Matching Items (2)
Filtering by
- All Subjects: Silicon Solar Cells
- Creators: Augusto, Andre
Description
A major obstacle to sustainable solar technologies is end-of-life solar modules. In this thesis, a recycling process is proposed for crystalline-Si solar modules. It is a three-step process to break down Si modules and recover various materials. Over 95% of a module by weight can be recovered with this process. Two new technologies are demonstrated to enable the proposed recycling process. One is sequential electrowinning which allows multiple metals to be recovered one by one from Si modules, Ag, Pb, Sn and Cu. The other is sheet resistance monitoring by the 4-point probe which maximizes the amount of solar-grade Si recovered from Si modules with high throughput. The purity of the recovered metals is above 99% and the recovery rate can achieve between 70~80%. The recovered Si meets the specifications for solar-grade Si and at least 91% of Si from c-Si solar cells can be recovered. The recovered Si and metals are new feedstocks to the solar industry and generate over $12/module in revenue. This revenue enables a profitable recycling business for Si modules without any government support. The chemicals for recycling are carefully selected to minimize their environmental impact and also the cost. A network for collecting end-of-life solar modules is proposed based on the current distribution network for solar modules to contain the collection cost. As a result, the proposed recycling process for c-Si modules is technically, environmentally and financially sustainable.
ContributorsHuang, Wenxi (Author) / Tao, Meng (Thesis advisor) / Alford, Terry (Committee member) / Sinha, Parikhit (Committee member) / Arizona State University (Publisher)
Created2018
Description
In Professor Meng Tao and Wen-His Huang's paper's [1,2] the recycling process to create a sustainable Photovoltaic (PV) industry is laid out. The process utilized to recycle the materials requires the use of three semi-problematic chemicals including: Sodium Hydroxide (NaOH), Nitric Acid (HNO3), and Hydrofluoric Acid (HF). By utilizing a combination of reverse osmosis filtration, pre-lime treatment, neutralization by combination, and mineral specific filtering the chemicals can either by recycled as Environmental Protection Agency (EPA) standardized waste water or profitable byproducts such as Sodium Nitrate (NaNO3). For the recycling of hydrofluoric acid, a combination of pre-lime coagulation, microfiltration and a spiral wound reverse osmosis (RO) system, less than 1mg/L in line with national standards for human consumption. The sodium hydroxide and nitric acid recycling process handles more contaminants that just the byproduct of the chemicals and manages this through a combination of multi-stage flash/vapor distillation along with a reverse osmosis filtration system. By utilizing both systems of recycling, a completely closed loop system for recycling silicon solar cells is laid out and creates a new standard for clean energy management.
ContributorsHaft, Brock Todd (Author) / Tao, Meng (Thesis director) / Augusto, Andre (Committee member) / Barrett, The Honors College (Contributor)
Created2016-12