@HB88 wrote:
Thanks for the feedback.
I guess I'm a little perplexed why a few CPA I have spoken with and one with strong conviction stated it is not possible to make a second claim.
In 26 USC §25D also I don't see anything specifically stating it is allowed either. Not sure why the IRS would leave this question unanswered as surely this can't be an uncommon issue with people expanding their systems.
Congress wrote the law, the issue is whether the IRS has, or should, write a regulation to cover this situation that is not described in the law.
I did find a private letter ruling that covers the battery issue.
https://www.irs.gov/pub/irs-wd/201809003.pdf
https://www.ballardspahr.com/alertspublications/legalalerts/2018-03-07-irs-rules-solar-energy-storag...
First note that "Like all IRS private-letter rulings, the 2018 ruling is binding only on the taxpayer who received it and may not be used or cited as a precedent. It may provide guidance, however, as to the thinking of the IRS on the issues presented, and may indicate the likelihood that a proposed letter ruling involving similar facts will be approved."
Second, note that with respect at least to a battery system to store solar power and release it to your home at night or on cloudy days, the battery and it's connecting components are only "qualified solar property" if the battery is exclusively connected to the solar panels and can't be charged by the public utility grid. So some whole house backup batteries may not be "qualified solar property."
The private letter ruling does not discuss new solar panel capacity but I see no reason to doubt my prior statement.
