@nepobon - I appreciate you just received two conflicting responses..... @Critter-3 is correct and I've tested it on a dummy tax return to prove it. The EV credit gets consumed first as it is 'use it or lose it' in the current tax year. The solar credit that can't be used is carried over to the next year.
More specifically, look at Line 18 of Form 1040 (and let's assume the line numbers will be the same in 2022). Line 18 is your tax liability and the credits can be used to reduce this number to no less than zero. In other words, Line 22 can't be less than zero.
First, the EV credit is used to reduce Line 18. If line 18 is less than the EV credit, you lose the rest of the EV credit as it can't be carried over to the next year.
Then, the Solar credit is used to further reduce Line 18 (less the EV credit) to no less than zero. Whatever can not be used is carried over to the next year and the next year and the next year, etc. until it is consumed.
if you have children, this is where @Critter-3 's comment about 'it could get interesting' comes into play. Unlike 2021, up to $600 per child of the child tax credit also is used to reduce Line 18 and that credit is also 'use it or lose it' in the current year. So with children, whatever is on Line 18 is going to be reduced by up to $600 per child in any event in 2022. it is very complicated
