Wiley Rein warns that importing ‘blue wafers’ for solar cell production could create compliance risks for US developers and manufacturers
Under US Department of Commerce rules, the country where the P/N junction is formed determines the origin of a solar cell for trade duties
If blue wafers come from countries under AD/CVD, duties may apply even if cells or modules are finished elsewhere
The issue could also affect eligibility for incentives such as the Section 45X Advanced Manufacturing Production Tax Credit
Solar developers and manufacturers in the US could face growing compliance risks linked to the use of imported ‘blue wafers’ in solar cell production, according to an analysis by Wiley Rein LLP. The firm says conflicting interpretations by the US Customs and Border Protection (CBP) on solar cell origin could expose projects to trade duties and threaten eligibility for US clean-energy tax credits.
According to a legal alert issued by Wiley, some manufacturers in the US are importing blue wafers that already have the P/N junction, then performing minor processing on the cells and assembling them into modules to claim US origin.
This practice raises material questions under US trade law and tax credit programs, thereby exposing importers to significant compliance risk, it argues. That’s because the blue wafers may have been imported from countries subject to the US’ antidumping and countervailing duties (AD/CVD).
A blue wafer is a silicon wafer that already has a P/N junction formed – a process that enables it to convert sunlight into electricity. Soon after the formation of the P/N junction, an anti-reflective coating is applied, giving it the characteristic blue color. Before the P/N junction is applied, it is a ‘gray wafer’ that cannot generate electricity.
Updated guidance from the Internal Revenue Service (IRS) in Notice 2025-8, according to Wiley, defines a solar PV wafer as a thin slice of crystalline silicon produced by forming and slicing an ingot from molten polysilicon. This definition aligns with what the industry calls a gray wafer and excludes the doping step that forms a P/N junction.
As a result, once a wafer undergoes that processing and becomes a blue wafer, the guidance implies it may already be considered an unfinished PV cell rather than a subcomponent.
Some may argue that blue wafers are still different from finished cells, stresses Wiley. However, since blue wafers can already convert sunlight into electricity, like finished cells, this argument is weak. It points out that because the Domestic Content Adder (DCA) policy is meant to boost solar manufacturing and investment in the US, the US Department of the Treasury and the IRS are unlikely to support treating blue wafers as simple subcomponents. It could allow manufacturers to claim tax credits without making real manufacturing investments in the US.
Moreover, the US Department of Commerce says the country where the P/N junction is created determines the origin of a solar cell for anti-dumping and countervailing duty (AD/CVD) rules. A solar cell is defined as a product that already has a P/N junction, even if other steps like adding gridlines or busbars are done later.
Because of this rule, solar cells made in countries such as China, Taiwan, Cambodia, Thailand, Vietnam, and Malaysia, as well as modules containing those cells, are subject to AD/CVD duties. Wiley Rein Partner Timothy C. Brightbill, one of the authors of the analysis, points out that similar duties may also apply in the future to cells from India, Laos, and Indonesia due to ongoing investigations (see India, Indonesia, Laos Solar Imports Face High US CVD Rates).
If blue wafers with P/N junctions come from a country subject to AD/CVD orders, duties will apply, even if the cells or modules are finished in another country using those wafers. If importers do not pay these duties, the CBP will require payment and impose heavy penalties.
This could affect eligibility for incentives such as the Section 45X Advanced Manufacturing Production Tax Credit and domestic content benefits, particularly if solar cells are finished in the US using imported blue wafers. Since manufacturers claim tax credits for producing solar cells in the US, if they interpret the rules conveniently, it will be the developers who could face risks. Hence, the analysis suggests developers must verify manufacturer claims.
“The use of imported blue wafers to create photovoltaic cells in the U.S. puts at risk any claim that the cells are “produced in the United States.” Guidance from Treasury and the IRS suggests that all manufacturing processes of a manufactured product component must take place in the U.S. in order for the component to be deemed produced in the U.S.,” reads the analysis from Wiley that represents the Alliance for American Solar Manufacturing and Trade (AASMTC) in solar AD/CVD cases (see USITC Issues Final Injury Determination In AD/CVD Investigation).
Speaking of blue wafers, back in 2019, the Ministry of New and Renewable Energy (MNRE) in India clarified that it wouldn’t allow the use of imported blue wafers for PV cells to be used for its programs, where domestically manufactured solar cells and modules are required. Instead, it directed the use of undiffused silicon wafer or black wafer to establish a strong solar manufacturing base in the country (see No Imported Blue Wafer Cells For DCR PV Projects In India).