The U.S. Commerce Department has just launched an investigation into alleged dumping claims against wind energy towers from China and Vietnam. If the investigation shows injury to U.S. businesses, the result could be serious import duties on more than $100 million worth of imported wind energy towers. There is already friction between the U.S. and China on clean energy-related trade – last month the U.S. International Trade Commission stated that there is “a reasonable indication” that Chinese imports of crystalline silicon solar panels were hurting American companies because of unfair Chinese government subsidies. A Department of Commerce investigation is now expected to trigger up to a 10% customs tariff by the end of 2012 on importers of Chinese silicon solar panels.