The United States Commerce Department said it will impose tariffs on solar panels imported from China after concluding that the Chinese government provided illegal export subsidies to manufacturers there. The tariffs were smaller than some American industry executives had hoped for, 2.9 percent to 4.73 percent, which could dull their effect on the market. Nonetheless, additional tariffs could be imposed in May, when the Commerce Department is scheduled to decide whether China is “dumping” solar