Over the past decade, the U.S. has imposed a range of tariffs on imported solar panels to protect domestic manufacturers and respond to foreign trade practices. From anti-dumping duties targeting Chinese imports to broad safeguard tariffs affecting nearly all foreign suppliers, these policies have evolved under multiple administrations. Meanwhile, global solar panel prices have declined sharply, reducing the impact of these tariffs on overall project economics. This article provides a chronological, detailed overview of solar tariffs in the U.S., the rationale behind them, their implementation, and how they have affected the solar industry—particularly in terms of cost, supply chain behavior, and investment dynamics.

The first significant solar tariffs came in response to a 2011 trade petition led by SolarWorld (the U.S. subsidiary of a German company), which alleged that Chinese manufacturers were flooding the U.S. market with underpriced solar panels due to heavy state subsidies. The U.S. Department of Commerce found in favor of SolarWorld and imposed anti-dumping and countervailing duties in 2012, averaging around 31% on Chinese solar cells and modules. Chinese manufacturers responded by shifting production to other countries, particularly Taiwan. In 2014, the U.S. expanded its tariffs to include Taiwanese producers, with rates reaching 50% for some companies. This marked the first phase of ongoing trade maneuvering, with foreign companies seeking to avoid tariffs through geographic shifts in manufacturing.

By 2017, U.S. manufacturers SolarWorld and Suniva (both in financial distress) filed a petition under Section 201 of the Trade Act, which allows for global safeguard measures without proof of dumping. They argued that a surge of low-cost imports was harming the domestic industry across the board. In January 2018, the Trump administration enacted a 30% tariff on nearly all imported crystalline silicon solar modules and cells, regardless of country of origin. The tariff was set to decline by 5% annually, down to 15% by 2021.

This global tariff represented a major policy shift, expanding beyond targeted duties on specific countries to broad-based trade protection. Despite the intent, the tariffs did not revive the original petitioning companies. Suniva and SolarWorld both continued to struggle, and the tariffs raised costs for U.S. developers by an estimated $0.10–$0.15 per watt at the time—about a 10% increase in utility-scale system costs.

The announcement of tariffs led to a surge in panel imports before implementation. Developers and installers rushed to buy and warehouse panels to lock in lower costs—a strategy informally called “safe harboring.” In Q4 2017, panel imports surged dramatically, softening the immediate impact of the tariffs but creating a short-term boom-bust cycle.

This practice disproportionately benefited large, well-capitalized firms that could afford to buy in bulk. Smaller developers without the financial flexibility faced higher costs once tariffs took effect. The episode highlighted how sudden policy shifts can distort solar procurement and favor industry incumbents.

In February 2022, the Biden administration extended the Section 201 tariffs for another four years but doubled the import quota for tariff-free solar cells (from 2.5 GW to 5 GW annually) and maintained a tariff exemption for bifacial modules, which had become standard in utility-scale projects.

However, in 2022, a new front opened when Auxin Solar, a small U.S. manufacturer, petitioned the Commerce Department to investigate whether Chinese firms were evading tariffs by assembling panels in Southeast Asia. In 2023, the Department concluded that multiple firms in Vietnam, Thailand, and Cambodia—subsidiaries of Chinese companies—were indeed circumventing duties. These firms were made subject to the original anti-dumping and countervailing duties (some exceeding 50%).

To avoid immediate market disruption, the administration delayed enforcement until mid-2024. Meanwhile, in 2024, the Biden administration also removed the bifacial exemption, applying the 15% safeguard tariff to all imported modules.

By 2025, the current tariff regime includes a 15% safeguard duty on all crystalline silicon modules, including bifacial, and potential anti-circumvention tariffs on certain Southeast Asian manufacturers. Direct Chinese imports face layered duties under multiple trade authorities—including Section 301 tariffs, which rose from 25% to 50% in 2024 for solar cells.

Despite these measures, developers have adapted. The solar market has diversified its supply chains, sourced from exempted manufacturers, and relied on federal tax credits to offset cost increases. The Inflation Reduction Act has introduced additional production incentives to encourage domestic manufacturing, and several companies (including Hanwha Qcells and Meyer Burger) have announced U.S. factory investments.

Despite the support provided by both tariffs and the Inflation Reduction Act, the cost of domestically produced panels remains higher than imported alternatives. That said, the price gap has narrowed. In 2024, U.S.-made panels typically cost $0.30–$0.50 per watt, while post-tariff imports ranged from $0.15–$0.25 per watt, depending on source country and applicable duties. With more domestic production coming online and global tariffs remaining in place, some domestically produced panels are approaching price parity—a marked shift from previous years.