I need an under 20KW DC ChaDeMo Quick Charger

[ElectricVehicle]

Nichicon 45 kW with 10kWh (Lithium Ion) energy storage Googled to English

If we had time and couuld work with QC manufacturers we could get some useful design variants:

• A bit of onboard storage - say a 35 kW output unit with 10 usable kWh storage would draw 19 kW from the grid for a 30 minute charge... (allowing for intput vs. output power efficiency)
  
  Quick chargers that measure the demand for the ENTIRE site - not too hard - put some current sensors on the power entrance to the site, and control the charging power to keep the site load under some preset level, say 20 kW. A design like this would have the units operating at say, 17 kW output most of the time, but when the air conditioner for the site cycles on, they might drop to 11 kW for the 15 or 30 minutes it takes for the AC to cool down the site and cycle off again.
  
  Solar input to reduce peak demand (you'd charge a little slower at night or during days with heavy black clouds..)

Combinations of all of the above strategies.

Integrating a load leveling energy storage battery into the QC unit itself makes a lot of sense since the power electronics and control are shared by the battery and the charger, reducing the total costs by tens of thousands over using a separate energy storage (high power charger - battery - high power inverter) with a separate Quick Charge unit.

Reducing and limiting the peak demand would also mean QC units couls be installed on samller utility services and avoid some of the costly upgrades. Reduce power output is good for reducing peak kW demand, but will often mean slightly longer charge times, and cosnequently slight fewer users that can be chaeged from one unit during the day.

 

[TonyWilliams]

If we had time and couuld work with QC manufacturers we could get some useful design variants.... A design like this would have the units operating at say, 17 kW output most of the time, but when the air conditioner for the site cycles on, they might drop to 11 kW for the 15 or 30 minutes it takes for the AC to cool down the site....

It is worthwhile to contact progressive QC companies to see IF something can be tweaked in the existing design to meet the sub-20kW load goal.

Anything beyond that just means research and development, lots of money and time. Not looking at just-over-the-horizon.

I would favor having the electricity supplied through a dedicated SDGE meter. The electricity is just not that expensive, at about $2 - $2.50 per 25kWh use.

Installing the power line from SDGE is still relatively cheap.

 

[surfingslovak]

It is worthwhile to contact progressive QC companies to see IF something can be tweaked in the existing design to meet the sub-20kW load goal.

I, for one, would love to see a 12 kW fast charger. It may be easier to host and it would not hit the battery as hard as a regular 24+ kW QC. In fact, it could be even better than slow charging. Perhaps they could make their future products configurable? Why not let the host or the user limit the maximum output current, like the much less sophisticated Voltec SPX EVSE does?

 

[Herm]

Why not let the host or the user limit the maximum output current, like the much less sophisticated Voltec SPX EVSE does?

A fast DC charger can do current limiting automatically, it has to.. its how lithium batteries are charged. So it will be trivial to do what you ask.. Your example is not really valid because thats not a charger, its just a fancy extension cord with some signaling to the true charger inside the car.

A chademo charger is exactly like the charger inside the Leaf, just much bigger and has the ability to dump a lot of power if the connection gets interrupted un-expectedly (no arcing allowed with 500VDC at 125A).

 

[surfingslovak]

A fast DC charger can do current limiting automatically, it has to.. its how lithium batteries are charged. So it will be trivial to do what you ask.. Your example is not really valid because thats not a charger, its just a fancy extension cord with some signaling to the true charger inside the car.

A chademo charger is exactly like the charger inside the Leaf, just much bigger and has the ability to dump a lot of power if the connection gets interrupted un-expectedly (no arcing allowed with 500VDC at 125A).

Right, thanks for explaining that. I believe that I understand the basics, but I was questioning the use case itself. Why is it relatively easy to influence or control the maximum current delivered with L2 charging but not with L3 charging? Seems rather illogical. When pumping gas, I can either use the latch on the nozzle or control the speed manually. This should be an option on L3 chargers. And likewise, the site or business owner should be able to configure the maximum deliverable power at the time of installation. Either that or they should sell these chargers with different rated output power. Am I missing anything or is it an altogether stupid idea?

 

[ElectricVehicle]

Right, thanks for explaining that. I believe that I understand the basics, the DC charger is an external charger and the EVSE is a mere conduit for power to be delivered to the on-board vehicle charger. What I was questioning was the use case itself, why is it relatively easy to influence or control the maximum current delivered with L2 charging but not with L3 charging? Seems rather illogical. When pumping gas, I can either use the latch on the nozzle or control the speed manually. This should be an option on L3 chargers. And likewise, the site or business owner should be able to configure the maximum deliverable power at the time of installation. Either that or they should sell these chargers with different rated output power. Am I missing anything or is it a stupid idea?

Setting a lower current (power) limit for a fast charger is relatively easy if you are the manufacturer. They'll all have little computers controlling them and respond to commands from the car. So you just add a feature to the software or create a special version the limits the max current / power to the level you desire. So you could take a 50 kW Quick Charger, get a different version of software installed on it from the manufacturer that sets it to 12 kW output max. It would take 13 or 14 kW from the utility. Or set the output limit to 10 kW and it will draw less than 12 kW from the utility.

