Shedding light on decommissioning solar panel streams: A system dynamics model for volume estimation

• There is a need to introduce dynamism in variables that require doing so to provide more realistic estimations of future “waste” volumes. • Decommissioned solar panels are both new and old, functional and non-functional panels present in diverse quantities and with their particular remaining efficiency and age. • Solar panels do not get decommissioned exactly after 30 years, but their decommissioning happens throughout time. This means that the decommissioning curve is not a delayed representation of the installation base but that the volumes of decommissioning panels spread throughout time in a flatter manner. • The expected increase in repowering practices in the near future could bring high volumes of decommissioned panels earlier in time. This has practical implications as the industry might experience high volumes of functional and non-functional panels already in the next few years. The global expansion of solar energy presents a paradox: while it is a key sustainable technology, a comprehensive waste management strategy for decommissioned solar panels remains insufficient. Previous studies have examined this issue, yet waste volume estimations remain incomplete due to the exclusion of early waste streams and the failure to account for temporal fluctuations in key variables. This study addresses these gaps by employing System Dynamics Modelling (SDM) to capture a more nuanced understanding of the heterogeneity of decommissioned panels. The findings reveal significant discrepancies between projections from conventional static models and those generated by the developed model, underscoring the need for more adaptive forecasting methods that account for temporal variations and the evolving characteristics of decommissioned panels. Furthermore, this paper highlights the inefficiencies of uniform waste management approaches, emphasizing the need for differentiated strategies based on panel characteristics. Crucially, the findings challenge the recycling-centric paradigm by exposing the overlooked potential of functional discarded panels, advocating for circular strategies that prioritize reuse and secondary markets.