Sola Clean Blog

Why Clean Your Solar Panels Regularly?

Posted on 2024-06-01 by Will Jones

With all the rain the past few years, keeping your solar panels clean in the Murwillumbah and the Tweed Region has been a challenge. However, keeping your panels clean is essential for maximizing energy efficiency and protecting your investment. Dust, bird droppings, and debris can reduce output by up to 30%. Regular cleaning ensures your panels operate at peak performance and helps maintain your warranty.

For best results, use deionised water and a soft brush, or contact a professional service like Sola Clean!

Unlocking Value from End-of-Life Solar Panels: Pathways to High-Value Silicon Recovery and Resource Circularity

Posted on 2025-07-18 by Will Jones

Introduction

The global growth of solar photovoltaic (PV) technology, driven by the shift toward sustainable energy, is generating a major challenge: the rapid accumulation of end-of-life (EOL) solar modules. Although solar panels are typically designed to last 25–30 years, many are decommissioned earlier. By 2050, global PV waste could reach 80 million tonnes (Lee et al., 2024). In Australia, with its high solar adoption rate, cumulative waste is projected to reach 1 million tonnes by 2035 (Deng et al., 2024).

A major concern is that most EOL modules currently end up in landfill due to a lack of cost-effective recycling methods for high-purity materials. Landfilling poses environmental risks from hazardous substances like lead and cadmium and leads to the loss of valuable resources. Solar panels contain materials such as glass, aluminium, copper, silver, and, importantly, high-purity silicon.

Research shows that up to 90% of photovoltaic panels are landfilled as hazardous waste in Australia (CSIRO, 2024). Producing these materials originally requires energy-intensive processes, contributing significantly to lifecycle emissions.

Recognising this, the CSIRO has proposed the Australian Silicon Action Plan, outlining the economic potential of developing an integrated silicon and solar cell supply chain to enable a circular economy (CSIRO, 2025). Recovering and reusing materials—especially high-purity silicon and silver—is therefore essential for reducing waste, conserving resources, and lowering the embodied carbon of new materials. EOL solar panels should be seen not as waste, but as a resource.

Objectives

• Emphasise that EOL PV panels are a valuable resource containing recoverable materials, particularly silicon.
• Present examples of technologies capable of recovering high-purity silicon.
• Highlight potential high-value applications of recovered silicon, such as in new solar cells and battery anodes.
• Demonstrate how silicon recovery can reduce landfill reliance, lower emissions, and conserve critical materials.

Methods

This overview is based on a literature review of academic sources and technical reports. The review included the composition of PV modules, projected waste volumes, recycling technologies—especially silicon recovery—and reuse pathways such as electrochemical and chemical methods.

Results

Each tonne of module waste contains valuable components, including about 30 kg of high-purity silicon (Lee et al., 2024). However, silicon and silver are often not recycled or recovered only for low-grade uses, such as in cement (Owen & Xiaotu, 2024), resulting in value loss.

An innovative alkaline leaching process using sodium hydroxide (NaOH) and hydrochloric acid (HCl) has been developed to extract silicon. This yields high-purity silica (SiO₂) at 99.994% purity and a silicon recovery rate of 92.74% (Owen & Xiaotu, 2024).

Electrochemical techniques like high-temperature molten salt electrorefining can upgrade recovered silicon to 99.999% purity. These methods require only 9.3 kWh/kg, significantly less than the Siemens process used for new silicon production (Lee et al., 2024).

Solutions

1. Reuse in Solar Cells

Recovered silicon has been used to manufacture new PERC solar cells, achieving 19.7% efficiency, confirming its technical feasibility (Fraunhofer Institute, 2022).

2. Reuse in Batteries

Nanoscale silicon from EOL solar panels shows promise for use in lithium-ion battery anodes. It offers a theoretical capacity of approximately 4,200 mAh/g—far superior to graphite’s 372 mAh/g (Naseer et al., 2025). EOL panels could thus supply battery-grade silicon.

Discussion

End-of-life solar panels are a valuable resource. Current low-value recycling or landfilling leads to environmental harm and the loss of high-purity materials. Recovery methods such as alkaline leaching and electrorefining offer more sustainable alternatives and have demonstrated success in solar and battery applications.

Challenges

• Economic Viability: High-purity recovery is costly compared to landfill. Markets for recycled materials must be developed.
• Logistics: Efficient collection systems must handle 5,000–10,000 tonnes/year to be viable (Deng et al., 2024).
• Policy Gaps: With landfill costs as low as $4.40 per panel versus $28 for recycling, current regulations do not incentivise recovery (University of Sydney, 2023). National policies are needed to mandate recycling and support circular solutions.

Conclusion

The rise in end-of-life PV panels presents a challenge but also a significant opportunity to recover valuable materials, particularly silicon. Much of this is currently lost to landfill, causing both environmental and economic waste. However, advanced recovery methods achieving purities up to 99.999% exist and are viable. These technologies enable high-value reuse in solar cells (at 19.7% efficiency) and lithium-ion batteries.

With policy support and infrastructure development, Australia can turn its solar waste crisis into a circular economy opportunity, potentially recovering over $1 billion in resources by 2035 (Deng et al., 2024).

References

• CSIRO. (2024, May). Supplementary report: Silicon. From minerals to materials: Assessment of Australia's critical mineral mid-stream processing capabilities. CSIRO, Canberra.
• CSIRO. (2025). Australian silicon action plan. https://www.csiro.au/en/research/natural-environment/critical-minerals/australian-silicon-action-plan
• Deng, R., Dias, P. R., Schmidt, L., Chang, N. L., & Lunardi, M. M. (2024). High yield, low cost, environmentally friendly process to recycle silicon solar panels: Technical, economic and environmental feasibility assessment. Renewable and Sustainable Energy Reviews, 169, Article 112900. https://doi.org/10.1016/j.rser.2022.112900
• Fraunhofer Institute for Solar Energy Systems ISE. (2022, February 7). PERC solar cells from 100 percent recycled silicon. https://www.ise.fraunhofer.de/en/press-media/press-releases/2022/solar-cells-from-recycled-silicon.html
• Innovating the recycling of silicon-based solar panels with an eco-friendly alkaline leaching process. (2024). Resources, Conservation and Recycling, 211, Article 107887. https://doi.org/10.1016/j.resconrec.2024.107887
• Lee, J., Duffy, N., & Allen, J. (2025). A review of end-of-life silicon solar photovoltaic modules and the potential for electrochemical recycling. Advanced Energy and Sustainability Research, 6(2), Article 2400254. https://doi.org/10.1002/aesr.202400254
• Monaghan, T. (2025, March 6). Australia’s solar waste: A growing problem. Australian Energy Council. https://www.energycouncil.com.au/analysis/australia-s-solar-waste-a-growing-problem/
• Naseer, M. N., Serrano-Sevillano, J., Fehse, M., Bobrikov, I., & Saurel, D. (2025). Silicon anodes in lithium-ion batteries: A deep dive into research trends and global collaborations. Journal of Energy Storage, 111, Article 115334. https://doi.org/10.1016/j.est.2025.115334
• University of Sydney. (2023, September 13). Australia faces solar waste crisis. https://www.sydney.edu.au/news-opinion/news/2023/09/13/australia-faces-solar-waste-crisis.html
• UNSW Sydney. (2024, March). Bigger and better solar panel recycling centres needed to deal with PV waste, says report. https://www.unsw.edu.au/newsroom/news/2024/03/Bigger-better-solar-panel-recycling-centres-needed-deal-PV-waste-report