Commercial Solar Tax Credit After July 4, 2026: The December 31, 2027 Deadline—and Why Battery Storage Still Qualifies

Thinking about solar for your business, school, farm, or parking lot? The federal tax credit is still available—but the clock is now running.

For most new commercial solar projects, the federal clean electricity investment credit now depends on one date: the system must be placed in service by December 31, 2027.

That is roughly fourteen months from today. For a commercial project that needs design, utility review, permits, equipment, and construction, that is not a long time.

Call Option One Solar at (855) 502-6363 to find out whether your project can realistically meet the deadline.

The Rules Changed in 2025. The Deadline Is Real.

The One Big Beautiful Bill Act, signed July 4, 2025, shortened the life of the federal credit for commercial solar under Section 48E.

Solar projects that did not begin construction by July 4, 2026 generally must be placed in service by December 31, 2027 to qualify. Projects that properly began construction on or before July 4, 2026 may have more time, subject to the IRS continuity rules.

In August 2025, the IRS issued Notice 2025-42, which tightened how a project proves it "began construction." For most solar projects, the old 5% spending safe harbor is no longer available—physical work of a significant nature is required. Solar facilities of 1.5 megawatts (AC) or less retain a limited exception.

If you were told you could "lock in" the credit by buying equipment late in 2026, verify that advice with your tax professional. For most new projects today, the practical deadline is being operating by the end of 2027.

Battery Storage Is Treated Differently

The accelerated deadline applies to wind and solar. It does not apply to energy storage.

Under current law, standalone and paired battery energy storage systems can still qualify for the Section 48E credit for projects that begin construction through 2033, with a phase-down after that (The Tax Adviser, Feb. 2026).

For many California businesses, storage is also where the value is moving. Under the current utility rules, battery storage can reduce demand charges, shift solar production into higher-cost evening hours, and keep critical loads running during outages.

If solar cannot be completed in time, storage may still make financial sense on its own—and solar may still make sense without the credit. The numbers should decide, not the deadline alone.

Learn more about commercial battery storage.

Foreign-Entity Rules Now Affect Equipment Choices

The 2025 law also added "prohibited foreign entity" restrictions. Depending on when construction begins, credits may be denied if too much of a project's equipment or components come from restricted sources.

This is a sourcing and documentation question, not just a price question. The lowest-cost panel, inverter, or battery may not be the lowest-cost project if it puts the credit at risk.

We review equipment origin and documentation with you and your tax advisor before you commit.

What It Takes to Finish by December 31, 2027

A commercial project does not start on the day the crew arrives. Before construction, the work typically includes:

• Site evaluation, electrical review, and 12 months of utility usage.

• System design and engineering, including structural review for roofs or carports.

• Utility interconnection application and review.

• Building and electrical permits.

• Equipment procurement and delivery.

• Construction, inspection, and utility permission to operate.

Utility interconnection and permitting are often the longest steps, and they are not in your control or ours. That is why the time to start is now, not next summer.

"Placed in service" is a tax term with its own requirements. Your tax professional should confirm how it applies to your project.

Here is a useful detail: a system set to non-export is legally operational, and it can count as placed in service for the credit. Our non-export systems do not require PTO (permission to operate) from the utility, so that step does not have to hold up your deadline. Your tax professional should confirm how this applies to your project.

Do Not Let the Deadline Push You Into a Bad Program

Deadlines attract salespeople. Urgency is not a reason to accept a poor design, an unlicensed contractor, or an agreement you do not understand.

We feel strongly about this: a commercial solar project should be judged on its long-term economics—not on how quickly someone can get a signature.

We do not sell traditional escalating solar leases or PPAs. We favor ownership and transparent long-term economics. With an ownership structure, the business that hosts the system generally claims the credit and keeps the long-term value. Under a traditional third-party agreement, the owner keeps the tax benefits, and your business may face escalators and buyout costs.

Bring us any commercial lease or PPA proposal. We will help you compare it with an ownership option over the same time period.

Verify the Contractor Before You Sign

For commercial solar, verify an active California C-10 electrical or C-46 solar contractor license appropriate to the work through the CSLB License Check. Option One Solar holds both, under CSLB License #985340.

