Owner-occupied businesses can combine the 30% federal solar tax credit with accelerated depreciation (MACRS) to recover a large share of a commercial solar system’s cost through the tax code alone. The credit reduces your taxes dollar-for-dollar. Depreciation reduces your taxable income on top of it. Stacked together, they are the reason well-designed commercial systems often reach payback in 3 to 5 years.
Both benefits are tied to placing the system in service, and the 30% credit is scheduled to end December 31, 2027, so the window to lock in the full stack is closing.
See your credit and net cost matched to your electric bill with the SolarTech Commercial Calculator.
What is bonus depreciation for commercial solar?
Depreciation lets a business deduct the cost of a capital asset, such as a solar system, against its taxable income over time. For solar, the IRS allows an accelerated schedule called MACRS (Modified Accelerated Cost Recovery System), which recovers most of the cost over a short window rather than decades.
“Bonus depreciation” is an additional first-year provision that has historically let businesses deduct an extra large share of the cost immediately. The exact bonus percentage changes with federal law, so the current-year figure should be confirmed with your CPA. The principle holds either way: solar depreciation front-loads a substantial deduction.
How does depreciation stack with the 30% tax credit?
They are two separate benefits that apply to the same system:
| Benefit | What it does | How it is applied |
|---|---|---|
| 30% Investment Tax Credit (ITC) | Cuts federal tax owed | Dollar-for-dollar credit |
| MACRS and bonus depreciation | Cuts taxable income | Deduction against income |
A common structure: you claim the 30% credit, and you depreciate the system’s cost basis, reduced by half the credit, per IRS rules. The combined effect is that a large portion of the system is effectively paid for through the tax code, before you count a single dollar of electricity savings.
What does that do to payback?
Utility savings alone typically put a commercial system around a 4 to 5 year simple payback. Layering in depreciation pulls the after-tax payback shorter, frequently into the 3 to 5 year range for owner-occupied businesses with the tax appetite to use the deductions.
| Benefit layer | Effect on economics |
|---|---|
| Electricity savings only | Baseline payback, roughly 4 to 5 years |
| Plus the 30% tax credit | Cuts net cost by about 30% up front |
| Plus MACRS and bonus depreciation | Recovers much of the remaining basis via deductions |
| Plus avoided rate escalation of 3% to 5% per year | Grows savings every year the system runs |
Estimates only, not tax advice. Your benefit depends on your tax situation.
Who can actually use the depreciation benefit?
Depreciation only helps a business that has taxable income to offset. That makes the ideal candidate:
- Owner-occupied, where the business owns both the building and the solar system
- Profitable enough to use the deductions, since unused amounts may carry forward. Ask your CPA.
- In California with high commercial rates, where utility savings are also large
Owner-occupancy is the key. If you own the building and the system, you are positioned to claim both the credit and depreciation cleanly. If the building is leased, the structure determines who gets what, which is worth mapping out early with your accountant.
Why the 2027 deadline changes the math
The 30% credit is the larger and more time-sensitive of the two benefits, and it is scheduled to drop after December 31, 2027. Since the credit is earned at Permission to Operate (PTO), and commercial projects take 4 to 6 months, the practical deadline to sign is early 2027. Wait too long and you can lose the credit portion of the stack entirely, which is what turns a 3 to 5 year payback into something far less attractive.