Solar car charger?

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R P

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Just wondering if there is such a thing. Is it possible to set up solar panels (large ones) on your roof, independent of the grid, with no batteries, and just charge your car. Is there a charge controller/inverter that you can buy that can produce either 120V that can go directly into your car (through the EVSE)? I know you can tie your solar system into the grid, and use it that way with no batteries. But that is not what I am asking.

We have a solar system at our cabin (works very well), but it has batteries, with a separate charge controller and inverter. No grid there, and a lot of power gets wasted when we are not there.
 
Yes it could be done. Based on my current Kyocera panels you would need five panels (3'x5') to generate 1.4 kw. It would take 66 sq ft of panels. This would allow you to run the trickle charger that comes with the car. My panels are 325 watts per panel at 48 volts . Connecting them to a 48 volt pure singe wave 2kw or greater inverter would allow you to charge the car (slowly). Yes you can run with out batteries but when the voltage drops either to clouds or setting sun the inverter will show a low voltage alarm and or shut off. By roof I assume your referring to the house and not the Kona. You could also run 12 or 24 volt panels with the appropriate inverter. You would probably need a neutral to ground bonded inverter (more expensive) to avoid the evse having a ground fault error. It would also need to be an off grid or hybrid inverter and not a grid tie inverter. Of cource this is the simple explanation. A qualified designer would need to properly lay out the appropriate electrical design and controls.
 
That is definitely possible. The capability of exporting to the grid is only so that you're not wasting the energy and to recuperate some of the cost to pay for the system.

As long as you can produce 120V you should be able to hook up your standard EVSE. However (!!!) I'm not sure how stable that is. In theory the EVSE should switch off of it cannot deal with the supplied power.
 
Fastnf said:
Yes it could be done. Based on my current Kyocera panels you would need five panels (3'x5') to generate 1.4 kw. It would take 66 sq ft of panels. This would allow you to run the trickle charger that comes with the car. My panels are 325 watts per panel at 48 volts . Connecting them to a 48 volt pure singe wave 2kw or greater inverter would allow you to charge the car (slowly). Yes you can run with out batteries but when the voltage drops either to clouds or setting sun the inverter will show a low voltage alarm and or shut off. By roof I assume your referring to the house and not the Kona. You could also run 12 or 24 volt panels with the appropriate inverter. You would probably need a neutral to ground bonded inverter (more expensive) to avoid the evse having a ground fault error. It would also need to be an off grid or hybrid inverter and not a grid tie inverter. Of cource this is the simple explanation. A qualified designer would need to properly lay out the appropriate electrical design and controls.
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Yeah, but can you connect the charger directly to an inverter without any batteries in between? I have a 1000W PV system at our cabin, MPPT charger (60 amps), with 24V battery system (4 6Vs in series) and a 3000W (1500 continuous) 110V inverter that is connected to the batteries.

I have noticed that panels have become really cheap here lately. I can get 305W (72 cell) panels for $125 each or 10 for a $1000. And that's CAD, not USD. Apparently these are sourced from Vietnam and a lot cheaper than the Chinese ones (I think there is duty on those). So it got me thinking, that it might be worthwhile to put some PVs on my roof at home, and charge my car during the day. But I don't want to go to the expense of tying into the grid (would need to be certified installation and inspected).
 
I believe him and I answered the question. Yes, of course it can be done. The question is about the equipment (properly grounded for the EVSE to be happy) and enough (and stable) power. If those problems are solved there is no reason why not. In the end your car is just a battery on wheels. It is a little bit pickier than a few old car batteries in the back, though. And most likely more expensive to fix if anything goes wrong.
 
Esprit1st said:
I believe him and I answered the question. Yes, of course it can be done. The question is about the equipment (properly grounded for the EVSE to be happy) and enough (and stable) power. If those problems are solved there is no reason why not. In the end your car is just a battery on wheels. It is a little bit pickier than a few old car batteries in the back, though. And most likely more expensive to fix if anything goes wrong.
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Yeah, maybe I shouldn't have asked if it can be done. I am sure it can, but is it feasible? I know my current (and cheap) solar charger can't operate without a battery system. The instructions are pretty clear, that you need to first hook it up to batteries before connecting to the PVs and in reverse when disconnecting. And I searched for some hybrid charger inverters, but for the power needed to charge a car and harness 1000W PV power or more, it would cost more than the PV panels. It might be cheaper to get a couple small batteries (enough for 24V in series) and high capacity charger (like I have at the cabin), and a high current inverter.

But was hoping that maybe someone knows of a solution that would give me that again, at not too great a cost. And no, I want nothing to do with pro installers, as their time and products they would use would again not make it feasible. I have seen some real nightmare stories at our lake, where some cabins had some very expensive systems installed by pros, only to have them fail (fry their batteries usually), and then pay a fortune again to have them fixed. Mine is DIY, cheap, and works great. So I am looking for something that I can install myself.
 
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R P said:
Yeah, maybe I shouldn't have asked if it can be done. I am sure it can, but is it feasible? I know my current (and cheap) solar charger can't operate without a battery system. The instructions are pretty clear, that you need to first hook it up to batteries before connecting to the PVs and in reverse when disconnecting. And I searched for some hybrid charger inverters, but for the power needed to charge a car and harness 1000W PV power or more, it would cost more than the PV panels. It might be cheaper to get a couple small batteries (enough for 24V in series) and high capacity charger (like I have at the cabin), and a high current inverter.

