Trump to impose 15% tariff on polysilicon products in China probe

The Trump administration plans to impose a 15 percent tariff on polysilicon derivative products and unveil the results of its Section 232 investigation into foreign imports as soon as Thursday, four sources familiar with the matter told Reuters.

The measure targets China, which dominates global polysilicon output, and would add a series of price floors on products made from the material, the sources said. Polysilicon is the key raw material used in solar panels and semiconductors, making the tariff a direct lever on two of the most contested supply chains in US-China trade.

The Section 232 probe, launched to assess whether foreign polysilicon imports threaten US national security, will determine the scope of the tariff and the price-floor mechanism. The exact dollar value of affected trade has not yet been disclosed, and the administration has not specified which derivative products would fall under the 15 percent rate.

Solar and Chip Supply Chains Face Higher Input Costs

A 15 percent tariff would raise input costs for US solar panel assemblers and semiconductor producers that source polysilicon from China, squeezing margins across the supply chain. US solar developers, already navigating elevated module prices, would face additional pressure as the tariff flows through to panel costs. Semiconductor fabs that rely on imported polysilicon for wafer production would see similar cost increases.

Domestic polysilicon producers stand to benefit from the protectionist measure, as the tariff and price floors would make US-sourced material more competitive against cheaper Chinese imports. The price-floor mechanism, in particular, is designed to prevent Chinese producers from undercutting US output on cost.

The move also risks further escalation in US-China trade tensions. China has historically answered US tariff actions with retaliatory measures on US exports, and the polysilicon tariff follows a pattern of escalating restrictions on Chinese clean-energy and technology inputs. The previous rounds of US tariffs on Chinese goods drew countermeasures that reduced bilateral trade flows, and market participants will watch for a similar response this time.

What Comes Next

The administration is expected to unveil the Section 232 findings as soon as Thursday, which will clarify the tariff's scope and effective date. Market participants will watch for the specific list of polysilicon derivative products covered, the level of the price floors, and any exemptions for US manufacturers that depend on imported material.

If the tariff is applied broadly, US solar installation costs could rise further, potentially slowing project development in a sector already facing supply constraints. If exemptions are granted for domestic manufacturers, the impact would be more contained, though the price floors would still raise costs for importers.

The outcome will also shape how China responds. Beijing has said it will counter US trade measures, and a polysilicon tariff could draw retaliation against US agricultural or technology exports. The Section 232 announcement Thursday will set the stage for the next round of the trade dispute, with solar and semiconductor supply chains at the center of the confrontation.

This article is for informational purposes only and does not constitute investment advice.