The methods of purification of "Kazsilicon" metallurgical silicon produced by the carbothermal method, i.e., the reduction of high purity Sary Kol quartz into carbon, are developed. These technologies provide the basis for the industrial production of silicon, solar cells, panels, and solar power plants. Using these technologies, solar grade silicon is produced, on the basis of which solar cells with an efficiency of 15.8-17.1% are fabricated. Panels of solar cells compose the "Astana Solar", i.e., the first solar power plant in Kazakhstan with a power of 250 kW, which was put into operation December 25, 2012.