By Doug Young GCL Technology Holdings Ltd. (OTC: GCPEF) said on Friday its revenue fell slightly last year and its profit plunged, as booming demand for new solar power plants was offset by plunging prices for the polysilicon that is the company’s main product. GCL said its revenue fell 6.2% for the year to 33.7 billion yuan ($4.68 billion), while its profit tumbled by 85% to 2.5 billion yuan. Calculations using company data show its revenue fell to 12.8 billion yuan in the second half of the year, down 39% from the first half. As its revenue tumbled, the company lost 3 billion yuan in the sec…