Assessment of Interstitial Woody Plantings in North–South Axis Solar-Tracking Photovoltaic Systems: Balancing Shading Impact and Landscape Integration

This paper evaluates the feasibility of integrating interstitial woody plantings into north–south axis solar-tracking photovoltaic (PV) systems in Spain to enhance landscape integration while minimizing shading. A computational model based on a typical PV plant geometry (13.5 m row spacing and 2.42 m rotation axis height) is developed to simulate tree canopy interactions. Focusing on an intermediate “limiting plane” set at 23° from the panels’ lower edge, the model calculates shade duration and coverage under varying sun elevations throughout the year. Trees with a crown diameter of 1.2 m and a total height of 3.04 m, spaced 4 m apart, cast shadows for approximately 46 min each morning and afternoon, resulting in an average 3.3% panel occlusion and a peak shadow intensity of 33.6% on specific days, declining to 32% after one month. Shading intensity remains modest during early morning and late afternoon hours, when solar irradiance is lower, further reducing potential energy losses. The crowns’ diffuse nature mitigates shadow effects. The findings suggest that medium-height tree plantings can provide ecological, aesthetic, and social benefits while incurring minimal impact on energy yield in agrivoltaic systems. The study underscores the importance of selecting planting height and spacing according to solar path and tracker geometry. Future research should validate the model under operational conditions and evaluate the dual benefits for renewable energy output and plant growth.