A World-First in Sustainable Solar Panel Recycling
Shibaura Institute of Technology (SIT) and K・F・C Co., Ltd. have successfully achieved a global first: the purification, recovery, and recycling of the rare metal selenium ($\text{Se}$) from discarded photovoltaic (PV) modules using a biological process. This groundbreaking technology addresses the growing environmental challenge posed by the impending mass disposal of solar panels. The global solar panel recycling market is projected to reach between $477 million and $1.7 billion by 2030, driven by the necessity of managing end-of-life PV waste.
The Power of the Microbe: Stutzerimonas stutzeri NT-I
The core of this innovation lies in the use of the selenate-reducing microorganism, Stutzerimonas stutzeriNT-I. The process specifically targets CIGS (Copper-Indium-Gallium-Selenium) thin-film solar panels, which contain a substantial amount of selenium. Initially, the CIGS material is dissolved from the end-of-life panels. Following a neutralization step, the solution is reacted with the S. stutzeri NT-I microbes. These organisms efficiently reduce the toxic selenate and selenite compounds, allowing for the effective precipitation and recovery of elemental selenium. The thin-film segment of the recycling market, which includes CIGS, is expected to see a particularly high growth rate, with some forecasts suggesting an 18.2% CAGR through 2030.
Addressing Environmental and Market Needs
Selenium is a critical rare metal used in semiconductor materials and the CIGS PV industry. While essential, its compounds, such as selenate and selenite, are toxic, requiring strict environmental standards. As the solar panel market is projected to face a surge in disposal volumes post-2030, this technology offers a vital, environmentally friendly solution. This metal biotechnology approach not only secures the supply of a valuable rare metal but also crucially prevents the environmental pollution caused by hazardous substances in defunct solar panels, contributing directly to the realization of a robust circular economy.
