President Trump signed a proclamation on August 6 imposing a 15% ad valorem tariff on polysilicon and downstream derivative products, along with a minimum import price (MIP) program, effective December 4, 2026. The action invokes Section 232 of the Trade Expansion Act, citing national security concerns tied to semiconductor and solar supply chain resilience. The MIP levels are set at $21/kg for polysilicon, $100/kg for ingots and wafers, $0.22/watt for solar cells, and $0.38/watt for solar modules.
The Commerce Department found that polysilicon imports threaten U.S. national security because the nation's share of global production has plummeted from 50% in 2005 to less than 2% in 2024. Polysilicon is foundational to both semiconductor manufacturing—critical for defense systems, AI chips, and communications—and solar-cell production. The proclamation also authorizes the Commerce Secretary to create an onshoring incentive program for companies investing in domestic polysilicon and derivatives manufacturing capacity.
For semiconductor and solar practitioners, this represents a significant policy shift with 120 days of lead time. Importers must document that all-in costs meet or exceed MIP levels or face specific tariffs equal to the shortfall. Estimates from analysts suggest module price increases of $0.10/watt on average, requiring solar PPAs to rise $4–$5/MWh to offset capex impacts. First Solar and other U.S. makers support the move; expect industry consolidation and near-term pricing pressure through early 2027.