Upcoming call to Aerovironment about DC quick chargers

[walterbays]

SDGE has volunteered to the CPUC to install and run chargers in these undeveloped areas. Obviously, if they get approval, you WILL GET CHARGERS. With control of the cost of electricity and the demand fees internally, I think we'll quickly have a monopoly that nobody else could ever compete with.

I don't necessarily think that SDG&E's aim here is to establish for themselves an eFuel monopoly on the order of Standard Oil. Demand charges have a very valid purpose, to flatten the demand curve to the benefit of investors and ratepayers alike. It's just an unhappy coincidence that high demand charges seem to be keeping DC quick chargers out of California, to the detriment of the EV market. The consequence is loss of an order of magnitude greater flattening of the demand curve by a large EV population.

It's unfortunate that the PUC deliberately chose not to exempt eFuel from demand charges. But given that decision, only the utilities could operate viable DC charging networks. I see SDG&E's proposal more as "stepping into the breach". I'd rather have a monopoly eFuel purveyor than no eFuel purveyor. And all PUC would have to do to break the monopoly would be to exempt eFuel from demand charges, and the utilities could have plenty of competition. And anyway, even if SDG&E did happen to become the 21st century's Standard Oil, remember what happened next to Standard Oil?

 

[Aeolus]

I think it's a horrible idea to let California utilities get into the charging business for reasons too numerous to list.

Instead it's a much better idea to find some legislative solutions that would:

1.) Allow EV charging stations to sell electricity by the KWH without going through the requirement to become a mini-utility.

2.) Exempt EV charging stations from demand fees if more than 20% of the service users are generating alternate peak power or if the charging station is paired with a facility generating energy through a PV system.

3.) Guarantee that public EV charging stations receive the most favored electrical rate available for the time period.

 

[garygid]

In CA, #1 has already been done by the CPUC, I believe.

#2 is difficult with a "public" station where you do not know who the customers are/were.

#3 is another area (PV Generation) that SDG&E is trying to "discourage" with adverse rates. Yes, demand charges triggered by ONE high-usage 15-minute interval during the month (even on a cloudy day when total demand is down, probably due to less A/C usage), with no consideration for even massive Peak-Time Generation ... is just irresponsible over-charging, in my opinion.

It seems that SDG&E does not want to "share" and move fairly into what will become the future. Where else can you put massive fixed assets in place, get paid to maintain them, get all other expenses paid (no incentive to be thrifty), AND get guaranteed a 10% return each year on every building, pole, transformer, manhole cover, and wire?

Quite possibly, that will help "break the back" this tottering world economy. Remember them after the Grid fails, and you are killing each other for food and water!

Right now, Kaiser Hospital/Medical (at 405 and Sand Canyon) is busy installing 88,000 square feet of PV over their parking lot. That is the future struggling to arrive, and the CPUC should actively encourage it!

 

[TonyWilliams]

It's unfortunate that the PUC deliberately chose not to exempt eFuel from demand charges. But given that decision, only the utilities could operate viable DC charging networks. I see SDG&E's proposal more as "stepping into the breach". I'd rather have a monopoly eFuel purveyor than no eFuel purveyor. And all PUC would have to do to break the monopoly would be to exempt eFuel from demand charges, and the utilities could have plenty of competition. And anyway, even if SDG&E did happen to become the 21st century's Standard Oil, remember what happened next to Standard Oil?

I did make my views known in person to the CPUC on the very first day, at the first time they were available to comment on SDGE's petition to get into the EV charger biz.

My recommendation was that SDGE should be allowed NOW to install and operate the EV chargers, and be given a period of time to make their money, but that a sunset clause be issued for them to divest themselves of yet another monopoly.

Otherwise, who would compete with the $1.8 billion monopoly with lopsided rules (demand fees for everybody else) ?

 

[EricH]

In CA, #1 has already been done by the CPUC, I believe.

#2 is difficult with a "public" station where you do not know who the customers are/were.

#3 is another area (PV Generation) that SDG&E is trying to "discourage" with adverse rates. Yes, demand charges triggered by ONE high-usage 15-minute interval during the month (even on a cloudy day when total demand is down, probably due to less A/C usage), with no consideration for even massive Peak-Time Generation ... is just irresponsible over-charging, in my opinion.

