Solar is the one depreciation question where almost every article you will find is now wrong. For years the answer was clean: a solar array on a rental was 5-year MACRS property, you wrote it off fast, and that was the whole story. Then the rules changed for systems that began construction after 2024, and the top search results did not update. If you put panels on a rental recently, the recovery period you owe may be very different from the one a blog post promises.
The cost of a system is real money, often $15,000 to $40,000 on a single-family rental, so the recovery period is not a footnote. Five years versus 27.5 years is the difference between a deduction you feel now and one you collect a little at a time for nearly three decades. Here is what actually governs it today, the basis step that gets skipped, and why this particular page comes with a stronger CPA recommendation than the rest of the series.
What changed, and the date that decides it
The 2025 Publication 946 “What's New” section spells it out: section 70509 of P.L. 119-21 removed solar and wind energy property from the definition of 5-year property under section 168(e)(3)(B)(vi), and that removal applies to property beginning construction after December 31, 2024. The phrase that controls your answer is beginning construction, not the date the panels turned on. A system that began construction in 2024 and was placed in service in 2025 still rides the old 5-year class. A system that broke ground in 2025 does not, at least not on the old grounds.
So the first thing to pin down is the construction-start date, in writing, from your installer's contract and permit records. That one date sorts your system into one of three buckets, and the buckets carry very different schedules.
The three buckets for a solar array
- Began construction before 2025: still 5-year MACRS property. The fast write-off survives for these systems, on the same class life solar always had.
- Began construction after 2024 and qualifies under the clean energy path: the IRS page on cost recovery for qualified clean energy facilities, property, and technology describes a separate route under sections 45Y and 48E, placed in service after 2024, that may still reach a 5-year MACRS life (the IRA provision 13703 treatment). Those sections carry their own qualification rules and their own post-2025 legislative phase-outs, so you cannot assume you land here.
- Qualifies under neither: the array is treated as a capitalized improvement to the building. For a residential rental that means 27.5-year straight-line depreciation, the same recovery period the structure itself uses. This is the slow bucket, and it is where a lot of recent systems will land.
If your system falls into that third bucket, it behaves like any other capital improvement: its own in-service date, its own schedule, added to line 18 alongside the building. The mechanics there are the same ones in the rental property depreciation guide, including the mid-month convention on a 27.5-year asset.
The basis cut almost everyone forgets
Whatever bucket you are in, if you claimed an investment tax credit on the system, you do not depreciate the full cost. Basis has to be reduced by 50% of the credit claimed before depreciation starts. Say a system costs $30,000 and you claim a $9,000 credit. You reduce basis by half of that, $4,500, and depreciate $25,500, not $30,000. Run the schedule on the full $30,000 and you have overstated the deduction every single year, which is the kind of error that compounds quietly until a sale forces a reckoning.
Depreciable basis = system cost − (50% × investment tax credit claimed).
Keep the credit form, the installer invoice, and the basis math together in one place. The number you depreciate is not the number on the invoice, and the only way to defend it later is to show the arithmetic.
Improvement, not repair
A new solar array is unambiguously an improvement, never a current-year repair. It adds a new system to the property and extends its capacity, so it is capitalized and recovered over time rather than deducted in full this year. That puts it on the wrong side of the line for an immediate write-off and on the right side of the schedule. If you are unsure where any given roof, panel, or wiring job lands, the test is the same one laid out in repairs vs improvements on a rental. Replacing one cracked panel might be a repair; installing the system is not.
A related trap: the Residential Clean Energy Credit, section 25D, is the one homeowners talk about, and it never applied to a property you do not live in. 2025 legislation also terminated it for expenditures after 2025. So when a homeowner-facing article tells you to grab that credit, none of it transfers to your rental. The credits that touch a rental are different, with different rules, which is exactly why the numbers here are not a do-it-yourself project.
Where this leaves your year
Once the recovery period is settled, the year's depreciation drops onto Schedule E line 18 along with the building and every other improvement schedule you are running, the same line walked through in the Schedule E line-by-line guide. The hard part is never the division. It is knowing which bucket your system is in, carrying the reduced basis, and still having the construction-start date and the credit math findable in year eight. If you want to see what the 27.5-year fallback schedule looks like in dollars, the depreciation calculator runs the mid-month convention.
Holding those inputs is the part that falls apart in a spreadsheet, and it is the part rents.ai was built to hold: it flags capital expenses into their own depreciation schedules and keeps line 18 current as the year moves, though it will not decide which bucket your solar system belongs in. That judgment, on a rule this new and this contested, is a CPA's call, and the only job for any tool here is to keep the records that make their call faster, not to make the call.
The primary sources, if you want to read them rather than another paraphrase, are Publication 946 (how to depreciate property, where the “What's New” note on solar lives) and the IRS page on cost recovery for qualified clean energy facilities, property, and technology.
More than any other page in this series: get a CPA on this one. The rules changed in 2025, the qualification paths carry their own phase-outs, and the basis reduction is easy to miss. These figures are estimates to organize your year for your CPA, not tax advice. Bring them your construction-start date, your installer invoice, and your credit form, and let them rule on the recovery period.