residential solar thermal credit

[Docblack]

I installed a solar thermal water system in 2019, but was unable to use entire credit.  Will be unable again this year.  How long will that carry forward?  Is there an action I must take to carry it forward to another year?

[MinhT1]

The solar credit can be carried forward for 20 years. You do not have to take any specific action to carry it forward.

[Opus 17 · Accepted solution]

[edited]  You need to include form 5695 on your tax return to report the carryover, calculate that you can't use any of it, and carry it forward again.  There are specific instructions on how to do this on the form, if you were filing by hand.

Go to the Energy Credits section of the Deductions and Credits page.  Start the interview, answer "yes" that you "made improvements or had a carryover", answer all the qualifying questions, and leave the boxes blank for all the improvements (because you did not make them in 2020).  You will eventually get to a question, did you have a carryover from 2019?  Answer yes, and the amount.