It seems that SDG&E does not want to "share" and move fairly into what will become the future. Where else can you put massive fixed assets in place, get paid to maintain them, get all other expenses paid (no incentive to be thrifty), AND get guaranteed a 10% return each year on every building, pole, transformer, manhole cover, and wire?

Quite possibly, that will help "break the back" this tottering world economy. Remember them after the Grid fails, and you are killing each other for food and water!

Right now, Kaiser Hospital/Medical (at 405 and Sand Canyon) is busy installing 88,000 square feet of PV over their parking lot. That is the future struggling to arrive, and the CPUC should actively encourage it!

Gary - you are correct on #1; the CPUC has specifically 'passed' on regulating charge-station owners, rate-wise.

 

[hill]

You have to wonder ... Mitsubishi put up a PV array on top of their Chademo. Could that be specifically so SCE wouldn't kill Mitsu with high electricity charges? Is there someone on mynissanleaf that has an "in" with a Mitsu contact that could possibly fill in the blanks? That info could be VERY helpfull.

.

 

[DaveEV]

You have to wonder ... Mitsubishi put up a PV array on top of their Chademo. Could that be specifically so SCE wouldn't kill Mitsu with high electricity charges? Is there someone on mynissanleaf that has an "in" with a Mitsu contact that could possibly fill in the blanks? That info could be VERY helpfull.

The SCE rate charges are confusing as hell to read as usual, but it appears that there is a $12.15 / kW distribution demand charge.

Summer time energy demand charges are $17.05 / kW - ON TOP - so one 50kW QC charger will cost you $600+ / mo non-summer, and another $850+ in the summer ($1350 / mo for one QC). Add on another $0.05-0.06 / kWh for energy.

http://www.sce.com/NR/sc3/tm2/pdf/ce30-12.pdf" onclick="window.open(this.href);return false;

Let's say you want to get the cost of a 20 kWh quick charge charge (80% charge) to $5 / charge or less in the summer. The energy is going to cost $1.20 at $0.06 / kWh, so you have to get the demand charges down to $3.80. Demand charges are $1350 / mo, so you need to do 355 quick charges a month to hit $5/charge. 30 days a month so that's 12 charges a day - that's a busy QC station!

If you're on TOU energy rates - forget it on Option A - you're stuck paying $0.36 / kWh instead of the $17/kW demand charge. If you go with Option B it's probably similar.

Option R with a PV setup might be the way to go as long as your system generates enough on-peak electricity - You get retail credit at $0.36 / kWh, no summer demand charge and a reduced demand charge. A 40 kW PV array in So Cal would generate enough on-peak electricity on average to basically let you provide 12 QCs/day on demand charges of $5.81 / kW. Of course, a 40 kW PV array is going to cost you about $200k!

 

[Ingineer]

My questions, of course, are price / availability. Also, a big one, can we get a 48kW unit (480v*100a) cut down to 19.2kW (240v*80a or 208v*92a).

Limiting a CHAdeMO charger to a certain amount of power is relatively easy, and could be done with a simple CAN interface board in-between the car and the QC. The QC tells the car it's max power, so all the intercept board would need to do is alter this advertisement, then the car will only ask for amperage up to the original limit.

It should also be little problem to modify a 3-phase unit to accept single phase, as long as you are ok with keeping the power limited.

-Phil

 

[TonyWilliams]

My questions, of course, are price / availability. Also, a big one, can we get a 48kW unit (480v*100a) cut down to 19.2kW (240v*80a or 208v*92a).

Limiting a CHAdeMO charger to a certain amount of power is relatively easy, and could be done with a simple CAN interface board in-between the car and the QC. The QC tells the car it's max power, so all the intercept board would need to do is alter this advertisement, then the car will only ask for amperage up to the original limit.

It should also be little problem to modify a 3-phase unit to accept single phase, as long as you are ok with keeping the power limited.

