Solar panels make it possible to generate sustainable energy, thus contributing to relieving the burden on the environment. At the same time, traditional solar panels are little to no recyclable at the end of their useful life. In the EU Horizon project PILATUS, a consortium of 19 companies and research institutes is therefore working on recyclable solar panels.
The consortium - consisting of 19 companies and research institutes - is working on an alternative design for solar panels in which individual components and materials are more accessible. This should enable recycling of the components.
Rear contact cells
Within the PILATUS project, the parties are working on a pilot line for the production of heterojunction silicon solar cells with back-contact technology (interdigitated back-contact / IBC). Back-contact cells have the potential to achieve the very highest efficiencies for single silicon, reports TNO.
TNO previously developed the so-called 'release encapsulant', and is involved in PILATUS from this role. The encapsulant forms a connection layer for embedding solar cells in the solar module, and also ensures mechanical integrity. At the end of its lifetime, however, the material is difficult to remove in traditional solar panels.
4,000 tonnes of solar panels go into the shredder every year
In practice, this means that many solar panels that have reached the end of their useful life end up in the shredder and are crushed into filler material for use in (road) construction. Within the European Union (EU), around 4,000 tonnes of solar panels are involved on an annual basis.
In addition, the quantity is rising due to the increasing number of solar panels. In the Netherlands, for instance, an estimated quarter of a million panels will be eligible for removal by 2030. Worldwide, it is estimated that 10 billion solar panels, with a combined weight of 60 million tonnes, will be involved by 2050.
From crushing to recycling
Earlier, a nationally funded project called DEREC was carried out. In this project, TNO already showed that it is possible to dismantle solar panels responsibly. Within the PILATUS project, the parties are applying this method to Meyer Burger's heterojunction silicon solar panels with rear contact technology (IBC SHJ).
The project aims to enable the development of circular solar panels on European and US soil. It should thus help reduce dependence on Asia. "The intention is to eventually produce circularly designed solar panels in Europe," says Martin Späth, Senior Scientist at TNO. "Good for the environment and for creating new business. From the EU, legislation is on the way: the Net Zero Industry Act (opens in new window) (links to another website) and the Critical Raw Materials Act (opens in new window) (links to another website), aimed at producing circular products with reduced greenhouse gas emissions. In the PILATUS project, we are working with companies that are already working hard on this themselves. We need to move from 'weight towards value', or from tons of waste to recovering and reusing valuable materials such as glass plates for solar panels, silicon and silver."
European factory
Switzerland's Meyer Burger, supplier of machinery to produce solar cells, is coordinator of the PILATUS project. Meyer Burger will build a plant based on the new IBC SHJ technology. Norwegian Crystals (NCR), also involved in PILATUS as a partner, will supply the 'wafers' that form the base material for making the solar cells. A modified manufacturing process for the solar cells makes the 'waste' created in the shaping sawing of the wafers fully reusable to produce new heterojunction solar cells.
"The combination of knowledge and practice in the cooperation between the parties in this project will put Europe at a global lead. In Asia, huge investments have been made in technologies that we want to move away from here precisely because solar panels are not easily recyclable," Späth said.
Practically feasible and cost-effective dismantling process
"TNO has a particular focus on circularity through specific attention to application of 'closed loop' materials and dismantling a solar panel into pure components for further targeted recycling thereof. Among other things, we test the fabricated solar panels in our climate chambers with the aim of a practically feasible and cost-effective dismantling process."
Further information on the PILATUS project is available here.
Author: Wouter Hoeffnagel
