100% Bonus Depreciation Is Back: Your Commercial Solar Tax Strategy in 2026
If you own a business in Oregon or Washington, you likely view a solar installation as a way to cut overhead costs and lock in predictable energy rates. You aren’t wrong, but in 2026, the tax picture is better than most business owners realize.
For savvy business owners, solar isn’t just an energy upgrade; it is a powerful financial lever.
At Sunbridge Solar we have spent over 15 years helping Pacific Northwest businesses navigate solar finance. Here is the headline for 2026, and it is genuinely good news for businesses: the commercial Investment Tax Credit survived the 2025 tax changes. The residential credit (Section 25D) did not (it ended on December 31, 2025) but commercial projects under Section 48E remain eligible, subject to timing rules. To qualify, construction must begin by July 4, 2026, or the system must be placed in service by December 31, 2027. Everything below applies to commercial and business-owned systems, not to homes.
There is also good news on depreciation: 100% bonus depreciation has been restored on a permanent basis, so the phase-down that used to force a year-end decision no longer applies. Here is your plain-English guide to maximizing your commercial solar tax benefits this year.
What is Solar MACRS?
MACRS stands for Modified Accelerated Cost Recovery System.
In simple terms, it is the method the IRS uses to determine how fast you can write off the value of a business asset. While most commercial buildings are depreciated over a long 39-year timeline, qualifying solar energy equipment is classified as 5-year property.
This means you don’t have to wait decades to recover your investment. You can write off the depreciable basis of your solar system entirely over a five-year schedule. This accelerates your tax savings, keeping more cash in your business when you need it most, now.
Bonus Depreciation: 100%, and Permanent
For several years bonus depreciation was phasing down under the Tax Cuts and Jobs Act, falling toward zero and giving businesses a reason to rush a decision before year end. That phase-down no longer applies.
The One Big Beautiful Bill Act restored 100% bonus depreciation on a permanent basis for qualifying property acquired after January 19, 2025. The IRS has since issued guidance confirming the permanent 100 percent additional first year depreciation deduction.
What this means for you: the entire depreciable basis of a qualifying commercial solar system can be written off in year one, and there is no depreciation deadline pushing you to sign by December. The timing pressure that does exist sits with the Investment Tax Credit under Section 48E, not with depreciation.
What the First Year Actually Looks Like
Here is the arithmetic on a hypothetical $100,000 commercial project, assuming the 30% Investment Tax Credit applies to it.
| Financial Metric | Amount |
| System Cost | $100,000 |
| 30% Tax Credit (ITC) | $30,000 |
| Depreciable Basis* | $85,000 |
| Bonus Depreciation Claimed (100%) | $85,000 |
| Standard MACRS (Year 1) | $0. The basis is already fully written off |
| Total Year 1 Tax Deduction | $85,000 |
| Value of Deduction (@ 21% Tax Rate) | ~$17,850 |
*The Depreciable Basis is calculated as Cost minus half the ITC value ($100k – $15k = $85k).
The Bottom Line: between a $30,000 credit and roughly $17,850 of first-year depreciation value, a business in this example recovers close to half the project cost in year one. Your own figures depend on entity type, tax rate and state treatment, so run them with your CPA rather than with ours.
The “Solar Tax Stack”: How It Works in Practice
The magic happens when you stack federal incentives with our specific regional benefits in Oregon and Washington. Let’s walk through the full calculation for a 2026 installation.
Step 1: The Federal Investment Tax Credit (ITC)
First, you claim the 30% ITC. This is a dollar-for-dollar reduction of your tax liability.
- Credit: $30,000
Step 2: Calculate the Depreciable Basis
The IRS requires you to reduce the basis of the asset by half of the ITC value before depreciating it.
- Depreciable Basis: $100,000 – ($30,000 / 2) = $85,000
Step 3: Apply Depreciation
With 100% bonus depreciation, the full $85,000 basis can be written off immediately.
- Year 1 Bonus Write-off: $85,000
Because the basis is fully depreciated in year one, nothing remains to carry into the standard 5-year MACRS schedule. If you elect a lower bonus rate instead, the remaining balance follows the standard table below.
Total Year 1 Deduction: $85,000
The Result
Between the 30% tax credit ($30,000) and the cash value of your first-year depreciation (~$17,850 at a 21% rate), you have effectively recovered close to 48% of your project cost in the first year.
(Note: This is a simplified example. Always consult your CPA to understand your specific solar business tax advantages.)
