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Designing a Recycling Strategy for a Greener Generation of Solar Panels
- There are currently two main types of solar panels: silicon-based and thin-film-based. Both can be successfully recycled with some research that has reached 96% recycling efficiency intending to further improve.
- Most countries have policies that place solar panel waste under the general waste classification—except the European Union. Solar panel waste management is regulated under a strict directive that requires all manufacturers supplying solar panels to the EU market to cover the cost of collecting and recycling all end-of-life panels.
- The renewable energy industry, governments, and other stakeholders will need to prepare for the anticipated large volumes of waste photovoltaic (PV) panels. With the right policies and supporting frameworks, there is potential for creating innovative industries that recycle and repurpose old solar PV panels.
The energy industry is transitioning towards a more sustainable future. However, not all renewable sources remain environmentally friendly at the end of their life cycle. This is one of the most widespread concerns in the solar industry and an area they are pursuing to improve.
The majority of studies have learned that the life expectancy of solar panels is around 30 years before decommissioning. However, during a solar panel’s life, a 20% decrease in power capacity can occur. Between the first 10 to 12 years, the maximum decline in efficiency is 10% and pushes 20% when reaching 25 years. The majority of manufacturers guarantee these figures.
Once these panels are no longer generating power efficiently, there is then the issue of what should be done with the obsolete systems. Recycling the materials is the most obvious environmentally friendly option, but the processes are expensive and lack the infrastructure to facilitate widespread practice. This article explores the current end of the life management process and what can be done to ensure solar panels are recycled in the future.
Current Solar Panel Recycling Processes
Some research has reached an astounding 96% recycling efficiency, but the aim is to improve this further to make the solar industry genuinely sustainable.
The research studies conducted on solar panel recycling have resulted in numerous new technologies. Some research has reached an astounding 96% recycling efficiency, but the aim is to improve this further to make the solar industry genuinely sustainable.
There are currently two main types of solar panels—silicon-based and thin-film-based— requiring a different recycling approach. Positively, both types can be recycled using distinct industrial processes. At this time, silicon-based solar panels are more typical of the two—although this does not mean that there is not great potential value in the materials found in thin-film-based solar cells.
- Silicon-Based Solar Panel Recycling
The silicon-based PV panel recycling process begins with disassembling the panel to separate the aluminum and glass parts. Around 95% of the glass can be reused, while all external metal parts can be remoulded into cell frames.
The rest of the materials are treated at 500°C in a thermal processing unit, easing the binding between the cell elements. The intense heat causes the encapsulating plastic to evaporate, leaving the silicon cells ready to be processed further. This recycling method ensures that the plastic is not wasted as it is reused as a heat source for additional thermal processing.
Following the thermal process, the green hardware is physically separated. Around 80% of these can readily be reused, while the remainder requires further refinement. Next, the silicon particles (known as wafers) are removed using acid. The broken wafers are then melted down to be used again for manufacturing new silicon modules, resulting in an 85% recycling rate for the silicon material.
- Thin-Film-Based Solar Panel Recycling
Compared to silicon-based PV panels, thin-film-based panels are processed much more drastically. First, they are shredded and then run through a hammermill to ensure all particles are no larger than 4-5mm—the size where the lamination keeping the inside materials together breaks. Also, unlike silicon-based PV panels, the remaining substance comprises both solid and liquid material. Next, a rotating screw separates the two materials, which keeps the solid parts rotating within a tube while the liquid trickles into a container below.
The collected liquid is then purified via a precipitation and dewatering process. The substance then goes through a metal treatment to entirely separate the various semiconductor materials. As a result, an average of 95% of the semiconductor material can be reused. However, the reusable percentage will depend on the actual technology used when manufacturing the original panel.
The solid materials are contaminated with what is known as interlayer materials. These interlayers are lighter in mass and can be removed using a vibrating surface. Lastly, the ma solid mass goes through a rinse. It is pure glass that is left behind, saving 90% of the glass elements for remanufacturing.
As fantastic as solar panel recycling potential is, solar end-of-life management offers opportunities relating to all “three Rs” of sustainable waste management—reducing, reusing, and recycling. Here are examples of how the three Rs can be applied to solar panel waste management:
As research and development and technological advances progress throughout the solar industry, the structure of solar panels is expected to need fewer raw materials.
The rapid global solar market growth will create a robust secondary market for panel components and materials.
As existing solar panel installations reach the final decommissioning phase, recycling and material salvage will be preferable to panel disposal.
Solar Panel Disposal Regulations
Many lessons can be learned from the EU’s experience in creating their regulatory framework—it could help other countries develop similar locally appropriate solar panel recycling policies.
