US Imposes Tariffs on Polysilicon Imports, Vital for Solar Panels and Chips

US President Donald Trump has signed an order to impose tariffs on imports of polysilicon, a critical material used in solar panels and semiconductors, according to a White House official. The move follows a year-long investigation by the Commerce Department into imports of the material.

Commerce Secretary Howard Lutnick described polysilicon as a "foundational product" for chips. "We're making the products here, but we need the supply chain here. So this will bring the supply chain here," Lutnick told reporters at the White House. He added: "We're setting prices so that the Chinese can't dump anymore, and we're setting tariffs to say build it here. We've got the industry here; it's too small, and it's going to explode under your leadership."

Officials did not immediately disclose the tariff levels or price floors that imported products will face. The Commerce Department initiated the investigation in July 2025 under Section 232 of the Trade Expansion Act of 1962, a provision that allows the president to restrict imports deemed a threat to national security. This is the same authority that was previously used to impose tariffs on steel, aluminium, automobiles and other products.

The investigation did not name specific countries, but China is a major producer of polysilicon and a dominant player in the global solar supply chain. The US has been working to reduce its reliance on Chinese-made components for critical industries, and this tariff order is part of a broader effort to rebuild domestic manufacturing capacity.

Polysilicon is a high-purity form of silicon used in the production of photovoltaic cells for solar panels and semiconductor wafers. The material is essential for the renewable energy sector, which has seen significant growth in the US. However, domestic production of polysilicon is limited, and the country imports a substantial share of its supply from abroad, particularly from Asia.

The Section 232 process has been a point of contention in international trade. Tariffs imposed under this provision, such as those on steel and aluminium, have been challenged by trading partners at the World Trade Organization. Critics argue that the national security justification is often used to protect domestic industries, while supporters say it is necessary to address strategic vulnerabilities.

Since returning to the White House last year, Trump has implemented far-reaching tariff measures against US trading partners. Many of these were struck down by the Supreme Court in February, but tariffs based on Section 232 remain in place. Last month, the president used different legal justifications to impose new tariffs on 60 countries, rebuilding his tariff programme after the court ruling.

The latest tariffs could affect the US solar industry, which relies heavily on imported polysilicon. The administration argues that the measure will encourage domestic production and secure the supply chain for a material critical to both renewable energy and advanced technology.