-Phil

I would LOVE to run 240v single phase at 80amps. That would be my first choice, particularly if it's easy to switch back to 480v*100a/3phase in the future, should CPUC rulings change (or we add some type of battery power). I'm going to guess that all the electronics are typically 100v-240v powered. I personally have no expertise in this area.

An interface board seems more problematic, but I like where you're going with this. We could build our own casting for the ChaDeMo connector, and inside would be the electronics. Or would it be simpler and smarter to put the electronic control "intercepts" in the box? Ok, I'll just answer that myself, and say yes, put the stuff in the box.

Do you have a firm enough grasp of the ChaDeMo language to build a circuit to do this?

 

[TomT]

But to me this just seems self-defeating. The whole idea of QC is, well, quick charging. If you limit it to a fraction of its capability, increasing charging times accordingly, it loses much of its attraction and usefulness that would have been the main reason for drawing people to it in the first place...

Limiting a CHAdeMO charger to a certain amount of power is relatively easy, and could be done with a simple CAN interface board in-between the car and the QC. The QC tells the car it's max power, so all the intercept board would need to do is alter this advertisement, then the car will only ask for amperage up to the original limit. It should also be little problem to modify a 3-phase unit to accept single phase, as long as you are ok with keeping the power limited.

 

[ENIAC]

Initially I suspect DC quick chargers will be used very infrequently. Therefore, it seems like it be far less expensive to use a bank of deep cycle batteries to drive the DC quick charger and use standard, far less expensive, 240v service to recharge the deep cycle batteries.

Also, I wonder if this is a Bloom box opportunity.

 

[TonyWilliams]

But to me this just seems self-defeating. The whole idea of QC is, well, quick charging. If you limit it to a fraction of its capability, increasing charging times accordingly, it loses much of its attraction and usefulness that would have been the main reason for drawing people to it in the first place...

A tall tree with the top cut off is still a tall tree; just less so.

A 20kW ChaDeMo is 6 times faster than the 3.3kW charger in the car for the "meat" of the battery (below 80%). Above 80%, there's not going to be much difference between a 20kW or a 48kW DC charger, as they will both have their charge rate ramped down as the battery approaches 100%.

In other words, a full charge will be faster than 20/48 as fast. Simply put, if it takes 50 minutes to fully charge with 48kW rate (for 83% of 21kWh of usable energy), it might take 90-100 minutes with the 20kW unit. Obviously, we don't know till we actually measure it.

That "meat" of the battery, from 17% (battery warning) to 80% can be charged in 25 minutes, according to Nissan at 48kW max rate. 63% of the battery divided by 25 minutes is 2.5% per minute of charging in the "meat", or about 2 miles per minute below 80% battery capacity at 48kW rate.

The 20kW charger will be almost 1 mile per minute below 80%. Both units are likely to be close to the 25 minutes from 80% to 100% charge.

If you don't find that as a benefit over not having a charger at all, obviously that's your choice.

 

[TonyWilliams]

Initially I suspect DC quick chargers will be used very infrequently. Therefore, it seems like it be far less expensive to use a bank of deep cycle batteries to drive the DC quick charger and use standard, far less expensive, 240v service to recharge the deep cycle batteries.

Also, I wonder if this is a Bloom box opportunity.

No, it's FAR less expensive to limit the DC charger than to BUY and MAINTAIN batteries and chargers and electronics to monitor and manage the batteries. Not to mention their replacements over time.

What's a "Bloom box" ?

 

[Aeolus]

Somewhere I picked up the idea that charging stations in California were not allowed to charge by the KWH, and were thus limited to billing customers by time units, regardless of how much electricity was used during the period. This of course, presents obstacles for charging if Time of use rates come into play or when there are different charging rates for different vehicles.

Of if they did, they would have to go through a huge rigamarole of becoming some sort of independent utility in order to resell electricity.

This would be a function of the utility's monopoly status under state law and/or exclusive franchise agreements with local governments.

Not sure if that was accurate information or not.

Can anyone confirm this or disabuse me of this idea, for sure?

 

[TonyWilliams]

Somewhere I picked up the idea that charging stations in California were not allowed to charge by the KWH, and were thus limited to billing customers by time units.....

Can anyone confirm this or disabuse me of this idea, for sure?

