A US price floor for imported solar panels sits above what American panels sell for, and First Solar just hit a one-year low

A presidential proclamation signed August 6, 2026 under Section 232 imposes, from December 4, 2026, a 15% tariff on imported polysilicon and its derivatives — ingots, wafers, solar cells and modules — plus minimum import prices of $21/kg for polysilicon, $100/kg for ingots and wafers, $0.22 per watt for cells and $0.38 per watt for modules, with a specific duty covering any shortfall below the floor. Rates are 10% for the UK and capped at 15% combined with existing duties for Japan, South Korea, Taiwan, Switzerland and the EU. Companies with approved US onshoring plans can import duty-free.

For scale: SMM put Chinese n-type polysilicon at about $4.76–4.88/kg and Chinese TOPCon modules at about $0.105 per watt on August 6. Solar Power World reported in August that US-made panels averaged 31¢ per watt, Southeast Asian panels 27¢ and Indian-assembled panels 14¢. Only Hemlock Semiconductor and Wacker Chemie make polysilicon in the US; China holds 93.5% of global capacity. A Commerce temporary final rule issued September 22 and published September 24 caps weekly imports by importers registered after August 6 (for example, 55 modules a week) and lets Commerce restrict existing importers whose volumes run well above historical levels, to stop stockpiling before December 4.

First Solar closed at $172.16 on September 24, 2026, down 10.3% on the day, its lowest close in a year, 31% below its August 7 close of $250.05 and 46% below its June 3 close of $318.25. The drop followed First Solar’s withdrawal of a patent complaint at the US International Trade Commission and came as the 10-year Treasury yield rose above 5%. T1 Energy closed at $3.81 (35% below August 7) and Canadian Solar at $10.95 (31% below). Wacker Chemie closed at €87.10, 9% below its August 6 close.

Opportunity

The obvious reading is that US solar equities are falling on rates and demand, and that tariffs only raise the cost of a product whose buyers are already under pressure. That reading treats the domestic industry as one trade, which the rule does not.

The floor hurts assemblers that import cells: a $0.22 per watt cell floor raises the input cost of every US module plant running on foreign cells, which is a reasonable explanation for T1 Energy’s and Canadian Solar’s falls. It does the opposite for companies that need no imported silicon at all. First Solar’s cadmium-telluride panels use no polysilicon, and Hemlock and Wacker’s Tennessee plant are the only US polysilicon sources while the import floor sits at more than four times the Chinese price.

Hypothesis: once the $0.38 floor applies, the cheapest imported panel in the US costs more than the average American-made panel did in August, so domestic makers with domestic inputs gain room to raise prices on new contracts rather than merely defend share; the market is selling First Solar with the import-dependent assemblers and pricing the whole group on rates, rather than separating the companies the floor protects from those it taxes.

A second inference: the $21/kg polysilicon floor is the most extreme ratio in the whole schedule, so the most direct beneficiaries may be the two US polysilicon plants rather than any panel maker.

How it could play out

Imports are capped until December 4 by the anti-stockpiling rule → from December 4 imported modules cost at least $0.38 per watt plus tariff → developers sign 2027–2028 supply contracts at prices set against that floor → makers with US cells and silicon, and US polysilicon producers, lift contract prices while import-dependent assemblers are squeezed until their own cell plants run → earnings estimates for the protected group rise and the group separates from the rest of US solar.

The failure path: higher prices and 5% Treasury yields push developers to delay projects, total US installations fall, and a higher price per watt on fewer watts leaves domestic makers no better off.

Questions worth asking

• How much of First Solar’s 2027–2028 output is already sold at fixed prices, and how much is left to be priced against a $0.38 per watt import floor? That share decides whether the floor reaches earnings before 2028.
• What does Hemlock charge US buyers today, and does a $21/kg floor let it and Wacker’s Tennessee plant reprice solar-grade polysilicon for US customers?
• Which module assemblers will have approved onshoring plans before December 4, letting them import duty-free, and which will not?
• How much did developers import before August 6, and how long does that inventory delay the floor’s effect on contract prices?
• Who loses most: which US developers and residential installers carry fixed-price contracts signed on imported-panel costs?

Where to look

• First Solar (FSLR) — US maker using no polysilicon, at its lowest close in a year on September 24, 2026
• Wacker Chemie (WCH.DE) — one of two US polysilicon producers through its Tennessee plant; also a semiconductor-grade supplier
• Corning (GLW) — majority owner of Hemlock Semiconductor, the other US polysilicon maker, though solar is a small part of Corning
• Hanwha Solutions (009830.KS) — parent of Qcells, which is building integrated ingot-to-module production in Georgia
• T1 Energy (TE) and Canadian Solar (CSIQ) — module makers that depend on imported cells until their own cell plants run, the side the cell floor hurts

Thesis check

The price arithmetic is published and dated: the module floor is above the reported average US panel price, the polysilicon floor is more than four times the Chinese price, and the rule starts December 4, 2026. The sell-off since August has hit protected and exposed companies almost equally.

The weak link is demand and contract timing. First Solar sells much of its output years ahead at fixed prices, so a higher floor may not show up for a long time, and 5% Treasury yields raise the financing cost of every solar project, which could shrink the market faster than the floor raises prices.

Sources

White & Case, Aug 2026 · pv magazine USA, Aug 7 2026 · Solar Power World, Aug 2026 · SMM analysis, Aug 2026 · Federal Register (Justia), Sep 24 2026 · Mondaq (Baker Botts), Sep 2026 · Benzinga, Sep 24 2026