Quick answer
U.S. federal depreciation rules for eligible business or income-producing property; solar classification, basis, method, convention and bonus eligibility require current project-specific assessment.
Answer: MACRS is the U.S. federal system for recovering eligible business or income-producing property costs through depreciation deductions. For solar projects, classification, basis, recovery method, convention and bonus eligibility require current project-specific tax review. A deduction reduces taxable income; it is not the same as a dollar-for-dollar tax credit. Historic solar schedules and bonus percentages should not be applied automatically to a current installation.
Current rules need a dated assessment
As checked on September 30, 2026, IRS Publication 946 (2025) reports that P.L. 119-21 reinstated 100% special depreciation for certain qualifying property acquired and placed in service after January 19, 2025, subject to eligibility and elections. A universal 2025–2027 phase-down table is therefore inappropriate.
The same publication notes removal of solar or wind property beginning construction after December 31, 2024 from one specified five-year classification, while separately describing five-year treatment for qualifying facilities, investments and storage under the newer provisions. These provisions must be assessed together for the actual asset. Do not infer that every solar project qualifies for five years or that all solar property lost five-year treatment.
Ask the customer’s tax adviser to confirm acquisition, construction-start and placed-in-service facts, applicable classification and elections. A quote date alone cannot select the tax treatment.
Separate the cost, basis and deduction
The installation invoice is not automatically the depreciable basis. Ownership, eligible business use, cost allocation, credits and other adjustments matter. Land and different asset components need their own treatment. A private homeowner’s personal-use system should not be modeled as depreciable business property simply because it produces electricity.
IRS Form 3468 instructions describe investment-credit provisions and associated requirements. Obtain the approved credit and basis adjustments for the actual project; do not assume a 30% credit or a universal half-credit adjustment applies to every present-day quote. Depreciation and credit eligibility are related tax questions, not interchangeable labels.
An explicitly conditional schedule example
Suppose the accountant has already confirmed an $85,000 depreciable basis, five-year GDS property, the 200% declining-balance method and half-year convention, and no bonus deduction or other adjustment for this illustration. These assumptions are not a classification of a current solar installation.
| Tax year | Illustrative table percentage | Deduction |
|---|---|---|
| 1 | 20.00% | $17,000.00 |
| 2 | 32.00% | $27,200.00 |
| 3 | 19.20% | $16,320.00 |
| 4 | 11.52% | $9,792.00 |
| 5 | 11.52% | $9,792.00 |
| 6 | 5.76% | $4,896.00 |
| Total | 100.00% | $85,000.00 |
The six tax-year entries arise from the declared half-year convention; they do not establish six years of equipment life. A different convention or bonus treatment changes the schedule.
At a separately assumed constant 21% tax rate, full immediate usability of all scheduled deductions would imply $85,000 × 0.21 = $17,850 of undiscounted tax reduction across the schedule. The deduction is not $85,000 of cash savings. Actual utilization, tax rates and timing can differ. The present value also differs from that undiscounted total.
Keep bonus treatment separate
A special first-year allowance changes when basis is deducted. Any remaining basis requires the applicable treatment, rather than repeating the full regular schedule on the original basis. Elections and limitations can alter the result. Do not use a generic low bonus percentage as sales urgency without a current tax determination.
A one-year write-off is not a universal cash refund and does not itself establish the best project economics. Entity structure, deduction limits, taxable income and state conformity need separate assessment. Avoid assuming allocations to partners or shareholders follow a simple ownership percentage in every case.
Records for the financial handoff
Retain the asset and cost breakdown, ownership and use, dated acquisition and construction evidence, placed-in-service record, classification, method, convention, elections, approved basis adjustments and adviser’s schedule. Track federal and state assumptions separately. Update a proposal if the actual facts or applicable rules differ.
The financial model should distinguish depreciation deductions, modeled tax effects, credits, debt and operating cash flows. Sales teams can explain those components while leaving eligibility and filing treatment to the customer’s qualified tax adviser. Confirm which schedules and inputs a software demonstration supports; do not promise automatic current-law compliance.
Sale, disposal or a change in use may have tax consequences. Depreciation recapture and credit recapture are distinct questions, and the end of a nominal recovery period does not universally remove every tax consequence. Review a proposed transaction with the tax adviser using the actual history.
Common questions
Does every commercial solar system qualify for five-year depreciation?
Do not assume it. Current classification and the project’s facts require verification.
Is depreciation the same as a tax credit?
No. Depreciation is a deduction; the resulting tax effect depends on the taxpayer and timing.
Can an old bonus phase-down table be reused for 2026?
Not automatically. Current legislation, acquisition and service dates, eligibility and elections matter.
Does a large deduction guarantee immediate cash savings?
No. Actual usability and tax treatment must be determined for the taxpayer.
Related Glossary Terms
About the Contributors
Co-Founder · SurgePV
Akash Hirpara is identified by SurgePV as a company co-founder. His SurgePV author page lists only role information that can be tied to the public profile below; education, certifications, project totals, financial results, speaking engagements, and media appearances are not asserted without retained evidence.
Editorial contributor · SurgePV
Rainer Neumann is credited as an editorial contributor on SurgePV content. This profile does not assert engineering credentials, project totals, software-testing experience, education, speaking engagements, or media citations because independent verification evidence is not retained in the publication record.
