Expert Talk: The Sustainability of Photovoltaic Solar Energy: an overview

As already said, PV energy is geared up for immense growth in the coming decades, which can only be enabled in a sustainable manner thanks to constant innovation. Solar PV has been generally identified as the most important renewable energy technology for cost optimized climate change mitigation. It is estimated that it will require installing a total of 20 to 80 TWp[2] of PV until 2050 and 80 to 170 TWp until 2100 to remain compatible with limiting climate change to 1.5 °C [4]. Such huge numbers are going to challenge various LCA impact categories. We will briefly discuss the critical ones: Integration, land use planning, recyclability, use of resources and local production. Rationally, all these are examined at EnergyVille.

• Since land area is scarce and there will be a huge growth of PV installations, PV systems need to become seamlessly integrated in the urban environment and need to obtain dual functions (electricity generation plus other function). As an example, traditional ground mounted solar installations on farmland need to be avoided, since arable land is then removed from potential agricultural use. Instead, integration and dual (land) use are optimized via the development of agricultural (agri), building-integrated (BI), floating (F) and infrastructure-integrated (II) PV systems.
• Recycling needs to be increased from the current 85% to 100%. The EU Waste Electrical and Electronic Equipment directive addresses the waste management of all electronics in the EU, and currently requires 85%/80% (recovery/recycling rate) of waste PV modules by mass to be recycled. Hence most PV modules are not yet designed for full circularity (i.e., easy to disassemble, repair, refurbish and recycle). Very recently, several initiatives are already claiming 100% recyclability (e.g., Solarge in the Netherlands). Another important aspect is to expand the lifetime of PV modules, which is always favourable from an environmental perspective [5].
• All resources need to be reconsidered at TW-scale. Based on the current technology, a giant PV industry would be running into resource constraints concerning e.g. energy, float-glass, capital investments, silver, indium, and bismuth. It has been shown that continued technological learning at current rates would be sufficient to stay within reasonable resource boundaries. Even more, technological solutions enabling such learning are foreseeable. These technology improvements are expected to bring the greenhouse gas emissions for PV in the range of 5 g CO2 eq./kWh [4,6], in line with values for nuclear energy.
• Production needs to come back to Europe. The projected growth facilitates scaling up the European solar PV industry value chain to capture booming local demand. In 2020, around 20 GWp was installed in Europe, and a strongly growing European market is estimated for the next decade. At the same time, European companies and research centres have been developing world-leading cell and module technologies, as well as applications for buildings, water, and agricultural land. The European Solar Initiative sets the goal of redeveloping 20 GWp of PV manufacturing in Europe by 2025 [7].