Will the 2026 tariffs raise solar panel prices? What the import price floors add to an 8 kW system

What Proclamation 11052 sets, line by line

The authority is Section 232 of the Trade Expansion Act of 1962. The President accepted a Commerce Department finding that polysilicon and its derivatives are imported in quantities that threaten national security, and chose two remedies for solar: a minimum import price program and a 15 percent ad valorem duty on ingots, wafers, cells and modules. The proclamation says the new duty replaces a similar but narrower safeguard tariff on solar cells and modules from the first term, one that expired in February 2026. Both remedies apply to goods entered for consumption, or withdrawn from a bonded warehouse for consumption, on or after 12:01 a.m. eastern time on December 4, 2026.

The floors are set in clause 1 and Annex I of the proclamation, and the added duty in clause 4 and heading 9903.45.30 of Annex II. Each floor attaches to specific tariff schedule lines.

Three details in the table matter for a rooftop quote. Raw polysilicon carries a floor but not the 15 percent. Cells and modules each have two statistical lines in the annex, one for the crystalline silicon kind and one for everything else in the subheading, although the Annex II headings describe the goods as polysilicon solar cells and modules. Whether thin-film cells and modules are in scope is therefore a question for Customs and Border Protection. And the cell and module floors are per watt, which makes them directly comparable with the per-watt lines of a cost benchmark. The two kilogram floors are not, because the proclamation gives no conversion from kilograms of wafer to watts of panel.

The 15 percent is not the same for every origin. For products of Japan, South Korea, Taiwan, Switzerland, Liechtenstein and European Union member nations, heading 9903.45.31 sets the ordinary column 1 duty plus the new duty at a total of 15 percent, so a product with a nonzero ordinary rate pays less than 15 percent on top. For products of the United Kingdom the rate is 10 percent. The minimum import prices in clause 1 are written without an origin split. Clause 1(b) lets the Secretary of Commerce adjust the floors from time to time to reflect market conditions, so the $0.22 and $0.38 figures are the starting values, not fixed terms. Paragraph 10 also authorizes the Secretary and the Trade Representative to arrange different treatment for trading partners that adopt a substantially equivalent floor.

How the floor is collected: entered value, gap and paperwork

A minimum import price here is not a control on what the homeowner pays. It is a customs rule applied to the value declared when the goods enter the country, the entered value. Clause 2 lets an importer submit documentation at entry that certifies one of two things: that the first arm's-length sale of the goods in the United States, or of downstream products made from them, will be at or above the floor, or that the first sale falls under fixed terms in a contract signed before August 6, 2026. Clauses 2(b) and 2(c) then divide the outcomes. An importer who submits no documentation owes a specific tariff equal to the whole floor on every watt. An importer who documents the sale but entered the goods below the floor owes a specific tariff equal to the difference between the entered value and the floor. A documented entry at or above the floor owes no specific tariff.

In tariff-schedule terms, headings 9903.45.33 to 9903.45.36 carry the full specific rates of $21 per kilogram, $100 per kilogram, $0.22 per watt and $0.38 per watt. U.S. note 42 says those headings apply to entries without documentation, and to documented entries where Customs and Border Protection must adjust the duty as the proclamation provides. They do not apply when the entered value meets or exceeds the rate and one of three conditions holds: the product is not resold and downstream products made from it sell at or above their own rate, the product is resold at or above its own rate, or it is resold under a time-limited fixed-terms contract signed before August 6, 2026.

The 15 percent is a separate charge. Clause 4 imposes it as an additional ad valorem duty on the entered value, and clause 5 says duties under the proclamation apply in addition to other duties, taxes, fees and charges unless the proclamation says otherwise. Note 42 adds that antidumping, countervailing and other duties applicable to the goods continue to be imposed. A duty that was payable before December 4 stays payable after it, so it cancels out of any before-and-after comparison.

Put those pieces together and the added cost per watt of a covered product depends on one number, its entered value. Below the floor, the addition is the specific tariff for the gap plus 15 percent of the entered value, which simplifies to the floor minus 85 percent of the entered value. At or above the floor, with documentation filed, the addition is 15 percent of the entered value. The result is bounded at both ends. As the entered value approaches zero, the addition approaches the full floor, $0.22 per watt for a cell and $0.38 per watt for a module. At an entered value equal to the floor, it falls to 15 percent of the floor, $0.033 per cell watt and $0.057 per module watt. Every cent of entered value below the floor lowers the addition by 0.85 cents.

