The US will impose a 15% tariff on polysilicon-based products from 4 December 2026, with minimum import prices (about US$21/kg for polysilicon, US$0.22/W for solar cells, US$0.38/W for modules). The rule targets China, which makes over 96% of world polysilicon. For most Thai SMEs this is indirect: it may raise solar panel and electronics component costs for suppliers and US-bound supply chains. Thai solar installers or exporters to the US should check supplier pricing before the deadline. The US also warned against stockpiling before 4 December.