For most of the world, regulatory obligations place PV panel waste under the general waste classification. This has a substantial environmental impact when it comes to managing solar end-of-life management. Currently, the sole exception exists at a European Union (EU) level, where PV panels are classified as e-waste in the Waste Electrical and Electronic Equipment (WEEE) Directive. Solar panel waste management is regulated under this directive and other legal frameworks in EU member states.
In a few cases, such as in the USA and Japan, general waste regulations include solar panel testing to check for hazardous material content, along with prescription or prohibition of specific shipment, treatment, recycling, and disposal pathways. This is not the same extent as the EU, which has pioneered PV electronic waste (e-waste) regulations. Their policies cover PV-specific collection, recovery and even recycling targets.
Based on the extended-producer responsibility principle, the EU’s WEEE Directive demands all manufacturers supplying PV panels to the EU market must cover the cost of collecting and recycling all end-of-life PV panels put on the European market. Many lessons can be learned from the EU’s experience in creating their regulatory framework—it could help other countries develop similar locally appropriate solar panel recycling policies.
The Future of Solar Panel Recycling
With the right policies and supporting frameworks in place, there is massive potential for creating new industries that recycle and repurpose old solar PV panels.
To create a robust solar panel recycling system, the renewable energy industry, governments, and other stakeholders will need to prepare for the anticipated large volumes of waste PV panels. This can be established in the following three main ways:
- Implement PV-Specific Waste Policies
Sustainable end-of-life management regulations for solar panels can best be accomplished by enabling a regulatory framework, along with the institutions required to enforce it. More data and analyses are needed at a national level to help support such regulatory and investment requirements.
- Expand the Waste Management Infrastructure
There is no one-size-fits-all approach to solar panel recycling. There is a need for management schemes for solar waste to be tailored to fit the unique circumstances of each country or region. For this to work, coordination processes between the energy and waste sectors are essential to support PV end-of-life management.
- Encourage Ongoing Innovation
Research and development and skill progression are necessary to establish additional value creation from PV end-of-life panels. In the coming years, policy-makers and solar stakeholders will need to prepare for the rise of panel waste and design systems to capitalize on the potential resulting opportunities.
With the right policies and supporting frameworks, there is massive potential for creating innovative industries that recycle and repurpose old solar PV panels. As a result, it can generate considerable economic value creation and become an essential element in the world’s shift to a renewable energy future.
Although solar experts recognize that solar panels can be recycled, there is not yet a robust solar panel recycling infrastructure established. This will need to be implemented in the near future to handle the large volumes of PV modules that will need to be discarded over the coming years.
Once solar panel recycling becomes standard practice, it will lead to several positive environmental factors, along with new economic opportunities. For example, PV recycling will create more green job opportunities and approximately $15 billion in recoverable solar panel materials value by 2050.
The arrival of recycled solar materials will make it possible to produce around 2 billion new solar panels without investing in new raw materials. This indicates that it will be possible to generate around 630 GW of energy from reusing old solar panel materials.
More households, businesses, and green investors choose to invest in solar power technology due to the continuing drop in solar energy prices. This will inevitably result in more economic opportunities emerging in the solar cell recycling sector.
Frequently Asked Questions (FAQs)
Can solar panels be recycled?
It is feasible to recycle solar panels as the components are made from three primary materials – glass, silicon, and metal. However, there is an urgent requirement for a more substantial infrastructure to collect, process, and repurpose the equipment. As a result, many of the world’s obsolete solar panels are going to landfill.
What percentage of a solar panel is recyclable?
Many studies have been performed to test how best to recycle solar panels, resulting in new technologies. Some studies have achieved an astounding 96% recycling efficiency, but solar scientists aim to raise the bar higher and make solar panels completely recyclable.
What is the lifespan of a solar panel?
Unfortunately, we do not yet have solar panels that can generate power forever. The standard lifespan of a solar panel is around 25 to 30 years. This has resulted in many of the panels installed during the early end of the current solar boom will soon be reaching their end-of-life and will need replacing.
Are solar panels environmentally friendly?
Solar panels are incredibly environmentally friendly when compared to other power sources that use fossil fuels. Each household that switches over to solar energy stops around 7.7 tons of toxic greenhouse gases from being admitted. However, while solar is recognized as a green energy source, some adverse environmental effects still exist. For example, photovoltaic (PV) panel production has been linked to carbon emissions, toxic waste, unsustainable mining practices, and habitat loss.
What is the future of solar panels?
Soon, technology improvements will allow for solar systems to become even cheaper. As a result, it is possible that by 2030, solar power will become the most important source of energy for electricity production in most of the world. The switch to solar power will also have a positive impact on the environment and climate change.