Key Solar Panel Ingredient Is Made in the U.S.A. Again NYT: Technology By: Ivan Penn 25 April 2024 at 13:57 REC Silicon says it will soon start shipping polysilicon, which has come mostly from China, reviving a Washington State factory that shut down in 2019. ยฉ Ruth Fremson/The New York TimesREC Silicon is preparing to fulfill its first shipment of polysilicon granules, which are used in the production of solar panels, at its factory in Moses Lake, Wash.