GS3 – Environment
Context:
A recent study, as reported in The Hindu, has introduced an environmentally friendly, water-based recycling method for perovskite solar cells (PSCs), offering a sustainable alternative to conventional toxic processes.
Understanding Perovskite Solar Cells (PSCs):
- Structure: Thin-film solar cells comprising a perovskite crystal layer sandwiched between conductive layers (typically metal electrodes and glass).
- Material Composition: Use metal-halide perovskites—primarily lead, iodide, and organic compounds.
- Advantages: Notable for their high energy conversion efficiency, cost-effectiveness, and versatile tunability in optical and electrical properties.
India’s Innovation – Carbon-Based PSCs (CPSCs):
- These are India’s first domestically developed PSCs, designed to improve durability and reduce manufacturing costs.
- Enhanced resistance to heat and moisture is achieved through compounds like Guanidinium iodide (GuI) and 5-aminovaleric acid iodide (5-AVAI).
- Offer high light absorption and efficient charge transport, making them ideal for Indian climatic conditions.
Challenges in PSC Technology:
- Durability: Compared to traditional silicon-based solar panels, PSCs tend to have a shorter operational lifespan.
- Environmental Risk: The presence of toxic lead raises serious concerns regarding safe disposal and recycling.
- Previous Recycling Practices: Relied on harmful organic solvents such as dimethylformamide (DMF), which posed additional environmental risks.
New Eco-Friendly Recycling Approach:
- Water-Based Process: Eliminates the need for toxic solvents, making the process safer and more sustainable.
- Key Chemicals Involved:
- Sodium acetate: Captures lead ions, forming water-soluble lead acetate.
- Sodium iodide and Hypophosphorous acid: Help regenerate high-purity perovskite crystals.
- Efficiency and Recovery:
- Achieves 99% material recovery, even after five recycling cycles.
- Maintains efficiency comparable to newly fabricated cells.
Environmental and Economic Significance:
- Supports Circular Economy: Facilitates reusability of materials, reducing solar waste and dependency on virgin raw materials.
- Reduced Emissions and Costs: The green method cuts down both environmental footprint and production costs, enhancing the affordability of solar energy.
- Alignment with National Goals:
- Promotes India’s vision of sustainable solar development.
- Helps mitigate solar panel waste and contributes to India’s renewable energy targets.
Relevance to India’s Solar Sector:
- Installed Solar Capacity: As of April 2025, India has achieved 105.65 GW of solar power, surpassing the 100 GW target set for 2030.
- Policy Support: Initiatives like PM-KUSUM and PM-KUSUM Urja Suraksha evam Utthaan Mahabhiyan aim to boost decentralized solar energy and reduce carbon dependence in the agriculture sector.