Also confirm bonding, workers' compensation, and general liability coverage, and ask how many commercial projects the company has completed and who will perform the work.

Projects of 1 megawatt (AC) or more generally must meet prevailing wage and apprenticeship requirements to receive the full credit amount. Ask how your contractor will document compliance.

Why Businesses Choose Option One Solar

We understand electrical systems, solar, and battery storage—and how they need to work together.

Our roots began with J&L Electric in 1970. Our founder, Jerry Thomas, served as an electrical supervisor on NASA's Apollo space program and as Chief Electrical Inspector for Pasadena, Los Angeles, and Santa Monica.

Today, our experience includes more than 5,000 solar installations, three generations of family involvement, and both C-10 electrical and C-46 solar contractor licenses. We design, fabricate, and erect commercial solar carports entirely in-house, and we provide full-service commercial O&M after the project is complete.

As a GSA-approved provider, we also serve government and Department of Defense customers with solar and battery resilience systems.

That depth of experience matters when a deadline leaves no room for a redesign.

Is solar still worth it without the credit?

Yes, absolutely. The credit is a nice bonus, but it was never the whole story.

The real value is replacing expensive utility power with power your business makes itself. Once the system has paid for itself, the savings do not stop. They keep going for years after payback.

We have seen payback in as little as 3 years, with self-generated power costing as little as one-tenth of the utility rate.

Let us put your electric bill to the test and show you what solar can do for your bottom line. Call (855) 502-6363 or contact us to get started.

Payback and savings vary by project. Any incentives included in payback calculations are identified in your proposal. Utility fees and demand charges may remain.

Other Questions About the 2026 Commercial Solar Tax Credit

Is the residential solar tax credit still available?

No. The residential clean energy credit (Section 25D) for homeowners who purchase a system ended for systems placed in service after December 31, 2025. See our incentives page for what remains available to homeowners.

Does a solar carport qualify?

A commercial carport that supports solar generation equipment is generally part of the solar project and subject to the same deadline. Confirm the treatment of the structure with your tax professional.

Can we add batteries later?

Often, yes. Storage added to an existing system may qualify on its own timeline. We evaluate electrical capacity, utility rules, and operating goals before recommending an addition.

Let's Find Out If Your Project Can Make the Deadline

The credit is still available. The window is not.

With electrical contracting roots dating to 1970, more than 5,000 solar installations, in-house carport fabrication, and both C-10 and C-46 licenses, Option One Solar has the experience to plan, build, and support your project.

Call (855) 502-6363 or contact us to schedule a commercial project review.

We will explain what we find, what we recommend, and what the proposed work will cost.

Related reading

Commercial solar · Commercial battery storage · Solar carports · Pros and cons of commercial solar · Solar panels for commercial use · Financing

Sources

• 26 U.S.C. § 48E (as amended by P.L. 119-21): https://uscode.house.gov/us/usc/119-124/t26/s48E/

• IRS Notice 2025-42, Beginning of Construction: https://www.irs.gov/pub/irs-drop/n-25-42.pdf

• The Tax Adviser, "Navigating safe-harbor rules for solar and wind Sec. 48E facilities" (Feb. 2026): https://www.thetaxadviser.com/issues/2026/feb/navigating-safe-harbor-rules-for-solar-and-wind-sec-48e-facilities/

• Nixon Peabody, "Changes to beginning construction rules" (Aug. 2025): https://www.nixonpeabody.com/insights/alerts/2025/08/28/changes-to-beginning-construction-rules-for-clean-electricity-tax-credits

• CSLB License Check: https://www.cslb.ca.gov/OnlineServices/CheckLicenseII/checklicense.aspx

Option One Solar does not provide tax, legal, accounting, or financial advice. Federal tax credits, bonus depreciation, MACRS depreciation, direct pay, transferability, domestic content bonuses, energy community bonuses, low-income community bonuses, and other incentives depend on each customer's specific facts and circumstances. Customers should consult their CPA, tax advisor, and legal counsel before relying on any tax incentive, depreciation benefit, or projected tax savings.