This year's biggest winners in the solar sector don't make panels

Producers of raw materials for the solar sector are the key beneficiaries of rising demand this year, outpacing profit growth posted by the largest panel manufacturers. 

Tongwei Co., the top global producer of polysilicon, a key solar material, saw earnings more than triple in the first nine months to 21.7 billion yuan ($3 billion) as prices soared, according to filings. Net profit for rival Xinjiang Daqo New Energy Co. surged 237% in the year through September.

Polysilicon prices surged to the highest level since 2011 earlier this year amid plant outages, shipping snarls and strong demand fueled by China’s world-leading