The documentation route carries a promise about later sales, and Customs polices it. Under clause 3, an importer found to have filed materially inaccurate documentation faces a permanent bar, with its affiliates, on importing these products. Clause 8 allows manufacturing drawback of the new duties on articles that are not covered by an antidumping or countervailing duty order, are products of the listed trade partners (the United Kingdom, the European Union, Japan, South Korea, Switzerland, Liechtenstein, Mexico and Canada, and any partner that concludes a trade and security agreement), and contain only polysilicon from a partner country. Those are importer-side mechanics, and a homeowner meets them only as a price.

Cells, modules and the build in your quote

A rooftop buyer meets these floors through a module datasheet, not a customs entry, so the useful question is which annex line the goods in the quote crossed the border under. Annex I puts cells in subheading 8541.42.00 and modules, described as photovoltaic cells assembled in modules or made up into panels, in 8541.43.00. A module assembled in the United States from imported cells never enters as a module. The cells enter as cells, and the cell floor is the one that binds. A module assembled abroad enters as a module and meets the module floor. A module made in the United States from U.S.-made cells brings no cells or modules across the border, though any imported wafers or ingots in its chain carry the $100 per kilogram floor and the 15 percent.

The benchmark build has one wrinkle. A U.S. module maker that imports cells below the floor and documents the entry under clause 2(a) certifies that the first arm's-length sale of the imported goods, or of downstream products made from them, will be at or above the applicable minimum import price, and for a module that price is $0.38 per watt. U.S. note 42(a)(1) states the same downstream test, but only for goods already entered at or above the floor; for a cell entered below it, the certification comes from clause 2(a) and the gap is collected under clause 2(c). Read literally, the maker is also promising to sell its modules at or above $0.38 per watt. Whether that promise adds anything depends on the module's price before the floors. The cell duties add $0.1338 to $0.1491 per module watt in the next sections, so the $0.38 promise only binds for a maker whose module sold below $0.38 minus that addition, about $0.246 or $0.231 per watt. Above that price, the cell arithmetic stands. Below it, the documented route forces modules up to $0.38, which adds more than the cell arithmetic alone. The model file's comment on its module line and the module line recomputed from its own inputs disagree by an amount the file does not explain, so no module price before the floors is used here and the threshold is not tested against one. The $1,178 to $1,312 figures hold if the module's price before the floors is at or above the threshold, and the addition is larger below it. A maker that filed no documentation would instead owe the full $0.22 on every cell watt.

Annex I states that its product descriptions are for information only and are not intended to limit the scope of the Section 232 action, and it refers scope questions to Customs and Border Protection. A contract signed before August 6, 2026 is the second documentation route in clause 2(a). It concerns the importer's own sale contract, not the homeowner's installation contract, so the date a homeowner signs does not decide whether the floor reaches the equipment on the roof.

The cell and module lines inside the $2.95 benchmark

The benchmark is a modeled system, which is what makes a line-by-line estimate possible. The Department of Energy's 2025 Q1 residential case is an 8 kW system of twenty 400 W modules on a pitched roof, with microinverters, priced at $2.95 per watt direct current in 2024 dollars, or $23,600. The model describes its module as a monofacial crystalline silicon module assembled in the United States with cells imported from Southeast Asia, a domestic backsheet and junction boxes, and most other components imported from China. That is the build in which the cell floor, not the module floor, binds. The inputs sit in the model's residential data file, RPV 2025Q1.txt.

Cells enter the model as two prices per watt of cell: $0.08772 before market distortions and $0.1053 after, a ratio of 1.2004. The file's note on the line says the cells carry no Section 201 tariff because of the tariff-rate quota, but that some antidumping and countervailing duty is paid. Those deposits are assessed on the entered value and are not part of it, which suggests that $0.08772 is the closer stand-in for an entered value and $0.1053 the stand-in for the whole price before the proclamation. That is an inference from the file's note, not a statement in it, so both figures are carried through the arithmetic.

A watt of module needs more than a watt of cells. The model's cell-to-module factor is 0.985 and its module yield loss is 1 percent, so each module watt uses 1 divided by 0.985 and by 0.99, or 1.0255 cell watts. At the model's two prices that is $0.090 to $0.108 of cells per module watt, 3.7 percent of the $2.95 line at the higher price. The $0.22 floor is 2.1 to 2.5 times the model's cell prices.

