The numbers landed with force. On April 21, 2025, the U.S. Department of Commerce issued final affirmative AD/CVD determinations on crystalline silicon photovoltaic cells and modules from Cambodia, Malaysia, Thailand, and Vietnam. Certain Cambodian producers, penalized for non-cooperation, faced combined rates approaching 3,521%. Even for more cooperative players, the duties were punishing enough to rewrite sourcing assumptions across the industry.
The Squeeze on Low-Value Assembly Operations
For years, the model looked sustainable on paper. Chinese cells arrived in Southeast Asian facilities — many around Phnom Penh or Thailand’s eastern seaboard — for basic framing, junction box attachment, and testing before heading to U.S. ports. Between 2022 and 2024, this route accounted for the majority of U.S. module imports. That flow has now been sharply curtailed.
Customs and Border Protection stepped up scrutiny at Los Angeles and Long Beach. Certificates of Origin tied to minimal local value-add faced rejection. On the ground, the impact varied by company. Hounen Solar and Solar Long in Cambodia took the heaviest hits under adverse facts available (AFA) rules. Jinko Solar’s Malaysian unit secured one of the more moderate outcomes. Trina in Thailand and various Vietnamese operations sat somewhere in between, but still under significant pressure.
This round marked a clear evolution from earlier circumvention cases. Previous inquiries had targeted Chinese-origin components assembled abroad. The 2025 determinations treated the Southeast Asian factories themselves as the subjects of standalone investigations. The distinction matters for compliance teams.
Lobbying Pressure and the Secondary Shift
The Alliance for American Solar Manufacturing and Trade kept the momentum going. After the Southeast Asia duties, the group pushed for action on the next set of rising import sources. Their efforts contributed to new petitions covering India, Indonesia, and Laos.
The response came quickly. On February 24, 2026, Commerce released preliminary CVD determinations for the three countries. India faced headline subsidy margins around 126%, with Indonesia and Laos also seeing substantial figures. Preliminary AD findings followed on April 23, pushing combined cash deposit rates into the 100-234% range depending on the origin. Final rulings are still expected later this year.
What the Import Data Actually Shows
The redirection happened faster than many anticipated. According to SEIA Solar Market Insight tracking, monthly U.S. module imports from the original Southeast Asia Four dropped from an average of roughly 3.8 GW in 2024 to about 1.1 GW in early 2025. Cambodian volumes essentially disappeared. Meanwhile, shares from Indonesia and Laos climbed sharply, reaching over 34% in the same period.
Here is a simplified comparison of key final and preliminary rates (approximate combined exposure):
| Origin | Notable Examples | Combined Duty Range (approx.) | Notes |
|---|---|---|---|
| Cambodia | Hounen / Solar Long | Up to 3,521% | AFA heavy |
| Malaysia | Jinko Solar | 20-250% | Varied |
| Thailand | Trina | 200-800%+ | Significant |
| Vietnam | Multiple | 120-800%+ | Broad |
| India (prelim 2026) | All Others | ~234% | CVD + AD |
| Indonesia/Laos | Various | 100-180% | Preliminary |
Underlying Dynamics
The pattern is familiar but accelerating. Chinese manufacturers had invested heavily in Southeast Asia to navigate earlier China-specific duties. Each new barrier forces fresh relocation, higher localization requirements, and rising sunk costs. U.S. domestic module capacity has expanded impressively, yet cell production remains a bottleneck. This gap keeps assemblers exposed to imported cells and the associated tariff risks.
Project developers have felt the ripple effects. Higher landed costs threaten the economics of some utility-scale pipelines, particularly where margins were already thin.
Risks Looking Ahead (2026–2030)
Several structural challenges stand out.
The circumvention playbook has become well-established at Commerce. Any country seeing a sudden surge in U.S.-bound solar exports now sits on a short watch list. Turkey, Mexico, and parts of North Africa could face scrutiny next.
UFLPA enforcement adds another layer. Polysilicon traceability issues have already caused detentions. Reports of enhanced isotope testing suggest authorities can now probe origins more deeply, even for material that has cleared tariff hurdles.
True localization carries heavy capex demands. Building cell and wafer lines in the U.S. or compliant third countries requires hundreds of millions, against a backdrop of potential IRA policy shifts and elevated local costs. Many firms face an uncomfortable choice: absorb the compliance burden or risk market exclusion.
Finally, demand itself is fragmenting. While Europe, India, and parts of Southeast Asia are growing their own markets, none yet fully compensates for volatility in the world’s largest single buyer.
Practical Compliance Considerations
Companies need more than basic documentation. End-to-end visibility systems that track material origins, processing steps, and actual value-add at each stage have become table stakes. On-site audit capabilities in higher-risk jurisdictions help. Many players are also setting aside meaningful cash buffers for potential retroactive duties and port delays.
The era of easy transshipment workarounds appears to be ending. What replaces it — genuine regional manufacturing depth or continued regulatory whack-a-mole — will shape solar costs and availability for years to come. Supply chain teams that treat intelligence and traceability as core capabilities will likely fare better than those hoping for temporary loopholes.
This assessment draws from public regulatory records and industry data available as of late May 2026. Trade remedies remain subject to final rulings, appeals, and potential policy changes.