Could cannabis help clean polluted soil under solar panels?

Over the past century, industrial activities have caused widespread soil contamination by potentially toxic elements (PTEs), making effective remediation increasingly urgent. Phytoremediation offers a sustainable strategy using selected plant species to remove, stabilize, or sequester pollutants. This study proposes an integrated agrivoltaic-phytoremediation framework for remediating PTE-contaminated soils. The framework integrates literature-based plant selection, photovoltaic system simulations, and techno-economic assessment, demonstrated through a representative case study in Augusta (Sicily, Italy). The effects of photovoltaic shading on C3 and C4 crops, together with PTE contamination, were estimated from literature data to quantify biomass reduction. A quantitative assessment was then performed by integrating literature data with PVsyst simulations of different photovoltaic configurations. The results indicate that the optimal configuration depends on the specific system objectives, such as maximizing energy production or biomass yield. Three agrivoltaic configurations, each combining a different photovoltaic technology with a selected plant species, were evaluated through a techno-economic assessment considering energy production, biomass yield under varying shading conditions, and net economic returns. The monofacial/Arundo donax L., bifacial/Chrysopogon zizanioides (L.) Roberty, and semi-transparent/Cannabis sativa L. configurations achieved annual energy productions of 568,660, 297,987, and 285,638 kWh, respectively, with corresponding biomass yields of 26.3, 60.0, and 14.0 t ha-1 year-1 and net economic returns of €2,906, €6,730, and €1,543 ha-1 year-1.