Portable Photovoltaic CHAdeMO or J1772

[TimeHorse]

I just read through this thread about hacking the CHAdeMO and wonder if anyone has consider as the new handle may be much cheaper and as we understand the communication protocol better would it be practical to get a roll of Photovoltaic and just plug it in via DC-DC conversion on CHAdeMO or with an inverter to J1772? I can't charge at work and don't expect they're gonna let me any time soon so I'm thinking the only way I'm going to get a supplimental, idle charge is to set up my own Photovoltaic station. I know the old CHAdeMO connector Ingineer is selling is almost $3000 but I guess the new handles are cheaper, though I've not seen a price quote. Obviously these need to come down in price to be practical but from an electrical point of view, which would make more sense, DC-DC CHAdeMO or Inverter-AC J1772 given that the Wattage we're talking about is maybe 100W.

 

[EVDRIVER]

I just read through this thread about hacking the CHAdeMO and wonder if anyone has consider as the new handle may be much cheaper and as we understand the communication protocol better would it be practical to get a roll of Photovoltaic and just plug it in via DC-DC conversion on CHAdeMO or with an inverter to J1772? I can't charge at work and don't expect they're gonna let me any time soon so I'm thinking the only way I'm going to get a supplimental, idle charge is to set up my own Photovoltaic station. I know the old CHAdeMO connector Ingineer is selling is almost $3000 but I guess the new handles are cheaper, though I've not seen a price quote. Obviously these need to come down in price to be practical but from an electrical point of view, which would make more sense, DC-DC CHAdeMO or Inverter-AC J1772 given that the Wattage we're talking about is maybe 100W.

May need a battery buffer on that system for peak loads. EVSE upgrade just lowered the price of that cable to $2K at the moment not $3K which is the cost.

 

[adric22]

would it be practical to get a roll of Photovoltaic and just plug it in via DC-DC conversion on CHAdeMO or with an inverter to J1772?

Wouldn't it be cool if we could keep a roll-up solar panel in the hatch. When at work, just unroll it over the entire car and plug it in! Not only would it keep your car cool in the Summer, but you would gain a few miles of range. I bet the cost would be astronomical, though.

 

[Nubo]

I just read through this thread about hacking the CHAdeMO and wonder if anyone has consider as the new handle may be much cheaper and as we understand the communication protocol better would it be practical to get a roll of Photovoltaic and just plug it in via DC-DC conversion on CHAdeMO or with an inverter to J1772? I can't charge at work and don't expect they're gonna let me any time soon so I'm thinking the only way I'm going to get a supplimental, idle charge is to set up my own Photovoltaic station. I know the old CHAdeMO connector Ingineer is selling is almost $3000 but I guess the new handles are cheaper, though I've not seen a price quote. Obviously these need to come down in price to be practical but from an electrical point of view, which would make more sense, DC-DC CHAdeMO or Inverter-AC J1772 given that the Wattage we're talking about is maybe 100W.

Not sure you're considering how big of a solar array it would take to put a substantial charge into your car. 8 hours of charging at 100w will net you about 4 miles range and that's before you figure in losses and the fact that solar is only at peak for a few hours.

 

[coqui]

Why not have every horizontal surface of the car covered in solar cells? Sure, it isn't going to get you more than a few miles of range. But with the car sitting in the sunny tree-less office parking lot all day, and an employer that has no intention of providing charging stations, seems a good idea to me.

 

[garygid]

I doubt that 100W is enough to run the LEAF's charging system, either J1772 or QC, properly.

The minimum current from a 120v EVSE might be about 6 amps (720 watts) or so.

 

[smkettner]

Bypass the charging system with ~800 solar cells in series

 

[davewill]

I doubt that 100W is enough to run the LEAF's charging system, either J1772 or QC, properly.

The minimum current from a 120v EVSE might be about 6 amps (720 watts) or so.

That's the lowest that the J1772 pilot signal can be set to (see http://code.google.com/p/open-evse/wiki/J1772Basics" onclick="window.open(this.href);return false, but I seem to recall Phil doubting that the LEAF could actually go that low.

 

[JeremyW]

Bypass the charging system with ~800 solar cells in series

And what happens when one of the "in series" cells gets shaded?

100 watts is a joke amount of solar power for this application. There exists no solar charge controller ether, and don't be thinking you can "get away" without one. Such a low power high voltage device would be expensive and totally not worth it. No, you are not looking at "a few miles" of range, you are looking at a few feet.

I've said it before, if you want to play around with solar on the car, use safety and common sense and stick with the 12 volt side of things. MPPT charge controllers for lead acid are somewhat cheep and plentiful. You can get a Morningstar sun saver 15 Amp MPPT controller for $250 that will work great for your average grid tie panel (200w).

Jeremy

 

[planet4ever]

I thought, with the CHAdeMO protocol, that the car dictates a (variable) voltage to the charger. How are you going to handle that with your "roll of Photovoltaic"?

Ray

 

[lpickup]

Why not have every horizontal surface of the car covered in solar cells?

