Critical Changes to Commercial Solar Tax Credits: What Every Business Needs to Know

Summary of 2025 ITC Changes: Under the "One Big Beautiful Bill" (OBBB), businesses must begin construction by July 4, 2026, to qualify for the full 30% Investment Tax Credit (ITC) safe harbor. Alternatively, projects must be placed in service by December 31, 2027. Recent executive orders have tightened "safe harbor" definitions, making early project development critical to ensuring eligibility. Click Here for more information on the Residential Energy Credit (Section 25D) for homeowners. 

The Big Picture: Commercial Solar Timeline Accelerated 

On July 4, 2025, President Trump signed the “One Big Beautiful Bill” (OBBB) into law, setting in motion a rapid timeline shift for commercial solar tax incentives. Among the bill’s provisions are the accelerated phaseouts of Sections 48E and 45Y, creating a sense of urgency for businesses considering solar energy. 

Major Changes to the Investment Tax Credit (ITC) 

The OBBB begins sunsetting the commercial solar ITC for projects that begin construction after July 4, 2026, removing the previously planned gradual phase-down. 

Key Deadlines: 

• July 4, 2026: Final day to begin construction and still qualify for the full ITC safe harbor. 

• December 31, 2027: Projects that don’t qualify for safe harbor must be completed and placed in service by this date to receive the full credit. 

New Executive Order May Impact Safe Harbor Rules 

On July 7, 2025, President Trump issued an executive order eliminating federal subsidies for what it calls “unreliable green energy sources” such as wind and solar. This directive reinforces the OBBB by ordering the Treasury Department to tighten enforcement and phase out tax credits. 

This executive order could alter how "beginning construction" is defined for safe harbor purposes, potentially making it more difficult to qualify for the traditional 4-year completion window. Harvest Solar is closely monitoring guidance from the Treasury Department regarding implementation of these changes. 

How is "Beginning Construction" Defined for Solar Tax Credits?

Traditionally, the IRS defines “beginning construction” in two main ways: 

1. Physical Work Test: Starting significant physical work (either onsite or offsite custom fabrication). 

1. 5% Safe Harbor Test: Incurring at least 5% of total project costs and receiving the materials. 

⚠️ Due to the recent executive order, these definitions could change. We strongly recommend consulting with a tax expert before making assumptions based on traditional rules. 

What this could mean for your project: 

• The July 4, 2026 construction deadline remains critical
  
• Safe harbor provisions may become more restrictive
• Early action is even more essential given potential regulatory changes 
• Consider accelerating project timelines to avoid regulatory uncertainty 

Why This Matters for Your Business

For commercial solar, the ITC can cover 30% of total project costs, offering potential tax savings of hundreds of thousands of dollars. But with the recent legislative and executive changes, timing is everything. 

What are the Two Options to Secure the Full 30% ITC?

Option 1: Begin Construction by July 4, 2026 

• Qualify for the full 30% ITC by starting construction or meeting safe harbor requirements before this date. 

• You traditionally have 4 years to complete the project (subject to changes from the executive order). 

Option 2: Complete Construction by December 31, 2027 

• Even if you start after July 4, 2026, you can still qualify if your project is fully completed and placed in service before this date. 
• Important: These are alternative paths—you only need to meet one, not both.
  
  

  Benefits of Acting Now 

  • Lock in the full 30% Investment Tax Credit 
  • Offset rising commercial electricity costs 
  • Take advantage of current equipment and labor pricing 
  • Maximize long-term ROI and cash flow 
  
  What Qualifies for the ITC: The credit covers solar panels, mounting systems, inverters, electrical components, installation labor, and energy storage systems when paired with solar installations. 

Why is Immediate Action Required for Commercial Projects?

Commercial solar projects are more complex than residential ones and require longer timelines. Delaying could mean missing the credit entirely. 

Common Project Delays: 

• Engineering complexity (load studies, structural analysis) 

• Permitting (can take 6–12 months for approval) 

• Utility interconnection (lengthy coordination with utility providers) 

• Procurement (longer lead times for commercial-grade equipment) 

• Construction scheduling (must coordinate around business operations)
   
• Industry capacity (bottlenecks as the deadline nears)  

Frequently Asked Questions: Commercial Solar Tax Credit Changes

When do the commercial solar tax credits expire?

The 30% ITC for commercial solar projects is sunsetting on December 31, 2027. However, projects that are safe-harbored by July 4, 2026, will have until December 31, 2030, to be completed and still qualify for the full 30% credit.

What qualifies as "beginning construction" for the solar ITC?

The IRS traditionally uses two tests: the Physical Work Test (starting significant onsite or offsite work) or the 5% Safe Harbor Test (incurring at least 5% of total project costs). However, recent 2025 executive orders may tighten these definitions.

How much is the commercial solar investment tax credit in 2025?

The commercial ITC remains at 30% of the total project cost, including panels, inverters, mounting, and energy storage systems, provided construction deadlines are met.

Next Steps with Harvest Solar

At Harvest Solar, we understand the complexity of commercial solar projects and are committed to helping businesses secure the Investment Tax Credit before it expires. Given the extended timeline required for commercial installations, we strongly encourage businesses to act quickly, as we expect a significant rush of projects as the July 4, 2026 deadline approaches. 

• Contact Harvest Solar immediately for your commercial solar assessment 
• Schedule your feasibility study to determine project scope and timeline 
• Review your electrical infrastructure and utility requirements 
• Begin the permitting process as early as possible to avoid delays 

The window for maximizing your commercial solar investment with federal tax credits is limited, and the development timeline for commercial projects requires immediate action.

Important Disclaimer 

Harvest Solar is not a tax advisory firm or legal counsel. This information is provided for general educational purposes only. The interpretation of tax law can be complex and may evolve rapidly as new regulations, executive orders, and guidance are developed. Given the recent executive order signed July 7, 2025, and ongoing regulatory changes, the landscape for solar tax credits is particularly fluid. We strongly recommend consulting with qualified tax professionals and legal counsel who specialize in renewable energy tax law to understand how these changes specifically impact your business tax situation and to ensure you receive accurate, up-to-date advice for your circumstances.