As you have probably read, this is an area that the IRS has
not yet ruled on.
If you spent $3,000 in 2016 on solar panels, but your tax liability was only
$2,000, then you could take only the $2,000 for 2016, and carry over the $1,000
to 2017.
But that is all the instructions
for form 5695 (2016) say.
I see an
industry report that the IRS has extended the credit to 2021, which raises
the hope that carryovers may run to 2021, but I cannot find an IRC reference
yet.
See the IRS Q&A for
more background.
If the industry report is true that the credit has been extended to 2021, then
the carryovers are likely extended as well.
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