Probably because it would jack the price of the car up so much for such a small benefit. Just not cost effective.

 

[EVDRIVER]

Here's an idea. How about a trailer with solar panels to charge the car. Why not add some fan generators as well and tie them to the pack directly. Or perhaps a solar kite that can be flown behind the car?

 

[adric22]

Why not have every horizontal surface of the car covered in solar cells?

Probably because it would jack the price of the car up so much for such a small benefit. Just not cost effective.

I believe the guy on the Nissan videos (Mark Perry, I think?) actually said this exactly, that it was essentially a cost/benefit decision and decided the cost was simply too great for the benefit. Not that it wouldn't work, though.

 

[TimeHorse]

Yes, I know 100W is peanuts, but that's to start. I'd envision it like this, start with 1 panel, then 2, up to enough to cover an entire parking space next to mine. As in, drive a LEAF, park like a Hummer and take 2 spaces, one for the car, the other for the solar array. Wouldn't cost anything but an extra space to the employer and I know they have spaces to spare. And the idea is to grow it over time so there's no great upfront cost beyond the initial engineering. Just plug and play more panels when done.

 

[mkjayakumar]

How many panels would I need if I need to get some L1 level charging?

 

[lpickup]

How many panels would I need if I need to get some L1 level charging?

Well, if you lived in ideal conditions and could orient this perfectly towards the sun to get peak output, you'd need 26 of these flexible solar panels at $230 each, or around $6 grand. Each one is 12 sq feet, so you're talking about 312 square feet in total. I don't know how many square feet a standard parking spot is, but let's assume 120 square feet. So you'd need your own spot plus one on either side. Oh, they also weigh about 9 pounds each, so you'll have to lug around an extra 234 pounds of solar panels.

My guess is that after you go to all this trouble though you're probably going to wind up with less than 50% of the peak output. So all this effort and on a sunny day maybe you'll get an extra 15 miles of range while you're at work for 8 hours...

Yes, as you guys are saying, you might be able to get it to work. But do you really think it's worth it?

 

[essaunders]

I've pondered the idea of buying an old box truck, putting panels on the roof, batteries in the back and then an inverter to drive an EVSE. Assuming your employer would tolerate the permanent parking, this might be actually feasible.

rough costs?

~$2000 for a 17' box truck
$800x6 for 200W panels (no idea if this is right) = $4800
~$1000 for an inverter (can solar MPPtracker and EVSE supply be combined?), another $500 for (open) EVSE
batteries $2000 maybe?

$8500 or so. I'm sure my ROM could be beat (but I probably also left out a bunch of stuff too!)

 

[TimeHorse]

Oh, they also weigh about 9 pounds each, so you'll have to lug around an extra 234 pounds of solar panels.

Very good points, but the nice thing is I only need it in one place as most other places I go are EV friendly as I like to give business to EV friendly places (which in this area is spelled M-A-R-Y-L-A-N-D, stupid General Assembly in Richmond!) so I could just store it at work; maybe bring the stuff here, assemble it after hours, put it on casters and roll it our each day when I come in. Mind you, now I need storage and a way to keep it from blowing around but I suppose I could just leave it in the parking lot overnight. At least where I work is secure from poaching and vandals.

 

[JeremyW]

Yes, as you guys are saying, you might be able to get it to work. But do you really think it's worth it?

Agreed. I love solar, but do acknowledge that this is a variable resource. You are very likely not going to see anything close to nameplate capacity with those panels.

There's a bit more then 300 watts of overhead (~78% efficient) associated with the on board charger at level 1 power levels. If you can set up 3.8 kW of power the onboard charger will have 90% efficiency. That's after your inverter loss to get your panel DC to AC. Even if your inverter was 90% efficient, the best you could hope for overall is in the low 80's.

How many L2 chargers could you install for $8,500? I would think that most places that would tolerate the box truck would let you pay for the EVSE install or otherwise work out an agreement.

That being said, there is a market for a solar charge controller that is CHAdeMO compliant (galvanically isolated output and follows the protocol).

The coolant pumps (there are 2) run all the time while charging, pump one runs at 39% duty-cycle and pump two runs at 44%. The speed does not change regardless of charging power, which is why there is significant fixed overhead while charging. Why this was chosen by Nissan is a mystery.

By going DC into the pack, the question of overhead is now external to the car. This means a lot for lower power levels where power electronics can scale down in price and complexity.

I still think solar on the car would be fun. Say 60 watts (like the Prius roof available) in bright sun, that's 60 watts that you aren't drawing from the DC/DC when you're cruising around at noon with the AC blasting- making up for the blower fan draw. The point is you can "add" a bit of range without messing with high voltage through the notion of an accessory watt saved is a traction watt earned.

Jeremy

 

[Herm]

L1 charging is 1500W, so all that you would need is about 6-7 of those 230w panels.. probably a workable solution if you go camping with your Leaf and just need about 30 miles of range per day. Its an interesting solution for campers since it would provide power for your needs as well.