The kingdom is trying to juggle its still-vital petroleum industry with alternative energy sources like wind and solar as it faces pressure to lower carbon emissions.
Officials said the decision would lower bills and encourage people to use cars and appliances that did not use fossil fuels, but some experts said it would discourage energy efficiency.
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.