The two markups matter because the model applies them to the module's modeled price. An added dollar of module cost reaches the system price as $1.10. The model's 15 percent developer profit is computed on the undistorted costs and does not scale with the added duty, so it is left out of the arithmetic below. An installer that prices its margin on the higher equipment cost would pass on more.

Summing the model's published inputs reproduces the 2025 Q1 totals, $2.78 for the minimum sustainable price and $2.95 for the modeled market price, so the cell inputs above sit inside a model that closes to DOE's own figures. The benchmark page lists no edition later than 2025 Q1 as of November 3, 2026, and the model file is dated November 13, 2025.

Floor minus price: the 8 kW arithmetic for imported cells

Start with the model's cell price of $0.1053 per watt. The gap to the $0.22 floor is $0.1147. Fifteen percent of the entered value adds $0.0158. The addition is $0.1305 per cell watt, which also equals 0.22 minus 0.85 times 0.1053. Multiplying by 1.0255 cell watts per module watt gives $0.1338 per module watt, and multiplying by 1.10 for the model's hardware markups gives $0.1472 per system watt. Across 8,000 watts that is $1,178, or 4.99 percent of $23,600.

Treat $0.08772 as the entered value and the gap is $0.1323, the 15 percent is $0.0132, and the addition is $0.1454 per cell watt, $0.1491 per module watt and $0.1641 per system watt. On 8 kW that is $1,312, or 5.56 percent. Taking the model's two cell prices as the entered values, the benchmark build moves by $1,178 to $1,312, from $23,600 to between $24,778 and $24,912.

In proportion, the cell line is small and the increase is not. At the model's higher cell price, the addition of $0.1338 per module watt is 124 percent of the cell line's $0.108. At the lower entered value it is 138 percent of the cell line. Against the whole $2.95 system line the same addition is 4.5 to 5.1 percent before the hardware markups and 5.0 to 5.6 percent after them. A cell cost that more than doubles, from $0.108 to between $0.242 and $0.257 per module watt, is what moves a small line by this much, and the rest of the system, from the inverter to the labor, does not change in this arithmetic.

The grid has two ends. A cell entered at $0.05 per watt, below the model's prices, adds $0.1775 per cell watt and $1,602 on 8 kW. A cell entered at $0.22 or more adds only the 15 percent, $0.033 or more per cell watt, and $298 on 8 kW at the floor. Between the ends, each cent per watt of entered value removes 0.85 cents per watt of addition, about $77 on an 8 kW system.

The floor also sets the importer's landed cost almost regardless of the invoice. Landed cost is the entered value, plus the gap, plus 15 percent of the entered value, which is $0.22 plus 15 percent of the entered value. For any entered value under the floor, a cell's landed cost therefore falls between $0.22 and $0.253 per watt before freight, handling and any other duty. The model's cell prices land at $0.2332 and $0.2358. What differs from one importer to the next is the starting point, and the starting point decides the size of the increase. The grid is an illustration with its inputs printed. The anchor for the estimate is the model's cell price, because the DOE benchmark is the national comparison line for rooftop quotes.

A finished module crossing the border

For a module made abroad the floor is $0.38 per watt and the same rule applies to the module's entered value. A module entered at the floor pays only the 15 percent, $0.057 per watt, which puts it at $0.437 landed before any other duty. That is $456 on 8 kW, or $502 with the model's 10 percent hardware markups. A module entered at $0.30 owes a gap of $0.08 plus $0.045 for the 15 percent, $0.125 per watt, which is $1,100 on 8 kW with the markups.

Entered values for finished modules do not appear on a quote, and each row is a separate case. The exposure is largest where the entered value is lowest, which is the incentive the floor is built to remove. Modules entered between $0.30 and $0.38 per watt, the band just under the floor, carry $502 to $1,100 on 8 kW. Modules entered at $0.20 or $0.15 carry $1,848 and $2,222.

Goods that already meet their floor still pay the 15 percent. An entry at the floor adds $0.057 per module watt or $0.033 per cell watt, so a module entered at $0.38 lands at $0.437 and a cell entered at $0.22 lands at $0.253, before freight and any other duty. That is the lowest addition the rule can produce for a product priced at or above its floor, and it grows with the entered value.

