After you file

The solar credit can only be used to offset "income taxes", not self employment taxes or other types of taxes or penalties

Look at a copy of your 1040 tax return, Line 44 (I think) is your tax liability that can be offset by the solar credit....is that amount the $2900 ?
♪♫•*¨*•.¸¸♥Lisa♥ ¸¸.•*¨*•♫♪