The White House has introduced new trade measures aimed at strengthening U.S. solar and semiconductor supply chains and reducing dependence on China. U.S. President Donald Trump on Thursday imposed a 15% tariff on products made from polysilicon, along with minimum import prices for polysilicon and several solar products. The measures target a key raw material used in both semiconductor and solar manufacturing.

Trump issued the proclamation under Section 232 of the Trade Expansion Act of 1962. The move seeks to support domestic production and help the United States compete with China in areas linked to artificial intelligence, energy and national security. The order said, "The plan of action in this proclamation will, among other things, help ensure the commercial viability of United States production of polysilicon and its derivatives that is necessary to meet United States economic and national security requirements."

Polysilicon is an ultra-pure form of silicon that forms the starting point for both solar and semiconductor production. Manufacturers use silicon wafers to make solar cells. They then assemble the cells into solar panels that are used in energy projects. The material also plays an important role in the semiconductor supply chain.

U.S. solar manufacturers have accused Chinese competitors for years of flooding the American market with low-priced solar panels. They have also alleged that Chinese companies receive unfair government subsidies and shift manufacturing to other countries to avoid U.S. tariffs. The latest measures are intended to give American producers greater protection from such competition.

The United States currently has two polysilicon factories. Hemlock Semiconductor operates a plant in Michigan and is a joint venture between Corning and Japan's Shin-Etsu Handotai. Munich-based Wacker Chemie operates another factory in Tennessee. Corning welcomed the new measures and said they would support further investment in the United States. A Corning spokesperson said, "Today's decision encourages continued investment in U.S. capacity and supports long-term U.S. competitiveness," Wacker said it was reviewing the actions to fully understand their impact.

The company also highlighted the importance of the decision for the country's technology and security needs. Wacker said, "We appreciate the Administration's continued engagement on the issue given the ramifications for semiconductor supply chain resilience, advanced computing infrastructure, and broader U.S. defence and security interests," the company said in a statement.

The solar industry also plays a role in supporting domestic semiconductor production. Strong demand for polysilicon from solar manufacturers helps maintain production capacity for the material needed by chipmakers. According to the Semiconductor Industry Association, the semiconductor sector represents 2.4% of global polysilicon demand.

U.S. solar manufacturing has grown since Congress introduced tax incentives in 2022. Much of this expansion has focused on assembling solar panels. American manufacturers still rely heavily on imported wafers and solar cells. Building domestic capacity for these products requires more time and investment.

Several companies operating solar factories in the United States welcomed Trump's announcement. These include T1 Energy, First Solar and Qcells, the U.S. solar division of South Korea's Hanwha. T1 Energy CEO Dan Barcelo described the decision as a major boost for domestic manufacturing. "This is a decisive win for advanced American manufacturing and investment in domestic energy supply chains," Dan Barcelo, CEO of T1 Energy, said in a statement. T1 already operates a solar panel plant in Texas and is investing $510 million in a solar cell factory.

The new trade protections will come into effect on December 4, according to the White House. Trade attorney Tim Brightbill of Wiley Rein, who has brought several trade cases against Chinese solar companies, warned that the gap before implementation could encourage companies to increase imports in the coming months. Solar companies that purchase panels have argued that the delay is necessary to give them time to adjust their supply contracts to higher prices.

The White House has also established specific minimum import prices for several products. Under the new plan, imported polysilicon will face a minimum price of $21 per kilogram. The minimum price for polysilicon ingots and wafers will be $100 per kilogram. Solar cells will have a minimum import price of $0.22 per watt, while solar modules, or panels, will have a minimum price of $0.38 per watt.

Alongside the tariffs and price floors, the proclamation grants the Commerce Department authority to launch an incentive programme for companies that invest in U.S. factories producing polysilicon or products made from it. The administration believes this combination can encourage more domestic production while protecting existing American manufacturers.

The hybrid approach of combining minimum import prices with tariffs was first reported by Reuters. The new policy marks another step by the Trump administration to protect strategic industries and build domestic supply chains for technologies considered important to U.S. economic and national security interests.