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Recycling is of significant importance in a circular economy, but there are some challenges to be faced when it comes to recycling PV modules. The novel Hot Knife method of separating the crystalline silicon PV module front glass from the backsheet contributes only a few permill to the potential environmental impacts associated with the life cycle of PV electricity.
Recycling has emerged as a fundamental element in forging a circular economy within the photovoltaic (PV) industry, enabling a sustainable and resource-efficient future. While the durability of PV modules presents a challenge for recycling efforts, a novel solution has emerged in the form of the Hot Knife method. In collaboration with a leading technology manufacturer, Task 12 of the International Energy Agencys Photovoltaic Power Systems Program (IEA PVPS) has published a new report that provides a comprehensive assessment of the environmental life cycle of this innovative photovoltaic technology. photovoltaic recycling.
Recycling: A cornerstone of the circular economy for PV
As the number of PV modules out of service increases, responsible end-of-life management of modules becomes essential to minimize waste and maximize energy recovery. resources. Recycling not only conserves valuable materials, but also significantly reduces the industrys environmental footprint, making it a key driver of sustainable growth.
Photovoltaic modules are designed to withstand harsh environmental conditions for decades, demonstrating the robustness and longevity of these devices. However, this same durability poses challenges in the recycling process. One of the most formidable obstacles is the intricate task of separating the glass from the other layers of the module. Traditional recycling methods often struggle to delaminate PV modules efficiently and economically, so a different approach is needed.
Introducing the Hot Knife Method: A Novel Solution
The Hot Knife method stands out as an innovative and cutting-edge solution to the challenge of delamination. Through heat treatment, this novel technique melts the polymers that bind the glass to the cell/ethylene-vinyl acetate (EVA) backsheet, facilitating the separation process. The previous treatment steps also manage to eliminate the junction box, the cables and the aluminum frames. The materials that can be effectively recovered are aluminum sheets and glass, as opposed to contaminated crushed glass, the product of other recycling techniques. Other components that are sold for further treatment/recovery are copper wires and cell/EVA backsheets. As a result, the Hot Knife method not only streamlines recycling efforts,
Collaboration on IEA PVPS Task 12: Assessment of Life Cycle Related Environmental Impacts
Recycling processes are most valuable if their contribution to the overall environmental footprint of the system is low. IEA PVPS Task 12, in collaboration with a leading manufacturer of photovoltaic technology, embarked on the task of evaluating the environmental impact of the Hot Knife method.
The “ Life Cycle Assessment of Crystalline Silicon Photovoltaic Module Delamination with Hot Knife Technology ” report delves into the broad scope of life cycle assessment , covering all stages of the Hot Knife recycling process. From the extraction of the material to the manufacture of the module, through its use and subsequent recycling, the LCA offers a holistic evaluation of the environmental impacts associated with the Hot Knife method. The environmental impacts caused by the delamination process are attributed to the recovered materials and are compared to the environmental impacts caused if these materials were produced from primary resources.
The reports conclusions underscore the impressive environmental efficiency of the Hot Knife method. Efficiently recovers aluminum and glass and separates the backsheet (containing cells/Ethyl Vinyl Acetate (EVA)). According to data measured by the manufacturer, the use of this technology contributes 0.3% or less to the environmental footprint related to the life cycle of PV electricity in any impact category. Also, compared to the environmental impacts of virgin materials, the environmental impacts of reclaimed materials are 80-98% lower depending on the impact category. In particular, the recycling process significantly reduces energy consumption, greenhouse gas emissions and the global environmental footprint compared to the corresponding primary materials. Furthermore, the recovery of valuable materials highlights the potential for greater resource efficiency within the PV industry.
Thanks to its high environmental efficiency, this technology is currently used in one of the largest commercial-scale photovoltaic recycling facilities in the world (ENVIEs in Saint Loubès, France), as well as in some facilities in Japan. Building on this initial experience, further improvements such as increased consumables and energy efficiency can be expected as this technology is implemented in other applications and scaled up to larger volumes.
Conclusion
In our efforts to build a cleaner and greener future, photovoltaic recycling is emerging as a fundamental pillar in the transition towards a sustainable energy landscape. As the Task 12 report demonstrates, the Hot Knife method represents an innovative approach to address the challenges of recycling PV modules in an environmentally efficient way. However, some aspects had to be excluded from the Task 12 study due to lack of available data, including treatment of copper cables, backsheet treatment, and recovery of copper and silver during these treatments. These processes still need to be added in a future life cycle assessment study. |
