The United States imposes 15 per cent tariffs on polysilicon

The United States is introducing 15 per cent tariffs on polysilicon products. The measures, signed by President Donald Trump, take effect on 4 December.

Alongside the tariffs come minimum import prices. Polysilicon may not be imported below 21 dollars per kilogram. For ingots and wafers the threshold is 100 dollars per kilogram, for solar cells 0.22 dollars per watt and for modules 0.38 dollars per watt.

The White House has added a clause against stockpiling. If companies accumulate polysilicon before 4 December, imports will be restricted.

An almost entirely Chinese market

Polysilicon is the raw material of solar power and semiconductors. In 2024 Chinese companies accounted for more than 96 per cent of world production, while the United States stopped at 0.8 per cent.

The American producers named are Hemlock Semiconductor, part of the Corning group, and Wacker Chemie, headquartered in Munich. Public incentives are promised to companies that invest in domestic production.

The stated aim is to reduce dependence on a single supplier in two sectors considered strategic. The cost of the operation, however, falls on American installers and panel buyers, who will pay more for the raw material.

There is also a question of timing. Building polysilicon production capacity takes years and heavy investment, while the minimum prices apply from December.

For Europe and Switzerland the effect is indirect but real. If Chinese material finds less room in the United States, part of the supply will spill into other markets, with possible downward pressure on prices outside the American area.