US trade officials finalized steep tariff levels on most solar cells from Southeast Asia, a key step toward wrapping up a year-old trade case in which American manufacturers accused Chinese companies of flooding the market with unfairly cheap goods.

The US Commerce Department has announced plans to impose tariffs of up to 3,521% on imports of solar panels from four South East Asian countries. It comes after an investigation that began a year ago when several major solar equipment producers asked the administration of then-President Joe Biden to protect their US operations.

The United States has just made a huge decision that could shake up the solar power industry. The U.S. government has decided to put very high tariffs — basically extra taxes — on solar panels and equipment coming from four countries in Southeast Asia: Cambodia,