US hits solar supply chain with 15% tariff and minimum import prices

The US is imposing a 15% tariff and minimum import prices across the solar manufacturing supply chain, creating a new working-capital and procurement challenge for companies importing panels, polysilicon and key components.

President Donald Trump signed a proclamation on Thursday covering imported solar-energy materials and equipment. The measures take effect on 4 December, while companies committing to new US manufacturing capacity will be able to seek exemptions.

The policy goes beyond a conventional tariff by placing minimum prices on several stages of the photovoltaic supply chain. Polysilicon will face a floor of US$21 per kilogram, ingots and wafers US$100 per kilogram, solar cells US$0.22 per watt and modules US$0.38 per watt. Importers will be required to certify that sales do not undercut the prescribed levels.

The action has been introduced under Section 232 of the Trade Expansion Act, which allows the US government to restrict imports considered relevant to national security. Washington has increasingly used the mechanism in industries it considers strategically important, including semiconductor manufacturing.

For importers, distributors and project developers, the combination of tariffs and price floors changes more than the final purchase price. Higher landed values can increase the amount of trade finance required for the same shipment and tie up more cash in inventory before modules are installed or sold.

The 4 December implementation date may also encourage buyers to reassess procurement schedules. Businesses accelerating imports ahead of the deadline could temporarily require more inventory funding, letters of credit or other short-term facilities, while those buying after implementation will need to accommodate higher minimum transaction values.

Banks financing the sector will have to monitor product classification, exemption eligibility and changing collateral values. A borrowing base calculated against imported solar inventory may look materially different once regulatory floors and duties affect acquisition costs.

The new action is distinct from the broader US tariff changes already affecting international trade. BCR covered the wider pressure from tariffs across dozens of economies in July. This measure targets a specific industrial supply chain and introduces minimum import pricing alongside the tariff, materially changing the financing economics for solar-related goods.

The policy is intended to reduce US dependence on overseas solar and semiconductor supply chains. For companies still reliant on imported materials, however, the immediate issue will be how much additional liquidity is required to keep goods moving after December.