I never envisioned charging by kWh, but instead by time (which is the premium commodity). What rate the car charges at is moot from the charger company's perspective, since the actual electricity is mostly cheap. The time charge might start from occupying the charging stall, since leaving a car in a premium revenue spot for hours without charging would be grossly inefficient, as would be using DC charging for topping off the charge to 100%. Perhaps a 3-5 minute window before and after the charge event would be exempt.

A full charge, from zero to hero, in a LEAF will still only be a few dollars of electricity. For several years, it's likely that any DC charger would be lucky to get used every day. If there was a $1 per minute charge cost, and 30 minutes per day average for the first year or two, that would create $900 per month in gross revenue per charger. Electricity cost would be about $200-$300 (obviously, there are HUGE variations possible in this number), but even on that low usage, each unit might still eek out a profit, depending on how many are deployed to handle the overhead.

I would guess that at $1 / min rate, most charges would be very short and infrequent. Some type of package / membership / high user plan might be significantly cheaper per minute for those folks who are going to be doing monthly charges of longer duration.

 

[abasile]

Above 80%, there's not going to be much difference between a 20kW or a 48kW DC charger, as they will both have their charge rate ramped down as the battery approaches 100%.

Above 80%, there would be zero difference between the two. By the time the SOC reaches 80%, the charge rate has already tapered below 20 kW. I've observed this behavior numerous times in continuous regenerative braking down the mountain we live on.

Assuming 21 kWh usable capacity and 25 minutes to QC from 17% to 80%, the average, standard CHAdeMO charge rate is only about 32 kW.

If my interpretation of this DC fast charge plot is correct, then indeed, that 25 minutes for 17%-80% would roughly double to 50 minutes, given QC limited to 20 kW. Even if one needs to charge from below 17% to higher than 80%, this shouldn't take too much more than an hour. Yes, faster would be better, but an hour really wouldn't be bad at all. And of course at 20 kW, there'd be the added benefit of less stress on the battery pack.

 

[TonyWilliams]

Yes, faster would be better, but an hour really wouldn't be bad at all. And of course at 20 kW, there'd be the added benefit of less stress on the battery pack.

The economy of scale for the projected usage for the first year or three is HUGE.

The monthly cost for that single 30 minute per day average usage for 48kW in San Diego costs:

Charge Rate          48kW         20kW

Demand Charges      $ 4000        $  0
Electricity         $  300         $ 300
___________________________________
Cost per charge     $  143         $  10

 

[tbleakne]

My questions, of course, are price / availability. Also, a big one, can we get a 48kW unit (480v*100a) cut down to 19.2kW (240v*80a or 208v*92a).

I would like to know whether they are seriously considering offering several models with power capabilities even lower, perhaps as low as 10 KW. It certainly seems reasonable that there would be a substantial market for units at a lower price/power point, especially if sited at good locations where folks could profitably spend time eating, shopping, etc. Since these are engineers, not marketeers, perhaps they would share with you estimates of how the cost would scale with power size ?

Is the threshold for Demand Charges 20 KW for SCE as well as San Diego ?

 

[DaveEV]

Also, I wonder if this is a Bloom box opportunity.

What's a "Bloom box" ?

Bloom box is a natural gas (and other similar gas) fuel cell. It's about 50% efficient in steady state at converting gas to electricity.

Problem is that I doubt it ramps up fast enough to be very useful - I think it takes some time to ramp up to 100% power.

And the Bloom box isn't cheap - you're going to get a much better ROI by running it 24/7, but at that point you're still looking at a DC QC as added cost.

The only time you can run a DC QC without added cost is if you can schedule DC quick charges around your existing peak demand charges so you don't increase your overall demand. To do this, your DC-QC is going to need some real-time communications and some "smart-grid" monitoring hardware/software to manage loads.

Not all that uncommon in the business world where businesses are already dealing with demand charges, I suspect, though.

 

[Phoenix]

Nissan transports their Hasetec QC around town to charge the LEAFs at car shows by using a diesel generator. What about just charging our QCs via a biodiesel generator? Anyone know what the cost of such electricity would be if biodiesel is now about $5 per gallon? We then use utility electricity at below demand charge levels.