President Trump has ordered a 15% tariff on imported products made with polysilicon, a key material for semiconductors and solar panels. The new tariff will take effect on December 4th. The Guardian reports: The executive order signed by the president on Thursday evening 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, an ultra-pure form of silicon, is an important ingredient in making the semiconductors vital for AI processing power, datacentres and solar power generation. US solar factories have long accused Chinese rivals of dumping cheaper panels on the market, which they say have been enabled by excessive government subsidies and by moving manufacturing to other countries to dodge US tariffs. [...] The US has two main polysilicon factories, including Hemlock Semiconductor, which operates a plant in Michigan and is a joint venture between the US tech company Corning and Japan's Shin-Etsu Handotai. The Munich-based Wacker Chemie runs a factory in Tennessee. Trump said in the order that he had accepted recommendations by the commerce secretary, Howard Lutnick, to set minimum import prices of $21 a kilogram for polysilicon, $100 a kilogram for polysilicon ingots and wafers, $0.22 a watt for solar cells, and $0.38 a watt for solar modules or panels. The order also allows the commerce department to create an incentive program for companies that invest in factories to produce polysilicon or derivative products.

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