If you've been shopping for solar panels by the pallet or truckload, you've probably noticed labels like "45% domestic content" and "FEOC compliant" showing up on listings, including some of ours. They aren't marketing fluff. For the right buyer, they can be worth thousands of dollars in federal tax credits. For other buyers, they don't matter at all. Here's a plain-English breakdown.
What is the domestic content bonus?
The domestic content bonus is an optional add-on to the Section 48E Clean Electricity Investment Credit, the federal tax credit for commercial solar and for third-party-owned systems like leases and PPAs. A project that qualifies earns extra credit on top of its base rate. For most commercial projects that meet prevailing wage and apprenticeship requirements, that means the credit goes from 30% to 40% of eligible project cost. Projects that don't meet those labor requirements get a smaller 2-point bump instead.
On a $500,000 commercial array, that extra 10 points is $50,000. That's why developers and EPCs care so much about where their equipment comes from.
How does a project qualify?
There are two tests, and the project has to pass both:
- Steel and iron: Structural steel and iron in the project must be 100% U.S.-made.
- Manufactured products: A minimum share of the cost of manufactured products (panels, inverters, racking and so on) must be domestic. That threshold depends on when construction begins: 45% for projects that began after June 16, 2025 and before 2026, 50% for projects beginning construction in 2026, and 55% after that.
Treasury publishes a safe harbor table (most recently updated in Notice 2025-08) that assigns a set cost percentage to each component, so developers don't have to dig through every supplier's actual manufacturing costs. It gives more credit to panels built with U.S.-made cells and wafers, not just U.S. assembly.
A panel's percentage isn't the project's percentage
This is the part that trips people up. When a panel is listed as "45% domestic content," that describes the panel itself. Whether a project qualifies is calculated across all the manufactured products in the system. Panels are usually the biggest piece, so high-domestic-content modules do a lot of the work, but the inverters, racking and other components count too. Your tax advisor or engineering team will run the full calculation for your project.
Domestic content vs. FEOC: not the same thing
These two labels often get lumped together, but they answer different questions:
- Domestic content asks where equipment was made. It's optional, and meeting it earns a bonus.
- FEOC (foreign entity of concern) asks who made it. Under the One Big Beautiful Bill Act, solar projects that begin construction after December 31, 2025 have to limit "material assistance" from prohibited foreign entities, primarily Chinese-controlled manufacturers. For projects starting in 2026, at least 40% of the equipment cost must come from non-FEOC sources, and that bar rises over time. This isn't a bonus. Fail it, and the project loses the base credit entirely.
A panel can be FEOC compliant without having much domestic content, and vice versa. Panels that check both boxes, like the Heliene modules we carry, cover both requirements at once.
The clock is running
The One Big Beautiful Bill Act, signed in July 2025, put an end date on Section 48E for solar. Projects that began construction on or before July 4, 2026 keep the longer, pre-existing timeline. Projects that start after that date must be placed in service by December 31, 2027 to claim the credit at all.
The homeowner credit (Section 25D) for systems bought with cash or a loan ended after 2025. So for 2026 and 2027, the domestic content bonus matters mainly to commercial projects, developers finishing safe-harbored projects, and companies offering leases and PPAs.
Do used panels count?
No. Under Treasury's safe harbor, used equipment is assigned a domestic cost percentage of zero. Used panels are still an excellent value for off-grid builds, farms, workshops and self-funded projects where the tax credit isn't the point. They just won't help a project hit a domestic content threshold.
Who has to prove it?
The taxpayer claiming the credit, not the panel seller or installer, certifies domestic content compliance. They attach a signed certification statement to IRS Form 3468 in the first year they claim the bonus, and they need to keep supporting documentation. That's why it matters to buy from a supplier who can hand over the manufacturer's domestic content and FEOC paperwork when you ask for it.
Who should care
- Developers and EPCs finishing projects that began construction by July 4, 2026, or racing to place new projects in service by the end of 2027.
- Commercial and agricultural owners claiming the 48E credit on their own systems.
- Lease and PPA providers claiming 48E on residential systems they own.
If you're buying panels for a home system you're paying for yourself, or for an off-grid project, domestic content probably doesn't change your math. Buy whatever gives you the best watts for the dollar.
Talk to us
We carry domestic content, FEOC-compliant panels by the truckload, alongside our new and tested-used pallets. If you're sourcing for a project that needs the bonus, contact us or call (239) 628-8282. We can get you the manufacturer documentation along with a quote, and we respond to truckload requests within one business day.
This article is general information, not tax or legal advice. Tax credit rules change, and whether a specific project qualifies depends on its details. Talk to a qualified tax professional before making purchasing decisions based on tax credits.