But was hoping that maybe someone knows of a solution that would give me that again, at not too great a cost. And no, I want nothing to do with pro installers, as their time and products they would use would again not make it feasible. I have seen some real nightmare stories at our lake, where some cabins had some very expensive systems installed by pros, only to have them fail (fry their batteries usually), and then pay a fortune again to have them fixed. Mine is DIY, cheap, and works great. So I am looking for something that I can install myself.
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I think it really depends on the inverter and the electronic controls in it. Basically the battery is like a suspension on a car, it absorbs the shock, and gives a smooth ride. In this case of the inverter the batteries absorbs the excess power and feed it back at a constant rate which give the inverter a stable input and output. Yes the cheapest way would be to throw in a couple of 100 amp hour batteries and not worry about it. Other wise you going to be looking at the specs of your panels, and inverter and weather patterns to design a system that works. Cheaper to just add the batteries
 
A hybrid is a grid tie inverter that can operate on batteries when the grid is down. Most grid tie inverters go down when the grid goes down. Most off grid inverters can't be grid tied. Another way to look at is that hybrid inverter can operate either in a grid tie mode or an off grid mode. The Tesla power wall uses a hybrid inverter.

I don't know why they are calling those inverter you listed hybrid, because they are not. they are off grid. Hybrid inverters should be ul listed 1741
 
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Fastnf said:
A hybrid is a grid tie inverter that can operate on batteries when the grid is down. Most grid tie inverters go down when the grid goes down. Most off grid inverters can't be grid tied. Another way to look at is that hybrid inverter can operate either in a grid tie mode or an off grid mode. The Tesla power wall uses a hybrid inverter.

I don't know why they are calling those inverter you listed hybrid, because they are not. they are off grid. Hybrid inverters should be ul listed 1741
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Yeah, am only interested in off grid and no battery if there is such a thing. AliExpress has thousands of these things, but not sure which if any can be a charger/inverter that can be used without a battery.

Life is so much simpler with my cabin solar system. Maybe I need one of these to use up some of that excess power there...
https://ranger.polaris.com/en-ca/ranger-ev/
 
From what I have seen it's much more expensive control wise to run an inverter with out a battery. If you want more details just search "running off grid solar panels without batteries." Most say it can be done but don't bother.
 
Fastnf said:
From what I have seen it's much more expensive control wise to run an inverter with out a battery. If you want more details just search "running off grid solar panels without batteries." Most say it can be done but don't bother.
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Yeah, it was an idea when I saw these cheap PV panels, but I guess probably not a good one... At this time, my EV charging is still all free, so really can't justify it for that. But was also thinking of my house where our monthly electricity charges are not trivial, esp in the summer with A/C.

I did just find this one. In the description after the specs, says it can operate with or without batteries.
https://www.aliexpress.com/item/330...earchweb0_0,searchweb201602_,searchweb201603_
Total system (incl 3kW PVs) would still cost about $2000,... not cheap.
 
I did just find this one. In the description after the specs, says it can operate with or without batteries.
https://www.aliexpress.com/item/330...earchweb0_0,searchweb201602_,searchweb201603_
Total system (incl 3kW PVs) would still cost about $2000,... not cheap.[/QUOTE]

Based on the information provided this is a hybrid inverter. It says it can operate without batteries but I would be cautious. Most hybrid only operate without batteries when they are grid tied and the grid is up. Also it has only a 1 star review. It possible that it might work but more likely its just bad marketing.
 
Fastnf said:
I did just find this one. In the description after the specs, says it can operate with or without batteries.
https://www.aliexpress.com/item/330...earchweb0_0,searchweb201602_,searchweb201603_
Total system (incl 3kW PVs) would still cost about $2000,... not cheap.
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Based on the information provided this is a hybrid inverter. It says it can operate without batteries but I would be cautious. Most hybrid only operate without batteries when they are grid tied and the grid is up. Also it has only a 1 star review. It possible that it might work but more likely its just bad marketing.[/QUOTE]
Thanks for your review. I just wanted to see what is out there, and feasible. Your recommendation of a battery based system still seems the best option. At this time, though, I am not ready to tackle this at home. However, those cheap PVs are tempting. But they are polys, so not actually the best.
 
papab said:
The 'best' way would be direct with a solar charge controller.
If you google: 'solar charge controller for tesla car', quite a bit of interesting stuff comes up.
https://www.mobile-solarpower.com/1212121.html
Be careful
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Some very expensive solutions out there..., might as well just continue charging from the grid.

This is still the cheapest that I have found. Can charge directly to my car through an EVSE from solar panels, and no aux storage batteries required. Would work for Tesla or any EV with their EVSE. There are several sellers of this product on on AE, with very good reviews.
https://www.aliexpress.com/item/330...earchweb0_0,searchweb201602_,searchweb201603_
But even this is not feasible for me. Maybe if I installed a whole house system tied to the grid, with the ability to also charge directly to my car from the solar panels, it might be worthwhile. Would have to do the math, of course, before knowing for sure. It is the recent new low price of PV panels that got me interested in these types of solutions.
 
I'd start by talking to the folks at myenergi.

Their zappi EV charger dynamically adjusts the power output to match solar generation.
 
gooki said:
I'd start by talking to the folks at myenergi.

Their zappi EV charger dynamically adjusts the power output to match solar generation.
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That's just the charging station (EVSE). Still need the above setup I posted (or something like it) for the solar charger/inverter. And that Zappi will not work here (North America) if it requires the supply voltage (from your inverter) to be 230V and 50 Hz. Looks like it is designed for EU countries and others that use 230V.
 
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