The Quick Charge has to reduce the charge rate towards the end of charge so they really should be able to do this with a special software version and no hardware changes. The down side is you're still paying $10,000+ for 50 kW worth of power electronics but only using 12 kW. Like buying a 1000 watt power supply for your computer but only using 250 watts at most from it. Mind you many networked level 2 EVSE are selling for $1,500 - $5,000 and public installationo is expensive, so while you don;t want to waste money, in the big picture, paying a few thousand for power capacity in the Quick Charger that you're never going to use isn't so terrible, especially goven the choice of that or no Quick Charger at all for the site!!

That's actually a brilliant idea, since we might be able to work with supliers to get one of their standard quick chargers with an option for power limit by software. NO new hredware or ceritifcation, just a tweak of their code! Way cheaper than any hardware changes at this point.

 

[TonyWilliams]

....choice of that or no Quick Charger at all for the site!!

The obvious point when folks are splitting hairs on the value of that quick charge when you really need it !!!

 

[EVDrive]

+1


We could also have lots of 19KWH chargers each run by an independent local ev non-profit.
Another option would be to regular 50KWH chargers installed at businesses that currently pay a peak demand charge.

Still, even with Only ONE 19.9 kW Charger, that does NOT solve the problem, unless each charging station is a separate "business".

Any other usage (lights on, etc.) or multiple charging stations would result in over 20kW usage peaks.

The real solution is for the PUC to edict that electrical usage for "Vehicle Charging Stations" is NOT subject to "demand" charges, and must have a reasonable rate structure.

In the meantime, it appears that QC will suffer, and be delayed, just as some "forces" would like to have happen.

Because, with economical and well-deployed QC, the EV becomes a REAL competitor to the ICE and OIL usage!

 

[garygid]

Does a non-profit NOT pay the Peak Demand Fee?

If so, the non-profit could lease/rent the property (its use) from the business owner.

One non-profit could own many charging machines at many locations, right?

 

[TonyWilliams]

Does a non-profit NOT pay the Peak Demand Fee?

No. They'd pay, as the charge is for "infrastructure". Something to specifically ask SDGE.

The previous post about using a facility already paying the fee; of course, sounds awesome. How many big businesses are there with that set up? Of that number, how many would agree to potentially add to their current demand fee?

And then ask them to buy the power, accept whatever liability, and in Ecotality's case, pay them half the fees they get, whether they charge a fee, or not.

Let's just say that isn't working out.

 

[garygid]

Who maintains the QC machines?

 

[walterbays]

Does a non-profit NOT pay the Peak Demand Fee?

I think the only special non-profit rate schedule is for group living homes etc. http://www.sdge.com/tm2/pdf/ELEC_ELEC-SCHEDS_E-CARE.pdf

With the current demand charge I agree that a 20 kW ChaDeMo makes much more economic sense than a 60 kW one. But it would not be a "quick" charger. If a 60 kW unit refills a Leaf from 0% to 80% in 30 minutes then a typical usage might be more like 27% to 80% in 20 minutes, which is just about right to have a cup of coffee at the hosting business. When it's done you're right there to unplug and drive away, letting the next driver have his/her turn.

If it instead takes 90 minutes to get that charge you're not going to wait around. The chargers would have to be located somewhere there was something to do nearby. There would need to be perhaps 4 parking spaces reachable by the charger cord so that if someone didn't come back in time his car could be unplugged so the next person could charge. If you had to wait for one car ahead of you, and then wait for your own charge, you'd be scarcely better off than with an L2 charge - IF one were available at a better location with something better to do while you wait.

If the charger had a big battery built in like Randy suggested it would be better. Then it could charge at 40 kW for 20 minutes while drawing 20 kW from the grid, then "rest" for 20 minutes still drawing 20 kW to recharge the battery. (Or 20 minutes plus extra to account for inefficiencies charging and discharging the unit's battery.) I think the chargers being used about half the time during the day is about as much as you'd want to plan for, to avoid excessive wait times. But such a charger should really be designed around the load leveling battery, not cobbled together out of ad hoc pieces. And the manufacturer would be designing to fit a specific artificial market condition created by a strange quirk of California's electricity regulations. CPUC could come to their senses tomorrow, and all the engineering design work would be wasted.

The best hope might be if the charger were hosted by a business that already used a substantial amount of electricity and which had opportunities for load shedding using devices like this, http://www.demandcharge.com/index.htm It might reduce air conditioning slightly when a car started charging, and increase it when the car was finished. Or if the building were already too hot it might slow down the charging rate for a while. But negotiating an agreement with a host for equitable cost sharing in that situation would be a formidable task.

 

[TonyWilliams]

designing to fit a specific artificial market condition created by a strange quirk of California's electricity regulations. CPUC could come to their senses tomorrow, and all the engineering design work would be wasted.

