I never implied that EVs would be charged by rooftop solar at night. Solar is one part of an overall power supply that would use different power sources at different times of the day. Currently even the most green power supples still use some fossil fuels to supplement baseline power at night. The most carbon intensive source, coal, is being replaced. Natural gas is still a common baseline power source. Longer term the aim is to replace that with a combination of other sources that product less power. Batteries and other ways of short term power storage will hold power produced during the day with solar and release it at night. All of this is in ongoing development and will take decades to fully transition.EVs mostly charge overnight so they aren't being powered by rooftop solar anyhow, I do have solar but now it's only useful here if you use it up during the day, the FIT you get back is hardly anything.
Good if you work from home while your car is charging maybe, but then add aircon, pool, office, everything else running, rainy days, winter etc etc
The most effective way to use solar is for it to be connected to the grid and incorporated into the overal power supply. Electrons are fungible and you don’t need to charge only from your own solar power to take advantage of solar power.
With all of that an EV will still produce less CO2 than any gasoline car on any power mix and the EV will produce less as the power mix becomes cleaner.