NEERI eyeing recovery of valuable materials from solar panels

 

 

 

With increase in usage and installation of photo voltaic (PV) solar panels and the Government promoting solar energy, a new set of problems has arisen. For, this increase is projected to lead to a huge increase in generation of PV solar panel waste, whose disposal involves various aspects. Against this backdrop, CSIR-National Environmental Engineering Research Institute (NEERI) has moved a proposal for recovery of valuable materials from the PV solar panels and also has proposed a protocol for scientific disposal of hazardous materials in these panels. Three top scientists of NEERI including Dr Atul Vaidya, Director of NEERI; Dr Sushant Wath, Principal Scientist; and Mahendra Patil, Chief Scientist, had first flagged the challenges regarding disposal of PV solar panels in their paper published in the Journal of Metallurgy and Materials Science last year.

 

Titled ‘India’s Solar Mission: Current Scenario and Challenges Ahead -- An Overview’, the paper pointed out that the increase in usage and installation had brought the ‘associated problem’ of generation of huge quantum of PV solar panel waste and more importantly its safe disposal. The major problem being the presence of various hazardous materials in PV panels. As per the experts, the average life-span of a PV solar panel ranges from 20-25 years. So, a huge quantum of end-of-life (EOL) PV solar panels is generated once their life-span is over. Besides, some get discarded earlier than that. Some also turn into waste due to natural calamity. In solar cells and other parts, several pollutants are found. These include Arsenic, Chromium, Lead, and Cadmium in batteries, Mercury, Brominated Fire Retardants etc. These hazardous materials in discarded panels have severe environmental and health implications, if they are not handled and processed systematically and scientifically. This particular type of waste may “add up to already stressed existing waste management systems including municipal solid waste and hazardous industrial waste,” observed the scientists in their paper. Further, they had pointed out that the processing of EOL PV panels mostly included mechanical, thermal, and chemical treatment in highly corrosive reagents including hydrochloric acid, sulphuric acid etc and hence it had certain limitations. One of the limitations is enviromental concerns due to toxic emissions, high process waste in the form of sludge and wastewater.

 

Another limitation is regarding process economy, as such treatments are expensive and less efficient in terms of yield recovery and purity. Dr Sushant Wath told ‘The Hitavada’ that the waste PV solar panels contained hazardous as well as valuble materials. They could be a rich source of valuable materials such as aluminum, plastic, silicon, silver copper, and other rare earth materials such as indium, gallium, germanium etc. In view of shortage of requisite raw materials needed for development and production of PV solar panel within India, recovery of silver, silicon and other materials could be good option. “We are working on recovery of valuable materials like copper, silicon, silver etc. Hazardous materials can’t be disposed of casually, they need scientific methods to avoid environmental pollution. there is need for delineating scientific processing interventions. Hence, we have also proposed protocol outline for scientific diposal of hazardous materials in PV solar panels,” he said.

 

The proposals of NEERI have been sent to Council of Scientific and Industrial Research (CSIR) headquarters under Waste-to-Wealth Mission. “CSIR headquarters and expert committee are reviewing our proposals for funding. In fact, a review meeting was held a couple of days ago. Based on their recommendation, we will come to know about status of our project proposal,” said Dr Wath. Asked about reuse of the discarded solar panels, Dr Wath observed that it could at best prolong the final disposal but would not offer solution. Since the publication of the paper authored by Dr Vaidya, Dr Wath, and Patil, the Central Government has categorised solar panels as e-waste under E-Waste Rules of 2022. This is a good beginning and pave the way for further measures.