US Imposes Tariffs and Price Floors on Polysilicon Imports, Reshaping Global Solar Trade

President Donald Trump signed a proclamation on August 6 imposing a 15% tariff on polysilicon derivative products and establishing minimum import prices (MIPs) across the polysilicon supply chain, a move that Xinhua News reports will significantly impact global solar supply chains. The measures, effective December 4, 2026, follow a Commerce Department investigation under Section 232 of the Trade Expansion Act of 1962 that found polysilicon imports threaten US national security.

The New Trade Framework

The White House proclamation establishes a four-tier minimum import price regime: $21 per kilogram for polysilicon, $100 per kilogram for ingots and wafers, $0.22 per watt for solar cells, and $0.38 per watt for solar modules. A 15% ad valorem tariff applies to downstream polysilicon derivatives—ingots, wafers, cells, and modules—though not to raw polysilicon itself, as SMM analysis clarifies.

Country-specific treatment varies. For products from Japan, South Korea, Taiwan, Switzerland, Liechtenstein, and EU member states, the combined tariff rate is capped at 15%. The United Kingdom receives a preferential 10% Section 232 rate. For all other countries—including China—the full 15% applies additively on top of existing duties, according to legal analysis from Wiley Rein LLP.

Legal experts at Troutman Pepper Locke note that combined duties on Chinese-origin solar derivatives could exceed 65% when stacked with existing Section 301 tariffs and antidumping/countervailing duty orders.

A Strategic Industry in Decline

The administration frames the action as essential to national security. “For decades, America has allowed foreign countries to weaken United States producers in the polysilicon sector—eroding our economic and national security,” Trump said in the proclamation. “Today, I am taking action to put a stop to these practices and revitalize the United States polysilicon sector.”

The US share of global polysilicon production has collapsed from 50% in 2005 to less than 2% in 2024, according to the Commerce Department investigation. Only two polysilicon factories operate in the United States—Hemlock Semiconductor in Michigan and Wacker Chemie’s Tennessee facility, as The Guardian reports. Meanwhile, China controls approximately 93.5% of the global polysilicon market, with global production growing more than 270% since 2020 and inventories reaching a record 400,000 tons by the end of 2024.

Industry Reactions

US-based manufacturers have welcomed the measures. “For years, China-linked supply chains dumped below cost and circumvented US laws to undercut American workers and their livelihoods, while creating a strategic vulnerability,” said Mark Widmar, CEO of First Solar, as reported by pv magazine. “This action closes that loophole, and it is built to be enforced.”

Andy Park, Global CEO of Hanwha Qcells, said the decision “balances the reality of where America’s solar energy manufacturing is today while advancing our collective ambition to onshore the entire supply chain from polysilicon to finished panels in the U.S.”

Jon Toomey, president of the Coalition for a Prosperous America, called it a historic step, telling Solar Power World that “for the first time, the United States is protecting the entire solar supply chain with a single action—and rewarding the manufacturers that build here.”

China’s Response

Beijing has strongly condemned the measures. Chinese Foreign Ministry spokesperson Lin Jian said the US is “overstretching the concept of national security, and abusing state power to go after Chinese businesses,” according to Asia Times. “Protectionism will not make the US more competitive,” he added.

Chinese trade experts echoed this sentiment. Huo Jianguo, vice chairperson of the China Society for World Trade Organization Studies, said the Trump administration has “overstretched the concept of national security” and should avoid “rash protectionist moves that serve no one’s interests.” Industry analyst Lu Jinbiao of the China Photovoltaic Industry Association argued the plan would do little to boost US polysilicon output but would raise costs for American solar manufacturers.

The measures come amid a broader escalation in US-China trade tensions over solar and semiconductor supply chains. The new tariffs replace the Section 201 solar safeguard that expired in February 2026 and follow a similar Section 232 action on semiconductors in January.

Market Implications

The price floors sit far above current Asian market levels. According to SMM analysis, the US polysilicon MIP of $21/kg is approximately 4.3–4.4 times current Chinese spot prices for n-type polysilicon. The module MIP of $0.38/W is about 3.6 times China port FOB prices, and the cell MIP of $0.22/W is roughly 5.6 times Chinese export prices.

The measures could redirect solar products originally destined for the US to other markets, intensifying competition in Europe, Latin America, and the Middle East. Moustafa Ramadan, head of market research at PV Tech Research, described the move as “one of the biggest events in the US solar landscape,” telling pv-tech.org that “it will change how module procurement works in the US entirely.”

Onshoring Incentives

The proclamation also authorizes the Commerce Secretary to establish an onshoring incentive program, allowing companies that commit to building US polysilicon, ingot, wafer, or cell production facilities to import necessary equipment and covered products duty-free during construction. Construction must begin by January 20, 2029, and companies must demonstrate commercially reasonable timelines and production projections.

What to Watch

As the December 4 effective date approaches, several questions remain: how the Commerce Department will define eligibility under the onshoring program, whether US wafer and cell capacity can come online on schedule, and whether trading partners will adopt “substantially equivalent” MIP systems to qualify for tariff adjustments. The interaction between these measures and the phase-down of federal clean energy tax credits could create significant policy mismatches in 2028–2029, potentially squeezing project economics even as domestic manufacturing receives unprecedented protection.

For now, the United States is moving decisively to rebuild its polysilicon and solar manufacturing base—a shift that will reverberate through global supply chains for years to come.