China was mustering government investments that dwarfed the U.S. effort and coupling them with national mandates that forced utilities to use renewable power. The country now makes most of the worlds polysilicon, a key material in solar panels. It also kept its labor costs lower than those in most industrial countries and has been willing to prop up unprofitable operations.
But half the world s supply of polysilicon now comes from China s Xinjiang region, where an estimated 1 million ethnic minorities, including Muslim Uyghurs,…