Don said:
... in addition to the panels and their mounting you would need inverters to get from the DC output of the panels to 120 or 240 volts AC to run the charger.
Would you really need the inverter? If:
a) The first thing that the onboard charger does is rectify the incoming current; and
b) The onboard charger quite happily accepts any voltage in the 120-240VAC range; and
c) The onboard charger dynamically adapts its current consumption based on the J1772 pilot signal...
Then you could, for example, put 5 or 6, 30 or 35V panels in series for somewhere between 150 and 210VDC and directly connect that (through safety relays, etc., like a normal AC-input EVSE) to your J1772 input, and monitor the voltage and current and modulate the J1772 signal to do MPPT.
If those conditions are true and you dispensed with the inverter, then:
1) No cost for the inverter
2) No losses through the inverter
3) (Possibly) less loss through the rectifier in the onboard charger (as compared to 120 VAC) due to higher average voltage (depending on how rectification is done in onboard charger)
4) No compromises on charging current -- dynamically adjust to extract as much power as possible for any given sky condition.
Edited to add:
Hmmm, DC GFCIs to protect humans don't seem to be a thing, or at least not a cheap thing. So (safety second; quality is job 3; etc..) it might be best to use an inverter just so you can have reliable shut-off with leakage current. Wouldn't necessarily need a sine wave output, though, and a square wave could be much more efficient.