What are the environmental impacts of producing perovskite solar cells

The production of perovskite solar cells (PSCs) presents both environmental advantages and challenges, particularly related to material toxicity, manufacturing impacts, and end-of-life disposal.

Environmental Advantages of Perovskite Solar Cells Production

• Lower Carbon Footprint and Energy Use
  Perovskite solar cells generally have a lower carbon footprint and require significantly less energy to manufacture compared to traditional silicon solar panels. This is primarily because PSCs can be made using low-temperature processes like screen-printing, which are less energy-intensive than the high-temperature purification needed for silicon. For example, perovskite-perovskite tandem cells require about 78% less energy to produce than perovskite-silicon tandems, and PSCs can have an energy payback period as short as four months compared to over a year for silicon cells. This means PSCs can generate the amount of energy used in their production much faster, contributing positively to sustainable energy deployment.
• Potential for Reduced Environmental Impact Over Lifetime
  Life-cycle analyses show that perovskite-on-silicon tandem modules can have 6% to 18% lower environmental impact than silicon-only modules when accounting for the greater energy generated over their lifetime. Although tandem modules might have somewhat higher impacts in some categories (like global warming potential and resource depletion) during manufacturing, these are offset by their increased efficiency and energy generation over time.

Environmental Challenges and Risks

• Lead Toxicity and Environmental Contamination
  A key environmental concern with PSCs is the use of lead in their perovskite materials. Most high-performance PSCs contain lead compounds, commonly lead iodide, which is water-soluble and can leach into the environment if modules degrade or break. Lead is highly toxic to humans and ecosystems, impacting neurological health and causing environmental contamination risks, especially if lead ions leak into soil or water. The lead content in PSCs can increase local soil lead concentrations significantly upon release. This toxicity risk is compounded by PSCs’ susceptibility to environmental degradation due to moisture, heat, and mechanical stress, which can accelerate lead release.
• Need for Improved Stability and Encapsulation
  PSCs are less stable than silicon panels and vulnerable to degradation by air, moisture, and heat. This instability raises concerns about premature failure and release of hazardous materials. Advanced encapsulation and interfacial engineering are critical to protect PSCs from environmental damage and extend their operational life, reducing environmental risk over time.
• End-of-Life Management
  Disposal and recycling of PSCs pose challenges due to the hazardous nature of lead and other materials. Without proper recycling, modules may release toxic lead compounds. There is a gap in standardized testing and regulations for safe disposal and recycling of PSC modules. Developing recycling programs and recovery methods for valuable materials like lead and silver is essential to mitigate environmental impacts and enable a circular economy for PSCs.
• Comparisons with Lead-Free Alternatives
  Lead-free perovskite materials are being explored but often come with trade-offs, such as lower efficiencies or other environmental impacts. Proper encapsulation and recycling currently make lead-containing PSCs preferable in terms of sustainability despite toxicity concerns. However, more research is needed on alternatives’ material abundance, toxicity, and environmental impact.

Summary Table of Key Environmental Aspects

In conclusion, the environmental impacts of producing perovskite solar cells are mixed: they offer clear sustainability advantages over traditional silicon panels due to lower energy use and carbon emissions in manufacturing, but their use of toxic lead and relative instability pose environmental risks that require careful management through improved materials, encapsulation, and recycling strategies.