Polysilicon used in solar panels is set to extend its rebound from a decade low as China moves to impose duties on importers such as Germany's Wacker Chemie AG. Spot prices will jump as much as 39 percent this year to $22 a kilogram ($9.98 a pound), according to the median estimate in a Bloomberg survey of seven analysts. The commodity hit a low $15.83 in December, the cheapest price since at least 2000, according to data compiled by Bloomberg.