Cheap imports have fueled the U.S. solar industry’s dramatic growth for years. Now, mounting trade and transport issues are exposing that dependence to slowing shipments and putting big projects at risk, according to industry representatives. Tighter availability of foreign panels could hurt the booming industry and set back President Joe Biden’s effort to decarbonize the nation’s power sector, a centerpiece of his plan to combat climate change. Some 90 percent of U.S. solar panels are made overseas, according to the U.S. Energy Information Administration. Among the issues clouding solar’s outlook is an attempt by U.S. authorities to block shipments of panels containing components potentially derived from forced labor in China’s Xinjiang region. The Biden administration imposed an import ban targeting China’s Hoshine Silicon Industry Co. in June and since then, hundreds of megawatts of panels have been detained at the border, according to an industry source. U.S. Customs and Border …