Plans to install 60 square kilometers of solar panels in Vermont are suddenly on hold.
In Maine, a solar farm that would power hundreds of homes is partly built but might not be completed.
And a project in Texas that would have powered more than 10,000 homes was weeks away from breaking ground but has now been postponed until at least next year.
Around the country, solar companies are delaying projects, scrambling for supplies, shutting down construction sites and warning that tens of billions of dollars — and tens of thousands of jobs — are at risk.
The tumult is the result of a decision by the Commerce Department to investigate whether Chinese companies are circumventing U.S. tariffs by moving components for solar panels through four Southeast Asian countries.
Though officials have not yet found any evidence of trade violations, the threat of retroactive tariffs has effectively stopped imports of crystalline silicon panels and components from Cambodia, Malaysia, Thailand, and Vietnam. These four countries provide 82 percent of the most popular type of solar modules used in the U.S.
In a matter of weeks, 318 solar projects in the U.S. have been canceled or delayed, and hundreds of companies are considering layoffs, according to the Solar Energy Industries Association, which surveyed more than 700 companies in recent days.
Energy experts warn that the fallout is only beginning. A monthslong halt on imports from the four countries could have lasting ramifications for the multibillion-dollar solar industry and for the Biden administration’s ambitious goals to ramp up renewable energy development to combat climate change.
“The industry is essentially frozen,” said Leah Stokes, a political scientist who studies climate at the University of California, Santa Barbara. “It’s already leading to layoffs, to say nothing of the impact on our climate goals.”
The Commerce Department initiated its investigation on March 25 after Auxin Solar, a small solar panel manufacturer based in California, filed a petition requesting an inquiry into whether China was circumventing rules intended to prevent state-subsidized solar parts from flooding the U.S. market.
Tariffs on Chinese solar panels have been in place since 2012, when the Obama administration imposed them in hopes of promoting domestic manufacturing and preventing China from dominating the emerging global market. In 2018, President Donald J. Trump imposed additional tariffs on certain solar products from China, and Mr. Biden extended those tariffs in February.
For more than a decade, China has dominated the global supply chain for solar panels. The government’s policies and subsidies have nurtured giant factories churning out materials like polysilicon and components like solar cells that absorb energy from sunlight and convert it into electricity.
To avoid trade problems, U.S. solar installers have bought many of their panels from the four Southeast Asian countries. But according to Auxin, many of those panels are manufactured by overseas subsidiaries of Chinese companies and use cells, wafers and other parts that originated in China.
Until now, the Commerce Department had signaled that because the parts coming from China were substantially transformed by the …….