America’s solar module factories have expanded to more than 65 gigawatts of nameplate capacity, well above the country’s 2025 annual installation total, but the industry’s latest data reveal a critical gap one step upstream: the United States currently has just 3 gigawatts of solar cell manufacturing capacity. New cell factories now in development are not expected to be enough to supply all domestic module facilities.
Module boom, cell bottleneck
In 2025, cell production capacity continued to grow and module manufacturing increased more than 50%, with 65.5 GW of capacity online. Yet actual production at those facilities remains considerably below nameplate capacity, and the cell supply chain has not kept pace.
The figures come from the SEIA and Wood Mackenzie Q2 2026 report, published in mid-July, along with the 2025 Year in Review report released in March 2026.
Trade actions and tariffs continue to challenge portions of the U.S. solar manufacturing industry. In practical terms, American factories can assemble finished panels at scale, but they remain dependent on foreign suppliers for the semiconductor wafers and cells that go inside them.
Module assembly has expanded faster than upstream segments such as solar cells, wafers, and key materials. That lopsided growth is now the defining challenge for an industry trying to build a self-sufficient domestic supply chain.
Those module assembly expansions, including plans by multiple companies to add gigawatts of panel capacity across Texas and other states, rest on a foundation of imported cells that new tariffs are making more expensive.
New tariffs reach India, Indonesia and Laos
The cell shortage is being sharpened by an expanding ring of trade actions. In the spring, the Department of Commerce announced high preliminary countervailing and anti-dumping tariff rates for solar cells and modules from India, Indonesia, and Laos, countries that had become major alternative suppliers after earlier duties cut off imports from Cambodia, Malaysia, Thailand, and Vietnam.
Module imports from those four original countries plummeted from an average of 3.8 gigawatts per month in 2024 to an average of 1.1 gigawatts per month in the first quarter of 2025. Cambodia dropped to zero after its producers refused to cooperate with the antidumping investigation and received the highest duty rates.
The U.S. International Trade Commission made an affirmative final determination that the U.S. solar industry was harmed by imports from Cambodia, Malaysia, Thailand, and Vietnam. That ruling cleared the way for U.S. Customs and Border Protection to begin collecting the new duties.
Tariffs on imports from Cambodia range from 650 percent to 3,500 percent. Malaysian tariffs range from 14 percent to 250 percent, Thai tariffs range from 375 percent to 972 percent, and Vietnamese tariffs range from 120 percent to 813 percent.
Cost pressure climbs the supply chain
Despite module prices falling to $0.34 per watt in the first quarter of 2026 compared with $0.43 per watt a year earlier, commercial system prices increased 4 percent year-over-year to $1.67 per watt. Equipment costs for both electrical and structural balance-of-system increased 60 percent year-on-year for the commercial segment, with Section 232 metal tariffs driving up costs for both imported and domestic equipment.
The pressure is prompting manufacturers to accelerate upstream investment. Corning started ingot and wafer production at its Michigan plant during the third quarter of 2025.
ES Foundry celebrated the grand opening of its Greenwood, South Carolina manufacturing facility on January 31, 2025. The company has since completed a 2 GW expansion of that facility, bringing total annual production capacity to 3 GW. Prior to ES Foundry’s launch, domestic solar cell production was limited; other crystalline silicon cell manufacturers operating in the United States include Suniva, which has a 1 GW factory in South Carolina, and Qcells, which manufactures cells at its Cartersville, Georgia plant. Those additions, while significant, still leave the country far short of the cell output needed to feed its growing fleet of module assembly lines.
What it means for U.S. solar supply
Crystalline silicon cell manufacturing stands at just 3 GW, and while industry projections aim to reach 20.5 GW of cell capacity by 2027, the transition from equipment order to commercial output takes 18 to 24 months. A broad new trade action could severely constrain manufacturing activity for some domestic producers.
The U.S. solar industry installed 43 gigawatts of new capacity in 2025, remaining the dominant source of new capacity added to the grid for the fifth consecutive year.
Sustaining that pace while closing the cell-manufacturing gap will require investment not just in final assembly but in the more capital-intensive upstream steps, including ingots, wafers, and cells, that determine whether the domestic industry can eventually stand on its own.
For grid planners counting on continued solar growth to meet rising electricity demand, the record battery storage buildout planned for 2026 depends on that same supply chain delivering panels reliably and affordably.
