The renewable energy industry is facing another significant tariff development. On August 6, 2026, a Presidential Proclamation confirmed that the government’s Section 232 investigation into polysilicon imports was targeting the solar industry and imposed new restrictions on imported polysilicon and downstream solar products, including wafers, solar cells and modules. The measures are scheduled to take effect on December 4, 2026.
What Does This Mean for the Solar Industry?
The new action imposes minimum import prices (MIPs) on polysilicon and its derivative products, and a separate 15% ad valorem tariff on the derivative products only (polysilicon ingots, wafers, solar cells and modules). Raw polysilicon itself is subject to the MIP mechanism but is exempt from the 15% ad valorem tariff. The announcement represents a shift from prior tariff treatment for some solar products, including replacing the expired Section 201 safeguard tariffs on solar cells and modules, and is likely to increase costs for imported solar equipment.
The 15% ad valorem tariff applies broadly to covered polysilicon derivatives, but several U.S. trading partners receive more favorable treatment. For example, imports from the United Kingdom are subject to a reduced 10% rate, and for Japan, South Korea, Taiwan, Switzerland, Liechtenstein and the European Union, the tariff is capped so that the tariff amount, plus the existing standard duty rate (MFN/Column 1) does not exceed 15% in total.
How Does the Minimum Import Price Mechanism Work?
The MIP mechanism sets a floor price for covered products rather than a flat tariff rate. Under the proclamation, the following MIPs apply beginning December 4, 2026: $21 per kilogram for polysilicon, $100 per kilogram for polysilicon ingots and wafers, $0.22 per watt for solar cells and $0.38 per watt for solar modules.
At entry, importers must submit documentation to U.S. Customs and Border Protection (CBP) showing that (1) the product’s entered value meets or exceeds the applicable MIP, and (2) the imported product, or any downstream product made with it, will be resold in the United States at or above the applicable MIP (a requirement waived for sales made under fixed-price, time-limited contracts entered into before August 6, 2026).
If the entered value falls short of the applicable MIP, a specific tariff equal to the shortfall applies in addition to the product’s other duties. If an importer fails to submit the required documentation at all, the full MIP amount applies as a specific tariff. For derivative products, this specific tariff stacks on top of the separate 15% ad valorem tariff described above.
CBP is directed to monitor the accuracy of importer certifications, and importers found to have submitted materially inaccurate documentation, or to have materially failed to comply with their certification obligations, face permanent debarment from importing polysilicon and its derivatives, in addition to standard customs penalties.
The proclamation further directs Commerce to monitor for companies stockpiling polysilicon or its derivatives ahead of the December 4, 2026 effective date. If Commerce determines that a company is engaged in stockpiling, it is instructed to coordinate with CBP to restrict that company's imports.
Commerce also retains authority to adjust the MIP levels over time to reflect market conditions or other factors affecting fair market value, so the price floors are not necessarily fixed through the life of the program.
Beyond the tariff measures, the proclamation includes an onshoring mechanism under which the Secretary of Commerce may waive the tariffs for a company that commits to building domestic production facilities.
Of particular concern, the proclamation indicates that these tariffs may be stacked with other existing trade measures, including antidumping and countervailing duties (AD/CVD), Section 232 steel and aluminum tariffs and Section 301 China tariffs. Notably, Section 301 tariffs imposed in connection with the forced labor action against certain trading partners are not stacked with Section 232 tariffs, as goods subject to Section 232 tariffs are expressly excluded from that action.
Key Considerations for Developers, Investors and Suppliers
While the new Section 232 action does not take effect until December 4, 2026, the downstream solar industry should begin preparing now. Companies involved in utility-scale solar projects, distributed generation, energy storage and related supply chains should assess how the new tariffs may affect procurement strategies, project economics and contractual risk allocation. Organizations should also review product sourcing, country-of-origin determinations and customs compliance procedures to understand potential exposure.
In addition, project stakeholders should revisit contracting provisions that address tariff risk, cost-sharing mechanisms, pricing adjustments, change of law provisions and termination rights in the event of significant regulatory changes.
Looking Ahead
As U.S. tariff policy continues to evolve, renewable energy companies should remain focused on supply chain flexibility, customs compliance and proactive risk management. The latest Section 232 action underscores the increasing intersection of trade policy and energy development, making it more important than ever to evaluate potential tariff impacts early in project planning and transaction diligence.
For additional background on the solar tariff landscape, see our prior coverage, “Navigating the Solarscape: Our Handy Solar Tariffs Cheat Sheet,” and “Tariff Strategies For The US Renewable Energy Sector.”