US President Donald Trump signed an order on the evening of 6 August 2026 that puts a 15% tax on imported polysilicon, starting 4 December. Polysilicon is an ultra-pure form of silicon used to make both computer chips and solar panels. The order also sets minimum prices for these products entering the US: $21 per kilogram for raw polysilicon, $100 per kilogram for partially processed forms called ingots and wafers, $0.22 per watt for solar cells, and $0.38 per watt for finished solar panels. The plan came from Commerce Secretary Howard Lutnick. The Guardian

A tariff is a tax on imported goods that makes them more expensive, encouraging buyers to purchase from domestic producers instead. The administration says this tariff will help American companies that make chips and solar panels compete with China on artificial intelligence and clean energy.

The order also lets the Commerce Department create a program to reward companies that build new polysilicon factories in the US. Right now, the country has only two major polysilicon plants: Hemlock Semiconductor in Michigan, run jointly by Corning and Japan's Shin-Etsu Handotai, and a Wacker Chemie facility in Tennessee. The Guardian

The decision follows an investigation started by the Commerce Secretary on 1 July 2025 under a law called Section 232, which lets the government restrict imports it considers a threat to national security. The government asked for public comments through a Federal Register notice published on 16 July 2025. Federal Register Reuters reported on 4 August that the administration was preparing price floors and tariffs, and on 5 August that a 15% tariff would come as early as 6 August. Reuters

This is not the first time the US has used trade rules on these products. In 2024, the President directed the US Trade Representative (USTR) to raise tariffs on solar cells to 50%. Federal Register The 2025 USTR Trade Policy Agenda extended a system that allows a limited amount of solar cells to enter at a lower tariff rate for four more years, with a higher cap on that amount. USTR A June 2026 USTR report found that forced labor is widespread in polysilicon production and traced its use through the solar supply chain, including cells and panels. USTR

Under Executive Order 14257, as amended, items classified under specific sections of the US tariff schedule are excluded from the new tariff per ANNEX II. White House

China's Ministry of Foreign Affairs condemned the tariff, accusing the US of "overstretching the concept of national security and abusing state power to go after Chinese businesses." The Guardian The criticism arrives as China's exports surged 23.9% year-on-year in dollar terms in July, driven by shipments of AI-related products.

The broader context here is that three different trade-policy tools have been aimed at pieces of the polysilicon supply chain over the years, and this order rolls them into one. National-security investigations, actions addressing forced labor, and older rules against unfairly cheap imports each previously targeted separate parts of the chain from raw silicon to finished solar panels. The new order combines them into a single package: a tariff, minimum prices, and incentives for domestic factory investment. The approach of pairing penalties on imports with rewards for domestic production mirrors the CHIPS Act, which subsidized semiconductor manufacturing in the US, but applies it to a material that sits at the crossroads of both the AI boom and the shift to renewable energy.

The production base the policy is meant to protect is small. Two plants make up all of the country's major polysilicon capacity. Hemlock and Wacker Chemie's Tennessee operation would be the main domestic beneficiaries of the incentive program, but building polysilicon production takes a lot of money and time. The December start date gives importers roughly four months to adjust supply contracts, which in practice may mean shipping in extra inventory before the tariff takes hold.

China's 23.9% July export surge, driven by AI-related products, sharpens the competitive gap the tariff is designed to address. Whether a 15% tariff and minimum prices can close that gap depends on whether the incentive program draws enough investment to build capacity that does not yet exist at meaningful scale in the United States. The history of solar-cell tariffs escalating from 50% under the prior administration to the current price-floor system suggests a policy trajectory toward progressively tighter import restrictions, not a one-time adjustment.