The US government has imposed tariffs of around 30 percent on solar panels imported from China, sparking charges of “trade protectionism” from Chinese government officials and increasing friction between the two countries.

The US Commerce Department ruled yesterday in favor of American companies that charged Chinese exporters had illegally “dumped” their solar panels on the US market below fair market price.

Commerce officials will continue their investigations in the trade cases, and are scheduled to release final determinations in July, although that decision will likely be postponed until late September. The International Trade Commission will issue its final determination on whether the US solar manufacturing industry was harmed by Chinese trade practices later this fall.