Book

Description

One of the major actual challenges of humankind is to mitigate the effects of climate change. Based on the CO₂-equivalent emission, the energy transition from a fossil fuel-based to a renewable energy source is one of the key objectives. The photovoltaics silicon supply chain has reached the level of more than 1 GWp installed per day in 2023. The prospect is very positive, with the 1TWp yearly installations already being reached before all predictions in 2026 as an optimistic scenario. The production process to obtain a silicon based solar module starts from mining quartz from nature and obtaining receiving the pure silicon via several metallurgical and chemical steps, from carbothermic reduction in submerged arc furnaces down to production of ultra-pure polysilicon for photovoltaics and semiconductor grades in well-known chemical processes such as fluid bed Reactors, (CVD) Chemical Vapor Deposition SIEMENS reactors and distillation steps. The downstream production via pulling monocrystalline solar-grade silicon ingots via the Czochralski method followed by wafering steps, that are precursors of Cells and Module manufacturing, also generate by products and consumes energy which impact the final CO₂ equivalent emissions to obtain the Solar Module as final product. The Silicon 5.0 ® concept focus on reduce this CO₂ footprint alongside the entire photovoltaics supply chain. The 3 pillars for the Silicon 5.0 ® are wastes reduction via Recycling methods, Integration benefits for the whole Supply Chain and highest Automation and digitalization level for the integrated plant. The integration benefits along the supply chain could be measured within these 3 major pillars. The usage of automated steps on tapping, stocking and furnace control system for submerged arc furnaces on obtaining step of Silicon at 99% grade are part of the automation pillar. The automation charge and discharge of the Siemens reactors together with the wafering process are also contributing to leverage the Silicon 5.0 ® concept.