The Full 5-Year MACRS Depreciation Schedule
Solar equipment is treated as five-year property, but the schedule actually runs across six tax years. The half-year convention assumes the asset was placed in service mid-year, so year one gets half a year’s depreciation and the remainder rolls into a sixth year. These are the standard percentages from IRS Publication 946, Table A-1:
| Tax year | Depreciation rate | Deduction on an $85,000 basis | Tax value at a 21% rate |
| Year 1 | 20.00% | $17,000 | $3,570 |
| Year 2 | 32.00% | $27,200 | $5,712 |
| Year 3 | 19.20% | $16,320 | $3,427 |
| Year 4 | 11.52% | $9,792 | $2,056 |
| Year 5 | 11.52% | $9,792 | $2,056 |
| Year 6 | 5.76% | $4,896 | $1,028 |
| Total | 100% | $85,000 | $17,850 |
Where the $85,000 basis comes from. On a $100,000 commercial project claiming the 30% Investment Tax Credit, the IRS requires you to reduce the depreciable basis by half the credit value, so $100,000 less $15,000 leaves $85,000 to depreciate. That is the step most online calculators get wrong, and it is why a “30% credit plus full depreciation” pitch overstates the benefit.
The right-hand column assumes a 21% federal corporate rate purely to show the method. Your actual rate depends on entity type and bracket, and state treatment differs again, Oregon and Washington do not handle depreciation identically. Run your own numbers with your accountant rather than ours.
This applies to commercial and business-owned systems. The residential clean energy credit (Section 25D) ended for systems placed in service after December 31, 2025 and homeowners cannot depreciate a home solar system.
Frequently Asked Questions (FAQ)
We know commercial solar finance can be complex. Here are the most common questions our commercial clients ask.
What if I don’t have enough tax liability to use the credit this year?
This is a common scenario. The good news is that the Investment Tax Credit (ITC) can generally be carried back 3 years or carried forward for up to 22 years. If you can’t use the full $30,000 credit in 2026, you simply bank it for future tax years. Depreciation losses can also typically be carried forward as a Net Operating Loss (NOL).
Does this apply to battery backup systems?
Yes. Under the Inflation Reduction Act, standalone energy storage systems (batteries) with a capacity of at least 5 kWh are eligible for the 30% ITC and MACRS depreciation, even if they are not charged 100% by solar. This is huge for businesses looking for energy resilience.
What happens if I sell my building?
If you sell the property within 5 years of placing the solar system in service, you may be subject to “recapture” rules. The IRS will “claw back” a portion of the ITC (20% for each full year early that you sell). However, standard depreciation recapture may also apply. Many business owners choose to include the solar system value in the building sale price to offset this.
Can I depreciate a new roof if I install solar on it?
Generally, no. The roof itself is considered a structural component of the building and is depreciated over 39 years. However, the solar equipment on top of the roof remains 5-year MACRS property. There are some gray areas regarding “improvements” necessary for the solar installation, so this is a critical question for your CPA.
State-Specific Incentives: The Cherry on Top
The Pacific Northwest offers unique advantages that further sweeten the deal.
For Oregon Businesses
In addition to federal write-offs, MACRS solar depreciation in Oregon is often complemented by cash incentives from the Energy Trust of Oregon.
- Trust Matters: As an Energy Trust of Oregon Trade Ally, Sunbridge Solar helps you qualify for these competitive cash incentives, which can directly offset your upfront costs.
- Top-Rated Quality: Our installations are verified by the Energy Trust, ensuring your system performs exactly as promised.
For Washington Businesses
Washington offers one of the most powerful incentives in the country: the Solar Sales Tax Exemption.
- 100% Exemption: For solar energy systems up to 100kW (which covers most small-to-medium businesses), you pay 0% sales tax on the equipment and installation.
- Immediate Savings: This instantly saves you roughly 10% on the project cost right out of the gate, maximizing your ROI before you even file your federal taxes.
Checklist: How to File for Your Solar Tax Benefits
While Sunbridge Solar handles the permitting and installation, your tax professional will handle the filing. Here is a checklist to hand to your CPA to ensure you don’t miss a beat.
- Proof of “Placed in Service”: Ensure you have documentation (PTO letter from utility) showing the system was placed in service within the Section 48E window that applies to your project.
- IRS Form 3468 (Investment Credit): This is used to claim the 30% Federal ITC.
- IRS Form 4562 (Depreciation and Amortization): This is used to report the MACRS and Bonus Depreciation deductions.
- State Forms (WA only): Ensure your invoice clearly separates qualifying solar equipment to validate the sales tax exemption (we handle this on our end!).
Why Partner with Sunbridge Solar?
Navigating commercial solar tax benefits in the PNW requires a partner who understands both the technology and the policy.
- 15+ Years of Experience: We are locally owned and have been serving Oregon and Washington businesses for over a decade.
- Turnkey Solutions: We handle the permitting, the utility paperwork, and the incentive applications so you can focus on running your business.
- Unmatched Warranty: We stand behind our work with a 10-year craftsmanship warranty and install products with 25-year manufacturer warranties.
Stop Overpaying on Taxes. Start Generating Power.
Bonus depreciation is no longer on a countdown, so we are not going to invent a deadline for you. The real timing question is the Section 48E Investment Tax Credit: construction must have begun by July 4, 2026, or the system must be placed in service by December 31, 2027. Whether a given project qualifies depends on its specific timing, and that is a question for your CPA.
Don’t leave money on the table.Call us at 360-313-7190 to schedule your free, no-obligation consultation. Let’s build a custom energy solution that works for your bottom line.
