Low cost, low CO2 emission solar grade silicon

Grade Silicon (SGS) manufactured by upgrading Metallurgical Grade Silicon (MGSi) holds the promise of low manufacturing cost as necessary to achieve grid parity using crystalline silicon technology. In this paper, tje authors discuss the results of a Cost of Ownership (CoO) evaluation of a proprietary SGS manufacturing process, assigned by MB Scientific to One Solar Energy (OSE Process), a new venture in SGS manufacturing. The OSE Process, from quartz to SGS, is based on a new single-electrode arc furnace, used to produce high quality MGSi, coupled to a refining system to reduce B and P down to the required SGS levels. In particular, the authors compare the specific energy consumption (SEC) and CO2 emissions (COE) for various technologies used in manufacturing this Upgraded Metallurgical Silicon (UMG) SGS. The SEC differences between our SGS process and the current state-of-the-art, ultra high purity polysilicon process, are due to improved thermal efficiency and Si recovery of our arc furnace over conventional 3phase submerged arc silicon furnaces. The overall low cost and cleanliness of our "green" process is due to the superior SEC, high recovery of silicon, low emissions, and recycling of CO gas for power generation.