U.S. solar developers are bracing for months of uncertainty after a federal trade agency ruled that imported panels are crippling American manufacturers, giving President Trump until January to decide whether to impose tariffs.

The $29 billion industry had largely expected the 4-0 decision Friday from the U.S. International Trade Commission. Even before the vote, developers were halting construction and hoarding supplies, anticipating that tariffs could sharply increase prices for imported components.

Now, solar companies are left waiting as the commission prepares to send recommendations on how to protect U.S. manufacturers to Trump. The president has until Jan. 12 to decide the size, scope, and duration of any tariffs. Until it's clear how they will affect panel prices, developers will be in the dark when it comes to planning projects.

Most of the U.S. solar industry opposes tariffs, arguing that inexpensive foreign panels have driven a boom in clean energy projects and created tens of thousands of jobs. In the end, the impact of tariffs will hinge on how much they increase panel prices.