Photovoltaic (PV) Recycling, Reusing, and Decommissioning
Photovoltaic (PV) modules are used worldwide as a source of renewable electricity. They can play a significant role in reducing the use of fossil energy sources.
In recent years, technology advancement and increased manufacturing capacity have led to the falling cost of PV modules and have made solar energy costs comparable to other sources of electricity. This has resulted in an exponential growth in solar energy adoption globally.
In North America, the cumulated installation of PV modules was approximately 80 GW by the end of 2019. It is estimated in this report that the installation could increase up to 437 GW by 2030. With an average lifespan of 30 years for each PV module, a significant amount of waste is expected to be generated and could reach 27,000,000 tonnes in the years to come. Therefore, end-of-life management of PV modules is an essential part of making sure clean solar energy is a sustainable solution for the future energy economy.
Most of the PV modules in the North American market are made of crystalline silicon solar cells encapsulated in a polymer matrix behind glass and framed with aluminum, and the waste would mostly include glass, polymer, aluminum, copper, silicon, and silver. Without treatment, there is risk that these materials will leak into the ground if PV panels are landfilled, which will have a negative impact on the environment. Additionally, it is expected that up to 70% of used modules may still be functional, though some degradation might have taken place, and could still be reused or refurbished to give them a second life. The main markets are expected to be outside North America. However, even if panels are sold for reuse, sound decommissioning processes and transportation will be important to avoid leakage of materials into the environment.
Currently, specific legislation to manage the recycling and treatment of end-of-life PV modules in North America does not exist, but some federal states in the United States have introduced PV module regulations or have initiated a regulatory process. The regulations differ between states and the regulatory framework is rather fragmented. There is a similar situation in Europe which has a waste electronic electrical directive and individual national transpositions that require detailed knowledge to ensure full compliance with the rules but often through different processes. A fragmented framework can have a negative impact on recycling. For instance, in the United States, modules can be transported from one state that has regulations in place to another state that does not have regulations and that will allow the modules to be landfilled without treatment. Harmonized legislation and common standards could help to establish sound and equal rules and thus save overhead and compliance costs.
The PV industry, the waste treatment industry, and governments and authorities should develop the necessary policies and legal frameworks together to tailor solutions for the development of the PV market and waste industry in North America. Environmentally friendly renewable energy technologies can utilize modern approaches like Eco-Design, Product Environmental Footprint, and stewardship standards that include a sound circular economy strategy to save valuable resources and meet zero waste demands as much as possible.
There are only a few standards related to PV modules, and the most comprehensive one is NSF/ANSI 457 Sustainability Leadership Standard for Photovoltaic Modules and Photovoltaic Inverters. It provides sustainability performance criteria and corporate performance metrics to create high sustainability in the PV market. It helps the purchaser to identify sustainable and environmentally friendly products. However, there are still more opportunities for the development of standards as this standard does not cover the whole PV recycling and reusing process. Standardization and international harmonization of standards and best practice guidelines will contribute to improving PV waste management and to saving costs.
For instance, it has been identified in a recent study that there is no consistency of data pertaining to PV modules put in the market in Europe leading to the recommendation to harmonize international data reporting . Adequate and consistent tracking of the renewable energy system transformation can support the development of sound cradle-to-grave or even cradle-to-cradle solutions, and can also provide reliable statistical data for not only governments and authorities but also for stakeholders of the value chain, including manufacturers, installers, and plant operators, and repair and refurbishment, waste collection, and recycling plants.
The conclusion discussed the gaps that have been identified and support a more sustainable use of PV modules. They include standardization of decommissioning, collection, pretreatment, waste treatment processes, and monitoring and quality control. These standards can help encourage investment into value-retaining high-quality recycling and reusing processes to be established with a good eye to meeting both the growing demands of the waste market and the environmental protection targets.