The CPUC is not going to come to their senses tomorrow> (stolen from the PGE thread):

http://docs.cpuc.ca.gov/published/Final_decision/139969.htm#TopOfPage" onclick="window.open(this.href);return false;

Section 5.4 states that rates will be reviewed in 2013 since "The EVSP Coalition stated that the Commission should revisit existing Electric Vehicle rates after it has obtained a sufficient understanding of consumer Electric Vehicle usage and charging by early adopters. Two studies that will yield instructive results are Ecotality's Electric Vehicle Project and Coulomb's ChargePoint America."

 

[EVDrive]

Energy rates in California are not set up to encourage EV deployment and adoption. PG&E only has a good rate if you have solar otherwise you get hammered for exceeding your base allotment.

In general, I like the idea of a 19kwh charger as it should be way cheaper, smaller and easier to deploy than a 50 or 100kwh charger.

designing to fit a specific artificial market condition created by a strange quirk of California's electricity regulations. CPUC could come to their senses tomorrow, and all the engineering design work would be wasted.

The CPUC is not going to come to their senses tomorrow> (stolen from the PGE thread):

http://docs.cpuc.ca.gov/published/Final_decision/139969.htm#TopOfPage" onclick="window.open(this.href);return false;

Section 5.4 states that rates will be reviewed in 2013 since "The EVSP Coalition stated that the Commission should revisit existing Electric Vehicle rates after it has obtained a sufficient understanding of consumer Electric Vehicle usage and charging by early adopters. Two studies that will yield instructive results are Ecotality's Electric Vehicle Project and Coulomb's ChargePoint America."

 

[surfingslovak]

If a 60 kW unit refills a Leaf from 0% to 80% in 30 minutes then a typical usage might be more like 27% to 80% in 20 minutes, which is just about right to have a cup of coffee at the hosting business. When it's done you're right there to unplug and drive away, letting the next driver have his/her turn.

If it instead takes 90 minutes to get that charge you're not going to wait around.

Refilling from 27% to 80% in 90 minutes implies a 9 kW charger even when including some losses. This is not what is being discussed here. What if I wanted to put 6 kWh into the battery and had 20 minutes to spare? The difference between 20 minutes (20 kW charger ) and 10 minutes (40 kW) charger is not so stark. Level 2 charging implies that it's done via an onboard charger, and in the case of the Leaf L2 will be limited to 3.3 kW for some time to come.

 

[TonyWilliams]

The best hope might be if the charger were hosted by a business that already used a substantial amount of electricity and which had opportunities for load shedding using devices like this, http://www.demandcharge.com/index.htm It might reduce air conditioning slightly when a car started charging, and increase it when the car was finished. Or if the building were already too hot it might slow down the charging rate for a while. But negotiating an agreement with a host for equitable cost sharing in that situation would be a formidable task.

And that formidable task would exist for every single charger site you wanted to adopt. In other words, of a QC infrastructure, it ain't gunna happen.

Interesting points on the slower DC quick charge. It would be interesting to get a feel for how many would prefer a full powered charger (25 minutes to 80%) for $Y.00 per charge, or a 90 minute charge at $Y.00 divided by 3 or 4.

I personally would want the 25 minute one, even at the substantial premium. The rest of the time, I can use cheap L2's at 3.3kW.

 

[TonyWilliams]

Refilling from 27% to 80% in 90 minutes implies a 9 kW charger even when including some losses. This is not what is being discussed here. What if I wanted to put 6 kWh into the battery and had 20 minutes to spare? The difference between 20 minutes (20 kW charger ) and 10 minutes (40 kW) charger is not so stark

If 50kW does that in 25 minute, then a 20kW charger should be able to do the same charge in something close to 50/20 of 25 minutes, or 62.5 minutes. 9kW ---> 50/9(25) = 138 minutes.

Maybe there is market to have both chargers for two different fees to the user?

 

[smkettner]

I think your planned setup is inefficient. Why take DC from the batteries, go to AC, then back to DC?

We're on the same page... here's what I said in that same post >>>> "then a gigantic inverter, to then be converted to DC to pump in the car, seems horribly inefficient."

Eliminate the inverter. The Batteries charge at ~48kW for less than 20 minutes, then switch to a lower charge rate. If you use the 20kw from the grid feeding in additionally, you would only need around 15kWh of batteries-- eliminate 85% of the batteries.

What is the input to the DC quick charger? I'm guessing 480 3 phase AC? How do you get the batteries of the charging station to power that without an inverter? .

The 3 phase is converted to DC in the charger. You just feed the DC battery power to the machine direct and bypass the rectified 3 phase power supply.
Good luck with the UL listing.
I assume the charge controls are on the DC side.
That is about 250 lead acid cells in series.

 

[TonyWilliams]

Who maintains the QC machines?

Not sure what you're asking. Whoever owned it would have some kind of service agreement/warranty.

If you get one from Ecotality, I know they maintain it.

 

[TonyWilliams]

Good luck with the UL listing.

Is that required?