Impacts of solar panels on vegetation biomass shift with climate aridity

The rapid expansion of ground-mounted photovoltaic solar panels, however, has aroused concerns of negative impacts on ecosystems. Based on a global meta-analysis of 55 paired field observations across 55 sites, we show that solar panels exert divergent impacts on aboveground biomass in the under-panel area compared with the gap area dependent on the trade-off between a shading effect and altered water relations.

Specifically, solar panels on average cause a significant decrease of under-panel aboveground biomass by 20% (-32%~-6%) in regions with aridity index (annual precipitation/potential evapotranspiration) above 0.22, whereas no significant effect is found for regions with aridity index below 0.22. Using a criterion of aridity index below 0.22, we identify a global dryland area of 11.28 million km2 where aboveground biomass is not declined by the presence of infrastructure for photovoltaic solar power generation.