Hello,
This is an interesting concept. Let me quote the IRC and an IRS Notice. It appears that a full-timer who uses a class A, fifth wheel or TT as principal residence does qualify.
There may be an argument that the first bold limitation is descriptive and the second bold sentence permits the credit for an RV. You should share this with your CPA who will make the decision.
Crespro
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I.R.C. ยง 25D(d)(2) Qualified Solar Electric Property Expenditure โ The term โqualified solar electric property expenditureโ means an expenditure for property which uses solar energy to generate electricity for use in a dwelling unit located in the United States and used as a residence by the taxpayer.
Q&A on Tax Credits for Sections 25C and 25D
Notice 2013-70
SECTION 1. PURPOSE
This notice provides guidance with respect to the credits for nonbusiness energy property under ยง 25C of the Internal Revenue Code (Code) and residential energy efficient property under ยง 25D of the Code. This notice incorporates the changes made to ยง 25C by section 710 of the Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010, Pub. L. No. 111-312, 124 Stat. 3296 (2010) (the 2010 Act) and to ยง 25C and ยง 25D by sections 104 and 401 of the American Taxpayer Relief Act of 2012, Pub. L. No. 112-240, 126 Stat. 2313 (2013) (the 2012 Act).
SECTION 3. QUESTIONS AND ANSWERS RELATED TO BOTH ยง 25C (NONBUSINESS ENERGY PROPERTY) AND ยง 25D (RESIDENTIAL ENERGY EFFICIENT PROPERTY)
Q-6: Are the credits available for improvements made to a second home (for example, a vacation home or an investment property)?
A-6: Improvements made to a second home are not eligible for the credit under ยง 25C.
Section 25C(c) and (d) require qualified energy efficiency improvements and residential energy property to be installed in or on a dwelling unit owned and used by the taxpayer as the
taxpayerโs principal residence (within the meaning of ยง 121).With respect to the credit under ยง 25D, fuel cell property credits are not available for second homes. Section 25D(d)(3) requires fuel cell property to be installed on or in connection with a dwelling unit that is used as the taxpayerโs principal residence (within the meaning of ยง 121).
However, a taxpayer may claim a ยง 25D credit for other qualifying properties described in ยง 25D that are not fuel cell properties (solar electric property, solar water heating property, small wind energy property, and geothermal heat pump property) installed in or on a dwelling unit used as a second home or a vacation home by the taxpayer. But a taxpayer may not claim the ยง 25D credit for expenditures for improvements made to an investment property, such as rental property, that is not also used as a residence by the taxpayer.
(2) Dwelling unit. For purposes of this paragraph (e), the term dwelling unit has the same meaning as in section 280A(f)(1), but does not include appurtenant structures or other property.
Sec. 280A(f)Definitions and special rules
(1)Dwelling unit defined For purposes of this sectionโ
(A)In general The term โdwelling unitโ includes a house, apartment, condominium,
mobile home, boat, or similar property, and all structures or other property appurtenant to such dwelling unit.
Crespro 2021 Grand Design 310GK-R, 2020 F250LB, 7.3L, 4.30, Reese 27K