undertaken en masse by existing businesses.... if we keep the hardware simple, reliable, and low cost then everyone will install.

 

[eledille]

Large scale deployment of AC charging is easy and will be undertaken en masse by existing businesses.... if we keep the hardware simple, reliable, and low cost then everyone will install.

 

[Bipo]

I'm all for DC supercharging, but that is a completely separate issue. DC at 70+ kW and AC complement each other, and I would like to see both succeed.

That's the point. Both AC and DC may coexist, but each one for their logical use: DC for ultrafast charging (over 80 kW) and AC for everything else (including 43 kW fast charging).

 

[Kane]

You might like to mention that to the French... at a recent SMMT meeting a French delegation told us about Government plans to deploy one million AC Charging Stations within five years.

Ok. We have some new confirmation:
- PSA will introduce two new models this spring-summer Peugeot Partner Electric and Citroen Berlingo Electric with slow AC about 3,5 kW and CHAdeMO DC fast.
So, even French manufacturer not sharing Renault 3-phase 43 kW on-board charging system (someone earlier told us that they will share their brilliant idea with other manufacturers) and will not utilize this high power AC outlets .

 

[eledille]

Ok. We have some new confirmation:
- PSA will introduce two new models this spring-summer Peugeot Partner Electric and Citroen Berlingo Electric with slow AC about 3,5 kW and CHAdeMO DC fast.
So, even French manufacturer not sharing Renault 3-phase 43 kW on-board charging system (someone earlier told us that they will share their brilliant idea with other manufacturers) and will not utilize this high power AC outlets .

Things Take Time.

They've been working on those models for several years. If some other company starts cooperating with Renault to incorporate the Chameleon technology in their cars now, then the first cars to actually use it might hit the road in two to four years. Maybe less if they can modify a design they're already working on instead of starting from scratch.