What the arithmetic cannot see

Timing comes first. The floors bite on entries from December 4, 2026. Modules and cells that entered earlier carry none of this, and installers and distributors hold stock, so a quote written in November may describe equipment that entered before the floors. The Commerce Department's temporary final rule, 15 CFR part 705 at 91 FR 60505, runs from September 22 through December 3, 2026 and targets the rush. Importers whose volumes run substantially above their historic averages can be barred from entering these goods until December 4, subject to a waiver application, and importers registered on or after August 6 are capped at 2,000 cells (8541.42.00) or 55 modules (8541.43.00) a week unless Commerce approves more.

Pass-through comes second. Nothing in the proclamation requires a seller to raise its price by the addition. The estimate assumes the whole addition reaches the system price with the model's 10 percent hardware markups. An installer that absorbs part of it lowers the figure, and one that applies its normal margin to the higher equipment cost raises it. A quote $0.15 per watt above the benchmark line after December is therefore no longer unexplained on its own.

The scope of the proclamation is narrow. Annex I lists polysilicon, ingots, wafers, cells and modules. Inverters, racking, wiring and batteries are not in it. The DOE model carries Section 301 duties of 25 percent on a number of imported items, including module frames, rails and clamps, as modeled for 2025 Q1, and the proclamation does not touch that treatment.

Status matters too. As of November 3, 2026 the Federal Register's listing of documents mentioning polysilicon shows nothing newer than the September 24, 2026 stockpiling rule, and the proclamation remains in force with its December 4 effective date. Clause 1(b) lets the Secretary change the floors, and clause 16 says that if a court holds any fee, duty, tariff or program invalid, the remainder continues in effect. The floors are policy made by proclamation and can move, so the arithmetic is worth repeating with whatever values apply when your equipment is ordered.

Reading a quote written before or after December 4

Start with the build. The equipment list or module datasheet names the module maker and may name the country where the cells and modules are made; if it does not, ask the installer in writing. A module marked as made in the United States with cells from abroad is the benchmark build, and the cell tables apply. A module made abroad is the finished-module table. A module made in the United States from U.S.-made cells is outside the per-watt arithmetic here.

Then ask when the equipment enters the country, because that decides which side of December 4 the cost falls on. If the contract is fixed-price and the equipment is already in the installer's warehouse, the floors do not touch your price. If the equipment ships after December 4 and the contract allows escalation, the installer may be entitled to pass the cost along, and the contract language that governs it is covered in the guide to adders and change orders. A fixed-price contract normally leaves that risk with the installer, and a tariff clause should come with a formula, a cap and a notice period in writing.

The price-per-watt test is unchanged, with one new caution. The cost-per-watt worksheet compares a quote with the $2.95 benchmark, which is a Q1 2025 figure in 2024 dollars that predates the floors. The reconciliation of the published price benchmarks explains why quotes sit at different distances from it. A proposal that rises by $1,178 to $1,312 on 8 kW between a September and a December version for the same equipment is consistent with the floors. A proposal that rises by $5,000 needs a different explanation, and the quote red flags guide lists the usual ones.

One 8 kW proposal, signed two ways

A hypothetical proposal prices an 8 kW system at $23,600, the benchmark line, with 400 W modules assembled in the United States from imported cells. Signed at a fixed price in October, with the modules already delivered to the installer's warehouse before December 4, the proposal carries none of the floor, because the cells entered before the floors took effect.

The same proposal re-issued in January with modules from a later shipment, and with the cells entered at the model's prices, would rise by $1,178 to $1,312, to between $24,778 and $24,912. If the contract allowed a tariff escalation capped at 3 percent, the cap would be $708, and the installer would absorb the rest of the addition or ask for a different price. The 3 percent cap is an invented contract term used only to show how a cap interacts with the addition.

What to put in writing before you sign

• The module maker and model, and the countries where its cells and its finished modules are made, in the equipment list.
• Whether the modules and cells have already entered the country on the signing date, and the delivery date to the installer.
• Whether the price is fixed, and whether an escalation clause names tariffs, with its formula, its cap and its notice period.
• The module price per watt as its own line, not only inside the total.
• Which cost lines the installer says the floors affect (modules and cells) and which they do not (inverters, racking, labor).
• The expected ordering date for the equipment, so the quote can be set against the right end of the entered-value grid.